Title of Invention	REINFORCEMENT MEMBER FOR A BUSHING TIP PLATE AND METHOD OF REINFORCING THE PLATE
Abstract	In a bushing assembly having a plate like structure comprising a plurality of orifices for forming fibers from a fluid mater, a number (10a, 10b) for reinforcing the structure comprising:- A T-shaped structural body having a first portion (12) having a profile with variable height comprising a least one Apex (A); whereby the variable profile and the atleast one apex of the body assists in reinforcing the structure against sagging and extends the service life thereof while minimizing metal usage.

Title of Invention

REINFORCEMENT MEMBER FOR A BUSHING TIP PLATE AND METHOD OF REINFORCING THE PLATE

Abstract

In a bushing assembly having a plate like structure comprising a plurality of orifices for forming fibers from a fluid mater, a number (10a, 10b) for reinforcing the structure comprising:- A T-shaped structural body having a first portion (12) having a profile with variable height comprising a least one Apex (A); whereby the variable profile and the atleast one apex of the body assists in reinforcing the structure against sagging and extends the service life thereof while minimizing metal usage.

Full Text	REINFORCEMENT MEMBER FOR A BUSHING TIP PLATE AND METHOD OF REINFORCING THE PLATE TECHNICAL FIELD AND INDUSTRIAL APPLICABILITY OF THE INVENTION The present invention relates generally to bushings for forming fibers from a fluid material, such as glass at an elevated temperature and more particularly, to an improved manner of reinforcing a bushing tip plate to extend the service life thereof. BACKGROUND OF THE INVENTION Various types of bushings or bushing assemblies for forming fibers or filaments from a fluid material, such as glass at an elevated temperature, are known in the art. Usually, the bushing or bushing assembly includes a rectangular bushing body having sidewalls and end walls. Together, the side and end walls serve as a frame for supporting or carrying one or more, often elongated plate-like structures, typically formed of platinum or alloys thereof, having a plurality of small orifices or "tips." These tips receive the molten material as it passes through the bushing body from an upstream source, such as a forehearth. To assist in keeping the material in a molten state as it enters and passes through these tips, the plates are heated, usually by electrically coupling them to a source of high current, such as a transformer. As molten glass material streams exit the tips, they are mechanically drawn to form continuous fibers which are wound onto mandrels or creels or directly chopped for later processing or use. A detailed description of the basic apparatus and methodology used is found in commonly assigned U.S. Patent Nos. 5,709,727 to Bobba and 3,920,430 to Carey, the disclosures of which are incorporated herein by reference. To improve the output and efficiency of the overall fiber-forming operation, it is of course desirable to maximize the number of fibers created by the tip plate. To do so, a tip plate can in theory be made infinitely large in both the width and length dimensions. However, several well-recognized problems arise, especially when the width dimension of a tip plate is significantly increased relative to the length dimension. Perhaps the most prevalent problem resulting from increasing the dimensions of the tip plate, and in particular, the width dimension, to the degree necessary to realize a significant increase in fiber output is a sharp reduction in the service life. The tip plate is normally rectangular in top plan view, with its four side edges welded directly to the opposed side and end walls of the rectangular bushing body. When the width dimension of the tip plate increases relative to the length dimension, the plate essentially acts as a simple beam supported at the sides and ends, with no direct support at the "middle" (that is, the portion furthest from the side and end walls of the corresponding bushing body). Significant bending stresses acting on the tip plate as the result of prolonged contact with the heavy molten material over time results in sagging due to time dependent plastic deformation, or creep. This sagging is deleterious primarily because it results in non- uniform thermal distribution and the concomitant production of fibers having substantially different diameters across the tip plate. That is, the extremes in temperature cause some bushing tips to become too cold to attenuate a fiber and others are hot enough to cause a forming instability. Both cases cause fiber breakage and a loss in conversion efficiency. Reducing the width dimension of the plate is therefore desirable to curtail the effects of creep and increase the service life. However, the trade-off is an undesirable reduction in output and a concomitant increase in cost when only a single narrow-width tip plate is used. Also, after prolonged use, even a single narrow-width tip plate eventually suffers from creep-induced sagging, non-uniform fiber output, and increased fiber break rates. In an effort to increase the service life of a bushing tip plate to overcome this problem and others, the present Assignee has in the past employed reinforcing members formed of platinum or a platinum alloy, termed "gussets." These gussets usually extend width-wise across the upper surface of the tip plate (that is, between the sidewalls of the bushing body) at spaced intervals, and typically have a cross-section that corresponds in shape to a "T" or inverted "L." In use, me depending "leg" formed by the web of each gusset is secured directly to the upper surface of the tip plate, such as by laser or tungsten- inert gas (TIG) welding. While these gussets do serve to extend the service life of the tip plate, including even in the narrow-width case, the degree of the benefit gained is somewhat limited. In particular, the gussets having a T-shaped or inverted L-shaped cross-section are also susceptible to sagging due to bending stresses and creep as the underlying tip plate. This is because the gusset, while providing some reinforcement strength, also behaves like a simple beam, and thus experiences maximum deflection at the span midpoint as in an unsupported tip plate. In other words, despite the reinforcement, the maximum or peak stress and hence, the maximum or peak sag, still occurs at the middle of the tip plate away from the side and end walls. Accordingly, a need for an improved manner of reinforcing tip plates, including those existing bushing designs (with or without gussets) with an eye toward further extending their service life is identified. SUMMARY OF THE INVENTION In accordance with a first aspect of the invention, a reinforcement member for a bushing assembly having a plate-like structure including a plurality of orifices for forming fibers from a fluid material is provided. The member comprises a body including a first portion for attachment to the structure and a second portion having a profile with a variable height including at least one apex. The variable height profile and the at least one apex of the body assists in reinforcing the plate-like structure against sagging and extends the service life thereof without undue alloy usage. In one embodiment, the reinforcement member is comprised of a single piece of material, with the body including the first and second portions having an inverted L- shaped, T-shaped, or F-shaped cross-section. The profile of the second portion of the body may have an inverted V-shaped, inverted W-shaped, or arcuate profile. Preferably, the body has a length including a midpoint, with the at least one apex located substantially at the midpoint. The midpoint may also be the midpoint between the spaced sidewalls or external support points of the bushing assembly to which a first and a second end of the body are secured. In other embodiments, the body comprises a first member defining the first portion for attachment to the structure and a second member coupled with the first member, defining the second portion and having the variable height profile with the at least one apex. The first member may have a T-shape or an inverted L-shape in cross-section. Likewise, the second member may have a T-shape or an inverted L-shape in cross-section, and may be formed from one or more component parts. Additionally, the second portion may have an arcuate profile, an inverted V-shaped profile, or an inverted W-shaped profile, each including the at least one apex. Preferably, the second member includes a web having an end that is welded directly to an upper surface of the first member, and optionally may have a profile that defines two or more apexes. In any of the embodiments, either the first or second portion of the body may include a plurality of strategically positioned openings. These openings serve to reduce the amount of material required to fabricate the reinforcement member without compromising the strength thereof. In accordance with a second aspect of the invention, a bushing assembly for use of forming a plurality of fibers from a fluid material at an elevated temperature is disclosed. The assembly comprises a structure having a plurality of orifices through which the fluid material passes to form the fibers and at least one reinforcement member. This member comprises a first portion for attachment to the structure and a second portion having a profile with a variable height including at least one apex. The variable height of the reinforcement member including the at least one apex enhances the ability of the structure to resist sagging and extends the service life thereof while minimizing the amount of precious metal used for reinforcement The fiber forming structure is typically plate-like, with different width and length dimensions to form a rectangular shape. In one embodiment, at least one reinforcement member extends along a width dimension of the plate, and preferably a plurality of independent, spaced reinforcement members extend width-wise along the plate-like structure. The fiber-forming structure also has an upper surface (the molten glass material contacts this surface) to which the first portion of each reinforcement member may be welded. Each reinforcement member maybe fabricated from either a single piece of material or at least two pieces of material secured together, such as by welding. In accordance with a third aspect of the invention, a reinforcement member portion for use in a bushing assembly having a fiber-forming tip plate including at least one existing gusset is provided. The reinforcement member portion comprises a body for attachment to the gusset and having a profile with a variable height including at least one apex. The variable height and the at least one apex of the reinforcement member portion assists in reinforcing the gusset and hence, at least the adjacent portion of the tip plate, against sagging, which extends the service life thereof while minimizing the amount of precious metal used for reinforcement. In one embodiment, the gusset has a substantially planar upper surface and the body of the reinforcement member portion includes a web having a first end that is welded to the upper surface of the gusset. The body may have a T-shaped or inverted L-shaped cross section, and the profile of the body may be selected from an arcuate profile, an inverted V-shaped profile, or an inverted W-shaped profile. In accordance with a fourth aspect of the invention, a method for reinforcing a structure capable of forming fibers from a fluid material supplied to a bushing is disclosed. The method comprises securing at least one reinforcement member to the structure, said reinforcement member comprising a first portion for attachment to the structure and a second portion having a profile with a variable height including at least one apex. The variable height of the reinforcement member including the at least one apex enhances the resistance of the structure to bending stresses and extends the service life thereof while minimizing the amount of precious metal used for reinforcement. In one embodiment, the securing step comprises securing a plurality of independent reinforcement members to the structure in a spaced relationship. The reinforcement member may comprise a first member defining the first portion and a second member defining the second portion, in which case the securing step comprises securing the first member to the structure, and securing the second member to the first member. The fiber forming structure may further comprise a tip plate including at least one existing gusset, in which case said method further includes attaching the second portion of the reinforcement member to the gusset. The reinforcement member second portion thus assists in preventing both the gusset and the tip plate from sagging as the result of bending stresses and creep. In accordance with a fifth aspect of the invention, a reinforcement member for use in a bushing assembly for forming fibers from a fluid material at an elevated temperature is provided. The bushing assembly includes a bushing tip plate having an upper surface and a plurality of strategically positioned fiber-forming orifices. The reinforcement member comprises a body having a lower portion including a web for attachment to the upper surface of the bushing tip plate and an upper portion integrally formed with the lower portion. The upper portion has a profile shaped for resisting both a bending stress created partially by the weight of the material and a creep created partially by the elevated temperature of the material over time in combination with the bending stress, and including at least one apex. The variable height profile of the body including at least one apex enhances the resistance of the bushing tip plate to sagging and thereby substantially extends the service life thereof while rninirnizing the amount of precious metal used for reinforcement. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 schematically illustrates one example of a prior art arrangement for reinforcing a tip plate for forming fibers from a fluid material at an elevated temperature, such as glass, by using a plurality of T-shaped gussets having a substantially planar upper surface that creates a rectangular profile; Fig. 2 demonstrates the manner in which the T-shaped gussets of Fig. 1 bend or sag over time, primarily as the result of the creep induced by the bending stresses created by the prolonged contact with glass at an elevated temperature during the fiber-forming process; Fig. 3a is a perspective view showing a pair of improved reinforcement members, including a first portion for attachment to the tip plate and a second, upper portion including a profile having a variable height with an apex located at the midpoint between the sidewalls, wherein the reinforcement member reduces the incidence of creep-induced sag and extends the service life of the tip plate; Fig. 3b is a perspective view showing an alternate embodiment of a pair of improved reinforcement members for reducing the incidence of creep-induced sag and extending the service life of the tip plate, with the apex being located at a point other than the midpoint taken along the length of the body of the reinforcement member; Fig. 4a is a partially cutaway, partially cross-sectional, elevational view taken from one end of the reinforcement members of either Fig. 3a or Fig. 3b; Fig. 4b is a partially cutaway, fully cross-sectional view of the reinforcement member of Fig. 4a, taken at the apex thereof; Fig. 5a is an embodiment of a reinforcement member formed of at least one piece of material, and further including a plurality of strategically positioned openings for reducing the amount of material used in forming the reinforcement member without significantly compromising the strength thereof; Fig. 5b is a view taken along view line 5b-5b; Fig. 6a is a partially cutaway, partially cross-sectional end elevational view of an embodiment wherein the reinforcement member includes a lower portion having an L- shaped cross-section; Fig. 6b is a partially cutaway, fully cross-sectional view of an embodiment wherein the reinforcement member comprises separate first and second members secured together, such as by welding, with each member having an L-shaped cross-section; Fig. 7a is a partially cutaway, fully cross-sectional end view of an embodiment wherein the reinforcement member includes a body having a first or lower portion that is T-shaped in cross-section and a second or upper portion having a variable height including an apex, with the body being fabricated from a single piece of material, such as by stamping, forging, or the like; Fig. 7b is a partially cutaway, fully cross-sectional end view of an embodiment wherein the reinforcement member includes a body having an L-shaped cross-section and having a variable height including an apex, with the body being fabricated from a single piece of material, such as by stamping, forging, or the like; Fig. 8 is a partially cutaway, side elevational view of a portion of a bushing body including a tip plate with a reinforcement member comprising a body with an arcuate profile having a variable height and a single apex; Fig. 9 is a view similar to Fig. 8, but with the second portion of the body of the reinforcement member having a height that increases substantially linearly from each end thereof to create an inverted V-shaped profile; and Fig. 10 is a view similar to Figs. 8 and 9, but with the second portion of the body of the reinforcement member including two apexes to create an inverted W-shaped profile for a two tip plate bushing. DETAILS DESCRIPTION AND PREFERRED EMBODIMENTS OF THE INVENTION Reference is first made to Fig. 1, which is a schematic illustration of a portion of a prior art fiber-forming structure wherein a plurality of gussets G1, G2 are attached to the upper surface Su of a tip plate T (shown in phantom). The tip plate T is formed from platinum, alloys thereof or a like material, and includes between about 10 and 100 small tips or orifices O through which molten material, such as glass, passes (see, for example, Figs. 4a and 4b). The molten material contacts the upper surface Su of the tip plate T prior to it passing through the orifices O to be drawn into fibers. The gussets G1, G2 are formed from platinum, alloys thereof, or a like material. As is known in the art, electric current is typically supplied to the tip plate T from a power source, such as a transformer, to create resistive heating. This heating helps to maintain the glass or other material in a molten state as it passes through the orifices O or tips in the plate T. As noted above, a more detailed description of the overall process is found in the commonly assigned Bobba '727 and Carey '430 patents incorporated herein by reference. The tip plate T is supported in a bushing body (not shown) having sidewalk and end walls. Together, the side and end walls serve as a frame for supporting or carrying the tip plate T. Over time, the bending stresses created by gravity, fiber tension and the weight of the molten glass and the concomitant elevated temperature cause the tip plate T to sag, primarily in the "middle" portion (that is, the portion located farthest away from the side and end walls of the corresponding bushing body). It is well known that this sagging reduces the effectiveness of the tip plate T, since it results in a non-uniform thermal distribution and, hence, the creation of fibers of non-uniform diameters due to uneven heat transfer to the cooling fins. Production of fibers of non-uniform diameters is undesirable, and is usually the primary factor that necessitates retiring the tip plate T from service and replacing it with a new or reconditioned one. While the T-shaped gussets G1, G2 are initially capable of resisting the bending stresses, creep causes a time dependent strain that produces a deflection. As the T-shaped gussets Gl, G2 are simple prismatic beams, that is, constant cross section, the maximum deflection must occur at the span midpoint under uniform loading. Hence, as shown in Fig. 2, the gussets G1, G2 eventually bend or sag along with the tip plate T (note reference numeral S designating the sagging in the vertical dimension shown for purposes of illustration). In an effort to combat this sagging, the present invention includes an improved reinforcement member 10, which may either be used in place of the conventional gusset(s) or may be formed by securing or attaching a separate strengthening member to a conventional gusset(s). Figs. 3a and 3b each illustrate a tip plate T in phantom including a plurality of spaced reinforcement members 10a, 10b falling into the latter category, and constructed in accordance with one possible embodiment of the present invention. While only two reinforcement members 10a, 10b are shown, it should be appreciated that more or fewer may be provided, depending on the dimensions of the tip plate T and other aspects of the particular application. Specifically, as perhaps best shown by viewing Figs. 4a and 4b together with Fig. 3a, each of the plurality of reinforcement members 10a, 10b includes a body having a first, lower portion 12. As should be appreciated from the foregoing discussion, this portion 12 may comprise a conventional gusset already coupled to the tip plate T, or may form part (that is, the lower portion) of an uncoupled, complete reinforcement member 10 which is intended to be secured directly to the planar upper surface of a tip plate T at various strategic locations. The lower portion 12 in the illustrated embodiment has a T-shaped cross-section, including: (1) a relatively thin web 14 having a lower end, along which the weld W or other bond, such as a mechanical joint, securing the reinforcement member 10a or 10b to the tip plate T between adjacent rows of orifices O is formed; and (2) a transverse member 16 at the opposite end of the web 14 creating a substantially planar upper surface and defining at least one, and preferably a pair of opposed flanges 18a, 18b. Alternatively, the lower portion 12 may be formed from a single piece of T-shaped material fabricated using stamping, extruding, forging, or other techniques, but this may increase the expense. At the present time, the less expensive, and thus, preferred manner of forming the reinforcement member 10a or 10b is by securing the transverse member 16 directly to the web 14, such as by laser or TIG welding (note welds W in the embodiment shown in Figs. 4a and 4b). The lower portion 12 is preferably formed from platinum, alloys thereof or a like material. The reinforcement members 10a, 10b further include an upper portion 20, also having a T-shaped cross-section including a web 22 and a transverse member 24. This transverse member 24 thus creates at least one, and preferably a pair of opposed flanges 26a, 26b that define an upper surface US (see Fig. 4a). As with the lower portion 12, these flanges 26a, 26b may be created using a separate piece of material welded or otherwise bonded to the upper end of the web 22. However, the use of a single piece of material to form the upper portion 20 is also possible, such as one constructed using known stamping, or forging techniques. In this particular embodiment, and as perhaps best shown in Fig. 4a, the lower end of the web 22 of the upper portion 20 may be attached to the upper surface of the transverse member 16 of the lower portion 12, such as by welding or any other means for forming a secure, permanent or semi-permanent bond. The upper portion 20 preferably is formed from the same material used to form the lower portion 12, which materials are set out above. The upper portion 20 of each reinforcement member 10a or 10b includes a profile with a variable height that forms at least one apex A. Thus, in the embodiment of Fig. 3a, the slope or height of the upper end 22a of the web 22 increases linearly from each end of the reinforcement member 10a or 10b, such that the apex A is positioned substantially at the midpoint M along the length thereof (which may also coincide with the midpoint between the sidewalls of the bushing body (not shown, but see, for example, Figs. 8-10)). Further, the web 22, in the illustrated embodiment, has triangular-shaped side portions 22b and 22c, see Figs. 3a and 4b. The transverse member 24 (or members) also assist in defining this profile. The end result of this arrangement is that, in terms of susceptibility to bending stress and creep, the maximum or peak resistance to bending is theoretically provided at the midpoint M, which is the precise location where the sagging is typically the greatest. Also, in this particular embodiment, the added weight is kept to a rninimum while still providing the desired degree of reinforcement by providing the upper portion 20 with a T- shaped cross-section, as opposed to simply using a solid block of material. By also forming each reinforcement member 10a or 10b from separate pieces of material sequentially welded together, the overall cost required for implementing this arrangement may be minimized. This mode of construction may also allow for the reinforcement members 10a or 10b to be easily retrofitted onto tip plates T already in service having existing gusset(s) (in which case only the upper portion 20 of the embodiment shown in Figs. 3a, 4a, and 4b need be provided). In the embodiment of Fig. 3b, the profile of the upper portion 20, including the transverse members) 24, varies in height and includes at least one apex A. However, the web 22 is asymmetrical, with each side having a different slope. As a result, the apex A does not fell at the midpoint M (note dashed vertical lines) between the ends of the lower portion 12 of the reinforcement member 10a, 10b (or the sidewalls of the bushing body, in the case where the ends of the lower portion 12 of the reinforcement member are coextensive therewith). This arrangement or any variation thereof may be useful in special situations where the location of the maximum bending stress across the tip plate T is not necessarily at the midpoint M or other design criteria preclude placing the apex at the midpoint. In these situations, the approximate location for placing the apex A may be determined empirically or predicted using well-known analytical or other modeling techniques, such as finite element analysis. Fig. 5a is a side elevational view and Fig. 5b is a cross-sectional view of another embodiment of a reinforcement member 110. In this embodiment, the lower and upper portions 112,120 are defined by a single piece of material having a T-shaped cross- section, but may be defined by two separate pieces of material. More specifically, the lower portion 112 is defined by a lower portion 114a of a single, vertically oriented web 114. The lowermost end of this web 114 is attached to the surface of the tip plate T, such as by welding, between adjacent rows of orifices O extending along the width thereof. The upper portion 120 of the reinforcement member 110 includes an upper portion 114b of the web 114, as well as at least one transverse member 124 attached to the upper end thereof. The transverse member 124 defines at least one, and preferably a pair of opposed flanges 126a, 126b. As with the embodiments described above, the flanges 126a, 126b may instead be separately attached, such as by welding or other permanent or semi- permanent bonding (see Fig. 5a). The upper portion 120 of the reinforcement member 110, including the transverse members) 124 and the upper web portion 114b, also has a variable height when viewed in profile to define at least one apex A. As with the embodiment in Fig. 3a, the apex A is shown as being located substantially at the midpoint M between the ends of the reinforcement member 110. By positioning the apex A at this location, which is typically where the maximum bending stress is created, the ability of the corresponding portion of the tip plate T to resist sagging is greatly enhanced, which in turn extends the service life. As noted above, it should be appreciated that the embodiment shown in Fig. 5a could also be constructed such that the apex A (or multiple apexes; see, for example, Fig. 10) does not coincide with the midpoint M. This arrangement may be useful in cases where the maximum stress or bending might not be at the midpoint M or other design criteria precludes placing the apex at the span midpoint. Fig. 5a also demonstrates one manner in which apertures or openings 130 may also be provided in the reinforcement member 110, such as in the web 124. These apertures or openings 130 reduce the overall amount of material required during fabrication, and thus reduce the cost and weight contribution of each reinforcement member 110. However, the openings 130 are sized and strategically positioned such that no significant reduction in the resistance to bending stresses or sagging results. In the example shown, three such openings 130 are provided, but fewer or more may be provided. Also, while circular openings 130 are shown for purposes of illustration, it should be appreciated that any shape may be used, as long as the result is that the reinforcement in strength provided to the tip plate T remains uncompromised. Moreover, while the openings 130 are shown in the embodiment of Fig. 5a, it should be appreciated that any of the other embodiments may benefit from their presence, either in the upper portion (see, for example, Fig. 9), the lower portion (not shown), or in both portions of the reinforcement member (not shown). It is believed that the reinforcement member 110 illustrated in Fig. 5a provides optimal strength with minimal metal weight. Another embodiment is depicted in the partially cutaway, partially cross-sectional, end elevational view of Fig. 6a. In this embodiment, the reinforcement member 210 has a lower portion 212 having a cross-section in the shape of an inverted "L." The lower end of the web 214 of the "L" is secured to the surface of the tip plate T between adjacent rows of orifices, such as by welding (note welds W). The upper portion 220 of the reinforcement member 210 is also L-shaped in cross-section, as perhaps best understood with reference to the cross-sectional view of Fig. 6b. Thus, it too includes a web 222 that is secured to the transverse member 216 of the lower portion 212, such as by welding, to provide the resulting reinforcement member 210 with an F-shaped cross-section. This reinforcement member 210 is thus integrally formed with the tip plate T by welding the I-shaped member forming the lower portion 212 to the tip plate T, either before or after the L- shaped member forming the upper portion 220 has been welded to the lower portion 212. However, as noted above, it is of course possible, but more expensive, to create the entire reinforcement member 210 from a single piece of material having an F-shaped cross- section that is then welded directly to the tip plate T. Although not specifically illustrated, it should also be appreciated that to reduce the effects of sagging and extend the service life of the tip plate T, the upper portion 220 of the reinforcement member 210 has a variable height when viewed in profile, and thus defines at least one apex A. Indeed, in an embodiment of reinforcement member 210 where the height increases linearly from the sides to the midpoint, the actual side elevational view from the right side of Fig. 6b would be identical to one taken looking from the left or right side of Fig. 3a, with the observer's eye at or near the horizontal plane defined by the tip plate T. The view from the opposite, or left hand side of Fig. 6b would be similar to the view in Fig. 5a, but without the flange 126a or 126b shown along the top of the reinforcement member and with a partial or full length bead present where the web 222 of the upper portion 220 is welded directly to the upper surface of the transverse member 216 of the lower portion 212. Still another possible embodiment is shown in Fig. 7a. In this embodiment, the entire reinforcement member 310, including the lower and upper portions 312, 320, is fabricated from a single piece of material, similar to one version of the embodiment shown in Fig. 5a. However, in addition to flanges 326a, 326b, the member 310 also includes integral flanges 318a, 318b that add strengm and further help in resisting sagging. While this embodiment uses more material and is thus slightly heavier than the one shown in Fig. Sa (and also costs more to manufacture using current stamping or forging techniques), it reduces the amount of welding required as compared to the embodiment of Fig. 3 a, since welds are required only at the interface between the lower end of the web 314 and the surface of the tip plate T. Also, it may find utility in situations where the tip plate T is exceedingly wide, or others where a more substantial reinforcement is required. A similar embodiment of a reinforcement member 310 formed of a single piece of material having an L-shaped cross-section is shown in Fig. 7b. This reinforcement member 310 also has a variable height profile with an apex (not shown). When viewed from the right hand side of Fig. 7b, the view is similar to that of Fig. 5a (possibly without the optional openings 130). Up to this point, the reinforcement members 10,110,210,310 have been shown and described for use on a single, substantially planar tip plate T that extends between a pair of sidewalls in a bushing body (not shown). However, it is also possible to use the reinforcement members 10,110,210,310 in situations where a "double-bottomed" bushing is provided. This is illustrated in Figs. 8-10, with only one half of each "double- bottomed" bushing shown in Figs. 8 and 9 (note centerline L), and a full "double- bottomed" bushing shown in Fig. 10. In the first embodiment, the reinforcement member 410 has an upper portion 420 similar to the others described above. The difference is that instead of an apex A formed by linearly increasing the height from the spaced ends, the height is varied non-linearly from each side so as to create an arcuate profile. Preferably, as with the other embodiments, the apex A is located substantially at the midpoint M between the ends of the reinforcement member 410 to provide the optimum resistance to bending stresses, and hence, time-induced plastic deformation (creep). In this embodiment, the apex A does not coincide with the midpoint between the sidewalls (only one sidewall S1 is shown in Fig. 8), which may fall at or near the centerline L. It should also be appreciated that the embodiment of Fig. 8 may be formed like the one in Fig. 3a, with the upper portion 420 having the arcuate profile separately welded or attached to an upper surface defined by a transverse member 416 creating opposed flanges 418a or 418b (only one shown in Fig. 8). The lower portion 412 is in turn secured to the surface of the tip plate T between adjacent rows of orifices O, and could possibly take the form of an existing gusset G, with the upper portion 420 merely serving as an add-on strengthening or reinforcement member. Both the end elevational and cross-sectional views of this embodiment are substantially the same as those in Figs. 4a and 4b, but could also be like those in Figs. 6a and 6b as well Alternatively, the reinforcement member 410 with the upper portion 420 having the arcuate profile may be fabricated from a single piece of material. Still another alternative is to form the upstanding portion or web 422 from a single piece of material, and then separately attach the curved transverse member 424, such as by welding. In any of these cases, both the upper and lower portions 412,420 may have T-shaped or L-shaped cross- sections (with both preferably having the same cross-sectional shape). Also, although not shown in Fig. 8, it should be appreciated that either portion may include weight-reducing apertures or openings. Still referencing Fig. 8, it is further noted that in the illustrated embodiment, the upper portion 420 stops short of the sidewall S1 as does the transverse member 416 defining the flanges 418a or 418b (only one shown). The clearance thus created allows for the welder to gain access to the sidewall S1 so that a weld may be laid along the corresponding end of the web 414. This clearance is particularly helpful in the case where a plurality of closely spaced reinforcement members are provided (not shown). The embodiment shown in Fig. 9 includes a combination of features taken from the embodiments of Figs. 3a-4b, 5a, and 9. The upper portion 520 of the reinforcement member 510 has an inverted, V-shaped profile with an apex A, and is formed from a separate piece of material that is welded or otherwise secured to the transverse member 516 of the lower portion 512 (both of which may have a T-shaped or L-shaped cross- section). A plurality of relatively small, strategically positioned openings 530 are also provided in the upper portion 520, which as noted above decrease the weight of the resulting reinforcement member 510 without substantially compromising the strength. The upper portion 520 also creates a gap with the sidewall S1. As noted in the previous paragraph, this is optionally done to provide access to the interface between the end of the lower portion 512 and the sidewall S1. In the embodiment shown in Fig. 10, the first noteworthy point is that the full "double bottom" bushing B or bushing assembly is shown in cross-section, including the spaced sidewalls S1, S2 and the tip plate(s) T. In the illustrated embodiment, the tip plates T are integrally connected with an inverted V-shaped channel C. This channel C extends along the length of the bushing B to provide enhanced structural support, and may be filled with a refractory material R to insulate against heat losses to a water cooled support (not shown). As is known in the art, the refractory material R usually also surrounds the entire bushing B to not only thermally insulate it from the ambient environment, but also electrically insulate it from other structures. Secured to the surface of each tip plate T is a reinforcement member 610. The reinforcement member 610 includes a lower portion 612, which as noted above may be formed by the gussets having a T-shaped or L-shaped cross-section already present on the tip plate T. The upper portion 620 in this embodiment has a profile that varies in height to define two apexes A1, A2, one positioned substantially at the midpoint of each tip plate T. Thus, the profile of the upper portion 620 has the shape of an inverted W. The upper portion 620 may be formed of a single piece of material, including a continuous web 622, or may have one or more transverse members 624 (two shown in Fig. 10) that are separately welded in place. Alternatively, both the lower and upper portions 612,620 may be formed from a single piece of material, along with the transverse member 624 defining at least one, and preferably a pair of opposed flanges. The upper portion 620 is also shown as having ends that are spaced from the sidewalls S1, S2 to permit access during welding, but as described above, this is optional. The foregoing descriptions of embodiments of the present invention are presented for purposes of illustration and description. These descriptions are not intended to be exhaustive or to limit the invention to the precise form disclosed. Obvious modifications or variations are possible in light of the above teachings. For example, while only a single reinforcement member or pair of reinforcement members are shown in the various drawings, it should be appreciated that any number required to provide the desired degree of reinforcement/resistance may be used at any spaced interval along the tip plate. Also, the reinforcement members, whether formed from a single piece of material, multiple pieces of material, or as add-ons to existing gussets, may be placed only at locations susceptible to the maximum bending stresses, with other locations either having the conventional gussets or no reinforcement Infinite variations on the shapes of the profiles or cross-sectional shapes of the various reinforcement members or components thereof may also be made, while still possibly achieving an acceptable level of reinforcement/resistance. For example, while T-shaped, F-shaped, and inverted L-shaped cross-sections create a minimal point of contact with the tip plate and minimize the added weight, the reinforcement member could have a C-shaped, I-shaped, or E-shaped cross- section as well, or any variation thereof. The embodiments described were chosen to provide the best illustration of the principles of the invention and its practical application to thereby enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. All such modifications and variations are within the scope of the invention as determined by the appended claims when interpreted in accordance with the breadth to which they are fairly, legally and equitably entitled. WE CLAIM 1. In a bushing assembly having a plate like structure comprising a plurality of orifices for forming fibers from a fluid material, a member (10a, 10b) for reinforcing the structure comprising:- • a steel structure body having a first portion (12) having a profile with variable height comprising at least one Apex (A); • whereby the variable height profile and the at least one apex of the body assists in reinforcing, "characterized in that the said structure resists sagging, increases service life, minimizes the amount of precious metal usage for reinforcement, enhances the resistance of the structure from bending stress and creep. 2. The reinforcement, member as claimed in claim 1, wherein the body is comprised of a single piece of material. 3. The reinforcement member as claimed in claim 2, wherein the body comprising the first and second portions has an inverted L-shaped (310), T-shaped (312, 320), or F-shaped cross-section (210). 4. The reinforcement member as clamed in claim 3, wherein the second portion of the body has an arcuate profile (420), an inverted V-shaped profile (520), or an inverted W-shaped profile (620). 5. The reinforcement member as claimed in claim 1, wherein the body has a length including a midpoint (M), and wherein the at least one apex (A) is located substantially at the midpoint. 6. The reinforcement member as claimed in claim 1, wherein the bushing assembly have spaced sidewalls (S1, S2) to which a first and second end of the body are secured, respectively, and wherein the at least one apex is located between the spaced sidewalls. 7. The reinforcement member as claimed in claim 1, wherein the bod/ comprises: a first member defining the first portion for attachment to the structure; and a second member coupled with the first member, defining the second portion and having the variable height profile with the at least one apex. 8. The reinforcement member as claimed in claim 7, wherein the first member has a T-shape (12) or an inverted L-shaped (212) in cross- section. 9. The reinforcement member as claimed in claim 7, wherein the second member has a T-shaped (20) or an inverted L-shaped (220) in cross- section and is formed from one or more component parts. 10.The reinforcement member as claimed in claim 7, wherein the second portion has an arcuate profile, an inverted V-shaped profile, or an inverted W-shaped profile. 11.The reinforcement member as claimed in claim 7, wherein the second member provides a web (22) having an end that is welded directly to an upper surface of the first member. 12.The reinforcement member as claimed in claim l, wherein the second portion of the body comprises at least two apexes (A1, A2). 13.The reinforcement member as claimed in claim 1, wherein either the first (112) or the second portion (120) of the body includes a plurality of strategically positioned openings, whereby the openings (130) serve to reduce the amount of material required to fabricate the reinforcement member without compromising the strength thereof. 14.A bushing assembly for use in forming a plurality of fibers from a fluid material at an elevated temperature comprising: a structure having a plurality of orifices through which the fluid material passes to form the fibers; at least one reinforcement member (10a, 10b) having a first portion (12) for attachment to the structure (T) and a second portion (20) having a profile with a variable height having at least one apex (A), whereby the variable height of the reinforcement member comprising the at least one apex enhances the resistance of the structure to sagging and extends the service life thereof while minimizing metal usage. 15.The brushing assembly as claimed in claim 14, wherein the fiber forming structure is plate-like, and wherein the at least one reinforcement member extends along a width dimension thereof. 16.The brushing assembly as claimed in claim 15, wherein a plurality of independent, spaced reinforcement members extending along the width of the plate-like structure. 17.The brushing assembly as claimed in claim 16, wherein the fiber-forming structure has an upper surface to which the first portion of each of the reinforcement members is welded. 18.The brushing assembly as claimed in claim 14, wherein the reinforcement member is fabricated from either a single piece of material or at least two pieces of material secured together. 19.The brushig assembly as claimed in claim 14, wherein the structure provides at least one existing gusset (GO, and wherein the second portion of the reinforcement member is attached to the gusset. 20. A method for reinforcement a plate or plate-like structure for forming fibers from a fluid material supplied to a brushing, comprising: securing at least one reinforcement member (10a, 10b) to the fiber- forming structure, said reinforcement member comprising a first portion (12) for attachment to the structure (T) and a second portion (20) having a profile with a variable height having at least one apex (A), whereby the variable height of the reinforcement member having the at least one apex enhances the resistance of the structure to bending stresses and extends the service life thereof while minimizing metal usage. 21.The method as claimed in claim 20, wherein the securing step comprises securing a plurality of independent reinforcement members to the fiber- forming structure in a spaced relationship. 22.The method as claimed in claim 20, wherein the reinforcement member comprises a first member providing the first portion and a second member providing the second portion, and wherein the securing step comprises securing the first member to the fiber forming structure, and securing the second member to the first member. 23.The method as claimed in claim 20, wherein the fiber forming structure comprises at least one existing gusset (G1), and said method further includes attaching the first portion of the reinforcement member to the gusset. 24.In a bushing assembly for forming fibers from a fluid material at an elevated temperature using a bushing tip plate (T) having an upper 21 surface and a plurality of strategically positioned fiber-forming orifices, a reinforcement member (10a, 10b), comprising: a body having a lower-portion (12) and a web (22) for attachment to the upper surface (20) of the bushing tip plate and an upper portion coupled with the lower portion, said upper portion having a variable height profile shaped for resisting both a bending stress created partially by the weight of the material and a creep created partially by the elevated temperature of the material over time in combination with the bending stress, said profile including at least one apex (A), whereby the profile of the bode,Including the at least one apex enhances the resistance of the bushing tip plate to sagging and thereby substantially extends the service life thereof while minimizing metal usage. In a bushing assembly having a plate like structure comprising a plurality of orifices for forming fibers from a fluid mater, a number (10a, 10b) for reinforcing the structure comprising:- A T-shaped structural body having a first portion (12) having a profile with variable height comprising a least one Apex (A); whereby the variable profile and the atleast one apex of the body assists in reinforcing the structure against sagging and extends the service life thereof while minimizing metal usage.

Full Text

REINFORCEMENT MEMBER FOR A BUSHING TIP PLATE AND METHOD OF REINFORCING THE
PLATE
TECHNICAL FIELD AND INDUSTRIAL
APPLICABILITY OF THE INVENTION
The present invention relates generally to bushings for forming fibers from a fluid
material, such as glass at an elevated temperature and more particularly, to an improved
manner of reinforcing a bushing tip plate to extend the service life thereof.
BACKGROUND OF THE INVENTION
Various types of bushings or bushing assemblies for forming fibers or filaments
from a fluid material, such as glass at an elevated temperature, are known in the art.
Usually, the bushing or bushing assembly includes a rectangular bushing body having
sidewalls and end walls. Together, the side and end walls serve as a frame for supporting
or carrying one or more, often elongated plate-like structures, typically formed of platinum
or alloys thereof, having a plurality of small orifices or "tips." These tips receive the
molten material as it passes through the bushing body from an upstream source, such as a
forehearth. To assist in keeping the material in a molten state as it enters and passes
through these tips, the plates are heated, usually by electrically coupling them to a source
of high current, such as a transformer. As molten glass material streams exit the tips, they
are mechanically drawn to form continuous fibers which are wound onto mandrels or
creels or directly chopped for later processing or use. A detailed description of the basic
apparatus and methodology used is found in commonly assigned U.S. Patent Nos.
5,709,727 to Bobba and 3,920,430 to Carey, the disclosures of which are incorporated
herein by reference.
To improve the output and efficiency of the overall fiber-forming operation, it is of
course desirable to maximize the number of fibers created by the tip plate. To do so, a tip
plate can in theory be made infinitely large in both the width and length dimensions.
However, several well-recognized problems arise, especially when the width dimension of
a tip plate is significantly increased relative to the length dimension.
Perhaps the most prevalent problem resulting from increasing the dimensions of
the tip plate, and in particular, the width dimension, to the degree necessary to realize a
significant increase in fiber output is a sharp reduction in the service life. The tip plate is
normally rectangular in top plan view, with its four side edges welded directly to the
opposed side and end walls of the rectangular bushing body. When the width dimension
of the tip plate increases relative to the length dimension, the plate essentially acts as a
simple beam supported at the sides and ends, with no direct support at the "middle" (that
is, the portion furthest from the side and end walls of the corresponding bushing body).
Significant bending stresses acting on the tip plate as the result of prolonged contact with
the heavy molten material over time results in sagging due to time dependent plastic
deformation, or creep. This sagging is deleterious primarily because it results in non-
uniform thermal distribution and the concomitant production of fibers having substantially
different diameters across the tip plate. That is, the extremes in temperature cause some
bushing tips to become too cold to attenuate a fiber and others are hot enough to cause a
forming instability. Both cases cause fiber breakage and a loss in conversion efficiency.
Reducing the width dimension of the plate is therefore desirable to curtail the
effects of creep and increase the service life. However, the trade-off is an undesirable
reduction in output and a concomitant increase in cost when only a single narrow-width tip
plate is used. Also, after prolonged use, even a single narrow-width tip plate eventually
suffers from creep-induced sagging, non-uniform fiber output, and increased fiber break
rates.
In an effort to increase the service life of a bushing tip plate to overcome this
problem and others, the present Assignee has in the past employed reinforcing members
formed of platinum or a platinum alloy, termed "gussets." These gussets usually extend
width-wise across the upper surface of the tip plate (that is, between the sidewalls of the
bushing body) at spaced intervals, and typically have a cross-section that corresponds in
shape to a "T" or inverted "L." In use, me depending "leg" formed by the web of each
gusset is secured directly to the upper surface of the tip plate, such as by laser or tungsten-
inert gas (TIG) welding.
While these gussets do serve to extend the service life of the tip plate, including
even in the narrow-width case, the degree of the benefit gained is somewhat limited. In
particular, the gussets having a T-shaped or inverted L-shaped cross-section are also
susceptible to sagging due to bending stresses and creep as the underlying tip plate. This is
because the gusset, while providing some reinforcement strength, also behaves like a
simple beam, and thus experiences maximum deflection at the span midpoint as in an
unsupported tip plate. In other words, despite the reinforcement, the maximum or peak
stress and hence, the maximum or peak sag, still occurs at the middle of the tip plate away
from the side and end walls. Accordingly, a need for an improved manner of reinforcing
tip plates, including those existing bushing designs (with or without gussets) with an eye
toward further extending their service life is identified.
SUMMARY OF THE INVENTION
In accordance with a first aspect of the invention, a reinforcement member for a
bushing assembly having a plate-like structure including a plurality of orifices for forming
fibers from a fluid material is provided. The member comprises a body including a first
portion for attachment to the structure and a second portion having a profile with a
variable height including at least one apex. The variable height profile and the at least one
apex of the body assists in reinforcing the plate-like structure against sagging and extends
the service life thereof without undue alloy usage.
In one embodiment, the reinforcement member is comprised of a single piece of
material, with the body including the first and second portions having an inverted L-
shaped, T-shaped, or F-shaped cross-section. The profile of the second portion of the body
may have an inverted V-shaped, inverted W-shaped, or arcuate profile. Preferably, the
body has a length including a midpoint, with the at least one apex located substantially at
the midpoint. The midpoint may also be the midpoint between the spaced sidewalls or
external support points of the bushing assembly to which a first and a second end of the
body are secured.
In other embodiments, the body comprises a first member defining the first portion
for attachment to the structure and a second member coupled with the first member,
defining the second portion and having the variable height profile with the at least one
apex. The first member may have a T-shape or an inverted L-shape in cross-section.
Likewise, the second member may have a T-shape or an inverted L-shape in cross-section,
and may be formed from one or more component parts. Additionally, the second portion
may have an arcuate profile, an inverted V-shaped profile, or an inverted W-shaped
profile, each including the at least one apex. Preferably, the second member includes a
web having an end that is welded directly to an upper surface of the first member, and
optionally may have a profile that defines two or more apexes. In any of the embodiments,
either the first or second portion of the body may include a plurality of strategically
positioned openings. These openings serve to reduce the amount of material required to
fabricate the reinforcement member without compromising the strength thereof.
In accordance with a second aspect of the invention, a bushing assembly for use of
forming a plurality of fibers from a fluid material at an elevated temperature is disclosed.
The assembly comprises a structure having a plurality of orifices through which the fluid
material passes to form the fibers and at least one reinforcement member. This member
comprises a first portion for attachment to the structure and a second portion having a
profile with a variable height including at least one apex. The variable height of the
reinforcement member including the at least one apex enhances the ability of the structure
to resist sagging and extends the service life thereof while minimizing the amount of
precious metal used for reinforcement
The fiber forming structure is typically plate-like, with different width and length
dimensions to form a rectangular shape. In one embodiment, at least one reinforcement
member extends along a width dimension of the plate, and preferably a plurality of
independent, spaced reinforcement members extend width-wise along the plate-like
structure. The fiber-forming structure also has an upper surface (the molten glass material
contacts this surface) to which the first portion of each reinforcement member may be
welded. Each reinforcement member maybe fabricated from either a single piece of
material or at least two pieces of material secured together, such as by welding.
In accordance with a third aspect of the invention, a reinforcement member portion
for use in a bushing assembly having a fiber-forming tip plate including at least one
existing gusset is provided. The reinforcement member portion comprises a body for
attachment to the gusset and having a profile with a variable height including at least one
apex. The variable height and the at least one apex of the reinforcement member portion
assists in reinforcing the gusset and hence, at least the adjacent portion of the tip plate,
against sagging, which extends the service life thereof while minimizing the amount of
precious metal used for reinforcement.
In one embodiment, the gusset has a substantially planar upper surface and the
body of the reinforcement member portion includes a web having a first end that is welded
to the upper surface of the gusset. The body may have a T-shaped or inverted L-shaped
cross section, and the profile of the body may be selected from an arcuate profile, an
inverted V-shaped profile, or an inverted W-shaped profile.
In accordance with a fourth aspect of the invention, a method for reinforcing a
structure capable of forming fibers from a fluid material supplied to a bushing is disclosed.
The method comprises securing at least one reinforcement member to the structure, said
reinforcement member comprising a first portion for attachment to the structure and a
second portion having a profile with a variable height including at least one apex. The
variable height of the reinforcement member including the at least one apex enhances the
resistance of the structure to bending stresses and extends the service life thereof while
minimizing the amount of precious metal used for reinforcement.
In one embodiment, the securing step comprises securing a plurality of independent
reinforcement members to the structure in a spaced relationship. The reinforcement
member may comprise a first member defining the first portion and a second member
defining the second portion, in which case the securing step comprises securing the first
member to the structure, and securing the second member to the first member. The fiber
forming structure may further comprise a tip plate including at least one existing gusset, in
which case said method further includes attaching the second portion of the reinforcement
member to the gusset. The reinforcement member second portion thus assists in
preventing both the gusset and the tip plate from sagging as the result of bending stresses
and creep.
In accordance with a fifth aspect of the invention, a reinforcement member for use
in a bushing assembly for forming fibers from a fluid material at an elevated temperature is
provided. The bushing assembly includes a bushing tip plate having an upper surface and
a plurality of strategically positioned fiber-forming orifices. The reinforcement member
comprises a body having a lower portion including a web for attachment to the upper
surface of the bushing tip plate and an upper portion integrally formed with the lower
portion. The upper portion has a profile shaped for resisting both a bending stress created
partially by the weight of the material and a creep created partially by the elevated
temperature of the material over time in combination with the bending stress, and
including at least one apex. The variable height profile of the body including at least one
apex enhances the resistance of the bushing tip plate to sagging and thereby substantially
extends the service life thereof while rninirnizing the amount of precious metal used for
reinforcement.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 schematically illustrates one example of a prior art arrangement for
reinforcing a tip plate for forming fibers from a fluid material at an elevated temperature,
such as glass, by using a plurality of T-shaped gussets having a substantially planar upper
surface that creates a rectangular profile;
Fig. 2 demonstrates the manner in which the T-shaped gussets of Fig. 1 bend or sag
over time, primarily as the result of the creep induced by the bending stresses created by
the prolonged contact with glass at an elevated temperature during the fiber-forming
process;
Fig. 3a is a perspective view showing a pair of improved reinforcement members,
including a first portion for attachment to the tip plate and a second, upper portion
including a profile having a variable height with an apex located at the midpoint between
the sidewalls, wherein the reinforcement member reduces the incidence of creep-induced
sag and extends the service life of the tip plate;
Fig. 3b is a perspective view showing an alternate embodiment of a pair of
improved reinforcement members for reducing the incidence of creep-induced sag and
extending the service life of the tip plate, with the apex being located at a point other than
the midpoint taken along the length of the body of the reinforcement member;
Fig. 4a is a partially cutaway, partially cross-sectional, elevational view taken from
one end of the reinforcement members of either Fig. 3a or Fig. 3b;
Fig. 4b is a partially cutaway, fully cross-sectional view of the reinforcement
member of Fig. 4a, taken at the apex thereof;
Fig. 5a is an embodiment of a reinforcement member formed of at least one piece
of material, and further including a plurality of strategically positioned openings for
reducing the amount of material used in forming the reinforcement member without
significantly compromising the strength thereof;
Fig. 5b is a view taken along view line 5b-5b;
Fig. 6a is a partially cutaway, partially cross-sectional end elevational view of an
embodiment wherein the reinforcement member includes a lower portion having an L-
shaped cross-section;
Fig. 6b is a partially cutaway, fully cross-sectional view of an embodiment wherein
the reinforcement member comprises separate first and second members secured together,
such as by welding, with each member having an L-shaped cross-section;
Fig. 7a is a partially cutaway, fully cross-sectional end view of an embodiment
wherein the reinforcement member includes a body having a first or lower portion that is
T-shaped in cross-section and a second or upper portion having a variable height including
an apex, with the body being fabricated from a single piece of material, such as by
stamping, forging, or the like;
Fig. 7b is a partially cutaway, fully cross-sectional end view of an embodiment
wherein the reinforcement member includes a body having an L-shaped cross-section and
having a variable height including an apex, with the body being fabricated from a single
piece of material, such as by stamping, forging, or the like;
Fig. 8 is a partially cutaway, side elevational view of a portion of a bushing body
including a tip plate with a reinforcement member comprising a body with an arcuate
profile having a variable height and a single apex;
Fig. 9 is a view similar to Fig. 8, but with the second portion of the body of the
reinforcement member having a height that increases substantially linearly from each end
thereof to create an inverted V-shaped profile; and
Fig. 10 is a view similar to Figs. 8 and 9, but with the second portion of the body of
the reinforcement member including two apexes to create an inverted W-shaped profile for
a two tip plate bushing.
DETAILS DESCRIPTION AND PREFERRED
EMBODIMENTS OF THE INVENTION
Reference is first made to Fig. 1, which is a schematic illustration of a portion of a
prior art fiber-forming structure wherein a plurality of gussets G1, G2 are attached to the
upper surface Su of a tip plate T (shown in phantom). The tip plate T is formed from
platinum, alloys thereof or a like material, and includes between about 10 and 100 small
tips or orifices O through which molten material, such as glass, passes (see, for example,
Figs. 4a and 4b). The molten material contacts the upper surface Su of the tip plate T prior
to it passing through the orifices O to be drawn into fibers. The gussets G1, G2 are formed
from platinum, alloys thereof, or a like material. As is known in the art, electric current is
typically supplied to the tip plate T from a power source, such as a transformer, to create
resistive heating. This heating helps to maintain the glass or other material in a molten
state as it passes through the orifices O or tips in the plate T. As noted above, a more
detailed description of the overall process is found in the commonly assigned Bobba '727
and Carey '430 patents incorporated herein by reference.
The tip plate T is supported in a bushing body (not shown) having sidewalk and
end walls. Together, the side and end walls serve as a frame for supporting or carrying the
tip plate T.
Over time, the bending stresses created by gravity, fiber tension and the weight of
the molten glass and the concomitant elevated temperature cause the tip plate T to sag,
primarily in the "middle" portion (that is, the portion located farthest away from the side
and end walls of the corresponding bushing body). It is well known that this sagging
reduces the effectiveness of the tip plate T, since it results in a non-uniform thermal
distribution and, hence, the creation of fibers of non-uniform diameters due to uneven heat
transfer to the cooling fins. Production of fibers of non-uniform diameters is undesirable,
and is usually the primary factor that necessitates retiring the tip plate T from service and
replacing it with a new or reconditioned one.
While the T-shaped gussets G1, G2 are initially capable of resisting the bending
stresses, creep causes a time dependent strain that produces a deflection. As the T-shaped
gussets Gl, G2 are simple prismatic beams, that is, constant cross section, the maximum
deflection must occur at the span midpoint under uniform loading. Hence, as shown in
Fig. 2, the gussets G1, G2 eventually bend or sag along with the tip plate T (note reference
numeral S designating the sagging in the vertical dimension shown for purposes of
illustration).
In an effort to combat this sagging, the present invention includes an improved
reinforcement member 10, which may either be used in place of the conventional gusset(s)
or may be formed by securing or attaching a separate strengthening member to a
conventional gusset(s). Figs. 3a and 3b each illustrate a tip plate T in phantom including a
plurality of spaced reinforcement members 10a, 10b falling into the latter category, and
constructed in accordance with one possible embodiment of the present invention. While
only two reinforcement members 10a, 10b are shown, it should be appreciated that more or
fewer may be provided, depending on the dimensions of the tip plate T and other aspects
of the particular application.
Specifically, as perhaps best shown by viewing Figs. 4a and 4b together with Fig.
3a, each of the plurality of reinforcement members 10a, 10b includes a body having a first,
lower portion 12. As should be appreciated from the foregoing discussion, this portion 12
may comprise a conventional gusset already coupled to the tip plate T, or may form part
(that is, the lower portion) of an uncoupled, complete reinforcement member 10 which is
intended to be secured directly to the planar upper surface of a tip plate T at various
strategic locations.
The lower portion 12 in the illustrated embodiment has a T-shaped cross-section,
including: (1) a relatively thin web 14 having a lower end, along which the weld W or
other bond, such as a mechanical joint, securing the reinforcement member 10a or 10b to
the tip plate T between adjacent rows of orifices O is formed; and (2) a transverse member
16 at the opposite end of the web 14 creating a substantially planar upper surface and
defining at least one, and preferably a pair of opposed flanges 18a, 18b. Alternatively, the
lower portion 12 may be formed from a single piece of T-shaped material fabricated using
stamping, extruding, forging, or other techniques, but this may increase the expense. At
the present time, the less expensive, and thus, preferred manner of forming the
reinforcement member 10a or 10b is by securing the transverse member 16 directly to the
web 14, such as by laser or TIG welding (note welds W in the embodiment shown in Figs.
4a and 4b). The lower portion 12 is preferably formed from platinum, alloys thereof or a
like material.
The reinforcement members 10a, 10b further include an upper portion 20, also
having a T-shaped cross-section including a web 22 and a transverse member 24. This
transverse member 24 thus creates at least one, and preferably a pair of opposed flanges
26a, 26b that define an upper surface US (see Fig. 4a). As with the lower portion 12, these
flanges 26a, 26b may be created using a separate piece of material welded or otherwise
bonded to the upper end of the web 22. However, the use of a single piece of material to
form the upper portion 20 is also possible, such as one constructed using known stamping,
or forging techniques. In this particular embodiment, and as perhaps best shown in Fig. 4a,
the lower end of the web 22 of the upper portion 20 may be attached to the upper surface
of the transverse member 16 of the lower portion 12, such as by welding or any other
means for forming a secure, permanent or semi-permanent bond. The upper portion 20
preferably is formed from the same material used to form the lower portion 12, which
materials are set out above.
The upper portion 20 of each reinforcement member 10a or 10b includes a profile
with a variable height that forms at least one apex A. Thus, in the embodiment of Fig. 3a,
the slope or height of the upper end 22a of the web 22 increases linearly from each end of
the reinforcement member 10a or 10b, such that the apex A is positioned substantially at
the midpoint M along the length thereof (which may also coincide with the midpoint
between the sidewalls of the bushing body (not shown, but see, for example, Figs. 8-10)).
Further, the web 22, in the illustrated embodiment, has triangular-shaped side portions 22b
and 22c, see Figs. 3a and 4b. The transverse member 24 (or members) also assist in
defining this profile.
The end result of this arrangement is that, in terms of susceptibility to bending
stress and creep, the maximum or peak resistance to bending is theoretically provided at
the midpoint M, which is the precise location where the sagging is typically the greatest.
Also, in this particular embodiment, the added weight is kept to a rninimum while still
providing the desired degree of reinforcement by providing the upper portion 20 with a T-
shaped cross-section, as opposed to simply using a solid block of material. By also
forming each reinforcement member 10a or 10b from separate pieces of material
sequentially welded together, the overall cost required for implementing this arrangement
may be minimized. This mode of construction may also allow for the reinforcement
members 10a or 10b to be easily retrofitted onto tip plates T already in service having
existing gusset(s) (in which case only the upper portion 20 of the embodiment shown in
Figs. 3a, 4a, and 4b need be provided).
In the embodiment of Fig. 3b, the profile of the upper portion 20, including the
transverse members) 24, varies in height and includes at least one apex A. However, the
web 22 is asymmetrical, with each side having a different slope. As a result, the apex A
does not fell at the midpoint M (note dashed vertical lines) between the ends of the lower
portion 12 of the reinforcement member 10a, 10b (or the sidewalls of the bushing body, in
the case where the ends of the lower portion 12 of the reinforcement member are
coextensive therewith). This arrangement or any variation thereof may be useful in special
situations where the location of the maximum bending stress across the tip plate T is not
necessarily at the midpoint M or other design criteria preclude placing the apex at the
midpoint. In these situations, the approximate location for placing the apex A may be
determined empirically or predicted using well-known analytical or other modeling
techniques, such as finite element analysis.
Fig. 5a is a side elevational view and Fig. 5b is a cross-sectional view of another
embodiment of a reinforcement member 110. In this embodiment, the lower and upper
portions 112,120 are defined by a single piece of material having a T-shaped cross-
section, but may be defined by two separate pieces of material. More specifically, the
lower portion 112 is defined by a lower portion 114a of a single, vertically oriented web
114. The lowermost end of this web 114 is attached to the surface of the tip plate T, such
as by welding, between adjacent rows of orifices O extending along the width thereof.
The upper portion 120 of the reinforcement member 110 includes an upper portion
114b of the web 114, as well as at least one transverse member 124 attached to the upper
end thereof. The transverse member 124 defines at least one, and preferably a pair of
opposed flanges 126a, 126b. As with the embodiments described above, the flanges 126a,
126b may instead be separately attached, such as by welding or other permanent or semi-
permanent bonding (see Fig. 5a). The upper portion 120 of the reinforcement member
110, including the transverse members) 124 and the upper web portion 114b, also has a
variable height when viewed in profile to define at least one apex A. As with the
embodiment in Fig. 3a, the apex A is shown as being located substantially at the midpoint
M between the ends of the reinforcement member 110. By positioning the apex A at this
location, which is typically where the maximum bending stress is created, the ability of the
corresponding portion of the tip plate T to resist sagging is greatly enhanced, which in turn
extends the service life. As noted above, it should be appreciated that the embodiment
shown in Fig. 5a could also be constructed such that the apex A (or multiple apexes; see,
for example, Fig. 10) does not coincide with the midpoint M. This arrangement may be
useful in cases where the maximum stress or bending might not be at the midpoint M or
other design criteria precludes placing the apex at the span midpoint.
Fig. 5a also demonstrates one manner in which apertures or openings 130 may also
be provided in the reinforcement member 110, such as in the web 124. These apertures or
openings 130 reduce the overall amount of material required during fabrication, and thus
reduce the cost and weight contribution of each reinforcement member 110. However, the
openings 130 are sized and strategically positioned such that no significant reduction in the
resistance to bending stresses or sagging results. In the example shown, three such
openings 130 are provided, but fewer or more may be provided. Also, while circular
openings 130 are shown for purposes of illustration, it should be appreciated that any
shape may be used, as long as the result is that the reinforcement in strength provided to
the tip plate T remains uncompromised. Moreover, while the openings 130 are shown in
the embodiment of Fig. 5a, it should be appreciated that any of the other embodiments may
benefit from their presence, either in the upper portion (see, for example, Fig. 9), the lower
portion (not shown), or in both portions of the reinforcement member (not shown).
It is believed that the reinforcement member 110 illustrated in Fig. 5a provides
optimal strength with minimal metal weight.
Another embodiment is depicted in the partially cutaway, partially cross-sectional,
end elevational view of Fig. 6a. In this embodiment, the reinforcement member 210 has a
lower portion 212 having a cross-section in the shape of an inverted "L." The lower end of
the web 214 of the "L" is secured to the surface of the tip plate T between adjacent rows of
orifices, such as by welding (note welds W). The upper portion 220 of the reinforcement
member 210 is also L-shaped in cross-section, as perhaps best understood with reference
to the cross-sectional view of Fig. 6b. Thus, it too includes a web 222 that is secured to
the transverse member 216 of the lower portion 212, such as by welding, to provide the
resulting reinforcement member 210 with an F-shaped cross-section. This reinforcement
member 210 is thus integrally formed with the tip plate T by welding the I-shaped
member forming the lower portion 212 to the tip plate T, either before or after the L-
shaped member forming the upper portion 220 has been welded to the lower portion 212.
However, as noted above, it is of course possible, but more expensive, to create the entire
reinforcement member 210 from a single piece of material having an F-shaped cross-
section that is then welded directly to the tip plate T.
Although not specifically illustrated, it should also be appreciated that to reduce the
effects of sagging and extend the service life of the tip plate T, the upper portion 220 of the
reinforcement member 210 has a variable height when viewed in profile, and thus defines
at least one apex A. Indeed, in an embodiment of reinforcement member 210 where the
height increases linearly from the sides to the midpoint, the actual side elevational view
from the right side of Fig. 6b would be identical to one taken looking from the left or right
side of Fig. 3a, with the observer's eye at or near the horizontal plane defined by the tip
plate T. The view from the opposite, or left hand side of Fig. 6b would be similar to the
view in Fig. 5a, but without the flange 126a or 126b shown along the top of the
reinforcement member and with a partial or full length bead present where the web 222 of
the upper portion 220 is welded directly to the upper surface of the transverse member 216
of the lower portion 212.
Still another possible embodiment is shown in Fig. 7a. In this embodiment, the
entire reinforcement member 310, including the lower and upper portions 312, 320, is
fabricated from a single piece of material, similar to one version of the embodiment shown
in Fig. 5a. However, in addition to flanges 326a, 326b, the member 310 also includes
integral flanges 318a, 318b that add strengm and further help in resisting sagging. While
this embodiment uses more material and is thus slightly heavier than the one shown in Fig.
Sa (and also costs more to manufacture using current stamping or forging techniques), it
reduces the amount of welding required as compared to the embodiment of Fig. 3 a, since
welds are required only at the interface between the lower end of the web 314 and the
surface of the tip plate T. Also, it may find utility in situations where the tip plate T is
exceedingly wide, or others where a more substantial reinforcement is required.
A similar embodiment of a reinforcement member 310 formed of a single piece of
material having an L-shaped cross-section is shown in Fig. 7b. This reinforcement
member 310 also has a variable height profile with an apex (not shown). When viewed
from the right hand side of Fig. 7b, the view is similar to that of Fig. 5a (possibly without
the optional openings 130).
Up to this point, the reinforcement members 10,110,210,310 have been shown
and described for use on a single, substantially planar tip plate T that extends between a
pair of sidewalls in a bushing body (not shown). However, it is also possible to use the
reinforcement members 10,110,210,310 in situations where a "double-bottomed"
bushing is provided. This is illustrated in Figs. 8-10, with only one half of each "double-
bottomed" bushing shown in Figs. 8 and 9 (note centerline L), and a full "double-
bottomed" bushing shown in Fig. 10.
In the first embodiment, the reinforcement member 410 has an upper portion 420
similar to the others described above. The difference is that instead of an apex A formed
by linearly increasing the height from the spaced ends, the height is varied non-linearly
from each side so as to create an arcuate profile. Preferably, as with the other
embodiments, the apex A is located substantially at the midpoint M between the ends of
the reinforcement member 410 to provide the optimum resistance to bending stresses, and
hence, time-induced plastic deformation (creep). In this embodiment, the apex A does not
coincide with the midpoint between the sidewalls (only one sidewall S1 is shown in Fig.
8), which may fall at or near the centerline L.
It should also be appreciated that the embodiment of Fig. 8 may be formed like the
one in Fig. 3a, with the upper portion 420 having the arcuate profile separately welded or
attached to an upper surface defined by a transverse member 416 creating opposed flanges
418a or 418b (only one shown in Fig. 8). The lower portion 412 is in turn secured to the
surface of the tip plate T between adjacent rows of orifices O, and could possibly take the
form of an existing gusset G, with the upper portion 420 merely serving as an add-on
strengthening or reinforcement member. Both the end elevational and cross-sectional
views of this embodiment are substantially the same as those in Figs. 4a and 4b, but could
also be like those in Figs. 6a and 6b as well
Alternatively, the reinforcement member 410 with the upper portion 420 having the
arcuate profile may be fabricated from a single piece of material. Still another alternative
is to form the upstanding portion or web 422 from a single piece of material, and then
separately attach the curved transverse member 424, such as by welding. In any of these
cases, both the upper and lower portions 412,420 may have T-shaped or L-shaped cross-
sections (with both preferably having the same cross-sectional shape). Also, although not
shown in Fig. 8, it should be appreciated that either portion may include weight-reducing
apertures or openings.
Still referencing Fig. 8, it is further noted that in the illustrated embodiment, the
upper portion 420 stops short of the sidewall S1 as does the transverse member 416
defining the flanges 418a or 418b (only one shown). The clearance thus created allows for
the welder to gain access to the sidewall S1 so that a weld may be laid along the
corresponding end of the web 414. This clearance is particularly helpful in the case where
a plurality of closely spaced reinforcement members are provided (not shown).
The embodiment shown in Fig. 9 includes a combination of features taken from the
embodiments of Figs. 3a-4b, 5a, and 9. The upper portion 520 of the reinforcement
member 510 has an inverted, V-shaped profile with an apex A, and is formed from a
separate piece of material that is welded or otherwise secured to the transverse member
516 of the lower portion 512 (both of which may have a T-shaped or L-shaped cross-
section). A plurality of relatively small, strategically positioned openings 530 are also
provided in the upper portion 520, which as noted above decrease the weight of the
resulting reinforcement member 510 without substantially compromising the strength.
The upper portion 520 also creates a gap with the sidewall S1. As noted in the previous
paragraph, this is optionally done to provide access to the interface between the end of the
lower portion 512 and the sidewall S1.
In the embodiment shown in Fig. 10, the first noteworthy point is that the full
"double bottom" bushing B or bushing assembly is shown in cross-section, including the
spaced sidewalls S1, S2 and the tip plate(s) T. In the illustrated embodiment, the tip plates
T are integrally connected with an inverted V-shaped channel C. This channel C extends
along the length of the bushing B to provide enhanced structural support, and may be filled
with a refractory material R to insulate against heat losses to a water cooled support (not
shown). As is known in the art, the refractory material R usually also surrounds the entire
bushing B to not only thermally insulate it from the ambient environment, but also
electrically insulate it from other structures.
Secured to the surface of each tip plate T is a reinforcement member 610. The
reinforcement member 610 includes a lower portion 612, which as noted above may be
formed by the gussets having a T-shaped or L-shaped cross-section already present on the
tip plate T. The upper portion 620 in this embodiment has a profile that varies in height to
define two apexes A1, A2, one positioned substantially at the midpoint of each tip plate T.
Thus, the profile of the upper portion 620 has the shape of an inverted W. The upper
portion 620 may be formed of a single piece of material, including a continuous web 622,
or may have one or more transverse members 624 (two shown in Fig. 10) that are
separately welded in place. Alternatively, both the lower and upper portions 612,620
may be formed from a single piece of material, along with the transverse member 624
defining at least one, and preferably a pair of opposed flanges. The upper portion 620 is
also shown as having ends that are spaced from the sidewalls S1, S2 to permit access
during welding, but as described above, this is optional.
The foregoing descriptions of embodiments of the present invention are presented
for purposes of illustration and description. These descriptions are not intended to be
exhaustive or to limit the invention to the precise form disclosed. Obvious modifications
or variations are possible in light of the above teachings. For example, while only a single
reinforcement member or pair of reinforcement members are shown in the various
drawings, it should be appreciated that any number required to provide the desired degree
of reinforcement/resistance may be used at any spaced interval along the tip plate. Also,
the reinforcement members, whether formed from a single piece of material, multiple
pieces of material, or as add-ons to existing gussets, may be placed only at locations
susceptible to the maximum bending stresses, with other locations either having the
conventional gussets or no reinforcement Infinite variations on the shapes of the profiles
or cross-sectional shapes of the various reinforcement members or components thereof
may also be made, while still possibly achieving an acceptable level of
reinforcement/resistance. For example, while T-shaped, F-shaped, and inverted L-shaped
cross-sections create a minimal point of contact with the tip plate and minimize the added
weight, the reinforcement member could have a C-shaped, I-shaped, or E-shaped cross-
section as well, or any variation thereof. The embodiments described were chosen to
provide the best illustration of the principles of the invention and its practical application
to thereby enable one of ordinary skill in the art to utilize the invention in various
embodiments and with various modifications as are suited to the particular use
contemplated. All such modifications and variations are within the scope of the invention
as determined by the appended claims when interpreted in accordance with the breadth to
which they are fairly, legally and equitably entitled.
WE CLAIM
1. In a bushing assembly having a plate like structure comprising a plurality
of orifices for forming fibers from a fluid material, a member (10a, 10b)
for reinforcing the structure comprising:-
• a steel structure body having a first portion (12) having a profile with
variable height comprising at least one Apex (A);
• whereby the variable height profile and the at least one apex of the
body assists in reinforcing,
"characterized in that the said structure resists sagging, increases
service life, minimizes the amount of precious metal usage for
reinforcement, enhances the resistance of the structure from bending
stress and creep.
2. The reinforcement, member as claimed in claim 1, wherein the body is
comprised of a single piece of material.
3. The reinforcement member as claimed in claim 2, wherein the body
comprising the first and second portions has an inverted L-shaped (310),
T-shaped (312, 320), or F-shaped cross-section (210).
4. The reinforcement member as clamed in claim 3, wherein the second
portion of the body has an arcuate profile (420), an inverted V-shaped
profile (520), or an inverted W-shaped profile (620).
5. The reinforcement member as claimed in claim 1, wherein the body has a
length including a midpoint (M), and wherein the at least one apex (A) is
located substantially at the midpoint.
6. The reinforcement member as claimed in claim 1, wherein the bushing
assembly have spaced sidewalls (S1, S2) to which a first and second end of
the body are secured, respectively, and wherein the at least one apex is
located between the spaced sidewalls.
7. The reinforcement member as claimed in claim 1, wherein the bod/
comprises:
a first member defining the first portion for attachment to the structure;
and
a second member coupled with the first member, defining the second
portion and having the variable height profile with the at least one apex.
8. The reinforcement member as claimed in claim 7, wherein the first
member has a T-shape (12) or an inverted L-shaped (212) in cross-
section.
9. The reinforcement member as claimed in claim 7, wherein the second
member has a T-shaped (20) or an inverted L-shaped (220) in cross-
section and is formed from one or more component parts.
10.The reinforcement member as claimed in claim 7, wherein the second
portion has an arcuate profile, an inverted V-shaped profile, or an inverted
W-shaped profile.
11.The reinforcement member as claimed in claim 7, wherein the second
member provides a web (22) having an end that is welded directly to an
upper surface of the first member.
12.The reinforcement member as claimed in claim l, wherein the second
portion of the body comprises at least two apexes (A1, A2).
13.The reinforcement member as claimed in claim 1, wherein either the first
(112) or the second portion (120) of the body includes a plurality of
strategically positioned openings, whereby the openings (130) serve to
reduce the amount of material required to fabricate the reinforcement
member without compromising the strength thereof.
14.A bushing assembly for use in forming a plurality of fibers from a fluid
material at an elevated temperature comprising:
a structure having a plurality of orifices through which the fluid material
passes to form the fibers;
at least one reinforcement member (10a, 10b) having a first portion (12)
for attachment to the structure (T) and a second portion (20) having a
profile with a variable height having at least one apex (A),
whereby the variable height of the reinforcement member comprising the
at least one apex enhances the resistance of the structure to sagging and
extends the service life thereof while minimizing metal usage.
15.The brushing assembly as claimed in claim 14, wherein the fiber forming
structure is plate-like, and wherein the at least one reinforcement member
extends along a width dimension thereof.
16.The brushing assembly as claimed in claim 15, wherein a plurality of
independent, spaced reinforcement members extending along the width
of the plate-like structure.
17.The brushing assembly as claimed in claim 16, wherein the fiber-forming
structure has an upper surface to which the first portion of each of the
reinforcement members is welded.
18.The brushing assembly as claimed in claim 14, wherein the reinforcement
member is fabricated from either a single piece of material or at least two
pieces of material secured together.
19.The brushig assembly as claimed in claim 14, wherein the structure
provides at least one existing gusset (GO, and wherein the second portion
of the reinforcement member is attached to the gusset.
20. A method for reinforcement a plate or plate-like structure for forming
fibers from a fluid material supplied to a brushing, comprising:
securing at least one reinforcement member (10a, 10b) to the fiber-
forming structure, said reinforcement member comprising a first portion
(12) for attachment to the structure (T) and a second portion (20) having
a profile with a variable height having at least one apex (A),
whereby the variable height of the reinforcement member having the at
least one apex enhances the resistance of the structure to bending
stresses and extends the service life thereof while minimizing metal
usage.
21.The method as claimed in claim 20, wherein the securing step comprises
securing a plurality of independent reinforcement members to the fiber-
forming structure in a spaced relationship.
22.The method as claimed in claim 20, wherein the reinforcement member
comprises a first member providing the first portion and a second member
providing the second portion, and wherein the securing step comprises
securing the first member to the fiber forming structure, and securing the
second member to the first member.
23.The method as claimed in claim 20, wherein the fiber forming structure
comprises at least one existing gusset (G1), and said method further
includes attaching the first portion of the reinforcement member to the
gusset.
24.In a bushing assembly for forming fibers from a fluid material at an
elevated temperature using a bushing tip plate (T) having an upper
21
surface and a plurality of strategically positioned fiber-forming orifices, a
reinforcement member (10a, 10b), comprising:
a body having a lower-portion (12) and a web (22) for attachment to the
upper surface (20) of the bushing tip plate and an upper portion coupled
with the lower portion, said upper portion having a variable height profile
shaped for resisting both a bending stress created partially by the weight
of the material and a creep created partially by the elevated temperature
of the material over time in combination with the bending stress, said
profile including at least one apex (A),
whereby the profile of the bode,Including the at least one apex enhances
the resistance of the bushing tip plate to sagging and thereby
substantially extends the service life thereof while minimizing metal
usage.

In a bushing assembly having a plate like structure comprising a plurality of
orifices for forming fibers from a fluid mater, a number (10a, 10b) for reinforcing
the structure comprising:-
A T-shaped structural body having a first portion (12) having a profile with
variable height comprising a least one Apex (A); whereby the variable profile and
the atleast one apex of the body assists in reinforcing the structure against
sagging and extends the service life thereof while minimizing metal usage.

Documents:

1342-KOLNP-2003-FORM-27.pdf

1342-kolnp-2003-granted-abstract.pdf

1342-kolnp-2003-granted-assignment.pdf

1342-kolnp-2003-granted-claims.pdf

1342-kolnp-2003-granted-correspondence.pdf

1342-kolnp-2003-granted-description (complete).pdf

1342-kolnp-2003-granted-drawings.pdf

1342-kolnp-2003-granted-examination report.pdf

1342-kolnp-2003-granted-form 1.pdf

1342-kolnp-2003-granted-form 18.pdf

1342-kolnp-2003-granted-form 2.pdf

1342-kolnp-2003-granted-form 3.pdf

1342-kolnp-2003-granted-form 5.pdf

1342-kolnp-2003-granted-pa.pdf

1342-kolnp-2003-granted-petition under rule 137.pdf

1342-kolnp-2003-granted-reply to examination report.pdf

1342-kolnp-2003-granted-specification.pdf

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Patent Number

233657

Indian Patent Application Number

1342/KOLNP/2003

PG Journal Number

14/2009

Publication Date

03-Apr-2009

Grant Date

01-Apr-2009

Date of Filing

17-Oct-2003

Name of Patentee

OWENS CORNING

Applicant Address

ONE OWENS CORNING PARKWAY, TOLEDO, OH 43659

Inventors:

#	Inventor's Name	Inventor's Address
1	BEMIS, BYRON, L.	10538 BLUE JAY ROAD, NEWARK, OH 43056
2	SULLIVAN, TIMOTHY, A.	84 STONINGTON CIRCLE, NEWARK OH 43055
3	SMITH, KEVIN, D.	908 SHARON GLYN DRIVE, NEWARK, OH 43055
4	WOLF, DAVID, H.	95 NORTH 31ST STREET, NEWARK, OH 43055
5	EMERSON, JACK, L.	450 RENAE DRIVE, NEWARK, OH 43055
6	PURNODE, BRUNDO, A.	740 WEST MAPLE, GRANVILLE, OH 43023
7	TRACY, JAMES, P.	54SEALEYBARK TRAIL, CONCORD, NC 28027
8	STREICHER, WILLIAM, L.	734 NEWARK ROAD, GRANVILLE, OH 43023

PCT International Classification Number

C03B 37/083

PCT International Application Number

PCT/US2002/20167

PCT International Filing date

2002-06-25

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	09/894,672	2001-06-27	U.S.A.