Title of Invention

AN IMPROVED DISPOSABLE RAZOR ASSEMBLY

Abstract

An improved disposable razor assembly comprising of a lubra strip (10) provided with two pips, a top cap (20) provided with two holes (ST) to accommodate the lubra strip on assembly machine and also four pips (PP) to accept the blades (30,40), spacer (50) and handle (60), two blades perforated precisely with holes for accommodating the top cap, pips as well as lubra strip, spacers used between two blades seat having precisely pitched holes to accommodate the lubra strip pips and top cap pips on one side of the platform and composite handle which is a combination of the handle and the seat (20), characterized in that the lubra strip is being assembled to the balance components of the disposable razor by a cold staking process to form a composite razor which gives a definite shaving geometry for achieving smooth and comfortable shave referring to figures 5A, 6, 7, 8, 9 and 10.

Full Text

Field of Invention : The present invention relates to wet shaving implements and is more particularly directed to a razor assembly having plurality of blades. It is generally known in the art to embed a blade in a plastic shaving head, the said head being permanently attached to a handle, or otherwise removable from a handle for replacement by another shaving head. However, products manufactured according to the process available in the art are expensive to manufacture and do not offer smooth and comfortable shave in the absence of a definite shaving geometry. It is further known in the art to provide a razor blade assembly which may be connected to and used in conjunction with a razor handle to facilitate shaving operation. U.S. Patent NO. 3724070 shows a blade assembly in which blade means are held between blade assembly surfaces adapted to engage the surface being shaved in front of and behind cutting edge portion of the blade means. Shaving efficiency may also be obtained by retaining the blade assembly as a whole stationary but permitting movement of individual components thereof in response to forces encountered during shaving. In U.S. Patent No. 4168571 there is shown a blade assembly in which the guard, cap and blade means are each moveable independently of each other in dynamic fashion Indian Patent No. 155035 - 2 - But while manufacturing the cartridge as per prior art it has been observed that there is possibility for bending of the blades while the base is formed by insert moulding. Furthermore, the process of gluing together or moulding, the components in the moulding machine in sequential manner does not result in a perfect shaving geometry and possibility of human error always remains. Accordingly, an object of the present invention is to provide an improved disposable razor which is normal in its constructional design and obviates all the disadvantages and drawbacks associated with conventional shaving blade cartridges and razors existing in the art. A further object of the present invention is to provide an improved disposable razor which is simple, but rigid in its construction, easy to operate, effective in its use and having overall flexibility in operation. Another object of the present invention is to provide an improved disposable razor consisting of a lubra strip which is a water soluble polymer compound with high impact polystyrene with a specific proportion and also injection moulded provided with two pips for location purpose and also having a specific profile for perfect matching of the shaving geometry on assembly. - 3 - Another object of the present invention is to provide an improved disposable razor wherein the pips provided on the lubra strip facilitate in line assembly on special purpose assembly machine and also facilitates the components to be firmly gripped on assembly with other components. A still further object of the present invention is to provide an improved disposable razor wherein the peculiar design of lubra strip facilitates for a cold staking alongwith other components to provide mechanical strength and close composite structure. In the present invention the disposable razor consists of Lubra Strip, Top Cap, two blades, Spacer and Composite Handle in which there is also a provision for a platform onto which the blades, spacer and cap with lubra strip are placed for assembly. The handle is a composite: moulding of platform and handle and hence plastic shaving head with blades cannot be detached. During Shaving the Lubra Strip Surface "LS" dissolves so as to give moisturised lubricating skin. The top and bottom blades are placed in such a way that each having a blade tangent angle in the range of 18 to 30° and a span in the range of 0.5 - 2.0 mm. The Bottom blade and Top Blade having protrusion of 0.03 ± 0.03 mm and 0.07mm ± 0.07mm respectively. Among the important geometrical relationships, blade tangent angle, protrusion and span are the important parameters in twin shaving system. - 4 - In twin shaving system the above said important parameters are maintained within critical limits to provide superior shaving characteristics. In this shaving system the two blades are placed parallel to each other and maintained a gap of 0.4 to 0.6 mm by placing spacer in between top and bottom blades so that both cutting edges are successively active on a single shaving stroke. The cutting edges are supported by spacer Teeth point (SP) to maintain parallel relation to one another. A guard structure (c) is provided on the platform of the handle in a fixed relation to the cutting edges to define desired geometrical relationship include the above referred to blade tangent angle, protrusion and span. Blade tangent angle is defined as the angle between the bisector of the included angle of a cutting edge ami a line from the cutting edge tangent to skin engaging surface immediately forward of that cutting edge. Protrusion is defined as the distance from cutting edge to a plane defined by skin engaging surfaces immediately infront of and behind the cutting edge, the distance being measured perpendicular to reference plane. The protrusion is positive when the cutting edge is located on the skin side of that plane and it is negative when the cutting edge is away from the skin than that plane. Span is defined as the distance between fthe cutting edge and the skin engaging surface forward of that cutting edge. In this invention the most important parameters are the two pips of the lubrication strip grinding through cap to locate in the holes of the platform which is integral with the handle. Four pips are also provided in the cap to accommodate the two blades and aluminium spacer. The perforations in the blades are precisely - c _ %manufactured at a specified distance from the tip of the blade to obtain span distance. The holes in the aluminium spacer axe also perforated to accommodate the pips of lubrication strip and pips of cap. This product is unique as the lubra strip is being assembled to the balance components of the disposable razor by a cold staking process as against fixing the same with the glue or moulding in a sequential manner. The process of fixing the lubra strip is by feeding the components in a linearly arranged manner into the assembly machine and then it is packed and placed into a specially designed nest onto which the other components arc; kept in a sequential manner in the subsequent stages. The pips are provided in lubxa strip to locate the top cap, blades, spacer and the handle in order and at the final stage it is being cold staked to form a composite razor which gives a definite shaving geometry for achieving smooth and comfortable shave. According to the present invention there is provided an improved disposable razor comprising of a lubra strip provided with two pips; a top cap provided with two holes to accomodate the lubra strip on assembly machine and also four pips to accept the blades, spacer, and the handle; two blades perforated precisely with holes for accommodating the top cap, pips as well as lubra strip ; spacers : used between two blades ; seat having precisely pitched holes to accommodate the lubra strip pips & top cap pips, on one side of the platform : composite handle which is a combination of the handle and the seat; characterised in that the lubra strip is being assembled to - 6 - the balance components of the disposable razor by a cold staking process to form a composite razor which gives a definite shaving geometry for achieving smooth and comfortable shave. The above and other features of the invention, including various novel details of construction and combinations of parts, will now be more particularly described with reference to the accompanying drawings in which:- Figure 1 : is a top view of the platform of composite handle which has holds to accommodate pips of top cap and lubra strip an guard structure "C". Figure 2 : is the front elevation of Fig.l. Figure 3 :' is sectional view taken along with a iine ITI-III. Figure 4 : is sectional view taken along with a line VJ-VI. Figure 5 : is an exploded perspective view shaving top blade, spacer and bottom blade having holes for accommodating pips of top cap and lubra strip and rectangular slots for whiskers to get cleared from shaving head. Figure 5A : is an exploded perspective view of the lubra strip and top cap showing the p.ips and holes on the top cap. Figure 6 : is the assembled shaving head. Figure 7 : is the front elevation of Fig.6. -7- 'Figure 8: is sectional view taken along line VIII - VIII, to show lubra strip riveting with handle. Figure 9: is a side ele\rational view of one form of razor in orporating the implement of Fig. 6. Figure 10: is sectional elevational view similar to Fig.8 but blade tangent angles BTA 1 and BTA 2 are shown. Figure 11: is sectional view similar to Fig.8 but show with span distance SI and S2. Figure 12: is sectional view similar to Fig.8, but shown with protrusion PROT1 and PROT 2. Figure 13: is sectional view similar to Fig.8 but show with top cap riveting with handle. The lubra strip (10) in Fig.5A is made out of water soluble polymer mixed with high impact polystyrene by injecting into multi impression mould in the ratio of 60 : 40 under 30 to 40 bar injection pressure. The lubra strip is provided with two pips (LSP) in order to assemble this with other components of the disposable as shown in Fig. 8. The lubra strip surface "LS" which is in contact with the skin during shave having a definite profile. Also this profile improves the gliding effect during shaving. Hence the lubra strip having lubricating -8- surface "LS" is moulded on injection moulding machine using multi impression mould. Top cap (20) is made out of polymer on an injection moulding machine, this component is provided with 4 pips (PI3) in order to assemble the handle as shown in Fig. 13. A flat surface (TS) in Fig. 5A is provided on this component: to accommodate lubra strip and two holes (ST) are provided to pass lubra strip pips (LSP) while assembling. The pips of top AP (PP) and lubra strip (LSP) are pressed together by cold form pressing in the assembly machine. After assembly this part acts as a clamp for blades and spacer. The two blades (30 and 40) are made out of special grade razor blade stainless and provided with 6 slots as shown in Fig. 5 to accommodate the top cap and lubra strip pips. The blades are hardened and tempered and cutting edges (CET & CEB) of blades. ^ - - - ' ¦¦¦" """(tm)" (30 and 40) are sharpened and duly sputtered with chrome to increase the blade edge life on special purpose vaccum sputtering machine. Then these blades are coated with Krytox PTFE Polymer to give smoothness during shaving. The bottom blade (40) is provided with 8 swarf slots (SS) as shown in Fig. 5 in order to swarf out of shaving -9_ head. The slots (BS) for top cap pips to pass are located with respect to cutting edges (GET & CEB) in order to give span distances SI and S2 as shown in Fig. 11 and 13. It is known that the shaving performance mainly depends upon the blade quality. Hence the kblades are hardened and temperated to 600-700 HV for improving blade life and quality, also duly sputtered with polymer coating for eliminating irritation and improving comfort. The spacer (50) made out of aluminium with a specific thickness is provided with 9 Nos. of teeth (SP) to give the strength to blade cutting edges (CET & CEB) during shaving. This part allows a top and bottom blades to be parallel to each other and maintains blade tangent angles (BTA1 & BTA2) within limits. Handle (60) is made out of polymer material in an injection moulding machine as shown in Fig. 9. This component has got precisely pitched holes on flat plane surface (BSS) in Fig.l to accommodate lubra strip pips and top cap pips. The two holes (LH) are used for lubra strip pips and other 4 holes (TH) are used for top cap pips. This part (60) is provided with guard portion (C) which is required to determine blade tangent angle (BTA1, BTA2) and span -10- distances. SI and S2 as shown in Fig. 10 and Fig.ll respectively. Also the serration (C) is made on the guard bar such that the serration profile will be minimum contact with skin and give better blading during shaving/A longitudinal rib (LR) is provided on the otherside of the guard portion to cover the blades, spacer and to maintain clamping pressure during assembly. The guard portion "O shown in" Fig. 8 and serration "SER" shown in Fig. 8 play vital role in shaving performance by pushing the hair closer to blade edge. The flat plane surface (BSS) on which holes on which holes (TH and LH) are provided allows the blades to remain parallel to each other. The four slots (SL) in Figs. 1 and 3 allow the sward to escape out of shaving head. The bottom side of flat plane surface (BSS) is provided with long handle portion (h) as shown in Fig. 9 to hold the razor during shaving. The portion (h) is provided with grooves (g) for grip during shaving as shown in Fig. 9. Referring to Fig. 10, this is illustrated the manner in which the blade tangent angles (BTA) is determined. The BTA of bottom blade BTA-1 is generated by a line a-b bisecting the included angle of the -11- bottom blade (40) and extending from cutting edge (CEB). The angle BTA-1 is completed by a second Line a-c, extending from bottom blade cutting edge (CEB) to a tangent point C on guard portion. The top blade tangent angle BTA-2 is defined by a line e-f similar to line a-b and line e-a extending from the top blade (30) cutting edge (CET). The angles BTA1, 13TA2 both fall within the range 18 to 30 degrees. Reffering to fig. 11 this is illustrated the manner in which the span (SI & S2) is determined. The span of bottom blade SI is the distance between the bottom blade cutting edge (CEB) and tangent point "C" of immediately preceding skin engaging surface i.e., guard portion. The span of top blade S2 is the distance between the top blade cutting edge (CET) and tangent point of immediately skin engaging surface i.e., bottom cutting edge. The span SI and S2 fall within the range of 0.5-2.0 m.m. -12- Referring to Fig.12 this is illustrated the manner in which the protrusion (PROT) is determined. The protrusion of bottom blade (40) PROT-1 is determined by extending a line c-e between the tangent points immediately preceding and following top cutting edge, i.e., from the guard tangent point "C" to the top blade cutting edge (GET). A line h-h is then extended tangent to the bottom cutting edge and parallel to the line c-e. The perpendicular distance between the lines c-e and h-h define PROT-1. The PROT-1 falls within the range 0.03+/- 0.03mm. The protrusion of top blade (30) PROT-2 is determined by extending a line a-o between the tangent" points immediately preceding and following bottom cutting edge i.e., from the top cap tangent point "O" to the bottom blade cutting edge. 1-j is then extended tangent to the top blade cutting edge and parallel to the lines a-o. The perpendicular distance between the lines a-o and 1-j defines PROT-2, the PROT-2 falls within the range of 0.03+/-0.03 mm. -13- The above described shaving system offers the advantage of single and economic construction, combined with parameters of shaving geometry leading to efficient, safe and comfortable shaving. The invention having been described in detail in connection with the preferred embodiments is to be taken as an example only, not to be restricted thereto. It will be easily understood by those of ordinary skill in the art that other variations and modifications can be easily made within the scope of disclosure. For example it is preferable under certain conditions that the shaving head is immovable. An alternative embodiment includes the head portion can be provided with pivot movement making the head and handle portion as separate parts. As a further example the blade means may include a single blade rather than the two blades arrangement described. -14- WE CLAIM: 1. An improved disposable razor assembly comprising of a lubra strip (10) provided with two pips; a top cap (20) provided with two holes (ST) to accommodate the lubra strip on assembly machine and also four pips (PP) to accept the blades (30,40); spacer (50) and handle (60); two blades perforated precisely with holes for accommodating the top cap, pips as well as lubra strip; spacers used between two blades seat having precisely pitched holes to accommodate the lubra strip pips and top cap pips on one side of the platform and composite handle which is a combination of the handle and the seat (20), characterized in that the lubra strip is being assembled to the balance components of the disposable razor by a cold staking process to form a composite razor which gives a definite shaving geometry for achieving smooth and comfortable shave. 2. An improved disposable razor assembly as claimed in claim 1, wherein the lubra strip (LS) is made out of water soluble polymer mixed with high impact polystyrene by injecting into multi impression mould in the ratio of 60 : 40 under 30 to 40 bar injection pressure, the lubra strip is provided with two pips (LSP) in order to assemble this with other components (ST, 10,20,30,40,50) of the disposable and the lubra strip -15- surface (LS) which is in contact with the skin during shave having a definite profile, also this profile improves the gliding effect during shaving and hence the lubra strip having lubricating surface (LS) is moulded on injection moulding machine using multi impression mould. 3. An improved disposable razor assembly as claimed in claim 1, wherein the blades (30,40) are manufactured from special quality stainless steel and the blades are hardened and temperated to 600-700 HV for improving blade life, quality and also duly sputtered with polymer coating for eliminating irritation and improving comfort. 4. An improved disposable razor assembly as claimed in claim 1, wherein the guard porition (C) and serrations play vital role in shaving performance by pushing the hair closer to blade edge. 5. An improved disposable razor assembly substantially as herein described and illustrated in the accompanying drawings. Dated this 2nd day of March, 1998. -16- An improved disposable razor assembly comprising of a lubra strip (10) provided with two pips, a top cap (20) provided with two holes (ST) to accommodate the lubra strip on assembly machine and also four pips (PP) to accept the blades (30,40), spacer (50) and handle (60), two blades perforated precisely with holes for accommodating the top cap, pips as well as lubra strip, spacers used between two blades seat having precisely pitched holes to accommodate the lubra strip pips and top cap pips on one side of the platform and composite handle which is a combination of the handle and the seat (20), characterized in that the lubra strip is being assembled to the balance components of the disposable razor by a cold staking process to form a composite razor which gives a definite shaving geometry for achieving smooth and comfortable shave referring to figures 5A, 6, 7, 8, 9 and 10.

Documents:

00332-cal-1998 abstract.pdf

00332-cal-1998 assignment.pdf

00332-cal-1998 claims.pdf

00332-cal-1998 correspondence.pdf

00332-cal-1998 description(complete).pdf

00332-cal-1998 drawings.pdf

00332-cal-1998 form-1.pdf

00332-cal-1998 form-2.pdf

00332-cal-1998 form-26.pdf

00332-cal-1998 form-3.pdf

332-CAL-1998-CORRESPONDENCE 1.1.pdf

332-CAL-1998-CORRESPONDENCE 1.2.pdf

332-CAL-1998-CORRESPONDENCE 1.3.pdf

332-CAL-1998-CORRESPONDENCE.pdf

332-CAL-1998-FORM 27 1.1.pdf

332-CAL-1998-FROM 27.pdf

332-cal-1998-granted-abstract.pdf

332-cal-1998-granted-assignment.pdf

332-cal-1998-granted-claims.pdf

332-cal-1998-granted-correspondence.pdf

332-cal-1998-granted-description (complete).pdf

332-cal-1998-granted-drawings.pdf

332-cal-1998-granted-examination report.pdf

332-cal-1998-granted-form 1.pdf

332-cal-1998-granted-form 2.pdf

332-cal-1998-granted-form 26.pdf

332-cal-1998-granted-form 3.pdf

332-cal-1998-granted-letter patent.pdf

332-cal-1998-granted-pa.pdf

332-cal-1998-granted-reply to examination report.pdf

332-cal-1998-granted-specification.pdf

332-CAL-1998-OTHERS.pdf