Title of Invention	BORING TOOL
Abstract	Disclosed herein is a boring tool with a tool carrier (holder), at the front face (side) of which replaceable cutting inserts are mounted and which has a shank (for mounting the tool in the machine spindle) at its opposite end, and with an adjusting mechanism (unit) for minimizing the boring system related tolerance error.

Full Text

This invention relates to a boring tool with a tool carrier (holder), at the front face (side) of which replaceable cutting inserts are mounted and which has a shank (for maiming the tool in the machine spindle) at its opposite end, and with an adjusting mechanism (unit) for minimizing the boring system related tolerance error. A boring tool of the type mentioned above, however without adjusting mechanism but with a cutting insert is described in WO 98 / 07539. Moreover, corresponding boring tools with cutting inserts are described in EP 0 088 505 Al, EP 0 181 844 Bl, DE 27 30 418 C2, EP 0 054 913 Bl anode 27 51 255 C2 or DE 44 16 040 Al. The indexable inserts used, the tool carrier with seating for the index able inserts as also the boring spindle can however be manufactured accurately to dimension only within the scope of a certain tolerance. Deviations from the specified dimension (size) of the above mentioned components add up, which in the end result leads to, that tolerances of diameter of the drill can be maintained in the range of+/ - 0.15 mm. When an one-edged boring tool is used, the bore diameter changes during the service life of the cutting insert as a result of change in width of the wear land. Furthermore, as a result of wear, there is also an increase in the radial force, which often limits the service life of the boring tool or of the cutting inserts in use, because tolerance of diameter is not within the permissible range. Hence, in practice, only in few cases, it is possible that before the first cutting operation the entire system of the boring tool including the tool carrier, indexable inserts and the spindle permanently adhere to the tolerance limit in order to achieve an overall permissible tolerances of the diameter of 0.3 mm within the framework of the service life of the cutting inserts. Added to this, often smaller tolerances of diameter of+/ - 0.1 mm or less are specified. In order to solve this problem, the use of a radially adjustable seating arrangement of the drill is suggested, which can be implemented via an additional tool adapter, which however has the disadvantage of being very expensive. At present, in the market, a tool carrier with an adjustable mechanism (unit) is available, in which in the tool carrier a radially arranged (located) conical bore is provided, in which a radially adjustable cone is screwed-in, which is pointedly '"pressed" on one side in the relatively narrow (tight) regions of the tool carrier, whereby tiie deviations in tolerance can be corrected in the relatively narrow regions. The machined diameter of the bore can, depending upon the setting, become greater than the nominal diameter. The advantage of this invention is that the force applied via the cone is effective only in a narrow region of the tool carrier. In practice, especially at very high cutting speeds, this leads to the tendency of the tool carrier to vibrate. Besides this, because of the cone used in this invention, a non uniform distribution of masses is effected, which leads to clear unbalance and which especially at high cutting speeds of 500 m / min or higher has a considerable effect. Hence, it is the task of the present invention to improve the adjusting unit mentioned at the beginning, in order to minimize the boring system related tolerance errors. The boring tool described in the patent claim 1 solves this problem. The solution to this problem as per this invention lies therein, that the tool carrier has on each of diametrically opposite sides slot shaped openings, which are located eccentrically in a plane perpendicular to the longitudinal axis of the tool carrier. Further, each of the slot shaped openings have at the side opposite to the tool carrier longitudinal axis a cylindrical shaped expansion (opening) in each of which a bolt is mounted, whose size corresponds to the size of the cylindrical surface. Out of these, the first bolt is connected to an adjustable cone via a double-threaded screw mounted crosswise to the tool carrier. This adjustable cone is seated (rests) in a cone shaped opening in the outer surface of the tool carrier. By rotating the double threaded screw, the distance to the first bolt can be adjusted, whereby depending upon the distance adjusted, the extent to which the slot shaped opening that is located here widens (opens-up) or slackens can be defined. The second bolt can be tensioned against the tool carrier with the help of a threaded bolt, which engages into a through-threaded bore in this bolt, whereby it counters the corresponding strain experienced by the tool carrier in the region of the slot shaped opening located here. Compared to the prior art, the above-mentioned solution has many advantages. Firstly, with the diametrically opposite located slot shaped openings two defined regions are achieved in which the tool carrier can on its one side be widened and strained on the other side. Moreover, with the second tension able bolt that is located in the region of the slot shaped opening where a strain is produced, a counter-force is effected against the force apposed via the adjustable cone and as a result vibrations of the tool carrier are prevented. Further, with the adjustable cone, which is screwed-on into the double-threaded screw, a very fine adjustment and because of this a very sensitive widening of the concerned region of the slot shaped opening can be achieved at this side. As against the version known from the prior art, in which a threaded cone was screwed-in into a specified bore of the tool carrier, which corresponding to the extent of the widening (opening-up) is extremely susceptible to wearing, in the present invention the force causing the widening (opening-up) is effected through contact of the adjustable cone-surface area and the corresponding cone-shaped surface area of the opening in the tool carrier. Moreover a maximum stiffness (rigidity) of the tool carrier is achieved through the use of the two bolts. Further, with the present adjusting mechanism (imit), which consists of the two bolts, the double-threaded screw, the adjustable conical screw and the threaded bolt, one can achieve by far a better balancing of the imbalance, that means, the residual unbalance compared with the embodiment known from the prior art is minimum. Finally, with the adjustable mechanism (unit) as per the present invention one can achieve a considerably higher ultimate tolerance of boring system, which is restricted to ±_0.1 mm, preferably to ±.0.05 mm. A more detailed description of the present invention is given in the sub-patent claims. Thus, the above-mentioned bolts are mainly located parallel to one another that means, the bolts are located mirror symmetrically to a transverse axis passing through the center of the tool carrier. For corresponding arrangement of the cone-shaped openings diametrically opposite to one another, this invention also allows one to selectively provide the adjustable cone on the one or the other side or on the opposite side of the tension able coater bolt If required, the above-mentioned bolts can have a similar geometry (diameter, length). Within the scope of the present invention, such embodiments (of the invention) also there, in which on both the diametrically opposite sides an adjustable cone, a double-threaded screw and a bolt are provided as respective adjusting mechanism (unit). In this case a similar possibility is given for the adjusting and countering on both sides. According to another embodiment of the present invention, in the tensioned condition, the bolts are having a surface-to-surface contact in the cylindrical shaped openings, however at least linear contact along their longitudinal stretch. Thus, advantageously a blocking or jamming of the bolts is avoided. As per another embodiment of the present invention, the adjusting mechanism (imit) is housed in the region of an enlarged section of the tool carrier, which is located adjacent to the shank section of the tool carrier. With this measure one achieves a maximum possible horizontal-swing (sweep) of the tool carrier face with the cutting inserts mounted on it. In order to make the expandability or straining (upending) of the tool carrier in the region of the slot shaped openings easier, the enlargements in the tool carrier are provided with lateral recesses (between the slot shaped regions) or expressed in other words, the enlargement of the tool carrier on the sides, at which the slots are there, is realized individually or reinforced. Preferably the width of the slot lies between 0.1 mm to 4 mm. According to another embodiment of the present invention the diameter of the slot shaped opening and of the bolt that is mounted in it is at least twice as large as the width of the slot shaped openings. Preferably the diameter of the first bolt or of the corresponding slot shaped openings is 20 % larger than the diameter of the second bolt (for the countering) or the corresponding slot shaped openings. Finally, as per a further improvement of the invention, the length (depth) of the slot shed openings is selected in such a way, that the distance of the openings which accommodates the bolts is at least as large as the width of the tool carrier end at which the cutting inserts are mimed. An example of the invention is illustrated in the drawings. It shows: Figure 1 and 2 in each case perspective schematic views of tool carrier with integrated adjusting mechanism (unit) as seen from different angles and Figures the respective (by excluding the tool carrier) adjusting and countering elements according to Figure 1, As already mentioned at the beginning, boring tools with a tool carrier, which have at one end a tool shank for the clamping of the tool carrier in a machine spindle and replaceable cutting inserts at the opposite end are already known as per prior art. For more details one is requested to refer to WO 98/07539. Figure 1 and 2 show a schematic view of a tool carrier 1 (without the end section with seating for tool bits, in which the cutting inserts are mounted). This tool carrier has a tool shank 7 and also adjacent to this an enlarged section 12 of the tool carrier, which stretches over a part of the longitudinal axis. The adjusting mechanism for reducing the boring system related tolerance is located in this enlarged section. This adjusting mechanism consists of two bolts 2,3, which are mimed in, correspondingly designed cylindrical shaped openings having slot shaped openings 5,8 at the ends. The bolt 2 with the larger diameter has a crosswise threaded bore in which at one end a double-threaded screw 11 is mounted. On the other end of the double threaded screw 11 an adjusting cone 9 is screwed-in by using a corresponding internal thread. The outer surface of the adjusting cone 9 has a conical shaped surface, which fits in a conical recess of the tool carrier 1. This conical shaped recess is suited to the angle of the adjusting cone 9. On the side opposite to bolt 2 a bolt 3 is mounted, which also has a crosswise threaded bore in which a threaded bolt 4 is mounted. As shown in Figure 1 and 2 the enlarged section of the tool carrier has lateral recesses 6 and 10 on the opposite sides. The adjusting mechanism functions as follows: When the tool is set (adjusted) for a particular diameter, the adjusting elements 2,3,4,9 and 11 are in a fully slackened (relaxed) state. Thus threaded bolt 4 and the double-threaded screw 11 are loosened. In order to achieve a setting from A to B according to Figure 1, the double threaded screw 11 is tightened (screwed-in) in the radial direction towards the center of the tool. Hereby the adjusting cone 9 moves inwards, that means, the distance of the adjusting cone 9 to the bolt 2 - whose position 2 is fixed in the tool carrier - is reduced. As a result of the widening (expansion) of the slot shaped opening 8, effected via the concerned conical surface and a simultaneous contraction of slot 5 located on the opposite side, a bending of the tool carrier is caused, that means, a horizontal-swing (sweep) of the carrier at its front end from A to B. The bolt 2 is simultaneously pressed against the side of the corresponding cylindrical shaped opening of the slot 8, whereby at least a linear contact or a surface to surface contact along its longitudinal axis is achieved, that effects an additional studding and stabilization of the tool carrier 1. In order to achieve a further stiffening of the tool carrier 1, after the setting of the diameter via the double-threaded screw 11, by turning (rotating) the threaded bolt 4 the bolt 3 is subjected to a force acting radially outwards. Thus the bolt 3 is pressed at least linearly against the tool carrier or the corresponding cylindrical shaped opening. This is effected by supporting (pressing) the other end of the bolt 4, which is radially inside, against a corresponding surface in the tool carrier 1. The bolt 3, on which a radially outward directed force acting perpendicular to its longitudinal axis is apposed, produces an abutment in the region of the slot end 5, whereby vibrations of the tool carrier are prevented (due to the reduction in the width of the slot 5 and back to original position). With help of the bolt 2, the double-threaded screw 11 as well as the adjusting cone 9 and the widening (expansion) caused by them on the slot 8 on the one hand and the countering due to tensioned bolt 3 on the other hand, a maximum stuffiness of the tool carrier 1 is achieved. Because of the virtually complete fulfillment of all requirements necessary for the setting in the tool carrier 1, a fairly good compensation of the unbalance is achieved, that means, the residual unbalance is minimized. Further an optimal setting or bending (e.g. A to B) of the tool carrier can be achieved via the adjusting cone 9 and because of this the range of tolerance can be kq)t to minimum. The adjusting elements of the mechanism can also be manufactured at a low cost, since one can use standard components, such as bolts 2, 3, the double-threaded screw 11, the threaded bolt 4 and adjusting cone 9. Principally it is possible to carry out the adjustment of tool carrier from both sides, that means, one can mount the adjusting cone 9 along with the double-threaded screw 11 in the region of the slot 5 instead of slot 8 and vice-versa moimt lie threaded bolt 4 on the opposite side. As a result of the exact functioning of the adjustment mechanism and the countering on the opposite side for removing undesired vibrations, the boring tool can be wear-reducing operated and in turn the service life of the cutting inserts in use can be increased. On the whole, the above-described boring tool is not only inexpensive to manufacture, but also easy to handle and as regards the purpose can be maintained stable and steady. WE CLAIM: 1. Boring tool with a tool carrier (1), at whose front face, replaceable cutting inserts are matted and which has a tool shank (7) at the opposite end, and with an adjusting mechanism for minimizing the boring tool related tolerance error characterized in that the tool carrier (1) has at each of the diametrically opposite sides slot shaped openings (5,8) which are located on a plane that is perpendicxxlar to the longitudinal axis of titer tool carrier (1), a cylindrical shaped opening being provided on each of the sides opposite to the tool carrier longitudinal axis, bolts (2,3) each having the size corresponding to the dimension of the cylindrical opening is maimed on each of the said opening, out of these two bolts, a double-threaded screw (11) having an inner part threaded into the bore of the bolt (2) of the one slot (8) and an outer part threaded into the cone (9), whereby rotation of the double-threaded screw (11) radially displaces the cone (9); and a bracing screw (4) threaded into the bore of the bolt of the other slot (5) and radially engagable with the body. 2. Boring tool as claimed in claim 1, wherein the bolts (2,3) are located parallel to one another. 3. Boring tool as claimed in claim 1 or 2, wherein the bolts (2,3) in the tensioned conditioned are having surface-to-surface contact or at least linear contact in the cylindrical shaped opening. 4. Boring tool as claimed in any one of claims 1 or 2, wherein the tool carrier has the adjusting mechanism (consisting of elements 2, 3, 4, 5, 8, 9, 11) in the region of an enlargement (12), which is located adjacent to the shank section (7) of the tool. 5. Boring tool as claimed in claim 4, wherein the enlargement (12) of the tool carrier has on the sides, which are offset to the slot shaped openings (5,8) at 90^ at the level, of the slot shaped openings (5,8) recesses (6,10), which reduce and in turn makes the enlargement (12) of the tool carrier (1) thinner. 6. Boring tool as claimed in any one of the claims 1 to 5, wherein the width of the slot shaped openings (5,8) lies between 0.1 mm to 4 nM. 7. Boring tool as claimed m one of claims 1 or 6, wherein the diameter of the cylindrical shaped openings and the bolts (2,3) mimed in it is at least twice as large as the width of the slot shaped openings (5,8), whereby preferably the diameter of the first bolt (2) or the corresponding cylindrical shaped openings is at least 20% larger than the diameter of the second bolt (3) or the corresponding cylindrical shaped opening. 8. Boring tool as claimed in one of claims 1 to 7, wherein the distance of the cylindrical openings accommodating the bolts (2,3) is at least as large as the width of the tool carrier (1) at the end, on which the cutting inserts are mounted.

Documents:

767-mas-2000 form-13 09-06-2011.pdf

767-mas-2000 power of attorney 09-06-2011.pdf

767-mas-2000 correspondence others 09-06-2011.pdf

767-mas-2000-abstract.pdf

767-mas-2000-claims filed.pdf

767-mas-2000-claims granted.pdf

767-mas-2000-correspondnece-others.pdf

767-mas-2000-correspondnece-po.pdf

767-mas-2000-description(complete)filed.pdf

767-mas-2000-description(complete)granted.pdf

767-mas-2000-drawings.pdf

767-mas-2000-form 1.pdf

767-mas-2000-form 26.pdf

767-mas-2000-form 3.pdf

767-mas-2000-other document.pdf