ASSEMBLY OF A REAMING TOOL, CONSISTING OF CLAMPING PART, REAMING BIT AND A DISMANTLING KEY AND METHOD OF DISMANTLING OF THE REAMING TOOL

Abstract

Assembly of a reaming tool, that includes a clamping part, a reaming bit and a dismantling key. The clamping part is provided with a driving pin and with a hollow seating central protrusion. The reaming bit is provided with a central through opening for depositing on the seating central protrusion of the clamping part. On a cutting part a frontal surface is provided with a central axis on which a through conical opening is provided. On the clamping part of the reaming tool a frontal abutting surface is provided. In the central axis of the clamping part, there is a tubular conical protrusion, whose apex angle is smaller than the apex angle of the through conical opening. On the frontal abutting surface of the clamping part at least one recess is provided corresponding in shape to the functional part of the dismantling key.

Claims

1. Assembly of a reaming tool, comprising a clamping part, a reaming bit and a dismantling key, the clamping part is provided with a driving pin and with a hollow seating central protrusion and the reaming bit is provided with a central through opening for depositing on the seating central protrusion of the clamping part, wherein on a face of a cutting part there is a driving opening and both parts are connected by a clamping screw provided at one end with a cylindrical head having an internal hexagonal opening and at an opposite end with an external thread which interacts with the internal thread of the tool clamping part, wherein on the cutting part a frontal annular surface is provided, in its central axis a through conical opening is provided and on the clamping part of the reaming tool a frontal abutting surface is provided and in a central axis of the clamping part, there is a tubular conical protrusion, whose apex angle of the cone is smaller than the apex angle of the through conical opening, and on the frontal abutting surface of the clamping part at least one recess is provided corresponding in shape to a functional part of the dismantling key.

2. Assembly according to claim 1, wherein on the frontal abutting surface of the clamping part there are two radially formed recesses arranged oppositely to each other in the same axis and in the tubular conical protrusion a connection through opening is provided for complete insertion of the functional part of the dismantling key.

3. Assembly according to claim 1, wherein cutting part is made of a sintered carbide monoblock.

4. Assembly according to claim 1, wherein the body of the cutting part is made of a monobloc of sintered carbide or hard steel, on which cutting tips are arranged made of superhard cutting materials.

5. Assembly according to claim 1, wherein the functional part of the disassembly key is made of hardened steel and has a non-circular, square or oval profile in cross section.

6. Assembly according to claim 1, wherein the disassembly key is made as an Allen key.

7. Method of dismantling of a reaming tool according to claim 1, wherein after removing the clamping screw, the parts are disassembled by inserting a functional part of the dismantling key into at least one semi-open recess and the parts are disassembled by angularly rotating it.

8. Method dismantling of a reaming tool according to claim 7, wherein the parts are disassembled by, by inserting the functional part of the disassembly key into one of the semi-open recess and then inserting it through the opening up to the other semi-open recess and by angularly rotating the functional part of the dismantling key, the parts of the assembly of a reaming tool are disassembled.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0010] The invention will be explained in more detail by means of drawings, where FIG. 1 shows the exploded assembly of the reaming tool and its clamping part, FIG. 2 is a view of the clamped assembly of the reaming tool and its clamping part, FIG. 3 is a view of the clamping part of the assembly in the first embodiment, FIGS. 4,5 show an assembly of a reaming tool, its clamping part and a dismantling key according to the invention in the first embodiment, FIG. 6 is a view of the clamping part of the assembly in a second embodiment, FIGS. 7, 8 show an assembly of a reaming tool, its clamping part and a dismantling Allen key according to the invention in a second embodiment and FIGS. 9 and 10 illustrate in detail how the reaming tool and clamping part are assembled together according to the invention.

DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

[0011] FIGS. 1 and 2 show a part of the reaming tool assembly 1 with a cutting part 2 and its clamping part 3, still without the dismantling key. The assembly comprises the cutting part 2 and this is mounted on the clamping part 3 and the both parts are connected by a clamping screw 4 provided at one end with a cylindrical head 26 having an inner hexagonal opening 16 and a conical outer seat 15 which abuts a conical inner seat 13 of the cutting part 2, and at the other end of the screw 4 there is an external thread 14 which engages with an internal thread 12 of the clamping part 3.

[0012] On a frontal abutting surface 9 of the clamping part 3, a driving pin 11 is provided, which interacts with the driving opening 5 on the frontal annular surface 7 of the cutting part 2 and which serves to safely transfer the torque transmitted from the clamping part 3 to the cutting part 2. There is also a circumferencial recess 21.

[0013] On the cutting part 2, there is a frontal annular surface 7 and in its central axis 6 there is a through conical opening 8, and on the clamping part 3 there is the frontal abutting surface 9 and in its central axis 23 there is a tubular conical protrusion 10 whose apex angle of the cone is smaller than the apex angle of the through conical opening 8, whereas in the clamped state of the cutting part 2 and the clamping part 3 of the tool, their conical and frontal surfaces are securely adjacent to each other.

[0014] In the clamping part 3, a central channel 19 and side channels 27 are formed into which a cooling medium can be fed, which also serves as a lubricant. FIGS. 1 and 2 show the cutting part 2, the body 18 of which is made of sintered carbide or hard steel, on which cutting tips 17 of superhard cutting materials such as, for example, polycrystalline diamond, polycrystalline cubic boron nitride, cermet with silver solder are soldered. FIGS. 3 to 8 show the cutting part 2 which is made from a monoblock of sintered carbide. The design of the cutting edges of the cutting tips 17 is essentially irrelevant, so will not be explained here.

[0015] The central channel 19 and the side channels 27 for conducting the cooling medium are arranged in such a way that the cooling medium in the assembled state discharges preferably in the section of the cutting tips 17, and thus cools and lubricates the machining section.

[0016] Assembly of the tool with the cutting part 2 and the clamping part 3 is carried out by tightening the clamping screw 4 so that the conical inner surface of the through conical opening 8 of the cutting part 2 first sits on the tubular conical protrusion 10 (FIG. 9), the apex angle .sub.1 of which is smaller than the apex angle .sub.(2) of the through conical opening 8, whereas between the frontal surfaces 7, 9 a reasonable clearance of preferably 0.05-0.2 mm is created. Further tightening of the clamping screw 4 (FIG. 10) causes elastic deformation of the wall of the tubular protrusion 10 and thus allows the frontal surfaces 7, 9 of the parts 2, 3 to be seated, whereby the conical surfaces of the conical protrusion 10 and the through conical opening 8 fit securely together and thus become firmly adhered. As a result, even when the clamping screw 4 of the already clamped parts 2, 3 is screwed out, the connection between clamped parts 2, 3 is not freely detachable. Therefore, it is necessary to dismantle the assembled cutting bit and its clamping part (FIGS. 5 and 8) in a special way. This is carried out by means of the dismantling key 22, in the illustrated example Allen key, which is also part of assembly 1, by angularly turning its functional part 20, which interacts with the frontal annular surface 7 (FIG. 1), thereby separating the cutting part 2 and the clamping part 3.

[0017] Method of disassembling the cutting and clamping part of the tool in the first embodiment of FIGS. 3, 4, 5 is carried out in a following way:

[0018] After removing the clamping screw 4 (FIG. 4), the functional part 20 of the disassembling key 22 is inserted into the recess 24 and by turning it at an angle (FIG. 5), the parts 2,3 of the assembly 1 are disassembled.

[0019] Method of disassembling the cutting and clamping part of the tool in the second embodiment of FIG. 6, 7, 8 is carried out in the following way:

[0020] After removing the clamping screw 4 (FIG. 7), the functional part 20 of the disassembly key 22 is inserted into one of the two radially formed recesses 24 arranged oppositely to each other in one axis, and subsequently functional part 20 of the dismantling key 22 is inserted through the opening 25 up to the second recess 24, and by angularly rotating the functional part 20 of the dismantling key 22 (FIG. 8), the parts 2, 3 of the assembly 1 are disassembled.

LIST OF REFERENCE SIGNS

[0021] 1Assembly [0022] 2Cutting part [0023] 3Clamping part [0024] 4Clamping screw [0025] 5Driving opening [0026] 6Central axis of the cutting part [0027] 7Frontal annular surface [0028] 8Through conical opening [0029] 9Frontal abutting surface [0030] 10Tubular conical protrusion [0031] 11Driving pin [0032] 12Internal thread [0033] 13Conical inner seat [0034] 14External thread [0035] 15Conical outer seat [0036] 16Inner hexagonal opening [0037] 17Cutting tips [0038] 18Body of cutting part [0039] 19Central channel [0040] 20Functional part [0041] 21Circumferrential recess [0042] 22Dismantling key [0043] 23Central axis of the clamping part [0044] 24Recess [0045] 25Connection through opening [0046] 26Cylindrical head [0047] 27Side channel