COLLET

Abstract

A collet for attachment to distal portion (16) of a die-transporting shank (17), which comprises: a body (13) having a through hole (2) in its centre; said hole (2) consisting of three sections (3, 6, 7); first section (3) adjacent the proximal end (4) of the body (13), shaped to receive a protrusion on the shank distal portion (16); second section (6) adjacent the first section (3), linking the first section (3) to third section (7); said third section (7) opening to distal end (11) of the body (13); and an insert (14) having a through hole (10) in its centre, fitted into the third section (7); said insert hole (10) being smaller in diameter than that of the second section (6); distal portions of the body (13) and the insert (14) being of frusto-conical shape, having a flat-ended insert portion (12) extending beyond the distal end (11) of the body (13).

Claims

1.-18. (canceled)

19. A collet for attachment to distal portion of a die-transporting shank, comprising: a body made of elastic material having a through hole in its center; said hole consisting of three sections; first section adjacent the proximal end of the body, shaped to receive a protrusion on the shank distal portion; second section adjacent the first section, linking the first section to third section; said third section opening to distal end of the body; said second section is smaller in smaller in diameter compared to the first section and third section; and an insert made of material which is harder than the body having at least one through hole, fitted into the third section; said insert hole being smaller in diameter than that of the second section; distal portions of the body and the insert being of frusto-conical shape, having a flat-ended insert portion extending beyond the distal end of the body; wherein said edges at which the second and the third sections meet, forms a step within the through hole of the body which stops the insert from passing into the second section.

20. The collet as claimed in claim 19, wherein the second section is circular.

21. The collet as claimed in claim 20, wherein the third section is circular.

22. The collet as claimed in claim 21, wherein the insert is cylindrical.

23. The collet as claimed in claim 22, wherein distal end of the insert is circular, rectangular, or square.

24. The collet as claimed in claim 23, wherein the body hole also consists of fourth section opening to the proximal end of the body, flared toward said proximal end to facilitate reception of the protrusion on the shank distal portion.

25. The collet as claimed in claim 24, wherein the first and the fourth sections are rectangular.

26. The collet as claimed in claim 25, wherein the elastic material is rubber.

27. The collet as claimed in claim 26, wherein the insert is made of resin or plastic which is anti-static, and it is harder than the body.

28. The collet as claimed in claim 27, wherein the insert is made of polyoxymethylene plastic.

Description

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0025] The invention will now be described in greater detail, by way of example, with reference to the accompanying drawings, in which:

[0026] FIG. 1 is a perspective view of a collet blank according to the invention;

[0027] FIG. 2 is a top view of the blank;

[0028] FIG. 3 is, according to the invention, a perspective view of the blank and an insert prior to insertion into centre hole of the blank;

[0029] FIG. 4 is a side view of the blank and the insert;

[0030] FIG. 5 is a perspective view of the blank and a flanged insert prior to insertion into the centre hole of the blank;

[0031] FIG. 6 is a side view of the blank and the flanged insert;

[0032] FIG. 7 a perspective view of one form of a collet according to the invention;

[0033] FIG. 8 a perspective view of another form of the collet; and

[0034] FIG. 9 is a side view of a die-transporting shank, and the blank and the insert having their distal end portions ground.

[0035] As shown in FIG. 1, the cylindrical collet blank 1 has a through hole 2 in its centre, and said hole 2 consists of a plurality of sections. First section 3 adjacent proximal end 4 of the blank 1, is rectangular, shaped to receive a protrusion on distal portion of a die-transporting shank. Second section 6 (as shown in FIG. 4) adjacent the first section 3, is circular, and links the first section 3 to third section 7 (as shown in FIG. 4). Said third section 7 is circular, and opens to distal end of the blank 1. Apart from that, the blank hole 2 also consists of a fourth section 5 which opens to the proximal end 4 of the blank and is flared toward said proximal end 4 to facilitate reception of the protrusion on the shank portion.

[0036] The collet blank 1 is made of rubber, via a die-casting process whose steps comprise: designing a mould of a plurality of collet blanks 1, said mould consisting of a male and a female units; heating a substrate sheet; compressing the sheet between the male and the female units; releasing the units and removing compressed sheet from the units; and deflecting the sheet to singulate the blanks 1 off the sheet.

[0037] As shown in FIG. 2, the top view shows shape of each section 3, 6, 7, 5 of the hole 2. The first 3 and the fourth 5 sections are rectangular, and the second 6 and the third 7 sections are circular. The second section 6 is smaller in diameter compared to the third section 7. Edges 8 at which the second 6 and the third 7 sections meet, forms a step which stops an insert from passing into the second section 6.

[0038] As shown in FIGS. 3 to 6, the insert can be cylindrical 9 or flanged 19 on its distal end. The insert which has a through hole 10, 20 in its centre, is fitted into the third section 7 of the hole 2. Diameter of the insert hole 10, 20, which can be as small as 0.085 mm, is smaller than diameter of the second section 6.

[0039] The insert 9, 19 is made of resin or plastic, e.g. polyoxymethylene plastic, which is anti-static and harder than the blank 1, using a milling machine. The process of making the insert 9, 19 comprises steps of: cutting a substrate sheet into a form of a plurality of inserts 9, 19; drilling a centre hole 10 for each of the inserts 9, 19; and singulating the inserts 9, 19 off the sheet.

[0040] As shown in FIG. 7, the collet 15 comprises: a body 13 and an insert 12 fitted in the hole 2 of the body 13. Distal portion of the body 13 and the insert 14 is of frusto-conical shape, wherein the flat-ended insert portion 12 extends beyond the distal end 11 of the body 13.

[0041] As shown in FIG. 8, the collet 21 is of the same configuration as FIG. 7, but distal portion of a body 22 and an insert 23 is sliced into a rectangular or square shape.

[0042] As shown in FIG. 9, ends of the body 13 and the insert 14 is of a frusto-conical shape which has a flat-ended insert portion 12 extending beyond the distal end 11 of the body 13. The shape is formed by subjecting distal portions of the blank 1 and the insert 9, 19 fitted in the third section 7 of the hole 2, to a grinding process. During use, the collet 15 is fitted onto distal portion 16 of the shank 17. The first 3, second 6, and fourth 5 sections accommodate a protrusion of the shank distal portion 16.