US3281920A

US3281920A - Metal cutting tool with an adjustable unit serving as chip breaker and clamp

Info

Publication number: US3281920A
Application number: US349994A
Authority: US
Inventors: Eriksson Stig Lennart
Original assignee: Fagersta Bruks AB
Current assignee: Fagersta Bruks AB
Priority date: 1963-03-08
Filing date: 1964-03-06
Publication date: 1966-11-01
Anticipated expiration: 1983-11-01
Also published as: DE1477299A1; GB990619A; CH436918A

Description

1965 s. L. ERIKSSO 3,

METAL CUTTING TOOL WITH N ADJUS LE UNIT SERVING AS CHIP BR ER AND CLAMP Filed March 6, 1964 FIG.1 PIC-3.2

11a 8 1211a v 14 15 2. 7 6

(/WZEP Stay L. Eli/(5.5011

United States

Patent

2, 8 7 Claims. (Cl. 29-96) This invention relates to a tool for metal cutting, preferably for use in a copying lathe, comprising a holder, a tip of cemented carbide, high-speed steel, ceramic material or the like detachably mounted on the holder, and

i a unit acting as chip breaker and clamp mounted above the tip, which unit may consist of one or several parts.

In conventional tool constructions of the aforesaid type a great number of different arrangements for stepwise or variable displacement of the chip breaker width are utilized. Most of these' arrangements, however, have the disadvantage in common that the chip breaker width must be re-adjusted every time the tip is turned or exchanged. This invention has, therefore, as its object to produce a tool construction of the aforesaid type wherein a tip can be exchanged or turned without disturbing the chip breaker width adjusted by the machine setter for a certain operation.

The invention is characterized in that the unit acting as chip breaker and clamp is adapted to be clamped detachably to an intermediate portion mounted movably on the holder and adapted to be secured thereto by a lock means, so that the chip breaker width is changed only by displacing the said intermediate portion.

The invention will be described in greater detail in the following, reference being had to the accompanying drawing showing by way of example an embodiment of a tool according to the invention, whereon:

FIG. 1 shows a vertical section through the tool along the line II in FIG. 3,

FIG. 2 shows a vertical section along the line IIII in FIG. 1, and

bFIG. 3 shows a horizontal view of the tool seen from a ove.

The embodiment of the tool according to the drawing comprises a holder 1 whereon a tip 2 is clamped between a support plate or sole 3 fastened to the holder by a screw 4 and a unit acting as chip breaker and clamp, which unit in the embodiment shown comprises a clamping plate 6 with wear protections 7 welded thereon. A lateral clamp iron 5 is provided for rendering additional hold of the tip 2, thereby preventing the tip from being turned or drawn out by the cutting forces. The said clamping plate 6 has a symmetric shape allowing it to be turned when one of the wear protections 7 is worn out, and is adapted to be clamped detachably by a first stop screw 8 to an intermediate portion in the form of a cube 9 disposed movably in an inverted T-groove 10 in holder 1. The said cube 9 can be secured in groove 10 by a second stop screw 11 in that the flanges 9a of said cube (see FIG. 2) upon tightening of screw 11 are pressed against the upper surfaces of said T-groove.

The chip breaker width B is adjusted by first loosening stop screw 8 which is provided with a catch ring or rider 12 for lifting the clamping plate 6. Thereafter stop screw 11 is loosened through one of the two holes 11a, so that the cube 9 together with clamping plate 6 can be displaced in the longitudinal direction of the T-gr0ove for the setting of B. Thereafter stop screw 11 is tightened, whereby the cube 9 is rigidly anchored in T-groove 10. Upon tightening stop screw 8 the tip 2 is secured between the clamping plate 6 and the sole 3, and at the same time the anchoring of cube 9 in T-groove 10 is increased.

It is easy to understand that tip 2 can be exchanged or turned without disturbing the chip breaker width B. One need only loosen stop screw 8 whereby the clamping plate 6 follows along with the screw, due to the rider 12, thus forming an opening between clamping plate 6 and tip 2 whereby the latter is entirely released. By this construction it is even possible to exchange clamping plate 6 when it is worn out, without changing the chip breaker width B.

For additional safety in obtaining accurate setting of the clamping plate 6 after the tip 2 was turned or exchanged, the hole for the stop screw 8 in the clamping plate 6 and/ or the countersink of said hole may be placed such, that upon tightening the screw 8 the clamping plate is not only pressed against the

contact surfaces

13 and 14 on the upper surface of the holder, but also in lateral direction against a support face 15. Hereby it is ensured that the chip breaker edge of the clamping plate 6 always assumes the same angular position in relation to cutting edge 16.

In order to render possible full utilization of the threads of cube 9 and stop screw 8, the bottom of he T-groove 10 is provided with a recess 17.

The clamping plate 6 may also be made without holes 11a. In this case, however, the plate must be lifted off for setting the chip breaker width. Furthermore, both the holder 1 and the cube 9 must be provided in this case with a suitable graduation, because the plate 6 acting as chip breaker is removed during the setting operation.

The invention is not restricted to the embodiment described above, but may be varied within the scope of the following claims. It is, for example, possible to construct the unit acting as chip breaker and clamp in two parts, i.e. with a loose chip breaker clamped between a separate clamp and the tip. It further is possible to arrange an eccentric mechanism or another suitable mechanism for a positive control of the setting movement which in the embodiment shown is effected manually. The above described details may be exchanged against details of equivalent function. The stop screw 11, for example, for clamping the cube 9 can be replaced by another clamping means, such as a jaw means or the like. There are even further modifications imaginable within the scope of the invention. The unit 6, 7, for example, may be made entirely of cemented carbide.

What I claim is:

1. A cutting tool comprising: a tool holder; a prismatic cutting bit mounted detachably on said holder and having cutting edges provided at intersections between the top and bottom surfaces and the side surfaces of the bit; a unit acting as a chip breaker and clamping member for clamping the bit onto said holder and mounted above said bit; an intermediate member adjustably mounted on the holder and arranged between said unit and said holder in the direction of adjustment behind said bit; securing means connecting said unit with said intermediate member for releasably fastening said unit to said intermediate member; and lock means connecting said intermediate member with said holder for releasably clamping said intermediate member into locking abutment with said holder.

2. A cutting tool comprising: a tool holder; a prismatic cutting bit mounted detachably on said holder and having cutting edges provided at intersections between the top and bottom surfaces and the side surfaces of the bit; a unit acting as a chip breaker and clamping member for clamping the bit onto said holder and mounted above said bit; an intermediate member adjustably mounted on the holder and arranged between said unit and said holder 3. A cutting tool comprising: a tool holder; a prismatic cutting bit mounted detachably on said holder and having cutting edges provided at intersections between the top and bottom surfaces and the side surfaces of the bit; a

unit acting as a chip breaker and clamping member for clamping the bit onto said holder and mounted above said bit; an intermediate member adjustably mounted on the holder and arranged between said unit and said holder in the direction of adjustment behind said bit; a set screw connecting said unit with said intermediate member for/ releasably fastening said unit to said intermediate member; a supporting face on said holder for said unit; a bore in said unit, said bore being offset laterally, so that upon tightening said set screw said unit is urged in lateral direction against said supporting face; a supporting face on said holder for said unit; lock means connecting said intermediate member with said holder for releasably clamping said intermediate member into locking abutment with said holder.

4. A cutting tool comprising: a tool holder; a prismatic cutting bit mounted detachably on said holder and having cutting edges provided at intersections between the top and bottom surfaces and the side surfaces of the bit; a unit acting as a chip breaker and clamping member for clamping the bit onto said holder and mounted above said'bit; an intermediate member comprising nut means adjustably mounted on the holder and arranged between said unit and said holder in the direction of adjustment behind said bit; a slot of inverted T-shape in said holder for the adjustment of said nut means; securing means connecting said unit with said nut means for releasably fastening said unit to said nut means; and lock means connecting said nut means with said holder for releasably clamping said nut means to said holder.

5. A cutting tool comprising: a tool holder; a prismatic cutting bit mounted detachably on said holder and having cutting edges provided at intersections between the top and bottom surfaces and the side surfaces of the bit; a unit acting as a chip breaker and clamping member for clamping the bit onto said holder and mounted above said bit; an intermediate member comprising nut means adjustably mounted on the holder and arranged between said unit and said holder in the direction of adjustment behind said bit; a slot of inverted T-shape in said holder for the adjustment of said nut means; securing means connecting said unit with said nut means for releasably fastening said unit to said nut means; a set screw connecting said nut means with said holder adapted upon its tightening to press shoulders of said nut means into locking abutment with corresponding shoulders of said T- shaped slot; and a hole through said unit provided for loosening said set screw without the need for said unit to be lifted off.

6. A cutting tool comprising: a tool holder; a prismatic cutting bit mounted detachably on said holder and having cutting edges provided at intersections between the top and bottom surfaces and the side surfaces of the bit; a unit acting as a chip breaker and clamping member for clamping the bit onto said holder and mounted above said bit; an intermediate member comprising a nut means adjustably mounted on the holder and arranged between said unit and said holder in the direction of adjustment behind said bit; a slot of inverted T-shape in said holder for the adjustment of said nut means, said slot being a through slot; securing means connecting said unit with saidnut means for releasably fastening said unit to said nut means; and lock means connecting said nut means with said holder for releasably clamping said nut means to said holder.

7. A cutting tool comprising: a tool holder; a prismatic cutting bit mounted detachably on said holder and having cutting edges provided at intersections between the top and bottom surfaces and the side surfaces of the bit; a unit acting as a chip breaker and clamping member for clamping the bit onto said holder and mounted above said bit, said unit being turnable so that different surfaces can act as a chip breaker; an intermediate member comprising nut means adjustably mounted on the holder and arranged between said unit and said holder in the direction of adjustment behind said bit; a slot of inverted T-shape in said holder for the adjustment of said nut means; securing means connecting said unit with said nut means for releasably fastening said unit to said nut means.

References Cited by the Examiner UNITED STATES PATENTS 3,113,372 12/1963 Hargreaves 2996 3,124,866 3/1964 Novkov 2996 WILLIAM w. DYER, 1a., Primary Examiner.

HARRISON L. HINSON, Examiner.