US3408721A

US3408721A - Pin-type toolholder

Info

Publication number: US3408721A
Application number: US699965A
Authority: US
Inventors: Jr Robert W Berry
Original assignee: Fansteel Inc
Current assignee: Fansteel Inc
Priority date: 1968-01-23
Filing date: 1968-01-23
Publication date: 1968-11-05
Anticipated expiration: 1985-11-05

Description

Nov. 5, 1968 R, w. BERRY, JR

PIN-TYPE TOOLHOLDER Filed Jan. 23, 1968 F`IG.3

ATTORNEYS United States Patent O 3,408,721 PIN-TYPE TOOLHOLDER Robert W. Berry, Jr., Ferndale, Mich., assignor to Fansteel Inc., a corporation of New York Filed Jan. 23, 1968, Ser. No. 699,965 6 Claims. (Cl. 29--96) ABSTRACT F THE DISCLOSURE This invention relates to improvements in pin-type toolholders which are used to hold indexable carbide inserts which contain a plurality of single point cutting edges. The applicants device protects the main body of the toolholder from the abrasive effects of the carbide insert and the component parts, which are subjected to the carbides abrasive effects, are designed to be readily replaced at a low cost. The disclosed device has a low manufacturing cost and a low maintenance or service cost.

Background of the invention This invention relates to improvements in toolholders of the type used to hold indexable throwaway carbide inserts. In brief, this invention is an improved version of a pin-type toolholder in which the carbide insert is clamped to the holder by a clamp rack which forces the insert into contact with the pin and an insert seat.

Representative prior art devices known to the applicant are the :following U.S. patents: Milewski 3,176,677, Apr. 6, 1965; Copeland 3,192,602, July 6, 1965; Greenleaf 3,192,603, July 6, 1965; to disclose the general concept of forcing the insert into contact with some sort of a pin.

The invention disclosed in this application differs from the prior art devices by purposely providing a structure which isolates the main body of the toolholder from the abrasive effects of the carbide tool insert. The component parts of the toolholder assembly which are subjected to abrasive wear are designed so that they are disposable and can be readily replaced. The toolholder structure disclosed in this application has been developed with an eye to both the original manufacturing cost and the subsequent maintenance expenses. 'Ihe disclosed structure provides a toolholder with low initial cost, a lengthened useful life span due to the compensation for the abrasive qualities of the carbide inserts, and a low maintenance cost due to the disposable and readily replaceable nature of its component parts.

Description of the invention This invention relates to an indexable toolholder and more particularly to the type of toolholder wherein a throwaway insert of tungsten carbide having a plurality 0f single point cutting surfaces is utilized.

In the prior art devices there is a problem in providing a means of clamping the carbide insert to the toolholder so that it is not subjected to wear due to the abrasive characteristics of the tungsten carbide. Accordingly, a principal object of this invention is to provide a toolholder in which the wear due to abrasion of the clamping means is minimized.

Another object of this invention is to provide a toolholder in which the various components of the clamping means that are subjected to abrasive wear can be readily replaced at minimal cost.

Another object of this invention is to provide a toolholder of the simplified design containing a minimum number of component parts so that it can be readily manufactured and assembled at reduced cost.

Other objects and features of this invention will be apparent from the following description and claims in which there is found the manner of making and using the Fice invention and the best mode contemplated by the inventor for carrying out the invention.

Drawings accompany this disclosure and the various views thereof may be briefly described as:

FIGURE 1, a plan view of a pin-type toolholder.

FIGURE 2, a side elevational view of one embodiment of a pin-type toolholder.

FIGURE 3, a side elevational view of a second embodiment of a pin-type toolholder.

FIGURE 4, a side elevational view of a third embodiment of a pin-type toolholder.

Referring to the drawings:

In FIGURES 1 and 2, a tungsten carbide insert 10 containing a counterbore is shown clamped in the toolholder body 12. A tool seat sometimes referred to as an anvil 14 is retained on a seat area 17 of the body 12 by a shoulder 16 of clamp pin 18 which is pressed into opening 20 in the body 12.

The carbide insert 10 contains an opening 22 which slidably engages a portion 24 of the clamp-pin 18. The carbide insert 10 is firmly held in place on the seat 14 and the clamp pin 18 by the forces created by the clamp rack 26. The clamp rack 26 contains a plurality of serrations forming parallel cam surfaces 28 which co-act with mating cam surfaces on serrations 30 in the body 12. As shown in FIGURE 2, the clamp rack moves laterally relative to the surfaces 30 toward the clamp pin 18 and also axially downward toward the seat 14 when the control screw 32 is threaded into the main body 12. The clamp rack 26 contains an elongated opening 33 which allows it to move laterally relative to the screw 32. The clamping action provided by the clamp rack 26 and the screw 32 tends to force the carbide insert 10 into engagement with the seat 14 and also towards the left (as shown in FIGURE 2) into engagement with the clamp pin 18, thereby securing the carbide insert 10 to the toolholder body 12. 4

It is important that the knife edges 34 of the serrations 28 and the knife edges 36 of the serrations 30 do not contact or bear on each other. If the knife edges 34, 36 contact each other, the stability and effectiveness of the clamp rack 26 is impaired because it rides on its knife edges 34 rather than bearing on the carbide insert 10 and the serrations 30 in the main body 12.

In FIGURE 3 an alternate toolholder construction is shown in which there are two clamp racks 26, one of which bears on the carbide insert 10 and the other of which bears on the seat 14. interposed between the clamp racks 26 is an actuator rack 38, which bears on shoulder area 40 which is substantially perpendicular to the seat area 17 of the toolholder containing two sets of serrations forming cam surfaces 42 which engage the surfaces 28 on the clamp racks 26. This design -provides a positive means of locking both the seat 14 and the carbide insert 10 to the toolholder body 12. It also provides a design in which it is not necessary to cut serrations in the body 12 and in which the component parts containing the cam surfaces can be readily replaced if they become Worn. Furthermore, the head of the toolholder body 12 in this `design is extremely simple to manufacture because it only contains a machined seat area 17, a shoulder area 40, and two

openings

20, 44 for the locking pin 18 and the locking screw 32.

A third alternate design of the toolholder is shown in FIGURE 4 in which a removable actuator rack 46 bears on the shoulder area 40 and contains serrations 48 which co-act with the serrations 28 of the clamp rack 26 in clamping the carbide insert 10 to the seat 14 and the locking pin 18. This design utilizes the simplified clamping structure of the toolholder disclosed in FIGURE 2, but it also provides a disposable actuator rack 46 which can be removed if the serrations 48 become worn. To

reduce the cost of manufacturing this embodiment of the toolholder, the configuration of the clamp rack 26 can be identical to that of the actuator rack 46 so that they are interchangeable with each other.

The abrasive carbide insert does not directly bear on the toolholder body 12 in any of the embodiments of this invention. Furthermore, the rotation of the carbide insert 10 relative to the lock pin 18 and the seat 14 only occurs when the carbide inse-rt 10 is indexed; therefore, the wear due to the abrasive action of the carbide on the seat 14 and the lock pin 18 is minimized. Since the carbide insert 10 does not bear directly on the -main body 12, the wearing away of the clamping means due to the abrasive action of the carbide only occurs on the seat 14, lock pin 18, and clamp rack 26, all of which are disposable or readily replaceable components of the toolholder. Furthermore, it is only necessary to heat treat these three disposable components rather than the entire toolholder body 12. All of these factors contribute to a toolholder of low initial cost which has a minimal repair or maintenance expense.

Thus, it will be noted that in the present application with a stationary pin holding the insert there is no abrasive action resulting from the rotation of the pin, thus preserving the insert from wear at this point and preserving the pin from wear due to the rotation. In addition, there is no shifting of the insert Irelative to the body when a tightening action occurs and thus the wear on the body is completely eliminated and the wear on the clamp block 26 is minimal.

It will also be noted that the clamp block is cammed outwardly by a plurality of cam surfaces on the serrations which provides a stabilizing effect for the block itself and also insures an adequate forward force since the serrations are not intended to seat relative to each other but simply interlock and cam relative to each other. Also, it will be noted that in FIGURE 3 the top cam block 26 as well as the lower block are each urged outwardly so that both the insert 10 and the seat 14 are stabilized relative to the body by being in a camming relationship with the central actuator rack 38 which is backed solidly against the toolholder body.

What is claimed as new is as follows:

1. A toolholder which comprises:

(a) a main body containing a seat area,

(b) a lock pin located substantially perpendicular to the seat area, and

(c) a biasing means adjacent said seat area positioned to contact an insert at said seat having cam surfaces to interengage with multiple cam surfaces on said main body,

whereby a cutting insert which is placed over the lock pin can be clamped in the toolholder by being urged into contact with the lock pin and the seat area by said cam surfaces.

2. A device as defined in claim 1 in which the biasing means comprises:

(a) a plu-rality of parallel cam surfaces which are an integral part of the main body,

(b) a clamp rack containing a plurality of cam surfaces positioned to co-act with the surfaces of the main body, and

(c) a means of urging the cam surfaces of the clamp rack into camming engagement with the cam surfaces of the main body,

whereby the clamp rack is displaced both laterally and longitudinally relative to the main body.

3. A device as defined in claim 1 in which the biasing means comprises:

(a) a first clamp rack containing a plurality of parallel cam surfaces,

(b) a second clamp rack containing a plurality of cam surfaces,

(c) an actuating rack interposed between the first and second clamp racks which contains a first plurality of cam surfaces positioned to co-act with the cam surfaces of the first clamp rack and a second plurality of cam surfaces positioned to co-act with the plurality of cam surfaces of the second clamp rack, and

(d) a means of urging the cam surfaces of the actuator rack, first clamp rack, and second clamp rack into engagement with each other,

whereby both the iirst and second clamp racks are displaced laterally relative to the actuation rack.

4. A device as defined in claim 1 in which the biasing means comprises:

(a) a clamp rack containing a plurality of cam surfaces,

(b) an actuator rack containing a plurality of cam surfaces positioned to co-act with the cam surfaces of the clamp rack, and

(c) a means of urging the cam surfaces of the actuator rack into engagement with the cam surfaces of the clamp rack,

whereby the clamp rack is displaced laterally relative to the actuator rack.

5. A device as defined in claim 1 in which the biasing means comprises:

(a) a tool seat on said seat area,

(b) a rst clamp rack containing a plurality of parallel cam surfaces positioned to contact said tool seat, (c) a second clamp rack containing a plurality of cam surfaces positioned to contact an insert on said seat,

(d) an actuating rack in contact with said body interposed between the rst and second clamp racks which contains a irst plurality of cam surfaces positioned to co-act with the cam surfaces of the lirst clamp rack and a second plurality of cam surfaces positioned to co-act with the plurality of cam surfaces of the second clamp rack, and

(e) a means of urging the cam surfaces of the actuator rack, first clamp rack, and second clamp rack into engagement with each other,

whereby both the first and second clamp racks are displaced laterally relative to the `actuation rack.

6. A toolholder which comprises:

(a) a main body containing a seat area and a shoulder area substantially perpendicular thereto and containing an opening through the seat area,

(b) a tool seat containing an opening,

(c) a lock pin located substantially perpendicular to the seat area and secured in the opening through the seat area the pin passing through the opening in the tool seat,

(d) a biasing means positioned adjacent the seat area in a position to contact an insert at said seat area containing at least two sets of interengaging cam surfaces, and

(e) an actuator means for urging the cam surfaces into camming relation with each other,

whereby a cutting insert which is placed over the lock pin can be clamped to the toolholder by being urged into contact with the lock pin and the tool seat by the actuator means and the biasing means.

References Cited UNITED STATES PATENTS 3,176,377 4/ 1965 Milewski 29--96 3,192,602 7/ 1965 Copeland 29-96 3,192,603 7/ 1965 Greenleaf 29-96 HARRISON L. HINSON, Primary Examiner.