US2938266A

US2938266A - Oblique cutting plier

Info

Publication number: US2938266A
Application number: US810146A
Authority: US
Inventors: Jr Mathias A Klein
Original assignee: Mathias Klein & Sons
Current assignee: Mathias Klein & Sons
Priority date: 1959-04-30
Filing date: 1959-04-30
Publication date: 1960-05-31
Anticipated expiration: 1977-05-31

Description

y 31, 1960 M. A. KLEIN, JR 2,938,266

OBLIQUE CUTTING PLIER Filed April 30 1959 mung;

54 INVENTOR.

United States Patent C) F 2,938,266 OBLIQUE CUTTING PLIER Mathias A. Klein, Jr., Wilmette, Ill., assignor to Mathias Klein 8: Sons, Chicago, 11]., a corporation of Illinois Filed Apr. 30, 1959, Ser. No. 810,146

2 Claims. (Cl. 30-124 The present invention relates to oblique cutting pliers and more particularly to an oblique cutting plier which has the ability to catch and hold the clipped end of a cut wire.

It is the principal object of the present invention to provide a novel oblique cutting plier having all of the advantages ordinarily associated with cutting pliers of this type and which reliably catches and holds the clipped end of a wire so that the clipping may be removed with the tool.

An additional object is to provide a novel plier having the above characteristics and which, in addition, is so constructed and arranged that the plier does not have overhanging or outwardly projecting elements which may catch on other objects or which are unsightly or easily broken, or which give the impression that the plier has accessory equipment attached thereto or is otherwise unconventional.

Yet another object is to accomplish the above in a tool having a long useful life.

Other objects and advantages will become apparent from the following description of a preferred embodiment of my invention which is illustrated in the accompanying drawings.

In the drawings, in which similar characters of reference refer to similar parts throughout the several views,

Fig. 1 is a side view of the improved plier in open position;

Fig. 2 is an edge view thereof in closed position;

Fig. 3 is an enlarged longitudinal medial sectional view of the head of the plier and may be considered as taken in the direction of the arrows substantially along the line 3-3 of Fig. 2;

Fig. 4 is a longitudinal medial sectional view of the head of the plier which may be considered as taken in the direction of the arrows substantially along the line 4-4 of Fig. 3;

Fig. 5 is an end view of the open jaws of the plier; and

Fig. 6 is a longitudinal medial sectional view of the head of the plier, similar to Fig. 3, but showing the jaws in closed position with a clipped piece of wire clamped for removal with the tool.

In the performance of much electrical wiring, particularly of electronic equipment, switchboards and the like, there is a need to cut off and remove the ends of wires from terminals, or to cut wires to length in close quarters under conditions where it is a great advantage to-have the cut end of the wire held by the cutting pliers so that it is easily removed and so that it does not fly off, after being cut, into locations where it is difficult to find.

Special purpose shear cutting pliers, such as those forming the subject matter of my copending United States patent application Serial No. 764,095, filed September 29, 1958, for Long Nose Flush Cutting Pliers have been made for this purpose, and are very elfective excepting under conditions where shear cutting pliers are not as satisfactory as compression oblique cutting pliers.

Patented May 31, 1960.

As examples, stranded wire or very fine wire, or wire with most types of insulation is better cut with oblique cutting pliers than with pliers which cut with a shearing action. v

Pliers or shears have also been proposed with attachments or with accessory members which project to one side for holding cut articles, such as flower stems for instance, but such accessory members are easily broken or would be readily caught, for instance by the wiring forming the circuitry of an electronic chassis, and therefore are of limited utility.

The pliers of the present invention are of the oblique compression cutting type (the cutting knives are in alignment and meet edge-to-edge) and do not have any projecting accessories or clamping members which extend beyond the conventional external limits of the tool itself. There is, therefore, nothing about the tool that is likely to become fouled in close quarters, or in rags, or that is easily broken. In fact the tool, upon casual inspection, does not appear appreciably different from conventional oblique cutting pliers.

As shown in the drawings, the pliers comprise. a pair of

crossed levers

10 and 12 having bow handles 14 and 16 at one end and cutting

jaws

18 and 20 at the other. These levers are pivoted together about a screw 22 so as to have a pivoting axis indicated by the dot 24. Conveniently, a coil spring 26 may have its ends seated in sockets 28 in the adjacent sides of the levers near the pivot on the side toward the handles for the purpose of urging the plier toward open position. This spring may not be needed for this purpose in some embodiments or for some uses, however, since the pliers have other means which normally tend to open them, as will appear presently.

The jaws of the plier have substantially the usual oblique cutting form excepting that the thickness of the nose end of the plier is slightly greater than with most pliers of the oblique type. In the embodiment illustrated, this thickness is about one-eighth inch. As is customary, the outside faces of the jaws are fiat or slightly curved convexly and are oblique to the centerline of the plier. The jaws mutually engage at knife edges 30, and inside these edges the jaws slope away to the opposite side of the plier so as to form outwardly and rearwardly tapered shoulders 32. Because of the wedging action produced by such jaws during a cutting operation, the wire is efliciently cut, but the clipped end tends to fly away uncontrollably.

As shown, the head of the plier is so constructed that the two levers mutually engage at flat, substantially circular, surfaces 34 and 36, these surfaces being normal to the pivoting axis. The pivot screw 22 has a relatively large frustoconical head 38 and a cylindrical portion 40 extending downwardly therefrom. The head and the cylindrical extension fit through a hole in the lever 12 the outer portion of which is complementary to the tapered head 38, so that when the tapered head is seated in the lever 12, the shoulder 42 at the lower end of the extension 40 extends just beyond the inner surface of the flat circular face 36.

A screw threaded portion 44 of smaller diameter than the cylindrical portion 40 extends beyond the shoulder 42 and is threaded into the other lever 10. When this screw is tightened, the shoulder 42 bottoms against the ace-ease is connected to the outside by a sector slot 48. One edge of this sector slot is substantially parallel to the knife edge of the jaw 18 and is olfset with respect thereto so that it falls slightly outwardly of the line of the knife edge. The other edge of the sector slot slants toward the other jaw 20 at an angle of about 45.

The lever 12 as thus relieved around the pivot screw accommodates a leaf spring 50 having a central circular bight 52 which, fits within the recess 46. From this central portion a pair of fingers 54 extend straight outwardly through the sector slot 48 until they strike against the tapered shoulders 32 just inside the knife edges. From this position the spring fingers follow the oblique angle of the knives outwardly to the nose of the tool as is best seen in Fig. 4.

This spring member 50 is bent to bias the fingers 54 away from each other so that in the free position these fingers have an angularity of about 45. For this purpose spring steel about wide by about .025" thick is satisfactory. Because of the spring action, the fingers 54 rest just inside the knife edges and tend to urge the plier jaws apart in the same manner as does the spring 26. It is for this reason that it was previously mentioned that in some instances the spring 26 may not be necessary in order to give the. pliers a self opening characteristic, the leaf spring 50 suflicing for this purpose.

As the plier jaws are closed, the fingers 54 maintain about the same position relative to the knife edges in all positions and this position preferably is such that the contiguous surfaces of the fingers 54 are slightly closer together than are the knife edges. Thus, whenever the plier is closed upon a wire, such as at 60 in Fig. 6, the spring fingers 54 first contact the wire and, as the plier knives advance into the wire, the spring fingers are wedged outwardly away from each other and rearwardly with respect to the knife edges along the tapered jaw surfaces 32, sliding slightly longitudinally with respect to the wire, if necessary, during the cutting action.

When the wire is severed, the fingers 54 maintain their tightgrasp upon the wire clipping until the grip upon the handles is relaxed so as to permit the jaws to open. As soon as this happens, the fingers 54 automatically separate and drop the clipping.

From the above description and from the drawings it is apparent that not only do the pliers accomplish the purpose desired, but that additionally no portion of the wire grasping mechanism projects away from the surface of the pliers where it might become fouled with other tools, rags, wiring, or the like. This feature is most easily observed in Fig. 2.

A screw pivot 22 is shown in place of the usual rivet, because there is a possibility that the spring member 50 may eventually become broken or worn and need replacing and, with a screw pivot, this is easily and quickly accomplished. Furthermore, the optimum heat treatment for the spring member is different from that for the levers and pivot, and it is, therefore, better to assemble the plier after heat treating the separate elements. The screw may be prevented from inadvertently loosening by a punch mark at the thread line between the screw threads 44 and the outside face of the lever 10. Optionally, .a cement may be applied to the screw threads at the time of assembly.

From the above description of a preferred embodiment of my invention it will be appreciated that variations in the structure shown and described may be made without departing from the scope or spirit of the invention and that the scope of the invention, therefore, is to be determined from the scope of the following claims.

Having described my invention, what I claim as new and useful and desire to secure by Letters Patent of the United States is:

1. An oblique cutting plier comprising a pair of crossed levers, a pivot connecting said levers for swinging movement about a common axis, said levers providing two opposed handles extending in one direction from the pivot and two cutting jaws extending from the pivot in the opposite direction, said cutting jaws having a pair of opposed knife edges with opposed tapered shoulders extending outwardly and rearwardly away from said knife edges on the same side of the plier, said levers having a pair of flat faces which mutually engage in the region adjacent the pivot, said pivot being fixed in one of said levers and extending rotatably through the second of said levers, said second lever having a clearance space around said pivot and a slot radiating outwardly from said spacein the direction of said knife edges, said clearance space and said slot being formed as a recess in the flat face of said second lever, a spring member extending around said pivot in said clearancespace and outwardly through said slot and providing a pair of fingers bearing against said opposed tapered shoulders at positions adjacent said knife edges, said fingers being shaped to substantially parallel said knife edges for a substantial portion of the length of said knife edges, said spring member normally biasing said fingers apart, and said slot having a width sufficient to permit said fingers to follow said knife edges as said plier jaws are moved between closed and open positions.

2. An oblique cutting plier comprising a pair of crossed levers, a pivot connecting said levers for swinging movement about a common axis, said levers providing a pair of opposed handles and a pair of cutting jaws, said cutting jaws having a pair of opposed knife edges with opposed tapered shoulders extending outwardly and rearwardly away from said knife edges on the same side of the plier, said levers having a pair of fiat faces which mutually engage in the region adjacent the pivot, one of said levers having a clearance space around said pivot and a slot radiating outwardly from said space in a direction of said knife edges, said clearance space and said slot being formed as a recess in the flat face of the last said lever, a spring member extending around said pivot in said clearance space and outwardly through said slot and providing a pair of fingers bearing against said opposed tapered shoulders at positions adjacent said knife edges, said fingers being shaped to substantially parallel said knife edges for a substantial portion of the length of said knife edges, said spring member normally biasing said fingers apart, and said slot having a width with cient to permit said fingers to follow said knife edges as said plier jaws are moved between closed and open positions.

References Cited in the file of this patent UNITED STATES PATENTS 253,252 Badia Feb. 7, 1882 1,487,808 Rowen Mar. 25, 1924 2,553,697 Zacrep May 22, i