US2274945A - Pliers - Google Patents

Description

March 3, 1942. H. P. VAN KEUREN 2,274,945

PLIIERS' 3 Sheets-Sheet 1 Filed July 19, 1939 INVENTOR H. P. VAN KEUREN I March ,3, 1942.

' I PLIERS Filed July 19, 1959 s Sheets-Sheet 2 INVENTOR March 3, 1942. VAN KEUREN 2,274,945

PLIERS Filed July 19, 1939 s Sheets-Sheet s INVENTOR Patented Mar. 3, 1942- PLIERS v Henry P. Van Keuren, Watertown, Mesa; Marie 8. Van Keuren administratrlx of said Henry P. Van Keuren, deceased Application July 19, 1939, Serial No. 285,346

7 Claims.

This invention relates to pliers and to other hand tools of the leverage class. The object is to provide increased power primarily for cutting purposes.

The invention comprises arrangements of operating levers, cooperating fulcrums and cutters in such relation to one another that it is possible to cut wire, etc., nearer the center of the leverage system, thereby increasing the power and capacity of a given size of tool.

Referring to the drawings which illustrate examples of several embodiments of my invention- Fig. 1 shows the'adaptation of my invention to a handy size of inexpensive forged combination pliers such as are in general use.

Fig. 2 is a top view of the same.

Fig. 3 is a view of the pliers with jaws open.

Fig. l shows the jaw end oi a larger pair of pliers of different detailed construction.

Figs. 5, 6, 7, and 8 show various details of the closed. of Fig. 15 to show alternate construction i for either type of cutter.

The pliers shown in Fig. 1 comprise two dropforged steel lever elements I embodying suitably formed and hardened gripping and cutting jaws at the one end and suitably shaped handles at the other. The said lever elements I are identical parts and are adapted to mate with each other in reversal about a longitudinal axis in such manner as to form a pair of crossed levers having an approximate imaginary pivotal fulcrum at 0 thus providing a jaw portion for each of said levers on the opposite side of the longitudinal axis and at the opposite end from the handle portion in the customary way. The usual single 4 pivot or fulcrum would lie at point 0. In my invention, however, I substitute, for the usual and customary single pivotal fulcrum, two fulcrum pins 2 equidistant, in this case, from point 0. Each of said pins 2 is fixed in one lever element l but rides or slides in a close fitting accurately cut slot 4 in the mating lever element I. The said slots, in this-case, lie on the jaw side of point 0 and converge toward the nose or the pliers. Since elements I are identical parts. said slots are symmetrically disposed about the longitudinal axis and the perpendicular bisectors of each slot meet at point 0 whether the slots are straight or uniformly curved about said point d. An opening or closingmovement of the handle portions of lever elements i results in opposite rotative motion of said elements about an approximate center li caused by the simultaneous sliding of each pin 2 in the cooperating slot t of the mating element i In the case of Fig. 1, pins 2 slide or move toward the nose of the pliers as shown by the arrows, when the jaws are opened and move toward the handles when the jaws are closed, as shown by the arrows in Fig. 3.

By means of the slidable pin and slot arrangement each of the crossed levers it is movably iulcrumed to the other lever I and although the resultant motion at each instant is amotion of rotation about a iulcral center ii at said crossing, yet said center is unobstructed and tree of any pivotal connection of one lever to the other at this point, hence the cutters or shearing edges may be extended substantially to or everuto said center. Extending the cutters toward or to the pivotal center of rotation or fulcrum it of lever elements It enables a wire W to be out very near to the fulcrum, if slippage is prevented. Consequently, any reduction in the length of the short end of the lever is accompanied by a correspond ing increase in the power of the tool in accordance with the well-known law of the lever.

In Fig. 1 it may be pointed out that each or pins 2 is fixed in a thumb-like extension on the opposite side of the longitudinal axis from the jaw portion of element i hence each pin rotates about point 0 in the same relative direction as the jaw and handle to which it is fixed, or counter-clockwise for the upper pin and clockwise for the lower, the resultant motion of the two pins being that of simultaneous convergence toward the nose of pliers upon opening the jaws.

In Fig. 4, the pins 6 are each fixed on the same side of the longitudinal axis as their respective laws while slots '1 are located in the thumb-like extension of elements 5 and 5A. The resultant motion of pins 5 in this case is exactly the reverse of the motion of pins 2 in Figs. 1 and 3 as shown also by the arrows.

Due to the sliding action of the pins in their slots both pins and slots should be accurately formed and hardened to minimize both wear and play and give extended service.

Figs. 5 and 6 show a method of employing hardened pins whereby they can readily be as- 55 sembled in rapid' production. Pin 2 is hardened and ground in the central portion and embodies a grooved or necked down stud at each end. Un-

hardened dished washers or collars are held at their periphery against expanding by means of a against abutment portions ll of the laws is provided to relievescrews 9 of a portion of the cutting loads. Said cutters 8 are stamped from flat stock and hardened. They are provided with bevelled cutting edges of the so called nlppertype as shown by the sectional view, Fig. 8. Recesses I allow insulated wire of reasonable size to be cut without crushing. Bare wire W of large size requiring more power to cut is held and sheared in the V shaped wire-holding throats N which are provided with substantially 90 degree shearing edges'on the jaw side of said notches. A considerable advantage results from the useof said V shaped throats N. The wire or rod to be cut is inserted as far as it will go and is thus supported on both upper and lower surfaces and is squarely held while being sheared off. Customarily the wire is either unsupported at the top or is carried in a slot having parallel sides spaced farther apart than the diameter of the wire.

When subjected to the shearing action of the throat N by extension of the recesses l0 substantially to point 0. The use of cutting blades 8a provides side cutters extending nearly to center 0 of the leverage system.

' Figs. 9, 10, and 11 show pliers composed of two identical stamped sheet metal lever members l provided with siidable fulcrum pins ll engaging slots 18, each member being.provided with a pin l'l fixed in the thumblike portion on the opposite side of the axis from the jaw portion which is provided with slot 08.. Offsets. l6 permit the reversal of said members I5 one with respect to the other so that pins 11 each engage slots [8 and are simultaneously siidable therein in the directions shown by the arrows. Handle portions of members l5 are stamped 'in a U shaped'form as shown by Fig. 12 which is a section on line \l2. as shown. The law portion of members I5 is bifurcated and one side only of each member is offset as at 16 to pass over the straight portion of the opposite jaw. Removable, replaceable. identical cutters ll provided with bevelled cuttinged'ges as shown in Figs. 13' and 14 are located between said bevelled cutting edges align with each other on the median plane of the tool.

the other end for enga ement with screw l9.

Noting that in pliers of this form the slidable fulcrum pinsl'l lie on the handlewards side of center 0, it is apparent that cutters H are moved well apart from engagement with each other at the handleward end by means of the fulcrum pins l1 and at the nose or slotted end by means of screws l9 during opening of the jaws. Thus a clear throat opening even beyond center 0 is provided and wire may be out exactly on the center of the leverage system with small effort as compared to the ordinary types of pliers. It should be further noted that there is a decided drawing action in this type of cutter-the amount of draw of the wire into the throat of the cutter being substantially equal to the length of slot in the cutter if the full motion from wide open jaw to closed jaw is used. This drawing action renders cutting easier because the cutting edges are rocking with respect to their work and the instantaneous length of cut is reduced thereby. Further, the wire is being moved toward the center while being out. Also, the angle between the cutters in wide open position may be kept under about 24 degrees to insure against slippage at the start of the cut yet a wire or piece of relatively largediameter may be readily engaged and cut on center 0.

A hardened T shaped nosepiece 2| serves also as a spacer and filler between the bifurcated jaw portions of each member l5 and is secured thereto by means of rivets 22 or by spot welding.

The construction of these pressed steel pliers as shown herein permits the manufacture of extremely powerful, light cutting pliers at such a low production cost that retail prices may be kept well down and wide distribution assured. To the user of pliers the feature of inexpensive renewable cutting blades will have instant appeal.

Fig. 15 shows the application of my invention to low priced drop forged steel pliers having nipper type cutting edges located either in the center of the tool as shown by Fig. 16 or at the side of the jaws as shown by Fig. 17. In Fig. 15 it is apparent that the center of rotation 0 is toward the Jaws from pins 24 and slots 25 located in lever elements 23 as hereinbefore described. In the wide open Jaw position cutters 26 meet at center 0 and a wire may be introduced between said cutters as far as its diameter will permit and vented, with remarkable ease.

I have herein shown symmetrical arrangements of pins and slots in this new leverage system. In

some cases the pins lie on the jaw side of the center and in other cases on the handle side. When the slots are straight the resultant motion is a combination of rotation and translation; when the slots are uniformly curved about the center the resultant motion is pure rotation.

- Many combinations and even unsymmetrical.

arrangements of pins siidable in cam-slots are possible giving great-variety of motion and I have constructed several models of pliers having unsymmetrical arrangements and motions. Little is gained in most of these combinations and in it engages a fulcrum pin II at the one end and is provided with a slot 20 at all of them wherein the locations of pins and slots are difierent in each member the cost of manufacture is increased thereby. To avoid rangement wherein the perpendicular blsector of the two slots coincide on a line at right angles to the longitudinal axis, said line passing through the center of rotation of the lever elements in the closed jaw position.

operating lever elements embodying .opposed jaws on one side of the crossing and actuating handles on the other anddual movable fulcrum means of cooperation between said lever elements said means consisting of two pin members laterally and oppositely disposed at said crossing with respect to a center of motion therein each of said pin members being respectivelyfixed in a portion of one of said lever elements and being slidably movable in an adjacent respective portion of the other said lever element whereby the said center of motion is unobstructed by any pivotal connec tion between said lever elements.

2. Cutting pliers embodying two cooperating levers having jawsand handles at opposite ends thereof, fulcrum means of cooperation between said jaws and handles consisting of a joint comprising pins and slots spaced apart from the center of said joint and cutting means on said jaws consisting of cooperating throats tapering .toward the center of said joint each said throat having a shearing edge on one side thereof and a supporting edge opposite thereto.

3. Pliers comprising two rotatably crossed levers having jaws at one end and handles at the other, means of opposite cooperative rotation between said levers, said means consisting of two slidable fulcral members oppositely spacedapar't from the center of rotation of said levers and rearwardly thereof and two separate opposed cutting members each being movably secured to a jaw respectively at the forward end and to a fulcral element respectively at the rearward end of said cutting member.

4.. Pliers comprising two crossed levers having renewable cutters at one side of the crossing and actuating handles at the other, fulcrum means of cooperation between said cutters and handles, said means consisting of a rotatable joint having a center at said crossing to which said cutters are rearwardly extended and securing means for said joint comprising two movable headed pin members extending through both levers at said crossing said pin members being oppositely spaced apart from the center of said joint.

5. In a cutting tool embodying a pair of levers having rotatable fulcral means of connection therebetween, opposedly cooperating cutting means on said levers extending to the center of rotation thereof.

6. A tool embodying a pair of rotatably crossed levers, a connecting fulcrum joint therefor at the crossing thereof and opposedly cooperating cutters on said levers extending to the center of said joint.

7. In a tool embodying a pair of lever elements a connecting joint therebetween, said joint consisting of a pair of fulcrums spaced apart from the center of motion of said elements each said fulcrum being fixed respective to one said element and being slidable with respect to the other said element.

HENRY P. VAN KEUREN.

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