US3084432A - Portable hand tool - Google Patents

Description

April 9, 1963 R. E. HILL 3,084,432

PORTABLE HAND TOOL Filed May l, 1961 2 Sheets-Sheet 1 April 9, 1963 R. E. HILL PORTABLE HAND ToorJ 2 Sheets-Sheet 2 Filed May l, 1961 United States This invention relates to a portable hand driven tool of the type having two jaws which are pressed together to operate on a piece of work.

The invention provides a tool actuated by two lever portions swingable relatively to one another in the manner of the handles of a pair of tongs, although one may be quiescent during the operation. The jaws are spread by a simple swinging movement of these levers and closed on the work by a reversal of the movement and, if the resistance encountered is small, the work may be completed as such movement ends. However the tool permits force to be applied to the work after the jaws are engaged by one or more oscillating or pumping strokes with greatly increased mechanical advantage. The change is as it .were automatic, no adjustments or manipulations being required other than simple in and out swinging movements of the operating hand.

My invention will be well understood by reference to the illustrative embodiment thereof shown by way of example in the accompanying drawings wherein:

FIG. l is an elevation of the tool ywith jaws and handles closed;

FIG. 2 is a fragmentary view showing the handles spread wide for application of the jaws to the work;

FIG. 3 is a simple View showing the handles in an intermediate position such as they might occupy when the jaws have closed on the work;

FIG. 4 shows the handles further closed and ready for operation of the tool by an oscillating stroke with increased mechanical advantage; and

FIGS. 5 and 6 are sections respectively on lines 5 5 and 6 6 of FIG. l.

The constructional elements of the invention are ernbodied primarily in the swing levers (one simple and the other complex as will appear) which are grasped by the hands. The jaws and their mountings may be various. Usually the tool will be of the compound lever rather than the single jointed type and the drawings illustrate by way of example a compound lever tool of the type disclosed in the United States patents to Lindsay 146,829 and 147,850.

Referring to FIG. l the tool shown embodies two jaw levers 10 pivoted together in non-crossing relation by plates 12 and operated by two bent levers 14 pivoted to their tails and joined by pivot 16 to provide an operating toggle between them which is straightened to press the jaws together. The other arms of the bent levers become functionally parts of the two handle levers, the left-hand lever 24 which is effectively one piece and the right-hand lever which comprises a distal part 26 and a proximal part 28 pivoted together by transverse pivot pin 30. The words distal and proximal are words of differentiation and here mean relatively far and near respectively to one supporting the tool by its handles in a horizontal plane before him.

TheA tool shown would ordinarily be brought to the MIS work, the jaws applied and closed by movements of both hands, perhaps unequal, and more or less spontaneous and diicult to differentiate. However the left hand might be quiescent and merely maintain the position of handle 24 during the working portion of the jaw closing movement and it might be supported by an available relatively stationary abutment. It will therefore be convenient in the following description to consider lever 24 as stationary as it well might be.

The powerfully operating closing movement of the handles is elected by a flexible band connector such as the sprocket chain 32 xed at one end to handle 24 and which is hauled in by mechanism embodied in handle 26-28 in order to close the tool. This mechanism will next be described.

The distal portion 26 of the right-hand handle is bifurcated at its lower end and receives between the two arms thus formed a sprocket wheel 34 loosely mounted on the pivot pin 30 which traverses these arms. The proximal portion terminates distally in a pair of cheeks 36 enclosing the lower end of the portion 25 and the sprocket wheel. The cheeks are pivoted on pivot 3d and from the-se cheeks extends the main portion of the handle 28 herein shown as formed in part as a tube 3S for a purpose which will appear. The cheeks 'and the proximal handle section of which they form Ia part may swing on pivot 30 relative to section 26 through a limited arc determined by the cooperation of spaced shoulders 40 on the edges of the cheeks with the ends of a pin 42 projecting from the sides of distal handle portion 26. The sprocket chain 32 is wrapped around the sprocket 34 for a relatively short -arc and extends tinto the tube 38 where it is anchored `by a spiral spring 44 which tends to haul in on the chain. When the chain is payed out the spring expands.

The spnocket wheel 34 is utilized in the manner of a windlass `drurn `for hauling rin :on the flexible connector but on account of its positive engagement of its teeth with the chain links only a small angle of wrap is required to effect this drive. Also the teeth serve as ratchets for cooperation with suitable pawls which provide means for selectively clutching the two parts 2a and 28 of the handle to the drum. Herein la feeding pawl 46 is provided pivoted to the cheeks 35 and a detent pawl 4S pivoted on a cross-pin between the lower arms of the handle section 26. The shape lof these pawls and the sprocket teeth and the positions lof the pivots of 'the pawls are such that the sprocket is always free to rotate clockwise viewing the gures, the pawls clattering over the teeth and the part of the chain 32 between the two -arms of the tool in whatever relative position they have is always tensioned by the spring.

Now let as assume the tool in closed position as shown in FIG. l, and that we wish to open the jaws and apply them to the work. The chain is snubbed by the sprocket which is held by pawl 48, which (see FIG. 5) is carried by the lower arms of distal handle section 26 and the proximal portion of the handle turns counterclockwise about --pivot 30 until the movement is checked by pin 42 fetching up against the right handle shoulder 40 with the parts in the position of FIG. 2. `In arriving at that position the lower portion of pawl 46 strikes the dependingA tail of pawl 4S and disengages it. The pawl 48 is rocked and its nose strikes the side of pawl 46 and disengages that pawl as clearly seen in the figure. The sprocket is thus released and the chain pays out freely except as tensioned by ythe spring. A component of pull exerted on the pivot 30 in the spreading movement of the handles rocks distal handle portion 26 on its pivot 50 and opens the jaws of the tool and they may be removed from the work.

When the parts are in the position of FIG. 2 the jaws are open and may be applied to the work. Before the pawls are engaged unless the handles areheld apart the spring 44 will draw on chain 32 and move pivot 3d to the left. This swings distal part 26 about its distal pivot 50 on the jaw tail and moves the right-hand jaw toward the work. Moreover when closing pressure -is applied to the handles a certain amount of thrust longitudinally of the proximal handle section 23 will have a component tending to move pivot 3i? to the left as well as to swing proximal portion 23 clockwise about it and by the time the parts have returned to some such position as in FIG. 3 with the pawls engaged the jaws usually will have made contact with the work and even exerted some substantial pressure on the same.

After the pawls have been thrown in and the parts have a position like that shown in FIG. 3 any motion of pivot 30 toward the -left imparted by the hands (and it must be mot-ion about the pivot 5d on the jaw tail at the elbow at the distal end of section 26) tends to roll sprocket 34 clockwise along the chain like the wheel of a wheelbarrow with the pawls clattering and the axle moves to the left carrying with it the adjacent ends of both sections of the handle. The pressure of the work on the jawsresists movement of the distal section about its upper pivot and ultimately, except when the tool is applied to an occasional operation where the resistance is very low compared to the capacity of the tool, its movement in this manner is checked. But the proximal section may then swing about pivot 30 and the feeding pawl 46 will turn the sprocket and draw on the chain. Initially this may be a barely realized change in the force demand which may be suiiicient to finish the operation. Otherwise the handle is oscillated with one or more repeated pumping strokes. tlf the jaws are of the nipper type, as illustrated, the end is signalled by the cessation of resistance when the work piece parts under tension. Otherwise progress may be judged by the increase in demand, the increased resistance may satisfy the worker that the job is completed, perhaps with one nal stroke for assurance, or in certain cases a predetermined number of pumping actions may be prescribed. `On the other hand as the toggle formed by the arms of the bent levers pivoted atY 16 closely approaches the straight position the mechanical advantage of the lever system increases indetinitely and the resulting decrease in demand will be felt and this provides a criterion for judging the completion of the desired operation. The spring 44 by contracting takes care of the length of chain fed over the sprocket towardl the right during operation of the tool.

It will be apparent that the invention may be embodied in other specic forms without departing from the spirit or essential attributes thereof, and the present embodiment should therefore be considered in all respects as illustrative and not restrictive, as is in fact clear in several matters from the description itself. Reference is to be had to the appended claims to indicate those principles of the invention exemplied by the particular embodiment described and which it is desired to secure by Letters Patent.

I claim:

1. A hand operated tool comprising work-engaging jaws and iirst and second relatively swinging arms connected thereto to approximate and separate the jaws on in and out movements of the arms, the second of the arms comprising a distal part which is connected to one of the jaws and a proximal part connected to the distal part by a transverse pivot about which the two parts may turn, a

sprocket loose on said pivot, a chain connected to the` first"` arm, trained over the sprocket and terminally connected to a take-up spring carried by the said proximal part of the second arm, a detent pawl carried by the distal part and a driving pawl carried by the proximal part, both arranged to permit free rotation of the sprocket in a direction to draw in on the chain, but when engaged with the sprocket teeth to prevent movement in the opposite direction to establish a driving connection from the proximal part through its driving pawl to the sprocket, the pawls being so arranged that extreme outward movement of the proximal part frees both from the sprocket.

2. A tool as set forth in claim 1 wherein the detent pawl is pivoted between its ends and the driving pawl is pivoted at a more distant point from the pivotal center to engage on extreme outward movement of the proximal part with the tail of the detent pawl to disengage that pawl and itself then to be engaged by the nose of the detent pawl so that it itself is disengaged as a result.

3A. A hand operated tool comprising work-engaging jaws and first and second relatively swinging arms connected thereto to approximate `and separate the jaws on in and out movements of the arms, the second of the arms com-v prising a distal part which is connected to one of the jaws and a proximal part `connected to the distal part by' a transverse pivot about which the two parts may turn, a sprocket loose on said pivot, a chain connected to the iirst arm, trained over the sprocket and terminally con-j nected to a take-up spring carried by the said proximal part of the second arm, one-way clutching means on the distal and proximal parts respectively -for engaging them with the sprocket operatively coordinated with the prox-A imal part for release of the sprocket therefrom as a' result of movement of the proximal part to an extreme outward position and to be moved into engagement as a result of the movement of the proximal part to an intermediate position to establish a driving connection from the proximal part to the sprocket.

4. A hand operated tool comprising work-engaging jaws and tirst and second relatively swinging arms connected thereto to approximate and separate the jaws on in and out movements of the arms, the second of the arms comprising a distal part which is connected to one of the jaws and a proximal part connected to the distal part by a transverse pivot about which the two parts may turn, the proximal part providing a handle which may be swung about the pivot toward `and from the first member, a rotary member loosely mounted on said pivot and providing a barrel for engagement with the pulling member hereinafter referred to, a exible pulling member connected to the rst arm, wrapping around said barrel :and terminally connected to a take-up spring carried by said proximal part of the second arm, one way clutching means on the distal and proximal parts which in :all positions permit movement of the barrel in the direction to draw in on the pulling member, Ysaid clutching means including portions carried by the distal and proximal parts respectively for throwing out the clutching means of the other part when the proximal part is turned about the pivot to an extreme outward position away from the first arm and providing yfor their return when the proximal part is brought to an intermediate position thereby to establish a driving connection from the proximal part to the barrel.

5. A hand operated tool comprising work-engaging jaws and first and second relatively swinging arms connected thereto to approximate and separate the jaws ou in 4and out movements of the arms, the second of the yarms comprising a distal part which is connected to one of the jaws and a proximal part connected to the distal part by a transverse pivot about which the two parts may turn, the proximal part providing a handle which may be swung about the pivot toward and from the tirst member, a rotary member loosely mounted on said pivot and providing a barrel for engagement with the pulling member hereinafter referred to, a exible pulling member connected to the lirst arm wrapping around said barrel `and terminally `connected to a take-up spring earried by said proximal part of the second arm, `a ratchet drive for the barrel including a feed pawl on the proximal member which is moved out of operative position as a result of movement of the proximal part to an Iextreme outward position away from the rst arm and returned into such engagement las a result of the return of the proximal part to an intermediate position and a detent 10 2,643,564

pawl carried by the distal part having ratcheting engagement with the barrel which pawl is likewise moved from such engagement as a result of movement of the proximal part to an extreme outward position and returned as a result of the return of the proximal .part to the intermediate position.

References Cited in the le of this patent UNlTED STATES PATENTS Klein etal. June 30, 1953

Claims (1)

1. A HAND OPERATED TOOL COMPRISING WORK-ENGAGING JAWS AND FIRST AND SECOND RELATIVELY SWINGING ARMS CONNECTED THERETO TO APPROXIMATE AND SEPARATE THE JAWS ON IN AND OUT MOVEMENTS OF THE ARMS, THE SECOND OF THE ARMS COMPRISING A DISTAL PART WHICH IS CONNECTED TO ONE OF THE JAWS AND A PROXIMAL PART CONNECTED TO THE DISTAL PART BY A TRANSVERSE PIVOT ABOUT WHICH THE TWO PARTS MAY TURN, A SPROCKET LOOSE ON SAID PIVOT, A CHAIN CONNECTED TO THE FIRST ARM, TRAINED OVER THE SPROCKET AND TERMINALLY CONNECTED TO A TAKE-UP SPRING CARRIED BY THE SAID PROXIMAL PART OF THE SECOND ARM, A DETENT PAWL CARRIED BY THE DISTAL PART AND A DRIVING PAWL CARRIED BY THE PROXIMAL PART, BOTH ARRANGED TO PERMIT FREE ROTATION OF THE SPROCKET IN A DIRECTION TO DRAW IN ON THE CHAIN, BUT WHEN ENGAGED WITH THE SPROCKET TEETH TO PREVENT MOVEMENT IN THE OPPOSITE DIRECTION TO ESTABLISH A DRIVING CONNECTION FROM THE PROXIMAL PART THROUGH ITS DRIVING PAWL TO THE SPROCKET, THE PAWLS BEING SO ARRANGED THAT EXTREME OUTWARD MOVEMENT OF THE PROXIMAL PART FREES BOTH FROM THE SPROCKET.

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