US893071A - Metal-working tool. - Google Patents

Description

Y PATBNTED JULY 14, 1908.

A. L. GODDARD. METAL'WORKING TOOL.

APPLICATION FILED NOV. 2, 1907.

7 WITNESSES. l/VI/E/VTOR ATTORNEY ARTHUR L. GODDARD, OF ROCKFORD, ILLINOIS.

' METAL-WORKING 'rooL.

Specification of Letters Patent.

Patented July 14, 1908.

Application filed November 2, 1907. Serial No. 400,349.

To all whom it may concern:

Be it known that I, ARTHUR L. GODDARD, citizen of the United States, and resident of Rockford, county of Winnebago, Illinois, have invented certain new and useful Improvements in Metal-Working Tools, of which the following is a specification.

This invention relates to metal workin tools and as herein shown and described is applied to a metal working punch.

The invention has for its object to produce asimple and effective punch in which the ower shall be so applled as to secure the east loss and greatest capacity attainable.

To this end the invention consists in providing such connection between thepunch actuating or engaging arm and the operating lever that the eccentric or cam of the operatmg arm is so guided during the period of greatest stress or effort as to produce a rolling contact between said cam surface and the punch actuating arm in order to avoid loss of power due to friction and slippage between such surfaces. Incidentally the guiding means employed for this purpose serve also to act as a means for lifting the punch engaging arm in order to strip the punch from the metal with the greatest economy of power.

In the accompanying drawings I have illus trated a preferred form of embodying my said invention of which Figure 1 is a side elevationshowing the parts in position to begin the punching operation. Fi 2 is a frontelevation thereof. Fig. 3 is a side elevation of the device incentral section.

In the practice of my invention as illustrated in the drawings I employ a relatively heavy member or arm 1 which may be termed the stationary arm or member provided with a common U-shaped jaw the lower portion of which carries the female member or die 7. The operating arm or lever 2 is pivotally connected with said stationary arm by means of a pair of swinging links 4 This operating lever has its lower face adjacent to its pivotal axis 8 curved to form a cam surface eccentric to its pivotal axis, said cam surface. being desi nod to act against the opposed upper face 0 0 the swinging arm 3 which is pivoted to the stationary member 1 by means of the pivot pin 9. The stationary j aw is provided on either side with the lugs or trunnions d to form fulcra for the swinging levers 4. The punch 6 is. slidingly mounte in the vertical bore of the upper jaw of stationary arm 1 and at its upper end is formed with an annular groove so as to leave an enlarged head or shoulder b which is engaged by the forked lower end of the punch actuating arm 3.

Obviously if no guiding means were employed the depression of the o crating lever 2 would serve to force down t e front end of the punch engaging arm 3 by means of the action of the cam surface a to force the punch through the metal but in such case there would be considerable sli between the cam surface a and theoppose surface 0 and the raising of the lever would not act to strip the punch from the work. I therefore provide a pair of links 5 whose upper ends are connected with the operating arm 2 by means of the pivot pin 11 and whose lower ends are pivotally connected to the forward end of the arm 3 by means of the pivot 10.

The centers 10 and 11 are so disposed with reference. to the center 8 that as the lever 2 is depressed on its axis 8 the links 5 act to swing said axis 8 about the center (1 so as to produce rotation in the same direction about the center d as the rotation of the arm 2 about the center 8. The proportions are so designed that the advancing of the axis 8 about the center d by the depression of the arm 2 serves to give a rolling contact of the cam surface a upon'the opposed surface 0 so as to eliminate any appreciable slip between these two members during the period of greatest stress or strain. The ractical elimination of slip at this point wi obviously prevent a considerable loss of the power applied.

While I have shown as a matter of convenience the pivotal axis or fulcrum 10 of the guide links 5 as being carried by the pivoted arm 3, it will of course be understood that such an arrangement is not essential, the, important point in this respect being that the fulcrum of the guide links should be outside of the power arm 2 and the supporting links 4 which carry the fulcrum or axis of the power arm. Indeed so far as the punching operation is concerned the arm 3 might be dispensed with but of course in that case other means would be required for stripping the working member from the work after each operation. At the same time the links 5 are so arranged that after the punching o eration has been completed the raising of tl fe lever 2 will act during the last part of the u ward stroke to exert an upward pull upon t e arm 3 by means of the'links 5, the action in this case being in effect to make of the links 4 and the lever 2 a toggle joint, the straightening of which tends to pull the arm 3 and the punch 6 upward. In this way the guiding means by which the proper rolling action is secured, serve also to act as stripping links to exert a powerful pull to strip the punch from the work.

To prevent the swinging upward of the operating lever 2 beyond the point necessary to give proper clearance above the work after the stripping of the punch, I provide on the aw 1 stop shoulders f in position to be engaged by the projecting lugs e formed on the swinging links 4 so that as the links swing in a contra-clockwise direction these shoulders and lugs serve to limit such movement to the point required to give proper clearance for removing the work.

While I have described this invention as applied to a metal punch it is obvious that the same principles are applicable to the construction of a metal shear or a riveting machine or other metal working implement.

What I claim is 1. In a metal working implement the combination of the stationary arm, the swinging arm pivotally connected thereto, an operating lever having link connection with said stationary arm, said operating lever being provided with an eccentric cam surface disposed to engage the swinging arm to actuate the same, and guiding links for producing a rolling contact between said cam surface and.

the adjacent face of the swinging arm.

2. In a'metal working implement the combination of a stationary member in which a movable working member is supported, a power lever provided with a cam surface for actuating said working member, the fulcrum or axis of said power arm being movable, and a guide link pivotally connected with said power arm to control the movement of its axis when the power arm is actuated, substantially as described.

3. In a metal working implement the combination of the stationary member, a power lever pivoted to swing about a movable axis,

guidingmeans having pivotal engagement with said lever to move the axis thereof in the same rotative direction as that in which the lever moves, substantially as described.

4. The combination of the stationary member, the pivoted links connected therewith, a power arm, a fulcrum at the free ends of said pivoted links, a guide link fulcrumed outside of the power arm and having pivotal connection with said power arm whereby when the power arm is actuated the supporting links, the power arm and the guide link are rotated about their respective axes in the same direction of rotation.

5. The combination of the statiomrry member, the punch engaging arm pivoted thereto, the power arm, supporting links therefor which are pivotally connected to the stationary member, stripping links forming a pivotal connection between the punch engaging arm and the power arm to cause the supporting links to swing on their axis as the power arm is depressed, and stops for limiting the reverse movement of the supporting links when the power arm is raised, substan tially as described.

6. In a device of the class described the combination of the stationary member, the punch engaging arm, the power arm having a cam surface adapted to engage the punch engaging arm, pivoted supporting links in which the power arm is fulcrumed, guiding links forming a pivotal connection between the punch engaging arm and the power arm, and means for limiting the upward movement of the power lever, substantially as described.

7 The combination of the stationary member, the punch engaging arm pivotally mounted thereon to actuate the punch into and out of the work, a power arm i'ulcrumed in swinging links connected to the stationary member, said swinging links being provided with a projecting stop adapted to engage an opposing stop on the stationary member to limit the stripping movement of the power arm, guiding and stripping links pivoted at one end to the punch engaging arm and at their other ends to the power arm, substantially as described.

In witness whereof, I have subscribed the above specification.

ARTHUR I1. GODDARD.

In the presence of GEORGE M. BENNETT, ALFRED R. GODDARD.

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