US699350A - Power-press. - Google Patents

Description

Patented may 6, |902.

G. B. TENNA'NT.

POWER PRESS.

(Application led Aug. 4, 1909.)

.y (la Model.)

INVENTOR Patented May 6, |902. G. B.' TENNANT. Y

POWER PRESS. (implication n leamfg. 4, woo.)

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Unire STATES Arnim @prima GEORGE BuTENNANT, OF JOIINSTOVN, PENNSYLVANIA.

POWER-PRESS.

SPECIFICATIN forming part of Letters Patent No. 699,350, dated May 6, 1902.

Application filed August 4,1900. Serial No. 25,890. (No model.)

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Beit known that I, GEORGE B. TENNANT, of Johnstown, Cambria county, Pennsylvania, have invented a new and useful Improvement in Power-Presses, of which the following is a full, clear, and exact description, reference being hadto the accompanying drawings, forming part of this specification, in which- Fignre 1 is a side elevation, partly in section, ot'l a punching-press constructed in accordance with myinvention. Fig. 2 is a front elevation of the same. Fig. 3 is a vertical section on the line III III looking toward the rear. Fig. 4 is a side elevation, partly in section, ot a compression-riveter embodying my `invention. Fig. 5 is a front elevation of the same; and Figs. 6 and 7 are sectional views on the lines VI VI and VII VII, respectively, of Fig. 4.

My invention relates to that class of presses and similar machines wherein power is applied through a toggle-joint device; and its object is to improve the economy and cost of running of such machines and to render them adjustable for diierent classes of work by adjusting the Xed pivotal point of the toggle device. In machines of this class-such as riveters, punches, shears, presses, forging and upsetting machines, coining and embossing presses, bending -machines, &C.-there must be a certain allowance of stroke over and above the maximum rated capacity of Work for clearance, stripping, dac. No useful work is done in this portion of the stroke, as friction and weight of the parts only are to be overcome, and consequently little power is required. This portion of the stroke also varies with dierent work.

My invention is designed to provide simple and eiective mechanism which may be applied to any machines of this character employing the toggle-link actuating device and which will both adjust the tool quickly and easily for different styles ot' work and also give the light portion of the stroke economically before the full power of the machine is applied.

To that end the invention consists, broadly, in mechanism for adjusting the fixed pivoted point of a toggle-joint wherein a longer and a shorter lever are pivoted together, and the power is applied directly to the joint between these levers, thus adjusting the position of the tool before the working part of its stroke, and, further, in providing automatic means for thus adjusting the tool and moving it through the non Working portion of the stroke quickly and economically.

In the drawings, referring'to Figs. 1, 2, and 3, in which I show my invention as applied to a punching-press, 2 represents a casting forming the main frame of the machine, this casting being formed hollow to receive the working parts. This frame is provided with the usual lower die-block 3, containing the holder and die 1l, there being aslot 5 below the die, through which the punchings are removed. The punch 6 is secured tothe lower end of a punch-stock, secured to a rectangular vertical plunger 7, moving in a suitable guide in the frame 2. This plunger is actuated by a steel operating-lever 8, having a fixed pivot 9 or fulcrum-pin carried in bearings in the main frame. To the rear end of lever 8 is connected the main pressure-links 10 of the toggle-joint, the upper ends of these links be-l ing pivoted to the pin 11 of the toggle-joint.

The lower pin 12, connecting the links 10 and the lever 8, is providedl with loose depending links 13, through whichextends a pin 14, the ends of which are secured in the main frame, as shown in Fig. 3. These links serve to limit the motion of the operatinglever.

The main toggle-links 15 are connected at their upper ends to the pivot-pin 11 and at their lower ends to a rocker-bar 16, pivoted to the frame by a pin 17.

The toggle-joint is actuated by piston-rod 18, pivoted in the large trunk portion 19 of piston 20. This piston is placed Within the main motive cylinder 21, which in the form shown is placed above the smaller supplemental cylinder 22. This small cylinder 22 is employed to adjust the position of the main pin 11 of the toggle-joint through the links 23, pivoted to the rock-arm at 24 and having at their upper ends projections 25, which enter square inclined grooves in a horizontallysliding head 26, connected to and actuated by the piston 27 of the cylinder 22.V The head 2G slides on suitable guides on the main frame by the movement of the small piston 27,vhich I have shown as moved to the center of its cylinder, bringing the plunger to the desired point on the Work. This movement is caused by the action of the inclined faces of head 26, acting through the vertical links 23, the rocker-bar, the side links 15, the pressurelinks 10, and the main operating-lever. The

two arms of this main lever in the form shownv are of lengths in ratio of one to four, and a vertical movement of one inch of its plunger end would give a movement of about four inches of the pin l2. To obtain this movement would give a longer stroke of the small piston than is desirable, and hence I employ the rocker-arm 16, to which the links 23 are pivoted midway of its length. A vertical movement vof four inches at its outer pivot requires a movement of two inches at its pivotal connection with the links 23. The inclined grooves in head 26 are at an angleof one to six, and the stroke of the small cylin*` der is twelve inches, thus giving the required movement. After this initial movement is given by admitting pressure at the front end of a small cylinder and moving the head 26 toward the rear of the machine until the punch is in contact with the piece pressure is admitted to the rear end of the main cylinder, putting itspiston-rod in tension and actuating the toggle so as to raise the rear end of operating-lever S and force down the plunger to punch the hole. After the hole is punched pressure is admitted at the front end of the cylinder 2l, thus reversing the action of the toggle and forcing the piston back to theposition shown. Pressure is then admitted to the rear end of the small cylinder 22, thus forcing down the rocker-bar and the rear end of the operating-levers and lifting the punch to clear it. A stripper is preferably provided to clear the punch from the metal, and the small cylinder thus does the work of stripping.

The valve mechanism for controlling the cylinders may be of any desired form, and I have shown two rolling valves 29 in the heads of the cylinders, these being operated bythe single lever 30. The loose links 13 serve to limit the stroke, and it is desirable to make the light part of the stroke as great as possible'. Hence in the case shown for material the form shown in these figures the togglejoint is intentionally arranged so that its greatest power is not applied. The toggle thus acts as a safeguard, so that if a piece of metal is inserted which is far beyond the capacity of the machine and the pressure applied there will be no injury to the machine, as the power is definitely limited.

It will be noted that the main power is not used except when useful work is done. This gives longer life, owing to less wear of moving parts. The slope of the grooves in the sliding block is equal to or a little less than the angle of friction, so that it gives a positive holding device at all points, and the pressure is transmitted through it direct vto the main frame by means of the tension-links.

In the case of a punch having a larger frame with greater depth of throat the rocker-bar would not be necessary, as sufficient movement could be obtained from the sliding head.

It will be understood that my invention is applicable to many different machines, and in Figs. 4 to 7, inclusive, I show itapplied to a compression-riveter.. In these figures, 3l represents the main frame formed of the steel casting and havingits upper jaw of box form to receive the rocker-bar This bar is pivoted to the pin 33, carried in bearings in the main frame, and is actuated by link 34, connected to its rear arm by pin 35. The upper end of'this link is provided with lateral pro-v` jections 36, engaging the inclined square groove 37 of horizontally-slidinghead 38. This head slides on a suitable way on the upper jaw and is held down and guided by the guide-piece 39, which is bolted to the frame of the machine and extends over it, as shown in Fig. G. The head 3S is connected by a cross-head 40 with the piston-rod 41 of the small motive cylinder 42, and the cross-head is provided with an upward projection 43, which is arranged to strike the endof an adjustable stop or gage 44, which is adjustably clamped to the top of the guide-piece 39 by a clamp 45, secured by bolts 46. These bolts are actuated by wrench 47, and by means of the clamp the stop may be held in any adjusted position, thuslimiting the forward movement of the head 3S.

The main side links 43 of the toggle-joint are pivotally connected to the front arm of the lever 32 by the trunnions or hubs 49 and at their upper arms take about the main pin 50 of the toggle-joint. The piston-rod 5l, connected tothe trunk portion 52 of piston 53, is connected at its front end to the main pin 50, and to this pin is also connected the pressure-link 54 of the toggle-joint. This pressure-link is pivotally connected to the upper enlarged portion of the plunger 55, which eX- tends down through a curved slot 56 in the lever 32 and is provided at its lower end with the removable rivet die orsnap 57. The lower rivet die or snap 58 is secured to the lower jaw in the usual manner.

In the machine shown the movement of IOO the plunger 55 when operated by the small cylinder 42 through the sliding head 38, link 34, and lever 32 is four inches. The movement of the plunger 55 when operated by the toggle-joint actuated by main cylinder is two inches. In using the machine, the main toggle being in the position shown in Fig. 4, it is brought to the work and the plunger lowered by admitting pressure to the rear end of small cylinder. A small block of metal two inches thick is placed on the work and the plunger lowered by small cylinder until the dies grip the work and the two-inch piece. In practice the thickness of this block will be less than two inches, the plunger-stroke of main toggle by the amount of deiiection of the steel frame of the machine as actually measured. The adjustable gage 44 will then be moved up to contact with the cross-head and clamped in this position. The plunger is. then raised by admitting pressure to the front end of the small cylinder and exhausting to its rear, and the block will be removed, and the machine thus set for driving all rivets in this thickness of metal.

In driving the rivets the pressure is admitted to the small cylinder to move the sliding block until stopped by the gage. It will be apparent that the vertical motion of the plunger thus produced will not bring the toggle-joint into play, but will change the position of the main toggle-pin, this motion being allowed by the trunk on the main cylinder and the piston-rod turning on its pin in this trunk as the position of the main toggle-pin is adjusted. Pressure is then admitted to the rear end of the main cylinder, thus actuating the toggle-joint and forcing down the plunger the stroke of the toggle and closing the rivet. Pressure then being admitted to the front end of the cylinder the togglejoint is moved back to its normal inoperative position and pressure uid is then admitted to the smaller cylinder, thus giving a further lift to the plunger.

-Tol equalize the angularity of the pistonrod 5l in the different positions of the main toggle-pin, the main cylinder is preferably placed so that its center line extends through the center of the main toggle-pin when the joint is straightened, the adjusting-lever being then in its central position, asshown in Fig. 4.

Vhen the adjustable stop is fixed in its adjusted position, the machine will operate properly on all work of the same thickness, and when used on work of dierent thickness the stop will be correspondingly changed.

The advantages of my invention upon machines of this type will be appreciated by those skilled in this art, since the screw-piece which has heretofore been used toadj ust the upper rivet-die and which was a source of great trouble on account of distorting of the threads and bending and breaking of the screw under the heavy pressure is done away with. Moreover, the accidental changing of the position of the screw is obviated.

In this machine the cylinders may be operated by the large rolling slide-valve 59, placed in the common rear head of the cylinder and actuated by the single lever 60, or the cylinders may be controlled by any suitable valve mechanism.

The advantages of my invention result mainly from the adjusting of the iixed point of the toggle-joint, which feature I believe to be new and intend to cover broadly in its application to any machine of the general type described. As above shown, this feature lengthens the life of the machine and makes it more economical of power. The use of the inclined abutment-blocks for adjusting is also of great advantage, as it enables different adjustments to be quickly and easily made to suit the machine to different classes of work and renders the machine compact and simple.

The invention may be applied to widelydiierent machines wherein power is exerted through a toggle-joint or direct cylinder, and the arrangement of the toggle-joint and the means for adjusting its vfixed point, as well as the motive connections, may be varied widely without departing from my invention. In double drawing-presses the system may be used with two or more main toggles.

By the term power-press in the claims I intend to cover, broadly, any machine wherein power is applied to the tool through a tog'- gle-joint connection.

I claim l. A power-press having a toggle-joint, means for actuating the toggle-joint, and power-actuated mechanism arranged to automatically adjust the ixed point of the toggle and thereby change the position of the tool; substantially as described.

2. A power-press having a toggle-joint arranged to actuate a tool, means for actuating the toggle-joint, and an inclined block having connections arranged to adj ust the fixed point ofthe toggle; substantially as described.

3. A power-press having a toggle-joint arranged toactuate a tool, a cylinder arranged to actuate the toggle-joint, and another cylinder having connections arranged to automatically adjust the fixed point of the toggle; the latter cylinder being of insufficient power to actuate the tool in its working stroke, and arranged to merely adjust the position of the tool substantially as described.

4. A power-press having a toggle-joint connected to and arranged to actuate a plunger, a lever connected to the plunger, and means for swinging the lever to adjust the ixed point of the toggle; substantially as described.

5. A power-press having a toggle-joint connected to and arranged to actuate a tool, a lever connected to the toggle, a link connected to the lever and having an inclined face, and a sliding block having an inclined face arranged to act upon the link to adjust the po- IOO IIO

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sition of the fixed point of the toggle; substantially as described.

6. A power-press having a toggle-joint connected to and arranged to actuate a tool, a lever connected to the main links of the toggle and' arranged to change the fixed point of the toggle, and mechanism for swinging the lever; substantially as described.

7 A power-press having a toggle-joint arranged to actuate a tool, a cylinder arranged to actuate the toggle, and automatically-acting mechanism arranged to adj ust the position of the fixed point of the toggle and drawing the tool to the desired point before the toggle-link is actuated to move the tool; substantially as described.

8. A power-press having a toggle-joint arranged to actuate a tool, a cylinder arranged to actuate the toggle-joint, and a smaller cylinder having connections arranged to adjust the fixed point of the toggle; the latter cylinder being of insufficient power to move the tool through its working stroke substantially as described.

9. A power-press having a toggle-joint arranged to actuate a tool, mechanism for adj usting the fixed point of the toggle and an adjustable stop arranged to regulate the amount of said adjustment; substantially as described.

10. A power-press having a toggle-joint arranged to actuate a tool through a pressurelink, a lever connected to the main side links of the toggle, a link connected to the lever and having an inclined face, a sliding block arranged to act upon the link, an adjustable stop for the block, and a power-cylinder connected to the block; substantially as described.

ll. A power-press having a toggle provided with two levers of different lengths connected together at their adjacent ends, the shorter l lever being arranged to actuate the tool, the longer lever having an adjustable fulcrum at its opposite end, said opposite ends of the levers both being on the same side of the joint between the levers, means for applying power to said joint, and mechanism for adjusting the fulcrum of the longer lever; substantially as described.

l2. A power-pressl having a toggle device formed with a longer and a shorter lever with their ends connected together, the opposite ends of the levers both being on the same side of the 'joint between the levers, a lever connected to the other end of the shorter lever and arranged to actuate the tool, means for applying power to the joint between the two toggle-levers, and an adjustable fulcrum for the longer lever; substantially as described.

13. A power-press having a toggle-joint formed of a longer and a shorter lever pivotally connected at their ends, a power-cylinder connected to the joint between the two toggle-levers, the opposite ends of the levers both being on the same side of the joint between the levers, a third lever pivotally connected to the opposite end of the shorter lever and arranged to actuate the tool, a fixed fulcrum for the opposite end of the longer lever, and mechanism for adjusting said fulcrum; substantially as described.

14. A power-press having a toggle-joint formed of a longer and a shorter lever pivotally connected at their ends, a power-cylinder connected to the joint between the two toggle levers, a third lever pivotally connected to the other end of the shorter lever and arranged to actuate the tool, a fixed fulcrum for the other end of the longer lever, and mechanism for automatically adjusting the fulcrum to bring the tool to the desired point; substantially as described.

In testimony whereof I have hereunto set my hand.

GEO. B. TENNANT.

Witnesses:

L. M. REDMAN, G. I. I-IoLDsHIP.

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