US2082334A - Compression riveting or punching device - Google Patents

Description

June 1, 1937.

G. T. HARCOURT COMPRESSION RIVETING OR PUNCHING DEVICE Filed March 30, 1935 4-SheetsSheej: 1

3 A/EUTEAL MIMI! m INVENTOR v zo/eos 7.-

ATTORNEY June 1, 1937. G. T. HARCOURT 2,082

I COMPRESSION RIVETING OR PUNCHING DEVICE Filed March 30, 1935 4 Sheets-Sheet 2 FORM/4E0 INVENTOR Giza/e 5 7641/?(04/27:

ATTO R N EY June 1, 1937. i HARCOURT "2,082,334

COMPRESSION RIVETING OR PUNCHING DEVICE 7 Filed March 30, 1935 4 Sheets-Sheet 3 5 7 1 -17- I i Ti Ill ATTORNEY r June 1, 1937. e. T. 'HARCOURT 2,082,334

COMPRESSION RIVETING ORfUNUI-IING DEVICE Filed March so, 1935 4 Sheets-Sheet 4 A/Eufe/u.

IYNVENTOR j ATTORNEY.

Patented June 1, 1937';

COMPRESSION- RIVETING 0R PUNCHIN G DEVICE George T. Harcourt, Detroit, Mich., assignor to Chicago Pneumatic Tool Company, New York, N. Y., a corporation of New Jersey Application March 30,

15 Claims.

This invention relates to machines for riveting, punching, or the like, by means of which the rivets or other material operated on are subjected to squeezing or pressing action, as distinguished from a series of blows. For convenience, certain of the objects of the invention will be described with reference to a riveting device, although the improvements to which they relate may also be embodied in a machine for punching holes in metal plates.

One of the objects of the invention is to provide a hold-down device which clamps the plates that are to be riveted to each other and holds the rivets firmly in' the proper position before any riveting action takes place.

Another object is to enable the hold-down device to clamp one or more metal sheetsor plates in proper working position, irrespective of the thickness of the sheets.

A further object is to operate the hold-down device by a piston which also operates the power plunger without causing any appreciable reduction in the power applied to the plunger.

A still further object of the invention is to provide a high ratio between the pressure of the plunger against the rivet and the force of the piston which actuates the plunger.

Another object is to move the plunger first rapidly toward the rivet and then more slowly but 7 with increasing force.

A feature of the invention resides -in power transmitting mechanism between the piston and plunger which operates with av minimum of friction.

Still another object is the provision of a. punch with positive means for withdrawing the piercing tool from the work. I

Another feature, of the invention resides in an arrangement for maintaining the operative relation between the hold-down device and the work until the piercing tool has'been withdrawn. This feature is particularly useful in operating upon material tending to cause the piercing tool and hold-down device to become stuck.

An additional feature ofthe invention resides in a. novel valve mechanism which is simple in construction and easy to manipulate. I

Other objects and features .of the invention will appear more clearly from the following description taken in connection with the accompanying drawings and appended claims.

'In the drawings, which illustrate two alternative embodiments of the invention, Fig. 1 is aview of. a riveting machine shown partly in elevation and partly in section along a plane indicated by the arrows l-l in Fig. 2, the valve lever being.

shown in the inoperative position and the piston at the rear end of the cylinder;

Fig. 2 is an end elevational view ofthe machine:

shown in F18. 1;'

1935, Serial No. 13,842 (01'. 74-110) Figs. 3 and 4 are fragmentary sectional views looking downwardly as indicated by arrows 3-3 and 4-4 respectively, in Fig. 2;

- Fig. 5 is a view similar to Fig. 1 showing the parts in the position that they occupy after the piston has moved forwardly far enough to engage the hold-down device with the work;

Fig. 6 is another view similar to Fig. 1 but showingthe piston at the beginning of its rearward stroke;

Fig. 7 is a fragmentary sectional view looking downwardly along the broken line 'I-'l of Fig. -1;

Fig. 8 is a longitudinal sectional view of the yoke frame looking in the same direction as Fig. 1;

Fig. 9 is a cross section extending through the yoke frame as'indicated by the arrows 9-3 in' chine showing the piston at the beginning of its working stroke; and

Fig. 13 is another view of the machine shown in Fig. 12, with the piston at the beginning of its return stroke.

The embodiment illustrated in Figs. 1 to 11 inclusive comprises a yoke 15 whose upper portion I 6 is dovetailed to fit a'yoke frame i'l. As shown best in Figs. 8 and 9, the yoke comprises a body portion l8 of arcuate shape open at the bottom and having two depending walls l9, the lower ends of which are provided with tongues 20, which are slidably mounted in grooves 2! on the yoke. Bolts 22 hold the yoke and yoke frame rigidly in assembled relation. The rear end of the yoke frame has a'cylindric'al projection 24,

whose lower end is-provided with'a slot 25 of' the same thicknessas the space between the walls is, and a narrower'slot 26.

A cylinder 28 having a flange 2811 at its forward end is sleeved over theprojection 2d.' Screws 29 secure the cylinder flange to a flange Ila on the tion' with the projection 24' on the yoke frame and] provides a front head for thepiston chamber.

Any suitablemeans'may be provided for controlling the admission of air to'the cylinder for reciprocating the piston :As shown in'the drawings the valve mechanism is contained within a housing 35 which is cast integrally-with the: yokeframe l'l, Thehousing 35: has a threaded open-- ing 36 at its upperend for. connection with a supply pipe 31 forthe' admission of live air-or 60 other motive fluid. Fourvalve members, 39,. 40,

4|, and, are arrangedin the housing 35, each member having a cylindrical stem provided with a head at one end, and all valve members extending in a horizontal direction. Valve member 39 5 is mounted within a stem receiving bore 39a, a front counterbore 39b and a rear counterbore 380. Similar bores and counterbores 40a, 40b, 40c, and Ma, Mb, 0, and 42a, 42b, 42c are provided for the othervalve members 40, 4|, and 42 respec- 10 tively. Each rear counterbore is closed by a plug 45 .and a spring 46 extends between the plug and the head of the valve to urge the latter towards its seat, thereby to cut of! conmiunication between the front and the rear counterbores.

5 -Movement of the valve members against spring pressure is accomplished by means of a lever 48 pivotally mounted on a horizontal pin 41 supported by ears 48 at the front of the housing 35. Throttle handle 50 is secured to one end of the 20 lever to provide means for manipulating the latter. The valve lever 46 has three positions of adjustment; neutral, as shown in Fig. 1, which permits seating of all valve members; forward, as shown in Fig. 5, in which only the upper valve 5 members 39 and 40 are forced off their seats; and reverse, as illustrated in Fig. 6, in which only the lower valve members 4| and 42 are unseated.

The rear end of the cylinder 28 is connected 30 to the valve housing 34 by means of a pipe 52 which extends through cylinder flange 28a and communicates with passage 52a, which is connected at all times to counterbores 39b, 42c. The cylindrical projection 24 of the casting has a passageway leading from the front end of the cylinder to a'set of passages 54a in the valve housing which are connected to counterbores 4") and 400. Live air passages 55 connect the supply pipe 3'! with the rear counterbores 39c and He, 40 while exhaustports 56 vent th e fr0nt counterbores 40b and 42b 'to atmosphere, or other-suit- I the throttle handle is moved to the forward position, which is shown in Fig. 5, the upper set of valve members 39 and 40 are forced of! their seats and thereby establish communication between counterbores 39a and 39b and also between 40a and 40?). Live air is admitted to the 7 rear end of the cylinder through counterbores 390,,39b and passages 52a and 52. At the same time valve member 40 opens the front end of 60 the cylinder to exhaust through passages 54, 54a,

and 56. As a result, the piston is driven forwardly. When the throttle handle is rocked to the opposite, orFig. 6 position, valve members 4| and 42 are forced of! their seats thereby admitting live air 'to the front end of the cylinder through passages 54a and 54, and simultaneously exhausting the rear end through passages 52 and 52a, as a result of which the piston is returned to its Fig. 1 position.

The power transmitting mechanism actuated by the piston will now be described. The front end of the piston rod 3i has a recess 51 which receives a portion of a yoke member 5.. A threaded rod 59 holds the yoke member securely aosaass to the piston rod. The yoke member supports a central roller 60a and two side rollers 60b. The side rollers are guided at the top by track 62 removably attached to the casting ll. Rollers 60b also rest upon two levers 62b pivoted at their rear end to a pin 84 extending across slot 26 in the projection 24 on the casting. Each of the side levers 2b,.at its front end, is provided with a nose 65 whose upper and lower edges are rounded for pivotal engagement with a hook shaped arm 66. There are two .of these arms arranged in spaced relation and.connected at the bottom with a sleeve 61 reciprocably mounted in vertical bore 88 in the yoke l5.

The sleeve 88 is aligned with a. dolly or-work supporting means 10 on the yoke l5, and the purpose of the sleeve is to act as a guide and hold-down device during the riveting operation.

A power plunger II is slidably'mounted within the sleeve and projects beyond the upper end of the latter. The upper end of the plunger has a slotted head 12 situated between the two it will be seen that the power plunger ll and hold-down'sleeve 61 are carried by the central lever 63a and side levers 63!) respectively at the front ends of the latter.

The levers are urged upwardly by a wire spring 15 of generally U-shape in plan view, as seen'in ,Fig. 7. The mid portion of the spring is in the form of a short horizontal arm 16 which engages the lower edge of the intermediate lever a and forces it upwardly. Integrally connected with the horizontal arms are three sets of parallel arms, each set being in a different plane and adjacent sets being separated by coiled portions .10 which surround pins 19 supported by the yoke frame I]. The rear ends of the parallel arms terminate in inwardly projecting end portions bearing upwardly against side levers "b,

The upper edgeof the central lever 63a is uniformly straight, and so arranged that the cen-' tral roller ill passes over this edge for substantially the entire length of the lever, and forces .lever "a downward with a wedging action of increasing pressure. The side levers, however, are of such shape that they do not come into direct contact with the rollers excepting for a short distance along the upper edges "c.

The operation of theriveting machine shown in Figs. 1 to 11 inclusive is as follows: Assume that the parts are. in the Fig. 1- position with the piston 20 at the rear end oi. the cylinder and the levers 63a and 63b elevated by the spring Ii. The operator turns the throttle handlelll to the forward or Fig. 5 position thereby admitting air to the rear end of .the cylinder for driving the piston forwardly as described hereinbefore. Movement of the piston through a slight distance causes the rollers to pass over the upper edges of the three levers tending to wedge them downwardly. Am 16 on spring ll holds the front end of the central lever in raised position while the rear end is depressed. Pin I4, whichacts as a fulcrum for the central lever, continues to drop with the side levers until the latter are positively stopped by the engagement of the hold-down sleeve 61 with the material M upon which the machine operates. The operation of the sleeve 61 is also effective to squareup the rivet in proper relation to the plunger II. Fig. shows the parts of the riveting machine in the position occupied just after the holddown sleeve 61 has been operated and movement of the fulcrum pin 14 has been arrested. Continued forward movement of the piston causes the central roller to act as a wedge upon the lever 63a which operates the power plunger. The plunger starts to move rapidly due to the high ratio between the total length of the lever and the distance separating roller 60a from the 15 fulcrum 14. As the roller 60a moves away from the pivot point I l and toward the plunger, this ratio decreases and further movement of the plunger is less rapid but is capable of exerting a greater force. By the time the piston reaches the extreme forward position; which is illustrated in Fig. 6, the downward pressure transmitted to the plunger is practically equal to the .vertical component of the wedging force applied to the lever 63a by the roller. This vertical component is many times greater than the horizontal component (which corresponds to the forward pressure of the piston) due to the constantly decreasing angle of inclination of the upper edge of lever 630.. Thus the plunger II is forced against the rivet with a pressure many times greater than the force of the piston 30.

After the rivet has been operated on, the operator throws the throttle lever 50 to reverse position which is illustrated in Fig. 6. As the v5 piston moves rearwardly, plunger II is lifted by spring 15. The hold-down sleeve does not accompany the plunger in this upward movement for the reason that upward spring pressure against the central lever tends to rock the lever about the surface of roller 60a and thereby holds the pivot pin 14 indepressed position. When the rollers approach the pivot pin 14, the holddown sleeve is raised under the influence of the free ends 80 on spring 15. Thus the hold-down sleeve is held against the material M until after the power plunger has been withdrawn by the spring.

- Figs. 12 and 13 illustrate a punching machine embodying certain features of the invention. Several of the parts of the riveting machine in Fig. 1 may be employed in the punching device. These include the yoke l5, yoke frame 11, cylinder 28, valve mechanism, piston rod 3| rollers 60a and 60b, and track- 62 all arranged substantially the same as in the riveting machine.

In the punching machine, the levers are arranged in a modified relationship; designed to provide positive means for withdrawing the punch from the sheet or other'materi'al in which the punching tool may be stuck. Referring to Figs. 12 and 13, the hold-down sleeve 81 has a pivotal connection at its upper end with two side levers 88b which are pivoted at their rear ends to the fixed pin 89. A punching tool 90, received within the sleeve, is carried at its upper end by a socket head 9| which pivotally receives the front 'end of the central lever 88a. Levers 88a and 8812 are pivotally connected to each other by a pin 92, spaced a substantial distance from the ends of both side and central levers. One or both of the side levers has a heel 93 adjacent the pin 89 which has an arcuate'surface adapted to be engaged by cooperating roller 60b when the piston is at its rearmost position. The top edge of the central lever has two angularly' disposed surfaces 88c and 88d both engageable with the roller 60a. A spring urges both the central and side levers upwardly.

In the operation of the punching device, forward movement of the piston causes the side rollers to bear upon the levers 88b to lower the hold-down sleeve 81 into operative relation with the dolly 96 and the sheets S or other material to be punched. When the side levers are depressed, they lower the pin 92, thereby withdrawing the central lever from the path of the roller 60a and permitting the latter to move forward. After the rollers reach-the approximate position of the pin 92, roller 60a engages the edge 88d of thecentral lever and further movement of the roller along this'edge forces the lever and punching tool downwardly with increasing pressure.

After the hole has been punched, the operator turns the throttle lever to reverse position and the piston starts rearwardly, the parts being then in the position shown in Fig. 13. The sleeve 81 is held down due to the grip of the sheets S on the sleeve and on the punch 90. When the rollers reach the edge 880 on the central lever, the pressure of the roller against the lever tends to lower the pivot pin92. The pivot pin cannot move down inasmuch as the sleeve 81 is stillfirmly against the sheets and, therefore, the opposite end of the central lever 88a must pull up and the sheets are stripped from the punch. As soon as punch is clear from the sheets the spring forces all the levers up against the rollers and when the piston completes its return stroke the levers again take the position shown in Fig. 12.

The heels 93 on the side levers cooperate with the rollers to restore these levers to the normal or Fig. 12 position. The combination'of the heel and the spring assures full open position and accurate control on the down stroke of the punch 90. In other words, the spring acts to prevent the punch and sleeve from suddenly dropping when the roller leaves the heel on the forward stroke.

Both forms of the invention utilize a central or plunger-operating lever which has .a movable fulcrum that comes to rest in response to the seating of the hold-down device. As a result of this construction, operation of the power plunger or punching toolis delayed until the hold-down device has been operated, whereby no power is spent on the hold-down mechanism during the riveting or punching action.

The novel arrangement of levers acts as a differential to permit the piston to move for a full stroke irrespective of the length of stroke of the hold-down sleeve, which varies in accordance with the thicknesses of the materials to be clamped. During the greatest part of the stroke of the piston, the rollers do not engage the outside or hold-down levers directly but .transmit their pressure through the central or power plunger lever. Within wide limits, the hold-down levers may come to rest at any position and further movement of the rollers is not interfered with but is effective to rock the central lever about a fixed fulcrum.

The invention is not restricted in its application to riveting and punching machines. The principles described herein may be employed for pulling nails or wedges and are particularly advantageous where power must be applied to obtain a grip on the piece to be pulled, such as a nail with the head buried. The invention may all also be used in assembling operations where bushings or pins are to be pressed into place. The hold-down device may be used to square up the bushing or pin so that the power plunger will press it into the hole properly and not cut the hole or deform the pin or bushing.

A further advantage of the illustrative embodiments of the invention is that they may be used in places where the rivet or other device operated.

on is close to a wall or at any place where the work requires a compression action similar to that of pliers.

What is claimed is:

1. A mechanical movement comprising a power operated piston, a frame having a track extending parallel to the piston, one or more rollers carried by the piston and engaging the track, a power plunger extending at right angles to the axis of the piston, a lever pivotally supported in the frame and operatively connected at one end with the power plunger, and a roller carried by the piston adapted to roll over the lever and cooperate with the track to form a wedge for forcing the lever and power plunger away from the track.

2. A mechanical movement according to claim 1 in which the last-mentioned roller engages a straight edge on the lever at an acute angle to the track, and said roller moves along this edge away from the pivotal support for the lever, whereby the moment of the force tending to turn the lever increases as the piston moves forwardly.

3. A mechanical movement according to claim 1 in which the lever is adapted to move the power plunger in both directions and the lever is urged toward the track by a spring.

4. A power operated machine comprising a yoke, said yoke being perforated to receive a power plunger, a yoke frame connected to the yoke and providing a ,housing in which the plunger is received, a track supported by the yoke frame at the upper wall of the housing, a lever pivotally connected to the plunger at its forward end, a pin for pivotally supporting said lever, the upper surface of said lever converging toward the track in a forward direction, a power operated piston carrying one or more rollers at its forward end adapted to ride over said track and, cooperate with the latter to form a wedge for forcing the lever downwardly, a carrier for said supporting pin, and yieldable means for urging said carrier and pin upwardly against the pressure of the piston.

5. A power operated machine comprising a frame, a power plunger mounted for reciprocation in said frame, a hold-down device having one or more parts reciprocating in a direction parallel to the power plunger, a pair of elongated levers arranged side by'side and connected at their forward ends to the plunger and hold-down device respectively, the rear end of the hold-down lever being pivoted on a pin fixed to the frame and the rear end of the plunger lever being pivoted on a pin carried by the hold-down lever.

6. A power operated machine comprising a frame, a dolly supported thereby, a power plunger and a hold-down device, each carried by the frame and movable toward and from the dolly, a lever mounted in the frame and connected to the plunger, power means for operatingthe lever, and means responsive to the movement of the lever for operating the hold-down device.

7. A power operated machine comprising a frame, a dolly supported thereby, a power plunger and a hold-down device, each carried by the frame and movable toward and from the dolly, a power operated piston, means responsive to movement of the piston for moving the holddown device toward the dolly, and mechanism for transmitting power from the piston to the plunger, said mechanism becoming effective automatically at the time that movement of the hold-down device is arrested.

8. A power operated machine according to claim '1 in which the power transmitting mechanism comprises a lever connected to the plunger and adapted to swing, in response to pressure by the piston, about a pivotal support which is adaptedto yield while the hold-down device is free and to be arrested automatically at the same time as said device.

9. A power operated machine according to claim 7 in which the power transmitting mechanism comprises a lever pivoted to the plunger, said lever being actuated by the piston and being mounted upon a floating carrier which becomes stationary in response to arrest of the hold-down device by the dolly.

10. A power operated machine according to claim '7 in which the power transmitting mechanism comprisesa lever pivotally supported by the frame for actuatingthe hold-down device and a second lever pivoted to the first lever for actuating the power plunger, and the power of the pisaton is transmitted to the first lever through the second lever.

11. A power operated machine according to claim 7 in which yielding means are provided for holding the plunger and hold-down device in inoperative position relative to the dolly.

12. A power operated machine comprising a frame, a dolly supported thereby, a plunger mounted in said frame and reciprocable toward and from the dolly, a hold-down device movable toward and from the dolly, a piston for actuating said plunger and hold-down device, means responsive to forward movement of the piston for moving first the hold-down device, then the plunger, toward said dolly, and means for withdrawing first the plunger and then the holddown means on the return stroke of the piston.

13. A power operated machine according to claim 12 in which the withdrawing means comprises springs normally urging the plunger and device upwardly and positive means for forcing the plunger upwardly.

14. A power operated machine according to claim 12, in which the withdrawing means comprises a lever operated by the piston during the return stroke, said lever being connected to the p unger to move the latter positively in both directions.

15. A power operated machine according to claim 12 in which the withdrawing means comprises a lever operated by the piston during the return stroke, said lever being connected to the plunger andadapted to rock about a fulcrum carried by a member connected to the hold-down device whereby said lever positively forces the holddown device downwardly and the plunger upwardly at the same time.

GEORGE T. HARCOURT.

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