US2301817A - Safety device for intermittently operated machinery - Google Patents

Description

Nov. 10, 1942 D. RUSCH 2,301,817

SAFETY DEVICE FOR INTERMITTEN'I'LYOPERATED MACHINERY Filed Feb. 12, 1942 2 Sheets-Sheet 1 will NOV. 10, 1942. RUSCH 2,301,817

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5 i 4 7 h m I 47 l I I I up All my 1: J a a 3 Patented Nov. 10, 1942 SAFETY DEVICE FOR INTERMITTENTLY OPERATED MACHINERY David Busch, Chicago, Ill., assignor to Benjamin Electric Mfg. Company, Des Plaines, 11]., a. corporation of Illinois Application February 12, 1942, Serial No.430,676

12 Claims.

This invention relates to safety devices for intermittently operated machinery and particularly for punch presses, or the like.

In feeding material to punch presses and like intermittently operated machines, it is necessary said moving parts at the time the press is caused to operate, various safety devices have heretofore been proposed. Some of these safety devices employ control levers or handles located in a position of safety and so interconnected, as by rockably secured link arms, that both handlesmust li be depressed in order to trip the clutch mechanism. If but one handle is depressed, the rockably secured link arm will rotate about its center and not trip the clutch.

However, it has been found that prior devices 9 of this character are objectionable, in that, in order to speed up their rate of production, onerators will secure or tie down one of the control handles in a depressed position, so as to permit single-handed operation of the control simply 1:

by depressing the other handle. With such an arrangement, the operator then proceeds to feed the material to the press with the free hand and it is possible for the press to be. tripped while this free hand is in a place of danger. of safety device does not therefore entirely remove the hazard of injury to the operators hands.

To compel the operator to remove his hands to a position of safety and to defeat any attempt on his part to render the safety device ineffective as above indicated, the present invention proposes a tripping mechanism operated by two handles and so constructed that both must be simultaneously depressed before the tripping mechanism may be caused to operate. therefore, an object of the present invention to provide a tamper-proof punch press tripping mechanism which may not readily be altered to This type It is,

permit operation in other than its intended manner. V

The present invention also provides a control unit of simple and compact construction wherein all of the component parts subject to wear, are enclosed in a unitary housing which may beinstalled or removed as a unit.

A further object of the present invention is to provide a punch press trip control embodying a minimum number of parts, which is positive in action and is easy to assemble and maintain.

Other objects and advantages will appear from a consideration of the following detailed specification. For a more complete understanding of this invention, reference may now be had to the drawings, in which:'

Fig. 1 is a side elevation of one embodiment of the present invention;

Fig. 2 is a top plan view of the embodiment illustrated in" Fig. 1; v

Fig. 3 is an enlarged detail vertical sectional View partially in elevation of the safety control unit of the present invention;

Fig. 4 is a horizontal sectional view taken along a line substantially corresponding to line 4-4 of Fig. 3;

Figs. 5, 6 and 7' are changed position views similar to Fig. 3, but somewhat reduced in size;

Fig. 8 is'a detail perspective view of the operating'carriage employed in the'present invention;

Fig. 9 is an enlarged perspective View of one of the slides, two of which are employed; and,

Fig. 10 is a detail perspective view of one of the latch rollers, two of which are employed. Referring to the drawings in detail, the embodiment illustrated comprises spaced operating handles l and 2 which may be mounted on opposite sides of an upright punch press frame 3, in the manner shown in Figs. 1 and 2. These operating handles may be supported upon a common connecting shaft 4.

Handle I may be securely afiixed to shaft 4 by means of locking cap screw 5. The handle 2 is rotatably mounted on horizontal shaft 4 at the end opposite the handle I and kept from slipping longitudinally off the end of the shaft by means of a washer and cotter pin arrangement 5. A short arm 1 may also be firmly secured to the shaft 4-adjacent handle 2, as by a suitable looking cap screw 8, so that downward manipulation of handle I will cause a corresponding movement of arm 1.

The outer end of the short arm 1 is provided with a nut 9 which is pivotally mounted thereon and engages the threaded lower end of an adjustable link 10. A similar nut H is intermediately located on the handle 2 and engages the threaded lower end of a similar link l2.

With the above arrangement, it will be apparent that downward movement of the handle I causes rotation of shaft 4 and a corresponding downward movement of short arm I, with the result that link In is drawn downwardly. Similar downward movement of handle 2 causes link 12 to move downwardly. Both links and their connected handles are normally retained in an upward position by resilient means hereinafter de scribed.

The details of the control unit are shown in Figs. 3 to inclusive. This unit includes a rear base plate l3, a housing member I4 and a front cover platel5. The rear base plate [3 is provided with lugs [6 through an opening in which suitable fastening screws may extend to secure the unit to the side of a punch press frame, or the like. This rear base plate is also provided with opposed projections I1 and I8 of reduced thickness and having arcuate slots l9 and 20, respectively. The projections I 'l and [8 being of reduced thickness are somewhat spaced from the rear surface of the rear base plate I3 to .provide room for bolt fastening means as shown.

The housing member M is preferably in the form of an inverted U to provide a top portion 2'! and opposed depending leg portions 22 and 23. To this is affixed an outer cover member [5 which is peripherally shaped to conform to the outer surface of the housing member. The cover member l3 and the housing member I 4 have oppositely disposed lugs 24 and 24a to accommodate fastening bolts 25. These bolts 25 may extend through the arcuate slots 19 and 23 and be secured in place by nuts 25a. This permits the entire unit to be bodily adjusted about its central axis and then securely locked in a selected position.

The rectangular inner area of the above housing is defined by vertical-side walls and is adapted" to accommodate and guide a vertically reciprocatable carriage 26 'shown'in'detailin Fig. 8. This carriage 26 comprises a central support bar 2! having an upstanding threaded portion 28 which may extend through an opening 29 in the top 2| of "the housing I 4. This carriage has a frame, preferably formed of sheet metal sections 33 and 3| which are secured together and to the centralsupport bar by means of spaced rivets 32 extending therethrough.

The entire carriage, including the central support bar, upwardly extending threaded shaft and the stamped sections is a single member.

The spaced axially extending openings left in the carriage on each side of the central supporting bar 21 accommodate opposed slide blocks 33 shown in detail inFig. 9. Two of these slide blocks are used in the present invention and are a sliding fit within the carriage. They are separately operable for vertical sliding movement in these openings. Each comprises an elongated member having a ratchet-receiving recess 34 adjacent its upper end which is shaped to accommodate a flat ratchet plate 35. This plate is rounded at both ends and adapted to be inserted into the ratchet opening for limited movement therein. The ratchet plate is preferably formed of hardened material more readily to resistwear.

A pair of resilient compression springs 36 are mounted under each ratchet plate and bear thereon. to resiliently retain the plate in an upward position in its slot. Retaining pins 31 are provided oneach slide block adjacent the outer end of the ratchet plate and serve to prevent plate during-ratchetoperatiOn thereof. Each of the slide blocks 33 is also provided with latch races 33 and 39, the course of each of which is interrupted by said ratchet plate 35.

In assembly, the slide blocks are placed in the carriage with the ratchet plates each facing the central support bar 21 for vertical sliding movement in their respective apertures.

The central supporting bar is provided with recesses 43 and 4| disposed on opposite sides thereof and in which are located latch rollers 32-42. When assembled, these latch rollers lie opposite the races 38 and 39.

With the unit assembled, ratchet-retaining bolts 53 and 34 may be inserted through suitable openings 33, 45a in the top 2! of the body portion M and springs 36-43 may be placed about each bolt to bear against the inner top surface of the block and resiliently retain it in an upward position. The compression of the springs is adjustable by rotation of retaining bolts 43 and 6 2 to vary the position of nuts 41 thereon.

The upwardly extending threaded portion 28 ofthe carriage passes through opening 29 in the housing and the entire carriage is resiliently retained in place by means of a coil spring 48. This shaft 28 may be secured by any suitable means, as by the adjustable link 49 to the clutch mechanism trip lever 53, operation of which causes the trip of the punch press to release the clutch and permit operation of the press.

In operation, with the control unit instahed on a punch press as indicated above and with the press ready to operate, the operator first places his hands, one on each of the handles i and 2, and simultaneously moves these handles downwardly. This causes links Ill and I2 with connected ratchet slides 33 to also move downwardly and the ratchets of these slides engage the latch rollers 42, so that carriage 26 is moved downwith the ratchets. Through threaded stem 23, link 50 is thus moved downwardly to trip the press. Fig. 6 indicates the relative position of the parts during such downward movement, the direction of movement of the parts being shown by arrows.

Obviously wtih the above arrangement, the operators hands must be out of the path of the machines movement before the press is tripped. Should the operator fail to press both handles, then the parts assume the relative position indicated in Fig. 5 where one of the ratchet slide blocks 33 is shown moved downwardly and the latchroller 42 is shown laterally displaced into the race 39 to evade the ratchet plate 35 whereby the carriage 25 remains stationary. The latch rollers would likewise be displaced in the opposite direction upon downward movement of the opposite ratchet slide block.

The above result could perhaps be achieved with a ratchet block assembly which would not include resilient means for urging the ratchet plate upwardly in its notch. However, in order to permit return of the slide blocks to their uppermost position after the trip has once been operated, it is necessary to provide means whereby the ratchet plates may be permitted toyield and move around the latch rollers during their upward return movement. This is accomplished in the present embodiment by the provision of springs 36, one set of which is shown compressed in Fig. 7, so that ratchet plate 35 may move upwardly beyond the latch rollers 42.

Any attempt to fasten one of the handles in a downward position and manipulate the control by one hand while feeding the press with the remaining free hand would be of no avail, inasmuch as simultaneous downward movement of both handles is required to trip the press. With one handle secured downwardly, manipulation of the other handle would merely cause lateral displacement of the latch rollers without any corresponding downward movement of the carriage.

While particular embodiments of the invention have been shown, it will be understood, of course, that it is not desired that the invention be limited thereto since modifications may be made, and it is, therefore, contemplated by the appended claims to cover any such modifications as fall within the true spirit and scope of the invention.

Having thus described the invention, what is claimed and desired to be secured by Letters Patent is:

1. A clutch controlling device comprising a longitudinally movable carriage, laterally displaceable means supported on said carriage for actuation thereof, and oppositely disposed ratchet members for simultaneously engaging said laterally displaceable means to actuate said carriage, said ratchet members being ineffective to move said carriage except during simultaneous movement of said ratchet members, neither of said ratchet members being effective to move said carriage when the other ratchet member is in the position to which it is moved in its normal actuating movement.

2. A safety control for punch presses and the like comprising a housing, a carriage slidably mounted in said housingfor operating connection to the usual clutch tripping mechanism of a press, independently operable ratchet members slidably fitted in said carriage, and common latch means supported on said carriage for actuation thereof and engageable by simultaneous movement of said ratchet members, said ratchet members bein so related to said common latch means that simultaneous movement thereof causes 5 movement of said carriage while other than simultaneous movement causes displacement of said common latch means to free said ratchet members therefrom, neither of said ratchet members being effective to move said carriage when the other ratchet member is in the position to which it is moved in its normal actuating movement.

3. A control mechanism for operation of a clutch tripping device comprising a movable carriage effective upon bodily movement to trip said clutch, a displaceable force-transmitting means associated with said carriage, and independently operable means to actuate said carriage through said force-transmitting means upon simultaneous movement of said independently operable means, said force-transmitting means serving to prevent movement of said carriage by said independently operable means when movement of said independently operable means is not simultaneous, neither of said independently operable means being effective to move said carriage when the other independently operable means is in the position to which it is moved in its normal actuating movement.

4. In a punch press trip mechanism wherein simultaneous movement of two operating levers is a prerequisite to tripping action, the combination with a movable trip member for tripping the clutch of a press, of a carriage connected to said movable member, a latch mounted on said carriage, and opposed ratchet members having resiliently mounted latch-engaging portions to engage said latch so that simultaneous downward movement of said ratchet members moves said latch and said carriage to trip said movable trip member but independent movement of either of said ratchet members causes displacement of said latch and disengages said carriage from said ratchet members, neither of saidratchet members being effective to move said carriage when the other ratchet member is in the position to which it is moved in its normal actuating movement.

5. In a punch press trip operating mechanism, a movable member for trippin the clutch of a press, a carriage connected to saidmovable member, latch means mounted for lateral movement in said carriage, spaced independently operable latch-engaging members disposed on opposite sides thereof, and operating handles linked to said latch-engaging members whereby simultaneous downward movement of both of said handles causes downward press tripping movement of said carriage while individual movement of said handles causes lateral displacement of said latch to remove it from operating engagement with said members, neither of said latch-engaging members being effective to move said carriage when the other latch-engaging member is in the position to which it 1s moved in its normal actuating movement,

6. A control mechanism for tripping the clutch of a punch press comprising an actuated member whose movement causes operation of the press, spaced co-operating independently movable actuating members for controlling the movement of said actuated member, force-transmitting means mounted upon said actuated member and laterally displaceable thereon, said force-transmitting means being disposed between said spaced actuating members and capable of force-transmitting co-operation therewith for movement of said actuated means upon simultaneous similar movement of said actuating means, neither of said actuating means being effective to move said carriage when the other actuating means is in the position to which it is moved in its normal actuating movement.

7. A trip mechanism for controlling the tripping of a press comprising an actuated member whose advance movement causes operation of the press, two co-operating independently movable actuating members for controlling the movement of said actuated member, movement-directing means for mounting said actuated member for advance movement efiective to trip the press and for lateral movement ineffective to trip the press, and movement-directing means for mounting each of said actuating members for effecting lateral movement of said actuated member ineiiective to trip the press when only one of said actuated members is operated and for effecting advance movement of said actuated member effective to trip the press when both said actuating members are operated simultaneously, neither of said actuating members being effective to move said carriage when the other actuating member is in the position to which it is moved in its normal actuating movement.

8. A guide, a carriage movable in said guide, latch means movably mounted on said carriage for movement transversely of the movement of the carriage, two manually operable independently movable actuating members reciprocably mounted on said carriage for movement longitudinally of the carriage movement and engageable with said latch means to exert opposing force components thereon transverse to the movement of the carriage and. also concurrent force components thereon longitudinally of the movement of the carriage whereby when said actuatin means are moved to act simultaneously on the latch means the transverse components will latch the carriage to both actuating means and the longitudinal components will cause movement of the carriage and whereby when one of said actuating members acts in advance of the other the latch means will be moved to nonlatching position with respect to said advance actuating member, neither of said actuating members being effective to move said carriage when the other actuating member is in the position to which it is moved in its normal actuating movement.

9. A guide, a carriage movable in said guide, latch means movably mounted on said carriage for movement transversely of the movement of the carriage, two manually operable independ ently movable actuating members reciprocably mounted on said carriage for movement longitudinally of the carriage movement and engageable with said latch means to exert opposing force components thereon transverse to 'the movement of the carriage and also concurrent force components thereon longitudinally of the movement of the carriage whereby when said actuating means are moved to act simultaneously on the latch means the transverse components will latch the carriage to both actuating means and the longitudinal components will cause movement of the carriage and whereby when one of said actuating members acts in advance of the other the latch means will be moved to nonlatching position with. respect to said advance actuating member, said actuating members being latchable with respect to said latch means in only one direction of reciprocation of said actuating members on said carriage, neither of said actuatingmembers being efiective to move said carriage when the other actuating member is in the position to which it is moved in its normal actuating movement.

10. A ratchet actuating member for a safety punch press control device or the like comprising, an elongated member having an opening extending into its interior, and a ratchet receiving notch adjacent one end, a ratchet the end of which seats and pivots in the bottom of said notch, resilient means for normally urging said ratchet to one side of said notch, and a ratchet retaining peg extending transversely of the swinging end of the ratchet to retain said ratchet in place when it is moved to the opposite side or" said notch.

11. An actuating member for a safety punch press trip control comprising an elongated slide block having grooves in one surface thereof, a wedge-shaped notch intersecting said grooves, a latch engaging ratchet member movably secured said notch, and resilient means to urge said ratchet member to one side of said notch whereby a latch may be actuated by movement of said actuating slide block in one direction and may be released through said resilient means upon movement of said slide block in the opposite direction.

12. Means for actuating a safety punch press trip control device comprising a guide block, an elongated slide block reciprocably mounted thereon, said slide block having an opening extending longitudinally of its movement, means for yieldingly securing said slide block to said guide block comprising an anchor bolt extending into said opening and a spring in said opening surrounding said bolt, said slide block having a notch in one side thereof, a ratchet member pivotally mounted in said notch, and resilient means urging said ratchet member toward one side of the notch.

DAVID RUSCI-I.

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