US2049990A - Safety guard for foot presses - Google Patents

Description

- Aug. 4, 1936. I c. G. ARMSTRONG 2,049,990

I SAFETY GUARD FOR FOOT PRESSES Filed Nov. 5, 1934 2 Sheets-Sheet l I ll l I 20 INVENTOR a 1 18! BgllffordtiArmstr'onqi 1m fi. %%M

' Arnfi w g- 1936- c. G. ARM'STRO'NG 49,990

SAFETY GUARD FOR FOOT PRESSES Filed Nov. 5, 1934 '2 Shets-Sheet 2 5 &9 4 2 i 411, ,5-

IN VEN TOR Clzffort/GA rmstrong ATTO EY Patented Aug. 4, 1 936 PATENT OFFICE SAFETY .GUARD FOR FOOT PRESSES Clifiord G. Armstrong, Meriden, Conn; Luella B. Armstrong'executrix .of said Clifford G.

Armstrong, deceased Application'November 5, 1934,-:Serial No. 751,567

1'7 Claims.

This invention relates to safety devices, and more particularly to a safety guard device adapted to be applied to a foot-press to prevent injury to the hands of the operator.

One object of this invention is to provide a safety guard device of the above naturewhich may be readily attached to a footpress in front of the punch'carrying ram, and which will instantly lock the punch'in its downwardmovement in case the operators hand accidently gets into the path of the guard.

A further object is to provide a safety guard member of the above nature which is adapted to travel faster and in advance of the punch carrying ram, and which upon contacting with the operators hand or other obstacle will instantly slide a transverse bolt into engagement with the ram to positively prevent the punch from completing its downward stroke.

A further object is to provide a safety guard device of the above nature which will be positively actuated by a suitable linkage mechanism associated with the guard member.

1 A further object is to provide a safety guard device of the above nature which'will be comparatively simple in construction, inexpensive to manufacture, easy to install and manipulate, compact, and very efficient and durable in use.

With these and other objects in view, there has been illustrated on the accompanying drawings, one form in which the invention may be conveniently embodied in practice.

In the drawings:

Fig. 1 represents a front elevational view of the safety guard device as it appears'when installed upon a foot-press with the punch carryingram in its uppermost position.

Fig. -2'is a top plan view of the same.

Fig. 3 is a right-hand side view of the locking mechanism and a fragmentary portion of the foot-press. Fig. 4 is a view similar to Fig. 1, showing the appearance of the safety guard attachment when the guard member is obstructed by the operators hand, and with the transverse bolt in looking position.

Fig. 5 is a perspective view of the ram locking bolt and its associated actuating link.

Referring now to the drawings in which like reference numerals denote corresponding parts throughout the several views, the numeral lil indicates the frame of an ordinary type of footpress, which is provided with the usual vertical reciprocating ram ll carrying a punch Ila upon its lower end. The ram H is mounted to slide in the frame-by means of guide-Ways l2 and I3, and is adapted to be driven by a foot-operated lever l4 having at its upper end an integral circular cam head l5 engaging in a rectangular slot It provided in the intermediate body of the ram 5 II. The lever I4 is pivotally connected to the frame it :as by a pin I1, and is adapted'to be operated by means of a treadle (not shown) located underneath the supporting bench.

In order to prevent accidental injury to the hands of the operator by thepunch Ha, provision is made of a safety guard member I8 in the form of a relatively narrow horizontal bar, and supported in front'of the raml lupon the lower end of a vertical rod i9 located at one side of the punch Ila. The rod I9 is adjustably attached to a sliding plate by means of a pair of eye bolts 2| and nuts 2Ia.

The sliding plate 20 is loosely connected with the lower end of an elongated vertical main sup- 0 port bar 22. This is accomplished by means of a pair of headed pins 23 extending forwardly'from said plate 20 and. having loose slidable engagement in an elongated slot 24 formed in the lower end of said bar 22.

The main bar ;22 is adapted to have vertical reciprocating movement within a pair of guide brackets .25 and 26 secured to a traveling block 2! at the upper and lower ends thereof. The traveling block 21 is permanently connected .to the frontface of the ram II as by means of machine screws 28, and said block servesas a support for a horizontally sliding catch or locking bolt 29. For this purpose the block 21 is provided with a horizontal groove .30 in itsforward face for guiding said lockingbolt 29, whichisretained in: said grooveby means of a verticalrmetal strap 3i securedto the face of the traveling block 21, as by bolts. The left-hand end. of the locking bolt 29, as viewed in Figs. 1, 4, .and. 5, is provided with a series of buttress teeth 32 which are adapted to engage with an elongatedset. of similar opposed buttress teeth 33 of the samepitch located on the right-hand or inner side-of a rack 34 permanently secured to'the front face .of the left-hand ram guide-way, as by-meansof screws-35.

In order to actuate the .transverse locking bolt 29, provision is made of a vertical link bar 36 located on the face of said .bolt between a pair of opposed headed guide pins 31, carried by said bolt 39 tsee Fig. 5). The bolt actuating link bar 36 is slidably engaged in longitudinal guide slots 36a provided in the guidebrackets and26 (see Fig. 2), andsaid link 36 is supported and-connected at-its upper and lower ends, respectively, to the ram main bar 22 by means of a parallel swinging arm 38 and a lever 39, having pivoted connection both to said bar 22 and said actuating link 36 by bolts 38a and 390,, respectively. The lower lever 39 extends beyond the central pivot bolt 39a. and is connected at its lower end to a short link 48 which in turn is connected to the rear face of the sliding plate 20 by means of a pin 400.

To cause the guard member I8 to be moved downwardly faster than and in advance of the punch Ila, provision is made of a T-shaped cam lever 4| pivotally mounted upon the forward face of a support plate 42 by means of a pivot stud 4| a, the latter engaging in an elongated slot 4|b provided in the body of said cam lever 4|. The plate 42 is rigidly secured on the upper 'end of a bracket 43 adjustably attached to the forward face of the rack 34 by means of a pair of binding screws 44.

The cam lever 4| comprises a substantially triangular shaped body 45 and a laterally extending arm 46. The body 45 is provided with a downwardly extending slot 41 connected at its lefthand side with an arcuate lateral slot 48. A pair of cam slot studs 49 and 58 projecting forwardly from the strap plate 3| are adapted to engage in said downwardly extending and arcuate slots 41 and 48, respectively.

In the normal inactive position of the locking device, the upper stud 49 will be located at the upper end of the downwardly extending slot 47 and the lower stud will be positioned in the arcuate slot 48. The arm 46 is resiliently connected at its outer free end to an L-shaped connecting rod 5| pivoted at its upper end 5| a to the main bar 22. The resilient connection between the arm 46 and the L-shaped rod 5| is accomplished by means of an eye stud 52 swivelly connected to the arm 46 and slidably embracing the lower portion of the connecting rod 5|. Below the eye stud 52, the rod 5| is surrounded by a helical compression spring 53, the lower end of said spring being held in place by means of a washer 53a and a cotter pin 53b. The swiveling eye 52 stud is limited in its up-stroke on the connecting rod 5| by means of a collar 5|b securely aflixed at an intermediate position thereupon.

It is to be noted at this point that when the ram H starts on its downward movement, the lower stud 50 carried by the strap plate 3|,..and which operates in the arcuate slot 48, will cause the cam lever 4| to pivot about its supporting screw 4| a in a clockwise direction. The extending arm 46 of the T-shaped lever 4| will then cause the main bar 22 and the associated linkage to be carried downwardly at a speed approximately ten times as fast as the movement of the II. When the T-shaped cam lever 4| is swung to a substantially horizontal position, as indicated in the dotted line in Fig. 1, the downwardly extending slot 41 of the cam body 45 will be in a substantially vertical position, and the lower stud 58 will have passed out of the arcuate slot 48, and will lie within the slot 41. The cam lever 4| will, however, be prevented from rotating farther in a clockwise direction beyond the horizontal position indicated by the dotted line in Fig. 1 by means of a pair of stop pins 54 attached to the upper left-hand corner of thesupport plate 42.

In order to assist in restoring the ram and attached parts to their normal inactive or uppermost positions subsequent to the stamping operation, provision is made of a relatively heavy helical compression spring 55 surrounding a vertical elongated guide rod 56 located at the left of the rack 34 and rigidly supported at its upper end to an angle bracket 5'! permanently secured to the upper edge of the traveling block 21. The lower end of the guide rod 56 is slidably guided within an aperture in a horizontal bracket 58 pivoted or otherwise secured to the lower end of the rack 34. The bracket 58 also serves to support the lower end of the spring 55 thereupon, the upper end of said spring being abutted against a collar 59 having slidable adjustable engagement on said guide 56. The collar 59 is adapted to be held in adjusted position by means of a set-screw 60.

Operation In operation, when the operator presses upon the foot lever I4, the punch carrying ram II will move downwardly, and the action of the lower stud 50 and gravity will swing the T-shaped cam lever 4| in a clockwise direction to the position shown in dotted lines in Fig. 1. This operation will obviously cause the main bar 22, the parallel link 36, and associated parts to be moved more" rapidly downwardly, causing the protecting guard I8 to travel from the position shown in Fig. 1 to within approximately a quarter of an inch from the top of the press bed plate |a.. During the normal operation of the machine, the distance between the bar 22 and link 36 will remain unchanged during the reciprocating vertical strokes of the punch carrying ram. In case, however, the operator should accidentally place his hand in the path of the protecting guard l8 (which travels in advance of the punch H a) the downward motion of the plate 28 with respect to the main bar 22 will be arrested, and by reason of the arrangement of the connecting linkage, the boltactuating link 36 will be moved to the left, forcing the locking bolt 29 to the left, bringing its teeth 32 into interlocking engagement with the teeth 33 on the rack 34. The downward travel of the punch carrying ram II will thereby be instantly stopped and possible injury to the operator prevented.

Owing to the mechanical advantage and freedom of movement of the parts, only a slight pressure of the guard |8 against the operators hand is required to slide the bolt 29 and lock the ram While there has been disclosed in this specification one form in which the invention may be embodied, it is to be understood that this form is shown for the purpose of illustration only, and that the invention is not to be limited to the specific disclosure but may be modified and embodied in various other forms without departing from its spirit. In short, the invention includes all the modifications and embodiments coming within the scope of the following claims.

Having thus fully described the invention, what is claimed as new, and for which it is desired to secure Letters Patent, is:

. 1. In a safety device for a foot-press having a sliding ram, a block carried by said ram, a locking bolt slidably mounted in said block, a rack secured to the frame of the press in the path of said bolt, a vertical bar slidably mounted in said block, a guard having longitudinal slidable engagement with the lower end of said bar, and linkage means carried by said bar and associated with said'bolt and said guard, whereby said bolt will be caused to mesh with said rack whenever the downward movement of said guard is obstructed, said guard having a high mechanical advantage with respect to said vertical bolt actuating bar. s

2. In a safety device fora foot presshaving-a sliding ram, a block carried by said ram, a looking bolt slidably-mounted on said block, a rack securedto the frameof the :press in the pathof said bolt, a vertical bar slidably mounted in said block, a guard having longitudinal slidable engagement with the lower end of said bar, and parallel linkage means carried by said bar and associated with said bolt and said guard, whereby said bolt will be caused to mesh with saidrack whenever the downwardmovementof said guard is obstructed, said guard having a high mechanical advantagewith respect to said vertical bolt actuating bar.

-3. In a safety device for a foot-press having a sliding ram, a block carried by said ram, a locking bolt slidably mounted-in said block, arack secured to the frame of the press in the path of said bolt, a vertical bar slidably mounted in said block, a guard having longitudinal slidable engagement with the lower end of said bar, linkage means carried by said bar and associated with said bolt and said guard, whereby said bolt will be caused to mesh with said rack whenever the downward movement of said guard is obstructed, and leverage means associated with said moving ram and connected to said vertical bar to cause said bar to operate at a greater speed and mechanical advantage than said ram.

4. In a safety device for attachment to a footpress having a frame in which is a vertically sliding rain, a transverse bolt slidably mounted with respect to said ram, a rack secured to said frame in the path of said bolt for interlocking therewith, a vertically movable bar, a guard member slidably connected to said bar, means pivoted to said frame and connected to said bar for causing said bar and guard to move at a speed greater than said ram, and mechanism carried by said bar and directly connected to said bolt for positively sliding said bolt into and out of engagement with said rack whenever the downward movement of said guard member is obstructed by even a very slight force.

5. In a safety device for attachment to a footpress having a frame in which is a vertically sliding ram, a transverse bolt slidably mounted with respect to said ram, a toothed rack secured to said frame in the path of said bolt for interlocking therewith, a vertically movable bar, a guard member slidably connected to said bar, means pivoted to said frame and connected to" said bar for causing said bar and guard to move at a speed greater than said ram, and mechanism carried by said bar and directly connected to said bolt for positively sliding said bolt into and out of engagement with said rack whenever the downward movement of said guard member is obstructed by even a very slight force.

6. In a safety device for attachment to a footpress having a frame in which is a vertically sliding ram, a transverse toothed bolt slidably mounted with respect to said ram, a toothed rack secured to said frame in the path of said bolt for interlocking therewith, a vertically movable bar, a guard member slidably connected to said bar, means pivoted to said frame and connected to said bar for causing said bar and guard to move at a speed greater than said ram, and mechanism carried by said bar and directly connected to said bolt for positively sliding said bolt into and out of engagement with said rack whenever the downward movement of said. guard mem-V beris obstructed by even a very slight force. I

7. In a safety device for attachment .to a footpress having a frame in which is a vertically sliding ram, a transverse bolt slidably mounted with 15 respect to said ram, a rack secured to said frame in the path of said bolt for interlocking therewith, a vertically movable bar,a guard member slidably connected to said bar, means pivoted to said frame and connected to said bar for causing said bar and guard to mo-velat a speed and mechanical advantage greater than said ram, and mechanism carried by said bar and directly connected to said bolt for positively sliding said bolt into and out of engagement with said'rack whenever the downward movement of said guard member is obstructed, and means connected to said frame and associated with said ram tending to compensate for the excess weight of the safety device. 20:

8. In a safety device for a press having a frame carrying a sliding ram, a transverse bolt slidably mounted on said ram, a vertical rack secured to said frame for interlocking engagement with said bolt, a vertical main bar having a guard member loosely connected to said main bar, a supplemental bar slidably connected with said bolt parallel to said main bar, laterally spreading linkage mechanism for connecting said supplemental bar to said main bar and said guard member, and leverage means pivoted to said rack and associated with said ram for causing said guard to move downwardly in advance of and at aspeed and mechanical advantage greater than said ram, whereby said bolt will be moved into interlocking engagement with said rack whenever the downward movement of said guard member is obstructed,

9. In a safety device for'attachment to a footpress having a supporting frame in which is a punch carrying ram, a laterally movable bolt mounted in said frame, means on said frame for interlocking with said bolt, a vertically movable main bar, means connected with said ram and said main bar for causing said main bar to travel downwardly in advance of said ram, a guard carried by the lower end of said main bar, a supplemental bar connected with said bolt, and parallel linkage means for connecting said bars, and means connected with said guard member for operating said linkage and supplemental bar to move said bolt into interlocking engagement with said rack, said guard having a high mechanical advantage with respect to said vertical bolt actuating bar.

10. In a safety device for attachment to a footpr-ess having a frame carrying a sliding ram, a rack secured to said frame, a bolt mounted to move transversely with respect to said ram into interlocking engagement with said rack, an elongated vertical main bar, a guard member slidably connected to the lower end of saidmain bar, parallel linkage means carried by said bar and connected with said bolt and "said guard, whereby said bolt will be responsive to the movement of said guard, and means connected with said ram for forcing said main bar downwardly in advance of said ram, said bolt being caused to interlock with said rack to suddenly stop the downward movement of said ram whenever the downward movement of said guard member is obstructed, said guard having a high mechanical advantage with respect to said vertical bolt actuating bar.

11. In a safety device for attachment to a foot- 75 press having a frame carrying a sliding ram, a rack secured to said frame, a bolt mounted to move transversely with respect to said ram into interlocking engagement with said rack, an elongated vertical main bar, a guard member loosely connected to the lower end of said main bar, parallel linkage means carried by said bar and connected with said bolt and said guard, whereby said bolt will be responsive to the movement of said guard, a swinging l-ev-er pivotally connected with said rack and associated with said ram, and a link connecting one end of said lever with said bar, said bolt being caused to interlock with said rack to suddenly stop the downward movement of said ram whenever the downward movement of said guard member is obstructed, said guard having a high mechanical advantage with respect to said vertical bolt actuating bar.

12. In a safety device for attachment to a foot press having a frame carrying a sliding ram, a rack secured to said frame, a bolt mounted to move transversely with respect to said ram into interlocking engagement with said rack, an elongated vertical main bar, a guard member slidable in the lower end of said main bar, parallel linkage means carried by said bar and connected with said bolt and said guard, whereby said bolt will be responsive to the movement of said guard, a lever pivotally mounted with respect to said frame and having a slot and stud connected with said ram, said bolt being caused to interlock with said rack to suddenly stop the downward movement of said ram whenever the downward movement of said guard member is obstructed, said guard having a high mechanical advantage with respect to said vertical bolt actuating bar.

13. In a safety device for attachment to a footpress having a frame carrying a sliding ram, a rack secured to said frame, a bolt mounted to move transversely with respect to said ram into interlocking engagement with said rack, an elongated vertical main bar, a guard member slidably connected to the lower end of said main bar, parallel linkage means carried by said bar and connect-ed with said bolt and said guard, whereby said bolt will be responsive to the movement of said guard, a lever pivotally mounted with respect to said frame and having a slot and stud connected with said ram, said bolt being caused to interlock with said rack to suddenly stop the downward movement of said ram whenever the downward movement of said guard member is obstructed by even a slight force, said lever having a pin and slot connection with said ram, and a link for connecting the free end of said lever with said main bar.

14. In a safety device for attachment to a footpress having a sliding ram, a block secured to said ram, a bolt mounted to slide transversely in said block, a catch secured to the frame of said press and having interlocking engagement with said sliding bolt, a vertical main bar having slidably engagement with said block, a sliding plate having pin and slot connection with the lower end of said bar, a guard member connected to said plate, parallel linkage means pivotally connected to said bar and said plate and connected with said bolt, whereby said bolt will be directly responsive to the obstruction of said guard, and means responsive to the movement of said ram for moving said main bar downwardly in advance of said ram, said guard having a high mechanical advantage with respect to said vertical bolt, actuating bar.

15. In a safety device for attachment to a footpress having a sliding ram, a block secured to said ram, a bolt mounted to slide transversely in said block, a catch secured to the frame of said press and having interlocking engagement with said sliding bolt, a vertical main bar having slidable engagement with said block, a sliding plate having pin and slot connection with the lower end of said bar, a guard member con-' nected to said plate, parallel linkage means pivotally connected to said bar and said plate and connected with said bolt, whereby said bolt will be directly responsive to the obstruction of said guard, and means resiliently connected to said main bar responsive to the movement of said ram for moving said main bar downwardly in advance of said ram, said guard having a high mechanical advantage with respect to said vertical bolt actuating bar.

16. In a safety device for attachment to a footpress having a sliding ram, a block secured to said ram, a bolt mounted to slide transversely in said block, a catch secured to the frame of said press and having interlocking engagement with said sliding bolt, a vertical main bar having slidable engagement with, said block, a sliding plate having pin and slot connection with the lower end of said bar, a guard member connected to said plate, parallel linkage means pivotally connected to said bar and said plate and connected with said bolt, whereby said bolt will be directly responsive tothe obstruction of said guard, and a lever resiliently connected to said main bar, a link pivoted to said main bar and slidable in the free end of said lever, and spring means between the ends of said lever and said link to cushion the impact of said guard member upon any obstruction in the path thereof, said guard having a high mechanical advantage'with respect to said vertical bolt actuating bar.

17. In a safety device for a foot-press having a sliding ram, a block carried by said ram, a locking bolt slidably mounted on said block, a rack secured to the frame of the press'in the path of said bolt, a vertical bar slidably mounted in said block, a guard having'longitudinal slidable engagement with the lower end of said bar, and linkage means carried by said bar and associated with said bolt and said guard, the movement of said bolt both'into and out of locking position being responsive to the movement of said guard, said guard having a high mechanical advantage with respect to said vertical bolt actuating bar.

CLIFFORD G. ARMSTRONG.

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