US2582023A - Safety guard for presses - Google Patents

Description

Jan. 8, 1952 R R FERRER 2,582,023

SAFETY GUARD FOR PRES-SES l y Imventor E @Mmmm Gttomegs Jn- 8, 195/2 E. R. FERRER 2,582,023

SAFETY 'GUARD FOR PRESSES Filed Dec. 29, 1949 4 sheets-sheet 2 Gttornegs Jan. 8, 195.2 E. R. FERRER SAFETY GUARD FOR PRESSES 4 Sheets-Sheet 3 Filed Deo.l 29, 1949 Snventor Gttornegs Jan. 8, 1952 Filed Deo. 29, 1949 E. R. FERRER 2,582,023

SAFETYV GUARDl FOR PRESSES I 4 .Sheets-Sheet 4 I Snventor (Ittmegs Patented Jan. 8, 1952 SAFETY GUARD FOR PRESSES Edwin R. Ferrer, Fairfield, Conn., assignor to The Bassick Company, Bridgeport, Conn., a corporation of Connecticut Application December 29, 1949, Serial No. 135,729

14 Claims.

This invention relates to safety guards for presses, and it has particular reference to guard devices for presses in which the work'is placed in position in a die before being operated upon by a descending punch or plunger. The invention also has special reference to those devices having moving means for removing the hand or hands of the operator from the path of the descending punch.

Numerous devices of this general class have been proposed heretofore, but, so far as I am advised, all have been open to serious defects and disadvantages, and oneof the objects of this invention is to provide an improved structure which will obviate these defects and disadvantages.

Another object is to provide a simple and relatively inexpensive structurefor the purpose in view which is very sure and certain inoperation.

Another object is to provide a device of this classvin which there are no moving parts to obstruct the operators view of the die, and in which the operators hands, while under the control of flexible members attached to the` operator-s wrists, have very considerable freedom of movement, except at the time the punch is descending and is close to the hands, at which time the operators hand, if in the danger zone, will be removed therefrom in a sure and effective manner.

Another purpose of theinvention is to provide an improved mechanism of this type in which the moving guard device or devices are not in continuous operation, but on the other hand are operated only in case of emergency, thus decreasing the maintenance cost of the device.

In the accompanying drawings:

Fig, 1 is a front elevation of a press equipped' with a safety guard embodying the invention, the punch carried by the press gate and the die being omitted;

Fig. 2 is a side elevation of the device shown in Fig. 1, the guard device being shown ina nonemergency position, the press gate being in its uppermost position, the lowermost position of the gate being shown in dotted lines;

Fig. 3 is a top plan view of the device:y

Fig. 4 is a view similar to Fig. 2, the guard device being shown in the position which it as-y sumes just before the operators hand is moved automatically out of the danger zone;

Fig. 5 is a section on line 5-5 of Fig. 3:

Fig. 6 is a sectional view showing a modified form of device; and

Fig. 7 is a sectional view showing a further modified form. A1

In the device selected for illustration in Figs. l to 5, inclusive, the press is of the type in lwhich the punch or plunger is carried by a gate or ram actuated by a shaft having a crank connected to the gate or ram by means of a connecting4 rod or pitman. The connecting rod head that is connected to the crank portion of the operating shaft is equipped with a forwardly projecting members co-acting with a tonguesshapedg cam fixed to a rock shaft mounted'in bearings supported by brackets from thev press 'frame' adjacent the front face of the frame. l shaft has connected thereto a pairA of swinging arms the upper ends of which vare suitably fas tened to the shaft, the lower ends of said arms4 being connected by flexible members with `wristlets attached to the wrists'` of the operator, the arrangement being such that the operators hands are permitted considerable freedom and all necessary movement in feeding the -Work to the press' and removing it therefrom, although,v if the operators hand is in the path of the ram', the

projection on the connecting rod head, in con-v junction with the tongue-shaped cam on the'rocki shaft, will act in such a manner as to swingthe depending arms, and therebyl the operators'l Their forward and rearward movement is undervv the guidance of forwardly extending guide elements in the form of bars generally lhorizontally, disposed and having ends adjacent the` press. frame that are fastened to the press frame for' swiveling movement, as hereinafter described. These bars are at the inner sides of the swinging arms, and the swinging arms are arranged to make vcontact therewith so that the 'arms are guided and are held separatedv at a minimum distance.. In the drawings, the press frame isindicated at I0, the press bed at I I, the ram or gate at I2,

the connecting rod at I3, the connectingrod head at I4, the driving shaft at I5, andthe crank to which the head I4 is connected, at'4 I6TIA iThe rock shaft, previously mentioned, is' indicated' at" I'I, the brackets which mount the lrock shaft from the forward face of the press frame at I8, the depending swinging arms fastened at their upper ends to the rock shaft, at I9, the forwardly projecting guide bars at 2U, the wristlets adapted to be' fastened to the wrists of the operator, at 2l, and the flexible members (shown as chains) connecting the wristlets to the lower ends of the arms I9, at 22. In the present oase, a single spring 23, connected at one end. to a part on the rock shaft anld'at the other end Jto the left-hand bracket I8 (Fig. 1), holds each of the swinging arms normally in the position shown in Fig. 2.

The punch carried by the press gate and the tool block or die-holding block withwhich the punch cooperates are shown in Fig. 2, but are omitted in the other views.. The connection of the connecting rod to the press gate or ram is not shown in detail, but it is understood that the lower end of the connecting rod Ahas ,proper pivotal connection with the ram or gate.

In the embodiment shown, there are two mounting brackets for the rock shaft I'I, these being V.disposed adjacent the respective sides of the press frame. To each of thesebrackets is attached'as by meansof the bolt 24, a bearing member 25 in which the rock shaft has a bearing at a point betweenits middle'portion and its extremities,` As shown in Fig.. l, therock' shaft projects to the right and left beyond the bearing members, and the swinging arms I8 are carried bythe rock shaft outwardly from theV bearing members. Each, of the arms I9, which can be conveniently made vof tubular metal stock, is attached by means :ofa screw 28 to a collar 21 that is rigidly fastened as by screws 2B to the rock shaft, the arrangement being such that', as

therock shaft is'turned in its bearings, the arm I9 is swung forwardly or rearwardly as the case may be.v The arm I9 is rigid with the rock shaft transversely of the shaft but'isfree to `swing lengthwise of the shaft, the connection of the arm to the collar 21 by means of the screw 2t being a pivotal connection, Screw 2B passes throughan aperture inthe arm, and Visset'np so that the arm can swing as above mentioned, and follow ythe angle ofthe guide. bar 29. A set screw 26e in the collar 2'! fixes the screw 25 in the proper position and prevents itxfrom Vworking loose after adjustment. TheV guide bar 20 is swiveled at one end to the press frame, and for this purposev the guide.' bar proper has`welded' thereto at the end adjacent the press frame a vertical swiveling pin Ztl-that is engaged ina swiveling socket 3D formed inabracket 3l' that is attached in a suitable manner, as by bolts 32,'

to the front face of the press frame. In this manner there is provided an upright pivotmerm` ber for the guide bar enabling the bar to beswung"Y to any of a numberof different-'angular positions in a horizontal plane. After the bar has been adjusted to the desired position it can be fixed in'this position as by meansrof set screws 33 Vassociated with the swiveling socket that can be screwed inwardly to clamp 'the swivel pin against movement.

f When the Vguide'bars 2B are 'in the position shoWnin full lines in Fig. `3, the armsl I9 will swing in vertical planes transverse to the rockshaft, but when thel guide bars are swung angularl, asindicated for-example 'by thedotted lines at the right of Fig. 3,the `arms I9, in moving fore wardlyv and rearwardly,4 will swing' in planesV which are tipped-.or tiltedfwith respect tothe vertical. f f

Itisrnot desirable that the arm I 9, be swung to an excessive angle longitudinally of the, rock shaft, andfor limiting this adjustment suitable portion of the swinging arm at a point somewhat means are provided in association with the ends of the rock shaft. In the present case each end of the rock shaft has fastened thereto, by means such as a fastening screw 34, a forwardly projecting stop plate in the forward end of which is carried an adjustable stop screw 3S provided with a lock nut 31. This screw 3B has an extremity projecting through the` stop plate 35 towardA the side of the corresponding swinging arm I9 and adapted to be contacted by the side below the yupper pivotal connection of the arm with its mounting collar. This pivotal connec vtion between the arm and the mounting collar missible angular shift/of the arm lengthwise of' the rock shaft can be adjusted as desired.

For the purpose of permitting some adjustment of the rock shaft toward and away from the opposing face of the press frame, the brackets .'3 may have slots 38 in their lower or horizontal legs 39 in which the bolts 24 for supporting the rock shaft bearings are adjustable. This is of advantage in permitting adjustment in the cam connection provided between the rock shaft and the upper end portion of theV connecting rod head, which connection is described at a'later point. For facilitating effective clamping of the rock shaft bearings in place, washers 46 underlying the nuts 2da on the bolts may have roughened or serrated surfaces vengaging the bracket parts 39.

In order to lirnt'endwise movement of the rock shaft in its bearings, thrust collars 4I and 42 may be rigidly fastened on the shaft adjacent the innersides of the bearing members 25. purpose of limiting the forward swing of the depending arms I9, suitable means are provided. In the present instance this meansV comprises a stop bar 4'3 which is tangentially arranged with respect to the thrust collar 42 and is welded to the thrust collar. The` disposition of the stop bar relatively to the thrustcollar is as shown in Fig. 5, and the arrangement is such that, Vwhen the arm I9 is swung outwardly'to the position shown in Fig. 2, the upper end of Vthe Vstop bar engages the forward extremity of the adjacent bracket I3 for the purpose of arresting movement of the arm. While this is the preferred arrangement, other means may be used for arresting .the forwardly swinging arm I9 at the desired point.

Referring now to the cam mechanism between the connecting rod head and the rock shaft, it will be noted thatl in the form illustrated the upper end ofthe connecting rod head I6 is provided adjacent its fro-nt face with a bracket 64 carry-- ing at its forward end a roller d5 that is adapted to engage a tongue-shaped cam member fixed' to the rock shaft at the central portionI of the rock shaft. The member it has an Aupper portion 4'! in the form of Va split ring or band embracing the rook shaft and adapted to bev clamped fixedly in the desired angular position thereon by a clamping bolt d8. Y Projecting downwardly from the ring portion or band portion rof this member is the tongue portion or depending cam arm of the memben'which tongue portion is curved forwardly and downwardly with reference to the drive shaft of the press, as shown fory For the' asse-,o23

example in Fig. 2. The'rcller 45 will notl make contact with the member 46 when the hand of J the operator is kept out of the path of the" descending punch, but if the hand is in the position shown in Fig. 4, for example, where it is under and in line with the punch, the member 46 will be engaged by the roller 45, with the'result that the arm I9 will be kicked'outwardly to will be actuated to pull the hand out of danger. I The spring 23, previously mentioned, is in this..

particular case interposed between a part on the rock shaft anda portion of the left-hand bracket I8 (Fig. 3). v spring having an intermediate coil branching ends 23h. upright vpart of the adjacent bracket I8 by means of a screw 4'9. The other extremity of the spring is secured by a screw 5B to a radial projection 5I on a collar 52 rigidly fixed to the rock shafft at one side of said bracket. When the arm I 9 is moved to the position of Fig. 4, the coil of the spring 23 is tightened, and the spring further energized. Normally, however, the spring holds the stop bar 43 against its cooperating bracket (Fig. 2).

The guide bars 2!! may be made conveniently of tubular metal stock and at their forward end portions they are preferably curved upwardly on a gentle curve, as shown.

23a and The wristlet 2I is provided with a loop Ia ex for kicking out the swinging side arm involves'A a contacter member 53 which is rigidly attachedk to the press gate 54. The contactor 53 is adapted to kick out the side arm by making contact with the knee portion 55 of a rod 56 that is adjustable longitudinally in a clamp 51 rigid with,l a member 58 that is rigidly clamped to a rock shaftV 59 corresponding to the rock shaft Il' previously described. The clamp 51 has a bore in which the rod 56 is received, and screws 60 are adapted.

to clamp the rod in adjusted position in theibore.A By this arrangement the device can be setmso;y that the xed camming contactor on the press gate will, by engaging the camming rod ordepending cam arm 56, actuate the swinging side arms in the proper manner, as previously -described. The side arms may have the same arrangement with respect to rock shaft 59 as hereinbefore described.

In the modied form shown in Fig. 7, which is particularly adapted for use on a straight medium-stroke press, the contactor 6I on the press gate is adapted to make contact with a depending cam arm member 62 clamped to the 'rock' shaft 63. In this case the member carried-'by the rock shaft is a non-adjustablemember so'f'ar as the camming action is concerned, but the vcon-- tactor 6I is adjustable in a vertical direction on. the press gate. For this purpose the press-gate One end is secured to th.

This spring is shown as a wire` may Ybe 'equippedwith an outstanding plate 64' spaced from the gate'and having a vertical slot 65. 'I'he contacter 6I is rigid vwith a plate 66 positioned against the forward face of the plate 64 and vertically adjustable by means of clamping bolts B'I passing through the slot 65. b y

It will be evident that the described structure includes a rock shaft applied to the forward f ace of the press in a location substantially above the location of the work and having attached to the rockshaft depending swinging side arms having at their lower ends flexible connections tothe arms of the operator for pulling the hands out of thedanger zone, there being between the rock shaft and the upwardly and downwardly moving working element of the press a cam mechanism acting as a kick-out device which, if the operators hands are in the danger zone as the press punch approaches them, klcksthe side arms vfor wardly in a positive and rapid manner so as to pull the hands from the danger zone with all of the force required for the purpose. The spring will tend to pull the side arms .forwardly and normally will maintain the cam member on the rock shaft clear of the cooperating camming member, but will not exert too much Arestraint upon the operators arms. The kick-out action,

it will be noted, takes place against a portion of the cam mechanism which is comparatively close to the rock shaft in the forms of Figs. 1,

`The device is of relatively simple and inexpe'nsive structure, and yet is susceptible of adjustment in order to meet-different conditions of use, and when the device is in use it does not inter-` fere with the operators access to thefwork, nor

does it obscure the operators view*v of the'work,` nor is it likely to cause injury to the operatorsl hands by striking or bruising them. A very conf siderable advantage also arises from the4 fact that the swinging side arms are clear'and free.

of the space between the plunger andthe die-at all times, and are maintained by the guide barsi in their proper zones of operation, and are prevented from swinging inward from their pre-.i1 scribed positions, as adjusted, and that the sideV arms, when the gate is descending and the operator's hands are in the danger zone, and only at that time, `pull with suiiicient (and ample) force on the hands to move them to safety', theaction under such circumstances beinga posi" tive oneas well asarapid one. Y s

Where reference is made to the operators hand being in the path of the ram, theA term` "ram is used in a broad sense so as to apply tof a ram structure carrying a punch or like element likely to cause injury to the operators ing from the principles ofthe invention or the scope of the claims. I

-What I claim is:

1. In a machine of the type described having' a ram or gate vertically movable in a frame and having a bed below the ram adapted to hold a workpiece to be operated upon, a pair of arms'4 7 having upper ends swingingiy mounted-at the' front of the frame at an elevation ab'ovethe workand having lower ends-'flexibly connected to wristlets, said arms being adapted to swing forwardly and rearwardly at the sides of the ram, means forfguiding the'lower end portions of saidarms in a forward and rearward direction, and means operatively connecting a moving part of the press with theiupper ends of said arms -to swing Vthe arms forwardly, said vmeans being operable only when the operators hand is in the danger zone underthe ram and when the ram has descended to a predetermined point. Y

2;.'InY a machine of the type described having al ram or gate verticallymovable in a frame and having a bed below the ram 'adapted to hold a workpiece to be operated upon, a pair'of arms having' upper endsswingingly mounted at the front of the' frame at an `elevation above the Werl: andhaving lower ends exibly connected to wristlets, said arms beingadapted to swing forwardly and rearwardly at the sides of the ram, means for guiding the lower end portionsV of said arms in a forward and rearward direction, and means operatively connecting a moving part of the press with the upper ends of said arms tov swing the arms forwardly, said means being operable only when the operators hand is in the danger zone under the ram and when the ram has descended to a predetermined point, said means including a" camming ymechanism having operative engagement of parts thereof by which the arms are kicked forwardly.

3. In a device such as described, the combination with a press having a bed, an upwardly movable ram, and a guide Yframe for thev ram, of c a horizontal rock shaft mounted from the frame at the front of the press, side arms having upper ends transversely rigid with the rock shaft and'having lower ends flexibly connected to the operators hands, a cam device for operatively connecting said rock shaft with an upwardly and downwardly Vmovable part of the press at the front of the press, said cam device being operable'to kick said arms forwardly when the ram has descended toa certainv point and when the operators hand is in the path of the ram, and a spring acting on said arms and tending toV hold the arms in a position in which the operators hands will Abe out of the path of the 4. In a device such as described, Vthe combination with` a press having a bed, an upwardly movable ram, and a guide frame'for the ram, of a horizontal rock shaftvmounted from the frame atthe'front of the press, side arms having upper endstranjsversely rigid with the rock shaft and having lower ends flexibly connected to the.op` erators hands, a cam device for operatively connecting said rock shaft with an upwardly and downwardly movable partof the press at the front of the press, saidcamzdevice being operable to kick said arms forwardly when the ram has descended to a certain point and when'the operatorshand is in the path of ther ram, a spring.

acting on said arms and tending to hold the arms .in a position in which thev operators hands will be: out of the. path of the ram, and forwardly, projecting guide bars at the sides of the ram which guide the lower ends of said arms asrsaid ends move in a forward and Vrearward direction.

5. In a device such as described, the combination with a press having a bed, an upwardly movable ram, and a guide frame vfor the ram,

of ahorizontal rock shaft mountedfr'omi the frame 'at the front of the press, side arms having upper ends in pivoted relation tothe rock shaft to swing lengthwise of the shaft and having lower ends exibly connected to the operators hands, a cam device for operatively connecting said rock shaft with an upwardly and downwardly movable part'of the press at the front of the press, said cam device being operable to kick said arms forwardly when the ram has descended to a certain point and when the operators hand is in the path of the ram, a spring acting on said arms and tending to hold the arms. ina position inY which the operatorshands will be out of the path of the ram, and Vforwardly projecting guide bars at the sides of the ram which guide the lower ends of said arms as saidends. move in a forward and rearward direction, said guide bars being mounted on the press 4soas to` be swingable in a substantially horizontal direction.

6. Ina machine of the type described havingv a vertically moving ram or gate above a bed, on which work is placed for tool operation, the ram or 'gate being guided in the machine frame, a horizontal rock shaft mounted adjacent the forward face of the frame,l depending swinging side arms fastened to said rock shaft and having their lower ends exibly connected to the hands of the operator for pulling the hands out vof, the path of the ram, guide bars projecting forwardly from the face of the machine frame contacting with the lower parts of said side arms and interposed between the side arms, and cam mechanism between the rock shaft and a movingpart of the machine for kicking the side arms, inA an outward or forward direction when the operators hand is in the ram path and the ram reaches a certain point in its movement.

7. A machine as defined in claim 6, in which the side arms are fastened to the rock shaft so as to be tiltable 'to move in planes .inclined to the vertical and in which the guide bars are swivevled adjacent the machine frame and are adjustable horizontally.

8. A machine as defined in claim 6, in whichv the lower ends of the side arms are `adjustable outwardly and laterally with respect to each other, and in which the vrock shaft is provided with adjustable stop means at the ends of ther rock shaft whereby the adjusting movement .of the side arms is limited.

9. Ina machine of the type described havinga vertically moving ram or gate above a bed` on which work is placed for tool operation, the ram or gate being guided in the machine frame, a horizontal rock shaft mountedv adjacent the forward face ofthe frame and having bearingv members adjustable toward and away from the frame, said bearing members being carried. byl bracketsr applied to the face of the frame, depending `swinging sidev arms fastened to said rock shaft `and having their lower ends flexibly connected to the hands of the operator for pulling the hands out of the path of the ram, a

spring having a middle loop and branched end portions, one of the end portions being connected to one of said, brackets and the other end portion being connected to a part rigid with said rock shaft, said spring tending to hold said side arms normally in positions in which the operators hands are out of the path of the ram,`

a stop member in the form of a bar iiXedly ap- Y plied to a member rigid with said rockv shaft,

said bar being .adapted to engage `one .of said brackets so as to limit the forward and outward swing of said arms, and mechanism between the rock shaft and a moving part of the machine for kicking the side arms in an outward or forward direction when the operators hand and the ram are in certain positions.

10. A machine such as described, comprising forwardly and rearwardly swingable side arms at the sides of the machine adapted to pull the operators hands out of the danger zone, said arms being movable in verticalplanes at the sides of the machine and being adjustable so that they can be placed in inclined planes, and adjustable forwardly projecting guide bars contacting the lower portions of said arms.

11. In a machine of the type described having a vertically moving ram or gate above a bed on which work is placed for tool operation, the ram or gate being guided in the machine frame, a horizontal rock shaft mounted adjacent the forward face of the frame, depending swinging side arms fastened to said rock shaft and having their lower ends flexibly connected to the hands of the operator for pulling the hands out of the path of the ram, stop means in connection with the rock shaft and the rock shaft mounting for arresting the side arms when they reach a predetermined forward position, a spring normally holding the side arms in said predetermined forward position, guide bars projecting forwardly from the face of the machine frame contacting with the lower parts of said side arms for guiding the same and interposed between said side arms, and mechanism interposed between the rock shaft and a moving part of the machine for kicking the side arms in an outward or forward direction when the operators hand is in the ram path and the ram reaches a certain point in its movements.

12. In a machine of the type described, having an upstanding frame comprising side members and a vertically moving ram or gate between said side members and above a bed on which work is placed for tool operation, a horizontal rock shaft at the front of the machine above the bed, bearing members on said frame members in which said shaft is mounted for oscillating movement adjacent the forward face of the frame, side arms fastened to said rock shaft beyond and outwardly of said bearings at the sides of the machine and depending from said shaft and having their lower ends iiexibly connected to the hands of the operator for pulling the hands out of the path of the ram, and mechanism between the rock shaft and a moving part of the machine comprising a downwardly and inwardly curved tongue or cam arm fixed on the shaft intermediate of the ends of said shaft and between the side members of said frame coacting with a roller on said moving part to kick the side arms in an outward or forward direction with respect to said bed when the v'operators hand is in the danger zone under the ram and the ram reaches a predetermined position.

13. In a machine of the type described, having a ram or gate vertically movable in a frame and having a bed below the ram adapted to hold a workpiece to be operated upon, a rock shaft disposed horizontally adjacent the forward face of the frame and arranged to oscillate in bearings on the frame, a side arm fastened to said shaft at one side of the machine and depending from said shaft and having its lower end flexibly connected to the hand of the operator for pulling the hand out of the path of the ram, said arm being fastened to said shaft so that the arm in moving generally forwardly and rearwardly can have a certain amount of lateral swing, means engageable by the inner side of the arm for guiding the lower end of said arm in a forward and rearward direction, and mechanism between the rock shaft and a moving part of the machine for kicking said arm in a forward direction when the operators hand is in the danger zone under the ram and the ram reaches a predetermined position.

14. A machine as defined in claim 13, in which the rock shaft has associated therewith means for limiting the lateral swing of the arm.

EDWIN R. FERRER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED` STATES PATENTS

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