US2707407A - Safety device for presses - Google Patents

Description

May, 1955 w. GoNsLER 2,707,407

SAFETY DEVICE FOR PRESSES Filed Oct. 2, 1951 2 Sheets-Sheet il May 3, 1955 w. GoNsLl-:R 2,707,407

SAFETY DEVICE FOR PRESSES Filed oct. 2, 1951 2 sheets-sheet 2 '75 5 BY mi. EMM Egg/E.

SAFETY DEVICE FR PRESSES Wiliiam Gonsler, Flint, Mich. Appiication Uctober 2, 1951, Serial No. 249,352 5 Ciaiins. (6l. 'i4-612) The present invention relates` to a safety device for punch presses and the like and more `jgsarticularly to a safety device of the type in which the power stroke of the press is actuated by the safety device after a downward and sidewise sweeping of the area above and adjacent to the work piece.

Heretofore various types of safety devices andV guards for` power` presses have been proposed, most of which embodied the inventive concept of providing means adapted` to prevent the operators hands from being placed in the space between the upper and lower die during the power stroke of theA press. Devices of this type have been hitherto actuated separately from the operation of the power press ram and usually the sweeping operation is completed before the stroke of the powerpress is initiated. To my knowledge, there has been no 'i suggestion of providing a safety device combining the features of sweeping the area above and adjacent to the work piece at least partially prior to the stamping operation with means for actuating the power stroke of the press responsive tothe operation of the downward `f' sweeping motion of the safety device. suggestion has been made of a safety device which is adapted to deenergize a power press upon contacting a foreign object during the sweeping operation.

it is therefore one of the objects of provide a safety device which combines means for sweeping the area above andadjacent to a work piece, and energizing the stroke of the ram of a power press.

A further object of this invention is to provide a device of the above type wherein the ram of the power press is deenergized when a foreign object is contacted in the area above or adjacent to the work piece.

Another object of this invention is to provide a safety device of simple construction and operation which may be readily applied to a power press and easily adjusted horizontally, vertically and angularly to sweep the desired area.

Further objects and advantageous features of the invention will be specically mentioned or will become ap- Furthermore, no

parent upon considering the present disclosure in its` t" entirety.

In the drawings:

Figure 1 is an elevational view showing a device mounted in place on a punch press and embodying the features of this invention.

Figure 2 is a plan view of the structure illustrated in Figure l;

Figure 3 is a view, partly in elevation and partly in section, of the device illustrated in Figure l taken along the line 33 thereof and looking in the direction of the arrows;

Figure 4 is a view partly in elevation and partly in section of the apparatus illustrated in Figure 1 taken along the line 4-4 thereof and looking in the direction of the arrows;

Figure 5 is a sectional view of the device illustrated in this invention to 2,707,407 Patented May 3, 1955 Figure l taken along the line 5 -5' thereof and'` looking inthe direction of the arrows;

Figure 6 isa sectionalview of the device. shown in Figf ure 1 taken along the line 6*-6 thereof and looking in theV direction of the arrows.`

Figure 7 is a View similar to Figure l, however, taken sectionally in order to more clearly indicate, the interconnection between the plunger andthe panel.

Referring in greater detail to the drawings,` there. is shown in Figures 1 and 2 a power press generally designated Ill' having uprights 11` and 1:2, a base 13-supporting the uprights, a vertically reciprocating ram 14 and a work piece 15 positioned beneathvthe ram and in verticalalignment therewith. The press 10 is of conventional design and the ram 14 which is adapted to reciprocate in guide.-

ways 11av andy 12a carries a, standard punch, while the work piece is mounted on a conventional die.

The safety device embodying the features of. thisfinvention `and generally` designated 16 is supported, on uprights 11 and' 12 by means of a. pair of outwardly extending vertically spaced. securing membershaving horizontal portions 23 and- 24 which are integrally attached to the uprights by screws 123 and 124.,

A pair of end plates 18 and,19,.adaptedfor engagement with horizontal` supports 23- and. 24,: are` positioned at the outer extremities ofsupports` 23= and 24 by theengagement, of positioning slots 21 and' 22 respectively therewith. As may be seenplateszlland 194 are mounted vertically between members 23 and 24, andtheapertures 18a yand, 19aenable the plateslS and- 19` to` be positioned in any of the plurality of slots Zittend-22ers desired. Device 16 is mounted between end plates 181 and 19 and directly supported by horizontally disposed rodi 17y which is positionably secured in` apertures 2d and 20 ofoutwardly extending endvplates 1t; and 19 respectively. lt will benoted that rod 17,:is adapted for positioning in any one of, the sets of apertures. 2d and 2li( carried by end plates 1S-andfi9 andis secured against disengagement by pivotal armst117. and 117 whichare pivoted-for rotation about pivots,118.and 119 respectively. The outer end extremities ,of armsrl-gil", andai-17" are provided, with semicylindrical shaped concavities adapted to engage the periphery of, rod 17 and maintain it in position in the selected apertures` 20 and 2d. Adjustment slots 20` and 20 are disposed onan arc generallyparallel to` the eX- terior arc. of end plates-.18' and 19 thereby providing a plurality off positions: which vary the positionsy that may be-assumedbyV devicel bothV horizontally and-vertically;

Rod 17 is engaged` by outwardly extending guide 27 ofl device land rigidly secured theretoV by suitable means suchras. clarnpfli and screws 129.

Vertical guide. member 25, comprising a pair of vertically disposed uprights 28y and-i 29 is connected to rod 1:7 by. meansof vertically extending plate 26 which is attached in turnto outwardlyl projecting horizontally disposed guide 2'7V by dovetailed connection 70. Suitable bolts 125 provide the adjustable attachment of plate 26 and uprights 28. audv29. Horizontally spaced uprights 28 and.29have their upper portions grooved" at 30` and 31 respectively to-` enable plate` 26 to be moved relative thereto to adjust the verticalpositioning.l tion of` uprights 28- and 29 designated 28a and 29a respectively areprovidedwith grooves 33 and 34' in the front. face of thek outwardly curving portion. Thus it willf be observed that rod 17 supports device 16 having the frame consisting of guide 27," plate guide member 25.

For the purpose the safety device a vertically reciprocative ram 36responsive to Huid presofA providing automatic actuation` of sure which may be, admitted to cylinder 3S through aperture jand vented therefrom throughconduit 37 and conduit 39'in a conventional manner. Cylinder 35 is Theflower por- 26 and vertical 16, cylinder 35 is providedand housesl mounted on plate 26 which is formed of two parallel platelike members 126 and 1266: which are separated by spacers and 41 and secured by suitable means such as bolts 32. The lower extremity of ram 36 is provided with a pair of horizontally extending arms A42 and 43 which are rigidly connected thereto by connector 44. Downwardly depending from arms 42 and 43 and movable therewith are panel supporting arms 45 and 46 having upper guiding portions 45a and 46a respectively. The lower portion of arms 45 and 46 is divided into two parts at the approximate median points by hinges 47 and 48. Horizontally disposed sweeping panel 49 is pivotally connected to arm 46 at a point closely adjacent to its upper and left hand end extremity by pivot 50. A horizontal elongated slot 51 is provided in panel 49 which is parallel to the upper extremity thereof but spaced downwardly therefrom and extending from a point adjacent to pivot 50 longitudinally to a point near the right hand end extremity as viewed in Figure l. Slot 51 is adapted to engage pivot 52 carried by arm 45.

As may best be seen in Figure 3, arm 46 is provided with rearwardly projecting pins 53 adapted to engage a guideway 54 provided in the forward face of upright 29 and it will be understood that arm 45 is similarly guided by a guideway in upright 28. The lower extremity of guideway 54 is adapted to mesh with guideway 34 provided in the lower extremity 29a and it will be apparent that as plunger 36 moves downwardly that pins 53 will follow guideway 54 and thereafter engage guideway 34 causing panel 49 to be swept in a sidewise direction, to the left as viewed in Figure l, to assume the position indicated by the dotted lines. During the sidewise motion pivot 52 freely rides in slot 51 thereby maintaining the level of panel 49 as it sweeps through the latter portion of its motion.

As may best be seen in Figure 4, panel 49 is comprised of an upper portion 55 and a lower bifurcated portion 56. Upper portion 55 is secured to arms 45 and 46, which are likewise bifurcated, by means of the pivots 50 and 52. Lower bifurcated portion 56 is provided with pins 57 adapted to support downwardly depending iinger portion 58 in slot 59 of nger portion 58. Finger portion 58 may be fabricated from a variety of materials but it is preferred that the material selected be one which will not cause injury to the hands of an operator opon contacting the same and for this purpose resilient materials have been found to be rnost suitable such, for example, as rubber, rubbery plastics, etc. The resilient material forming the lower extremity 60 of lower panel portion 58 is preferably corrugated or provided with a multiplicity of downwardly extending iingers in order to insure that any foreign object contacted by the motion of panel 49 will not be passed over but will cause an upward motion thereof in response to the contact; or

the object will be moved aside by the motion of panel 49. A conventional electrical switch 61 is positioned in the bight portion of the bifurcated member 56 and is adapted to be actuated by the upward travel of member 58 when surface 62 contacts and depresses surface 63.

ln order to render the safety device 16 of this invention adaptable to a wide variety of power presses, means are provided for positioning the device vertically, horizontally and angularly such that the travel of arms 45 and 46 will cause the sweeping of the area in which the greatest likelihood exists of the presence of foreign objects such as the operators hands, etc. As referred to hereinbefore, the outward extension of safety device 16 may be adjusted by the selection of the desired slots 21 and 22 which are positioned over supports 23 and 24. Additionally, a combination of horizontal and vertical adjustment of the entire device 16 may be achieved by varying the position of rod 17 in the apertures 20 and 20 of end plates 18 and 19. Furthermore, and as may be seen in Figure 5, means are provided for angularly tilting device 16. This means comprises an outwardly eX- tending arm 64, having therein an aperture to receive rod 17, the aperture and rod having a square cross section at this point thereby preventing rotation of rod 17 relative to arm 64. The inner extremity 65 of Aarm 64 is in the form of a portion of an arc and the peripheral surface thereof is provided with a plurality of teeth 66. Teeth 66 are adapted to engage a single tooth 67 carried by an arm 68 pivotally secured to end plate 18 by pivot 69 and interconnected to arm 64 by spring 70. It will be apparent that an angular shifting of rod 17 may be accomplished by raising arm 68, moving arm 64 to the desired position and thereafter inserting tooth 67 in mesh with teeth 66 to maintain the new position. Spring 7i) serves the purpose of preventing the disengagement of and maintaining arms 64 and 68 in any xed position Set by the operator. lt will be understood that arms 64 and 68 may be so adjusted as to offset the angular displacement of the vertical axis of device 16 which occurs upon shifting the position of rod 17 into any of the apertures 20 and 20.

For finer adjustments it may become necessary to position device 16, either horizontally or vertically, an amount less than that which may be obtained by the adjustment of bar 17 or end plates 18 and 19 as previously described. For the purpose of providing iiner horizontal adjustment of device 16, there is provided a downwardly depending dovetail projection 70 adapted to engage conjugate slot 71 carried by outwardly projecting guide 27. Surmounted on guide 27 is gusset-shaped portion 127 which is provided for the purpose of reinforcing and strengthening the dovetailed connection between guide 27 and adjustable plate 26. Horizontal displace ment of device 16 along dovetail slot 71 may extend for the complete length of guide 27 and the desired position maintained by tightening set screw 72. Fine vertical adjustment of plate 26 and frame 25 may oe secured relative to guide 27 when desired by means of outwardly projecting vertically disposed dovetailed member 38 adapted to engage the dovetailed slot carried by the rearward extremity of guide 27. The adjustment means is comprised of a bifurcated arm member 223 having a handle portion 229 and lower end portions 13? and 131 carrying pins 132 and 133 respectively. Arm 228 is pivoted for rotation about pivot 134 carried by gusset-shaped portion 127, and the front face of plate 26 is provided with a plurality of apertures 135 and 136 adapted to accommodate the positioning therein of pins 132 and 133. Positioning is secured by raising or lowering piate Z6 and inserting pins 132 and 133 in suitable slots to maintain the position.

Mounted on the left front face of plate 26 is upright member 73 having attached to its lower extremity an otion electrical switch 74 adapted to be engagedV by outwardly projecting runner 75, which is carried by arm 46, upon the downward travel of arm 46 in response to the motion of piston 36. Member 73 is adjustably positioned on plate 26 by screws 76 operative in a vertically extending slot 77 positioned in the face of member 73. it will be understood that the relative time of operation of electrical switch 74 may be controlled by varying the position of member 73 in relation to plate 26. Switch 74 is a conventional electrical switch and is adapted to actuate rarn 14 of the power press when depressed, and it will be apparent that the relative positions of upright 73 and runner' '75 will determine the stage at which the motion of ram 14 will be commenced relative to the sweeping action of safety device. In most instances, it will be desirable to so adjust member 73 that ram 14 is not energized until the major portion of sweeping action of the safety device 16 is accomplished. On the other hand, in operations requiring a high production rate, it may be desirable to energize ram 14 prior to the complete sweeping operation of safety device 16. For these types of operations, an added safety feature is provided in the form of the master control switch 61 which, as previously described, will deenergize ram 14 if a foreign body is contacted by the finger-like portion 60 of panel 49 during its traverse of the area adjacent to the work piece.

A typical cycle of operation of the safety device cf this invention and the press itself is initiated by the manual admission of fiuid under pressure to cylinder 35. As the fluid is admitted to cylinder 35, piston rod 36 moves downwardly, carrying with it arms 45, 46 and sweeping panel 49. Electrical switch 61 which as above explained, is carried by the bifurcatcd portion 56 of panel 49 is normally closed, and switch 74 which is Supported on stationary upright 73, is normally open, and both switch 61 and switch 74 are in series in the electrical circuit which controls the actuation of the ram 14 of the press. As piston rod 36 descends, arm 46 having runner 75 attached thereto, engages switch 74 to close the same and complete the circuit to thereby actuate a conventional power means (not shown) which causese the downward motion of ram 14 of the press. lf, during the downward motion the finger-like portion 60 of panel 49 engages any foreign object, the portion 60 will be raised vertically to depress switch 61, thereby opening the electrical circuit supplying power to ram 14 and thus immediately stopping the downward travel thereof. After ram 14 has fully extended downwardly and performed its stamping operation, piston 36 and ram 14 are returned to their initial positions. As will be appreciated by those skilled in the art, the return of piston 36 to its initial position may be automatically controlled by conventional means responsive to the upward movement of the ram or may be manually controlled, as desired.

Inasmuch as switch 61 is the master switch and must be closed before the ram can be energized, it is clearly apparent that a high degree of safety is inherent in the use of the device of this invention.

While only one modification has been illustrated and described, it will be apparent that various minor changes, omissions, and additions may be made without departing from the spirit and scope of the invention. It is to be understood that the safety device of this invention may be attached to presses having horizontally reciproeating rams and that the directions of motions set forth in the specification are illustrative only.

What is claimed is:

1. A safety device for a power press comprising a frame supported by a horizontally disposed rod which is adjustably mounted on outwardly extending end plates supported by uprights of the frame of said power press, a forwardly extending guide attached to said rod and a vertically disposed plate adjustably secured thereto, said plate carrying a pair of spaced uprights, cylinder means carried by said plate and housing a vertically reciprocative plunger, a pair of horizontally extending arms carried by said plunger and arms vertically depending from said horizontally extending arms, said latter arms adapted to move responsive to the motion of said plunger and along guideways carried by said uprights, a horizontally disposed guard panel pivotally attached to the lower extremities of said arms, downward travel of said plunger effecting downward motion of said panel and thereafter a sidewise sweeping motion which is a combination of horizontal and Vertical motion.

2. A safety device as claimed in claim I Wherein said panel member includes an upper panel portion and a lower panel portion movable relative to said upper portion.

3. In a power press having a reciprocating ram the improvement of a safety device comprising a support for said device carried by said press, a frame mounted on said support, said frame having a horizontal guide member, a plate member and a vertical guide member, cylinder means carried by said plate housing; piston means responsive to uid pressures, said piston means carrying a horizontally disposed panel member' for sweeping the area above and adjacent to a work piece, means incorporated in said horizontal guide member for adjusting the horizontal position of said device, means incorporated in said plate member for adjusting the vertical position of said device, and means incorporated in said support for angularly adjusting the position of said device relative to vertical.

4. In a power press having a vertically reciprocating ram, a safety device comprising a support and a frame carried by said support, guard supporting and actuating means mounted on said frame, said means comprising a vertically movable piston having a pair of downwardly disposed spaced arms attached thereto, said arms being pivoted intermediate their ends, a horizontally disposed guard pivotally attached to said arms, the downward motion of said piston effecting first a downward movement of said arms and said guard and thereafter a sidewise sweeping motion of said guard.

5. A safety device as claimed in claim 4 wherein said device is provided with angular adjustment means incorporated in said support for adjusting the angle of said device from its normal vertcal position, horizontal and vertical adjustment means incorporated in said frame for adjusting the said device horizontally and vertically relative to said press.

References Cited in the file of this patent UNITED STATES PATENTS 1,430,918 Miller Oct. 3, 1922 1,439,818 Hordun Dec. 26, 1922 2,030,976 Fairfield et al. Feb. 18, 1936 2,383,221 Skoog Aug. 21, 1945 2,429,261 Ewaldson lOct. 2l, 1947 2,443,726 Dickerman June 22, 1948 FOREIGN PATENTS 220,453 Great Britain Aug. 21, 1924 628,294 Great Britain Aug. 25, 1949 695,949 Germany Sept. 6, 1940

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