US2240915A - Safety guard - Google Patents

Description

y 6, 1941- I w. H. SEARJEANT 2,240,915

' SAFETY GUARD I Filed Nov. 16, 1938 2 Sheets-Sheet l 25%?23 FIGS H66 l INVENTOR y 1941- 'w. H. SEARJEANT 2;240,915

SAFETY GUARD Filed Nov. 16, 1932; 2 Sheets-Sheet 2 11v VENTOR Wu Fan 7 SEAFJEA/YT a A T TOR -BYI Patented May 6, 1941 M? OFFICE 15 SAFETY GUARD Wilfrid H. Searjeant, RochesteigN, Y," assignor to Taylor-Shantzlna, R.ochester,N. Y.', a corporationof New York Application November 16, 1938, Serial No. 240,773

' 6 Claims. (-01. 14- 615) This invention relates to safety guards for presses, shears etc. and has for its principal object to provide a safety guard which will efficiently, guard both small and large danger zones on machines having operating memberswith uniform or variable long movements, such as hydraulic presses, compressed air operated presses, toggle presses, percussion presses, shears etc.

A further object of this invention is to provide a safety guard which may be made to operate during any part of the movement of an operating member.

- Another object of this invention is to provide a safety guard-that will force the operators hands or arms out of the danger zone in advance of the closing movement of the operating member and then form an efficient protective barrier during the closing movement.

All these and other objects and attendant advantages of this invention will become more clearly apparent from the detailed description thereofwhich follows, reference being had to the accompanying drawings in which Figure 1' is a frontv elevation of a hydraulic press equipped with the safety guard.

Figure 2 is a vertical section taken on the line 2-2 in Figure 1.

Figure 3 is a horizontal section taken on the line 33 in Figure 1.

V Figure 4 is a horizontal section taken on the line 4-4 in Figure 1.

Figure 5 is an enlarged front elevation of the safety guard and its actuating member.

Figure 6 is a horizontal section taken on the line B6 in Figure 5.

The safety guard, forming the subject matter of my present invention, is especially adapted for use on presses, shears etc. in which the operating member has a long and not too fast movement. Any form of press may have the guard attached thereto and for illustrative purposes I have shown and described it in connection with a hydraulic press in which a hydraulic ram I operates a movable bed 2 toward a stationary'head 3 to subject the material to be operated upon to the pressure of the ram thru suitable forming dies 4, 4. The press has the base 5 and on this base are supported the uprights 6, 6 which adjustably support the head 3 by means of the nuts 1, l and guide the bed 2 in its movement toward and away from the head. To prevent injury to the operator of the press he must remove his hands or have them forceably removed from between the dies on their closing movement or keep his hands fromentering between the dies during the closing movement thereof. 3

These protective functions are efiicientlyperformed by my safety guard which comprises a number of pairs of levers 8, 8 which are pivoted together at the middle at 9, 9 and hinged to one another at the ends at l0, ill to form an expansible and contractible gate-like structure as illustrated in Figure 5. The bottom end of one of the pair of levers 8 at the right hand end of the gate is pivotally mounted on the pivot stud ll carried by the lower end of the supporting memher. or upright I2 and the upper end of the other of the pair of levers 8 at the right hand end of the gate is pivotally connected to the arm I3 which in turn is mountedto swing on the pivot stud I4 carried by the bracket 15. The latter is mounted on the side of the supporting member l2 so as to form a part thereof.

To operate the levers so as to have'them extend in the manner illustrated in dotted lines in Figure 5, an extension arm I6 is attached .to' the lever end pivoted on the pivot stud H and the movement of this extension causes all of the levers to swing on their center pivots and force the. hinged ends apart or bring them together to expand or contract the gate formed by them- The upper end of one and the lower end of the other of the pair of levers 8 at the free end of the gate have the guide blocks H and I8 pivoted thereon. Each of these blocks is grooved on the inside at [9 with a cover plate 28 held over the groove. The guard arm 2| extends thru these grooves and is normally clamped into the block I 8 by its cover plate 20 to fixedly support it thereon while the guide block I! is allowed to freely slide up and down on the guard arm. In this way the movement of the guide block ll on the free moving end of the gate and the swinging arm 13 on the stationary end thereof permits the levers of the gate to move in unison. A stop pin 22, which projects from the supporting member, keeps the swinging arm I 3 from swinging too far so that the return movement of the gate from its extended position will not be delayed or made difficult by the alignment of the pivotal connection between the arm l3 and the lever 8 with the center of rotation of this arm and lever.

The free end of the guard is guided and held rigid in a vertical plane by the guard arm 2|. For this purpose this guard arm extends into the guide slot 23A provided between the guide rails 23, 23. These rails are supported at one end on the supporting member or upright l2 and at the other endby a similar supporting member 24.

travel of the guard is short and the support at one end by the supporting member I2 is sufficient to hold the guide rails rigid. The guard arm 2| in its movement in the guide slot 23A thus guides the gate structure in a straight line movement and by its engagement with the sides of the guard rails assists in holding the gate structure rigid.

The guard arm is longer than the height of the gate structure and, as above pointed out, is adjustable in the guide block [8 so that it can be made to variably project below the gate structure The latter support may be dispensed with if the member or upright 12 and its companion 2d are provided with spaced holes 32, 32 for the bolts 33, 33 to pass therethru and clamp the uprights to the head with the guard properly located relative to the danger zone between the dies in the press. r

In presses where the table 2 is stationary and the head 3 is moved by the ram, the mounting of the guard is simply reversed by fastening the supporting member l2 to the stationary table and the bracket 29 with its cam rod 21 to the I movable head.

in order to protect any danger area below the V gate structure from which the hand or arm. of the operator must be displaced on'the operation of the guard. The guard arm is also adjusted so that its lower endextends below the top of the bed 2 and is located in front thereof. This keeps the guard arm and gate in a vertical plane in forced toward the dies.

For the operation of the guard the extension arm I6 carries the bracket 26 which is: swiveled to the outer end thereof and is provided with a' pair of parallel rollers 25A suitably spaced from each other. The cam rod 21 projects thru the bracket 26 between the rollers 26A and is moved up and down therein for the operation of the safety guard as willpresently appear. The cam rod has a uniform, square cross section thruout its length and is bent to provide the angular cam 28 intermediate the ends thereof.

The camurod is adjustably clamped in place in the bracket 29 which is attached to the moving table 2 of the press. For this purpose the free end of the bracket is provided with the channel 29A to have the cam rod slidably held in place therein by means of the cover plate 30. Set screws 3| in the side of thebracket are adapted to engage the cam rod and adjustably hold it fixed therein.

The cam section in the cam rod is so arranged that the upper straight section of the rod is thereby laterally offset from the lower straight section of the rod so that on the vertical movement of the cam rod theroller bracket is moved laterally and swings the arm l6 for the operation of the levers 8 of the guard. The movement of the upper straight section of the cam rod thru the roller bracket holds the arm 16 stationary in the position in which the gate structure of the guard is held contracted for the inoperative'position of the guard. The movement of the angular cam section 28 of the cam rod thru the roller bracket causes the bracket to turn and be moved laterally to swing the arm l6 for the operation of the gate structure of the guard and the movement of the lower straight section of the cam rod thru the roller bracket keeps the arm l6 fixed with the guard ini ts operated position.

The cam rod can thus be adjusted in its supporting bracket to cause its cam sec'tio'nto ope ate the guard at'the beginning of the movement of the table 2 or at any point in its movement thereafter. The guard may thus be immediately operated and held operated during substantially the entire movement of thetable 2 or the guard may be held inoperative at the beginning of the movement of the table andthen operated and held operated for the remainder ofits movem ent For the purpose of vertically adjusting the entire guard between the mov'able table 2 and; the fixed head 3 of the press, the supporting '20 front of the bed and prevents it from being Of course the safety guard shown and described may be changed, and variations. may be required under certain conditions, therefore,

while some of the constructional details are deemed preferable and I have shown and described them specifically, it is to be understood that I- do not limit myself to such precise construction, but consider that I am at liberty to make such changes and alterations as fairly come within the scope of the appended claims.

I claim: 1 r

1. A safety guard comprising a series of levers pivotally held together in pairs and hingedly connected to form an expansible and contractible gate, fixed pivotal supporting means for the free end of one of the pair of levers at one end of .the gate, movable supporting means for the free end of the other lever of the said pair of levers of the said end of the gate, an arm extension on said lever end held supported on said fixed pivotal supporting means, a movable cam rod engaging 'said arm extension and means for adjustably holding said cam rod for the operation of said armextension.

2.'A safety guard comprising a series of levers pivotally held together in pairs and hingedly connected to form an expansible and contractible gate, fixed pivotal supporting means'for the free end of one of the pair of levers at one end of the gate, movable supporting means for the free end of the other lever'of the said pair of levers of the said endof the gate, an arm extensionon said lever end held supported on said fixed pivotal supporting means, a longitudinally movable cam rod, straight sections forming the 'upper and lower portions of said rod, an angular section intermediate the upper and lower straight sec tions so as to offset one straight section from the other and means carried by said'arm extension for engagement by said cam rod to have the cam rod hold said arm-extension in an inoperative position during part of, its movement, operate said arm during another part of its movement and hold the arm in an operated. position during the remainder of its movement.

3. A safety guard as set forth in claim 2 including means for adjustably holding said cam. rod for permitting change of the movement of said arm extension by said cam rodl. A safety guard as set forth in vclaim'l including supporting blocks carried by the ends of of the machine; 'a' series of leverspivotally held together "in pairs and hingedly connected "to form an expansible and contraotible gate, means for pivotally supporting the free end of one of the pair of levers at one end of the gate to said supporting member, a link mounted to swing on said supporting member and pivotally connected to the end of the other lever of the said pairof levers at the end of the gate, a stop on said supporting member for engagement by said link when the gate formed by the series of leversis in a predetermined expanded position; a pair of parallel guide members carried by said supporting member, a guard arm carried by the ends of the levers of the pair of levers at the opposite end of the gate, said guard arm projecting between said guide members so as to guide said guard arm and said levers.

6. A safety guard as set forth in claim 5 including an extension arm on the lever pivotally supported on said supporting member, a bracket swiveled on said extension arm, a cam rod movable thru said bracket, and means for adjustably holding said cam rod on the movable operating member of the machine to move therewith and cause said cam rod to operate said gate on the movement of said movable operating member.

WILFRID H. SEARJEANT.

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