US1274612A - Press-guard. - Google Patents

Description

G. H. SEARS.

PRESS GUARD.

APPLICATION mm AUG.23. I916.

Patented Aug. 3, 1918 3 SHEETS-SHEET I.

WITNESSE f G. H. SEARS PRESS GUARD.

APPLiCATION FILED aueza mm 1 ,274,61 2. lut'vntod Aug. (3, 1918.

WITNESSES: INVENTUR M mi [Zea/ yz I)?! I.) A TTUHNE n;

" ing to be sides in certain 'ment of UNITED STATES PATENT OFFICE.

BY MESNE ASSIGNMENTS,

0F ONE-HALF T0 CHARLES J. PEMBROKE AND ONE-HALF TO FRANK KEIPER, BOTH runes-GUARD.

Specification of Letters ratent.

Patented Aug. 6, 1918.

Application filed August 23, 1918. Serial No. 116,424.

) 1 '0 all whom. it may concern.

Be it known that I, GEORGE H. SEARS, of Rochester in the county of Monroe and State of ew York, have invented certain new and useful Improvements in Press- Guards; and I do hereby declare the followa full, clear, and exact description of the same, reference being bad to the accompanying drawings, forming a part of this specification, and to the referenceaulmerals marked thereon.

y present invention relates to machinery and more particularly to punch presses and similar machines that are intermlttently operated under the control of a workman in which there is danger of injury to the latters hands due to the insertion or removal of the workpieces acted upon by the rain or dangerous element of the machine, and it has for 1ts object to provide an automatic guard for ejecting the arm or hand from the dangerous region and blocking its entrance thereto, which guard will be of cheap and simple construction and convenient and cilicient in its operation. The invention is directed in part toward making the guard mechanism accessible and also readily displaceable for purposes of adjustment and also to allow the occasional operation of the press independently of the safety devices.

0 these and other ends the invention reimprovements and combinations of parts all as will be hereinafter more fully described, the novel features being pointed out in the claims at the end of the specification.

In the drawin Figure 1 is a flint elevation of the up er portion of the punch press provided wit a guard or safety device constructed in accordance with and illustrating one embodimy invention;

Fi' 2 is a horizontal section taken substantlally on the line 2-2 of Fig. 1;

Fig. 3 is a vertical section taken substantially on the line 33 of Fig. 2 with the parts in the position occupied when the guard is in the operative dotted line position of Fig. 1;

Fig. i is P q Fig. 5 'is a detail View showing the devices for actuating the guard through the medium of the ram;

a side elevation of the entire Fig. 6 is a section taken substantially on the line 6-6 of Fig. 5, and Fig. 7 is a section similar to Fig. 6 but with the parts in another position.

Similar reference numerals throughout the several figures indicate the same )arts.

The punch press in connection wit which I have illustrated my invention com rises an upper frame 1 above a bed 2, the rame being provided with guides or ways 3 in which operate the slides 4 of a ram 5 havin a journal block 6 connected to the crank of the shaft 8 at the top of the frame so that the ram reciprocates back and forth toward and from the bed 2 upon each revolution of the shaft. 9 indicates a male die carried by the ram 5 and 10 a female die on the bed 2, 11 being the die clamps for the stationary die. The shaft 8 is driven by a drive wheel 12 through the medium of a clutch 13. The clutch is thrown in by a pull on a rod 14 (Fig. 4) connected thereto at its 11 per end and connected at its lower end to a oot treadle 15 pivoted at 16to the lower frame 17 of the machine which lower frame supports the upper frame 1 and bed 2. Each depression of the treadle 15 and actuation of the clutch 13 joins up the drive wheel and shaft for one reciprocation of the ram 5, as will be understood. this being the usual general mode of operation of presses of this kind.

In the practice of my present invention, I provide a bridge member 18 carried stationarily by the frame 1 to span the Ways 3 and the ram operating therein and at a referably central point on the bridge is pivoted at 19 a guard arm 20 carrying a vane 21 the normal position of which and of the arm is shown in full lines in Fig. 1. Through mechanism hereinafter described, upon each ownward movement of the ram 5 toward the bed 2 the arm 26 is automatically swung to the rightand with it the vane 21 to the dotted line position of Fig. 1 so that if the 'operators arm or hand is in the dangerous it will be e ected of operating the clutch 13 and will reach that proac of the ram to the bed 2 or of the dies carried, respectively, thereby. In the present instance, this connection, comprises a pull rod or link 22 connected to the treadle 15 and to a bell crank lever 23 (Fig. 4) pivoted at 24 to the frame 1. The other arm of the bell crank is connected by a link 25 to a second bell crank 26 (Fig. 2) pivoted at 27 and provided with a socket 28 in its other arm. Slidably received within this socket 28 is the stem 29 of a block 30 pivotally connected at 31 to a link 32 that is pivoted at 33 (Fig. 3) to an arm 34 on the hub 35 of the guard arm 20 or its shaft or pivot 19.

It will be seen from the above that each time the treadle 15 is depressed to throw n the clutch 13 the guard arm 20 will immediately be thrown in the operative position through the pull on the rod 22 and connected parts and thereafter and not until this has occurred will the ram 5 descend.

A latch 36 pivoted at 37 to the bridge member 18 is utilized to lock the guard in operative position so that releasing the treadle 15 before the ram has completed its movement will not cause the guard to withdraw just at the time it is needed. The latch is normally drawn to the right by a spring 38 so that a finger 39 thereon will engage above a locking shoulder 40 on a link 41 which, with a link 42, forms a toggle that is straightened out when the pivot 19 of the guard is rocked to carry the latter to operative position as in Fig. 3. The link 41 is pivoted to the arm 34 at 43 and to the link 42 at 44 and the link 42 is in turn pivoted at 45 to the bridge piece 18. A finger 46 on the latch 36 pro eCts downwardly below the bridge to permit a manual release of the latch but in the normal workin of the device, the latch is automatically tripped as the dies 9 and 10 come together (and the danger to the operator is past) by a cam shoulder 47 on a stop plate 48 fixed to the ram 5 to move therewith. This cam 47 comes in contact with the rearward boss 49 on the latch 36 and throws thelatch downwardly and to v the left so that the finger 39 disengages from the shoulder 40 on the toggle and allows the latter to move upwardly and the guard arm pivot 19 to revolve to the right again as the guard arm takes up its inoperative position to the left. The guard arm is operated to and normally held in its tion by a spring 50 (Fig. '4) that acts through the link 14 to raise the treadle 15. As the treadle is raised it pushes upwardly on the link 22 and as previously described, this lin is connected by a series of links and lovers to inc guard arm.

It is advisable to have a direct acting means for operating the guard arm by the Eos1tion 1n advance of the near ap-.

' figures.

inoperative posithat if the clutch 18 should and cause the reciprocaeat upon a single delo, the dangerous re- Would still surely be the operators hand. secured to the ram ram itself so stick, for instance, tion of the ram to re pression of the tree gion between the dies rendered inaccessible to To this end, a block 51 5 is provided with a T slot or'way 52 in which the sto plate 48 is adjustably held by a bolt 53. in this way is confined a stop arm 54 (Figs. 6 and 7) that yields rearwardly on a pivot lo 55 that enters a recess in rear of plate 48 ut is normally thrust forwardly by a leaf spring 56 in rear thereof. The upper end of the stop arm is formed with a hook or shoulder 57 that is normally held by a spring in a position to engage within a groove 58 in the upper ed e of the toggle link 42, asshown in Fig. 6. is the ram descends, this engagement takes place at the proper time if the treadle connection, previouslydescribed, has failed to operate the guard arm 20 and the to gle is straightened out from the position 0 Fig. 5 to that of Fig. 3 which operates the guard automatically into operative position before the ram can reach a point at which it would be dangerous for the o erators hands. The guard is operated by t e engagement of the stop hook with the toggle in advance, of course, of the tripping of the latch 36 by the cam 47 striking the boss 49. Both the cam 47 and the stop arm 54 being carried on the adjustable plate 48, they are adjusted in unison and the interval between their succcssive operations is maintained constant throughout adjustments for differences in thethrow of the ram 5.

n the return or upward movement of the ram, the cam stop 47 that has passedthe boss 49 in tripping the latch 36 rides over it again deflecting the latch idly and very slightly as the finger 39 rides against the under side of link 41, as shown in Fig. 5 and as soon as the toggle is released from the latch on the down trip, the latch is held partially restrained toward the left in the The contact of the stop shoulder 57 with the toggle isalso a slip-olf connection that causes only a momentary connection be- The operative position of the latch 36 is limited by a stop pin 60 fixed on the bridge 18 that limits its throw in this direction.

For the purpose of adjusting themechanism of the press itself; adjusting the guard actuating mechanism: adjusting the mechanism of the ram that cooperates with the guard actuating mechanism; disconnecting the guard mechanism entirely when required as, for instance, in blanking. and in similar connections, I find it desirable to have the safety device displaceable as a unit and to this end the bridge piece 18 is connected to brackets 61 and 2 on the press frame 1 by pins 63 and 64. one of which is removable to allow the bridge to pivot on the other and be swung laterally so that it both itself rendered accessible with the niechanism mounted thereon and the parts of the press in rear are also exposed. Tn the prcsent instance, 63 is a pivot pin extending between ears on the brackets and 64 is a 1' movable pin. The only constant connection between the guard actuating mechanism on the bridge and the mechanism of the press is at the bell crank 26 but as before described, the stem 29 (Fig. 2) can be sildably withdrawn in a for ard direction from the socket E28 and this occurs automatically as the bridge is swung forwardly while when it is moved back in place, the stem 29 can be readily reinserted. The other cooperating elements on the press and bridge respectively, as for instance, the stop arm 54 and the toggle 41%), rcaline themselves without special attention.

I claim as my invention:

1. In a safety device for punch presses, the combination with a press comprising a frame, a bed and a ram movable in the frame toward and from the bed, of a displaeeable bridge mounted on the frame to span the ram, a movable guard carried by the bridge to block the interval between the bed and ram, and mechanism also carried by the bridge for operating the guard, said mecha nism being adapted to cooperate with the mechanism of the press when the bridge is in place to cause'an actuation of the guard with each actuation of the ram.

2. In a safety tlt\ e for punch presses, the combination with a press comprising a frame, a bed, a ram movable in the frame toward and from the bed and controlling mechanism for the ram, of a displaceable bridge pivotally mounted on the frame to span the ram, a movable guard carried by the bridge to block the interval between the bed and ram and mechanism alsocarried by the bridge for operating the guard embody ing a coupling mcmher connecting said mechanism to the ram controlling mechanism when the bridge is in ilace to cause an actuation of the guard witi each actuation of the ram, said coupling member being adap d to detach itself as the bridge is swung out of position on its pivot.

ii. in a safety device for punch presses, the combination with a press comprising aime, a bed, and a ram movable in the frame toward and from the bed, of a movable guard adapted to block the interval between the bed and ram, guard actuating devices eomprising a toggle connected to the latter and to the frame, a device on the ram adapted to cooperate with the toggle to 0perate the guard during the descent. of the ram and a latch engaging with the toggle to lock the guard in operative position.

i. In a safety device for punch presses, the combination with a press comprising a frame. a bed, and a ram movable in'the frame toward and from the bed, of a movable guard adapted to block the interval between the bed and ram, guard actuating devices comprising a toggle connected to the latter and to the frame and a device on the ram having a slip-ofi' engagement with the toggle to prod nee a momentary operation of the guard by the ram at a predetermined point in the travel of the latter.

5. In a safety device for punch presses, the combination with a press comprising a frame, a bed, and a ram movable in the frame toward and from the bed, of a movable guard adapted to block the interval between the bed and ram, guard actuating devices comprising a toggle connected to the latter and to the frame. a device on the ram adapted to cooperate with the toggle to operate the guard during the descent of the ram, a latch engaging with the toggle to lock the guard in operative position, and a. device on the ram arranged to trip the latch at a later point in the descent of the ram.

6, In a safety device for punch presses, the combination with a press comprising a frame, a bed, and a ram movable 'in the frame toward and from the bed, of a movable guard adapted to block the interval between the bed and ram, guard actuating devices, a device on the ram having a slip-off engagement with the said guard actuating devices to operate and then clear the guard during the descent of the ram. a latch'for locking the guard in operative position, and a device on the ram arranged to trip the latch at a later point in the descent of the rain.

7, In a punch press, the combination of a press having a frame and a ram reciprocating therein. said frame having uprights, one on each side of the mm, a bridge extending between said uprights, said bridge bein hinged to one of the uprights and latched to the other upright, a guard mounted on said bridge to swing in a vertical plane in front of the ram. said bridge bein capable of being released on one side and swung around carrying said guard therewith away from the ram.

8. Tn a punch press, the combination of a. press having a frame and a ram reciprocating therein, said frame having uprights, one on each side of the ram, a bridge extending between said uprights, said bridge being the ram, means for actuating said guard, hinged to one of the uprights and latched to said means detaching itself from the guard the other upright, a guard mounted on said as the bridge is swung away from the ram. 10

bridge to swlng in a vertical plane in front GEORGE H. SEARS. 5 of the ram, said bridge being capable of be- Witnesses:

ing released on one slde and swung around CLAYTON L. JENKS,

carrying said guard therewith away from P. WESLEY HART.

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