US1397779A - Power-press - Google Patents

Description

L. L/PFEIFER. POWER PRESS.

APPLICATION FILED JUNE 2O I919.

Patented Nov. 22, 1921.

2 SHEETSSHEET 1.

Leo L. /zi el:

L. L. PFEIFER.

POWER PRESS.

.."PL|CAT|ON FILED JUNE 20, 1919.

1,397,779. Patented N v. 22, 1921.

2 SHEETSSHET 2.

0 Leo L. Pf'ef/er TET QFFHCIE.

LEO L. PFEIFEB, COLUMBUS, OHIO, ASSIGNOR TO THE JOHN W. BROWN MANU- FACTURING CUMPANY, 0F COLUMBUS, OHIO, A CORPORATION OF OHIO.

P@WEB-?RESS.

Application filed .Tune 20,

To all whom it may concern: 4

Be it known that l, LE0 L. Prnrrnn, a citizen of the United States, residing at columbus, in the county of Franklin and State of Ohio, have invented certain new and useful Improvements in Power-Presses, of which the following is a specification.

This invention relates broadly to power presses, and. has particular reference to the mechanism thereof for controlling their operation, the object of the invention being to provide a hand operated clutch controlling mechanism, which, when used in conjunction with a power press embodying a reciprocatory die, will serve to prevent such movements on part of the die as would tend to injure the operator of the press.

Another object of the invention resides in the provision of improved and novel means for controlling the operation of the clutch structure of a power press, said means being of a hand operated character, in order that when the die is being reciprocated, the hands maintained in positions clear of the the traveling die.

of the operator will be occupied in controlling the operation of said means,' and in this manner the hands of the operator will be path of With these and othenobjects in view, as will appear as the description proceeds, the

invention accordingly consists in the novel features of construction, combination of elements and arrangementof parts, hereinafter to be fully described and to have the scope thereof pointed out in the appended claim.

In the accompanying drawings, forming a part of the present specification, and in which similar characters of reference denote like and corresponding parts:

Figure 1 is a front elevation of a power press equipped with the safety control mechanism comprising the present invention,

Fig. 2 is a side elevation thereof,

Fig. 3 is a fragmentary vertical sectional view taken through the clutch structure of the press, v

F 1g. 4 is a side elevation of the structure disclosed'in Fig. 3,

Fig. 5 is a detail perspective view of the controlling mechanism comprising the pres ent invention, and

Fig. e is a detail view of the mechanism for retaining the controlling lever in ole-- vated position,

Specification of Letters Patent.

Patented Nov. 22, 1921.

1919. serial No. 305,691.

frame 2 are guides l, in which are mounted for reciprocation the sides 5 of a die holder 6. In order to effect the reciprocation of the die holder, a crank shaft 7 is rotatably mounted in bearings 8 carried by the upper portion of the frame 2, whereby upon the rotation of the crank shaft, reciprocatory motion will be imparted to the die holder so as to move the latter toward and away from the bed 3. v

In order to edect the rotation of the crank shaft, use is made of a clutch structure 9, which is of ordinary, construction and is so formed as to permit of but one cycle of operation on the part of the die holder under any given operation. The clutch structure 9, per se, does not form the subject matter of the present invention, as other well known devices of equivalent nature may be successfully employed with equal facility in carrying out the aims of the present invention, but inasmuch as the use of the structure 9 disclosed admirably sets forth the operation of the present invention, the following description will be accordingly directed thereto.

Loosely mounted upon the actuating end of the crank shaft 7 is a pulley 10 and in order to connect the latter with the shaft 7 for uniform rotation, said shaft is provided with a longitudinally extending key-wa in which is rotatably positioned a substantially semi-circular key 11, the latter being provided with a depending crank arm 12. A coil spring 13 coiiperates with the arm 12 and tends to rotate the latter so that the key 11 will lie within the key-way provided in the crank shaft and also in a reglstermg key-way 14c formed in the hub of the pulley 10. Obviously, when said key lies within both of said key-ways the pulley 10 and the crank shaft 7 will be splined for simultaneous movement.

However, the tendency on the part of the spring 13 is counteracted by means of a pivoted dog 15, which through the agency of a. spring 16, is normally maintained in the path of movement of the 12, so that as the latter revolves it will'be caused engage with the dog 15 and retained in such position as to cause the key 11 to remain wholly within the confines of the longitudinal keyway formed in the shaft 7. Thus by lowering the dog 15 so that the same will be clear of the arm 12, said spring 13 .may respond to its normal tendency and rotate the key 11, thus enabling the shaft and the pulley to rotate for a single revolution, as it will be manifest that when the dog is releasedfrom engagement with the crank arm 12,and the latter has started on its rotational movement, said dog will return to its normal position under the influence exercised by the spring 16 and will thus be in position to contact with the arm 12 when the latter completes a full turning movement. It will thus be apparent that the structure 9 provides mechanism whereby the die holder 6 will be caused to complete but one cycle of movement under a given operation, and in this manner serves to minimize in uries to the machine operator by preventing undue movement on part of the die holder.

In order to operate the dog 15 so that the same may be released from engagement with the arm 12, prior devices have employed foot controlled means for effecting this purpose. Practice has disclosed, however, that when foot operated devices are utilized. in this connection, the operator is inclined to become careless and accidentally press the foot treadle without having his hands clear of the holder 6. 'III this .manner many accidents have occurred on machines attainin a high productive output. Therefore, t e present invention contemplates the provision of a control mechanism B, which is of such construction as to require both hands of the operator in effecting its successfulmanipulation. Itwill thus follow that with both hands occupied in operating the press at positions relatively remote with respect to the die holder 6, accidents will be greatly minimized.

In its preferred form the mechanism B comprises a pivoted actuating lever 17,

- tends, to force the latter in an upward di-- which is pivoted as at 18 upon the frame 2, and theforward end of the lever is provided with a handle 19 which extends through a vertically disposed slot 20 formed in a bracket 21, the latter-being rigidly. carried upon the forward portions ofthe frame 2. A link 22 is'connected with the lever 17 .inte'rmediately of its pivot 18 and its handle .19, and the upper end of said link .is similarly connected with the stop dog 15, whereby upon. the oscillation of the lever 17 simultaneous movement will be imparted to the dog 15, which latter in, turn controls the operatlon. .of the clutch structure 9. spring 23 coiiperates with the link 22 and rection, in order to retain the handle port1on of said lever in an elevated position connection 22.

The lever 17 is l ocked against movement normally by means of, a latch 24, the latter being slidably mounted within a longitudinal opening 25 formed in the bracket 21. The spring 26 is also positioned within said opening and normally tends to force the latch 24 into the slot 20 so that the latch will underlie the lever 17 and thus retain the latter in a locked position when elevated. In order to release the lever so that the same may be oscillated, the latch 24 is connected with a rod 27, which latter extends horizontally and is supported for sliding movement within the bracket 21 and within a similar bracket'28, located on the opposite side 'of the frame 2, said rod terminating in an offset handle portion 29, whereby the same may be grasped to effect release movements on part of the latch 24.

In operation, movement may be imparted to the die holder by grasping the handle portion 29 of the rod 27, with one hand, so that the latch 24 may be retracted from engagement with the lever 17, thus permitting the latter to rock about its fulcrum 18. The handle 19 is grasped with the other hand, and when the latch has been properly retracted, said lever is forced downwardly and its movement in a similar direction is imparted to the do 15 by reason of the link imparted to the die holder 6, the rotary.

movement of the crank shaft and the reciprocatory movement of the die holder being s hereinbefore explained,-

compensated for by means of the usual pitman theory. After the movement of the die holder has beeninitiated, the-lever 17 is released so that'the same will return to its upward position by virtue of the influence exercised by the spring 23 thereon, this upward movement of the lever also acting to return the dog 15 into the path of movement of the arm 12, thus causing theclutch structure to disconnect the shaft 7 from the pulley .10 after a complete cycle of movement has been effected, this arrest of movement on part of the crank shaft '7, of course, occurs w en the die holder is in its elevated position. The lever. 17 is automatically locked in its upper position by means of the latch 24, whic is provided with a'beveled underface '31, whereby when the lever is forced upwardly by the action of its spring,

A the same will force the latch inwardly until after the lever clears the same, and at this I juncture the latch is again forced outwardly by the influence of its spring 26, so that the flat upper surface of the latch will engage ean-me with the under edge of the lever so as to prevent the downward movement on part of the latter,

From the foregoing description, taken in connection with the accompanying drawings, it will be apparent that an attachment of considerable utility has been provided for power presses and similar automatic machinery, said attachment serving to permit of the expeditious operating of a press and reduces to a minimum the element of physical danger heretofore present in efi'ecting their operation. It will be observed that before the die holder can be reciprocated it is necessary for the operator to remove .both hands from points contiguous to the holder in order to effect the operation of the control mechanism, and it is this fact essentially that serves to render the present invention successful in carrying out its safeguarding aims. In the event of injury to one or the other of the springs 16 and 23, the remaining spring will still function to maintain related parts in operative positions.

What I claim is In a power press, a rotatably mounted actuating shaft, a power delivering element capable of rotating independently of said shaft, a manually operated clutch structure for connecting said shaft and element for rotation in unison, a pivoted stop member cooperative with said clutch structure and normally serving to retain the shaftand power delivering element out of driving relation, a manually operated arm pivoted to the side of the press including a forwardly extending handle, a link between said arm and stop member, a spring cooperative with said link and normally serving to maintain said arm inan elevatedposition and to retain said stop member in engagement with said clutch structure, a spring pressed latch carried by the frontof said press and normally disposed to underlie said arm to prevent oscillation of the latter, said latch including a bevel nose portion and a substantially fiat upper surface, and a slidably mounted actuating rod connected with said latch disposed to extend transversely of said press, said rod terminating in a handle portion disposed in spaced relationship from the handle portion of said' pivoted arm whereby both hands of the operator will be required in efiecting the operation of the clutch operating controlling mechanism.

In testimony whereof I affix my signature.

LEO L. PFElFE-R.

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