US2053976A - Detent means for cable drums - Google Patents

Description

- I Sept. 8, 1 936. F AHL 2,053,976

DETENT MEANS FOR CABLE DRUMS Original Filed March 1, 1933 mlllmmn Inven%07; I FRANK E. STAN-L Patented Sept. 8,

UNITED STATES PATENT OFFICE DETENT MEANS FOR CABLE DRUlWS Original application March 1, 1933, Serial No. 659,113. Divided and this application July 6,

1935, Serial No. 30,180

2 Claims.

My invention relates in general to hoist drums, and particularly to means for stopping the rotation of the drum when the cable carried thereby has become substantially unwound therefrom.

This application is a division of application Serial No. 659,113, filed March 1, 1933 upon Means for preventing reverse winding of a cable on a drum, which issued November 13, 1934 in Letters Patent No. 1,980,935.

It is well known to those skilled in the art that when operated a wire rope drum hoist, there is a tendency for the operator to keep revolving the drum after the last turn of cable has been unwound therefrom, thereby causing the cable to start winding upon the drum in the reverse direction. This is not only liable to cause serious damage to the hoist or to the load being handled, but such a condition makes the cable unfit for further use, since when hoisting cable is wound in the wrong direction upon a drum, it is kinked in such a manner that the kink cannot be removed.

The principal object of my invention has been to provide means for positively stopping the drum when the cable has been substantially unwound therefrom so as to make it impossible to revolve the drum any further in a lowering or unwinding direction.

Moreover, my invention does not in any wise affect the normal operation of the hoist and it is automatic in its action.

Furthermore, my invention may be applied to the cable drum of any hoisting apparatus, and it :is so inexpensive that it does not add materially to the cost of the equipment.

The above objects and advantages have been accomplished by the device shown in the accompanying drawing, of which:

Fig. l is a side, sectional elevation of my invention, and is taken on line ll of Fig. 2.

Fig. 2 is a front elevation of the device showing the drum in the position it will occupy when rotated ninety degrees in counterclockwise direction, as viewed in Fig. 1.

Fig. 3 is a fragmentary, sectional view showing a position of the detent lever when the first turn of cable is being wound upon the drum.

My device comprises a drum l which is rigidly mounted upon a suitable shaft II. The shaft II is, of course, mounted in suitable bearings l2 each carried by a bracket [3.

The drum is provided with a body 15 and end flanges l6 and H. The body of the flange is preferably provided with a helical guide groove l8.

The cable 20 has its inner end passing into the body I of the drum through an opening 2| formed at the inner end of the guide groove l8, near the flange ll. So as to carry the cable smooth into the interior of the drum, the guide groove terminates in an inwardly curved wall 22. A suitable anchor 23 is provided on the extreme inner end of the cable and this serves to secure the end of the cable to the drum.

The body of the drum is formed with a recess 25 which is so located that it lies in the first turn of the guide groove l8 and underneath the first turn of the cable when wound upon the drum. A detent lever 26 is arranged to lie in the recess 25 and is pivotally carried by means of a pivot pin 2i secured to the body. The outside surface of the detent lever is preferably curved so as to be concentric with the guide groove l8 when it lies in the recess 25, so that the cable, as it is Wound around the first turn of the groove, will be supported by the lever and the lever will be held within the recess by the cable. The pivot pin 21 is arranged at the end of the recess 25 which is in. the advance when the drum is being rotated to wind the cable thereon. The end of the recess 25 at which the pivot 21 is formed is provided with a shoulder 28 which forms an abutment when the detent lever is in the position shown in Fig. 1, thus preventing the lever from moving farther around upon its pivot.

The bracket I3 is provided with a downwardly extending detent arm 30 carrying a detent lug 3|. The detent lug extends beyond the inner face of the end flange ll of the drum and is engaged by the free end 29 of the detent lever 26 when the lever falls out of the recess 25 and occupies the position shown in Fig. 1.

From the foregoing it will be obvious that when the'drum I0 is rotated in a counterclockwise direction from the position shown'in Fig. 1, and as viewed in that figure, the detent lever 26 will be elevated and will be moved into the recess 25 by gravity, having substantially reached its inner position when the drum has been rotated to the position shown in Fig. 2. Upon continued rotation, the first coil of cable would be laid over the detent lever 26 as it lies within its recess 25, as clearly shown in Fig. 3, thus holding the detent lever within the recess and preventing its falling out of the drum. When, however, the drum is rotated in a clockwise direction to unwind the cable, and the last turn of cable on the drum has been reached, as shown in Fig. 3, further clockwise movement will cause the detent lever to be uncovered and bring it to the position shown in Fig. 2. When in this position, further rotation of the drum will permit the lever to move by gravity out of the recess and to engage with the detent lug 3| when the free end 29 of the lever has been lowered, by the continued rotation of the drum, to the position where it will contact with such detent, as clearly shown in Fig. 1. Further clockwise or unwinding movement of the drum is thereby stopped and all possibility of rewinding the cable upon the drum in opposite direction with the consequent kinking of the cable. is positively prevented.

Obviously, some modifications of the details herein shown and described may be made without departing from the spirit of my invention or the scope of the appended claims, and I do not, therefore, wish to be limited to the exact embodiment of the invention as herein shown and described.

Having thus described my invention, what I claim is:

l. The combination with a drum and a cable therefor, of detent means for the cable drum, comprising a bearing bracket for the drum, the drum being formed with a recess in its periphery, a gravity actuated latch lever nested in the recess of the drum when held therein by the cable, said lever being pivotally attached to the drum, said cable being engageable with the latch lever to hold the same in inoperative position until the same is substantially completely unwound therefrom, and a detent lug carried by the bracket and engageable with the latch when the same is released from the recess.

2. The combination with a drum and a cable therefor, of detent means for the cable drum, comprising a bearing bracket for the drum, the drum being formed with a recess in its periphery, a gravity actuated latch lever mounted in the recess of the drum and pivotally attached to the drum, said cable being engageable with the latch to hold the same in inoperative position until the sameis substantially completely unwound there'irom, a detent lug carried by the bracket and engageable with the latch lever when the same is released from the recess, and a shoulder 20

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