US1942862A - Slip clamp - Google Patents

Description

SLIP CLAMP Filed July 29', 1930 INVENTOR M4025 ZQ YhFM m Patented Jan. 9, 1934 UNITED STATES PATENT v OFFlCE SLIP CLAMP New York Application July 29, 1930. Serial No. 471,558

11 Claims.

This invention relates to clamps for electrical conductors and particularly to slip clamps.

Transmission lines have consistently grown much heavier during the last several years and these heavy conductors require much larger and more expensive structures for their support. A large part of the expense involved is due to the necessity for designing the structure with sufficient strength to support itself against the heavy load imposed in a longitudinal direction when one or more of the conductors break. These conductors, in extreme cases, have a strength in the neighborhood of 40,000 pounds and are strung with tensions up to about half this amount. The maximum load on the structure occurs relatively infrequently and may possibly never occur, but nevertheless the structure must be able to take care of such loads.

One object of my invention is the provision of a clamp adapted to take care of excessive loads.

Another object is a slip clamp whose clamping action is automatically releasable upon abnormal conditions of stress in the conductor at one side of the clamp.

A further object is to provide a clamp with trip washers adapted to relieve the conductor passing through the clamp of clamping action.

A still further object of my invention is to provide a clamp by means of which a tremendous leverage can be secured about the trunnion of. the clamp whereby the washer can be forced to slide against the friction of the bolting.

Another object of my invention is to provide a clamp which need not be made with a high degree of accuracy and which will receive cables varying as much as 25% in diameter.

Another object is to provide'a slip clamp which is convertible to a non-slip clamp merely by removing the trip washers.

Other and further objects will be understood by those skilled in this particular art or will be pointed out hereinafter.

In the accompanying drawing:

Figure 1 is a side elevational view of a clamp embodying the present invention, parts being broken away for clarity; and

Fig. 2 is a view at right angles to Fig. 1, also having parts broken away.

Similar numerals refer to similar parts throughout the several views.

The general features of the clamp illustrated are the same as those of my copending application Serial No. 471,555, filed July 29, 1930, for suspension clamps, and includes a body member 10 in the form of a U-shaped groove having upstanding side walls 11 and a centrally depressed or cut-out portion 12. The body member also has a strengthening rib 13 extending downwardly from its under surface and the apertured ears 0 14 on either side of the central cutaway portion and extending substantially laterally.

Cooperating with said body member is. the keeper member 15 having a groove opposite that of the body member so as to form a circular pas- 5 sage 16 for a conductor or the like. Extending from the keeper member are the downwardly extending bolt members 17 which pass through the apertured ears 14 in the body member. The central portion of the keeper memberis contoured convexly and is provided with pear-shaped trunnions 18 as shown, over which are irremovably sprung the arms 19 of the yoke or clevis member 20, as understood from my copending application. In the instance shown, the upper end of the yoke or clevis member is provided with a socket member 21 by means of which the same may be hung from a string of insulators or any. other support. As shown in dotted lines, a suitable plate may be provided for making a lateral 30 connection of the clamp to a laterally disposed support.

The yoke arms 19 are provided with extensions or fingers 22 which are shaped as shown in Fig. 1. These fingers are inserted in a slot 23 in trip 5 washer 24, which, as shown, is placed on the bolt members 17 between the apertured cars 14 and the nuts 25. The construction of this trip washer is clear from the drawing and it will be noted that the slot 23 is of greater extent than the thickness 99 a of the fingers 22, thereby allowing a certain amount of play or freedom of movement so that the whole yoke can pivot or swing a certain amount before the fingers come in contact with the trip washer.

Additional trip washers 26 are used and these latter are similar washers about the size of the nuts 25, but formed with a central upstanding projection 27, having a flat upper surface and which contacts normally with the lower fiat simi- 19g lar surface of the downwardly extending projection 28 of the first trip Washer. These projections as already stated and as shown in Fig. l are normally in contact and keep the parts in the position shown. In the event that the conductor 5 becomes broken on one side of the clamp or an exceedingly heavy load is placed only on one side of the clamp, an angular motion of the yoke occurs relative to the keeper member whereby the yoke rotates somewhat about the trunnions causing, under proper circumstances, the fingers 22 to come in contact with the trip washer as will be understood clearly from Fig. 1. This forces the trip washer longitudinally sliding its downwardly extending projection 28 relative to the projection 27 on the other trip washer 26. If the movement is enough, that is, if the forces setting up the movement are strong enough, these two projections will override each other and become horizontally aligned and the whole body member will drop relative to the keeper member a predetermined amount, which in the present case, would be the thickness of one of the projections 28 or 2'? on the trip washers l4 and 26. This relieves the cable of all clamping and permits it to slide relatively freely through the hole 16 between the body and keeper members, thus relieving the structure from which the clamp is supported from undue longitudinal stress.

The downwardly extending bolt members 17 are unitary with the keeper member as are the apertured ears 14 unitary with the body member. Said bolts pass through said ears and on the lower ends of the bolts the nuts 25 and locking members 29 are placed in the usual manner. The extreme ends of both the keeper and body members flare slightly for the purposes explained in my aforesaid copending application. Suitable lock washers 30 may, of course, also be used in addition to the locking members 29, which in this case, may be suitable cotter pins or other locking pins extending through the ends of the bolts which may also be provided with the guide tips 31 as understood from my copending application.

The slip clamp as above described and illustrated may, if so desired, be converted to a nonslip clamp, merely by removing trip washers 24 and 26 whereby there is secured. a clamp along the lines of that of my copending application. Conversely, suitableclamps of the non-slip type may be converted into slip clamps according to the present invention by the appropriate provision of trip washers 24 and 26.

Various modifications and substitutions of the various elements can be made, without departing from the spirit and scope of this invention as par: ticularly delineated in my aforesaid copending application.

I claim:

1. In a cable clamp having body and keepei members and means for securing them together so as to clamp a cable therebetween, a trip washer, having a slot therein, interposed in said securing means, and a portion of said clamp projecting into said slot adapted to actuate said washer to cause the same to drop downwardly and thus to release clamping pressure on the cable within the clamp.

2. A clamp comprising a body member, a keeper member associated therewith, trunnions on said keeper member, a yoke sprung over said trunnions, means for securing said keeper and body together, a trip washer interposed in said securing means, having an aperture, a finger on said yoke member projecting into said aperture, a second trip Washer contacting with saidfirst washer, and means for disengaging said washers.

3. In a clamping construction, a plurality of trip washers having contacting projecting portions, and means to disengage said portions thereby releasing clamping pressure on a mem ber within said clamping construction.

4. In a clamp having a body member and a keeper member bolted together in clamping relationship, a trip washer associated therewith, a second trip washer engaging said first trip washer, and means for automatically disengaging said washers under abnormal conditions to relieve the clamping pressure on a member within said clamp.

5. A slip clamp adapted to conform to abnormal conditions including a plurality of trip washers relatively slidable under said abnormal conditions, and means actuated by said abnormal conditions to effect said sliding action.

6. A slip clamp adapted to conform to abnormal conditions including a plurality of trip washers having relatively slidable contacting prominences, and means for aligning said prominences and thus relieving clamping pressure on a member within the clamp.

'7. A clamp consisting of upper and lower clamping members, means irremovably associated with said upper member for suspending said clamp, means for clamping a tension member within said clamp, and trip washer means relatively slidable under abnormal conditions for automatically releasing said tension member from clamping action.

8. A clamp consisting of upper and lower clamping members for a tension member, trunnions on said upper member and a suspending yoke irremovably sprung over said trunnions, nut and bolt means on said members for securing a clamping action on said tension member, and relatively slidable trip washer means intermediate of said bolts for automatically relieving said tension member of clamping action upon abnormal conditions existing on one side of said clamp.

9. In a cable clamp of the class described, means for maintaining a cable normally clamped therewithin, and means for automatically and permanently releasing the clamping pressure on said cable under abnormal conditions, said last means including a slotted trip washer which drops to a lower level and introduces a corresponding freedom of movement into the cable clamping means.

10. In a cable clamp of the class described, means for maintaining a cable normally clamped therewithin, and means for automatically and permanently releasing the clamping pressure on said cable under abnormal conditions, said last means including a slotted trip washer interposed in the normal clamping means and adapted to permanently release the normal clamping pressure under abnormal conditions.

11. In a cable clamp of the class described,

means for maintaining a cable normally clamped therewithin, and means for automatically and permanently releasing the clamping pressure on said cable under abnormal conditions, said last means including a trip washer which, when interposed in the normal clamping means, provides a slip clamp and which, when not so interposed, provides a non-slip clamp, the conversion from former to latter being effected by removal of said trip washer from the cable clamp assembly.

RALPH L. JENNER.

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