US2025346A - Releasing clamp - Google Patents

Description

I Dec. 24, 1935. K HAWLEY 2,025,346

RELEASING CLAMP Original Filed July ll, 1929 Z l /o f w am/w l l if I A5 2 l A? /Z /6 w 6 V p /0: 0 1

Patented Dec. 24, 1935 UNITED STATES PATENT OFFICE RELEASING CLAMP Original application July 11, 1929, Serial No. 377,565, now Patent No. 1,916,950. Divided and this application August 30, 1932, Serial No.

8 Claims.

This application is a division of my co-pending application for patent for Releasing clamps, now Patent No. 1,916,950 filed July 11th, 1929 and given Serial No. 377,565.

The invention relates to means for suspendingthe conductors of current transmission lines and has special reference to suspension clamps.

It is well known that it is customary to support transmission line conductors by means of clamps located at the bottom of strings or chains of insulators which are in turn hung from towers located considerable distances apart. It is a fact that snow or ice and sleet frequently collects on the conductor at one side of a point of suspension but not on the other side as for example at the edge of a storm area or when there are differences in temperature or other climatic conditions along the line. Furthermore it frequently occurs, especially in mountainous sections that one or more spans of the conductor may be subjected to the influence of high winds. In either event, and under other circumstances of a more or less analogous nature which may readily suggest themselves, it is apparent that there is an excessive strain at one side of a supporting tower and unless the tower is of excessively heavy construction, that is to say heavier than would reasonably be provided, there is a certain danger that the tower may be pulled out of plumb. Of course under such circumstances the insulator strings are also pulled out of place and damage thereto may easily occur.

It is with the above facts in view that I have devised the present invention which has for its general object the provision of a conductor clamp capable of automatically releasing or at least decreasing its grip upon the conductor upon the occurrence of an excessive strain at one side or the other of the clamp and whatever support it is hung from.

An important object of the invention is to provide a releasing clamp which will under ordinary conditions exert a powerful clamping action upon the cable but which is so constructed as to permit the cable to slip through until the strains have become equalized.

Another object is to provide a releasing clamp of this type which may regain its clamping ability or re-exert its clamping action upon the cessation of the abnormal strain previously operating to bring about the releasing action.

Another important object is to provide a clamp embodying cam means for effecting the release.

Yet another object of the invention is to provide a clamp having an element adapted to be temporarily distorted so as to release the grip upon the conductor so that the latter may slip through and adjust itself, it being also a feature that the distorted element may reassume its natural or normal condition so that the device may regain its clamping function without it being necessary to make any repairs or replacements.

Another important object of the invention is to provide a clamp of this type which does not depend on springs for its holding action but which has, on the contrary, positive means for applying a clamping force to the conductor.

An additional object is to provide a device of this type which will consist of but a few parts, 15 certain of which are more or less standard among insulator manufacturing companies, and which will consequently be inexpensive to make in ad- .dition to being easy to apply or install, positive in action, efficient and durable in service, and a general improvement in the art.

To the attainment of the foregoing and other objects and advantages, the invention preferably consists in the details of construction and the arrangement and combination of parts to be hereinafter more fully described and claimed, and illustrated in the accompanying drawing in which:

Figure 1 is a side elevation of a. clamp constructed in accordance with my invention and showing it in normal position upon a conductor,

Figure 2 is a longitudinal section with the released position indicated,

Figure 3 is a central cross sectional view,

Figure 4 is a detail view of the upper clamping member.

Referring more particularly to the drawing it will be observed that I have shown a clamp for supporting a conductor I, the clamp embodying a main or lower clamping member 2 having a transversely curved seat 3 for the conductor, this seat being, moreover, curved longitudinally so that the ends thereof will flare away from the conductor to avoid bringing-any bending strains thereon such as might occur in the event of vibration or dancing of the conductor. This lower clamping member 2 is represented as provided at one side with bosses 4 having vertically extending holes 5 therethrough for the reception of clamping bolts to be described. At its center the member 2 is shown as provided with oppositely extending lateral trunnions 6 which are preferably integral and which are represented as having downwardly elongated heads I.

Cooperating with the lower member or body 2 b5 to be explained.

The holding means is here represented as comprising J-bolts II which have their. shanks extending through the holes 5 in the bosses 4 and which have their hooked ends overlying the reduced extensions Ill. Beneath the bosses these J-bolts are provided with nuts l2, it being preferable that spring washers |3 be interposed between the nuts and the undersides of the bosses to prevent accidental unscrewing of the former and. also to provide a very limited yieldability.

The suspension means is here represented as comprising a pair of links I 4 straddling the member 2 and formed with elongated openings l5 for the passage of the'trunnions 6, the downwardly prolonged heads I of these trunnions projecting beyond the lower ends of the openings l5 so as to prevent lateral displacement of the links with respect to the clamp when in service. At their upper ends the links may be apertured as at 16 for connection with a suspension element, not shown, at the lowerend of a string or chain of connected insulators. The axis of the trunnions B is preferably at substantially the longitudinal center of the conductor, which is the logical and most advantageous location of the pivot. Above the openings t5 the links are provided at their inner faces'with' flat ledges H which cooperate with pairs of lugs l8 projecting laterally from the opposite edges of the clamping member 8.

The device is applied to the conductor by placing the clamping members 2' and 8 below and .above the conductor, respectively, and applying the J-bolts ll. Suspension is effected by engaging the links M upon the trunnionst and then connecting the links with the string of insulators from which the conductor is to be suspended. When the nuts [2 are tightened the upper member 8 will be drawn down into clamping relation to the member 2 and conductor i so that there will beanadequate grip upon the latter. Under normal circumstances the ledges or shoulders I! are spaced slightly below the lugs 68 as clearly indicated in Figures 1 and 3- so that there will be no wear on these parts during limited swaying or swinging movement of the clamp with respect to the suspension links.

In the operation, it is apparent that upon breakage or overloading of the conductor at one side or the other of the clamp the insulator string, not shown, and the clamp carried thereby will swing lengthwise of the conductor, whereupon the ledges I! will engage against one or the other pair of lugs l8 and apply upward pressure upon the upper clamping member, the pressure obviously being greater at one end than at the other. The upper clamping member then fulcrums upon or within one of the J-bolts II and presses upwardly against the other with such force as to spring it, flex or distort' it out of its normal condition, thereby relieving the pressure exerted upon the conductor by the upper clamping member and permitting the conductor to slip through until a state of equilibrium or balance of strain has been established, subsequently to which the natural resilience of the flexed or distorted J-bolt will cause it to resume its natural condition re-exerting the clamping action on the conductor- From the foregoing description and a study of the drawing it will be apparent that I have thus provided a very simply constructed and easily installed clamp which will have the necessary holding action under normal conditions and which will be capable of automatically releasing in the event of an unusual strain coming upon the conductor at one side or the other of the clamp. It is believed that the construction, operation and advantages will be readily apparent to one skilled in the art without further explanation.

While I have shown and described the preferred embodiment of the invention, it should be under stood that the disclosure is merely an exemplification of the principles involved as the right is reserved to make all such changes in the details of construction as will widen the field of utility and increase the adaptability of the device provided such changes constitute no departure from the spirit of the invention or the scope of the claims hereunto appended.

Having thus described the invention, I claim:

l. A clampcomprising' a pair of clamping members, a pair of bolt means for securing the samein clamping relation upon a conductor, suspension means, and cooperating means on the suspension means and one clamping member for distorting and rendering one of said bolt means inefiective.

2. A clamp comprising the combination of a pair of clamping members disposable upon a con-- ductor, bolt means securing said members in clamping relation, suspension means connected with one of said clamping members, and cooperating means on the suspension means and the other of said clamping members for flexing one of said bolt means and thereby decreasing the clamping action thereof.

3.- A clamp comprising a pair of clamping members, bolt means securing said clamping members in clamping relation upon a conductor, suspension means, and cooperating means on the suspension means and the other clamping member for flexing one of the bolt means whereby said other clamping member may fulcrum upon the other bolt means. I

'4. A clamp of the character described comprising a lower clamping member, an upper clamping member, bolt members for securingsaid clamping membe-rs upon a conductor in clamping relation thereto, suspension means, and cam means operable upon movement of the suspension means with respect tothe lower clamping member for temporarily distorting one of the bolt members and decreasing the clamping action.-

- 5. A clamp of the character described comprising upper and lower clamping members, bolt members securing said clamping members" in clamping engagement upon a eonducton suspension means, and cam means on the suspension means engageable with the upper clamping member upon pivotal movement of the suspension means with respect to the clamping members for flexing one bolt member and rocking the upper clamping member upon the other bolt member for decreasing the clamping action.

6. A clamp of the character described comprising a lower clamping member having bosses thereon, an. upper clamping member having lateral projections at opposite sides or its transverse center, bolts passing through the bosses and each embracing the upper clamping member for maintaining both clamping members in clamped engagement upon a conductor, suspension links pivotally connected with the lower clamping member, and cam elements on the suspension links engageable with certain of said lateral projections upon pivotal movement of the links with respect to the clamp for forcing one end portion of the upper clamping member upwardly and distorting one of said bolts upwardly.

7. A conductor supporting clamp comprising an assembly of clamping members disposable upon a conductor, securing means for holding the assembly together, suspension means pivotally connected with the assembly, and means on the suspension means coacting with one of the clamping members for temporarily distorting one of the securing means for relieving the pressure exerted by the assembly upon the conductor.

8. A conductor supporting clamp comprising a lower clamping member and an upper clamping member adapted to receive a conductor between them, J-bolts connected with the lower clamping member and overlying the upper clamping mem ber, suspension means pivotally connected with the lower clamping member, and cam means operable upon swinging movement of the clamping members with respect to the suspension means for forcing one end of the upper clamping member upwardly for temporarily distorting one of the J-bolts and relieving the clamping action.

KENT A. HAWLEY.

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