US1721259A - Strain insulator - Google Patents

Description

July 16, 1929. w. H. PEARL STRAIN INSULATOR Filed Aug 6 1 ATTORNEY,

Fatentecl July 16, 1929.

WILLIAM H. PEARL, or INDIANAPOLIS, NDIANA.

STRAIN INSULATOR.

Application filed August 6, 1924. Serial No. 730,393.

It is the object of my invention to provide a simple strain insulator mounting which can be installed with a minimum of effort and care on the part of the lineman, and which when in place has its parts eifectively interlocked to prevent their accidental separation; and which is inexpensive and easy to manufacture.

In carrying out my invention, Iprovide two mating members, preferably of identical shape so that any two such parts may be used together. These two members have two fingers, one on each member, for projecting into the opposite axial ends of the bore of an insulator, with the fingers desirably overlapping within the insulator bore. Each finger projects transversely from one end of an arm, which in turn projects from a perforated ear which overlaps a similar ear of the mating member so that the perforations register to receive an attaching member, such as a screw-hook or a staple; The two overlapping ears of the two mating members preferably have interlocking parts, such as a finger in one projecting into a hole in the other, which interlocking parts co-operate with the attachin member when the latter is in place in the perforations of the overlapping ears to prevent suflicient relative movement between the two mating members to prevent either their separation or the withdrawal of the fingers from the bore of the insulator.

The accompanying drawing illustrates my invention: Fig. 1 is a plan of a strain insulator mounting embodying my invention. with the insulator and the attaching screw-hook in dot-ted lines; Fig. 2 is a section on the line 22 of Fig. 1; Fig. 3 is a plan of the two mating membersof the insulator mounting, separated; Fig. 4 is an end view of the strain insulator mounting, showing the overlapping of the fingers within the insulator bore, the insulator itself being shown in dotted lines; and Fig. 5 is a section on the line 55 of Fig. 1.

The insulator 10 is desirably of the usual type of porcelain insulators, with an axial bore 11 and one or more exterior circumferential grooves 12; one such groove 12 is shown in the insulator of Fig. 1, and two such grooves in the insulator of Fig. 4. The groove or grooves 12 are to receive in the usual way the wire or wires which the insulator carries.

The insulator 10 is supported on the inwardly projecting fingers 15 of the two mat ing members 16 of my strain insulator mounting. The two members 16 are desirably of identical shape, so that any two such members may be used together. The two fingers 15 project into the bore 11 of the insulator 10 from the opposite ends of such bore, as is clear from Figs. 1 and 1. The adjacent ends of the two fingers 15 desirably overlap to form an oblique joint 17 within the bore 11, desirably at about the middle of such bore. Each finger 15 projects transversely from one end of a supporting arm 18. From the other end of such arm 18 an ear 19 projects laterally on the same side as the arm 15 so that when the fingers 15 overlap, the cars 19 will also overlap, and the two mating members will form a complete inclosure. The ears 19 desirably overlap in the reverse Way from that in which the fingers 15 overlap; and are so arranged. that theear-faces which abut are in about the medial longitudinal plane of the arms 18 and fingers 15.

The ears 19 are provided with holes 20,

which register when the ears 1.9 of two of the mating members 16 are put together, as is clear from Figs. 2 and 5. In addition, each ear 19 is provided with a lug 21 projecting from that ear-face which abuts against the mating ear, and with an opening 22 suitably arranged to receive the lug 21 of a mating member when the two members are put together with their holes'2O in registry and their fingers 15 overlapping. The lugs 21 and holes 22 are eccentrically located with respect to the holes 20, so that when they are in engagement they prevent turning of the two members 16 relatively to each other about the common axis of the two registering holes 20. Conveniently the hole 22 is merely a lateral extension of the hole 20, at one side, as that facilitates manufacture. In addition, the lugs 21 are preferably of somewhat greater length than the thickness of the cars 19, as is clear from Fig. 5, to insure against their separation from the holes which receive them.

lVhen two mating members 16 are put together with their holes 20 in registry and their fingers 15 overlapping, a suitable attaching member may be inserted through the registering holes 20 to hold them in registry and to furnish the support for the structure as a whole. Such an attaching member may swa the insulator 10, by the same motion putting the two cars 19 in overlapping position; and then he swings the two ears together so that thelugs 21 project through the holes 22, with the holes in alinement. Then he inserts the attaching member25 through these registering holes 20 of the assembled unit composed of the two mating members 16 and the insulator 10.. If the attaching member is a screw hook, it may already have been screwed into the support on which the strain insulator is'mounted.

When the device is thus assembled and mounted, it remains in place, with its various parts in proper relative position, under all conditions encountered, and can only beta-ken down by direct intention. The interlocking provided by the attaching member 25 and the lugs 21 and holes 22 prevents the fingers 15 from being withdrawn from the bore of the insulator. Such withdrawal can only be obtained by first separating the attaching member 25 from the pair of members 16. If the wire that the insulator supports should break, the unit comprising the two members 19 and the insulator 10 merely drops down by gravity, while remaining on the hook 25,

without letting the insulator 10 fall off. If

the insulator 10 is broken for any reason, the

overlapping fingers 25 catch the wire which was fastened in the groove 12 of the insulator, and thus keep it from falling.

I claim as my invention 1. Alstrain insulator mounting, comprising two mating members having fingers arranged to extend into an insulator bore from opposite ends thereof; said two mating members being arranged to overlap each other outside of said insulator, and the overlapping parts of said members being provided with registering holes for receiving an attaching member, the overlapping portions of said two mating members being provided with inter-- locking parts for preventing relative turning of said two members.

2. A strain insulator mounting, comprising two substantially similar members, each of said members having a head portion and a finger portion, said finger portions being adapted to overlap, each of said head portions being provided with a locking lug and with a depression for receiving the locking lug on the other of said members.

8. A strain insulator mounting, comprising two mating members adapted to be assembled in. substantially coplanar relation, said two'members having portions which owrlap when the members are assembled, said overlapping portions being provided with locking means for preventing relative movement of said two members in their plane, and said members having extending portions adapted to receive and hold between them an insulator. V

1. A strain insulator mounting as set forth in claim 3 with the addition that the overlapping portions of said members are provided with registering holes for receiving an attaching member.

In witness whereof, I have hereunto my hand at Indianapolis, Indiana, this 2d day of August, A. D. one thousand nine hundred and twenty-four.

WILLIAM H. PEARL.

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