US1065190A - Strain-relief device. - Google Patents

Description

T. J. TOBIN. STRAIN RELIEF DEVICE. APPLIOATION mum NOV. 16, 1912.

Patented June 17,1913.

5] wve when v WM/ Wessex aging 1%; :7 F 0 W UNITED STATES PATENT OFFICE.

THOMAS J. TOBIN, 0F ALBANY, NEW YORK, ASSIGNOR TO THE ERYANT ELECTRIC COMPANY, OF BBZDG-EPQRT, CONNECTICUT, A GUBlP-QRATIGN OF CONNECTICUT.

STRAIN-RELIEF DEVICE.

LOGZSAQU,

Application filed November 18, 1912.

To all who/u,M17101! comeem lie it known that l, THOMAS J. T015124, 9. citizen of the United States of America, an l residing; at lllhany, in the county of Albany and State of New York, have in ieinted a certain new and loiploved Slrain Relief Device. of which the "following is a. sjgeci lirration.

My invention refers to that class of (la vices related to electric fittings commonly called st 'ain relievers, and the object of my invention is to provide an efficient device of this character, which isboth cheaply matle and readily adjusted in use. The present (levice in some forms may also be employed as a taho'up cleviee or adjuster for a suspension eorcl.

lo the accompanying drawings, Figure l. is an elevation partly in section of a pendant installation in which my invention is em ployed both in the suspending and in the suspei'nleel fitting: and also illustrating its use in mollifietl form as cord adjuster; Fig. '2 is a plan of my strain relief device in the form used in the rosette shown in Fig. l; Fig". 3 is a plan of the device in the form used in the suspended socket; Fig. 4 is a plan of the device as n'loclifiel for use as a cord adjuster; Figs. 5, t3. 7 and 8 show by way of example various forms which may he given the device to adapt the same for use in various types of fittings.

'lhe presenl strain reliol' rleviee, in its pro l lzll'ttl loxnn comprises a plate 10 of. slightly flexible izmnlaling material such as heavy w et or lihci', of an euilahlc shape. slotted to form a pair of oppositely t'aceil tongues l1, 12. within the ma thereof. the end; oil the tongues coimnmiicating with apertures '13, le which facilitate the adjustment of the device upon the wires 15, 16. F r use in a rosette 1? of the type shown, thecievice is sha -ml as illustrated in Fig. 2 to conform swhslanlially to the inner outline of the cap il of the rosette. Before attaching the wires to the terminals 19, 52 0 of the rosette, they are passed up through the holes 13 and I lol? the strain relief device, and pulled no erally so as displace upwardly the tongues 11 and 12, as shown in Fig. 1.. Sutlieient wire is l. lowed above the plate 19 not only to permit the attachment'of the Wire enZis to the terminals on the base of the rosette but Specification of Letters I'atent.

.iatenlietl June 17, 1913.

Serial No. 731,816.

also in insure sufiieient wire play to permit the plate 1.0 to rest against the inner face of the cap 18 WlillOUt strain on the terminals.

The tlOfi'ilWillll drag of the Wires against, the ends of the tongues ll and 12- tends to force these entls downward. and thus to gri p the wires between the ends of the tongues and the edges of the cuts in the body of the plate 10 which form the tongues. The heavierthe pull upon the Wires the tighter they are clanmed by the tongues. This contlition is reversed at the pendent fitting, here shown as socket 21. The wires are downward through the holes in the plate-'10, here disk shaped to correspond to the interior 0' the cap of the socket. The tongues are displaced (low' wartlly and the weight of the tilting or accidental pull thereon, as in the case of a pendent switch, tends to clamp the wires tightly between the ends of the tongues and. the edges of cuts Which form. the tongues as above described.

While the wire apertures when used are preferal'ily formed as perforations adjacent the free ends of the tongues. they may he forniotl as slots 22. Iii-3. opening from the edges of the plate ll to free ends of the tongues, o5 shown in .l igg. In this case, the plate may he used a. coral. adjuster, the Wires l)()ll;{"l)fi55t(.ltogether into one slot and engaged by one tongue, looped at 23 and then passed to her into the other slot, as shown in Fig. l. in this oonatruotion the slots should he so formed as to detract as little as po ihle from the rigidity of those wrtions of the plate i l Wil in are adjacent the ends 0% the damping: liflilQ IZQS, since otherwise strain upon. the ooros is apt to warn the piece aml (leer-ease its elli-l'riehcy.

"llihe various forms shown in Figs. 5 to 8 illustrate ihe allagfrtati hi oi the piece to some of its various; utili F. in Fig. 5 iS shaped to the inner certain gener all used. conduit (my. .l'in rs. Figs. o ancl 'l the pieee i 4 ml to well lmown rosettes o't other to than that shown in Fig. 1. While Fig. 8 i a flush receptacle of 1 other forms willrealli 'qgest lllll'llSGlYQS. In all the forms it 1 understood that the threading aperture-s may he omitted., since the essential point is llle tongue "rip. and while it n'light he rlil'licnlt it would still an type. Various "W5; its adaptation to be possible to adjust the wires without the threading apertures adjacent the free ends of the tongues.

I claim as nrvinvention l. A, dcxice of the character described comprisinga substantially flat plate of slightly flexible in.-'ulatin;,r material such as fiber, adapted to loosely lit within the cap of an electrical fitting. said plate being cut to form independent wire passages, the 0pposed edges of each cut so closely approaching" each other as to ctl'ect a gripping action upoxrthc wire in adjusted position under strain conditions.

21A device of the character described crnnprisinp .2 plate of slightly flexible insulatinp; material and a pair of gripping tongues formed in the body thereof, said body having independent apertures formed. therein adjacent the free end of each tongue the purpose described.

A device of the character described, comprising' a plate of slightly flexible insulating .niaterial and a pair ,of oppositely faced gripping tongues formed in the body thcreofi said body having; independent apertures formed therein adjacent the free end of each tongue for the purpose described.

t. A device of the character described,

comprising a plate of insulating material and an insulating tongue formed therein and abutting at its free end a relatively rigid portion of the body of the plate, the

latter being apertured to one side of the free 5. A device of the character described,

compriaiua a plate of slightly flexible insulating material and a'tongnc formed therein and abutting at its free end a relatively rigid portion of the plate, to form a clamp fa an electric conducton said tongue in the :uljustcd position of the device, being flexed from the'plane of the plate and gripping said conductor between the free end of the tongue andthe abutt inn rigid portion of the plate, substantially-as described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

THOMAS J. TOBIN.

Witnesses Gnome A. CAMLION, Jonx EBEL CAMPION.

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