US1268315A - Insulator-thimble. - Google Patents

Description

R. A. BECKER L T. E. MADDEX.

INSULATOR THIIYIBLE.

APPLICATION FILED JUNE 6.19I1.

l ,268,3 l 5 l Patented June 4, 1918.

I IIl RAYMOND A'. BECKERAND'THOMAS E. MADDEX,'F"HILLSBORO, ILLINOIS.

INSULATOR-THIMBLE.

l Specification of Letters Patent.

Patented J une 4, 1918.

Application ined June 6, 19-17. serial' No. 173,162.

To all whom z5 may concern:

Be it known that we, RAYMOND A. BECKER and THOMAS E. MADDEX, citizens of the UnitedStates, and residents of Hillsboro, iny the lcounty of Montgomery and State of Illinois, have inventedcertain new and useful Improvements' in Insulator-Thimbles, of which the following is a specification.

The present invention relates to insula-y tors, andmore particularly to that type of insulatoradaptedl to be supportedv uponA pins or stud'susually carried upon cross-arms and the like, for supporting' and insulating line wires of high and low tension. d

In priorV insulator construction, wooden pins have been employed which arescrewed directly into the insulator body. Thechief objectionV found to such a construction has been that in the larger size insulators', such asl are used in high-tension transmission,

wood pins are unsuitable on account: of mechanical'weak-ness. This has been attempted tobe overcome by'theprovision of 'metallic pins of sufficient strength but they are found unsatisfactory' on account of the' tendency to cramp the threads and thus'l injure lthe body of the insulator. Ithas also beenk attempted to overcome the defect by the provision of a metal pin which is cemented directly into the insulator pin hole. This, however, has the disadvantagey thatA in installing, thel combined weightof the assem bled pin and insulator body is too heavyto V'be' conveniently handled in Xing the pin or stud tothe cross-arm or other support employed. Further, objection is also found in this latter type of insulator mounting for thel reason that the cement, which is' practically unyielding, transmits or communicates to the rwalls of theinsulator body all of the mechanical stressesset up by the eXpansion and contraction of the metal pin.

Various other attempts have beenmade to overcome all of,V these objections, and a further attempt has been embodied in providing a metal thimble which is internally threaded for detachable'engageinent with a metallicpin or stud, the thimble being cemented into the openingr in the insulator body. Itis readily seen vthat' while thisv latter construction admits of the separate mounting of the pin upon ,theV cross-arm' or other support, does not offset the transmission"'or communication of1 mechanical stresses set up by the expansion and contractionof the metal pin and the thimble to the adjacent walls of the insulator body, thus cracking and breaking the latter. There is one 'instance familiar to the present inventors which embodies the threading of the pin, the threading 4of a shell over the pin which is made of relatively thin metal, and which has the threads thereof pressed into thebody of the shell, and which is cemented inl the insulator body. The closed end of the fshell is provided with a cork inn sertfadapted to cushion .and take up eXpansion' and contraction of the pin, longitudinally. However, the transverse or diametrical expansion and contraction of the pin is not provided for, and such resultant stresses of the thimble causes the cracking and breaking of ythelinsulator body. e

It is the object of the present invention to overcome all of thesedefects by providing a novel form of thimble capable of taking up not only the longitudinal mechanical stresses incident to the lexpansion Iand contraction of the pin andthe thimble, but also the lat-eral or' transverse mechanical stresses, and to provide athimble which may be easily re-V moved and rreplaced upon the stud end of the pin, and'which may be cemented securely in the insulator body.

The above, yand'various other objects and advantages of'this invention will be in part described, and in part understood, from the following detailed, description of the present preferred embodiment, the same being illustrated in the accompanying drawing, wherein:

Figure l is a longitudinal section through an. insulator provided with a thimble constructed according to the present invention, the thimble being shown in elevation.

Fig. 2 is a longitudinal view, enlarged.l of th'ethimble.l disclosed partly in section, and partly in elevation.

Fig. 3 'is a transverse section taken substantially on the line 3-3 of Fig. 2, through the insulator thimble, showing the spacing between the inner and outer sections thereof.

' Referringto this drawing, 10 designates the body of an insulator which may be formed of a plurality of sections in the usual manner secured together in interfitting relation by films of cement 11, or the like.

In the 'present embodiment, the thimble comprises an inner tubular section 12 of metal, or the like, provided with internal screw-threads adapted to receive a supporting pin therein, and admitting of the removal and positioning of the thimble upon the pin by merely screwinor and unscrewing' the thimble with respect tliereto. The base or lower end of the inner section 12 of the thimble is provided with an annular out-- standing flange lhaving a relatively flat lower end or base portion adapted to bind against the pin-and thus securely hold the thimble from turning upon the pin when the thimble is secured in position. The opposite end of the thimble section l2 is provided with a closure wall 14 vwhich may engage the upper end of the supporting pin or arm.

The thimble is provided with an outer or shell section 15 preferably formed from sheet metal and tubular in shape. The outer section 15 is adapted to fit loosely over the inner section 12 and preferably forms an annular space between the two sections, as shown in Fig. 3. This annular space provides for the transverse expansion and contraction of the inner thimble section 12, and the outer shell section 15 is preferably of slightly greater length than the inner section 12 to provide a space vbetween the closure wall 14 of the inner section and the upper closed section 16 ofV the outer section. y

The outer shell section 15 is preferably corrugated annularly to provide peripheral beads and depressions or grooves arranged alternately from end to end of the shell section 15 for the purpose of absorbing longitudinal and transverse mechanical stresses incident to expansion and contraction of the parts. and also to aord anchoring means adapted to be embedded in the cement 17,

or other securing body, adapted to hold the thimble in the opening of the insulator body 10. Y

The open or base end of the shell section 15 is formed into a iiaring flange 18 which is spun or otherwise suitably formedabout the marginal edgev of the base flange 13 of the inner section 12. for the purpose of firmly uniting the sections 12 and 15 of the thimble. It will be noted that the marginal edge of the flange 18 of the outer section 15 .is turned inwardly beneath the base portion of the iiange 13 so as to firmly hold the shell section 15 from longitudinal .displacement from the inner section 12.

It will be noted that the thimble of this invention comprises inner and outer sections which are spaced apart annularly and longitudinally so that the sections are arranged substantially concentric with respect to each other and the said sections are permitted to expand and contract independently of each other without communithe outer shellv 15 may be formed from sheet` metal, or the like, such as drawn steel, and that the parts are firmly united by spinning or overturning the free end iiange of the outer shell about the base flange of the inner section.

K It is of course understood that various changes and modications may be made in the details of construction and design of the above specifically described embodiment of this invention, without departing from the spirit thereof, and being restricted only by the scope of the following claims.

We claim:

1. In an insulator thimble, the combination of an inner cylindrical section having internal threads and an outstanding base ange, and an outer shell section of greater internal diameter than the external diameter of the inner section and provided with a base flange engaging about the base flange of the inner section to hold the sections in concentric spaced-apart relation, said outer section being provided with annular corrugations and being of greater length than the inner section.

2. In an insulator thimble, the combination of an inner section of cylindrical form closed at one end and provided with a base ange at its opposite end, said inner section having internal threads adapted to detachably engage a supporting pin, and an outer section of tubular form tting over the inner section and provided with a closedA end and an outwardly flaring flange vat its opposite end adapted to be turned over the base flange of the inner section for uniting said inner and outer sections, the outer section being also provided with annular corrugations extending from end to end of the outer section to provide peripheral beads adapted to be secured in the opening of an insulator body, and adapted to absorb mechanical stresses transmitted to the thimble.

grooves extending from end to end of the Inodate the longitudinal expansion and conouter section, and adapted to absorb Inetraction of the sections, and Said sections chanical stresses incident to the contraction being provided at their opposite ends with 10 and expansion of the inner section and supinterlocking base flanges adapted to unite 5 porting pin, Said sections being closed at one the same.

end and the outer section being of greater RAYMOND A. BECKER. length than the inner section to accom- THOMAS E. MADDEX.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

f Washington, I). C.

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