US1961402A - Insulator - Google Patents

Description

J. J. TAYLOR June 5, 1934.

INSULATOR Filed Feb. 17, 1933 Fig.1

Patented June 5, 1934 INSULA'IOR John J. Taylor, Barberton, Ohio, assignor to The Ohio Brass Company, Mansfield, Ohio, a corporation of New Jersey Application February 17, 1933, Serial No. 657,202

'7 Claims.

This invention relates to insulators and particularly to insulators subjected to bending moments, such those used for supporting catenary messengers which carry trolley wires and commonly referred to as catenary insulators. The invention is also adapted to a wide range of uses and is applicable to insulators subjected to tension, compression or bending moments.

One object of the invention is to provide an insulator which is adapted to withstand bending moments, although it may be relatively short in the direction of its axis so as to permit a plurality of units to be connected together to provide insulators of varying lengths.

Another object of the invention is to provide an insulator which is adapted to withstand either tension or compression and also bending moments.

Another object of the invention is to provide an insulator of improved construction and operation.

Other objects and advantages will appear from the following description.

The invention is exemplified by the combination and arrangement of parts shown in the accompanying drawing and described in the following specification, and it is more particularly pointed out in the appended claims.

In the drawing:

Fig. 1 is a fragmentary elevation with parts in section showing one embodiment of the invention.

Fig. 2 is a fragmentary sectional view showing a modified form of the invention.

Insulators as heretofore manufactured, and particularly insulators of the flat disc type, have been designed to withstand either tension or compression but the individual units have not been adapted to withstand both tension and compression nor to withstand bending moments. The present invention provides an insulator unit, which although of comparatively short di mensions in the direction of its axis, will withstand both tension and compression and also bending moments, and the units are adapted to be connected together so that a stack of any desired length in th direction of its axis may be built up. An insulator of this kind is particularly well adapted for the suspension of catenary messengers for suppor ing trolley wires, but there are of course many other purposes to which the insulator may be putv In the form of the invention shown in Fig. 1, the numeral 16 designates an insulating disc of porcelain or other suitable material provided with an attachment head having a recess in which a metal pin 14 is secured by cement 15. A cap 16 is secured to the outer surface of the attachment head by cement 17; the surface of the dielectric member being suit- 69 ably roughened to provide a cementing surface 18. A cushion or gasket 19 may be in sorted between the rim of the cap 16 and the disc 10 to prevent the cap from bearing directly on the porcelain at this point. The cap 16 is provided with two tapered bearing surfaces 29 21, inclined in opposite directions relative to the axis of the insulator. The inner surface of the cap is preferably coated with wax, bitumen or other suitable material to pre vent the cement from bonding to the surface of the cap. The pin 14 is also provided with tapered bearing surfaces 22 and 23; the bearing surface 22 being disposed in opposition to the bearing surface 20, and the bearing surface 23 being opposed to the bearing surface 21.

The bearing surfaces of the cap and pin are disposed in symmetrical relation to a plane perpendicular to the axis of the insulator and passing through the apex of the angle formed by the surfaces 20 and 21.

When the insulator is placed under compression, the cement and dielectric material between the surfaces 21 and 23 will receive the load on the insulator and the force of the load will be transmitted between these two surfaces in a direction approximately normal to the bearing surfaces. If the insulator is placed under tension, the load will be received by the bearing surfaces 20 and 22 and transmitted by compression in the dielectric member substantially normal to these two surfaces.

If the insulator is subjected to a bending moment, the insulator at one side of the axis will be subjected to tension and the other side will be subjected to compression, so that one set of bearing surfaces will receive the load at one side of the insulator and the other set of bearing surfaces will receive the load at the opposite side of the insulator. t is thus seen that irrespective of the nature of the load placed on the insulator, opposed bearing surfaces are provided for receiving the force of the load and transmitting the load by compression in the dielectric member. Since the dielectric member has its greatest strength in compression, this strength will be utilized to the best advantage for any form of load to which the insulator is subjected.

In order to prevent concentration of the load over the bearing surfaces 22 and 23, these surfaces may be covered by a suitable resilient means for distributing the load. In l of the drawing, a helical spring 24, wound in successive convolutions upon the bearing surfaces, is shown for this purpose.

The pin 14 is made comparatively large in diameter so as to provide a comparatively long radius from the axis of the pin to the bearing surfaces 23 and 24, since this radius const. utes the lever arm for the bearing surfaces for resisting the bending moment upon the insulator. The increased diameter of the pin also proportionally increases the amount of bearing suri'ace for a given length of pin. It will be noted that the insulator units are made coi'nparatively so that their dimension is relatively short in the direction of the axis, and the units are equipped with stud bolts 25 by which they may be assenwbled to form a stack of any desired length. Since the units themselves are comparatively short in the direction of their axis, the length of the stack may be accurately adjusted to suit any conditions which may arise.

In the form of the invention shown in Fig. 2, the cap 26 is provided with an inwar'ly projecting rib 2'7 which forms supplemental hear ing faces 28 and 29. The bearing face 28 .vill supplement the bearing face 30, and the hearing face 29 will supplement the hearing face 31. The pin 32 is provided with hearing opposed to the bearing faces 29 and 31, and with bearing faces 34 opposed to the bearing faces 28 and 30. The pin 32 is also provided with radial resilient flanges 35 which provide resilient means for supporting a portion of the load, either in tension or compression, and for thus relieving the pressure upon the bearing faces 3'3 and 3441-.

This is particularly advantageous in the of a bending moment which tends to place the greater stress upon the outermost bearing faces 33 and 34. The resilient flanges by ahsorlt' a a portion of this stress, prevent excessive pressure at the extremities of the pin which othe' wise would tend to produce failure in the diele tric member adjacent these points.

I claim:

1. An insulator comprising a dielectric member having an attachment head provided with a eeess, a pin secured in said recess, a cap surrounding said attachment head and secured thereto, said pin and cap each having a pair oi tapered bearing faces inclined in opposite directions relative to the axis of the pin and disposed in symmetric relation relative to the same plane normal to the axis of the pin. the bearing faces on said pin being opposed to the bearing on said cap respectively.

2. An insulator comprising a dielectric member having an attachment head provided. with a recess, a pin disposed in said recess, a cap surrounding said attacl'nnent head, said. pin and cap each having a pair of tapered bearing surfaces inclined in opposite directions relative to the axis of the pin, cement interposed between said pin and cap ipectively and said dielectric member, the pea: surfaces on said pin and cap being arranad symmetrically relative to the plane normal to the axis of the insulator.

An insulator comprising a dielectric member, a pair of metal fittings attached to said dielectric member and each having a pair of tapered be ing faces inclined in opposite direction ive to a common axis and arranged to said co] anon axis.

4. An insulator comprising a dielectric meinher ha\ an attachment head thereon proa pin secured in said resaid attachment head and d pin and cap each having inclined in opposite direst t0 the oi said insulator a disposed syinin: rically relative to the same no plane normal to said aXi 5. An inst itor oinpl *ing a dielectric disc having an attachment head projecting from one thereof and having a recess entering said cite side of said disc, a pin "is, a cap rrounding said ereto, said pin and cap each having a pair of tapered bearing surfaces inclined in opposite directions relative to the axis of said disc and c; sposed in symmetric relation to the plane normal to said axis.

. An insulator co uprising a dielectric me na pin secured in -ed in opposite directions relthe at of the pin and dispo ed in symmetric relation relative to the sam': one normal s, and a resilient ilar e on Sl pin 1 a1 is for transto said a '1. An insulator comprising a die ec 'ic disc having; an attacnn at head projecting at one side thereof, said disc having a recess therein open at ti side of said disc, a pin disposed iis .l\.l cap surrounding said head, said pin and cap having a plurality oi bearing faces inclined in opposite directions to tie VlS of said disc and disposed L nnioti'ic rel on to the same plane normal to said cement securing said pin and cap to said attachment head, and a resilient flange pin extending substantially normal to and embedded said cement for transng a portion cl. the load on said insulator.

JOHN J. TAYLOR.

, a portion of the load on said insulator.

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