US2703820A - Insulator assembly - Google Patents

Description

March 8, 1955 R. E. LAYMAN INSULATOR ASSEMBLY Filed March 6, 1953 INVENTOR floe/" Z l y United States Patent INSULATOR ASSEMBLY Robert E. Layman, Janesville, Wis. Application March 6, 1953, Serial No. 340,879

1 Claim. (Cl. 174-156) The present invention relates to insulator assemblies and more particularly insulator structures of the type used for outside electrical conductors such as, telephone and telegraph wires, the insulator structure being defined by a body portion and a cap removably secured to the body portion, the body portion and the cap being formed of a plastic material which is substantially unbreakable.

It is, of course, well known that moisture on the wires causes a wet weather cross or a high resistance short between the wires and numerous insulators have been designed to protect the wires from rain, snow and sleet in an attempt to overcome the problem. Many of these prior units have been quite satisfactory but due to the complexity of the modified insulator structure such prior devices have not been fully satisfactory.

Accordingly, an important object of this invention is to provide an insulator assembly which will protect the wire from moisture and at the same time be simple in structural detail, positive and efficient in operation and capable of being easily and inexpensively manufactured.

A further object of my invention is to provide an insulator assembly of the type described wherein the insulator consists of but two parts capable of being readily assembled or disassembled with each part being made of a plastic material whereby the insulator is capable of use over extended periods of time.

And yet a further object of the invention is to provide an insulator wherein the assembly is defined by a body portion carried by the cross-arm pin, a cap secured to the body portion and means to anchor the wire between the body portion and the cap so that the wire pulls against the pin rather than the cap thereby eliminating slipping, bend and breakage of the wire.

Still another object of the invention is to provide an insulator assemblage wherein the cap member so cooperates with the body portion as to permit bending of the wire only in a downward direction thereby preventing breakage of the wire which is caused by the upward and downward bend in very cold weather.

With the above and other objects in view, the invention consists in the details of construction, and in the arrangement and combination of parts to be hereinafter more fully set forth and claimed.

In describing the invention in detail, reference will be had to the accompanying drawings forming part of this application, wherein like reference characters denote corresponding parts in the several views and in which:

Figure 1 is a perspective view of a cross-arm, partly broken away showing the threaded vertical pin.

Figure 2 is a further view in perspective, partly broken away of a cross-arm with the insulator assembly in position on the threaded pin depicting the manner in which the wire enters and leaves the insulator assembly.

Figure 3 is a vertical sectional view of the assembled insulator, the threaded pin of the cross-arm being omitted.

Figure 4 is a view taken along the line 44 of Figure 3, the view looking in the direction of the arrows, and Figure 5 is a view taken along the line 5-5 of Figure 3, the view looking in the direction of the arrows.

As perhaps best illustrated in Figure 3, the insulator assembly denoted generally comprises a body portion 11 and a cap 12. Both the body portion and the cap are made of a substantially unbreakable plastic thereby providing an insulator which may be used for an extended period of time without repair or replacement problems.

The body portion 11 includes a cylindrical base 13 having a longitudinal bore 14 therein, the bore being formed with internal screw threads 15 adapted to engage external threads 16 of a vertical pin 17 carried by a cross-arm 18. Hence, the insulator is easily and readily attached to the cross-arm.

The base 13 is further provided with a horizontally disposed shoulder 19 intermediate the upper and lower ends thereof, the shoulder having two pairs of diametrically opposed grooves 20 therein, the grooves being located adjacent the outer periphery of the shoulder as best depicted in Figure 5. One or more of the said grooves will receive the wire, as will be later more fully described.

The diameter of the base 13 is reduced above the shoulder 19 to define an extension 21 and the extension is externally threaded as shown at 22. The cap 12 is of conical outline and is formed with an internally threaded bore 23 for receiving the threads 22 of the extension 21 to assemble the complete insulator. It will be seen that the lower face of the cap is formed with a planar surface 24 and an outer edge 25, the surface 24 and edge 25 being separated by an annular groove or channel 26.

It will be understood that the wire may be lodged in any one of the grooves 20 and when the cap is drawn up on the extension 21, the wire will pull against the pin instead of the cap. Also, the surface 24 and the edge 25 will prevent any upward bend of the wire thereby permitting only a downward bend. Since the downward and upward bend in extremely cold weather is the motivating factor in causing breakage, it will be appreciated that such breakage is reduced materially, if in fact not eliminated. There is thus provided a lock at each side and a most troublesome problem solved by this arrangement.

It should be mentioned that while I have shown two pairs of grooves 20, a lesser number could be present in the base but I have found that the groove assemblage depicted in Figure 5 is the most desirable for commercial purposes.

From the above description, it is deemed manifest that the present insulator assembly is quite simple in structural detail and allows of the easy and speedy attachment of the wire to the base. That area of the wire in contact with the groove in the base is fully protected from the elements and by virtue of the surfaces at the lower end of the cap, the wire cannot bend or flex upwardly thus eliminating wire breakage.

Manifestly, the insulator assembly is capable of modification in the details of construction and in the arrangement of parts without departure from the principle of construction and mode of operation involved or from the scope of the appended claim.

I claim:

An insulator assembly for use with outside electrical conductors including a cylindrical body portion of plastic material having an internally threaded bore therein for attachment to an externally threaded support, a horizontally disposed planar shoulder on the body portion intermediate the ends of such body portion, the shoulder being provided with two pairs of diametrically opposed grooves therein adjacent to the outer edge of the body portion, each of said grooves being capable of receiving an electrical conductor, an externally threaded extension on the body portion above the shoulder, a conical cap of plastic material having an internally threaded bore for cooperating with the threaded extension to complete the insulator, the diameter of the lower end of the cap being materially greater than the diameter of the body portion, the lower end of the cap being formed with a horizontal planar surface which extends beyond the outer edge of the body portion, and an annular groove in the lower end of the cap intermediate the periphery of the cap and the horizontal planar surface so that when the cap is drawn up on the extension, the said planar surface together with the outer edge of the cap will prevent the upward movement of the conductor in the groove thereby eliminating breakage of the conductor.

(References on following page) 3 4 References Cited in the file of this patent 853,744 Steinberger May 14, 1907 UNITED STATES PATENTS FOREIGN PATENTS 544,778 Sproat et a1. Aug. 20, 1895 34,298 Switzerland June 30, 1905 619,555 Frantz Feb. 14, 1899 5 120,418 Great Britain Nov. 5, 1918 759,276 Hobert May 10, 1904

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