US 1865134 A
Description (OCR text may contain errors)
June 28, 1932.
B. A. PLIMPTON POLE TOP BRACKET Filed March 16, 1928 gmac/nto@ Patented June 28, 1932 o VV Y' UNITED STATES PATENT OFFICE BENTLEY A. PLIMPTON, OF BALTIMORE, MARYLAND, ASSIGNOR TO LOCKE INSULATOR CORPORATION, OF BALTIMORE, MARYLAND, A CORPORATION OF MARYLAND POLE TOP BRACKET Application led March 16, 1928.
This invention relates to supports for insulators of current transmission lines and has special reference to supports of that type used in that character of installation where it is customary to provide a wooden crossarm on a pole and to mount two insulators upon the end portions of such cross-arm, and an additional insulator on the pole itself near the top thereof.
Tt is well known in the art that where use is made of a wooden cross-arm the bolts for holding the pins which support the insulators on the cross-arms are necessarily of considerable length owing to the thickness of the wooden cross-arm, whereas the bolt provided for securing the insulator supporting pin upon the metal bracket commonly used at the top of the pole is quite short. The result is that the manufacturer must carry and the customer use two types of pins or pins having bolts of different lengths, thus at least prac tically doubling the amount of stock to be kept on hand, with the attendant inevitable disadvantages when handling different styles or sizes of articles.
It is with the above facts in View that T have designed a pole top bracket of such con struction as to take the same length of bolt as is provided for the pins mounted on the crossarm, thereby making it necessary to make and use only one size instead of two, resulting in a decrease in the cost of production and increase in the ease of installation.
An important object is to provide a pole top bracket which does not in any way require the use of a special bolt or pin, exactly the same ones used on the wooden crossearm being engageable upon this bracket.
A further object of the invention is t0I provide a bracket of this character which is preferably formed from a single piece of material capable of being stamped to shape and which will consequently be extremely cheap and easy to manufacture as well as easy to apply in addition to being efficient and durable in service.
To the attainment of the foregoing and other objects and advantages, the invention preferably consists in the details of construe* tion and the arrangement and combination of Serial No. 262,205.
parts to .be hereinafter more fully described and claimed, and illustrated in the accompanying drawing in which:
Figure 1 is an elevation of a supporting pole and wooden cross-arm thereon and illustrating a pair .of insulators mounted upon the cross-arm and a third insulator mounted upon the bracket constituting the subject matter of the invention, and
Figure 2 is a perspective view of the bracket alone.
Referring more particularlyto the drawing, the numeral 1() designates a pole of ordinary type on which is mounted a wooden cross-arm 11 preferably strengthened'by the inclined braces 12 in addition to being held by the bolt 13. The cross-arm is located at a position spaced somewhat downwardly from the top of the pole so that the latter will project upwardly so as to be capable of supporting an insulator in a higher position. This is an extremely common type of installa tion. Itis customary to mount upon the end portions of the cross-arm insulators 14 and to mount a similar one at the top of the pole, the insulators being carried by pins 15 from which project bolts 16 which pass through tle cross-arm and which carry securing nuts 1 As stated above it is customary to provide a metal bracket at the top of the pole, which metal bracket requires a much shorter bolt for mounting the insulator pin than the bolts shown at 16. However, in the present instance, I have shown the usual type of pole bracket as replaced by the bracket indicated generally at 18. This bracket is preferably formed from a single piece of metal and might of course be a casting though it is probably advisable to form it of bendable iron so that it may be cut and stamped into the desired shape. This bracket 18 includes a main elongated plate-likebody portion 19 which has its upper end bent or otherwise formed to extend at right angles for providlator pin at the top of the pole. Intermediate its ends the plate portion 19 is provided with a laterally extending lug 21 here disclosed as struck-out from the plate portion,
lng a shelf 20 serving as a seat for the insu! lll the latter being initially out along parallel longitudinal lines 22 and a transverse line 23 so that the material lying between these lines may be forced out to extend right angularly as shown. The shelf 20 and lug 21 are formed with alining holes 24 and 25, respectively, which may be drilled or otherwise formed, and which are for the passage of the pin 16. The intention is that the distance between the top surface of the shelf 20 and the bottom surface of the lug 21 be substantially the same as the thickness or height of the cross-arm 11 so that the same length of bolt will be used for mounting the pin either upon the bracket or upon the cross-arm. I preferably provide a sleeve 26 surrounding the bolt and extending between the shelf 20 and the lug 21 for the purpose of preventing drawing them together when the nut 17 is tightened. Actually the sleeve consists simply of a length of ordinary pipe.
It is immaterial whether the bracket have its plate or attaching portion 19 flat, as shown, or concavo-conveX in cross section to conform more or less to the curvature of the pole, as this is a mere detail of design. In either event the plate portion is formed with any suitable number` of holes 27 for the passage of bolts or lag screws 2S whereby the bracket may be mounted upon the pole.
From the foregoing description and a study of the drawing it will be apparent that I have thus provided a pole top bracket capable of taking the same pin and bolt used for mounting the insulators upon the ordinary wooden cross-arm, there being no necessity for making or carrying two sizes of bolts. Inasmuch as the pins and bolts are rigidly connected when manufactured, the necessity for having bolts of different lengths requires having two sets of pins and all this is avoided by the use of my bracket.
It is believed that the construction, operation and advantages will be readily apparent to one skilled in the art without further explanation.
While I have shown and described the preferred embodiment of the invention, it should be understood that the disclosure is merely an exempliflcation of the principles involved as the right is reserved to make all such changes in the details of construction as will widen the ield of utility and increase the adaptability of the device provided such changes constitute no departure from the spirit of the invention or the scope of the claim hereunto appended.
Having thus described the invention, I claim:
A pole top bracket for supporting an insulator carried by a pin from which depends a bolt equipped with a nut, said bracket comprising a metallic member having its upper end formed with a lateral extension constituting a shelf and having its intermediate