Publication: Electrical Review
New York, NY, United States
A New Duplex Pin Insulator.
Mr. R. G. Brown, of New York, has designed a new duplex pin and bracket, illustrated on this page, which the The E. S. Greeley & Co. are manufacturing.
In the drawings Fig. 1 is an oak pin made longer than usual, so as to project some inches through the cross-arm. A thread is cut on both ends, so that an ordinary pony or other glass insulator can be screwed on the top, and a new glass insulator of Mr. Brown's design screwed on the lower end, as is clearly shown. The lower insulator has an opening which extends centrally through it from top to bottom. The wall of this opening is screw-threaded throughout its length. When this insulator is screwed upon the downwardly projecting pin, which is to sustain it upon the cross-arm, any moisture, as from rain, which may fall upon the rounded or convex top will readily flow off, and in event of any moisture finding entrance into the opening about the pin, its tendency will be to pass downward and flow out or escape through the bottom of the opening. Fig. 2 is an illustration of a six-wire line, such as is often seen in the country. One pole shows the present system of cross-arms, pins and brackets, and the remaining pole shows the new system as intended by Mr. Brown. The wires on both poles are held at exactly the same distance apart, and the under insulator and its wire are some inches away from the cross-arm. Consequently the objections pointed out as existing in the present system, whereby the wires are liable to become crossed and the defective insulation caused by insects, nests, etc., are impossible under the new plan.
The new system is specially adapted to the building of telephone lines, both for pole and housetop work.
As there are but one half the number of cross-arms, pins, and bolts required, the cost in construction is less and the line presents a lighter, neater and less objectionable appearance in the eyes of the public.