UNITED STATES PATENT OFFICE
SAMUEL OAKMAN, OF MELROSE,
MASSACHUSETTS, ASSIGNOR TO THE
AMERICAN INSULATOR COMPANY, OF NEW YORK.
SPECIFICATION forming part of Letters Patent No. 288,360, dated November 13, 1883
Application filed July 30, 1883. (No model.)
To all whom it may concern:
Be it known that I, SAMUEL OAKMAN, of Melrose, in the county of Middlesex and State of Massachusetts, have invented certain new and useful Improvements in Telegraph-Insulators, of which the following is a specification.
My invention relates to that class of glass insulators which are supported upon screw-pegs, and has for its object to so construct the interior of the insulator that it shall have a broad interior band of weather-protected surface for insulation between the exterior of the insulator and the supporting-peg; also, in providing the interior of the insulator with an annular recess for the reception of paraffine or some similar moisture repellent. These objects I attain by the mechanism illustrated in the accompanying drawings, in which -
Figure 1 is an elevation of one of my insulators, and Fig. 2 is a cross-vertical section of the same.
In the drawings, A B C represent the body of the insulator. This insulator has a screw thread, D, formed on its interior, as shown in Fig. 2, of the ordinary style and dimensions of the standard insulators now in general use. I also form on the interior surface an annular recess, C', which serves to receive a coating or body of paraffine or other moisture repellent. Immediately below the recess C' I form the annular shield E and the upwardly projecting recess H.
By the above-described construction I attain, in connection with the internal screw, D, an interior insulating-surface, 1 2 3 4 5 6, Fig. 2, a part of which - viz., the part 2 3 - is especially adapted to receive and retain paraffine. Another part - viz.,the part 3 4 - is doubly protected from the weather; and a third part, 4 5 6. adds to the interior insulating-surface.
The arrangement of the interior of a screw insulator, as above described, gives a great advantage over the ones now in use. By it I am enabled to obtain in a single moderate sized insulator all of the advantages of the different styles heretofore in use.
Having thus described my invention, what I desire to secure by Letters Patent is -
1. A glass insulator having formed within j its interior a screw-thread. D, recess C', shield E, and recess H, all substantially as described, and for the purpose set forth.
2. A glass insulator, having formed within its interior a screw-thread, D, shield E; and recess H, in combination with the screw-peg P, all substantially as described, and for the purpose set forth.
FRANK G. PARKER,