Telegraph and telephone wire
US 290769 A
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Description (OCR text may contain errors)
TELEGRAPH AND TELEPHONE WIEE.
No. 290,769. I Patented Dec. 25, 1883.
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GORHAMI GRAY, OF BOSTON, MASSACHUSETTS.
TELEGRAPH AND TELEPHONE WIRE.
To all whom it may concern.-
Be it known that I, GORHAM GRAY, of Boston, in the county of Suffolk and State of Massachusetts, have invented certain new and use ful Improvements in Telegraph and Telephone fires; and I do hereby declarethat the followingis a full, clear, and exact description of the invention, which will enable others skilled in the art to which it appertains to make and use the same, reference being had tothe accompanying drawings, which form a part of this specification.
My invention has relation to wires for telegraph and telephone lines; and it consists in an anti-inductive wire, as hereinafter more fully described and claimed.
In telephone-wires as now ordinarily constructed, great difficulty is experienced, especially on long lines, in carrying on plain and intelligible conversation between two points connectedby the wire, on account of induction from other wires in proximity to the telephonewire; and my improvement consists in an insulated wire of the form described and claimed, whereby I have found, by practical experiment over long lines and amidst a system of other wires, that the induction is greatly lessened, and the conversation carried on between the two points at the opposite ends of the wire EOIFICATION forming part of Letters Patent No. 290,769, dated December 25, 1883,
Application filed January 3, 1883.
made very much plainerand more intelligible, owing to the anti-inductive properties of my improved wire.
In the accompanying drawings, Figure 1 represents a perspective view of a piece of my improved wire, and Fig. 2 is a cross-section on an enlarged scale of the same, like letters of reference indicating corresponding parts in both the figures.
By reference to these figures it will be seen that I form my improved anti-inductive wire with a series of spiral grooves, B, formed by indenting the metal of the wire body A. The special machinery wherebythese spiral grooves are formed forms the subject of another application for Letters Patent.
I claim as my invention and desire to secure by Letters Patent of the United States An anti-inductive device for telegraph and telephone lines, consisting ofa spirallygrooved wire, substantially as set forth.
In testimony that I claim the foregoing as my own I have hereunto affixed my signature in presence of two witnesses.
ALVAH L. Swnrr, J. F. REILY.