Davis v. Chesapeake & P. Tel. Co.

77 F. 895, 1897 U.S. App. LEXIS 2447
CourtU.S. Circuit Court for the District of Maryland
DecidedJanuary 7, 1897
DocketNo. 229
StatusPublished

This text of 77 F. 895 (Davis v. Chesapeake & P. Tel. Co.) is published on Counsel Stack Legal Research, covering U.S. Circuit Court for the District of Maryland primary law. Counsel Stack provides free access to over 12 million legal documents including statutes, case law, regulations, and constitutions.

Bluebook
Davis v. Chesapeake & P. Tel. Co., 77 F. 895, 1897 U.S. App. LEXIS 2447 (circtdmd 1897).

Opinion

MORRIS, District Judge.

This action at law, of trespass on the case, to recover damages for infringement of patent, was instituted April 10, 1896. The patent in suit is Ko. 223,969, granted January [896]*89627, 1880, to J. Henry O. Watts, for an electrical switch pin. By assignment dated September 6, 1883, Watts assigned all his interest therein to his former partner, the plaintiff.

The specification is as follows. .

“My invention relates to that class of devices in use for closing circuit on telegraphic or telephonic switch boards; and it has for its object to furnish, a device for the purpose named, so constructed as to retain itself securely in the switch board, and be not liable to become displaced from the hole by accidental jars or jolts. Switch-board pins have heretofore generally been furnished with cylindrical tips, cleft longitudinally at right angles, so as to be compressible and bind against the metallic edges of the switch-board holes when thrust therein. As a result, the tips of the pins, when in place, wore tapering, and this taper became permanent as the metal of which the tips were composed gradually lost its resiliency from constant or intermittent use. In any case, even when the pins were new, the resultant of the thrusts against the edges of the switch-board holes was outward from the board, so that the security of the pins was represented by the difference between this force and the coefficient of friction, and the pins were liable to fall out of the holes. I obviate this tendency by so constructing the pins that they tend to press into the holes, instead of outward; and the result of jars or jolts to the switchboard is to settle the pins, if possible, more firmly in the holes. This I effect by providing the pins with an enlarged resilient tip, whereby the thrust against the edges of the switch hole is such as to tend to draw the pin into the hole, as will readily be understood.
“In the accompanying drawings, A is the connecting wire, and B the aandle of the pin, constructed, by preference, of hard rubber or equivalent insulator, in order to avoid the perception of a shock as one withdraws the pin from the board. A metallic thimble, b, is attached to the handle, B, and is screwed into the part b', which is integral with the tip, e. The connection, A., is led through the central hole of the handle, and its metallic core being laid bare and tied in a knot, a, the parts b, b', are screwed together, compressing the knot against the metallic faces, and insuring electric connection, while incidentally furnishing a neat and secure means of attaching the connection, A, to the pin.

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Bluebook (online)
77 F. 895, 1897 U.S. App. LEXIS 2447, Counsel Stack Legal Research, https://law.counselstack.com/opinion/davis-v-chesapeake-p-tel-co-circtdmd-1897.