Dunbar v. Schellenger

29 App. D.C. 129
CourtDistrict of Columbia Court of Appeals
DecidedFebruary 5, 1907
DocketNo. 409
StatusPublished

This text of 29 App. D.C. 129 (Dunbar v. Schellenger) is published on Counsel Stack Legal Research, covering District of Columbia Court of Appeals primary law. Counsel Stack provides free access to over 12 million legal documents including statutes, case law, regulations, and constitutions.

Bluebook
Dunbar v. Schellenger, 29 App. D.C. 129 (D.C. 1907).

Opinion

Mr. Chief Justice Shepard

delivered the opinion of the Court:

This is an interference proceeding involving priority of invention of a means for operating the supervisory signals of a telephone system, and was declared between the application of Newton C. Schellenger, filed February 14, 1901, and that of Francis W. Dunbar, filed March 22, 1901.

The issue contains ten counts, as follows:

“1. The combination, with a telephone line, of a source of electricity and a pair of relays adapted to be bridged between the limbs of the talking circuit thereof, a switch at the substation and a switch at the central station for controlling the circuit through said relays, and a signal adapted to be controlled by the conjoint action of said relays.
“2. The combination, with a pair of telephone lines, of an inductive device through which the same are adapted to be united for conversation, a charging source of electricity, and a pair of relays adapted to be bridged between the two limbs of each of said lines, one pair of relays being individual to one of said lines, and the other pair being individual to the other line, switches at the substations and at the central station for controlling the circuit through said relays, and a signal controlled by the conjoint action of each pair of relays.
“3. The combination, with a metallic telephone line free from permanent grounds outside the central office, of a charging current source, a third conductor, a pair of relays at the central office, one of said relays being energized over the telephone line, [132]*132and the other over a portion of the talking circuit and. the third conductor.
“4-. The combination, with a metallic telephone line, of a pair of relays and a charging current source bridged across the line at the central station, a third conductor to' which one pole of the current source is connected, both of said relays being adapted to be operated over the metallic telephone line, and one of said relays being adapted to be operated over a portion of said line and third conductor.
“5. The combination, with a metallic telephone line, of an operator’s plug and a cord circuit, a source of current and a pair of relays bridged across said circuit, a third conductor connected with one pole of said source, one of said relays being adapted to be operated over the metallic line when the subscriber’s telephone is in use, and the other to be operated over a part of the line and said third conductor when the subscriber’s telephone is not in use and the operator’s plug is connected with, the line.
“6. In a telephone system, the combination, with a telephone line, of a source of current and a relay bridged between the two limbs of the talking circuit thereof, a second relay at the central office connected in a circuit including a portion of one side of the talking circuit and means for energizing it, a switch at the substation and a switch at the central station for controlling the circuit through said relays, and a signal controlled by the conjoint action of said relays.
“1. In a telephone system, the combination, with a telephone line, of a source of electricity at the central office, an operator’s plug and a pair of relays associated therewith, one of said relays being energized from the said source of electricity as long as the said operator’s plug is connected with the said line and over a path having a part coincident with the talking circuit, and the other relay being energized as long as the said operator’s plug is connected with the said line and when the subscriber’s telephone is in use, and a signal associated with said pair of relays, the circuit of said signal being established by the operation of [133]*133the first of said relays, and said signal being rendered inoperative by the operation of the second of said relays.
“8. The combination, with telephone lines extending from subscriber’s stations to an exchange, of a cord circuit at the exchange provided with two strands for forming connections between two telephone lines, a pair of relays corresponding to each end of the cord circuit and included in bridge thereof, a source of current for inclusion in circuit with each of said pairs of relays, a supervisory signal for each pair of relays and jointly controlled thereby, switching apparatus for controlling the operation of the relays, and a condenser included in each cord strand between the connections of the relays therewith.
“9. The combination, with telephone lines extending from substations to jacks at an exchange, of a cord circuit at the exchange provided with two strands for forming connections between subscribers’ lines, a pair of relays corresponding to each end of the cord circuit and included in bridge thereof, a source of current for energizing the said relays, a supervisory signal for each pair of relays and jointly controlled thereby, switching mechanism at the substations for controlling the operation of one of each pair of relays, means including a jack and a cord-circuit plug inserted in the jack, whereby a closed circuit is established through the remaining relay of each pair, which is independent of the operative position of the substation apparatus, and a condenser included in each cord strand between the connections of the relays therewith.
“10. In a telephone system, an operator’s cord circuit, a pair of relays each operated over circuits including portions of the talking circuit, and a supervisory signal having its circuit controlled by the contacts of both of said relays, one of said relays being adapted to normally close the circuit and to be energized over the telephone line when the line is in use, whereby the signal is at that time rendered inert, and the other relay being adapted to normally open the circuit, whereby when the cord circuit is not connected with the line the signal is inert, and when connected with a line in use the signal is displayed.”

The Examiner of Interferences held that Dunbar’s evidence [134]*134established September 17, 1900, as the date of conception of the invention of the issue; but, being of the opinion that Schellenger’s clearly showed conception and reduction to practice in August, 1900, priority was awarded to him. lie expressed the opinion, also, that, even were the evidence of reduction to practice insufficient, Schellenger’s diligence nevertheless entitled him to the benefit of his earlier conception.

The decision reviews the testimony at great length, and contains an elaborate description of the invention as disclosed in the applications of the respective parties. This description seems to be an accurate one, but its insertion would occupy unnecessary space.

After noting an appeal from this decision, Dunbar filed a motion to restore jurisdiction to the Examiner of Interferences in order that he might entertain a motion to reopen the case for the introduction of alleged newly discovered evidence. The evidence consisted of the testimony of Schellenger as a witness, on July 5, and 18, 1905, on behalf of Clausen in an interference between Clausen and Dean, No. 23,797, relating to telephone circuits and signals. To the motion were attached a transcript of said testimony, the affidavits of counsel, and the affidavit of an expert relating to the evidence in connection with the issues, and the evidence in the present case.

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29 App. D.C. 129, Counsel Stack Legal Research, https://law.counselstack.com/opinion/dunbar-v-schellenger-dc-1907.