Robinson v. Thresher

28 App. D.C. 22, 1906 U.S. App. LEXIS 5213
CourtDistrict of Columbia Court of Appeals
DecidedJune 5, 1906
DocketNo. 357
StatusPublished
Cited by3 cases

This text of 28 App. D.C. 22 (Robinson v. Thresher) 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
Robinson v. Thresher, 28 App. D.C. 22, 1906 U.S. App. LEXIS 5213 (D.C. 1906).

Opinion

Mr. Chief Justice Shepard

delivered the opinion of the Court:

This is an appeal from the decision of the Commissioner of Patents in an interference declared between an application for patent for an improvement in electric motors and brakes, filed by Edward W. Kobinson April 22, 1904, and a patent issued to Alfred A. Thresher August 18, 1908, on an application filed June 1Y, 1903.

The issue is in eight counts, as follows:

“1. The combination with an electric motor, its shaft and inclosing casing embodying heads having bearings for the shaft, of a brake wheel on the shaft between the heads, a surface with which said wheel co-operates, a spring for effecting engagement between the wheel and its co-operating surface, and an electromagnet for holding the same out of such engagement against the tension of the spring.
“2. The combination with an electric motor, its shaft and in-[24]*24dosing casing embodying beads having bearings for the shaft, of a brake wheel longitudinally movable on the shaft between the heads, a fixed friction surface with which said wheel cooperates, a spring for moving the wheel longitudinally of the shaft and into contact with its co-operating fixed friction surface, and an electro-magnet for holding the wheel-out of engagement with said co-operating surface.
“3. The combination with an electric motor, its shaft, armature, and inclosing casing embodying heads having bearings for the shaft, of a magnetically released friction brake for the shaft located between the armature and one of the heads of the casing.
“4. The combination with an electric motor, its shaft, armature, and inclosing casing embodying heads having bearings for the shaft, of a magnetically released friction brake for the shaft, located between the armature and one of the heads of the casing, and an electro-magnet for releasing the brake located on the head and controlled from the motor-actuating circuit.
“5. The combination with an electric motor, its shaft, armature, and inclosing casing embodying heads having bearings for the shaft, of a friction brake wheel mounted to move longitudinally of the shaft and between the armature and head of the casing, a fixed friction surface with which the wheel cooperates, a clamping disc between the wheel and head, springs acting on the disc to move the wheel into engagement with its co-operating fixed friction surface, and an electro-magnet in the head for moving the disc against the tension of its springs to release the wheel.
“6. The combination with an electric motor, its shaft, armature, and casing embodying heads having bearings for the shaft, of .a magnetically controlled friction brake for the shaft located between the armature and one of the heads, and an electromagnet for controlling said brake having its coil recessed into the inner face of the head.
“7. The combination with an electric motor, its shaft, armature, and casing embodying heads having bearings for a shaft, of 'a magnetically controlled friction brake wheel on the shaft between the armature and one head, a relatively fixed ring on the inner side of said wheel, and means for securing the ring and [25]*25bead together whereby the head and' friction brake may be removed as a body.
“8. The combination with an electric motor, its shaft, armature, and casing embodying heads having bearings for the shaft, of a friction ring between the head and casing, a brake wheel movable longitudinally of the shaft between the head and ring, springs for moving the wheel into engagement with the ring, and electro-magnet for moving the wheel in the opposite direction, and means for securing the ring and head together.”

As said by the Examiners-in-Cliief, who reversed the decision of the Examiner of Interferences in favor of Thresher: “Generally stated, the invention of the issue is a machine comprising (1) an electric motor having an inclosing easing including heads having bearings for its shaft, and (2) a magnetically controlled brake inside of the casing of the motor, and between one of the heads of the casing and the armature of the motor.”

The brake is applied by the tension of springs when unrestrained by the electro-magnet, which is energized by the current that operates the motor. When the current is on, the magnet counteracts this tension, thereby releasing the brake and holding it away from the armature of the motor. When it is cut off, the magnet ceases to restrain the pressure of the springs, which at once apply the brake and stop the revolution of the motor shaft.

The invention is a narrow one, for, as said by the Commissioner: “It appears from the record of this case that devices having these characteristics and functions were known and used before the invention in issue was conceived by either party. The invention is therefore restricted to certain novel details of construction set forth in the various counts of the issue, of which details the most important seems to be the location of the brake within the casing of the motor, or, as expressed in the issue, “upon the motor shaft and between the heads of the motor casing, in which heads said shaft is journaled.”

All of the tribunals of the Patent Office, agreeing that "Robinson labored under the burden always imposed upon one who seeks to overcome a patent held by his opponent, concurred in finding that he had conceived the invention in issue and dis[26]*26closed it to others prior to the date of disclosure claimed by Thresher. Thresher does not claim to have reduced the invention to practice until September 20, 1902. Consequently the question of priority was made to turn upon the sufficiency of Nobin son’s evidence tending to show reduction to practice in June, 1902. On this issue the tribunals failed to agree. The Examiner of Interferences decided against Robinson. His decision was reversed by the Examiners-in-Chief, who heard the appeal therefrom; and they, in turn, were reversed by the Commissioner, who awarded priority to Thresher. 'From this final decision Robinson has appealed.

It appears that both inventors had specially in view supplying the demand of the United States for electric motors to be used for hoisting purposes upon war ships. The object was a motor so designed that the brake would be released as soon as the current was turned on, and act automatically as soon as shut off. The special importance of locating the brake inside the motor casing is to lessen the danger of injury, and the liability to damage from moisture.

Robinson was an electrical designing engineer in the service of the General Electric Company of Schenectady, New York, which has the benefit of his invention. Thresher is engaged in the manufacture of machinery at Dayton, Ohio, under the firm name of the Thresher Electric Company. Both are bidders for government orders. It appears that Robinson filed an application on April 3, 1903, for a patent for a brake device similar to that in issue, but no reference was made therein to an electric motor, nor was one shown either in drawings or specifications. After the issue of Thresher’s patent, Robinson appears to have made several of the claims therein by amendment on September 12, 1903. An interference was declared therein between him and Thresher on October 23, 1903. This was dissolved by the Primary Examiner on March 14, 1904, on Thresher’s motion.

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Bluebook (online)
28 App. D.C. 22, 1906 U.S. App. LEXIS 5213, Counsel Stack Legal Research, https://law.counselstack.com/opinion/robinson-v-thresher-dc-1906.