US779182A - Combined circuit-breaker and starting-rheostat. - Google Patents

Description

PATENTED JAN. 3, 1905.

R. H. READ. COMBINED CIRCUIT BREAKER AND STARTING RHEOSTAT.

APPLICATION FILED OUT. 28. 1903.

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No. 779,182. PATBNTED JAN. 3, 1905.

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COMBINED CIRCUIT BREAKER AND STARTING RHEOSTAT.

APPLIOATION'PILED 0012s, 1903.

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VATNESSESI UNITED STATES Patented January 3, 1905.

PATENT OFFICE.

ROBERT H. READ, OF SOHENEOTADY, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF- NEVV YORK.

COMBINED CIRCUIT-BREAKER AND STARTING-RHEOSTAT.

SPECIFICATION forming part of Letters Patent No. 779,182, dated January 3, 1905.

Application filed October 28, 1903. Serial No. 178,809.

To all whom it may concern.-

Be it known that 1, ROBERT H. READ, a citizen of the United States, residing at Schenectady, county of Schenectady, State of New 5 York,have invented certain new and useful Improvements in a Combined Circuit-Breaker and Starting-Rheostat, of which the following is a specification.

This invention relates to starting-rheostats I for electric motors. It is customary to provide motor-circuits with an automatic circuitbreaker which opens both on a failure of current and on an overload in order to protect the motor from the injurious effects in the I one case of a sudden rush of current when the circuit is established and, on the other hand, from damage possible when restarting after failure of voltage; but the former evil effect may be produced if the circuit-breaker is closed without first cutting in the resistancecoils. Hence it is Very desirable to provide some means for compelling the resistance to be cut in before the circuit-breaker can be closed.

The object of my invention is to provide a device of the kind which is simple in construction and efficient and reliable in operation.

It consists of a circuit-breaker having a spring-opened bridging-piece or contact-arm 3o automatically retained in the closed position and adapted to be automaticallyreleased both by the no-voltage coil and by the overloadcoil. The operating-handle of the circuitbreaker is pivoted on the same stud as the con- 3 5 tact-arm and is free to turn independently thereof, but can be clutched to it when it is desired to set the circuit-breaker. The clutch can be operated either mechanically or electrically, and in either case it is controlled by the switch-arm of a motor-starting rheostat arranged adjacent to the circuit-breaker, the construction being such that the rheostat-arm will operate the clutch only when said arm is brought to the off position.

In the accompanying drawings, Figure 1 is a front elevation of my combined circuitbreaker and rheostat. Fig. 2 is a top plan view of the same, and Figs. 3 and 4. are respectively similar views of a modification.

The parts are supported on a suitable panel, 5 of slate or other insulation, to which are secured the line- terminals 1 and 1. The circuit-breaker has the usual stationary springmounted contacts 2 and 2*, adapted to be connected by the bridging-piece 3, insulated from 5 5 the contact-arm 4c, pivoted at 5 and urged away from said contacts by the coiled spring 6. A no-voltage coil 7 and an overload-coil 8 are arranged to trip the circuit-breaker detent and permit the spring to throw the contact-arm out of engagement with the contacts 2 and 2 in the usual manner. The details of this mechanism are well understood by those skilled in the art.

"he circuit-breaker-operating handle 9 is 6 pivoted on the same stud as the contact-arm and turns freely thereon independent of said contact-arm. The opposing faces of the hubs of the handle and contact-arm are provided with cooperating clutch-teeth, so that when the hub 9 of the handle is slid axially against the hub of the arm the two will interlock and the arm can be moved by moving the handle. The handle-hub has a circumferential groove 10, with which engages the forked end of an elbow-lever 11, suitably fulcrumed in a standard 12, secured to the panel. A spring 13 causes the lever to keep the clutch normally open, as shown in Figs. 2 and 4c.

The rheostat switch-arm 14: is pivotedat 15 and cooperates with the contact-buttons 16 of the rheostat. l Vhen this arm is moved to the OE position after cutting all the resistance into the armature-circuit of the motor 17, it operates to move the elbow-lever and close the clutch. Two ways of accomplishing this are shown. In Figs. 1 and 2 the switch-arm has a cam 18, which strikes one end of a bent lever 19 and moves it to the left, causing a fork 20 on the other end of the lever, which engages with the short end of the elbow-lever 11, to rock said lever on its fulcrum and throw the handle-hub against the hub of the contactarm.

In Figs. 3 and 4: the switch-arm carries an insulated blade 21, which closes a shunt-circuit containing an electromagnet 22, which when thus energized attracts the free arm of the elbow-lever and closes the clutch. In either case the circuit-breaker cannot be set until the switch-arm 14 is brought to the off position. WVhen the breaker is set, it latches automatically, and the switch-arm can then be swung to the left to cut out the resistance, After the lever 1 is swung from its ofi position the bent lever 19 drops or the magnet 22 is deenergized, allowing the clutch to open. If now the circuit-breaker goes off, it cannot be reset until the switch-arm is moved to the extreme right, which cuts all the resistance into the motor-circuit and then opens said circuit. It is therefore impossible for the attendant to set the breaker while the resistance is cut out. As shown, both the overload-magnet 8 and the no-voltage magnet 7 act on the same arm, the windings being so proportioned that the no-voltage magnet normally overcomes both the retracting-spring and the over load-magnet. Any other arrangement of these magnets by which either may trip the lever 4: under the desired conditions might of course be employed.

What I claim as new, and desire to secure by Letters Patent of the United States, is-

1. The combination, with an automatic circuit-breaker, of a rheostat, means for disconnecting the operating-handle from the movable contact of the circuit-breaker, and means controlled by the rheostat-arm for establishing a connection between the handle and movable contact only in the off position of said arm.

2. The combination with a circuit-breaker, of an automatic starting-rheostat, and means for connecting and disconnecting the handle from the movable contact of the circuitbreaker, said means being controlled by the rheostat-arm.

3. The combination with a circuit-breaker, of a starting-rheostat, a clutch for connecting and disconnecting the handle of the circuitbreaker, and means for operating said clutch controlled by the rheostat-arm.

4c. The combination with a circuit-breaker, of a starting-rheostat, a clutch for connecting and disconnecting the handle of the circuitbreaker, a lever for operating said clutch, and means for actuating said lever controlled by the rheostat-arm.

5. The combination with a circuit-breaker, of a starting-rheostat, a clutch for connecting and disconnecting the handle of the circuitbreaker, an elbow-lever for operating said clutch, a cam on the rheostat-arm, and actuating connections between said cam and the lever.

In witness whereof I have hereunto set my hand this 26th day of October, 1903.

ROBERT H. READ. Witnesses:

BENJAMIN B. HULL, HELEN ORFORD.

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