US665322A - Safety device for electric-motor controllers. - Google Patents

Description

Patented Jan. I, IOOI. F. W. GARRETT & G. H. PARMELEE. SAFETY DEVICE FOR ELECTRIC MOTOR CONTROLLERS.

(Application fllad June 16, 1900.)

(No Model.)

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UNITED STATES PATENT @EFIcE.

FRANK IV. GARRETT AND GEORGE H. PARMELEE, OF JOHNSTOYVN, PENNSYL- VANIA, ASSIGNORS TO THE LORAIN STEEL COMPANY, OF PENNSYLVANIA.

SAFETY DEVICE FOR ELECTRIC-MOTOR CUNTROLLERS.

SPECIFICATION forming part of Letters Patent No. 665,322. dated January 1, 1901.

Application filed June 16,1900. Serial No. 20,550. (l lo model.)

To aZZ whom it may concern.-

Be it known that we, FRANK W. GARRETT and GEORGE H. PARMELEE, of Johnstown, in the county of Cambria and State of Pennsylvania, have invented a new and useful Improvement in Safety Devices for Electric- Motor Controllers, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings,

to which form a part of this specification.

Our invention has relation to safety devices for electric-motor controllers, and particularly for that class of controllers which consist of a main moving elementwhich has contacts and connections for connecting two motors both in series and in parallel and having in connection therewith a cut-out switch or a combined reversing and cut-out switch by means of which the direction of movement of the car is controlled and which also operates to cut out of circuit either one of the motors. In controllers of this type as ordinarily constructed when the reversing and cut-out switch has been operated to cut out one of the motors the movement of the main or governing element of the controller to any of its parallel positions will result in more or less confusion of circuits or will cause circuit conditions likely to result in 0 injury to the car apparatus and should be avoided. Ourinvention is therefore designed to provide means of novel and effective character whereby wheii the reversing and cutout switch has been operated to cut out one 5 of the motors the main or governing element of the controller will be automatically locked against movement beyond a certain predetermined safety position; and our invention consists in an electromagneticallyoperated locking device of novel character, together with contacts and connections for controlling automatically the operation of the said device. The contacts and connec tions are also preferably so arranged as to themselves operate as asafety device, whereby if from any cause the locking device is absent or inoperative movement of the main or governing handle beyond the last safety position under the condition above set forth will simply open entirely the motor-circuit.

Our invention also consists in the novel construction, arrangement, and combination of parts, all as hereinafter described, and pointed out in the appended claims, reference being had to the accompanying drawings, forming a part of this specification.

In the drawings, Figure 1 is a develop ment in plane of a controller and connections embodying our invention, and Fig. 21s a detail view illustrating one form of locking 6o device.

The particular controller shown is in general of the type described and claimed in the patents to Frank A. Merrick, Nos. 645,116 and 64:5,117, of March 13, 1900, and now well 65 known commercially as the No. 38 controller. It will therefore be unnecessary to describe in detail the arrangement of confacts and connections or to trace out the circuits in the several normal positions of the controller. Our invention, fi'irthermore, is not limited to this particular controller. The two motors are designated, respectively, as No. 1 and N0. 2.

O is the main moving element or drum of the controller, D the combined reversing and cut-out switch, and R is artificial resistance for connection in circuit in series with the motors in starting them from a position of rest.

c designates the usual contacts on the drum 0, and z the usual contacts of the switch D.

F designates the usual fingers which engage with the contacts 0, and G the usual fingers which cooperate with the contacts .2.

The drum 0 has the several running positions indicated by the broken vertical lines 1 to 7, and the switch D has the seven positions indicated, respectively, as Off, 0 Ahead, Back, No. 1 ahead, No. 1 back, No. :3 ahead, and No. 2 back.

In applying our invention to this controller we place an additional contact 0 on the series side of the drum 0 at the bottom, said contact extending from position No. 1 through position No. 5, and also provide for engagement with this contact an additional finger F 0n the reversing and cut-out switch we offset downwardly portions of the two lower IOO contacts .2 so that they will be engaged, respectively, by the last regular finger G only in the full ahead and back positions, while the offset portion 7; of one contact will be en gaged by an additional finger G in the positions No. 2 back and No. 2 ahead, and the offset portion of the other contact will be engaged by the said finger G in the positions No. 1 back and No. 1 ahead. The two fingers F G we connect by a conductor S. In this conductor S we connect an electromagnet M, whose armature M forms or is made to control the action of a suit-able stop device. In the drawings, Fig. 2, the armature is so arranged that when the magnet M is energized it will be moved to a position where it will engage with the shoulder t of a stopplate T, secured to the shaft of the drum 0 When the latter is moved to a certain predetermined position, which is preferably the position indicated by the vertical line 5. Our invention, however, is not limited to this particular stop device, since we may employ any device in which an armature is made to project or throw a stop into the path of some part which moves with the drum C.

It will be readily seen from the diagram Fig. 1 that when the reversing and cut-out switch is in either its main ahead or main back position (that is, with both motors in circuit) the circuit is open at the finger G and the magnet M is therefore dead. As soon, however, as the said switch is moved to any of its one-motor positions there is in all positions of the drum C from position No. l to and including position No. 5 a direct con nection from trolley from the finger F through the conductor S, magnet M, finger G and contact .e" or .2 into the reversing-switch, thereby energizing the said magnet. The armature M being attracted provides a stop, which effectually prevents the drum 0 from being turned beyond position No. 5. If for any reason the lock should fail to operate, movement of the drum 0 to aposition beyond position No. 5 would simply open the circuit entirely, (by the disengagement of the finger F with the contact portion c,) and the only effect would be, with the contact arrangement shown, the slowing down or complete stoppage of the motors, the latter occurring only in case the motor-man should neglect, when he perceives the speed of the car to be slacking, to return the drum 0 to off position and then again forward onto one of the series positions.

In order to apply our invention to any con troller or" the general type described, it is simply necessary to so modify the arrange ment of contacts as to provide a conductor which carries current only when one or the other of the motors is cut out of circuit and to include in said conductor a magnet for controlling a stop. Vie do not therefore limit ourselves to the specific construction, ar-

rangement, and combination of parts which we have herein shown and described.

Having thus described our invention, what we claim, and desire to secure by Letters Patent, is

l. In a controller for electric motors, the combination with a regulating-switch, having contacts for connecting two motors both in series and in parallel, and a second. switch adapted to out either of said motors out of circuit, of a normally inactive stop for the regulating-switch, and means controlled by the combined operation of both switches for moving said stop to an operative position under certain predetermined conditions.

2. in a controller, the combination with a regulating-switch, having contacts for oonnecting two motors in series and in parallel, and a combined reversing and cut-out switch for said motors arranged to cut out either motor, of a normally inactive stop for limiting the movement of said regulating-switch, and means controlled by the combined operation of both switches for moving said stop to an operative position.

3. In a controller, the combination with a regulating-switch having contacts for conneeting two electric motors in series and in parallel, and a second switch adapted to remove either motor from circuit, of an electromagnetically-controlled stop for limiting the movementof the regulating-switch, and means whereby said stop is inoperative except the second switch be first actuated to remove one of the motors from circuit.

4:. In a controller, the combination with a regulating-switch having contacts arranged to connect two motors in series and in parallel, and a second switch adapted to remove either of the motors from circuit, of an elec' tromagnetically-aetuated stop for said regulating-switch, said switch having contacts arranged to control the actuation of said stop.

5. In a controller, the combination with a regulating-switch having contacts arranged to connect two motors in series and in parallel, and a second switch adapted to remove either of the motors from circuit, of an electromagnetically-actuated stop for said regulating-switch, said switch having contacts arranged to control the actuation of said stop and whereby the latter is inoperative except the second switch be first operated to remove one of said motors.

6. In a controller, the combination with a regulating-switch for connecting two electric motors in series and in parallel, and a second switch for removing either one of the two motors from circuit, said switches having correlated contacts whereby when the said second switch is moved to a position to cut out either of the two motors, movement of the regulating-switch beyond a certain predetermined point will open the motor-oircuit.

IIO

In testimony whereof We have affixed our signatures in presence of two witnesses.

FRANK WV. GARRETT. GEO. H. PARMELEE.

Witnesses:

BLANCHE SMITH, H. W. SMITH.

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