US1545433A - Electrical apparatus - Google Patents

Description

July 7, 1925.

R. L. LEE ET AL ELECTRICAL APPARATUS Filed Sept. 26. 1923 THEIFJQZZDI'HEQ Patented July 7, 1925.

UNITED STATES PATENT OFFICE.

RALPH L. LEE AND MORTIMER W. FISH, OF DAYTON, OHIO, ASSIQNOBS T0 DELCO- LIGHT COMPANY, OF DAYTON, OHIO, A CORPORATION OF DELAWARE.

ELECTRICAL APPARATUS.

Application filed September 26, 1923. Serial No. 664,828.

To all whom it mag concern:

Be it known that we, RALPH L. LEE and MORTIMER WV. FISH, citizens of the United States of America, residing at Dayton, county of Montgomery, State of Ohio, have invented certain new and useful Improvements in Electrical Apparatus, of which the following is a full, clear, and exact description.

This invention relates to electric motors and apparatus for effecting operation of the motor in either direction and has among its objects the prevention of racing of the motor in either direction of rotation when a load is suddenly removed.

Other and further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings, wherein a preferred embodiment .of one form of the present invention is clearly shown.

In the drawings:

Fig. 1 is a diagrammatic view of a preferred embodiment of one form of the present invention.

Fig. 2 is a diagrammatic view of a modified form of the invention.

In the drawings, a motor armature 20 is provided with a stationary motor brush 21, and movable brushes 22 and 23 mounted on non-conducting arm 24 which is pivoted at 25 and is provided with an operating handle 26. Brushes 22 and 23 are adapted to be alternately moved into and out of engagement with the motor commutator by movement of the operating handle 26. Brushes 22-and 23 are permanently connected with fields 27 and 28 of opposite magnetic effect, said fields being connected with one side of the line by wire 29. Brush 21 is connected with the opposite side of the line by wires 30 and 31. A resistance unit 32 arranged in parallel with motor armature 20, is connected with brush 21 by wires 30 and 33 and is connected with stationary contacts 34 and 35 with which contacts 36 and 37,

carried respectively by brushes 23 and 22, are ada ted respectively to enga e when the ban le 26 is operated alternate y to engage the brushes 22 and 23 with the motor commutator. I I

When the brushes'22 and 23 are in the position shown in Fig. 1, the flow of current will be from the source of current, wire 31, wire 30, brush 21, across armature 20, brush 22, field 27, wire 29, back to the source of current. After the handle 26 is operated 33, resistance 32 to contacts 34, 36, orv 35, 37,

depending upon which brush 22 or 23 is in engagement with the commutator. Under no load, the motor armature 20 will tend to speed up and'as it speeds up, the voltage across the armature .will be greatly increased, thus causing more of the current to fiow through the resistance 32, and cutting down the current flowing through the armature 20. thus tending to reduce the speed thereof. Thus at no load, the resistance 32 will tend to prevent the motor from racing.

In the modified form of the invention shown'in Fig. 2, the resistance 32 is permanently connected in parallel with the motor armature 20, being connected with stationary brush 21 and an auxiliary brush 40 which is always in engagement with the motor commutator.

It will of course be understood that the operating handle 26, may be thrown into a neutral position, whereby both brushes 22 and 23 may be out of engagement with the motor commutator, thus stopping the motor.

While the form of mechanism herein shown and described constitutes a preferred embodiment of one form of invention, it is to be understood that other forms might be adopted and various changes .and alterations made in the shape, size, and proportion of the element therein withoutdeparting from the spirit and scope of the invention.

What is claimed is as follows: v

'1. An electric motor comprising, in combination, a plurality. of field windings, an armature, a commutator, movable brushes each connected with Oneof-said field windings and adapted to be alternately moved into and out of engagement with the commutetor, a stationary brush,-a resistance connected therewith, and means for moving said movable brushes alternately into and out of engagement with the commutator and for alternately connecting said brushes with said resistance whereby the resistance is placed in parallel with the armature. I 1

2; An electric motor comprising, in combination, field windings, a commutator, movable brushes, each connectedvto one of said field windings, a stationary brush, a resistance Winding connected therewith and adapted to be connected with either 'of said movable brushes and means for alternately mov-' ing said movable brushes into engagement with the commutator and connecting the resistance winding in' circuit with the field winding connected with the commutator.

' 3. An electric motor comprising in combination, field circuits each including a movable brush, a commutator, a stationary brush, a resistance winding connected therewith, and means for causing either one of the field circuits tovbe brought into'operation and for connecting the resistance winding in circuit with the field circuit so affected.

- 4. "An electric motor comprising in com bination, field windings, a commutator, movablebrushes each connected to one of said 'field' windings, a stationary brush, a resistance Winding, and means for concurrently,

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