US1557080A

US1557080A - Short-circuiting device

Info

Publication number: US1557080A
Application number: US562077A
Authority: US
Inventors: Henry D Murdock
Original assignee: Westinghouse Electric and Manufacturing Co
Current assignee: CBS Corp
Priority date: 1922-05-19
Filing date: 1922-05-19
Publication date: 1925-10-13
Anticipated expiration: 1942-10-13

Description

Oct. 13, 1925. 1,557,080

H. D. MuRnocK SHCRT CIRCUITING DEVICE 5 Filerlay 19. 1922 WITNESSES: INVENTOR @f He my l). /Wurdoc/f Patented Cet. 13, 1925.

UNITED STATES HENRY D. MURDOCK, OF WILKINSBURG, HOUSE ELECTRIC & MANUFACTURING VAN'IA.

PENNSYLVANIA, .ASSIGNOR TO WESTING- COMPANY, A CORPORATION OF PENNSYL- SHORT-CIRCUITING DEVICE.

Application filed May 19,

To all 'whom t may concern.:

Be it known that I, HENRY D. Mnnnoox, a citizen of the United States, and a resident of IVilkinsburg, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Short-Circuiting Devices, of which the following is a specification. l

My invention relates to short-circuitmg devices and it has particular' relation to centrifugally operated mechanism for employment with dynamo-electric machines to effect a repulsion operation during. the starting period and an induction operation during the normal operating period of the machine.

One of the objects of the invention is to provide a centrifugally actuated short-circuiting device that is simple in construction and inexpensive to manufacture.

Another object of the invention is to provide a device of the character described in l which the contact members may be easily adjusted relatively to the commutator seg ments.

A further object of the invention is to provide a device of the class set forth embodying comparatively few parts which may be quickly and easily assembled.

In the accompanying drawing:

Fig. 1 is a transverse sectional view of a portion of a dynamo-electric machine, taken on the line I-I of Fig. 2.

Fig. 2 is a longitudinal sectional view taken on the line II-II of Fig. 1.

Referring to the drawing, a portion of a dynamo-electric machine is conventionally illustrated as comprising a shaft 1 upon which a rotor member 2 provided with a commutator cylinder 3 is mounted for co- 40 operation with a stator member, not shown.

The rotor member 2 is provided, at one end, with a plurality of outwardly extending studs 4 to which a short-circuiting ring 5 is secured by means of screws G. The ring 45 5 may be spaced from the shaft 1 and is electrically insulated from the screws 6 by means of flanged sleeve members 7, of fibrous material, and from the studs 4 by means of insulating washers 8.

A plurality of spring contact members, indicated, as a whole, by the numeral 9, are secured to the inner face of the ring 5, adja cent to the periphery thereof, and extend to a point adjacent to the extremities of the 55 segments of the commutator cylinder 3.

1922. Serial No. 562,077.

Each of the contact members 9 is provided with a foot portion 10 which extends parallel to the face of the end of the cylinder 3 for contact with the segments thereof.

The portions 19 of the contact members 9 may be slotted, as indicated at 11, to compensate for any irregularities in the contact surface of the cylinder 3 that may exist by reason of slight differences in the length of the commutator segments and to insure an eflicient electrical contact therewith. The contact members 9 are each provided with a plurality of weights 12 which are riveted in apertures formed in the members 10, as at 13.

The contact members 9 are adjusted, with respect to the extremities of the commutator segments, by means of fingers 14 which are secured between the members 9 and the ring 5. The extremities of the fingers 14 are provided with curled portions 15 that are adapt ed to be engaged by the Contact members 9 and which provide seats or braces therefor. If it is desired to adjust the contact members 9, either toward or away from the ends of the commutator segments, the curled portions 15 of the fingers 14 may be bent outwardly or inwardly to correspondingly vary the position of the seat.

During the starting period, the contact members 9 are out of contact with the commutator segments and the machine therefore operates as a repulsion motor but, after the speed of the machine attains a. predetermined value, centrifugal force, acting on the weighted contact members, carries the same into engagement with the commutator segments and short circuits the windings of the rotor member which causes the machine to function as an induction motor during the normal operation thereof.

From the foregoing it will be apparent that, by means of the above described construction, a very inexpensive and efficient short-circuiting device is provided that comprises but a few parts that are easily manufactured and assembled.

I claim as my invention:

1. A short-circuiting device comprising a short-circuited member adapted to be fixedly secured to the rotor member of a dynamo-electric machine, and a plurality of resilient contact members carried by said shortcircuited member and having a free end projecting obliquely, inwardly toward the axis of the rotor member, said contact members being arranged to swing outwardly under centrifugal action for engagement with the commutator segments of said machine.

2. A short-circuiting device comprising a short-circ-uited member adapted to be fixedly secured to the rotor member of a dynamo-electric machine, and a plurality of weighted Contact members carried by said short-circuited member and having a free end projecting obliquely, inwardly toward the aXis of the rotor member, said contact members being arranged to swing outwardly under centrifugal action for engagement with the commutator segments of said machine.

3. A short-circuiting device comprising a supporting member adapted to be fiXedly Secured to the rot-or member of a dynamoelectric machine, and a plurality of spring fingers, each spring finger having an end portion secured to said supporting member, a free end portion projecting obliquely, inwardly toward the aXis of the rotor member and a weight attached at a point intermediate said end portions, said spring fingers being arranged to swing outwardly under centrifugal action for engagement with the commutator segments of said machine.

4. The combination with a coimnutatoi cylinder of a dynamo-electric machine, of

a short-circuiting device comprising a circular supporting plate secured adjacent to said commutator cylinder in spaced relation to the end-face of the saine, and a plurality of weighted spring fingers each having one end secured to said supporting plate, the free ends of said spring fingers projecting obliquely toward the inner portion of the end face of said commutator cylinder and arranged to swing outwardly for making a short-circuiting engagement with the end face of said commutator cylinder.

5. The combination with a commutator cylinder of a dynamo-electric machine, of a short-circuiting device comprising a circular supporting plate secured adjacent to said commutator cylinder in spaced relation to the end-:tace of the same, a plurality of Weighted spring fingers each having one end secured to said supporting plate, the free ends of said spring ingers projecting obliquely toward the inner portion of the end face of said commutator cylinder and arranged to swing outwardly for making ashort-circuiting engagement with the end face of said commutator cylinder, said spring-fingers being biased to positions out of contact with the commutator, and means for determining the extreme out-of-contact positions of said spring-fingers.

6i. The combination with a commutator cylinder of a dynamo-electric machine, of a short-circuiting device comprising a circular supporting plate secured adjacent to said commutator cylinder, in spaced relation to the end-face of the same, and a plurality of weighted spring lingers each having one end secured to said supporting plate, the free ends of said spring fingers projecting obliquely toward the inner portion of the end face of said commutator cylinder and terminating in a contact-making portion disposed substantially parallel to the endface of the commutator cylinder, said spring-iingers being biased to positions outof-contact with the commutator and arranged to swing outwardly under centrifugal action whereby said parallel contactmaking portions come into engagement with the face of said commutator.

7. The combination with a commutator cylinder of a dynamo-electric machine, of a to the end-face of the same, a plurality of weighted spring fingers each having one end secured to said supporting plate, the free ends of said spring fingers projecting obliquely toward the inner portion of the end face of said comniutator cylinder and terminating in a contact-making port-ion disposed substantially parallel to the endface ot the commutator cylinder, said spring-fingers being biased to positions outof-contact with the commutator and arranged to swing outwardly under'centrifugal action whereby said parallel contactmaking portions come into engagement with the face of said commutator, and means for determining the eXtreme out-of-contact positions of said spring-fingers.

8. The combination with a commutator cylinder of a dynamo-electric machine, of a short-circuiting device comprising a circular supporting plate secured adjacent to said commutator cylinder in spaced relation to the end-face of the same, and a plurality of straps of resilient material having end-portions secured to said supporting member and portions projecting obliquely toward the inner portion of said commutator cylinder, each obliquely projecting portion having at its free end a fiat contact making portion arranged to swing outwardly and make a wiping contact with the face of said commutator.

9. The combination with a commutator cylinder of a dynamo-electric machine, of a short-circuiting device comprising a circular supporting plate secured adjacent to said connnutator cylinder in spaced relation to the end-face of the same, and a plurality of sliort-circuiting weighted members having portions secured to said supporting member and portions projecting obliquely toward the inner portion of said commutator cylinder, each obliquely projecting portion having at its free end a flat Contact making portion arranged to swing outwardly to make a wiping contact with the face of said commutator, said strap members being biased to positions out. of Contact with the commutator, and means comprising strap portions disposed underneath said irst-mentioned strap portions and held b-y the same for determining the extreme out-of-oontaot positions to which said resilient straps are biased.

In testimony whereof, I have hereunto subscribed my name this 28th day of April HENRY D. MURDOCK.