US1713610A

US1713610A - Short-circuiting device for motors

Info

Publication number: US1713610A
Application number: US66213A
Authority: US
Inventors: George H Leland
Original assignee: Leland Electric Co
Current assignee: Leland Electric Co
Priority date: 1925-11-02
Filing date: 1925-11-02
Publication date: 1929-05-21
Anticipated expiration: 1946-05-21

Description

May 21,1929. G, L N

SHORTICIHCUITING DEVICE FOR MOTORS Filed Nov. 2, 1925 //V VE N TOR. GEORGE H. LELAND.

Patented May '21, 1929.

UNITED STATES 1,713,610 PATENT OFFICE.

GEORGE .H. LELAND, OF DAYTON, OHIO, ASSIGNOB TO THE LELAND ELECTRIC COM- iPANY, OF DAYTON, OHIO, A CORPORATION OF OHIO.

SHORT-OIRCUITING DEVICE FOR MOTORS.

' Application filed No'vember 2, 1925. Serial No. 66,213.

This invention relates to short circuiting device for motors. Electric motors of the type known as repulsion induction motors are so constructed that the will start as repulsion motors and after t ey have attained a predetermined speed will be automatically converted into induction motors. This is usually accomplished by means of a series of weights or contact members arranged circumferentially of the axis of the commutator and movable by centrifugal force into short circuiting contact with the commutator bars, a

yieldable member acting on the weights tomeans for so applying an annular contractile" band to the weights that the band will cause the contact portions of the weight to press firmly against the face of the commutator at all times.

Other objects of the invention will appear 'as the device is described in detail.

In the accompanying drawings Fig. 1 is 3 an end elevation, partly broken away, of a short circuiting device embodying my invention; Fig. 2 is a longitudinal sectional view taken centrally through such a short circuiting device and the commutator, show- 133 ing the weights in their retracted positions; Fig. 3 is a similar View showing the weights in their extended positions; Fig. 4 is a sectional view showing a slightly modified for of my invention applied to a commutator and 40 Fig. 5 is a similar view showing a further modification of the invention. In these drawings I have illustrated certain embodiments of the invention but it will be understood that these have been chosen for i the purposes of illustration only and that the device may take various forms without departing from the spirit of the invention.

As here shown, the short circuiting device isiapplied to a commutator comprising a body 7 portion 1 which is rigidly mounted on an armature shaft 2 and is provided with the usual circumferential series of commutator bars 3. Mounted on this shaft 2 and spaced some dis tance from the face of the commutator is a retaining plate or disk 4. This disk may be a band prevents any material sliding moveloosely mounted on the shaft so that it'is capable of both rotary and axial movement with relation thereto but its movement away from the face of the commutator is positively limited by a stop, such as a split ring 5 seated in a circumferential groove 6 in the shaft 2. Arranged between the disk 4 and the face of the commutator is an annular series of contact members or weights 7 which extend circumferentially of the shaft 2 and which are slidably mounted so that they may be moved outwardly by centrifugal force to cause the contact portions 8 at the outer ends thereof to be brought into short circuiting contact with the commutator bars 3, shown in Fig. 3. These weights may be of any suitable character and shape. Preferably they are tapered toward the axis of the shaft so as to provide flat surfaces between adjacent weights. A yieldable device is applied to the weights to resist their outward movement and the weights are preferably so constructed that this yieldable device will not only resist the outward movement thereof but will also cause the contact portions 8 thereof to be pressed firmly against the face of the commutator. The yieldable device may be of any suitable character but -I prefer that it should be in the form of a contractile hand because the elasticity of such m'ent of the same relatively to the weights and thereby minimizes the friction. As here shown, this contractile band is in the form of an endless helical spring 9. Each of the weights has a portion of its forward edge, that is the edge opposite the commutator, arranged to engage and fulcrum on the retaining disk 4 and, as here shown, the inner portions of the forward edges of the weights extend outwardly and rearwardly so as to provide slidable fulcrum points near the inner ends of the'weights. The outer portions of these forward edges of the weights extend. forwardly beyond the fulcrum point to form shoulders 10 which overhang the peripheral 100 edge of the disk 4; and constitute stops to limit the inward movement of "the weights. The

'contractile bandis so applied to the weights and the commutator. With such anarrangement of the band the tendency of the same is to cause each weight to pivot about its point of contact with the disk and thus hold the outer contact portion thereofagainst the face of the commutator. There are various ways .in which the contractile hand may-be so connected with the weights and in that found the device'shownin Figs. 1, 2-and .3, each weight is provided at its inner end witlian arm 11 which projects from the rear edge of the body of theweight toward'the commutes tor. In order to accommodate this arm the body l-of the commutator is recessed in its forward face, as shown at 12, and the arms 11 extend into this recess. Each of the arms is provided in its outer edge with a shallow re.-

cess 13 in which the annular hand 9 is seated. The recesses are preferablyforme'd near the are provided'in their inner portions and preferably near the inner ends thereof with-openings 18 through which a contractile hand 19- is threaded. Preferably the inner portions of the weights are widened so as to cause the annular ha'ndto engage the weights at a considerable distance in the rear of their centers of gravity and thus the band will tend .to rotate the weights about their fulcrum points 15 and press the contact points 17 thereof against the face of the commutator.

. Obviously, if desired, the outer-portions of and thespring.

the walls of the openin'gslS may be cut away to, facilitate the assembling of the weights In that form of the device. illustrated Fig. 5 the weights are ,shown at 20 and are similar in shapeto the plates 14 OfEFig. 4

' but instead of an opening through the. same their inner rear corners are cut away to form a recess 21. A contractile band22 is arranged in recess and is suspended from "the weights by-suitable connecting devices,

such as 23, which are so arranged that the force-of the band will be applied to the In that form of the device shown in Figs. 1, 2 and 3, the forward ends of the com- I mutatorbars are flush with the face of the commutator and the contact portions of the weights move over the commutator bars with a sliding or wiping action. Intho'sa forms of the device shown in Figs. 4 and '5, the

forward ends of the commutator bars overhang the face of the commutator and are weights 'atpoints between the respective centers of gravity'and the commutator.

provided with arcuate recesses 24 which "form the contact surfacesand which are vengagedby the contact points of the weightsp The contact points of the weights are curved to conform to the contour of the arcuate recesses 24,'so that'tlie'weights will engage the commu'tator barswith a butting contact'but the arrangement is such as to eliminate 'the'b urning or damaging of the contact faces due to sparking, as is fully-set forthjin my co-pend- 'ing application filed April 16,1925, Serial N o. r 23,524.

While I tain embodiments of invention 1 wish it to'be' understoodthat I .do not desire to be limited to the details thereof as various modi fica'tionsmay occur to a person skilled in the art. i i i Having now described invention, what I claim as new and desire to secure by Letters Patent, is:

1. In a short ircuiting' device for a commutator, a shaft on which said commutator is-mounted,'-a disk mounte'dmn said shaft,

spaced from said -commutator and normally.

have shown andtdescribed cer-i held against axial movement'in a direction away from said-commutatorya series of short.

circuiting weights arranged about said shaft between saiddisk and said commutator and capable of ra'dial sliding movementunder the influenceof centrifugal force, each weight on said disk and having a portion of its other edge in sliding contact with the face of said having a portion of that edge opposite saidcommutator arranged to fulcrum at all times commutator, anda contractile band'acting on the several weights at'pointsbetween their respective centers of-gravity and said'c'ommutator to resist their outward movement and to press said portions thereof respectively against the face. of said commutator and,

against said disk -2. In a shortcircuiting device for a-com'- mutator, a shaft on which said commutator is mounted,a disk mounted on said shaft, spaced from said commutator and normally held' against, axial movement in a direction away from said commutator, a series of short circuiting weights arranged about said shaft between said disk and said commutator and capable of radial sliding movement under the influence of centrifugal force, each weight having a portion of that edge opposite said commutator arranged to fulcrum. at all times on said disk and having a portion of its other edge in sliding contact'with the face of said commutator, each weight also having a part extending mentioned parts of said weights. I I

I 3.:In a short circuiting 'device, the combination with a shaft and acommutator mounted on said shaft, comprising a circumferential series of bars and havin a central toward said commutator, and a contractile band supported on the last 1 recess in the face thereof, ofa dis mounted on said shaft and spaced from the face of said commutator, an annular series of contact weights mounted between said disk and the face of, said commutator and arranged circumferentially of said shaft for sliding movement under the influence of centrifugal force into short circuiting contact with said bars,

each weight having a part arranged to fulcrum at 'all times on said disk and having another part extending into said recess in said commutator, and a contractile band supported by the last mentioned parts of said weights.

4. In a short circuiting device for a com mutator, a shaft on which said commutator is mounted, a disk mounted on said shaft, spaced from said commutator and normally held against axial movement in a direction away from said commutator, a series of short circuiting weights, arranged about said shaft between said disk and said commutator, capable of radial sliding movement under the influence of centrifugal force and each having a portion arranged to have short circuiting contact with said commutator, and a spring element acting on said weights atiall times to press the contact portions thereof against the commutator and to press other portions thereof against said disk.

5. In a short circuiting devicefor a commutator, a shaft on which said commutator is mounted, a disk movably mounted on said shaft and spaced from said commutator, means for limiting the movement of said disk in a direction away from said commutator, a series of short circuiting weights arranged about said shaft between said disk and said commutator and capable of radial slidin movement under the influence of centrifuged force, each weight having a contact portion adapted to have short circuiting contact with the commutator and another portion to engage said disk, and a spring element acting on saidweights to press said contact portions thereof againstsaid commutator and'to press. said other portions thereof against said disk and hold said disk against said means for limiting the movement thereof.

In testimony whereof, I afiix my signature hereto.

GEORGE H. LELAND.-

' CERTIFICATE OF CORRECTION.

Patent No. 1,713, 610;

Grantedhlay 21, 1929, to

GEORGE n. LELAND.

It is hereby certified that the above numbered patent was erroneously issued to "The Leland Electric Company,

i forest in said invention, asslgnee at the mm" H "Leland, and The Leland Electric Company, of

said corporation as shown by the records of assignments in this Patent should be read with this correction ther'e conform to the record of the case in'the Patent Office.

18th day of June, A. D. 1929.

7 been issued to the inventor, said Dayton, Ohio, a corporation of Ohio, interest only in said invention, office; and that the said Letters inthat the same may Signed and sealed this (Seal) whereas and patent should have being assignee of one-half r M. .J'. Moore,

CERTIFICATE OF CORRECTION.

Patent No. 1,713,610. Granted May 21, 1929, to

GEORGE H. LELAND.

It is hereby certified that the above numbered patent was erroneousiy issued to "The Leiand Electric Company, of Dayton, Ohio, a corporation of Ohio", as assignee of the entire interest in said invention, whereas said patent should have been issued to the inventor, said "Leland, and The Leland Electric Company, of Dayton, Ohio, a corporation of Ohio", said corporation being assignee of one-half interest only in said invention, as shown by the records of assignments in this off ice; and that the said Letters Patent should be read with this correction there in that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 18th day of June, A. D. 1929.

M. J. Moore,

(Seal) Acting Commissioner of Patents.