US1572928A - Short-circuiting device - Google Patents

Description

Feb. 16 1926.

w. H. HIMES SHORT CIRCUITING DEVICE Filed August 30. 1923 INVENTOR M a/Zer fihfiwes,

WITNESSES:

BY SMF'WQM I ATTORNEY Patented F eb. 16, 1926.

UNITED STATES PATENT OFFICE.

WALTER H. HIMES, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR T0 WESTINGHOUSE ELECTRIC & mmumcrunme company, A conronnrrou or PENNSYLVANIA- snonr-cmcurrme nnvrcn.

Application filed August 30,1923. Serial No. 660,120.

To all. whom it may concern:

Be it known that I, \VALTER H. HIMES, a citizen of the United States, and a resident ofPittsburgh, 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.

. My invention relates "to centrifugally actuated short-circuiting devices for dynamo-ele'ctric machines and it has articular re ation to single-phase motors 0 the commutator type that are adapted to operate, during the starting period, as repulsion motors and, upon reaching a pre-determined speed, as induction motors.

It has been found that the sliding friction commonly encountered in devices of the prior art is a highly undesirable element of the starting operation. It is furthermore necessary to provide a starting device having an action whereby the closed circuit between the commutatorsegments is effected, at a predetermined speed of rotation, with a quick and positive action. One object of my invention is to provide a short-circuiting device in which sliding friction is substantally eliminated.

Another object of my invention is to provide a short-circuiting device having a critical action, whereby the closed circuit is quickly established with a snap action I speed.

- upon theattainment" 'of predetermined A further object of any, invention is $0 provide a short-circuiting device} for dynamo-electric machines that is arranged asaself-contained' and simpleunit', detailed assembly and testing independently ofthe machine and permitting the units tobe easily interchangedor replaced.

. With the foregoing and other objects in;

view, my invention consists in the "arrangementand detailsof construction described and claimed herewith and illustrated in the accompanying drawings wherein Figure 1 1s a view in vertical section through the upper, half of a shoi't-circuiting device embodying mysihvention, a 'ortion' (30111 of the associated otor'flshaft an mutator cylinder bei gshown.

. Fig. '2 1s a view in end eleyation of the de vice il ustrated in Fig. 1, a part of the outer plate'being broken away.

vmounted between the" permitting ing a rotatable commutator 1 and a cooperating short-'circuiting device 2 which is mounted upon the commutator shaft 3. The commutator has a plurality of any standard construction and is provided with a smooth front-end face 5 having an inner portion '6 of insulating material.

Thenshort-circuiting device 2 comprises a,

hub member 7, two substantially'circular guide plates 8 and 9, aplurality of balls 11 of conducting material, such as bronze, guide. plates, and a substantially annular tension member 12 surrounding the balls and strain them in a central position.

v The guide plate or retainer 8 is secured in position against a flange 13 extending from the hub member adjacent to the end face of the commutator and is provided with a plurality of substantially radially dis posed slots 14. The outer guide plate 9 is of segments 4 ending to resecured in position against a shoulder 15 of the hub by means of a circular lock spring 16 wedged between the inner portion 17' of the guide plate and projecting portions 18 of a retaining ring memberlSa secured to the hub. Tlie inner portion 17 of the outer guide plate 9 has cut-out portions corresponding to the projections 18 of the retainlng member 18a, providing a bayonet joint,

as shown in Fig. 2,-which facilitates the as-" sembly and removal of the outer guide plate.

' The conducting halls are mounted loosely withinthe slots '14 and are adapted to move along predetermined paths upon the: end face ofthe commutator and to establish, in their outer position 11a, a closed circuit between a' plurality of ti e commutator bars 6 and the outer extrem ies "of the slots 14 in the guide plate 8. In Fig. 3 is shown the.

arrangement of a ball ll within a slot The ball is mountedloosely between lips 21 extendingfrom the guide .pIIate B and is forced into engagement wit the commutator face, 5 member 12, as will be'explained hereinafter. In the modification shown in Fig. 4, I em by the action of the tension 7 ploy in. lieu of the. 11 a plurality of rollers 11"; which may beef substantially pure copper, and which may-have conical circle "11 forrestr'aining the rollers -in;-the slots.

The annular tensio n'member is pref .erablymade of a closely coiled garter spring having a circular cross-section and having a wedge-like engagement between the outer guide plate 9 and the outer 'portions of the balls 11. Thewedge-like action of pring crowds the balls into their central p bgitions adjacentthe inner ends, of the s10 s 14 and in engagement th the com-- mutator end face 5. The 0 terplate ser'ves as a guide for the tension member 12 and has a central portion 19 disposed parallel to the'conunutator face 5, and merging, at a predetermined distance from the center, into a substantially conical portion. 22 extending 1 away from the commutator.

Upon the starting of the armature, there is a force tending move the balls outwardly under centri gal action along the aths determined by the slots 14' in the guide ,P plate 8 the outw rd movement of the balls eing opposed b the restraining force exerted by thegarter spring 12. As the motor 36 speed increases, the balls move out to a portion of their track where the garter spring is divertedui on the inclined portion 22 of the outer gui e member 9. At this moment,

the restraining. action of, the spring, is substantially reduced and the balls move out puic'kly, under the action of centrifugal orpe, to their short-circuiting positions, the final position .of one of the balls-being'inhdicated by dotted lines 11min Fig. 1. It

l centrifugal force acting .u'

should be noted that although the total tension of the spring is increased, the increased angle of a plication of itspressureon the balls actually results in reduced radial pressure but increased lateral pressure.

"circuit established by tlie'balls in their outer fined wedging action of the the inner guide plate or retainerB and the commutator bars 4. The guide-plate carries the armature currents and efiectivelyshunts the garter spr' latter from the I result were it permitted toacarry mirrent.

-12, in order to protect the estructive efiect' that might v Inshort-ci'rcuiting .devicesofthe prior art, the" ballshavebeen wedged, between the face of the commutator and theinclined of, a .gui'de member,

whereby'a roll only one of sai surfaces. The a movement could occur on remote 'rious critical speeds,

preciable fr1ct1on wh1ch occurred at the other surface as the balls moved. eitlfler out.-

increased the wear of the parts but also greatly increased the sluggishness and the -'wardly or'inwardly, not only very materially 'uncertainty of the movement to :and from.

the short-circuiting position. J

' In my invention, I have substantially eliminated all friction ina d'evice which is remarkably superior in' operation to anything heretofore known. The result ju mentioned is obtained by replacing e spring-pressed guide member with a stationary guide or abutment member, and

employing a coil spring which operates, in effect, like a flexible idler rollerbetween the balls and the abutment member, yieldably wedgi ng the balls into engagement with the end face of the commutator.- The convolutions of the spring which happen to be in 3 contact .withthe balls at any moment perform the function of idler rollers, and'the remaining convolutions perform the function of resilient connecting means. therefor. The balls thus roll on the commutator, and

face, the springrolls on the outer guide member, and the balls and spring roll-.-

',a ainst one another, thus rendering the device remarkably free from all frictional di/fficulties.

H the ub 7, the the interposed alls 11 and spring 12, may be quickly and cheaply assembled as a separate, self-contained unit, by methods wello.

adapted for quantity production, the slots 14 being-sufiiciently narrow to retain the balls 11. The short-circuiting unit may be fixed .on the commutator shaft 3 b any desired means, as indicated at 23. he

respective peripheries so that thespring cannot fly out in case of over-speeding of the.

short-circuiting device 2, including ide members 8 and 9, and p w plates. or guide members 8 and '9 have ad acent flanges or oilset portions 24 and 25 on their 14 to points on the peripheries of the balls from-the commutator, thereby ensuring the necessary wedging action of the balls between the commutator segments and the.

tions depends partially. u n 1 the wellend walls of the slots, in the short-'circuiting 5 us between mits the carrying of complete shortcircuitheextrtme simplicityof my device peringdevices m. stock, arranged to 'act at vaneed' of the motors for which they are intended. A device of my construction also occupies an unusually small space rendering the deviceially adapted for on motors having only a very limited space available. Q I

While I. have shown and described but in accordance-with the and an abutment member for said rolling contact wit-hone of said surfaces,

said rolling members being movable outwardly under the action of centrifugal force, a plurality of contact members adapted to be engaged by said rolling members in the course of their travel, and anti-friction means yieldably engaging said rolling members in rolling engagement therewith and with the other abutment surface for yieldably opposing the centrifugal movement of said rolling members. 2. A centrifugal contact-making device comprising a plurality of annularly disposed rolling members which are movable outwardly under the action of centrifugal force, a ,cylindrical commutator member having a plurality of peripheral segment members and having an end surface against which said rolling members roll, a coil spring surrounding said rolling members,

spring. 3. A centrifugal contact-making device comprising a plurality, of annularly disposed rolling members whichare movablle outwardly under the action of centrifugal force, a cylindrical; commutator member having a plurality of peripheral segment members and having'an end surface against which said rolling members roll, a coil spring surrounding said rolling members, and an abutmentmember for said spring, said abutment member having a conical surface,- the periphery of which is furthest removed from said end surfacek 4. A centrifugal contact-making device comprising a plurality of annularly disposed rolling members which are moved outwardly under the action of centrifugal force, a cylindrical commutator member having a plurality of peripheral segment members and having an end surface against which said rolling members, roll, a coil spring surrounding said nailing, members, and an abutment member for said spring, said abutmentfmember having an inner surface substantially normal to the axis of rotation, merging into an outwardly inelinedfl surface nearer its peripheral edge.

5. A centrifugal contact-making device comprising a plurality of annularly disc posed rolling members which are movable outwardly under the action of centrifugal force, a cylindrical commutator member having a plurality of peripheral segment:

cured to said hub in sp members and having an end surface against which said rolling members roll, a coil spring surrounding said rollingmembers, andm'eans for providing an abut-ment surface for said spring, further apart near their outer edges than their inner edges.

6. A centrifugal contact-making device comprising a plurality of annularly disposed rolling members which are movable 7 outwardly under the action of centrifugal force, a cylindrical commutator member having a plurality of peripheral segment members and having an end surface against whichsaid rolling members roll, spring surrounding said rolling members, andineans for-providing an abutment surface for said spring, said surfaces being further apart nearv their outer edges than their inner edges, and the nner portions 5 of said surfaces being more nearly parallel than the outer portions thereof.

7. A centrifugal contact-making device comprising .a"plurality of annularly disposed spherical members which are movable outwardly under, the action of centrifugal force, a commutator cylinder having a plurality of peripherally located segments and having an end surface against which said spherical members roll, a coil spring surrounding said spherical members, and means for providing an abutment surface for said spring.

-8. A self-contained speed-responsive at-- tachment comprising a hub, a securedthereto and having substantially radially. disposed slots, an abutment plate secured to said hub in spaced relation to said guide plate, a plurality of annularly disposed roller'mem ers disposed a in the'105 space between said p ates and having their,

rolling surfaces projecting through 'said slots, respectively, means for preventing the passage of the entire roller membersthrough said slots, and a coil springsur- 1 rounding said roller'member and engaging said abutment plate.

9. A self-contained speed-responsive attachment comprising ahub, a guide plate seciired thereto and having sii bstantially radially disposed slots, an abutmentplate secured to said hub in spaced-relation to said guide plate, -a pluralityof annularly disposed balls disposedt-in' the space between said plates and projecting-partially through said slots, respectively, and a coil spring surrounding-said balls and engaging said abutment plate.

10. A self-contained srdeed-responsive at- ,tachment comprising a hub, a guide plate.

secured thereto and haying substantially radially disposed slots, anabutment plate seacedrelation to said; guide 'plate, plurality of annularly/disposed roller members said surfaces being 7" guide plate .9

disposed in. the space 3 between said plates and having their rolling surfaces projecting through said slots, .spectively,

means for preventing the passage of the entire roller members through-sa d slots, and a 0011' spring surrounding sa1d roller members and engaging said abutment" plate, whereby said roller members may move outwardly under the operation of centrifugal force against the reaction of said spring, the outward movements of said roller members beinglimited by the outer ends of said slots, the outer portion of said guide plate being inclined toward said abut- I ment plate whereby said roller members, in

their extreme outer positions, are forced away from said abutment plate by the cen trifugal force pressing the roller members against. said slot-ends.

11. A self-contained speed-responsive attachment comprising a hub, a guide plate secured thereto and having substantially radially disposed slots, an abutment plate secured to said hub in spaced relation to said guide plate, a'plurality of annularly dis osed balls disposed in the space between sai' plates and projecting partially through a said slots, respectively, and a coil spring surrounding said balls and engaging saidabutment plate, whereby said balls may move outwardly under the operation of centrifugal force against the reaction of said spring, the outward movements of said balls being limited by the outer ends of said slots, the outer portion of said guide plate being inclined toward said abutment plate whereby said balls, in their extreme outer'p'ositions, are forced away from said abutment plate by the centrifugal force pressing the balls against said slot-ends.

12. A self-contained speed-responsive attachment comprising a secured thereto and having substantially radially disposed slots, an abutment plate secured to said hub in spaced relation to said guide plate, a plurality of annularly disposed roller members disposed in the s ace between said plates and having their r0 ing surfaces projecting through-said slots, respectively, means for preventing the passage of the entire roller members through said slots, and a coil spring surrounding said I roller members and eng'agm said abutment plate, said abutment plate being bent outwardly whereby said roller members are cause to movevinto short-circuiting -.posi tionswith a snap action.

13.. A self-contained speed-responsive attachment comprising a hub, a guide plate secured thereto and having substantially radiall disposedslots, an abutment plate secure to said hub in spaced relation to said .guide late, a plurality of annularly disposed alls disposed in the space between said plates and I projecting partially through said slots, resppctively, and a coil ub, a guide plate a sur ace by which said weight member is guided as it moves under the action of centrifugal force and means for yieldingly re-- straining said weight member agalnst outward radial movement, said movement being limited by theouter end of said slot, said slot-end engaging said weight member on the side opposite to said surface, whereby said weight member, in its extreme outer position, is wedged, by centrifugal action, between said contact element and said slotend.

15. A speed-responsive, circuit-closing device comprising aguide plate having a disposed slot, a roller member having a rollin surface extending partially through sai slot, means for preventing the passa e of the.

entire roller member through sai' slot," a

contact element having a surface in contact with said partially extending rolling surface, and means for yieldingly restraining said roller member, against outward radial movement under centrifugal action, said slot being closed at its outer end to limit said movement, the outer portion of said guide plate being bent away from said surface, whereby said roller member, in its extreme outer position, is wedged, by centrifugal 16. A speed-responsive, circuitclosing device comprising a guide plate having a substantiallradially disposed slot, a spherical member aving a surface extending partially through said slot, means for preventing the passage of the entire spherical member through said slot, a-contact element having a surface in contact with said partially exaction, between said contact element and said slot-end.

tending surface, and means for yieldin gly restraining said 'spherical -memberoutward radial movement under centrifugal to limit said movement, the outer portionof '11-) action, said slot being closed at its outer end said guide plate being bent away from said surface, whereby said spherical-member, in

its extreme outer position, is wedged centrifugal action, between said contact element and said slot-end.

17. The combination with the o unmutator cylinder of an electric motor; of a speedresponsive, circuit-closing device comprisi a guide plate disposed adjacent to the and c said commutator cylinder and havingri' plurality of slots, a plurality f annularly d weight members movable in sai dis-v slots} under the action of centrifugal forceand means for yieldingly restraining said weighting restraining member surrounding said members against centrifugal movement, said slots having closed ends for limiting said centrifugal movement and for so engaging said weight members as to cause the ce-ntrifugal action to wedge the weight members between said commutator cylinder and said slot-ends.

18. The combination with the commutator 10 cylinder of an electric motor, of a speed-re-7 ,sponsive, circuit-closing device comprising a guide plate disposed adjacent tothe e-nd'of said commutator cylinder and having substantially radially disposed slots, a plurality of annularly disposed spherical members movable in said slots under the action of centrifugal force and means for yieldably restraining said @spherical members against centrifu al movement, said slots having closed ends for limiting said centrifugal movement and for so engaging said spheri cal members as to cause the centrifugal action to wedge the spherical members between said commutator cylinder and said slot-ends.

-19. A close-circuiting'device for a rotor of an electric machine comprising a plurality of spherical members adapted to roll outwardly against the endsurface of said rotor under the influence of centrifugal force and a rolling tension member restraining said spherical members in a central position.

20. A close-circuiting device for a rotor of an electric machine comprising a plurality of annularly disposed spherical members adapted to roll outwardly against theend surface of said rotor under the influence of centrifugal force and a tension member of substantially circular cro-ss-section'surrounding said spherical members and opposing said movement. I

21. A centrifugal device comprising a plurality of members adapted to move outwardly under the influence of centrifugal force and means including a yielding member surrounding said plurality of members and tending to retain said members in central positions, said means being so arranged that the. force exerted by said yielding member upoii said plurality bf members diminishes during the latter portion of the movement. 22. The combination witha dynamo-electric' machine, of a close-circuiting device comprising a plurality of members arranged to move from central positions to outer positions, a yielding encircling member for opposing said movement and means whereby,

when said machine attainsa predetermined speed, .said members initially move slowly and later move quickly tosaid outer positions. v

23'. The combination Witlna rotatable commutator member of an/ electric -ma-chine, of

a closevcircuiting device comprising a plurality ofspherical members arranged to move outwardly area e r g fi ce a y el spherical members for opposing said movement, and a guide means for sa1d restraining member, said gu de means oa-usmg the initial "outward movement of said spherical membersto be opposed by substantially the full action of said restraining member and causing the opposing action subsequently to become less efiectiverwhereupon said spherical members move with an increased velocity to close-circuit said commutator member.

24.. The combination with a rotatable commutator member of an electric motor, of a plurality of spherical close circuiting members arranged to move outwardly under centrifugal force, a. yielding tension member surroundin said spherical members for restraining sai movement, a guide member for said spherical members and a guide member for said tension member whereby, upon the acceleration of sa1d motor, sa1d spherical members move outwardly, said guide member causing said spherical members, upon reaching predetermined portions of their paths, to displace said tension member and to close-circuit said commutator with a snap action.

25. A short-circuiting device for the commutator cylinder of a dynamo-electric machine comprising a plurality of spherical contact members, means adapted to retain said members in spaced relation for engagement with the end of the commutator cylinder and to guide the members in substantially radial paths, means for engaging said spherical members and placing the same under stress, and means for causing said spherical members, upon reaching a predetermined angular speed, to shift the point of engagement with said means and to move quickly to their short-circuiting position.

26. In combination with a rotatable commutator member of an electricmachin e, a plurality of spherical close-circuiting contact members arranged to move outwardly under centrifugal force, an annular tension member of substantially circular crosssection surrounding said spherical contact members and tending to retain said members in central positions, and guide means for causing said spherical members, upon reaching a predetermined speed, to move said tension member at an angle to their paths and thereby-diminish. the restraining action exerted upon said spherical contact members. i

27. A short-circuiting device for a dynzv moelectric machine comprising a commutator, having an inner body portion and commutator bars mounted upon its circumfernce, a ball cage mounted adjacentto said commutator and having two substantially circular members, one of said members facing said commutator and being provided with'a plurality" 'of substantially radially extending slots, the other member being in spaced relation thereto and provided with .tension member of "circular cross-section surrounding said balls and adapted to actuate saidv balls into central positions throu h a wedge-like engagement .between v said'balls and the outer member of said cage. 4 i

28. A short-circuiting dev ce for a commutator of a dynamo-electric machine, com- Y L prising a hub-member adapted to be-secured 1n abutment to said commutator,- a circular cage mounted uponsaid hub member consi'st-ing of two circular members, one of said members facing the end of the commutator and being provided with a plurality of substantially radiall disposed slots, another member in space relation thereto and having-a central portion disposed parallel to the end of said cgmmutator and mar ing into an outer portion extending away in said commutator, balls, of. conducting ma terial mounted loosely within the slots of 7 the slotted'cage memberand the commutator said cageand adapted to engage the end ortion of said-commutator and to establis -in theirouter position, closed circuits between in central bars, and an annular tension member of circular cross-section surrounding said balls? wi hin the cage and having wedgeelike en agement between the outer port on of said balls and the wall of the outer eage member, said outer cage member bein also" provided upon its circumference. with a flange adapted to limit the outward move-- ment of said tension member.

29. A short-circuitin dev ce for a commutator of a dynamo-e ectric'machine consisting of a demountable cage comprising a 1 substantially cylindrical hubmember adapted to be'secured upon the shaft in front of said commutator, a ball guide late secured to a flange extending from sai hub memberfl adjacentto said commutator, a

second guide member having a central ,por-

tion parallel.- to the front of'said conunut'ator and the outer portion extending away from -said coinmutator,- a bayonetjoint means for securing said second guide member to said hub member in" spaced relation to said ballguideg said ball.

guide having substantially radially disposed slots therein, a ball of conducting material mounted in each of said slots at (1 adapted to move loosely; between said gill and an annular arter spring surrounding said balls'and a' apted to retain. said balls itions-and in engagement with'j'the en fpo'rtion-of said commutator.

- 'In testimony whereof La d-1 this 1am dsyaiot subscribed my namel- August, l) 23; A

ide plates .5

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