US1425639A - Centrifugally-actuated short-circuiting device - Google Patents

Description

f H. GARCELON AND J. L. CHANTEMERLE.

CENTRIFUG'ALLY ACTUATED SHORT cmcumm: DEVICE. APPLICATION FILED MA-Y 3 I916. 1,425,639- Patented Aug. 15, 1922.

INVENTOR George H. Garcelon 2% Josggh L. Chanfemerle ATTORNEY G. H. GARCELON AND J. L. CHANTEMERLE. ICENTRIFUGALLY ACTUATED SHORT CIRCUITING DEVICE.

APPLICATION FILED MAY 3. 1916.

2 2 9 Z 1 .l H 5 H u am 1 m .i w u h lillllI- w 2 m d ,3! m a x P IIILIII WITNESSES Gear ' A'ITORNEY the motor.

NITED- STATES, PATENT oer-ice.

enonen H. GARCELON, or SWISSVALE, AND JOSEPH 'L. CHANTEIMEYRLE, or TURTLE CREEK, PENNSYLVANIA, ASSIGNORS 'ro 'WESTINGHOUSE ELECTRIC AND MAN- UFACTURING COMPANY, A CORPORAT ated Short-Oircuiting Devices, of which the following is a specification.

Our invention relates to centrifugally actuated short-circuiting devices for dynamo-electric machines, and it has particu lar relation to sin le-phase motors of the commutator type t at are adapted for re.- pulsion operation during the starting period and for induction operation after-a predetermined speed has been attained.

The object of our, invention is to provide a simple and effective device for short-circuiting the commutator. of such a motor that is automatically controlled by a device which is responsive to variations in the speed of Short-circuiting devices of the above-men- I. tioned type, as heretofore constructed, have trifugal force, have proven to be serious ob-' usually comprised a sleeve slidably mounted on the motor shaft and adapted to be moved longitudinally'of the shaft by centrifugally- .actuated levers- The short-circuiting device has usually ,been' maintained out of engagment with the commutator cylinder by a spring and has been so constructed that, as thedevlce was moved into engagement with the commutator cylinder, centrifugal force caused an outward radial movement of piv-.

otally mounted contact elements, thereby maintaining good electrical contact between the short-cirouiting device and the surface of the commutator cylinder. In order to utilize the effect of centrifugal force on the contact elements, it was necessary to provide a commutator cylinder of. special construction so that contact could be made with the inner peripheral surface of the segments of the commutator cylinder. This s ec'ial construction of the commutator cy inder and the 'necessity of providing contact elements that were capable of being actuated by censtacles in attemptingto simplify the con- Speciflcation of Letters Patent.

ION OF PENNSYLVANIA.

CENTBIFUGALLY-ACTUATED SHORT-CIRCUITING DEVICE.

struction and to reduce the cost of singlephase motors of the commutator type.

According to the present invention, we provide a novel form of short-circuiting device that is capable of both rotative and axial movement with respect to the motor shaft and commutator cylinder so that contact can readily be made with the end-sur- Patented Aug. 15, 1922. application filed May a, 1916. Serial No. 95,028. I

face of a commutator cylinder of the usual construction.

In the accompanying drawing, Fig. 1 is a view of a portion of a motor provided with a ShOIt-ClI'CIlltlIlg device constructed in accordance withour invention; Fig. 2 is a detail end view of the short-circuiting device shown in Fig. 1; Fig. 3 is a view, partially in section and partially in side elevation, of the short-circuiting device; Figs. 4, 5 and 6 are detail views, showing various parts of the device, and Figs. 7 and 8 are detail views showing modifications in the form of the contact plate. p

The motor comprises a stationary magnetizable member 1 provided with a winding 2 and an armature structure 3 carried on a shaft 1 that is rotatably mounted in bear- 9 that is movably mounted on an extension 10 of the spider 11 of the commutator cylin- I der 8. The extension 10 is provided with a helical groove 12 within which is located a pin 13 that projects from the inner peripheral surface of the plate 9. A governor support 14, preferably formed as shown in Fig. 4, comprises a hub-portion 15 that is adapted to be secured to the shaft 4 by means of a set screw 16, and oppositely disposed ln s 17 that are respectively provided wit a central aperture 18. Governor arms 19, as best shownin Fig. 5, respectively comprise crescent shaped plates 20 between which is secured a curved weight 21 by means of a rivet 22 and a pin 23. The pm 23is provided, at one end, with an .enlarged portion 24 and is riveted over at its other end against the surf ace of the lefthand plate 20. The weight 21 occupies only a portion of the space between the plates 20 so that their respective end-portions 25 are spaced apart and are adapted to embrace the lugs 17 of the support 14. The arms 19 are pivotally mounted on the support 14 by I means of pins 26 extending through the end portions 25 and the apertures 18 of the lugs 17 The arms 19 are held in a retracted position with respect to the shaft 4 by means of springs 27 respectively secured, at-their ends, between projections 28 provided on the support 14 and ears 29 provided on one of each pair of plates 20. The plate 9 is provided with diametrically arranged slots 30 within which project the enlarged portions 24 of the pins 23.carried by the governor arms 19. The plate 9 carries an annular contact plate 31 of substantially the same outside diameter as the commutator cylinder 8.

The contact plate 31 is provided with radial slots 32, thereby forming fingers 33 that are slightly inclined with respect to the body portion of the plate 31, as best shown in Fig. 3. Each finger 33 is provided at its end,

with acurved portion 34. The contact plate- 31 is also provided with slots 35 tlmie ada ted to register with the slots 30.

aving fully described the various parts embodied in the invention, the operation of the device is as follows. When the motor iS at r the springs 27 hold the governor arms 19 in a retracted position, and the pins 24, coacting with the slots 30, maintain the plate 9 in its extreme left-hand position, as shown in Fig. 3. The motor is then adapted to start as a repulsion motor. As the motor accelerates, the governor arms 19 tend to move outwardly about their pivots under the influence of centrifugal force. The springs 27 areso connected to the arms 19 that the moment arms through which the springs act, decrease as the governor arms move outwardly, so that movement of.the arms to their extreme outward positions is accomplished quickly when the motor reaches a predetermined speed. As thegovernor arms move outwardly, the pins 24, sliding in the slots 30, cause the plate 9 to rotate in a.

clockwise direction. The plate 9 being movably mounted-on the portion 10 and the pin 13 being slidable within the helical groove 12, it is apparent that any rotative move ment of the plate 9 will result in its simul-- taneous' axial movement towards the commutator cylinder 8. The-helical groove 12 is so proportioned that the curvedfportions 34 of the fingers 33 will make contactwith the end surface of the commutator cylinder 8 before the pin 13 reaches the end of its; travel in the groove 12. The initial contact of the plate 31 with the commutator cylinder will be made by a wiping movement of the curved portions 34 in both a radial and a rotative direction. It is apparent that good electrical contact will be maintained between portions 3 10f the fingers 33 and the commutator-cylinder 8, so long as the governor arms are in their extended positions, by reason of the factthat the somewhat resilient contact fingers 33 are distorted fromtheir original form when the plate 9 is in its extreme right-hand position.

While the fingers of the plate 31 are in contact with the commutator cylinder 8, thesegments of the commutator cylinder 8 will be short-circuited and the motor will operate as an induction motor. If, however, for any. reason, the motor falls below its normal operating speed, the springs 27 will retract the overnor arms 19 and cause them to withdraw the contact plate 31 from the surface of the commutator cylinder, whereupon the motor will be adapted for repulsion op.- eration, as before. It is apparent that our short-circuiting device is reliable and effective in operation for, since the contact fingers are formed from a single plate ot conducting material, there are no parts "to get out of order or to require inspection, as in therase of short-circuiting devices having pivotally mounted contact. fingers.

A modification in the form of the contact plate is shown in Fig. 7 wherein a flexible disk 36 is mounted on the plate 9. The disk 36 is provided with an offset portion 37, similar in form to the fingers of the plate 31. A. second disk 38 of smaller diameter is located intermediate the disk 36 and the plate 9, the disk 38 being preferably formed of material possessing considerable rigidity in order to reinforce the contact disk 36. A further modification is shown in Fig. 8 wherein a stiff disk 39 is formed with an offset portion 40 having a machined face 41 parallel to the plate 9.

While We have shown and described our invention in its preferred forms, it is not so limited-but is susceptible of various other minor changes and modifications within the scope of the appended claims.

\Ve claim as our invention;

1. In an electric motor embodying a rotatable commutator member, a short-circuiting device comprising a relatively movable contact member and means for causing both axial and rotative movement of said contact member relative to said commutator member.

2. In an electric motor embodying arotatable commutator member and a shaft therefor, a short-circuiting device comprisin a contact member loosely mounted on said shaft and means for causing combined axial and rotative movement of said contact member relative to said commutator member.

3. A short-circuiting device for electrical apparatus comprising a rotatable shaft, a

contact plate movably mounted thereon,

meansresponsive tovariations in the speed of said shaft for causing rotative movement .of said plate with respect thereto and means coacting with said shaft for causing simul taneous axial movement of said plate;

4. In a dynamo-electric machine, the combination with a rotatable shaft having a commutator cylinder comprising a plurality of spaced conductin bars, a contact member movably mountev upon said shaft, and means for moving said contact member in a helical path for engagement with the ends of said bars.

- '5. A short-circuiting device for electrical apparatus comprising a rotatable shaft, a contact plate movably mounted thereon, centrifugally actuated members for causing ro-' a commutator, of an automatic controlling device therefor comprising two op o'sing members, one of said membersbeing xedly mounted on the motor shaft, a short-circuiting ring carried by one of said members ad- 7 jacent the oommutator centrifugally acting means causing relative rotative movement of said members, means causinga relative axial movement of said members under the influence of said relative rotative movement to bring the short-circuit-ring in contact with the commutator, and means opposing the relative rotative and axial movements of said members.

& The combination with the armature of an alternating-current motor provided with -a commutator, of an automatic controlling device therefor comprising a member fixedly mounted on the motor shaft, a disk movably mounted on the shaft and interposed between said member and the commutator, a shortcircuiting ring carried by said disk' adjacent the commutator, centrifugally acting means causin relative rotative movement of said mem er and disk, means causing relative axial movement thereof under the influence of said relative rotative movement to bring the short-circuiting ring in contact with the commutator, and means opposin the relative rotative and axial movements 0% said member and disk.

9. A short-circuiting device for electrical apparatus comprising a rotatable shaft, a contact plate movably mountedthereon and capable of simultaneous rotative and axial movement with respect thereto, means responsive to variations inthe speed of said shaft forcausingTotative movement of said plate, and means whereby the axial movementis dependent on the degree of rotative movement. I

In testimony whereof, we have hereunto subscribed'our names this 28th day of April,

' GEORGEHHQGAROELONA,

JOSEPH L, CHANTEMERLE.

Images