US1557052A - Short-circuiting device - Google Patents

Description

Oct. 13, 1925- 1,557,052

W. H. HIMES SHORT CIRCUITING DEVICE Filed m 11. 1921 lNVENTOR WITNESSES: 29 22 I War/fer Hh'frwes,

- ATTORNEY nected as to ensure uniform outward Patented Oct. 13, 1925.

UNITED STATES 1,557,052 PATENT OFFICE.

WALTER H. BIKES, OF PI'I'ISBUBGH, PENNSYLVANIA, ASSIGNOR TO WESTINGHOUSE ELECTRIC &' MANUFACTURING COMPANY, A CORPORATION 01' YENNSYLVAJNIA.

S HORT-OIRCUITING DEVICE.

Application filed Kay 11, 1921. Serial llo. 468,703.

To all wiwm it may concern:

Be it known that I, WALTER H. Hnuns, a citizen of the United States, and a resident of Pittsbur h, in the county of Allegheny and State 0% Pennsylvania, have invented a. new and useful Improvement in Short-Circuiting Devices, of which the following is a specification.

My invention relates to short-circuiting devices and it has particular relation to centrifugally operated mechanisms adapted for employment with dynamo-electric machines to effect repulsion operation during the starting period and induction operation during the normal operating period.

It has been observed, in devices of this general character, that the operation of centrifugally actuated weights frequently becomes impaired from various causes which results in non-uniform outward movement thereof, which causes an uneven contact between the short-circuitin elements and the ends of the commutator bars. Further iore,

when the centrifugally actuated dev as is located adjacent to the commutator end of the rotor member, it seriously interferes with the ventilation of the commutator.

One of the objects of my invention is to provide a device of the character described in which the. weights shall be so interconinent thereof under centrifugal ecti causing the shor't-circuiting eiemtr. move axially into contact wit tater bars with uniform pro to say, the weights are so 0 movement of each controls a movement in unison, eve there. move more treciy Another object of my inv" dispose the centrifug "y a as not to interfere a .1 in the vicinity of the co A further object is to pr the character desi ated readily accessible or adj pairs without the necessity 01 in in other parts of the machine.

11 the accompanying drawings,

Figure 1 is an end view of a centrifugaiiy operated short-circuiting device constructed in accordance with my invention.

Fig. 2 is a fragmentar side elevation of the mechanism illustrate in Fig. 1.

Fig. 3 is a fragmentary view of a contactcarrying plate illustrating the notches through which the weight-supporting brackets are adapted to PIOJBCt.

Referring to the drawings, 1 indicates a port1on'0f a commutator cylinder mounted upon a suitable spider 2 which is, in turn, carried by a rotor shaft 3. A ring or plate 4, which is concentric to the shaft 3 and spaced therefrom, is mounted for axial movement adjacent to the commutator 1 by means of diametrically opposed studs 5, which are carried by the spider 2 and project into apertures 6 in the ring 4.

The ring 4 is provided with a plurality of spring contact members 7 disposed in spaced rein-tron with respect to each other the periphery thereoi for eraloly comprises i. u arms 8 termine" portions 9 win engage the ends with a wiping acti after set forth.

* "sachets 10, each 0 plate 11 and outwarc portions 1%, are spider 2 at dianieti they project out etween the shaft 3 tches 18 formed -tty oi centrifu each comnrisin veight 15 thereof an (7 i i no iy mounts chets it) by i ward movement thereof and to reinforce the plate. The weights 15 are normally maintained in an innermost position and the contact members 7 out of "contact with the ends of the commutator bars by means of diametrically disposed com ression springs 22 which surround the stu s 5 and are disposed between the commutator spider 2 and the inner face of the plate 4 and tend to exert pressure in an outward direction against the plate 4, which, in turn, tends to move the weights 15 inwardly about their pivots 17.

When the machine attains a predetermined s d, centrifugal action will cause the weig ts 15 to move outwardly against the yieldable pressure of the springs 18 and 22 and to move the antifriction rollers 16 inwardly, thereby causing the plate 4 to move axially toward the commutator, bringing the contact members 7 into contact with the ends of the commutator bars, thereby short-circuiting the same. I

The pressure thus brought to bear upon the spring contact members 7 causes the arms 8 thereof to expand, thus exerting a sliding or wiping action against the ends of the commutator bars. This sliding action tends to remove any foreign matter that may have accumulated adjacent to the point of contact and insures an efficient electrical connection.

It will be observed that the plate 4 is in the form of a ring and is so spaced from the rotor shaft 3 that ample space is allowed between the inner circumference thereof and the shaft 3, thus permitting a free and unobstructed circulation of air adjacent to the commutator and precluding the possibility of the formation of dead air spaces.

Itwill be further observed from the foregoin that a vital feature of my invention resid es in the ability to obtain different performances of the device by varying the point at which the springs lS are attached to the levers 14. Thus, if the point of attachment 19 of the springs 18 to the outer end of the lever 14 is only sli htly farther from thepivot 17 of the lever than the inner point of attachment 20, the forces of the two springs will be nearly balanced, and very slight centrifugal force actuates the levers. However, if the outer point 19 is several times as far removed from the pivot 17 as therpoint 20, a comparatively igh speed must be attained before action can occur.

Also, it is considered desirable in the art that, once the movement starts, it shall proceed with increasing force and that it shall be impossible for the weights to move part way and pause or slow down. Such motion would be disastrous in a heavily loaded machine. In such event, the weights might move outward without enough momentum to ensure good electricalv contact. This would cause injury to the contact members.

It is for this reason that the outer point 19 is located on a radius through the pivot which is at right angles to'the axis of the spring. Thus, any movement of the weights will swing the s ring closer to the pivotal point and re uce the effective resisting moment of the spring. With the sprin resistance decreasing and the centri gaf; action increasing by reason of the greater radius of the weights, the action is certain to have an accelerating characteristic.

The electrical contact will always be itive and independent of the rate at w iiz the armature accelerates. If more sudden action is desired, the outer point may be carried to some such osition as 23 or beyond the right-angle radius which will cause a more gradual decrease in spring torque with a given movement.

Care must be taken to so locate the inner point 20 that, when the weights have reached the outer position, the torque at the inner end does not exceed that at the outer end for the device will be powerless to return itself to its normal position upon the deceleration of the motor.

I claim as my invention:

1. A short-circuiting device com rising a ring-member movably supported a jacent the end of a commutator cylinder and in s aced relation with respect thereto and to the shaft of a dynamo-electric machine,

said ring-memcontact members carried by d find sa1 cy er,

her for engagement wit yieldable means for normally maintaimngv said contact members out of engagement with said cylinder, and mechanism comprising a plurality of centrifugally actuated means spaced entirely away from the shaft for moving said contact members into engagement with said cylinder when a predetermined speed is attained.

2. In a dynamo-electric machine, the combination with a spider and a commutator cylinder mounted thereon, of a short-circuiting device comprising a plurality of supporting pins extending longitudinally from the end of said spider, and an annular plate movably mounted on said supporting pins and in spaced relation with res to said cylinder and with respect to the shaft of a dynamo-electric machine.

3. A short-circuiting device comprising a plate movably supported adjacent to a commutator cylinder and in spaced rela-' tion thereto, and with the shaft of a dynamo-electric machine to admit of the unobstructed circulation of air adjacent to said cylinder, a lurality of sprin contact members carrie by said plate or engagement with said commutator cylinder means for maintaining said contact members out of engagement with said cylinder, a pluralit of substantially diametrically oppo levers pivotally mounted adjacent said plate, each of said levers be1ng provided with centrifugally actuated weights at one end and an antifriction roller at the other end thereof for engagement with said plate to so move said plate as to cause said contact members to engage said commutator cylinder, and a plurality, of springs '60 connecting the outer extremities of each of said levers to the inner extremities of the diametrically opposed levers as to cause said levers to operate in unison.

4. The combination with a rotor member, of a switch comprising contact elements carried bysaid rotor member, an axially movable ring-member adapted to make con-- tact with said contact elements, axially disposed yielding means for forcing said ring member away from said contact elements, a pair of oppositely disposed, substantially longitudina 1y extending lever members en gaging said ring-member at their inner ends and carrying weights at their outer ends, means carried b said rotor member for pivotally supporting said lever me bers, and a link member connecting a p int on the inner end of one lever member to a point on the outer end of the other lever member.

5. The combination with the rotor mcmber of a dynamo-electric machine, of a winding thereon and means for shorhcir cuiting a plurality of portions of said winding, said means comprising contact elements carried by said rotor member and electrically connected to said winding per tions, an axially movable ring-member adapted to make contact with said contact elements, a pair of oppositely disposed, substantially longitudinally extending lever members engaging said ring-member at their inner ends and carrying weights at ,their outer ends, means carried by said rotor member for pivotally supporting said lever members, and a spring member connecting a point on the inner end of one lever member to a point more remote from the pivot on the outer end of the other lever member.

6. The combination with the rotor member of a dynamo-electric machine, of a winding thereon and means for short-circuiting a plurality of portions of said winding, said means comprising contact elements carried by said rotor member and electrically connected to said winding portions, an axially movable ring-member adapted make contact with said contact elements, a pair of oppositely disposed, substantially longitudinally extending lever members onga ging said ring-member at their inner ends and carrying weights at their outer ends, means carried by said jrotor member for pivotally supporting said lever members, and a pair of crossed spring members, each spring member connecting a point on the fingers adapted to make contact with said contact elements, axially disposed spring means for forcing said ring member away from said contact elements, a plurality of spaced lever members lying substantially in radial axial planes, the ends of said lever members adjacent rotor Winding being in operative engagement with said ringmcmber to press the same into engagement with said contact elements, the opposite or said lever m mbers being Weighted, and means for pivotally supporting said lever members intermediate their ends with their ring-member ends farther from the shaft than their pivots when the shaft is stationary and being movable to points substantially the some distance from the shaft said pivots.

combination with a commutating er, a supporting spider therefor, a for said spider, movable ring providing a ventilating opening near said shaft and carrying contact lingers adapted to cooperate electrically with said commutating cylinder, a supporting member extending from the end of said spider through said ring in spaced relation to said shaft,'and

centrifugal means mounted on said supporting member in operative relation to said ring for controlling its movement.

9. The combination with a commutating cylinder, a supporting spider therefor, a shaft tor said spider, a movable ring providing a ventilating opening near said shaft and carrying contact fingers adapted to cooperate electrically vvith said commutating' cylinder, means for providing a supporting member spaced axially outwardly from said ring While providing also for said axial ventilating opening, and centrifugal means mounted on said supporting member in operative relation to said its movement.

10. The combination with the rotor member of a dynamoelectric machine, of a winding thereon and means for short-circuiting a plurality of portions of said winding, said means comprising contact elements carried by said rotor member and electrically connected said Winding portions, a shaft for said rotor member, movable ring adapted to contact with said contact elements 1 prcyiding a /entilating opening near it, means ior providing a supporter spaced ally outWardly from ng opening, and centrifugal means supported b said supporting member in 1 ring for controlling 1 operative relation to said ring for controlling its movement.

11. A speed-responsive device comprising a shaft, an axially movable ring-member, a pluralit of spaced lever members lying substantia y in radial axial lanes, the ends of said lever members ad acent said ringmember being in operative enga ement therewith, the opposite ends of sai lever members being wei hted, means for pivotally supporting sai lever members intermediate their ends with their ring-member ends at substantially the same distance from the shaft as their pivots when said lever members are moved to their 0 rative positions by centrifugal force, and axially disposed spring means associated with said ring-member for opposing the centrifugal movement of said weights.

12. The combination with a rotor member, of a switch comprising contact elements carried by said rotor member, a shaft for said rotor member, a movable rin carrying resilient contact fingers adapte to make contact with said contact elements, axially disposed spring means for forcing said movable ring in an axial direction away from said contact elements, means for providing a tudinally outer en said lever members being pivoted at intermediate points on said pivots, respectively, and a pair of crossed spring members, each spring member connecting a point on the inner end of one lever member to a point more remote from the pivot on the outer end of the other lever member, whereby said spring members produce a resultant resisting moment opposing the centrifugal movement of the weights, the pzints of application of the spring members ing so chosen that said resisting moment is decreased as the weights move outwardly.

In testimony whereof, I have hereunto subscribed my name this 3rdday of May WALTER H. HIMES.

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