US1966057A - Brush actuating mechanism for electric motors - Google Patents

Description

July 10, 1934. v. J. WINKEL BRUSH ACTUATING MECHANISM FOR ELECTRIC MOTORS Filed April-4, 1953 2 Sheets-Sheet l e HNVENT ATTORNEYS July 10, 1934. v J, w K 1,966,057

BRUSH ACTUATING MECHANISM FOR ELECTRIC MOTORS Filed April 4, 1953 2 Sheets-Sheet 2 ATTORNEYS Patented July 10, 1934 UN IT-ED ATLES BRUSH ACTUATINGAMECHANISM FOR ELECTRIC'MQTORS Vincent J. winkeL-fwausau, Wis., assignor 701' one-half 'toFred .M. Winkel, Brooklyn,fN.'Y.

Application April 4, 1933, ,Serial.No..664, 304

lll Claims.

This invention relates, to improvements in brush actuating mechanisms for electric motors, and more particularly to brush mechanismsbf repulsion-induction motors, in which at least, one

v pair of short circuited brushes is employed in starting the motor, which brushes .are lifted away from the commutator after themotor has reached a predetermined speed.

One object of my invention is to provide a '10 brush, mechanism which is actuatedby electromagnetic influence to bring'the brushes intocontact with the commutator.

Another obj ectis to provide a mechanism which is simple, inexpensive to manufacture, eflicient and noiseless in operation.

Another object is to provide certain improvements in the form, construction and arrangement of the several parts whereby the above named andother objects may effectively be attained.

A practical embodiment of my invention is represented inthe accompanying drawings, in which Fig. 1 represents a detail verticalsection of so much of a repulsion-induction motor as will sufficientlyillustrate.theapplicationrof my improved brush actuating mechanism thereto with the .brushes in their operative position;

Fig. 2 represents a detail plan viewof the parts .shown in Fig. 1;

Fig. 3 represents a vertical section taken in the plane .of the line HI -1110f Fig. :1, looking in the direction of the arrows;

4 represents a similar view -with;the;parts in another position;

Fig. 5 represents a detail topplan of one of the brushes and the holder;

Fig. 6 represents a :diagrammatic view of the electrical connection .between the commutator bars and the magnetic coils;

Fig. '7 represents a detail vertical section-similar to Fig. 3.and illustrating amodified .form of electromagnet, and

Fig. 8 represents a diagrammatic view -of .the electrical connection between the commutator 7, bars and the magnetic coils.

' In the form shown in Figs. 1 to 6 inclusive,v

the shaft of the motor is denoted by 1,:.the rotor by 2, the bars forming the commutator by 3 and the stator by '4. In the drawings only two brushes 5 are shownin coaction withthe barsof the commutator .in the usual manner, although any suitable number may be employed. Each brush 5 is slidably mounted in a tubular holder 6 formed in a support 7 fixedto extend laterally '55 from a ring 8 carried by. the .frame9 of themotorr apredeterminedzspeed, a suitable device 27,,pref- 110 'The brush-5,-is.mounted in positionto be moved i in its ,holder6 into contact with the commutator by means of a flat coil spring 10, one end of which is fixed to a pin 11lsecur ed to the ring 8, while the free end engages. the brushand moves there- ;within a cut-awayportion-12of the holder 6. A curvedarmature ,13 ispivoted at Mon the outer end of the support '7-and is provided with afinger I15 arrangedinpositionto extend into arecess 16 formed in ,theholder (i,- the wall 17 of-which recess limits the downwardmovement of the finger 15f Theupwardimovement of the finger .15 brings it .into contact with an offsetportion lBof-the brush 5,which projects into the recess l6,and lifts the brush ,away from the commutator. A spiral, spring'19 interposedbetween.the finger .15 and a lug20 on. thesupport '7 serves to normally hold the armature and finger in theirupwardposition and the :brushaway, from the commutator. The downward .movement :of the armature 13 and finger 15,is accomplished by means of an elec- ,tromagnet composed, inthepresent instance, of two concentric'coils'of wire 21,22 woundinan- :nular recesses 23, 24 respectively iormed in a ysteel'core;25. The,coils-21,.22 are connected/t0, the bars 3 oi? thecommutatorby leads which have ,their ends permanently :fastened to the bars in any well knownor approved manner. 7 The core 25 is mounted to rotate withtheshaft 1 and insulatedtherefromby an insulating sleeve 26. LTo obtain a maximum magnetic attraction from :the electromagnet, .the. coils 21, .22 \are .connected .to the bars of the commutator .90 electrical .de- ..;greesapart, as shown diagrammatically. in Fig.6, which arrangement provides a two-,phaseeffect.

When-.electricalenergyis applied to the stator 4,

, .95 -tion .suflicient to movethe .armature 13 .toward the. coils and core against the tension of the spring 19 andcauses the .finger,l5 to move away fromthe ofiset portion 18 of the brush 5.t0 the wall 17 of the recess 16, while the spring 10 exerts its .pressure. onthe brushrto. force. it .onto the com- :mutator bars.

The pivotal mounting :of the curved armature 13 on thesupport '7 and theposition of the finger,

whemrestingon the wallet the. recesslfi, serve to .space thearmaturea slight distance from thepe- .riphery-rof thecore, therebyforming a'small gap .between thearmature and core andthuspreventring noisy contact of .the parts. As the. rotor nears erably a speed responsive device, of any well known or approved type, is arranged to be brought into contact with the ends of the commutator bars 3 to short circuit the commutator and thereby de-energize the coils 21, 22 and core 25 thus permitting the motor to run as an induction motor.

When the magnetic influence of the coils 21, 22 and core 25 is broken, the spring 19 is free to pull the armature away from the coils and core, while the finger 15 in moving with the armature lifts the brush 5 against the tension of its spring 10 away from the commutator bars 3, thereby eliminating all wear on the brush and commutator after the motor has attained its full speed.

In order to minimize eddy currents in the body of the core 25, a series of radially arranged slots 28 are disposed in the core, which slots extend from the periphery of the core to a point inwardly of the bottom of the annular recesses 23, 24. One radially disposed slot 29 is extended from the periphery of the core to the insulating sleeve 26 to avoid a closed secondary circuit for the coils 21, 22.

The brushes 5 are connected by leads 30 screwed to the ring 8 at 31.

While I have shown in Figs. 1 to 6 inclusive and have described a core having two annular grooves provided with coils of wire therein, which coils are connected to the bars of the commutator at 90 electrical degrees apart to form a two-phase electromagnet, I wish it understod that three annular grooves 32, 33, 34 and coils 35, 36, 3'? may be disposed on the core 38, as shown in Fig. '7 and diagrammatically in Fig. 8, in which form the leads of the coils are connected to the bars of the commutator at 120 electrical degrees apart, thereby forming a three-phase electromagnet. By this last named arrangement of the coils and their connections with the bars of the commutator, I find that a more uniform influence or pull is exerted throughout the full revolution of the rotor.

It will be understood that various changes may be resorted to in the form, construction and arrangement of the several parts without departing from the spirit and scope of my invention, and hence, I do not intend to be limited to the details herein shown and described except as they may be included in the claims.

What I claim is:

1. In combination with the rotor and commutator of a repulsion-induction motor, of a stationary holder, a spring pressed brush slidable therein, an oscillating armature for controlling the movement of the brush, means normally holding the brush out of contact with the commutator, and electromagnetic means coacting with the armature for actuating the holding means to allow the brush to move into contact with the commutator, said electromagnetic means comprising a core mounted to rotate with the rotor and provided with a plurality of annular recesses, a concentrically wound coil in each of said recesses, said coils being connected to the commutator and energized by current induced in the rotor.

2. In combination with the rotor and commutator of a repulsion-induction motor, of a stationary holder, a spring pressed brush slidable therein, an oscillating armature mounted on said holder for controlling the movement of the brush, means normally holding the brush out of contact with the commutator, and electromagnetic means coacting with the armature for actuating the holding means to allow the brush to move into contact with the commutator, said electromagnetic means comprising a core mounted to rotate with the rotor and provided with a plurality of annular recesses, a concentrically wound coil in each of said recesses, said coils being connected to the commutator and energized by current induced in the rotor.

3. In combination with the rotor and commutator of a repulsion-induction motor, of a stationary holder, a spring pressed brush slidable therein, an oscillating armature mounted on said holder, means on the armature for controlling the movement of the brush and normally holding the brush out of contact with the commutator, and electromagnetic means coacting with the armature for actuating the means on the armature to allow the brush to move into contact with the commutator, said electromagnetic means comprising a core mounted to rotate with the rotor and provided with a plurality of annular recesses, a concentrically wound coil in each of said recesses, said coils being connected to the commutator and energized by current induced in the rotor.

4. In combination with the rotor and commutator of a repulsion-induction motor, of a stationary holder, a spring pressed brush slidable therein, an oscillating armature for controlling the position of the brush with respect to the commutator, electromagnetic means coacting with the armature to permit the brush to move into contact with the commutator, said electromagnetic means comprising a core mounted to rotate with the rotor and provided with a plurality of annular recesses, a concentrically wound coil in each of said recesses, said coils being connected to the commutator and energized by current induced in the rotor, and automatic means for short circuiting the coils to release the armature and move the brush out of contact with the commutator when the rotor reaches a predetermined speed.

5. In combination with the rotor and commutator of a repulsion-induction motor, of a stationary holder, a spring pressed brush slidable therein, an oscillating armature, means thereon for controlling the position of the brush with respect to the commutator, electromagnetic means coacting with the armature to permit the brush to move into contact with the commutator, said electromagnetic means comprising a core mounted to rotate with the rotor and provided with a plurality of annular recesses, a concentrically wound coil in each of said recesses, said coils being connected to the commutator and energized by current induced in the rotor, and automatic means for short circuiting the coils to release the armature and move the brush out of contact with the commutator when the rotor reaches a predetermined speed.

6. In combination with the rotor and commutator of a repulsion-induction motor, of a stationary holder, a spring pressed brush slidable therein, an oscillating armature mounted on said holder for controlling the position of the brush with respect to the commutator, electromagnetic means coacting with the armature to permit the brush to move into contact with the commutator, said electromagnetic means comprising a core mounted to rotate with the rotor and pro vided with a plurality of annular recesses, a concentrically wound coil in each of said recesses, said coils being connected to the commutator and energized by current induced in the rotor, and automatic means for short circuiting the coils to release the armature and move the brush out of contact with the commutator when the rotor reaches a predetermined speed.

'7. In combination with the rotor and commutator of a repulsion-induction motor, of a stationary holder, a spring pressed brush slidable therein, an oscillating armature mounted on said holder, means on the armature for controlling the position of the brush with respect to the commutator, electromagnetic means coacting with the armature to permit the brush to move into contact with the commutator, said electromagnetic means comprising a core mounted to rotate with the rotor and provided with a plurality of annular recesses, a concentrically wound coil in each of said recesses, said coils being con nected to the commutator and energized by current induced in the rotor, and automatic means for short circuiting the coils to release the armature and move the brush out of contact with the commutator when the rotor reaches a predetermined speed.

8. In combination with the rotor and commutator of a repulsion-induction motor, of a stationary holder, a spring pressed brush slidable therein, an oscillating armature mounted on said holder and arranged to engage the brush to hold it out of contact with the commutator, and electromagnetic means energized by current induced in the rotor and arranged to coact with the armature to permit the brush to move into contact with the commutator, said electromagnetic means comprising a core and a plurality of coils wound thereon, said coils being connected to the commutator.

9. In combination with the rotor and commutator of a repulsion-induction motor, of a stationary holder, a spring pressed brush slidable therein, an oscillating armature mounted on said holder and arranged to engage the brush to hold it out of contact with the commutator, and electromagnetic means energized by current induced in the rotor and arranged to coact with the armature to permit the brush to move into. contact with the commutator, said electromagnetic means comprising a core mounted to rotate with the rotor and a plurality of coils concentrically wound thereon, said coils being connected to the commutator.

10. In combination with the rotor and commutator of a repulsion-induction motor, of a stationary holder, a spring pressed brush slidable therein, an oscillating armature mounted on said holder and arranged to engage the brush to hold it out of contact with the commutator, electromagnetic means energized by current induced in the rotor and arranged to coact with the armature to permit the brush to move into contact with the commutator, said electromagnetic means comprising a core and a plurality of coils wound thereon, said coils being connected to the commutator, and automatic means for short circuiting the coils to release the armature and move the brush out of contact with the commutator when the rotor reaches a predetermined speed. i

11. In combination with the rotor and commutator of a repulsion-induction motor, of a stationary holder, a spring pressed brush slidable therein, an oscillating armature mounted on said holder and arranged to engage the brush to hold it out of contact with the commutator, electromagnetic means energized by current induced in the rotor and arranged to coact with the armature to permit the brush to move into contact with the commutator, said electromagnetic means comprising a core mounted to rotate with the rotor and a plurality of coils concentrically wound thereon, said coils being connected to the commutator, and automatic means for short circuiting the coils to release the armature and move the brush out of contact with the commutator when the rotor reaches a predetermined speed.

VINCENT J. WINKEL.

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