US1580161A - Starting switch for motors - Google Patents

Description

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UNITED STATES 1,580,161 PATENTN OFFICE.

LAWRENCE PERSONS, OF CHICAGO, ILLINOIS, ASSIGNOR TO COOK ELECTRIC COM- PANY, 0F CHICAGO, ILLINOIS, A CORPORATION 0F ILLINOIS.

STARTING SWITCH FOR MOTORS.

Application filed May 11, 1923.

To all whom t may concern.'

Be it known that I, LAWRENCE M. PER- soNs, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Startlng Switches for Motors, of which the following is a specification.

In motors, especially of the alternating current type, it is usual to provide a starting circuit which is broken after the motor has attained its normal speed. The present invention relates to a starting switch of this type which shall be economical to manufacture, ellicientin operation, and which shall be of long duration.

The invention is exemplified in the combination and arrangement of parts shown in the accompanying drawing and described in the following specification, and it is more particularly pointed out in the appended claims.

In the drawing- Fig. 1 is a sectional View of a motor showing parts of the starting switch in elevation;

Fig. 2 is a View similar to Fig. 1, having the starting switch parts in section; and

Fig. 8 is a section on line 3-3 ofFig. 2.

In the drawing, the numeral 10 designates a motor shaft journaled in bearings 11 on a casing 12. Secured to the shaft 10 is an armature 13 having a cover plate 14 at the end thereof. Field poles 15 are supported by the casing 12 about the armature 13 in the usual manner. A collar 16 is interposed between the end of the armature 13 and the frame 12 to hold the parts in proper spacedrelation. Slidably mounted on the collar 16 is a sleeve 17 having arms 18 extending radially therefrom at opposite sides thereof.

A pair of arcuate members 19 are provided with hooks 20 which engage openlngs 21 in the end plate for the armature 13. These arcuate members 19 are provided with coil springs 22, one at each side of the sleeve 17, which tend to draw the members 19 inwardly. The members 19 are perforated at 23 to receive the arms 18 so that the inward movement of the members 19 slides the 4 sleeve 17 to the right, as viewed in Figs. 1

and 2.

The sleeve 17 is provided with a ring 24 secured to the end thereof in position to engage a conductor ring 25. The ring 24 Serial No. 638,207.

is made of hard fiber or other suitable insulating material. The ring 25 is supported by a series of hooks 26 disposed in circular arrangement about the ring 25 and mounted on an insulation plate 29 secured to the casing 12. The ring 25 is free to rotate, in the confines of the supporting hooks 26 and is resiliently pressed to the left, as viewed in Fig.v2, by springs 27 attached to the insulation block 29.

,A pair of-.contact members 28 are mounted on the insulating block 29 on the casing 12 and are in position to engage the contact ring 25 when the ring is pushed to the right by the insulator ring 24, as shown in Fig. 1. The contacts 28 have conductors 30 attached thereto so that when the contacts are con'- nected by the ring 25 the circuit is com'-y pleted through the starting coils of the motor.

l/Vhen the armature is at rest the parts are held in the position shown in Fig'. .l by the springs 22 so that the starting circuit is closed. When the armature attains full speed the arcuate members 19 are swung outwardly by centrifugal force to the position shown in Fig. 2, thus retracting the sleeve 17 and withdrawing the ring 24 from contact with the conductor ring 25. This permits the'springs- 27 4to force the conductor ring 25 away from the contacts 28 and break the starting circuit afterTthe motor has attained full speed.

At the time the motor starts to rotate the frictional contact of the ring 25 upon the springs 27 and contact members 28 will hold the ring 25 from rotation and' the ring 24 will slide upon the ring 25.` When the current isshut off and the motor begins to decrease in speed the ring 24 will engage the ring 25 and since at the time of engagement the ring 25 is free from contact with the terminals 28, it will begin to rotate the armature and will attain suflicient momentum so that when it is brought into .engagement with the contact pieces 28 it will'continue to Amove for a sufficient distance to provide a wiping engagement with the contact members, thus keeping the contact surfaces bright. It will be noted, however, that this wiping engagement occurs at the time that the current is shut off, but when current is flowing there is no movement between the contacting parts. The amount of relative movement is reduced to the'minimum necessary to keep the parts bright and never takes place when current is flowing so that the wear between the contacting parts of the make and break switch is reduced to a minimum, thus greatly increasing the life of the switch.

I claim:

1. A starting switch for a motor having a rotor, said switch comprising a contact member Supported independently of the rotor and rotatable about the axis thereof, spaced stationary terminals, and means on said rotor for actuating said contact member to connect said terminals and close said switch.

2. A starting switch for a motor having a rotor, said switch comprising a contact ring, and an insulated member on said rotor arranged to engage said contact ring to close said switch and to impart temporary rotary movement by frictional force to said ring at the time the switch is closed.

3. A starting switch vtor an electric motor having a stationary frame and a rotor therein, said switch comprising a pair of contact members stationarily mounted onl said frame, a contact ring rotatably mounted on said frame, and an' insulated member mounted on said rotor for engaging said ring to close said switch.

4. A starting switch for an electric motor having a stationary frame and a rotor therein, said switch comprising, a pair of contact members mounted on said frame, a contact ring mounted on said frame to rotate about an axis concentric with the axis of said motor and to move parallel with said axis, and a centrifugal governor member on said rotor :tor engaging said ring to close said switch when said rotor reaches a prev determined speed.

5. A starting switch for an electric motor havingl a stationary frame and a rotor therein, said switch comprising a stationary contact member mounted on said frame, a conductor movably supported adjacent said contact member, `and an insulated member mounted on said rotor for engaging said conductor to close said switch when said rotor attains a predetermined speed, said conductor being movable by contact with said vinsulated member in the direction of rotation of said rotor.

6. In a. starting switch for an electric motor having a stationary frame and a v`substantially diametrically member into engagement with said terminal member, said means being adapted to 1mpart a wiping movement to said contact pember when it engages said terminal memer. v

7. In a starting switch for an electric motor having a stationary frame and a rotor thereon, the combination with a terminal member for the starting circuit ot Said motor, of a contact member rotatable about the axisof said rotor for engaging said ter` minal member to close said switch, centrifugally actuated means for holding said switch' closed but permitting rotation of said rotor while said Contact member remains station# ary, said actuating means being arranged to impart movement to said Contact mem.

ber while closing said switch to `give a ,wip-

ing engagement between said contact meme' ber and terminal member.

8. In ,a starting switch for an electric motor having a rotor the .combination with a pair of terminal and a stationary frame,4

members mounted on said frame at points opposite one another, a contact ring for ngaging said terminal members being mounted on said frame for rotation about the axis of said rotor and movable in the direction of said axis into and out of engagement with said terminal members, springs for holding said ring away from said terminal members, a lring of in- Sulating'material carried by said rotor and movable into and out of sliding contact with said contact ring, centrifugal means for actuating said insulator ring to Vforce said contact ring into engagement with said terminal members and to impart slight rotation to said ringrelative to said terminal members at the time the switch is closed by said ring.

In testimony whereof I have signed my name to this specification on this 15th day

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