US945997A

US945997A - Centrifugal switch.

Info

Publication number: US945997A
Application number: US44720408A
Authority: US
Inventors: John B Wiard
Original assignee: General Electric Co
Current assignee: General Electric Co
Priority date: 1908-08-06
Filing date: 1908-08-06
Publication date: 1910-01-11
Anticipated expiration: 1927-01-11

Description

J. B. WIARD. CENTRIFUGAL SWITCH.

APPLICATION FILED AUG. 6, 190a,

Patented Jan. 11

Witmesses:

lnven'or John B. Wiard,

w dflfy UNITED STATES PATENT OFFICE.

Jomt B. wrann,

OE LYNN, MASSACHUSETTS, ASSIGNOR TO. GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

CENTBIFUGAL SWITCHL My invention relates to centrifugally operated switches for alternating current m0- tors, and is particularly applicable to small single-phase induction motors of the type having a starting winding which is opencircuited when the motor is up to speed.

Such motors have been provided heretofore with stationary collector rings concentric with the shaft, and contacts carried by the rotor which bridge the collector rings at starting, but when the motor is up to speed are-thrown away from the collector rings by centrifugal force.

My invention consists in a novel and simple form of centrifugally actuated contact adapted for use in such a structure.

It comprises a flexible tension member having its ends connected to points on the rotor on opposite sides of the shaft and contacts carried on the central portion of said member and pressed thereby against the collector ringsat starting, but adapted to be thrown awa from the collector rings by centrifugal orce when the motor is, up to speed. The tension member may consist of a single tension spring having its ends connected to ins on the rotor on opposite sides of the s aft, and the contacts may be in the form of rings strung on the middle portion of the spring. Insulating bushings may be placed inside the contact rings to insulate them from the spring.

My invention will best be understood by reference to the accompanying drawing, in

Y which- Figure 1 shows-a sectional view of an alternating current motor provided with a centrifugal switch with my invention;

Fig. 2 is an enlarged end view of the rotor and centrifugal switch;

Fig. 3 shows an enlarged cross-sectional detail view of a contact ring; and Fig. 4 is a diagram of connections.

In the drawings A represents the stator of an alternating-current motor provided with a primary winding a arranged in the usual manner.

B represents the rotor, which I have Specification 0! Letters Patent. Application tiled August 6,1908. Serial No. 447,204,

B. WIARD', a 'citi- ,E by the springs,

arranged in accordance die and pressed Patented Jan. 11, 1910.

shown provided with a squirrel-cage wind ing of well known construction, comprising conductors C and end rings D.

E represents a pair of stationary col-- lector rlngs supported on the frame of the motor concentrically with the shaft. These rings may be connected through suitable leads 6 to the starting winding of the motor F F represent a pair of tension springs, which have their ends attached to the ends of conductors on the squirrel-cage winding on opgosite sides of the shaft.

G represent collars on the springs between which'collars are conducting rings H, which are pressed against the collector rings and form contacts bridging the rings at starting. These rings H may h to insulate them from the springs.

The circu1t connections are shown in Fig.

4 in which a represents the main primary winding and an the starting winding in series with which are the collector rings E. At starting these collector rings E are bridged by the contacts H, so as to close the circuit of the starting winding a When the motor is up to speed, the contacts H are thrown away from the collector rings by centrifugal force, so as to open the circuit of the starting winding. 7

I do not desire to limit myself to the particular construction and arrangement of parts here shown, but aim in the a pended claims to cover all modifications w ich are within the scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States, is,

1. In an alternating current motor, stationary collector rings concentric with the motor shaft, a flexible tension member having its ends connected to points on the rotor of the motor on op. osite sides of the shaft, and contacts carried of said member presse thereby a ainst said collector rings and adapted to e thrown away from said rings by centrifugal force when the motor is up to speed.

is the central portion 1 be provided with insulating bushings 2. In an alternating current motor, sta- I tionary collector rings conqentricwith the motor shaft, a tens on spring having its ends connected to surroundin said spring near its midd e and pressed thereby against said collector rin s'and adapted to be thrown away from said rings by centrifugal force when the motor is up to speed, and insulating bushings within said rings insulating them from the spring 4. In an alternating current motor of the squirrel cage type, stationary collector rings oints'on the rotor of the motor on opposlte sides of the shaft,contact rin sof the shaft, contact rings surrounding the middle of the spring and pressed thereby against said collector rin s and adapted to be thrown away from said rings by centrifuga'l force when the 'motor is up to speed, and insulating bushings within said rings insulating them from thesprin In witness whereof, I have ereunto set my hand this'fourth day of August, 1908.

JOHN B. VIARD. g Witnesses:

JOHN A. MCMANUS, J r., CHARLES BARNARD.