US2473998A - Centrifugal switch - Google Patents

Description

June 21, 1949. J, T. JANETTE 2,473,998

CENTRIFUGAL SWITCH Filed April 2, 1945 Patented June 21, 1949 "UNITED PATENT OJF FI- C 'E John T. Janette, Kenilworth, Ill., assignor to Janette Manufacturing Company, Chicago, 111.,

a corporation of Illinois Application April 2, 1945, Serial No. 586,168

1 Claim. 1

This invention relates to centrifugal switches which may be used for various purposes but which are particularly intended to be used as component parts of electric motors, apparatus of this kind having been disclosed in my Patent No. 1,606,231. The present invention is intended as a general improvement in such switches and also as presenting novel construction and operating features.

Other objects are to produce a centrifugal switch containing comparatively few parts, a number of which may be formed of stampings for rapid and economical production; to provide a switch which will have satisfactory opening and closing characteristics; to provide a switch in which the movable member will be securely held when in closed position to prevent possible chattering or vibration; and to provide other novel features and improvements in operation which will be described more fully hereinafter.

In the accompanying drawings illustrating this invention,

Fig. 1 is a side view showing a motor armature or rotor with my switch applied thereto;

Fig. 2 is a front view of the parts shown in Fig. 1;

Fig. 3 is a view similar to Fig. 1 showing the switch in open position;

Fig. 4 is a side view taken at right angles to Fig. 1; and

Fig. 5 is a sectional view taken substantially on the line 5-5 of Fig. 2.

In these drawings, the switch is shown as a part of a motor having a rotor or armature 6 and driving shaft 1. The switch proper includes fixed brushes or contacts 8 and 9 which are connected in circuit with the starting windings in the usual manner. It also includes a contact ring or disc or movable switch member I which coacts with the brushes 8 and 9 to open and close the circuit. The ring or disc I0 is rigidly secured to a sleeve or collar I I which is formed of insulating material and slidably mounted on the shaft 1, and which is adapted to be actuated by the centrifugal means for opening and closing the switch.

For this purpose a bracket or support I2 is provided having oppositely disposed lugs or ears I3 which are secured to the rotor by means of screws I4. This support or bracket I2 also has oppositely disposed arms I and IB having transverse channels or guideways I I and I8 for the cylindrical weights I9 and 20 as shown. The ends of the weights extend through pairs of links or arms 2| and 22 respectively and. are held in position by any suitable means such as split rings 23. The

links 2| are fastened together by an integrally formed cross bar 24 and the links 22 by a similar bar 25. The outer ends or free ends of the links 2| and the links 22 are connected respectively by means of pivots or pins 26 and 21 with the insulating collar or sleeve I I which is provided with a rectangular portion 28 for receiving such pins.

Tension springs 29 and 30 extend between pins SI and 32 carried by the links or arms 2| and 22 and tend to draw the inner ends of these arms together as shown in Fig. l, which is the normal position of the parts when the motor is at rest. The inner ends 33 and 34 of the guideways I! and I8 serve as stops or abutments to limit the inward movement of the weights under the influence of the springs. These stops are positioned so that the center lines of the links will be at a slight angle only to the central plane of the rotor, and any thrust on the collar or disc tending to move the same to the left as shown in Fig. 1 will be so strongly resisted that the collar and parts attached thereto will be in substantially fixed position with respect to the shaft. This will prevent any tendency toward vibration or movement of the contact ring and the switch parts will therefore be held more securely in closed position.

When the rotor reaches a predetermined speed, the weights I9 and 20 will move outwardly or away from the center line of the rotor until the ,collar II strikes the base portion of the support or bracket I2 as shown in Fig. 3 and will, accordingly, move the contact member I0 out of engagement with the contacts or brushes 8 and 9 and open the circuit for the running position. I have found from actual use that the movement of the contact ring or disc I0 during its closing and opening movement is sufficiently rapid to avoid any undue arcing or injury to the contacts.

Having thus described my invention, what I claim is:

In a device of the character set forth, the combination with a rotatable member and a shaft therefor, of a base plate adapted to be fixed to the rotatable member and having outwardly extending branches with box-like guideways having broad flat engaging surfaces for the weights, cylindrical, weights extending through said guideways, pairs of connected links pivotally connected with the respective weights, an insulating collar slidably mounted on the shaft and pivotally connected with the pairs of links, a contact ring carried by said collar, pins through the respective pairs of links, springs extending between the pins tending to draw the weights inwardly, the arrangement being such that the inner ends of the 2,473,998 3 4 guideways serve as stops for the weights when REFERENCES CITED drawn inwardly by the springs and the contact ring will be in closed position with the center ifi g g i ffi are of lecold m the lines of the links at a small angle to the axis of p the shaft and when the weights move outwardly 5 UNITED STATES PATENTS under the influence of centrifugal force, the con- 'tact ring will be moved to open position and the 3 6223 g 3 base plate will act as a stop for limiting the inward l897405 'g 1933 movement of the collar. 2372064 Esarey 1945 JOHN JANETTE' 2,419,141 Johns et a1 Apr. 15, 1947

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