US2285577A - Switch - Google Patents

Description

7 45 w a f; M 3 a 7 e a w 2 a, i a 5 4 H 4 on 5 m 1.25 3 4 4 Y.

6 O3 3 nt 3 a2 Eww s w .m z w Z M 1 WW; 0Q my WITNESSES:

Patented June 9, 1042 SWITCH Clarence E. Gary, Forest Westinghouse Electric '6 East Pittsburgh, Pa.. a corporation of F y, Pelinsy Hills, Pa., llligno i Manufacturing m Application September 21, 1938, Serial No. 230.987

BOIahns.

This invention relates to switches.

Among the objects oi my invention is the provision or a switch oi simple construction, which shall be easy economical to manuiacture; and to provide a novel type of spring biasing action to maintain the switch in open or in closed position.

A further object of my invention is to provide a transfer switch for controlling either of two circuits that shall have a simple construction in which the switch shall be positively biased to its open neutral position and positively biased to either of its closed positions.

In a switch of one form embodying my invention, two stationary contacts are provided to be bridged by a movable bridging contact. The bridging contact is mounted upon a rotatable post, and it is biased either to the open position or to the closed position by the action of an external pressure spring that presses radially inwardly against a rectangular element that is transverse position. In the neutral position, the spring engages the shorter surfaces of the rectangular section, and the pressure forces are opposed and symmetrically in alignment relative to the plane of the center line of the post. When the Post is turned to move the trailing comer edges of the rectangle beyond the center line plane. The spring then presses against both trailing comers of the rectangle in such manner as to establish a force couple that biases the bridging member into positive engagement with the stationary contacts.

position;

Fig. 5 is a side view oi the rectangle and spring to Fig. 4 showing the of Fig. 4;

Fig. 6 is a view similar rectangle and spring in operated position;

Fig. 7 is a side view of the elements of Fig. 8; and

2, of the force to assemble, and which shall be Fig. 8 is a schematic view illustrating the manner in which the bridging contact engages one set of stationary contacts.

As shown in the drawing. the switch i consists of a main molded base 2 on which are supported one pair of contacts 3 and In for one circuit, and

circuit. A bridging mlete the circuit between either set oi con- In order to operate the bridging contact I, a stem or post I is provided, the upper end of which is threaded and fitted into a metallic insert 1 in a head screw 8 that fits into a recess in the upper end of an operating and rotating button II. The rotating button iii is provided with an operating portion II, and an apron II that ilts over a projection ll of the body 2. ating button it is also provided with a depending e rtension it having a central opening or nona biasing spring embodies a central portion II or annular shape central annular section II, so that the entire spring unit is or substantially U-shape when viewed from the side. The two side fingers 23 and 24 are slightly re-entrant and the entire unit is made of highly resilient spring steel so that the fingers may exert a substantial pressure against an element oi'appropriate size between them.

In order to cooperate with the spring 20, a rectangular enlargement 15 is provided as an integral part on the operating post I, to at between the two flngers 23 and 24 of the spring 20.

The rectangular element 25 is normally arranged with its longer dimension in line with the pressure'iingers 22 and 24 (Fig. 4), and is mounted symmetrically with the axis of the post 8, so that normally the pressures from the fiat spring fingers 22 and 24 will oppose each other as distributed forces against the end surfaces of the rectangular element parallel to the longitudinal axis of the rectangular section 25. 'The fiat spring fingers thus impress their pressure biasing forces against areas of the element 25 to hold the bridging contact in its neutral position against casual displacement when the bridging contact is in such neutralposition.

when the rectangular element 25 is rotated through the angle necessary element against the stationary contacts, the spring fingers 23 and 24 will momentarily be separated an additional amount necessary to permit the diagonal of the rectangular element to move itself between the two spring fingers 23 and 24, and the rectangular element will then continue to move past such position until it occupies the position shown in Fig. 6, where the spring fingers are closer together. The diagonal of the rectangular element is then overcenter and out of alignment with the center line through the springs, and the trailing corner edges 25a and 25b of the rectangular element are on opposite sides of the center line through the springs, and are engaged by the respective spring fingers 23 and 24 with line contact, at which the pressure force of the spring fingers are concentrated.

The two springs 23and 24 where they engage the trailing corner edges 25a and 26b of the rectangular element, now impose a couple of concentrated forces tending to turn the rectangular element in the same direction in which it has been moved from its neutral position, and thus impress a biasing force to maintain the bridging contact 5 in positive engagement with the pair of stationary contact members 3 and 3a, or 4 and 4a, depending upon which direction the bridging contact has been moved. Since the arrangement is symmetrical, the same condition holds whether the rectangular control element 25 is rotated in one direction or the other, from its neutral position. Rotation of bridging contact member 5 relative its supporting bracket i5 is obviously limited in extent by the adjacent arcuate wall of base member 2 (Fig. 3).

Figs. 6 and '7 illustrate, further, how the rectangular element 25 is engaged by the spring fingers 23 and 24, when'the rectangular element is rotated with the operating shaft or post to move the bridging element 5 to engage either pair of the stationary contact members;

. In Fig. 8, I have illustrated in simple form the manner in which the bridging contact 5 engages one pair of stationary contacts 4 and 4a;to complete the circuit between them.

In order to retain thebiaslng spring 20 in position where it will function, the molded base 2 is provided with two side slots 30 and 3| within which the outer .curved portion of the spring fingers 23 and 24 will fit, and loosely position themselves, to prevent rotation of the spring as a unit in response to the oscillating movements of the rectangular element 25 by the control shaft 6.

' When the unit is assembled, the spring is merely dropped into its position, and the post is extended through the opening 22 in the spring to a position where the outer end of the post may be locked by the head nut 8. Thereafter, when the button It is rotated to oscillate the post 6 and the pivoted bridging contact 5, the spring 20 will remain in relatively fixed position against rotation, while to move the bridging the fingers 22 and 24 will be free to move in response to the minimum or maximum space required between them according to the position of the rectangular element 25.

The base 2 is provided with two bolt holes I4 and 25 in the-side walls to permit the base to be secured to a suitable base. Access to the bolt holes is available through channeled slots 36 and 31 that are depressed sufliciently below the top of the base to remove the hazard of short circuiting between any of the contacts and the fastening bolts.

By means of the simple rectangular element on the operating post, in cooperation with the biasing spring, a positive pressure may be maintained between the bridging contact and the stationary contacts. The construction is simple and economical and serves as an effective toggle in neutral position, as well as in either operating position.

My invention is not limited to any specific details that are illustrated since these may be variously modified without departing from the spirit and scope of the invention as set forth in the appended claims.

I claim as my invention:

1. A switch comprising a stationary contact, a movable contact, a rotatable member supporting the movable contact and movable therewith through a predetermined angle to engage the stationary contact, a rectangular element mounted on and transversely of the rotatable element, a pair of leaf springs rotatably mounted on said member and disposed to engage and press against opposite surfaces of the rectangular element in its position corresponding to the normal disengaged position of the rectangular element, and means for holding the leaf springs against rotary motion in response to movement of the rectangular element.

2. A switch comprising stationary contact members, a bridging contact member, a rotatable shaft to oscillate the bridging contact into engagement with the stationary contacts, an element on the shaft presenting a flat pressure surface, and pressure means presenting a pressure area against the pressure surface, said means including an annular ringfreely encircling the shaft and resilient fingers extending outwardly from the ring and extending radially inward to engage the element on the shaft on opposite surfaces thereof and means for restraining said last-mentioned meansagainst movement upon rotation of said shaft.

3. A switch comprising a base having a pair of stationary contacts secured thereon, a movable contact to engage the stationary contacts, a rotary shaft to operate the movable contact, and means loosely supported by the shaft and engageable with cam surfaces on said shaft to bias the shaft against movement from neutral position, and to bias the shaft to contact engaging position after a predetermined movement from neutral position and means for restraining said last-mentioned means against movement with said shaft,

4. A switch comprising a base having a pair of stationary contacts secured thereon, a movable contact to engage the stationary contacts,-

for restraining rotation of said shaft.

5. A switch comprising a base having a pair of ceases in the base to enjoy free adjustability while being restrained against rotation.

6. A switch comprising a base having a pair of stationary contacts secured thereon, a movable contact to engage the stationary contacts,

7. A switch comprising two stationery spaced pairs of spaced contacts, a bridging contact, a rotatable member pivotally supporting the bridgelement having adjacent angularly related surfaces mounted on and transversely of the rotatable element, a leaf spring disposed to engage and press against one surface of said element in CLARENCE E. GARY.

Images