US2517392A - Electric switch - Google Patents

Description

1950 w. J. ETTINGER 2,517,392

ELECTRIC SWITCH Filed March 10, 1948 INVENT-OR. Wallace J. Eflinger Attys.

Patented Aug. 1, 1950 UNITED ELECTRIC SWITCH Wallace J. Ettinger, Chicago, Ill., assignor to Hotpoint Inc., a corporation of New York Application March 10, 1948, Serial No. 14,107

therebetween and the consequent damage thereto, as well as improper operation of the appliance.

Accordingly, it is a general object of the present invention to provide an electric switch incorporating improved contact structure that is not subject to chatter in the closed position even though considerable vibration is transmitted to the switch through its mounting.

Another object of the invention is to provide in an electric switch of the character noted, im-

proved contact structure in which floating contact or engagement is maintained between the contact members.

Further features of the invention pertain to the particular arrangement of the elements of the electric switch, whereby the above-outlined and additional operating features thereof are attained.

The invention, both as to its organization and method of operation, together with further objects and advantages thereof, will best be understood by reference to the following specification taken in connection with the accompanying drawing, in which Figure l is a fragmentary side view of an electric switch and its associated mounting embodying the present invention; Fig. 2 is a bottom view of the switch, as shown in Fig. 1, illustrating the open circuit position thereof; Fig. 3 is a fragmentary bottom view of the switch, similar to Fig. 2, illustrating the closed circuit position thereof; and Fig. 4 is a fragmentary end view of the switch, as shown in Fig. 1.

Referring now to the drawing, the electric switch In there illustrated and embodying the features of the present invention, comprises a base II provided with an upwardly directed flange I2 that is carried by an associated support I3, the flange I2 being secured directly to the support I'3 by two screws I4 provided with cooperating nuts I5. The base I I may be formed of sheet steel, or the like, and the right-hand side thereof is provided with upper and lower substantially parallel spaced apart outwardly extending arms I6 and II that are forwardly offset to provide supporting surfaces for a platform I8 made of a suitable sheet of insulating material. The platform I8 is disposed slightly forwardly with respect to the base I I and is rigidly secured in place upon the arms is and H by four rivets I9. The platform I8 carries upper and lower substantially identical contact structures and 2 I, each including a pair of resilient contact springs formed of a suitable copper alloy.

Specifically, the contact structure 2I comprises rear and front elongated resilient flexible contact springs 22 and 23 arranged in superimposed spaced-apart relation and carried by the platform I8. More particularly, the contact springs 22 and 23 are provided with fixed ends rigidly secured to the platform I8 and free ends carrying cooperating contact members 24 and 25 respectively. Specifically, a suitable strip of insulating material 26 is arranged on top of the platform I8; a suitable metallic contact terminal 21 is arranged on top of the insulating strip 26; the contact spring 22 is arranged on top of the contact terminal 21; a suitable strip of insulating material 28 is arranged on top of the contact spring 22; a suitable stop or limit spring 29 is arranged on top of the insulating strip 28; a suitable metallic terminal 30 is arranged on top of the stop spring 29; the contact spring 23 is arranged on top of the contact terminal 30; and a suitable strip of insulating material 3I is arranged on top of the contact spring 23. Finally the elements mentioned are retained in stacked relation by two screws 32 extending through aligned openings formed therein and carrying nuts, not shown, disposed below the platform I8. The contact terminal 21 is arranged in good electric contact with the contact spring 22 and extends outwardly in order that it may be connected to one terminal of an associated circuit, not shown; and likewise, the contact terminal 30 is arranged in good electric contact with the contact spring 23 and extends downwardly in order that it may be connected to another terminal of an associated circuit, not shown. Accordingly, the contact springs 22 and 23 are mutually electrically insulated from each other and from the base II; and the stop spring 29 is interposed with respect to the contact springs 22 and 23 and arranged in stacked relation therewith.

The left-hand side of the base II is provided with upper and lower substantially parallel spaced-apart forwardly extending arms 33 and 34 having aligned openings therein through which a pivot pin 35 extends, the upper end of the pivot pin 35 being provided with an enlarged head 36 and the lower end of the pivot pin 35 having an opening therein through which a key 37 is arranged. A bracket 38 provided with upper and lower inwardly extending arms 39 and 40 position.

is pivotally mounted on the pivot pin 35, the pivot pin 55 extending through aligned openings provided in the arms 33 and 49. The inner end of the bracket 38 carries an insulating operating member il secured thereto by two rivets 42; which insulating operating member 4! cooperates with the rear contact spring 22 of the contact structure 2i and also with the corresponding rear contact spring of the contact structure 26. The outer end of the bracket 38 isprovided with other while maintaining floating contact between I the contact members 24 and 25.

a curved operating arm 43 that, in turn, co-

operates with a pivotally mounted lever -54. Also" a resilient steel spring 15 is arranged to surround pin 35, as illustrated in Figs; 1 and 2.. Specifically, the bracket 38' is biased by the spring 45 in orderto move the insulating operating member 4| toward the ibasewtlat; whereby the insulating operating member til engages the rear contact spring 22' moving it'towardthebase i l away from the front contact spring Z3 inorder to move the contact members it and 25 into open circuit More particularly, the. lever 44 is substantially L-shaped being provided with a rearwardly ex;- tending arm 48 that is pivotally' mounted by a pin 59 upon-a torwardlyprojecting arm 55 car- "ried'by the base H Also the lever'4 i is provided with a downwardly extending arm 54 that directly engages the operating arm at of the bracket 38, as well as a forwardly projecting arm 52' carrying an outwardlyextending tab 53 that, in'turn, is adapted to cooperatewith a downwardl y proj ecti'ng tab 54 carried bysacooperating movable support 55'. Specifically, when the 'support 55 is moved downwardly toward the support" IS, the tab 54 carried thereby engages the "tab 53- carried by the lever 44; whereby the lever '44 is pivoted in the 'cl'ockwisedirection as viewed in- Fig. 4 about the pivot pin 49 causing the arm on the lever 44' to engage the operating arm 43 of the bracket '38 in order to pivot the bracket 38 in the counter-clockwise direction, as viewed "in Fig. 2, against the bias or" the spring 415'; where.-

upon the insulating operating member ll disengages the rear contact spring :22 permitting the contact members 2L; and 25110 be moved into 'closed circuit position, as illustrated in Fig. 3.

When the bracket 38 occupies its normal posi- "tion, illustrated in Fig. 2, the contact springs 22 and23 are moved to disengage the contact members 24 and 25; and when the bracket 38 occupies its operated position, illustrated in Fig. 3, the contact springs 22 and 23 are moved to engage the 29, and the insulating operating member 45 cornpletely disengages the outer end of the rear contact spring 22 so that the contact springs 22 and 23 may be moved through limited distances toward and away from the base II with each Subsequently, when the lever 44 is controlled to release the bracket 38 the spring 45 moves the bracket 38 from its operated position, shown in Fig. 3, to its normal position, shown in Fig. 2. Specifically, when movement of the bracket 38 from its operated position to its normal position is initiated, the insulating operating member 4| first engages the outer end of the rear contact spring 22 moving it toward the base I I. The front contact spring 2% follows the initial movement of the rear contact spring 22 toward the base ll since the contact springs 22 and 23 are biased toward each other due to their inherent resiliency. However, after a predetermined limited movement of the-front contact spring 23 with the rear contact spring 22 toward the base H, the outer end of the stop spring 29 engages the associated front spring, 23 arresting further movementthereof. Accordingly, continued movement of the rear spring :22 toward the base H after movement of the front spring :23 has been atrested is efi'ective to movev the contact" members 2 5 ,and25 into disengagement.

Thereafter, when the lever M is controlled to operate the bracket .38, the bracket is moved against the bias of the spring difrom its normal position, shown in Fig. 2, to its operated position, shown in. '3. Specifically, when the movement of the bracket 38 from its normal :position to its operated position is initiated the insulating operating member 41' first "begins to release the'outer end of the rear contact spring 22 permitting it "to move due to itsinherentresiliency away from the base H. The rear contact spring 22 then moves the contact member 24' into engagement with the contact member 2-5, thereby riding the contact spring 23 out of engagement with the associated stop spring 29; whereby the contact springs 22 and -23 "maintain floating engagement between the contact members 24 and 25. I

In the switch ill the identical contact structures 20 and 2! are especially adapted to control the open-ing'and closing of the two outside lines in an Edison three-wire power system employed inel'ectrlc home appliances or the like. The contact structures '28 and 21 in the switch Ill are very advantageous in view of the fact that floating contact maintained between the pairs of contact members carried by the pairs of contact springs "becauseof the balanced forces in the pairs or contact springs in closed positions thereby eliminating chatter between the contact members at this time even though the support it for the switch it is subject to considerable vibration. This floating engagement between the contact members in the contact structures 23 and '2! preventing chatter therebetween eliminates arcing therebetween .and the consequent damage thereto.

Also the arrangement of the bracket 38 cooperating with the contact structures 20 and?! is very admntageous as it positively moves the con tact members to their open circuit positions when the invention, it will be understood that various modifications may be made therein, and it is intended to cover in the appended claim all such modifications as fall within the true spirit and scope of the invention.

What is claimed is:

A switch comprising a longitudinally extending base, two elongated resilient flexible contact springs carried by said base and extending longitudinally thereof, said contact springs being provided with fixed ends rigidly secured to said base and free ends carrying cooperating contacts, said contact springs being arranged in spaced-apart relation and mutually insulated from each other and from said base, said contact springs being biased by their resiliency toward each other in order to engage said contacts, an operating member pivotally mounted intermediate its ends upon a first pin carried by said base and extending transversely thereof for movement between a normal position and an operated position and insulated from said contact springs, one end of said operating member cooperating with one of said contact springs and completely disengaging said one contact spring when said operating member occupies its operated position and engaging said one contact spring when said operating member occupies its normal position, a spring biasing said operating member from its operated position into its normal position, an element pivotally mounted upon a second pin carried by said base and extending longitudinally thereof for independent movement and having an operated position engaging the other end of said operating member in order to restrain said operating member in its operated position against the bias of said spring, said contact springs being free to move in either direction through limited distances with each other when said operating member occupies its operated position in order to maintain floating engagement between said contacts, thereby to absorb any vibratory movement transmitted to said contact springs through said base, said element being movable from its operated position to release said other end of said operating member so that said operating member is moved by said spring from its operated position to its normal position, said one contact spring being moved in a predetermined direction by engagement of said one end of said operating member when said operating member is moved from its operated position to its normal position, said other contact sprin being moved initially in said predetermined direction by its resiiiency with said one contact spring, and a stop carried by said base and arranged to arrest further movement of said other contact spring in said predetermined direction beyond said limited distance, said contacts being disengaged by continued movement of said one contact spring in said predetermined direction after further movement of said other contact spring is arrested.

WALLACE J. ETTINGER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,781,962 Stirling Nov. 18, 1930 1,887,273 Lewis Nov. 8, 1932 2,266,153 Bluemle Dec. 16, 1941 2,427,277 Hasselbaum Sept. 9, 1947

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