US3902033A

US3902033A - Momentary switch

Info

Publication number: US3902033A
Application number: US509799A
Authority: US
Inventors: Wesley C Jones
Original assignee: Cherry Electrical Products Corp
Current assignee: Cherry Corp
Priority date: 1974-09-27
Filing date: 1974-09-27
Publication date: 1975-08-26
Anticipated expiration: 1992-08-26

Abstract

A momentary pulse switch embodied in a housing within which an actuator is adapted to be reciprocally moved, with the actuator providing a counterweighted trip lever pivotally connected to and movable therewith into and out of switch actuating position.

Description

United States Patent Jones Au 26 1975 [541 MOMENTARY SWITCH 3,492,882 2/1970 Anderson .0 200/160 x 3,671,700 6 972 M [75} Inventor: Wes?! wlukcgam 3,739,127 6/1973 L411; et a1 200/288 x Assigncel g i ff i f f FOREIGN PATENTS OR APPLICATIONS 619,936 3/1949 United Kingdom 200 100 [22] Filed: Sept. 27, 1974 2H AppL Nu: 509,799 Fri nary li aniir 'rRol:)ert K. Schztefer ASSlSltUII Examiner-William J. Smith Attorney, Agent, or Firm-Edward C. Threedy [52] U.S. Cl. 200/160 [51} Int. C1. H0111 13/50 s7 ABQTRACT [58] Field of Search 200/160, 159 R, 159 A, l

200/67 73 A momentary pulse switch embodied in a housing within which an actuator is adapted to be reciprocally [56] References Cited moved, with the actuator providing a counterweighted UNITED STATES PATENTS tr p lever plvotally con ected to and me able therewith Into and out of switch actuating position. 2,919,333 12/1959 Scholin et all. 200/160 3,281,565 10/1966 Grady ct a1, 200/160 X 4 Claims, 6 Drawing Figures MOMENTARY SWITCH SUMMARY OF THE INVENTION An electrical switch used in association with keyboard type assemblies. The present invention is an improvement over the switch structure shown, described and claimed in the assignees U.S. letters Pat. No. 3,739,127.

The switch structure of the present invention includes a housing for the switch components that comprise a fixed contact terminal and a contact-bearing switch blade normally biased away from the fixed contact terminal. An actuator is adapted to be reciprocally moved within the housing and provides a trip lever for engaging and momentarily flexing the switch blade against its bias and into contact with the fixed contact terminal. The trip lever is pivoted to the actuator and provides a counterweight that functions to return the trip lever to its original position relative to the actuator and the switch blade after it has been returned to a rest position out of engagement with the switch blade.

The invention will be best understood by reference to the accompanying drawings showing the preferred embodiment of the invention, and in which:

FIG. 1 is an elevational view complete the comlete switch of the present invention;

FIG. 2 is an enlarged fragmentary sectional view showing the switch components in their rest or inoperative position;

FIG. 3 is a fragmentary detail sectional view similar to FIG. 2, but showing the switch components in their operative position;

FIGS. 4 and 5 are fragmentary detail sectional views showing the position of the switch components during overtravel of the actuator; and

FIG. 6 is a fragmentary detail sectional view showing the components in relation to one another during the return movement of the switch actuator to its rest or inoperative position.

The complete switch structure 10 is shown in FIG. 1 and, as such, includes a dielectric molded casing 11 which is carried by an enlarged circular snap-in body portion 12 that provides a circumferential peripheral rib 13 which functions to hold the switch structure 10 in its related position on a switch board (not shown).

The switch structure 10 includes

terminals

14 and 15 depending from the body portion 12, as well as a switch button 16 which extends vertically from the casing 11 and which may be, as shown in the drawings, encased in a collapsible protective bellows-type boot 17. The switch structure 10 provides within the casing 11 a fixed terminal 18 which is integral with the terminal 15 and which provides at its upper end a contact 19. Normally spaced from the fixed terminal 18 is a contact bearing switch blade 20 connected to the inner end 21 of the external terminal 14. The switch blade 20 is normally biased away from the fixed terminal 18 in such manner that its contact 22 is normally spaced laterally with respect to the contact 19 of the fixed terminal 18. The switch blade 20 provides at one side thereof an arm 23 which is semicircular in cross section, with the extreme radius extending away from the normal plane of the switch blade 20, as shown.

The switch button 16 is carried by an elongated actuator plunger 24 which is adapted to be freely journaled through an opening 25 formed in the top wall 26 of the casing 11. To one side of the plunger 24 is pivotally mounted a trip lever 27. By a pivot pin 28 the trip lever is pivotally mounted to the plunger 24 and is thereby movable reciprocally therewith within the casing 11.

The trip lever 27 is formed to provide an extension 29 which is adapted to project beyond one longitudinal edge of the plunger 24 in the direction of the switch blade 20. This extension is of such length that it normally projects beyond the longitudinal edge of the switch blade 20, as shown. The extension 29 provides a lower inclined surface 30 which, when the trip lever 27 is moved in a downward direction by cooperative movement of the plunger 24, as shown in FIGS. 3 through 5, will engage the semicircular arm 23 of the switch blade 20. As further downward movement of the plunger 24 and trip lever 27 continues, the engagement between the lever 27 and semicircular arm 23 will cause the switch blade 20 to be flexed against its bias such that its contact 22 will engage the contact 19 of the fixed terminal 18. I

By further downward movement of the plunger 24 and trip lever 27, the semicircular arm 23 will pass off the inclined surface 30 and face edge of the extension 29 onto an upper inclined surface 31, such that the switch blade 20 may then return under the force of its bias to its original position such as shown in FIGS. 4 and 5. The continued movement of the plunger 24 until it is arrested, produces no material switching actuation and is not detrimental to the components of the switch structure.

Referring to FIG. 6, when the plunger 24 together with the trip lever 27 moves in an opposite direction, the semicircular arm 23 will engage the upper inclined surface 31 of the trip lever 27 and will offer sufficient resistance to the continued upward movement of the trip lever 27 so as to cause it to pivot about the pin 28 into the position shown. Continued upward movement of the plunger 24 will cause the extension 29 of the trip lever 27 to pass over the semicircular arm 23 of the switch blade 20 without overcoming the spring contact bias so as to not flex the switch blade into a switchmaking position.

When the trip lever 27 has completely passed over the semicircular arm 23 during its upward movement, it will return to its normal position under the pivotal force of a counterweight 32. As shown, the counterweight 32 is carried by the lowermost corner of the trip lever 27 and extends rearwardly of the confronting longitudinal edge of the plunger 24. The counterweight 32 performs two functions: the one mentioned above, as well as to maintain the trip lever 27 in its normal or rest position, as shown in FIG. 2, by resisting further counterclockwise pivotal movement of the lever 27 about its pin 28 by engaging the rear longitudinal edge of the plunger 24.

After the actuating force has been removed from the switch button 16, the actuator plunger 24 together with the trip lever 27 will be caused to move upwardly within the casing 11 so as to return to normal or rest position by the normal permanent characteristics of the expandable boot 17. In instances where it is required that additional return force is needed, a normal expandable coil spring may be interposed between the bottom surface of the plunger 24 and the bottom wall of the casing 11, in a manner well known in the art.

While I have illustrated and described the preferred form of construction for carrying my invention into effect, this is capable of variation and modification without departing from the spirit of the invention. I, therefore, do not wish to be limited to the precise details of construction set forth, but desire to avail myself of such variations and modifications as come within the scope of the appended claims.

Having thus described my invention, what l claim as new and desire to protect by letters patent is:

l. A momentary push button electrical switch having a housing for the switch components comprising a. a fixed contact-bearing terminal and a springbiased contact-bearing switch blade extending in spaced parallel relation within the housing,

b. an elongated actuator having a portion disposed within the housing and adapted to be reciprocally moved therein,

c. a switch blade trip lever carried by said actuator and having end portions extending beyond opposite longitudinal edges of said actuator and reciprocally movable in a linear path therewith within the housing,

d. means pivotally connecting said trip lever to said actuator with said end portions thereof normally extending beyond opposite longitudinal edges of said actuator, v

e. means on the switch blade and spaced beyond one longitudinal edge of said actuator and in the path of movement of one end portion of said trip lever so as to be spring-biased into contact with said fixed contact-bearing terminal during continuous linear movement in one direction of said trip lever by said actuator,

i. means on said one end portion of said trip lever contacting said means on said switch blade when said trip lever is moved in an opposite linear direction by said actuator so as to pivot said trip lever in a direction opposite to the linear movement of said trip lever without spring-biasing said switch blade out of its spaced relation with said fixed terminal, and

g. means on the other end portion of said trip lever for pivoting said trip lever in an opposite direction after said one end portion of said trip lever has passed beyond said means on said switch blade.

2. A momentary push button electrical switch as defined by claim 1, wherein said means on said switch blade comprises a semicircular arm curved in the direction of said actuator and in the path of movement of said one end portion of said trip lever as it moves reciprocally within the housing. a

3. A momentary push button electrical switch as defined by claim I, wherein said means on said other end portion of said trip lever comprises a counterweight positioned beyond one longitudinal edge of said actuator and normally below the point of pivotal connection between said trip lever and said actuator so as to pivotally maintain said trip lever so that its end portions extend beyond the opposite longitudinal edges of said actuator.

4. A momentary push button electrical switch as defined by claim 3, wherein said means on said switch blade comprises a semicircular arm curved in the direction of said actuator and in the path of movement of said one end portion of said trip lever as it moves reciprocally within the housing.

Claims

1. A momentary push button eLectrical switch having a housing for the switch components comprising a. a fixed contact-bearing terminal and a spring-biased contactbearing switch blade extending in spaced parallel relation within the housing, b. an elongated actuator having a portion disposed within the housing and adapted to be reciprocally moved therein, c. a switch blade trip lever carried by said actuator and having end portions extending beyond opposite longitudinal edges of said actuator and reciprocally movable in a linear path therewith within the housing, d. means pivotally connecting said trip lever to said actuator with said end portions thereof normally extending beyond opposite longitudinal edges of said actuator, e. means on the switch blade and spaced beyond one longitudinal edge of said actuator and in the path of movement of one end portion of said trip lever so as to be spring-biased into contact with said fixed contact-bearing terminal during continuous linear movement in one direction of said trip lever by said actuator, f. means on said one end portion of said trip lever contacting said means on said switch blade when said trip lever is moved in an opposite linear direction by said actuator so as to pivot said trip lever in a direction opposite to the linear movement of said trip lever without spring-biasing said switch blade out of its spaced relation with said fixed terminal, and g. means on the other end portion of said trip lever for pivoting said trip lever in an opposite direction after said one end portion of said trip lever has passed beyond said means on said switch blade.

2. A momentary push button electrical switch as defined by claim 1, wherein said means on said switch blade comprises a semicircular arm curved in the direction of said actuator and in the path of movement of said one end portion of said trip lever as it moves reciprocally within the housing.

3. A momentary push button electrical switch as defined by claim 1, wherein said means on said other end portion of said trip lever comprises a counterweight positioned beyond one longitudinal edge of said actuator and normally below the point of pivotal connection between said trip lever and said actuator so as to pivotally maintain said trip lever so that its end portions extend beyond the opposite longitudinal edges of said actuator.