US3924220A

US3924220A - Electric switch combined with variable resistor

Info

Publication number: US3924220A
Application number: US475597A
Authority: US
Inventors: Hiroshi Matsui; Hisao Kitahara; Shozo Watanabe
Original assignee: Matsushita Electric Industrial Co Ltd
Current assignee: Panasonic Holdings Corp
Priority date: 1973-06-13
Filing date: 1974-06-03
Publication date: 1975-12-02
Anticipated expiration: 1992-12-02
Also published as: CA993070A; JPS5018976U

Abstract

A pull-push type switch in combination with a variable resistor is disclosed. An operating shaft of a variable resistor extends into a housing for a switch attached to a cover of the variable resistor. A fixed contact holder is attached to one side of the switch housing. Within the switch housing are disposed a movable contact holder and a movable-contact-holder actuating member which are operatively coupled to each other by a U-shaped spring in such a way that when the actuating member is shifted between a first and second positions by the operating shaft the movable contact holder may be shifted in the opposite direction between a first and a second position, thereby bridging between a selected pair of the fixed contacts of the switch. The switch may be opened or closed by the operating shaft at any angular position.

Description

United States Patent 11 1 1111 3,924,220 Matsui et a1. 1 1 Dec. 2, 1975 15 ELECTRIC SWITCH COMBINED WITH 3.350522 10/1967 Olson 200/76 V I IS 3,413,431 11/1968 Bang I 200/330 3.602.868 8/1971 Lybrook 338/198 1 Inventors: Hiroshi M y g Hisao 3,641,292 2/1972 Tanaka.... 200/76 Kitahara, Takatsuki; Shozo $643,199 2/1972 Tanaka 338/172 Watanabe, Moriguchi. all of Japan [73] Assignee: Matsushita Electric Industrial C0., primar-i EmmmwVolodymyr Mzlyewsky Ltd Osaka Japan Attorney, Agent, or FirmBurgess. Ryan and Wayne [22] Filed. June 3, 1974 ABSTRACT [21] Appl 475597 A pull-push type switch in combination with a variable resistor is disclosed. An operating shaft of a variable [30] F i A li ti P i it D resistor extends into a housing for a switch attached to June 13 1973 Japan N 48 70473 a cover of the variable resistor. A fixed contact holder is attached to one side of the switch housing. Within 52 us. c1. 338/172; 200/76; 200/330; the Swhch housing are disphed a movable 10mm 338/198 holder and a movable-contact-holder actuating mem- 511 int. c1. 1101c 9/08 her which are Pemhve|y each other hY 58 Field of Search 338/110, 129, 172, 173, U'ShhPed Spring in Such h why when achmhg 338/179, 191. 198, 200 20]; 200/67 A, member is shifted between a first and second positions 77 330 by the operating shaft the movable contact holder may be shifted in the opposite direction between a first and [56] References Cited :1 second position, thereby bridging between a selected UNITED STATES PATENTS pair of the fixed contacts of the switch. The switch may be opened or closed by the operating shaft at any 2,881,280 4/1959 Barden et a1. 200/77 angular position 3,023,388 2/1962 Di Girolamo-et a1 338/172 3,236,971 2/1966 Cotsworth 338/172 X 1 Claim, 4 Drawing Figures US. Patent Dec. 2, 1975 Sheet 1 of2 3,924,220

U.S. Patent DEC. 2, 1975 Sheet 2 on 3,924,220

FIG. 2

.- 1 ELECTRIC SWITCH COMBINED WITH VARIABLE RESISTOR BACKGROUND OF THE INVENTION The present invention relates generally to a switch combined with a variable resistor and more particularly to a switch combined with a variable resistor of the type in which a switch assembly is attached to the rear of the variable resistor in such a way that the switch may be opened or closed by the operating shaft of the variable resistor.

There have been known various types of switches combined with variable resistors in which one common operating shaft is used for operatng both the switch and the variable resistor. One type of a switch combined with a variable resistor is such that the switch cannot be operated unless the operating shaft rotates the wiper to either of the ends of the resistive element within the variable resistor. Therefore, the operation is inconvenient for practical use. In another type, a contactor or movable contact of a switch is pressed against a pair of fixed contacts under the force of a spring so that the operation is unstable or not reliable. That is, the

. contact between the movable and fixed contacts is not satisfactory, resulting in the burning of the contacts. Therefore, the service life is very short. Furthermore, the conventional switches combined with a variable resistor are complex in construction with many parts and difficult to assemble with the result of the increase in cost.

SUMMARY OF THE INVENTION One of the objects of the present invention is therefore to provide an improved switch combined with a variable resistor which may substantially eliminate such problems and defects as encountered in the above mentioned switches combined with a variable resistor.

Another object of the present invention is to provide an improvedswitch combined with a variable resistor in which the switch may be opened or closed by a common operating shaft at any angular position thereof, and the satisfactory switching action may be insured by a U-shaped spring.

A further object of the present invention is to provide a switch combined with a variable resistor which is simple in construction and assembly and inexpensive to manufacture and is best adapted for use in multiple circuits of various communication equipments, in particular, television receivers.

Briefly stated, according to the present invention, a common operating shaft is used for operating both a switch and a variable resistor. For this purpose, the operating shaft extends into a switch housing attached to the rear of the variable resistor cover so that the switch may be opened or closed as the operating shaft is pushed or pulled. More particularly, within the switch housing are disposed a movable contact holder and a movable-contact-holder actuating member which are operatively coupled to each other by a spring in such a way that when the actuating member is shifted by the operating shaft from one position to the other, the movable contact holder is shifted in the opposite direction under the force of the spring so as to bridge a selected pair of fixed contacts of the switch. The movable contact attached to the movable contact holder is made up of a metallic sheet doubled back upon itself so that the doubled back portions may slidably sandwich the fixed contacts therebetween, thereby insuring the satisfactory electrical contact between the movable and fixed contacts.

The operating shaft is fitted into a center hole of a wiper holder of the variable resistor in such a way that upon rotation of the operating shaft, the wiper holder may rotate in unison with the operating shaft, but when the operating shaft is pushed or pulled, it may slide axially through the center hole of the wiper holder so as to hold the latter stationary. Therefore, the operation of the variable resistor, i.e., the rotation of the operating shaft may be carried out independently of the operation of the switch, and-vice versa.

According to another aspect of the present invention, a plurality of switch contacts may be provided, and a plurality of variable resistors may be ganged. Therefore, a multi-contact switch combined with a ganged variable resistor may be provided which may find a wide application in various fields.

The above and other objects, features and advantages of the present invention will become more apparent from the following description of one preferred embodiment thereof taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view of one preferred embodiment of the present invention with an operating shaft being in the pushed-in or upper position;

FIG. 2 is a left side view ofa movable-contact-holderactuating member (15) of a switch;

FIG. 3 is a right side view thereof; and

FIG.4 is a perspective view illustrating the operative coupling between the actuating member (15) and a movable contact holder (16) by a spring (17).

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, a mount 1 and a shield plate 2 are fitted over a bearing 3 rotatably supporting an operating shaft 5. A horseshoe-shaped resistor member 4 is mounted upon the mount I and has its both ends 'mechanically and electrically connected coupled to outer or end terminals (not shown). The operating shaft 5 is both rotatable and slidable in the bearing 3 for adjusting the resistance of a variable resistor and opening and closing a switch as will be described in more detail hereinafter. The operating shaft 5 extends through an opening 7 formed'at the center of the top of a capshaped cover 6 for the variable resistor which is attached to the mount 1 by bending ears (not shown) of the cap-shaped cover 6 after they are inserted into mating holes (not shown) of the mount 1. A wiper holder 8 is fitted over the operating shaft 5 within a space defined by the mount 1 and the cap-shaped cover 6 so that it may rotate in unison with the operating shaft. A wiper or brush 9 is attached to the undersurface of the wiper holder 8 and is brought into sliding contact with the resistor member 4. The wiper 9 is electrically coupled to a center terminal 11 attached to the mount 1 through a slip ring 22 attached to the wiper 9 and a contactor 10 which is normally electrically coupled to the wiper 9.

A housing 12 for the switch having its one side and its bottom opened is attached to the top of the capshaped cover 6. The upper end of the operating shaft 5 is located within the housing 12. A switch terminal mount 13 attached to one side of the housing 12 has switch terminals or

fixed contacts

14a, 14b and 14c.

Within the housing 12 are disposed a movable contact-holder actuating member 15 and a movable contact holder 16 in transversely spaced apartrelation. A U-shaped spring 17 is loaded between a spring stop 18 attached to the actuating member 15 and a spring stopv 19 attached to the movable contact holder 16 so that the actuating member 15 and the movable contact holder 16 are forced to move away from each other to be pressed against the inner wall of the housing and the terminal mount 13, respectively.

The actuating member 15 has an engaging member 20 formed at the lower end thereof for engagement with the upper end A of the operating shaft 5 so that when the operating shaft 5 is pushed or pulled, the actuating member is pushed upwardly or pulled downwardly within the housing 12.

A movable contact 21 attached to one side of the movable contact holder 16 is adapted to bridge between the

terminals

14a and 14b or 14b and 14c as the movable contact holder 16 is pulled downwardly or pushed upwardly. As shown in FIG. 1, the movable contact 21 comprises an elastic metal sheet doubled back upon itself so as to sandwich the terminals or fixed contacts 14a 14c therebetween, thereby insuring satisfactory electrical contact between the movable contact and the fixed contact.

Next, the mode of operation will be described. FIG. 1 shows the operating shaft 5 in its pushed-in position. The movable-contact-holder actuating member 15 is in the upper or pushed-in position while the movable contact holder 16 is brought to the lower position under the force of the spring 17. As a result, the movable contact 21 bridges between the terminals or fixed

contacts

14a and 14b. When the operating shaft 5 is pulled downwardly, the actuating member 15 is forced to the lower or pulled out position while the movable contact holder 16 is shifted to the upper position under the force of the spring 17 so that the movable contact 21 bridges the terminals or fixed

contacts

14b and 14c while opening the

fixed contacts

14a and 14b.

Upon rotation of the operating shaft 5, the wiper holder 8 is rotated so that the wiper 9 slides over the resistor member 4. Therefore, the resistances between the outer or. end terminals (not shown) and the center terminal may be suitably adjusted. When the operating shaft 5 is rotated, its upper end 5A also rotates in sliding contact with the engaging member of the actuating member 15 so that the mode of the switch remains unchanged.

What is claimed is: 1. An electrical switch combined with a variable resistor, comprising: v

a. a dielectric base,

b. an operating shaft axially slidable and rotatably mounted in the base,

c. a variable resistor mounted in said base and provided with a wiper arm rotatably coupled to the shaft and fixed in the axial direction,

d. a switch cover housing fixed to the base and being provided with at least two internal walls substantially parallel to the shaft axis, one of the two parallel walls of the switch cover housing being provided with stationary switch contacts, e.a dielectric movable contact holder provided with switch contacts and slideably arranged in the switch cover housing abutting said one of said two parallel walls for motion in a direction parallel to said one of said walls, a switch actuating member slideably arranged in said switch cover housing abutting another of said two parallel walls for motion in a direction parallel to said other of said two parallel walls, an end of the operating shaft being rotatably coupled to said switch actuating member and translationally fixed to the switch actuating member for moving said switch actuating member in said switch covered housing in a direction parallel to the operating'shaft axis, and spring means interconnecting said movable contact holder and said switch actuating member for biasing said movable contact holder in a direction opposite to the direction of said axial motion of the shaft and actuating member and for biasing said switch actuating member and said movable contact holder against said wallsabutting said switch actuating member and movable contact holder, whereby said movable contact holder and said switch actuating member move in opposite directions and whereby said switch contacts of said movable contact holder are urged against said fixed switch contacts in a position of said movable contact holder by said spring means, said spring means operatively interconnecting 'said actuating member and said movable contact holder being a U-shaped spring which is adapted to force said actuating member and said movable contact holder to move away from each other.

Claims

1. An electrical switch combined with a variable resistor, comprising: a. a dielectric base, b. an operating shaft axially slidable and rotatably mounted in the base, c. a variable resistor mounted in said base and provided with a wiper arm rotatably coupled to the shaft and fixed in the axial direction, d. a switch cover housing fixed to the base and being provided with at least two internal walls substantially parallel to the shaft axis, one of the two parallel walls of the switch cover housing being provided with stationary switch contacts, e. a dielectric movable contact holder provided with switch contacts and slideably arranged in the switch cover housing abutting said one of said two parallel walls for motion in a direction parallel to said one of said walls, a switch actuating member slideably arranged in said switch cover housing abutting another of said two parallel walls for motion in a direction parallel to said other of said two parallel walls, an end of the operating shaft being rotatably coupled to said switch actuating member and translationally fixed to the switch actuating meMber for moving said switch actuating member in said switch covered housing in a direction parallel to the operating shaft axis, and f. spring means interconnecting said movable contact holder and said switch actuating member for biasing said movable contact holder in a direction opposite to the direction of said axial motion of the shaft and actuating member and for biasing said switch actuating member and said movable contact holder against said walls abutting said switch actuating member and movable contact holder, whereby said movable contact holder and said switch actuating member move in opposite directions and whereby said switch contacts of said movable contact holder are urged against said fixed switch contacts in a position of said movable contact holder by said spring means, said spring means operatively interconnecting said actuating member and said movable contact holder being a U-shaped spring which is adapted to force said actuating member and said movable contact holder to move away from each other.