US3643199A

US3643199A - Pull-push switch with a variable resistor

Info

Publication number: US3643199A
Application number: US63761A
Authority: US
Inventors: Heiroku Tanaka
Original assignee: Matsushita Electric Industrial Co Ltd
Current assignee: Panasonic Holdings Corp
Priority date: 1970-08-14
Filing date: 1970-08-14
Publication date: 1972-02-15
Anticipated expiration: 1989-02-15

Abstract

A pull-push switch with a variable resistor in which on one side of a cap-shaped resistor cover is installed a resistor baseplate or an insulating baseplate mounted with a resistor thereon and on the other side thereof is installed an L-shaped metal plate, a bearing mounted on said resistor baseplate supporting a rotary shaft which is movable through said bearing, one end of said rotary shaft being projected through one side of said resistor cover and through a flat portion of said metal plate adjacent to said resistor cover, a switch being installed on the underside of the other portion of said metal plate which is in turn situated under said rotary shaft, an almost channel-shaped synthetic resin switch driver unit being placed on said other portion of said metal plate, a protrusion for operating said switch being fitted into a hole cut in the trunk of said switch driver unit, a couple of U-shaped music wire springs being bridged between said end of said rotary shaft and pockets cut in the inside surfaces of the legs of said switch driver unit opposite to each other.

Description

United States Patent Tanaka 1 Feb. 15,1972

[S4] PULL-PUSH SWITCH WITH A [21] Appl. No.: 63,761

[30] Foreign Application Priority Data Aug. 20, 1969 Japan ..44/803S6 Aug. 20, l969 Japan... .....44/ao357 June 5, 1970 Japan... .....45/5$873 June 5, 1970 Japan... .....4S/55874 June 5, 1970 Japan... .....4S/5S875 June 5, 1970 Japan ..45/55876 June 5, 1970 Japan ..45/55877 June 5, 1970 Japan... .....45/55878 June 5, 1970 Japan... .....45/55879 June 5, 1970 Japan... .....45/55880 June 5, I970 Japan..................................45/5588l June 5, 1970 Japan ..45l55882 [52] US. Cl. ..338/l72, 338/198, 200/67 A [5 I 1 Int. 9/08 [58] FieldofSearch ..338/l72,l91,l98, 200;

200/168 A, 172 A, 67 A [56] References Cited UNITED STATES PATENTS 3,413,43l l H1968 Bang .338/200 X 3.023.388 2/1962 Girolamo et al .338/ l 72 Primary Examiner-Thomas J. Kozma Assistant Examiner-D. A. Tone Attorney-Stevens, Davis, Miller & Mosher [57] ABSTRACT A pull-push switch with a variable resistor in which on one side of a cap-shaped resistor cover is installed a resistor baseplate or an insulating baseplate mounted with a resistor thereon and on the other side thereof is installed an L-shaped metal plate, a bearing mounted on said resistor baseplate supporting a rotary shaft which is movable through said bearing, one end of said rotary shaft being projected through one side of said resistor cover and through a flat portion of said metal plate adjacent to said resistor cover, a switch being installed on the underside of the other portion of said metal plate which is in turn situated under said rotary shaft, an almost channelshaped synthetic resin switch driver unit being placed on said other portion of said metal plate. a protrusion for operating said switch being fitted into a hole cut in the trunk of said switch driver unit, a couple of U-shaped music wire springs being bridged between said end of said rotary shaft and pockets cut in the inside surfaces of the legs of said switch driver unit opposite to each other.

10 Claims, l8 Drawing Figures PATENTEBFEB 1 5 I872 SHEET 4 0F 7 mom NOW ONN PATENTEU EB 1 5 I972 SHEET 7 BF 7 FIG. l5

PULL-PUSH SWITCH WITH A VARIABLE RESISTOR This invention relates to a pull-push switch equipped with a variable resistor.

An object of the present invention is to provide a pull-push switch with a variable resistor in which on one side of a capshaped resistor cover is installed a resistor baseplate or an insulating baseplate mounted with a resistor thereon and on the other side thereof is installed an L-shaped metal plate, a bearing mounted on said resistor baseplate supporting a rotary shaft which is movable through said bearing, one end of said rotary shaft being projected through one side of said resistor cover and through a flat portion of said metal plate adjacent to said resistor cover, a switch being installed on the underside of the other portion of said metal plate which is in turn situated under said rotary shaft, an almost channel-shaped synthetic resin switch driver unit being placed on said other portion of said metal plate, a protrusion for operating said switch being fitted into a hole cut in the trunk of said switch driver unit, a couple of U-shaped music wire springs being bridged between said end of said rotary shaft and pockets cut in the inside surfaces of the legs of said switch driver unit opposite to each other.

According to the present invention, the action of a couple of U-shaped music wire springs permit the switch driver unit to operate properly, thereby cause the switch to reliably function with a snap action. In addition, the construction of the device is so simple that it can be manufactured at a very low cost.

Another advantage of the present invention is that those portions of the switch which are in motion in a changeover operation are under a simple and low-cost protective cover, assuring an always stable switching operation. Also, since the protective cover is kept pressed against a portion of the fitting metal plate, the switch setup is not loosened nor otherwise adversely affected by vibrations due to the sound from a speaker even if the switch is installed near such a speaker, enhancing the practical value of the switching device.

The above and other objects, features and advantages will be made apparent by the detailed description taken in conjunction with the accompanying drawings, in which:

FIG. I shows a plan of the pull-push switch with a variable resistor embodying the present invention;

FIG. 2 is a perspective view of the above-mentioned embodiment',

FIG. 3 is a perspective view of the essential parts of the same embodiment in a pulled state;

FIG. 4 is an explanatory drawing showing a section of the essential parts of the device;

FIGS. 5 and 6 are sectional views showing guiding grooves;

FIG. '7 is a perspective view of the disjointed essential parts of another embodiment of the pull-push switch with a variable resistor according to the present invention;

FIG. 8 is a front view of the essential parts of the switch shown in FIG. 7;

FIG. 9 is a plan of a third embodiment of the pull-push switch according to the present invention;

FIG. I is a perspective view of the metal plate used for the switch shown in FIG. 9',

FIG. II is a plan of a still another embodiment of the present invention with its protective cover removed;

FIG. I2 is a partially exploded view of the protective cover for the switch shown in FIG. II;

FIGS. I3a, 13b and I30 are respectively front, side and rear views of the protective cover shown in FIG. 12',

FIG. I4 shows a sectional view of a still another embodiment of the present invention;

FIG. I is an enlarged perspective view of a switching driver unit for the switch shown in FIG. 14; and

FIG. I6 is a partially exploded view of the protective cover of the switch shown in FIG. 14.

First, explanation will be made of the first embodiment with reference to FIGS. I to 3. In the figures, the numeral I shows a cap-shaped metal cover for the variable resistor, on the open side of which is installed by means of toes 3 a resistor baseplate 2 coated with a resistance material (not shown in the drawing) on the surface thereof or an insulating baseplate mounted with a resistor thereon. The numeral 4 shows a hearing located at the center of a side of the resistor baseplate 2, the numeral 5 a rotary shaft supported by said bearing 4, the end 6 of said rotary shalt being projected outside of said cover 2. This rotary shaft 5 is movable through said bearing 4 and on the periphery of said rotary shaft inside of the resistor cover I is mounted a brush carrier for holding a brush (not shown) which slides on said resistor. At the end 6 of the rotary shaft 5 is a holder 7 with a cavity at its center. The numeral 8 is an L- shaped metal plate with its semicircular portion attached to one side of the resistor cover I. The end 6 of the rotary shaft 5 is protruded from near the center of said semicircular portion of the metal plate. Under the other portion of the metal plate is a slide switch 9. A protrusion I0 for conducting a switching operation of the switch 9 is projected above said other portion of the metal plate 8 through a guide slot II. The numeral I2 shows a channel-shaped switch driver unit made of a synthetic resin and placed on said other portion of the metal plate. The lower sides of the two legs of the switching driver unit are projected to the underside of the metal plate 8 through guide apertures 13 respectively. The switching driver unit 12, guided by the guide apertures I3, is movable in the direction of the axis of the rotary shaft 5. At the center of the trunk of said switching driver unit is a hole I4 in which is fitted the protrusion 10 of the switch 9. In the shoes of the legs of the switching driver unit are pockets I5 or pits opposite to each other. Between the pockets I5 and the center cavity of the holder 7 on the end 6 of the rotary shaft 5 is bridged a couple of U- shaped music wire springs. The numeral I7 shows an elastic protective cover made of synthetic resin or metal and semicircular in section, and at the lower ends of both sides there are guide grooves I8 to be engaged with the edges of said other portion of the metal plate. At the right end of the metal plate are the positioning protrusions 19 where the metal plate is wider so that the protective cover I7 which, utilizing its elasticity, is fitted to the metal plate 8 is prevented from slipping out.

Now, let us explain the operation of the switch. When as shown in FIG. 2 the rotary shaft is pushed rightward, the end 6 is projected through said semicircular portion of the metal plate 8, while the legs of the switching driver unit are maintained attached to the semicircular portion of the metal plate due to the music wire springs I6. Under this condition, the protrusion I0, guided by the slot 11, is positioned lower to turn the slide switch 9 on (or off a the case may be). Secondly, when the rotary shaft is pulled leftward, the holder 7 on the end of the rotary shaft 5 comes into contact with the semicircular portion of the metal plate 8. At the same time, the switching driver unit, guided by the guide apertures 13, moves rightward due to the action of the music wire springs I6 as shown in FIG. 3 and the protrusion I0 is guided rightward by the slot II, thereby turning the slide switch 9 off (or on as the case may be). When the rotary shaft is pushed rightward again, the switch is restored to the original state as shown in FIG. 2.

As to the operation of the variable resistor, the resistance value can be determined by the same method as the conventional device, in which as the rotary shaft is rotated the brush slides on the resistor attached on the baseplate 2. Instead of installing the holder 7 as in the above embodiment at the edge of the rotary shaft, the edge 6 of the rotary shaft 5 may be formed in such a shape as to hold the ends of the music wire springs.

The U-shaped music wire springs 16 may be formed in such shapes as shown in FIG. 4, in which one end portion of each spring being engaged with the holder, is bent towards the outside so as to form a circular portion. Such U-shaped music wire springs are more reliably engaged with the holder, since the holder are fitted into the circular portion.

FIGS. 5 and 6 show sections of different typed guide grooves. A guide groove having a U-shaped section as shown IIIIII'J'I nnru in H0. 5 is engaged with the sharp edges of the other flat portion of the metal plate in such a manner that the sidewalls of the slot are intruded with the both edges respectively. Another guide groove having a section being progressively narrower towards the bottom as shown in FIG. 6 also has the same effect as the guide groove in FIG. 5, which causes the engagement to be more reliable due to the frictions therebetween.

The entry side of each guide groove, that is the side from which the positioning protrusion is inserted in assembling, may be fonned to be provided with a taper portion so as to widen the space between both the guide grooves, widi a result that the protective cover can be more smoothly mounted to the metal plate.

Another embodiment of the present invention includes, as shown in FIGS. 7 and 8, an improvement on the portions of the protective cover which are to be fitted to the metal plate. 1n this embodiment, the radius of the semicircular portion of the L-shaped metal plate 108 which is attached on the left side of the resistor cover 101 is made smaller than the inside radius of the protective cover 117 so that the metal plate 108 is engaged with the inside surface of the protective cover 117. Further.

protrusions

121 and 122 are newly provided on the inside surface of the protective cover 117 to be engaged with the

indents

123 and 124 formed in the edge of the semicircular portion of the metal plate 108. The protrusion 121 is usually positioned between the two U-shaped springs (not shown) in such a manner to hold them in place.

In this construction, even if an abnormal pressure is applied from outside, the inside edge of the protective cover is supported by the periphery of the semicircular portion of the metal plate 108, thereby preventing the protective cover 117 from being badly deformed. This also prevents the U-shaped music wire springs 116 from being detached from the holder 107 or the switching driver unit 112. The same purpose can be achieved without the

indents

123 and 124 if the

protrusions

121 and 122 on the protective cover 117 are cut partially at the end portions thereof to be fitted into the indents by the thickness of said semicircular portion of said metal plate.

Referring to F168. 9 and 10, a plurality of hooks 220 are provided on the periphery of the semicircular portion of the metal plate 208 adjacent to the left side of the resistor cover 202, which hooks hold the outer surface of the protective cover 217. Hence, under an abnormal external pressure, guide grooves (not shown) and the hooks 220 combine to prevent the protective cover 217 from being extraordinarily deformed. As a result, the U-shaped music wire springs (not shown) are not detached from the switching driver unit (not shown) and from the holder (not shown). Instead of the plurality of the hooks, a band may be provided on the entire periphery of the semicircular portion of the metal plate 208 to be coupled with the periphery of the protective cover 21'].

F168. 11 to 13a, 13b and 130 show a third embodiment of the present invention. The protective cover 317 is mounted on the horizontal portion of the metal plate 308 by means of the guide grooves 318, the lower end of the horizontal portion of the metal plate 308 being provided with protrusions 319, as in the previous embodiment, to prevent the protective cover from slipping out. The feature of this embodiment is that tapered portions 320 are provided on both sides of the metal plate just next to said protrusions 319 on which the ends of the guide grooves 318 of the protective cover are preset to be positioned. Consequently, the protective cover 317, made of an elastic material and with the distance between its grooves 318 smaller than the width of said tapered portion of the metal plate 308, exerts pressure against both sides of the horizontal portion of the metal plate 308 in the directions shown by the arrows A and A, with the result that the whole protective cover is pushed in the direction of arrow B. The protective cover 317 is thus firmly attached to the metal plate 308 and is never loosened under the normal condition.

Still another embodiment of the present invention will be explained with reference to FIGS. 14 to 17. This embodiment has the feature that a boardlike protrusion 420 is suspended from the central ceiling of the protective cover 417 in such a manner that its lower end comes near the upper surface of the central trunk of the switching driver unit 4121 1n FIG. 14, the numeral 421 shows guide protrusions provided on the lower surface of the legs of the switching driver unit 412 in such a manner as to be projected down through the guide apertures 413 cut in said other portion of the metal plate 408.

Because of this construction, the boardlike protrusion 420 blocks any motion of the switching driver unit 412 to float up away from the surface of said other portion of the metal plate, thereby preventing the guide protrusions 421 of the switching driver unit 412 from being detached from the guide apertures 413 of the metal plate. Hence an always stable motion of the switching driver unit on the metal plate 408. This contributes to the correct operation of the slide switch 409.

What is claimed is:

l. A pull-push switch with a variable resistor in which an L- shaped metal plate is installed on one side of a cap-shaped cover for said variable resistor, a resistor baseplate or an insulating baseplate mounted with a resistor thereon being attached to the other side thereof; a bearing is mounted on said resistor baseplate to support a rotary shaft in such a manner that said rotary shaft is movable through said bearing, an end of said rotary shaft being projected through said other side of said cover for said variable resistor and through a flat portion of said metal plate attached to said other side of said cover; a switch is installed on that side of the other flat portion of said metal plate which is opposite to the side of said rotary shaft; 21 channel-shaped switching driver unit made of synthetic resin is placed on said other flat portion of said metal plate; a protrusion for operating said switch is fitted into a hole cut in the trunk of said switching driver unit; and a couple of U- shaped music wire springs are bridged between holding pockets formed inside of opposing legs of said switching driver unit and said end of said rotary shaft, in which an elastic hol' low cover made of synthetic resin and with a semicircular section for protecting said switch is installed on said other flat portion of said metal plate to cover said switching driver unit, and positioning protrusions are formed on both sides of said other flat portion of said metal plate to prevent said protective cover from being removed.

2. A pull-push switch with a variable resistor according to claim 1, in which protrusions which are provided on the inside edges next to guide grooves of said protective cover are positioned adjacent to the legs of said switching driver unit.

3. A pull-push switch with a variable resistor according to claim 1, in which a boardlike protrusion is suspended from the central ceiling of said protective cover. the lower end of said protrusion coming down near the upper surface of the trunk of said switching driver unit.

4. A pull-push switch with a variable resistor according to claim 1, in which said elastic hollow cover is installed on the edges of the other flat portion of said metal plate by means of guide grooves provided on the lower ends of said protective cover, said positioning protrusions are formed on both edges of the other flat portion of said metal plate; each entry side of said guide grooves on the protective cover is formed with a taper portion which gradually widen the distance between said guide grooves, both edges of said positioning protrusions on said metal plate are respectively provided with taper portions being closer to each other towards the end of said metal plate.

5. A pull-push switch with a variable resistor according to claim 1, in which a boardlike protrusion is formed on the inner side of said protective cover along with the central axial direction, and a couple of said wire springs are installed so as to be adjacent to each other not to interfere with each other.

6. A pull-push switch with a variable resistor according to claim 1, in which said positioning protrusions are provided on both sides of said other flat portion of said metal plate to prevent said protective cover from slipping off the radius of a semicircular portion of said metal plate being made a little smaller than the inside radius of said protective cover so that the inside surface of said protective cover is engaged with said semicircular portion of said metal plate.

7. A pull-push switch with a variable resistor according to claim 1, in which said elastic hollow cover is installed on said other flat portion of said metal plate by means of guide grooves cut in the lower ends of said protective cover opposite to each other, said protective cover incasing said switching driver unit, and said positioning protrusions are provided on both sides of said other flat portion of said metal plate to prevent said protective cover from slipping off, a plurality of hooks being provided on the periphery of said flat portion of said metal plate or a band being provided on the entire periphery thereof, which hooks or band is engaged with the periphery of said protective cover.

8. A pull-push switch with a variable resistor according to claim I, in which those sides of said other flat portion of said metal plate which are adjacent to said positioning protrusions are provided with a taper in such a manner that the ends of said guide grooves of said protective cover which are farther from said resistor cover are positioned on said tapered portions of said metal plate.

9. A pull-push switch with a variable resistor according to claim 1, in which said hollow elastic cover is provided with guide grooves at the lower insides thereof, each of said grooves having a U-shaped section or a section being progressively narrower towards the bottom, both edges of said other flat portion of said metal plate being intrudingly engaged with said guide grooves, said protective cover being installed on said other portion of said metal plate in such a manner as to cover said switching driver unit, both sides of said other flat portion of said metal plate having positioning protrusions to prevent said protective cover from slipping off.

10. A pull-push switch with a variable resistor according to claim 1, in which said other flat portion of said metal plate is provided with narrow and long guide apertures into which are fitted straight narrow protrusions located on the underside of the legs of said switching driver unit in such a manner that said switching driver unit can move along said guide apertures.

Claims

1. A pull-push switch with a variable resistor in which an Lshaped metal plate is installed on one side of a cap-shaped cover for said variable resistor, a resistor baseplate or an insulating baseplate mounted with a resistor thereon being attached to the other side thereof; a bearing is mounted on said resistor baseplate to support a rotary shaft in such a manner that said rotary shaft is movable through said bearing, an end of said rotary shaFt being projected through said other side of said cover for said variable resistor and through a flat portion of said metal plate attached to said other side of said cover; a switch is installed on that side of the other flat portion of said metal plate which is opposite to the side of said rotary shaft; a channel-shaped switching driver unit made of synthetic resin is placed on said other flat portion of said metal plate; a protrusion for operating said switch is fitted into a hole cut in the trunk of said switching driver unit; and a couple of U-shaped music wire springs are bridged between holding pockets formed inside of opposing legs of said switching driver unit and said end of said rotary shaft, in which an elastic hollow cover made of synthetic resin and with a semicircular section for protecting said switch is installed on said other flat portion of said metal plate to cover said switching driver unit, and positioning protrusions are formed on both sides of said other flat portion of said metal plate to prevent said protective cover from being removed.

3. A pull-push switch with a variable resistor according to claim 1, in which a boardlike protrusion is suspended from the central ceiling of said protective cover, the lower end of said protrusion coming down near the upper surface of the trunk of said switching driver unit.

4. A pull-push switch with a variable resistor according to claim 1, in which said elastic hollow cover is installed on the edges of the other flat portion of said metal plate by means of guide grooves provided on the lower ends of said protective cover; said positioning protrusions are formed on both edges of the other flat portion of said metal plate; each entry side of said guide grooves on the protective cover is formed with a taper portion which gradually widen the distance between said guide grooves, both edges of said positioning protrusions on said metal plate are respectively provided with taper portions being closer to each other towards the end of said metal plate.

6. A pull-push switch with a variable resistor according to claim 1, in which said positioning protrusions are provided on both sides of said other flat portion of said metal plate to prevent said protective cover from slipping off, the radius of a semicircular portion of said metal plate being made a little smaller than the inside radius of said protective cover so that the inside surface of said protective cover is engaged with said semicircular portion of said metal plate.

8. A pull-push switch with a variable resistor according to claim 1, in which those sides of said other flat portion of said metal plate which are adjacent to said positioning protrusions are provided with a taper in such a manner that the enDs of said guide grooves of said protective cover which are farther from said resistor cover are positioned on said tapered portions of said metal plate.