Multi-Position Electric Switch

1. Field of the Invention

The present invention relates to a switch suitable for use in the remote control of electrically driven rearview mirrors of a motor vehicle.

2. Description of the Prior Art

Each of a pair of electrically driven rearview mirrors mounted on a door, a fender or the like, of a motor vehicle contains two electric motors, etc. in its driving section, said electric motors, etc. being controlled by means of a switch inside the vehicle so as to adjust the direction of inclination, horizontal or vertical, of each mirror. The switch for controlling the electrically driven rearview mirrors is required to have the functions of actuating each of said two electric motors of each mirror independently, and changing the polarity of electric power supply thereto. Also, the switch must be easy to fix in the instrument panel, etc.

To meet such requirements, the inventor has already invented a switch which, as disclosed in Japanese Utility Model Application No. Sho 56-71428, comprises a housing, an operation member disposed within said housing at a certain clearance from the inner walls of said housing, said operation member being adapted to swing from its neutral position in four directions meeting at right angles with one another, two switch elements disposed between said operation member and each of the four inner walls of said housing, each of said switch elements comprising a pair of sheet electrodes and a rubber sheet disposed therebetween which rubber sheet becomes conductive only when and where it is pressed (Such a rubber sheet will hereinafter be referred to as a "pressure conductive rubber sheet".), said switch elements being adapted to change the polarity of electric power supply.

However, the prior art switch has a deep shape and cannot be made small because the operation member is swingably disposed within the housing and the switch elements are disposed between the operation member and the four inner walls of the housing. Also, the switch is not very easy to fix in the instrument panel, etc. Furthermore, it does not give a good feeling of use because the operation member has almost no stroke and does not click at all.

It is therefore an object of the invention to provide a multi-position electrical switch which has obviated all the disadvantages of the prior art.

A switch according to a first embodiment of the invention comprises a housing, an insulating base plate disposed within said housing, a plurality of fixed contact components disposed around a specific center on said insulating base plate, each of said fixed contact components consisting of a pair of printed circuit electrodes, a pressure conductive rubber sheet laid on said fixed contact components, said rubber sheet and said fixed contact components forming switch elements, a plurality of operation buttons disposed over said rubber sheet, each of said operation buttons being given a tendency to return to its original position, each of said operation buttons being provided with pressing surfaces for closing said switch elements and with an engagement piece projecting toward said specific center, a crown-shaped interceptor rotatably disposed in said specific center, said interceptor being provided at its upper side with a jagged cam surface corresponding to said engagement pieces, said jagged cam surface having teeth, the number of which is different from the number of said operation buttons, said interceptor thus being adapted to close certain switch elements when one of said operation buttons is pushed until its engagement piece enters the deepest portion of a concave on said jagged cam surface, thereby preventing other switch elements from being closed at the same time.

A switch according to a second embodiment of the invention comprises a housing, an insulating base plate disposed within said housing, a plurality of fixed contact components which are the same as in the first embodiment, an insulating sheet laid on top of said insulating base plate, said insulating sheet being provided in positions corresponding to the positions of said fixed contact components with cup-shaped elastic portions opening toward said fixed contact components, said elastic portions being respectively provided inside their top with movable contacts, an inclinable operation button having pressing surfaces for closing said switch elements when said operation button is inclined, said operation button being provided in said specific center and in positions corresponding to areas between said elastic portions with projections for preventing the simultaneous closing of said switch elements.

The above-mentioned construction ensures a flat, thin and small switch which can be easily fixed in a relatively small space such as an instrument panel of a motor vehicle. Therefore, the switch according to any of the two embodiments is very suitable for use in the control of rearview mirrors of a motor vehicle.

In addition to the aforesaid common advantages, each of the two embodiments has its own advantages as follows:

According to the first embodiment in which the switch comprises a plurality of operation buttons and an interceptor in the specific center for preventing the simultaneous closing of the switch elements, when the switch is used for controlling the rearview mirrors of a motor vehicle each of the independent operation buttons definitely corresponds to each of the directions (up, down, right and left) in which the angle of the rearview mirrors is adjusted. Therefore, the switch is easy to use and gives a good feeling of use.

According to the second embodiment in which the switch comprises cup-shaped elastic portions disposed over the fixed contact components, said elastic portions being respectively provided inside with movable contacts, and an inclinable operation button having projections for preventing the simultaneous closing of the switch elements, the operation button is inclined against the elastic force of the elastic portions and is returned to its original position thereby. Therefore, the operation button gives a more constant feeling of use and ensures smooth operation even after it is used for a long period of time. Also, the switch is inexpensive because the movable contacts do not have to be made of expensive pressure conductive rubber and even when they are they can be made smaller.

FIGS. 1 to 15 illustrate a first embodiment of the invention.

FIG. 1 is a plan view of a switch.

FIG. 2 is a sectional view taken on line II--II of FIG. 1.

FIG. 3 is a bottom view of a housing.

FIG. 4 is a plan view of a supporting plate seen in FIG. 2.

FIG. 5 is a plan view of an operation button.

FIG. 6 is a view taken in the direction of the arrow Y in FIG. 5.

FIG. 7 is a bottom view of said operation button.

FIG. 8 is an enlarged perspective view of an interceptor seen in FIG. 2.

FIG. 9 is a plan view of said interceptor.

FIG. 10 is a development of the side of said interceptor and also illustrates engagement pieces.

FIG. 11 is a sectional view taken on line XI--XI of FIG. 1.

FIG. 12 is a bottom view of a slide block seen in FIG. 11.

FIG. 13 is an enlarged plan view of an insulating base plate seen in FIG. 2.

FIG. 14 is a plan view schematically illustrating the arrangement of switch elements on said insulating base plate.

FIG. 15 is a circuit diagram showing connections between switch elements, etc.

FIGS. 16 to 21 illustrate a second embodiment of the invention.

FIG. 16 is a plan view of a switch.

FIG. 17 is an enlarged sectional view taken on line XVII--XVII of FIG. 16.

FIG. 18 is a bottom view of an insulating sheet.

FIG. 19 is a bottom view of an operation button.

FIG. 20 is an enlarged plan view of an insulating base plate.

FIG. 21 is a plan view schematically illustrating the arrangement of switch elements on said insulating base plate.

The present invention will now be described in detail, with reference to a first embodiment illustrated in FIGS. 1 to 15 in which the invention is applied to a switch for controlling electrically driven rearview mirrors of a motor vehicle.

Numeral 1 represents a housing. Numeral 2 represents an insulating base plate of a printed circuit, which plate also serves as a bottom plate of the housing 1. Disposed within the housing 1 are a switch S1 for changing the polarity of electric power supply and another switch S2 for the changeover between a right-hand mirror R and a left-hand mirror L.

First, the switch S1 will be described in detail. The switch S1 comprises, for example, eight switch elements A to F' as shown in FIG. 15. Eight pairs of printed circuit electrodes 3a and 4a to 3f' and 4f', serving as fixed contact components of the switch elements A to F', are printed around a specific center 7 on the base plate 2 so that each pair of electrodes are engaged with each other like a pair of combs. The whole printed circuit electrodes 3a and 4a to 3f' and 4f' cover an approximately square area around the specific center 7 on the base plate 2. See FIG. 13.

A pressure conductive rubber sheet 5, corresponding to a movable contact of a conventional switch element, is laid on said fixed contact components. The single rubber sheet 5 is common to all the fixed contact components. The pressure conductive rubber sheet 5 is made of silicone rubber and metal particles, for example. It is usually nonconductive and becomes conductive according to the pressure applied thereto.

Thus, according to the present invention, the eight switch elements A to F' are disposed on the surface of the base plate 2 and they are connected by printed conductors 6 so as to form two switch means for changing the polarity of electric power supply. That is, in FIG. 15, the four switch elements A, B, E and F form one switch means (switch means for vertical adjustment) and the four switch elements C, D, E' and F' form the other switch means (switch means for horizontal adjustment). The arrangement of the switch elements A to F' on the base plate 2 is illustrated in FIG. 14.

Driving means as follows are disposed over said switch elements A to F'.

First, a supporting plate 8 as shown in FIG. 4 is disposed on top of the rubber sheet 5. The supporting plate 8 is fixed at its periphery to the housing 1. The supporting plate 8 is provided at its portions corresponding to the positions of said switch elements A to F' with openings 8a into which pressing surfaces (described later) are loosely inserted. The housing 1 is provided at its portion corresponding to said specific center 7 on the inside with a projecting axial pin 1e as shown in FIG. 3, said housing 1 further having four trapezoid openings 1a to 1d disposed with the axial pin 1e as the center of symmetry. Operation buttons 11 to 14 are respectively inserted into the trapezoid openings 1a to 1d so that each of the operation buttons can be pushed in and automatically returns to its original position. Each of the operation buttons 11 to 14 is provided on its side facing the rubber sheet S with two pressing surfaces which project slightly. FIGS. 6 and 7 show two pressing surfaces 11a and 11b of the operation button 11 by way of example. The pressing surface 11a corresponds to the switch element A, while the other pressing surface 11b corresponds to the switch element F. The operation button 11 is provided with an engagement piece 11c projecting toward the axial pin 1e, said engagement piece 11c having a triangular section with its vertex facing downward (toward the rubber sheet 5). The operation button 11 further has a spring hole 11d between the two pressing surfaces 11a and 11b. A coiled spring 10 is disposed within the spring hole 11a and is compressed between the operation button 11 and the supporting plate 8 so as to give the operation button 11 a tendency to return to its original position. Usually the pressing surfaces 11a and 11b of the operation button 11 are partially inserted into the openings 8a of the supporting plates 8 so that the pressing surfaces 11a and 11b are surely guided by the openings 8a when the operation button 11 is pushed.

The construction and arrangement of the other operation buttons 12 to 14 are the same as mentioned above. The operation button 12 corresponds to the switch elements B and E. The operation button 13 corresponds to the switch elements F' and C. The operation button 14 corresponds to the switch elements D and E'. In this way, each of the operation buttons 11 to 14 corresponds to two switch elements.

A crown-shaped interceptor 15 having a jagged cam surface 15a corresponding to the engagement pieces 11c to 14c is rotatably attached to the axial pin 1e in the specific center 7. As shown in FIGS. 8 to 10, the jagged cam surface 15a has teeth, the number of which is different from the number (four) of the operation buttons 11 to 14, that is, the number (four) of the engagement pieces 11c to 14c. The number of the teeth of the jagged cam surface 15a is five in the illustrated example, but it is not restricted thereto and may be three, seven, nine or any other number provided that the difference between the number of the teeth and the number of the operation buttons is an odd number. Each of the teeth of the jagged cam surface has a shape resembling a saw tooth, and is not symmetrical. That is, portions on both sides of a point are not the same in shape. In a plan view of FIG. 9, each of the teeth occupies an opening angle of 72.degree., and a portion thereof on one side of the point occupies an opening angle of 30.degree. while a portion thereof on the other side of the point occupies an opening angle of 42.degree..

As shown in FIG. 10, when one engagement piece 11c is in a position corresponding to the deepest portion of a concave, the other engagement pieces 12c to 14c are in positions corresponding to other portions of respective concaves. When any one of the engagement pieces 11c to 14c is pushed into the deepest portion of a concave, only two switch elements corresponding to the operation button pushed are exclusively closed, so that other switch elements are prevented from being closed at the same time.

Reference will now be made to the switch S2 for selectively connecting the above-mentioned switch S1 with either the right-hand mirror R or the left-hand mirror L. The switch S2 comprises two circuits and six contacts. Contact patterns l, m and 16a to 16d, corresponding to the six contacts, are printed near one end (upper portion in FIG. 13) of the base plate 2. A slide block 17, slidable right and left in FIG. 11 or 12, is disposed over the contact patterns l, m and 16a to 16d. The slide block 17 is provided with movable contacts 18a and 18b corresponding to the contact patterns l, m and 16a to 16d. A pair of push buttons 19a and 19b respectively corresponding to the right-hand mirror R and the left-hand mirror L are disposed on both sides of the slide block 17 in the direction of its slide. The driving end of each push button is engaged with each of taper portions 17a and 17b formed on both ends of the slide block 17. Numerals 21a and 21b represent balls for positioning the push buttons 19a and 19b.

Thus, the embodiment illustrated in FIGS. 1 to 15 is a hybrid switch comprising said switch S1 including the eight switch elements A to F' and said changeover switch S2.

Numeral 22 in FIG. 2 represents a connector for connecting the contacts l, m and 16a to 16d in the changeover switch S2 with the rearview mirrors R and L. Referring to FIG. 15, symbol M1 represents an electric motor for vertically adjusting the right-hand mirror R, symbol M2 representing an electric motor for horizontally adjusting the right-hand mirror R, symbol M3 representing an electric motor for vertically adjusting the left-hand mirror L, and symbol M4 representing an electric motor for horizontally adjusting the left-hand mirror L.

The operation of the switch of the first embodiment will now be described.

Reference will be made to the case of controlling the right-hand mirror R by pushing the push button 19a of the changeover switch S2. When the push button 19a is pushed, the slide block 17 is slid toward the left in FIG. 11 and its movable contacts 18a and 18b respectively close the contacts l and 16a together and the contacts m and 16c together so that the switch S1 is connected with the right-hand mirror R. (See FIG. 15.)

When the operation button 11 is pushed thereafter, the engagement piece 11c of the operation button 11 enters the deepest portion of a concave on the jagged cam surface 15a (See FIG. 10.) and the switch elements A and F are closed. Then, the electric motor M1 rotates in such a direction as changes the angle of the right-hand mirror R upward. Even if any of the other operation buttons 12 to 14 is pushed at this time, the engagement piece thereof is not allowed to enter the deepest portion of a concave on the jagged cam surface 15a and therefore no other switch elements are closed.

When only the operation button 12 is pushed, the engagement piece 12c thereof contacts the jagged cam surface 15a and turns the interceptor 15 until it enters the deepest portion of a concave on the jagged cam surface 15a. As a result, the switch elements B and E are closed and the electric motor M1 rotates in a reversed direction so as to change the angle of the right-hand mirror R downward.

When only the operation button 13 is pushed, the engagement piece 13c thereof behaves in the same way as mentioned above. Then the switch elements C and F' are closed and the electric motor M2 rotates in such a direction as changes the angle of the right-hand mirror R toward the left.

When only the operation button 14 is pushed, the switch elements D and E' are closed in the same way as mentioned above. Then, the electric motor M2 rotates in a reversed direction so as to change the angle of the right-hand mirror R toward the right.

When the push button 19b of the changeover switch S2 is pushed, the left-hand mirror L is controlled in the same way as described above.

FIGS. 16 to 21 illustrate a second embodiment of the present invention. The second embodiment is different from the aforesaid first embodiment mainly in the construction of movable contacts in switch elements. In the second embodiment, cup-shaped elastic portions are provided over fixed contact components and a movable contact is fixed inside the top of each of the elastic portions. Therefore, the movable contacts may be made of a metal unlike in the first embodiment. Connections between the switch elements are much the same as in the first embodiment.

The second embodiment will now be described in detail with respect to the differences from the first embodiment. An insulating sheet 24 is laid on top of an insulating base plate 2 of a printed circuit. The insulating sheet 24 has cup-shaped elastic portions 25a to 25h corresponding to a plurality of fixed contact components. The elastic portions 25a to 25h may be made of rubber integrally with the insulating sheet 24, or they may be made of a different insulating material separately from the insulating sheet 24. Movable contacts 26a to 26h are fixed inside the top of the elastic portions 25a to 25h. The movable contacts 26a to 26h may be made of pressure conductive rubber consisting of silicone rubber and metal particles, or they may be metal plates, etc.

Eight switch elements A to F' are thus formed on the base plate 2, and they are connected by means of printed conductors 6 so as to form two switch means for changing the polarity of electric power supply. The arrangement and connection of fixed contact components on the base plate 2 are much the same as in the first embodiment as shown in FIGS. 20 and 21.

Driving means as follows are disposed over said switch elements A to F'.

An inclinable operation button 27 is disposed over the eight elastic portions 25a to 25h of the insulating sheet 24. The operation button 27 is square in its plan view, and the outside of its top is engaged with the corners between the inner walls of a housing 1 and the top plate thereof. Projecting push buttons 27a to 27d provided on the top of the operation button 27 protrude upward from openings 1f provided in the top plate of the housing 1. As shown in FIG. 19, the operation button 27 is provided at its bottom with four pressing surfaces 27e to 27h so divided by two diagonal lines, said pressing surfaces respectively lying on top of two elastic portions 25a and 25b, 25c and 25d, 25e and 25f, and 25g and 25h. Therefore, the pressing surface 27e corresponds to the switch elements A and F, the pressing surface 27f corresponding to the switch elements B and E, the pressing surface 27g corresponding to the switch elements C and F', the pressing surface 27h corresponding to the switch elements D and E'. Thus, each pressing surface of the operation button 27 corresponds to two switch elements.

The operation button 27 is provided in the center and four corners of its bottom with projections 27i and 27j to 27m for preventing the simultaneous operation of more than one pressing surface thereof. If two push buttons, for example 27a and 27c or 27a and 27d, are pushed with the same force at the same time, the projection 27i passes through an opening 24a in the center of the insulating sheet 24 and contacts the base plate 2 while one of the projections 27j to 27m passes through one of notches 24b at the four corners of the insulating sheet 24 and contacts the base plate 2, so that switch elements corresponding to two pressing surfaces, for example F and F', A and D or F and E', are not closed at the same time, thus the possibility of the oblique movement of the mirror or short circuit being eliminated. Therefore, the lengths of the projections 27i and 27j to 27m are such that the projections are out of contact with the base plate 2 when one of the push buttons 27a to 27d is properly pushed and corresponding switch elements are closed while the projections come into contact with the base plate 2 so as to prevent any switch elements from being closed when a plurality of push buttons are pushed at the same time.

The construction of a changeover switch S2, etc. is substantially the same as in the first embodiment.

The operation of the second embodiment will now be described. The right-hand mirror R is controlled as follows: When the push button 19a of the switch S2 and then the position 27a of the operation button 27 are pushed, the elastic portions 25a and 25b of the insulating sheet 24 are contracted so as to bring the movable contacts 26a and 26b into contact with the fixed contact components 3f, 4f and 3a, 4a. Then, the switch elements A and F are closed and the electric motor M1 rotates in such a direction as changes the angle of the right-hand mirror R upward. When the operation button 27 is released thereafter, the operation button 27 returns to its neutral position as shown in FIG. 17 by the elasticity of the elastic portions 25a and 25b. Such elastic action of the elastic portions 25a and 25b gives a good feeling of clicking.

When the position 27b of the operation button 27 is pushed, the switch elements B and E are closed and the electric motor M1 rotates in a reversed direction so as to change the angle of the right-hand mirror R downward.

When the position 27c of the operation button 27 is pushed, the switch elements C and F' are closed and the electric motor M2 rotates in such a direction as changes the angle of the right-hand mirror R toward the left.

When the position 27d of the operation button 27 is pushed, the switch elements D and E' are closed and the electric motor M2 rotates in a reversed direction so as to change the angle of the right-hand mirror R toward the right.

When the position 27b, 27c or 27d is pushed, the elastic portions 25c and 25d, 25g and 25h, or 25e and 25f behave in the same way as when the position 27a is pushed.

When the push button 19b of the changeover switch S2 is pushed, the left-hand mirror L is controlled in the same way as described above.

As many apparently widely different embodiments of this invention may be made without departing from the spirit and scope thereof, it is to be understood that the invention is not limited to the specific embodiments thereof except as defined in the appended claims.