Multiple Switch Construction

Abstract

Multiple switches produced as a flat panel embodying the basic principle of laminates of electrical conductors in desired patterns assembled as stratifications in close proximity but separated by spacers and covered by resilient material facilitating momentary pushbutton operation of companion switch elements thereof, the separators isolating companion switch elements of the stratified laminates within switching zones identified by indicia or pushbutton pads on the resilient cover.

Description

BACKGROUND

This invention relates to multiple switches in a single keyboard and the like and more particularly to the provision of momentary switches in large blocks as distinguished from numerous independent switches assembled into a common block or unit.

Heretofore, most conventional momentary switches of the pushbutton type have been produced as individual units. Normally, such switches include a plunger which when depressed will either mechanically engage or magnetically energize a pair of contacts to close an electrical circuit. In some cases a plunger carries a magnet for shifting the latter into a position to excite or energize an active element to effect a sensor used in a remaining circuit as an indication of closed contact.

Such momentary switches of the prior art are not conducive to close proximity of finger tab pushbuttons as in a keyboard or the like. This is so because the mounting of individual switches, leverages and sensors in close relation becomes a tedious and time consuming task often fraught with error and faulty connections when later tested. In some applications such as computer keyboards, electric typewriters and the like the output currents from individual switches have to be encoded in order to be understood by the remaining circuits. Such encoding usually requires solid state elements such as diodes, transistors and/or integrated circuits.

THE PRESENT INVENTION

It is an object of the present invention to overcome the foregoing objectionable aspects in the manufacture and construction of multiple switches. To this end it is an object to provide momentary type switches in large blocks arranged in various configurations and patterns. This object contemplates producing such multiple switches by photography and chemical milling or metal etching processes commonly known as printed circuitry.

It is another object of this invention to produce multiple switches by the use of printed circuits on base blocks coordinated with gang contacts produced as metal stampings in such a manner as to require little or no tooling and a minimum of labor in assembly.

It is a still further object to provide a relatively simple and compact multiple switch assembly with components produced as laminates directly over a flat base block to thereby minimize cost in both assembly and manufacture. In this connection it is contemplated that the components of the multiple switches can be printed and cut out in any design or configuration of a keyboard or switch panel as desired superimposed one above the other whereby upon assembly of such components complete switching means is achieved.

It is yet another object to mass produce multiple switch panels by laminates of electrical conductors stratified in close proximity for operation of each individual switch upon finger pressure applied thereto. In this connection it is contemplated that the laminates be spaced by dividers beneath a resilient cover having indicia locating and/or identifying the individual switch therebelow.

With the foregoing objects in mind it will be understood that the multiple switches of the present invention contemplate a construction requiring a minimum of parts within a minimum of space, eliminating soldering and hand assembly of individual switches to thereby produce keyboards and switch panels with greater economy.

These and other objects and advantages of the present invention will become apparent from a reading of the following description of the light of the accompanying three sheets of drawing in which:

FIG. 1 is a plan view of a solid-state keyboard embodying the multiple pushbutton switches of the present invention;

FIG. 2 is a section through FIG. 1 taken along line 2-2 thereof;

FIG. 3 is a fragmentary perspective view of a portion of FIG. 1, at larger scale and partially broken away for purpose of illustration;

FIG. 4 is an enlarged detail section taken substantially along line 4-4 in FIG. 3;

FIG. 5 is a section similar to that of FIG. 4 showing modified fixed conductor elements;

FIG. 6 is a fragmentary perspective view of a portion of FIG. 5;

FIG. 7 is a fragmentary perspective view of a printed circuit complimentary to FIG. 6;

FIG. 8 is a wiring diagram of a system applicable to the multiple switches of the present invention;

FIG. 9 is a fragmentary plan view of a grid-type arrangement of multiple groups of contacts for the switches of the present invention;

FIG. 10 is a fragmentary plan view of one flexible contact element for ring-type pressure switching means;

FIG. 11 is a section through a switching means embodying the element of FIG. 10;

FIG. 12 is a perspective view of the contact element of FIGS. 10 and 11;

FIG. 13 is a fragmentary plan view of another form of flexible contact element for center-type pressure switching means;

FIG. 14 is a section through a switching means embodying the element of FIG. 13;

FIG. 15 is a perspective view of the contact element of FIGS. 14 and 15;

FIG. 16 is a perspective view of another form of flexible support for the resilient press button tab cover of the switches;

FIG. 17 is a section through an assembly embodying the switch mechanisms of FIGS. 10, 12 and 16; and

FIG. 18 is a section through an assembly embodying the switch mechanism of FIGS. 13, 15 and 16.

GENERAL DESCRIPTION

The multiple switches of the present invention utilize the basic principle of a printed circuit having a selected number of fixed contact elements etched on a base panel and divided into switching areas by spacers which separate a resilient membrane cover therefrom, the resilient membrane having a plurality of integrally formed movable contact elements superimposed therebeneath for independent flexing into connection with the fixed contacts upon depression of the membrane cover by a human finger at any selected switching area.

Three forms of multiple switches embodying the basic principle of the present invention are illustrated in the accompanying drawings:

A. The most simple form is shown in FIGS. 1 through 9;

B. A modification and more sophisticated form thereof is shown in FIGS. 10 through 15; and

C. The preferred form of the present invention is shown in FIGS. 16 through 18.

A. SIMPLE FORM

Referring to FIGS. 1 through 4 the simplest form of the multiple switches of the present invention comprises a nonconductive base panel 20 having a photographically printed circuit etched on its upper surface to provide a plurality of fixed contact elements 21 thereon divided by a screen of spacers 23 into separate switch areas or zones 22. Each of the contact elements 21 have independent electrical connection to one side of an electrical circuit through a suitable jack arrangement 24 which may be formed on the base 20 as a receptacle for a gang plug 25 as shown in FIG. 3. The screen of spacers 23 is preferably secured to the top surface of the base panel 20.

A resilient cover 26 is fixedly mounted over the spacers 23 and is suitably secured and sealed around the perimeter of the base panel 20 as at 27. The inner or lower surface of the resilient cover 26 has a layer 28 of electrically conductive material formed as a film thereon to provide a movable contact element of the multiple switches 19. The spacers 23 are of slight height so as to support the electrically conductive film 28 in spaced, yet proximal relation to the respective fixed electrically conductive elements 21 on the upper surface of the base. The film 28 supported on the spacers and lower surface of the resilient cover 27 may be plated with suitable material to reduce the danger of corrosion. This electrically conductive film 28 is adapted to have electrical connection to the other side of the aforementioned electrical circuit through a plug and jack 29. This side of the electrical circuit may be the hot line or ground line of the circuit as desired. It is also contemplated that the film 28 may be a printed circuit similar to that of the one on the base 20 to provide independent switches of separate circuits.

The resilient cover 26 has switch identifying indicia 30 thereon directly above each switch area 22 and is of sufficient elasticity as to be depressed by a person's finger as illustrated in FIGS. 3 and 4 to close circuit through the fixed contact element 21 in a particular zone. The elasticity of the resilient cover 26 is such as to snap back to its normally stretched condition upon release of the finger pressure to thereby only momentarily close the respective switch thus operated.

The foregoing construction thus provides multiple switches 19 which may be arranged as a keyboard as shown in FIG. 1; in lineal strips or cut up into independent individual switches within each of the areas 22 divided by the spacers 23. The space between the cover 26 and panel 20 is hermetically sealed about the perimeter of the base panel 20 to protect the contact elements 21 and 28 from the effects of humidity and dust. The hermetically sealed space may also be filled with a special gas conducive to improved electrical transmission between the contact elements upon closure thereof.

GRID-TYPE CONTACTS

Referring to FIGS. 5 through 9 the construction of the multiple switches 19 is identical except for the provision of grid-type contact elements in the printed circuitry. Consequently, like reference numerals are applied to like parts thereof and modifications designated by lettered exponents for the purpose of clarity. In this connection the fixed contact elements 21 of the simple form may be provided by a group of contact elements 21b on the upper surface of the base panel 20 as illustrated in FIGS. 5, 6 and 7. The several fixed contact elements 21b of each group thereof may be interconnected clusters of contacts as illustrated in FIG. 9 such that contact of any one or more contact 21b of each group thereof by the movable contact element 28 will assure completion of the desired electrical circuit.

As shown in FIGS. 7 and 8 each of the fixed contact elements 21b may have connection to independent wiring 31 for closing multiple encoded circuits such as would occur in a computer keyboard. If desired each of the fixed elements 21b may be a gridlike cluster separately wired as in FIG. 9 or utilizing the binary system shown in FIG. 8.

B. MODIFIED FORM

Referring to FIGS. 10 through 15 a modification of the simple form shows a construction utilizing the basic principles of the present invention in a more sophisticated manner. Here again like reference numerals are applied to like parts and the modified aspects thereof distinguished by primed or lettered exponents.

In this form of the invention the base panel 20 remains the same, but has its printed circuit providing fixed contacts elements 21' which may be in the form of a ring or segments thereof as desired. This is to achieve more positive electrical contact or in the case of segmental fixed elements 21', to provide for binary circuitry as exemplified in FIG. 8.

In this modified embodiment the movable contact elements although not directly attached to the resilient cover are beneath the latter and superimposed over and in proximity to the fixed contact elements within the areas 22 defined by the spacers 23 as in the basic structure. To this end the movable contact element may take various forms 28' (FIG. 10) or 28b (FIG. 13) conducive to the Grid, clustered or segmental arrangement of fixed contact elements 21' as the case may be.

In the present disclosure the movable contact elements are preferably formed in a gang stamping 35 on a sheet of tempered beryllium copper or the like having a high degree of electrical conductivity. In the gang stamping 35 thus formed the contact element for each switch unit is confined within a frame 36 which registers with the screen of spacers 23 on the base panel 20 for support thereon. Within this frame 36 one or more spider legs 37 extend centrally inward to the movable contact element 28' or 28b as the case may be to support the same in yieldable suspension above the fixed contact element in each switch cavity or area 32 as shown in FIGS. 11 and 14.

As illustrated in FIGS. 10, 11 and 12 the movable contact elements 28' is in the form of an annular flat ring 38 having spokelike fingers 39 extending radially inward therefrom toward an open center. In FIGS. 13, 14 and 15 the movable contact element 28b is in the form of a solid flat center 38' from which a plurality of spiderlike fingers 39' extend radially outward for yieldable contact with a ringlike fixed contact element 21'.

In either form of movable contact 38' or 28b the spiderlike legs 37 afford yieldable suspension thereto. Four such legs 37 is preferable in each frame 36, each leg 37 having integral connection at its base end 40 to one side of the frame 36 adjacent one corner thereof. The legs 37 are separated form the adjacent right angled side of the frame and extend approximately half way across the square frame 36. Each leg 37 terminates in a hooklike bend 41 the extreme end 42 of which is integrally connected to the contact element 28' or 28b as the case may be. In the case of the spoked center element 38 for ring-type pressure the extreme ends 42 terminate at approximately 90.degree. from the corner of the frame 36 where the particular spider leg 37 is connected to the frame. In the case of the solid centered contact 38' having spiderlike fingers 39' for center-type pressure, the extreme end 42 of each spider leg 37 terminates at approximately a full 180.degree. relative to the corner of the frame 36 where the particular spider leg 37 is connected to the frame.

By this arrangement when any downward pressure is applied against either the open center contact 38 or the solid center contact 38' the spider legs 37 associated therewith are flexed while the center contacts and their spokes or fingers move spirally perpendicular to the flat upper surface of the printed circuit; i.e., turning while moving vertically within the switch zone 22 confining the same.

As in the basic form of the invention pressure against any one of the center contacts 38 or 38', of the movable contact elements 28' or 28b is applied through the resilient cover referred to as 26' in FIGS. 11 and 14. The resilient cover 26' may be secured adjacent the upper surface of the sheet of gang stamping 35. Thus upon finger pressure against an identifying tab 30' formed on the upper surface of the cover 26' the center contact 38 or 38' will move vertically and spirally into wiping electrical contact with the fixed contact element 21' below it.

To assure complete finger pressure and release thereof via the resilient cover 26' the latter may be spaced slightly from the yieldable stamping 35 which by its own resiliency will assume a flat condition, spaced from the fixed contact element below. In such case the resilient cover 26' is mounted on extensions 23' of the spacers 23 and aligned perfectly above the same. In addition thereto the fingering tab 30' may be provided with a downwardly projecting bead 43 for engaging the center 38 or 38' of the movable contact element 28' or 28b as the case may be.

In the case of the solid center-type movable contact element 38' the bead 43 on the cover is centrally located as in FIG. 14. In the case of the open center-type movable contact element 38 the bead 43' on the cover 26' is of annular form as shown in FIG. 11 so as to apply annular pressure uniformly to the inner ends of all of the spokelike fingers 39 extending radially inwardly from the ring 38.

In either case, upon downward pressure of the depending bead 43 or 43' the radially extending arms 39' or spokes 39, respectively, may flex slightly upon engagement with the fixed contact element or elements 21b therebelow. In other words, although full pressure downwardly by either the solid bead 43 or ring-type bead 43' forces the contact elements 38 or 38' all the way down to the upper surface of the base panel 20 the spokelike fingers 39 or the spider fingers 39' will flex by reason of their extreme ends engaging the fixed contact elements 21b on the base. This is an important feature of the present invention because by this phenomenon a wiping action of the finger tips over the fixed contacts occurs. Moreover, in the case of the spider fingers 39' of FIGS. 13, these fingers tend to effect a wrap around connection with annularly arranged fixed contact elements 21b as will be apparent in FIG. 14.

C. PREFERRED FORM

Referring now to FIGS. 16, 17 and 18 the preferred embodiment of the present invention is concerned with a more substantial support for the resilient cover. Under extreme variations in temperature the resilient cover may have a tendency to become too soft or too rigid as the case may be. For this reason it is proposed to reinforce the resilient cover 26' with a gang-type stamping of heat treated or tempered spring steel 35'.

This spring steel stamping 35' is formed much the same as the tempered beryllium copper sheet 35 for the movable contact elements 28' and 28b as previously explained in connection with FIGS. 10, 12, 13 and 15. Referring to FIG. 16 it will be noted that the spring steel stamping 35' has the same characteristics as the sheet 35 in FIG. 12. Consequently, like parts thereof are identified by like reference numerals and distinguished therefrom by primed exponents.

As seen in FIG. 16 the stamping 35' is cut to provide a frame 36' conforming to the screen of spacers 23 for support thereon as illustrated in FIGS. 17 and 18. Within each frame 36' the stamping 35' has a number of spiderlike legs 37' formed similar to those 37 on the movable contact elements 28' of FIG. 12. Each of the legs 37 terminates in a hooklike bend 41' the terminal end 42' of which has integral connection to a center ring 48 similar to that 38 on the movable contact element 28' of FIG. 12.

As best seen in FIGS. 17 and 18, the frame 36' is supported on the extensions 23' of the spacers 23. The resilient cover 26C may have depending ribs 23C registerable with the spacers 23 and extensions thereof 23' for support thereon. It should here be noted that the frames 36--36' and extensions 23' of the spacers 23 are secured together by suitable adhesive cement so as to form a continuous partition between the base 20 and the resilient covering 26C.

Referring again to FIG. 16 it will be noted that each ringlike center 48 of the spring steel stamping is secured to the resilient cover 26C in annular grooves 49 formed in a depending bead 43C axially below each fingering tab 30C on the cover. This is also clearly illustrated in both FIGS. 17 and 18.

In the case of FIG. 17 the depending bead 43C is in the form of an annulus for ring-type pressure engagement with the movable center contact element 38. That is, with the inwardly extending spokelike fingers 39 of FIGS. 10 and 12 as applied in FIG. 17 for applying annular pressure to the spokes 39 as already explained.

In the case of FIG. 18 the depending bead 43C has a solid knoblike center 50 disposed to exert downward pressure axially of and upon the solid center-type contact element 38b of FIGS. 13 and 15 as applied in FIG. 18.

From the foregoing it will be appreciated that the multiple switch construction of the present invention provides a simple form of switching means which is inexpensive from the standpoint of manufacture involving a minimum of number of parts by reason of printed-type circuitry and mass stamping of switching elements and the least effort in labor and assembly. The switching contacts thus formed and constructed results in relatively flat platelike switch banks, keyboards and the like having a wide application in any industry requiring momentary switching functions.

Claims

Having thus described my new multiple switch construction in specific detail what I claim as new and desire to protect by Letters Patent is:

1. In a multiple switch construction in which stratified laminates superimposed in spaced relation and in close proximity one upon another comprise in combination:

1. an electrically nonconductive base panel having one surface thereof divided into a plurality of switching areas;

2. a fixed electrically conductive switch element fixed upon said surface of said base panel within each of said switching areas thereon;

3. depressible means supported on said base panel in spaced relation to said surface thereof and selectively depressible toward the latter within any one of said switching areas thereon;

4. a flexible electrically conductive switching element supported in spaced relation to said base panel with said depressible means for movement by the latter into electrical contact with the particular fixed electrically conductive switch element within the switching area into which said depressible means is selectively depressed; and

5. each of said fixed electrically conductive elements within a switching area comprising a plurality of fixed contact members arranged on said base panel for collective engagement by said flexible electrically conductive element upon movement thereof under depression of said depressible means toward said base panel.

2. In a multiple switch construction in which stratified laminates superimposed in spaced relation and in close proximity one upon another comprise in combination:

1. an electrically nonconductive base panel having one surface thereof divided into a plurality of switching areas;

2. spacers mounted on said one surface of said base panel for dividing the same into a plurality of switching areas;

3. a fixed electrically conductive switch element fixed upon said surface of said base panel within each of said switching areas thereon;

4. depressible means supported on said base panel in spaced relation to said surface thereof and selectively depressible toward the latter within any one of said switching areas thereon; and

5. a flexible electrically conductive element comprising a stamping of substantially flat-rigid electrically conductive material having framelike portions thereof conforming to and supported on said spacers and integral movable switch elements suspended from said framelike portions for flexing movement into electrical contact with the fixed electrically conductive switch element within the switching area into which said depressible means is selectively depressed.

3. A multiple switch construction in accordance with that of claim 2 in which each of said fixed electrically conductive elements within a switching area confined within said spacers comprises a plurality of fixed contact members arranged as a grid on said base panel for collective engagement by said flexible electrically conductive element upon movement thereof under depression of said depressible means toward said base panel.

4. The multiple switch construction in accordance with that of claim 2 in which each of said integral movable switching elements comprises:

a. a medial contact element;

b. two or more spider legs each having its base end equidistant from that of the other spider legs an integral to the framelike portions supported on said spacers and extending inwardly therefrom into the switching area defined by the spacers; and

c. each of said spider legs being of a length greater than the shortest distance between its base end and said medial contact element to thereby facilitate flexing of said spider legs toward said base panel while spirally supporting said medial contact element parallel thereto for during perpendicular movement toward said base panel and wiping contact of the medial contact element with the fixed electrical contact element within a switching area upon depression of said depressible means into such switching area.

5. A multiple switch construction in accordance with that of claim 4 in which said medial contact element includes a plurality of substantially radially disposed fingers adapted to flexingly engage said fixed electrically conductive element on said base panel.

6. A multiple switch construction in accordance with that of claim 5 in which each of said fixed electrically conductive elements in a switching area comprises a plurality of segmental contact members arranged on said base panel within the peripheral reach of the radially disposed fingers on said medial contact element for flexing said fingers upon engagement thereof with said segmental contact members upon perpendicular movement of said medial contact element relative to and into engagement with said base panel.

7. The multiple switch construction in accordance with that of claim 6 in which said segmental contact members are rounded bead like projections above said one surface of the fixed electrical contact element on said base panel whereby to effect a wraparound wiping engagement of said radially disposed fingers during flexing thereof upon downward movement of said medial contact member into engagement with said base panel.

8. The multiple switch construction in accordance with that of claim 7 including a spring steel laminate disposed between said flexible electrically conductive element and said depressible means for supporting the latter and comprising in combination:

a. nonconductive extensions on said spacers disposed on the framelike portions of the flexible electrically conductive element;

b. a plurality of integrated frames formed in said spring steel laminate conforming to said nonconductive extensions of said spacers and secured thereto;

c. a plurality of spring steel spider legs extending inwardly of each of said spring steel framelike portions and having inwardly bowed ends terminating in a common central ring; and

d. a depending central annular pushbutton projection on the underside of said depressible means within each of said switching areas and supported on said common central ring and extending therethrough for engaging the movable medial contact element therebelow for moving the latter into electrical contact with the fixed electrically conductive element on said base panel upon depression of said depressible means in the respective switching area.

9. In a multiple switch construction in which stratified laminates superimposed in spaced relation and in close proximity one upon another comprise in combination:

1. an electrically nonconductive base panel having one surface thereof divided into a plurality of switching areas;

2. a fixed electrically conductive switch element fixed upon said surface of said base panel within each of said switching areas thereon;

3. depressible means supported on said base panel in spaced relation to said surface thereof and selectively depressible toward the latter within any one of said switching areas thereon;

4. a flexible electrically conductive switching element supported in spaced relation to said base panel with said depressible means for movement by the latter into electrical contact with the particular fixed electrically conductive switch element within the switching area into which said depressible means is selectively depressed; and

5. a spring laminate of resilient material interposed between said depressible means and said flexible switching element, said spring laminate including a plurality of spring stampings corresponding in number and location to each of said plurality of switching areas providing a positive spring return for each of said depressible means.

10. The multiple switch construction in accordance with that of claim 9, including in combination:

1. spacers mounted on said one surface of said base panel for dividing the same into a plurality of switching areas.

2. nonconductive extensions on said spacers disposed on the framelike portions of the flexible electrically conductive element;

3. a plurality of integrated frames formed in said spring laminate conforming to said nonconductive extensions of said spacers and secured thereto;

4. a plurality of spring spider legs extending inwardly of each of said spring framelike portions and having inwardly bowed ends terminating in a common central ring; and

5. a depending central annular pushbutton projection on the underside of said depressible means within each of said switching areas and supported on said common central ring and extending therethrough for engaging the movable medial contact element therebelow for moving the latter into electrical contact with the fixed electrically conductive element on said base panel upon depression of said depressible means in the respective switching area.

11. In a multiple switch construction having nonconductive spacers defining independent switching areas, the improvement comprising switching elements constructed of a panel divided into a plurality of framelike portions having integral movable switch elements suspended from said framelike portions for flexing movement, said integral movable switching elements including:

1. a medial contact means;

2. a plurality of spider legs having base ends thereof equally spaced about said medial contact means, said spider legs being integral to the framelike portions supported on said spacers and extending inwardly therefrom into the switching area defined by the spacers; and

3. each of said spider legs being of a length greater than the shortest distance between its base end and said medial contact element to thereby facilitate flexing of said spider legs toward said base panel while supporting said medial contact element parallel thereto for substantially linear movement upon depression thereof in a direction substantially perpendicular to the plane of said panel.

12. A multiple switch construction in accordance with that of claim 11 in which said medial contact element includes a plurality of substantially radially disposed fingers.

13. The multiple switch construction of claim 11 in which the spider legs extend across one side of said framelike portions and then inwardly toward the center thereof.

14. The multiple switch construction of claim 13 in which the inner ends of said spider legs of each frame include a plurality of elongated fingers for providing multiple contact.

15. The multiple switch construction of claim 13 in which the inner ends of said spider legs of each frame are interconnected and include a plurality of elongated fingers for providing multiple contact.

16. The multiple switch of claim 15 in which the elongated fingers extend substantially radially inwardly.

17. The multiple switch of claim 15 in which the elongated fingers extend substantially radially outwardly.