US3127482A - Multiple pushbutton switch with sliders operating switch arms - Google Patents

Abstract

983,571. Cam-operated switches. GENERAL ELECTRIC CO. July 12, 1961 [July 14, 1960], No. 25224/61. Heading H2B. A multiple push-button switch similar to that of Specification 605,170 and having normally-closed contacts 70, 100 which may be opened by cam surfaces on sliders A... E which are movable, longitudinally by pushbuttons 62, also has one or more sets of normally open contacts 70, 111 which are similarly operable. Each button 62 actuates two pushrods, such as 42, having rounded ends 56 acting on sloping surfaces on the sliders.; A slider F has hook portions which retain any button in the depressed position against the bias of a return spring 66 until released by depression of a further button. A further slider G causes momentary actuation of one set of contacts during each depression of a button.

Description

March 31,1964 P. HUTT 3,127,482

MULTIPLE PUSHBUTTON SWITCH WITH SLIDERS OPERATING SWITCH ARMS March 31, 1964 HUT-r 3,127,482

MULTIPLE PUSHBUTTON SWITCH WITH SLIDERS OPERATING SWITCH ARMS Filed July 14, 1960 '7 Sheets-Sheet 2 P. HUTT March 31, 1964 MULTIPLE PUSHBUTTON SWITCH WITH SLIDERS OPERATING SWITCH ARMS 7 Sheets-Sheet 3 Filed July 14, 1960 March 3l, 1964 p, HUTT 3,127,482

MULTIPLE PUSHBUTTON SWITCH WITH SLIDERS OPERATING SWITCH ARMS Filed July 14, 1960 '7 Sheets-Sheet 4 3641 sel asm am, 360

se; sa, asd

March 31, 1964 P. HUTT 3,127,482

MULTIPLE PUSHBUTTQN swITcH WITH sLIDERs OPERATING SWITCH ARMS Filed Jly 14, 1960 7 Slfleens-Sheeil 5 March 31, 1964 P, HUTT 3,127,482

MULTIPLE PUSHBUTTON SWITCH WITH SLIDERS OPERATING SWITCH ARMS Filed July 14, 1960 7 Sheets-Sheet 6 March 31, 1964 P. HUTT 3,127,482

MULTIPLE PUSHBUTTON SWITCH WITH SLIDERS OPERATING SWITCH ARMS Filed July 14, 1960 7 Sheets-Sheet 7 F/9. az

57a. 5w Je .a g s70- rf rrrrrmruuumr United States Patent @moe 3,127,482 Patented Mar. 31, 1964 3,127,482 MULTIPLE PUSHBUTTGN SWITCH WITH SLIDERS OPERATING SWITCH ARMS Philip Hutt, Milford, Conn., assignor to General Electric Company, a corporation of New York Fried Jury 14, 1ers, ser. No. 42,375 lll Claims. (Cl. 200-5) This invention relates to a pushbutton switch, and particularly, a multiple pushbutton switch with a series of manually controlled reciprocating sliders for controlling the operation of several circuits connected through the switch.

Multiple pushbutton switches of the type exemplified by the Andrews Patent No. 2,431,904 (which is assigned to the same assignee as is the present invention) have been used in great numbers as appliance switches for electric ranges, washing machines, and room air conditioners, etc., to control the circuitry thereof. In such switches, a specially constructed group of longitudinally extending sliders are positioned in side-by-side relationship within a switch base. These sliders are arranged to transmit actuating force from manually depressible pushrods to movable Contact blades and also provide an interlocking mechanism for the switch by preventing simultaneous operation of any other pushrods when one pushrod is being depressed and returning any previously depressed pushrod back to its outer (normal) position upon the subsequent depression of another of the pushrods. To effect these functions, the sliders are formed with groups of diagonal working surfaces that are dis` posed in general alignment to cooperate with the pushrods, and cam surfaces for actuating the movable contact blades. An actuating portion of an associated pushrod is extended through each aligned group of working surfaces and the working surfaces are so arranged on the respective sliders that predetermined movement of certain sliders will occur when any one of the pushrods is depressed and any previously depressed pushrod will be returned to its outer (normal) position. The cam surfaces are formed on one of the edges of certain of the sliders and positioned with respect to associated movable contact blades in the switch housing so that longitudinal movement of a slider upon which a carn surface is formed in a particular direction to the right or left within the switch will cause a normally closed movable contact blade to be cammed open.

In many multiple pushbutton switch applications, it is desirable that the switch be capable of controlling a large number of circuits. To eiiiciently effect this purpose, by means of prior art practice the number of sliders required to control these circuits has necessitated an undesirable increase in cost of the over-al1 switch as well as an increase in the switch dimensions and an increased amount of frictional drag between the respective sliders. It is therefore desirable to provide an improved multiple pushbutton switch of the aforementioned type which is capable of controlling a large number of circuits while requiring a substantially reduced number of sliders.

The principal object of the present invention is to provide an improved multiple pushbutton switch with a novel and low-cost means for controlling a relatively large number of circuits.

A further object of this invention is to provide an improved multiple pushbutton switch which is capable of controlling a relatively large number of movable contacts with a substantially reduced number of reciprocating sliders.

A still further object of my invention, is to provide an improved multiple pushbutton switch having certain movable contact blades `which are cammed open and cery ing sliders.

tain movable contact blades which are cammed closed by reciprocating sliders.

In carrying out my invention, in one form thereof, I apply it to a multiple pushbutton switch unit for controlling a plurality of circuits by movement of reciprocat- Each slider has a series of inclined working surfaces which are acted upon by certain pushrods. Certain sliders also have cam surfaces for engaging a plurality of switch arms or movable contact blades. The switch arms are all biased in one direction to a normal position and are movable by the cam surfaces of certain of the sliders against their biasing forces to a second position. By my invention, a first type of fixed contacts is provided which is engageable by selected ones of the switch arms when the arms are in their normal position. This first type of fixed contacts along with its associated switch arms thus provides a plurality of normally closed pairs oi contacts in the switch which are cammed open. A second type of xed contact is positioned so as to be engageable by at least one other of the switch arms when the other arm is in its second position. This second type of xed contact along with its associated switch arm provides at least one normally open pair of contacts in the switch unit which is cammed closed. By using normally closed switch arms which are cammed to an open position as well as normally open switch arms which are cammed to a closed position in my multiple pushbutton switch unit, a substantial increase in circuit controlling flexibility is thus provided without necessitating any increase in the number of sliders required to control a large number of circuits. An improved multiple pushbutton switching unit which is low in cost and novel in structure has thus been obtained.

Further aspects of my invention will become apparent hereinafter, and the specification concludes with claims particularly pointing out and distinctly claiming the subject matter which I regard as my invention. The invention, however, as to organization and method of operation, together with other objects and advantages thereof, may best be understood by reference to the following description when taken in conjunction with the accompanying drawings in which:

FIG. l is a top View, partially in section and partially broken away, of an improved multiple pushbutton switch unit embodying my invention in one form thereof;

FIG. 2 is a side View of the switching unit of FIG. l with one pushbutton shown in section and one pushbutton in its extreme depressed position;

FIG. 3 is a sectional View taken generally along the line 3--3 of FIG. 2, showing one of the movable arms of my switch unit which is cammed to a contacts open position;

FIG. 4 is a cross-sectional view taken generally along the line 4-4 of FIG. 2, showing one of the movable arms of the switch unit which is cammed to a closed position;

FIG. 5 is an end view of the switch of FIG. l;

FIG. 6 is a penspective view of the switch unit of FIG. l with the mounting bracket, `light barrier and pushbuttons exploded therefrom;

FIG. 7 is a fragmentary exploded perspective view of a portion of the switch unit of FIG. l showing the movable switch arms and their two types of mating fixed contacts;

FIG. 8 is a bottom View of the switch unit of FIG. 1 with most of the cover plate and one vof the switch arms partially broken away to show details of the switching structure;

FIG. 9 is a cross-sectional view taken generally along the line 9-9 of FIG. 8;

FIG. 10 is an exploded perspective view of a iixed 3 contact and its associated terminal for one of the contact pairs of my switch unit which is cammed closed by the sliders;

FIG. 1l is a perspective view of `a pair of switch arms which are axed to 'a series connected integral double terminal;

FIG. y12 is a perspective View of one of the tixed contacts yof my switch unit and its associated terminal, for one of the contact pairs of my switch imit which is cammed open; i FIG. 13 is a layout of the various sliders of my multiple pushbutton switching unit;

FIGS. 14-17 inclusive, are diagrammatic views of the momentary and detent sliders illustrating the effect they have upon the pushrods of exemplary pushbuttons during the successive depression thereof;

FIGS. 18 and 19 rare diagrammatic views illustrating the camming open `of one of the switch arms by its associated actuating slider;

FIGS. 20-22 inclusive, are diagrammatic views illustrating the camming closed of certain movable contact blades by their yassociated predetermined slider combinations; and

FIG. 23 isa diagrammatic view of the contact arrangement in my improved multiple pushbutton switch unit.

Referring in detail Vto the drawings, and in particular to FIGS. 1 and 2, there is shown a multiple pushbutton switch unit 2 wherein my invention has been advantageously employed. Certain features of this switch, other than those claimed herein, are the invention of Stewart A. Woodward, and are described in detail and claimed in the copending application of said Woodward, Seria-l Number 42,815 led concurrently herewith and assigned to the same assignee as the present invention. The switch housing 4 comprises left and right hollow bases 6 and 8 respectively (as shown in FIG. 2), which are held together by mounting bracket 10` `and ia relatively thin elongated cover plate 12. Bases 6 and are similar in construction, having oppositely disposed closed outer end walls 14 and 16 respectively, communicating lopen inner ends 18 and Ztl respectively, and open bottoms. As best seen by viewing FIGS. 2, 5, and 6, bracket 10` is channel shaped, and straddles central upright portions 22 and 214 of the two bases 6 and S to fasten them together in an end-to-end relationship by means of screws 26. rIlhe screws 26 are extended through apertures 28 in horizontal section 30 of bracket 1t) to engage threaded recesses 32 of the upright portions 22 and 24, for rmly securing the bases 6 and 8 together. (See FIG. 6.) With bracket V10 lattached to the two bases, the two longitudinally extending sides 311 of the bracket engage the oppositely disposed longitudinally extending sides 22a, 22b, 24a, and Zdb of the upright portions 22 and 24 to preclude Iany lateral movement of the bases and rigidly secure them to the bracket. (-See FIGS. 3 and 4.) As may be clearly seen in FIGS. l and 2, when the bases 6 and 8 are secured together by bracket 1t), they are spaced apart slightly so that a narrow gap 34 exists between the adjacent lovver portions 33 and 35 lof the bases at their open inner ends 18` and 20. This gap 34 `also extends upwardly on each side of housing 4 to the bottom edges of the bracket sides 31 (as seen in FIG. 2), being formed by bridging the two bases 6 and 8 while they are spaced slightly apart, as shown in FIG. `6, by the attachment of bracket 10 and cover plate 12 thereto. By for-ming switch housing 4 from the two hollow bases 6 `and 3 joined together in slightly spaced apart relationship by bracketiltl, it has been found much easier to control the tolerances (i.e., the dimensional relationships) of the switch housing and reduces the possibility of the occurrence of molding problems in manufacturing bases for such la switch. The particular construction of bases' and 8 along with the means for mounting them together in a multiple pushbutton switch comprises the invention of Stewart A.

d Woodward, and this construction and arrangement are described and claimed in hisraforesaid coperrding application Serial No. 42,815.

To close the open bottom iof hollow bases 6 and 8 of switch 2 and cooperate with these bases to provide a compact housing structure `for the operating mechanism of the switch, the elongated cover plate 12 engages the underside of each base (as shown in FIGS. 2 and 5), being securely attached thereto by spaced oppositely disposed terminals 36 and 37 of the fixed and movable contacts, respectively, which shall be described in detail hereinafter. These terminals, as shown representatively by movable contact *terminal 37a in FIGS. 2, 6, and 8 each extend through cover plate slots 38 (FIG. 8) and aligned or overlying slots 39 (FIG. 3) formed in the upper wall of the base lower portions, being lapped over in the well-known manner to hold the terminals in place and secure the cover plate and bases together. (See FIG. 2.)

To actuate the various switches of my multiple pushbutton switch unit 2, spaced pairs of adjacent pushrods or actuators 41-50 are extended downwardly (as shown in FIG. 9) through appropriate slots formed in bracket section 39 and through top walls 52 and 54 of the bases 6 and 8, into the hollow base portions 53 and 55. These pushrods are reciprocably movable in pairs having integral cylindrically congured actuating portions 56 at their innermost ends which cooperate with pairs of associated aligned groups of inclined upper working edges 1 1@ of sliders A-E to operate the switches. The purpose behind the arrangement of the pushrods in pairs shall become apparent hereinafter. More particularly, sliders A-E are disposed in parallel side-by-side relationship (as shown in FIG. 8). These sliders reciprocate longitudinally in response to the selective depression of pairs of pushrods to control the positioning of switch arms or movable contact blades 6tlg-60h and 50i-60g. 4(See FIG. 8.) The lower edge of each of the sliders A-E, as shown in FIG. 13, has one or more cam surfaces formed upon it. These cam surfaces (a-h and jq) have been identiiied in FIG. 13 by the lower case reference letters according to the letter suiix of the switch arm which the cam surface has been designed to control. As an example, cam surface A-a has been formed on lower edge of slider A for the purpose of controlling the positioning of switch arm 60a. It will be noted that in FIG. 13, the reference letters ascribed to certain slider cam surfaces have been underlined for emphasis (e.g., g). The purpose of such identification is to distinguish between cam surfaces that cam certain switch arms open (these cam surfaces being identified by an ordinary letter) and cam surfaces that cam other switch arms closed (these surfaces being identiiied by an underlined letter). The purpose and effects of using the two diierent types of camming action by the sliders in my switch unit shall be described in detail hereinafter. The Various cam surfaces a-h and j-q are thus arranged on the sliders A-E to alternately engage certain movable contact switch arms and thereby effect the opening and closing of predetermined contact pairs in certain operating positions of these sliders.

In the preferred form of my invention as illustrated,` the inclined working edges 1 1() of the sliders A-E are: arranged on each slider in the form or" consecutive adjacent pairs of similar or coincident edges. In viewing FIG. 13 of the drawings, it will be noted that the inclined working edges of the associated pairs of edges of the sliders A-E have thus been given the same reference numeral to indicate that they are similar and operated by the same pair of pushrods. The inclined working edges on the respective sliders are disposed in the switch unit in the form of generally aligned groups to cooperate with pairs of associated pushrod actuating portions as each pair of pushrods reciprocates. The arrangement of Athe inclined working edges of the sliders is such that the dilerent sliders A-E allow only one pair of pushrods.

l1-50 to be fully depressed at any one time and certain of the sliders act upon any previously depressed pushrod pair to return it to its outermost position upon the subsequent depresison of another pair of pushrods.

Turning now to a consideration of the means for manually controlling each pair of associated pushrods in my switch unit 2, as shown in FIGS. 2 and 7, each pair of the pushrods 411-50 is equipped with a pushbutton 62 which is press tit to the bifurcated outer ends 64 of the pushrods. More particularly, the pushbuttons 62 each have three inner cavities or recesses 62a, 62b, and 62e formed in the underside thereof. (See FIGS. 2 and 7.) Cavities 62a and 62h receive the bifurcated outer ends 64 of an associated pair of pushrods. Cavity 62C is disposed between cavities 6211 and 6211 and is generally cylindrical in configuration for receiving one end 66a of compression spring 66. The other end 66h of each spring 66 tits around a base projecting boss 68 or the head of one of the screws 26 to engage bracket 10. The arrangement of the spring ends in button cavity 62C and around the bases or screws, is such that the spring 66 may run in compresison between bracket and button 62, with a minimal lateral movement. Suitable apertures have been formed in the bracket section 30 so that bosses 68 of the base top walls 52 and 54 project outwardly from the bracket intermediate each pair of bracket slots through which the pushrods are extended. (See FIG. 7.) It should also be noted that light barrier 69 of dark material is suitably positioned between horizontal section 30 of the bracket and the bottoms of the buttons, as shown in FIG. 1.

It will thus be seen that each pushbutton 62 is spring biased to its outermost position by compression spring 66 and is also pressed into engagement with the bifurcated ends of an adjacent pair of parallel pushrods. rl`he pushrods of each pair extend through their appropriate slots in bracket 10 and the top base walls so that the actuating portions 56 of each pair of pushrods transversely overlie coincident pairs of diagonal working edges of the sliders A-E. By arranging the pushrods in pairs, it has been found that the action of each pushbutton 62 upon depression thereor is conveniently stabilized by the reciprocating motion in unison of the associated pushrods. This improved pushbutton action also provides more accurate control over the movement of each pair of pushrods and enhances the dependability and durability of my multiple pushbutton switch unit 2. The particular construction of the pushbutton 62 and its cooperating pair of pushrods along with the cooperating associated switch structure comprises the invention of Stewart A. Woodward, and this construction and arrangement are described and claimed in his aforesaid application Serial No. 42,815.

Turning now to a consideration of the circuit opening and closing elements of my multiple pushbutton switch unit, in viewing FIG. 8, it will be noted that movable contact switch arms or blades 60ct-60h, and 60j-6tlq are all of the same conguration and dimensions. (Blades 6dr and 60s are identical to these, but atypical in their operational aspects, and therefore shall be discussed hereinafter.) These arms are suspended in cantilever fashion from their associated supporting terminals which are located on one side of the switch housing, and they are spaced apart in parallel relationship near the bottom of the housing with each blade having a movable contact button 70 extruded through an opening formed in the free end 74 thereof. (See also FIG. 11.) Blades 6i) (as shown representatively by blades 6011 and 690 in FIG. 11) are L-shaped and include a raised intermediate portion 76 in the elongated section that carries the contact button. Portion 76 has a V-shaped cross-section to enhance the strength of the contact blade and furnish a narrow mechanical contacting surface for engagement with slider cam surfaces. The shorter section 75 of each blade is turned over to furnish a support for the blade, having a slot formed therein for that purpose. Each movable contact supporting terminal has one or two pairs of adjacent lanced projecting iingers 82 (as illustrated by the integral double bridging terminal 37110 of FIG. 1l with its attached blades). The supporting portion 78 of each movable contact blade is attached to its associated supporting terminal by bending over each pair of the ngers 82', as shown in FIG. 1l, after they have received slot 80 of the movable contact blade.

To support the movable contact blades and fulll certain circuit requirements in my switch unit, the movable contact terminals 37 are of four general types. All of these types may be understood by further reference to the perspective view of the integral double bridging terminal 37110 shown in FIG. 11. This terminal, as shown in full, provides a long blade section S3 having a single outer blade portion 84 with a detent hole formed therein for engagement with an associated quick connecting terminal, and a short blade section 86 connected to long section 83 by bridge 88. Another type of double bridging movable contact terminal, such as, for example, terminal 3711]' (FIG. 8) is essentially similar to terminal 37110 (FIG. 11) except that long section 83 is shortened as suggested by the dot-dash lines thereof in FIG. l1, so that the terminal has no outer blade portion and coi prises two similar short sections which are connected together by bridge 88. A third type of movable contact terminal, such as, for example, terminal 37a (FIG. 8) consists of a single long section with the same configuration as section 83 of terminal 37110 (including the outer blade portion). The fourth type of movable contact terminal, such as, for example, terminal 37k of FIG. 8 is a single short section similar to section 86 of FIG. 1l, having no outer blade portion.

Turning now to a very important aspect of my invention, in viewing FIG. 8, it will be noted that my switch unit 2 has two types of fixed contacts therein. Fixed contact terminals such as 36a, 36h, 36g, 36h, 36j, and 36q are each of the type shown in FIG. 12. This terminal includes a long blade section 90 having an outer blade portion 92 with a detent hole formed therein for engagement with an associated quick connecting terminal. Connecting intermediate portion 94 is bent over perpendicularly from one side of section 90 between its outer ends, and xed contact supporting arm 96 is turned over from the upper side 98 of portion 94 (as shown in FIG. 12) to extend back generally toward the middle of but in front of section 90. (See also FIG. 7.) Arm 96 is thus perpendicular to section 90 and portion 94, and it has a contact button 100 `extruded into an aperture formed on the end 102 thereof to mate with a contact button 70 of an associated movable contact blade. The xed contact terminals of the switch unit which support contact buttons ltltl are positioned against the inner side of a lower wall of housing 4 (opposite to the wall which the movable contact terminals are adjacent to), as shown in FIG. 8, with sections 94) of these terminals disposed in generally coplanar fashion, and contact buttons 100 facing outwardly to engage their mating movable contact buttons. The movable contact blades of my switch are all spring biased upwardly so that the free end which carries contact button 70 tends to move away from cover plate V12.. When positioned in my switch unit 2, fixed contact buttons 1410 thus serve to cooperate with their mating movable contact buttons 70 to provide a plurality of pairs of contacts which are normally closed (i.e., spring biased to a contacts closed condition).

To provide a second type of iixed contact in my irnproved multiple pushbutton switch unit 2, and substantially reduce the number of reciprocating sliders required to control a relatively large number or" movable contact blades, on fixed contact terminals 36c-36f, and 36k, I have mounted llexible contact 104. (See FIG. 8.) These contacts 164 are arranged on fixed contact terminals 36e-3612 and 36kf(as shown in FIG. 8), for cooperation with movable contact blades 60C-6W, and 66k. As best seen in FIGS. 7 and ll0, flexible contact 104 comprises a dat supporting portion 106 with a rectangular slot 168 formed therein, and flexible contact portion 110. Contact portion 110 extends angularly from supporting portion 1%, having a curved contact surface 111 adjacent its end for engaging the underside of its mating movable Contact button 70 (as shown in FIG. 4). Supporting portion 106 of each contact 104 is afiixed to one of the terminals 36o-3612 and 36k by means of slot 108 which receives a pair of lanced projecting fingers 112 of the terminal blade 114 in the same manner as previously described for terminal V3'7110 of FIG. 1l, fingers 112 being swaged to overlap the side edges of the slot and thus secure flexible contact 104 to the terminal. Terminal blades 114 of the terminals 36e-36j, and 36k are positioned, as shown in FIG. 8, against the inner side of the same lower wall of housing 4 as blade sections 9i) of the other fixed contact terminals. The curved contact surface 111 of each fiexible contact 104 thus underlies the free end of an associated movable contact blade (as viewed in FIG. 9). Movable contact blades 60C-6M, and 641k are'normally biased upwardly and away from cover plate 12 (as illustrated by blade 60k in FIG. 4), as are all the other movable contact blades. Flexible contacts 1494 thus serve to cooperate with their mating movable contact blades to provide a plurality of pairs of mating contacts which are normally open (i.e., spring biased to a contacts open condition). Flexible contact 104 pivots about its supporting portion 196 when its associated movable contact blade is closed thereupon, to provide overtravel for the flexible contact. This overtravel is important in compensating for variations in the positions of the cooperating movable contact blade which are introduced by manufacturing tolerances.

It will thus be seen that my improved multiple pushbutton switch unit 2 has two different types of'matingcontact pairs therein, i.e., pairs of contacts which are normally biased to a closed condition ('eQg., blade 60a, 'which is normally biased into engagement with contact button 130 of fixed contact terminal 36a) and pairs of contacts which are normally biased to an open condition (e.g., blade 60k which is normally biased ,away from flexible Contact 104 of fixed contact terminal 36k). By combining these two types of mating contact pairs in my switch unit Z, a very large number of movable contact blades may be effectively controlled by a substantially reduced number of sliders. To achieve this beneficial result, and thus enable my switch to control a relatively large nurnber of circuits by a relatively small number of reciprocating sliders, certain of the sliders A-E have been combined to control certain of the movable contact blades yin my switch in an improved manner which shall now be described in detail.

My improved switch unit 2 has -been designed to provide the typical switch pattern shown in Table I.

Table I indicates the circuits which are to be opened j and closed by a switch such as my multiple pushbutton switch unit 2, with an X representing each switch position requiring a circuit to have its controlling contact closed, and an O representing each switch position where it is required rthat a circuit have its contacts open or disengaged.

In designing multiple pushbutton switch units of the type illustrated in the aforementioned Andrews Patent No. 2,431,904, the number of circuits and the number of switch positions have been heretofore low enough so that three, four, or ve sliders have usually been enough to actuate the required movable contact blades. The sliders in these prior art switches have been arranged to actuate or cam contact pairs of one type, such as normally closed contacts, to either an open or a closed condition.

8 TABLE I Typical Switching Pattern Switch Positions Circuit O O O O X O X O 0 O X O X O O O O O X X O X X X X X X X X X X X X X X X X X O X X X O X X X X X VX X X X X X X X X X X O O O O X X O O O X X X X X O O X X X O O X O X X X X X O O X O X O X X O O X X X X O X O O X X O O O O X O O O O O X X O O O X X X X X X X X X O X X X X X O O X X X O O O O O O O O O O X X X X X X X X Where, X-controlling contacts Closed, and O-eontrollng contacts Open The determination of the slider pattern in such switches has been arrived at principally by trial and error procedures, with certain rules serving as tentative guides. For instance, as one of these rules, it is well known that movable contact blades of circuits having directly opposite switching patterns may be controlled by forming appropriate cam surfaces on the same slider and reciprocating the slider in opposite directions (such as right and left) to control the respective circuits. In addition, another rule Well known in the art is that the movable contact blades of circuits which are identical in pattern may also be controlled by the same slider when appropriate cam surfaces are formed on the slider and it is reciprocated in any one direction (such as right or left). On the other hand, it is also well known that the blades of circuits whose switching pattern requires them to be closed simultaneously in any switch position cannot be controlled (i.e., actuated) by cam surfaces formed on the same slider unless these circuits are identical in their switching pattern. An example of such circuits which cannot be controlled by the same slider due to difference in switch pattern is circuits c and d of Table I. Applying the above-mentioned general rules which are well known in 'the prior art, to the typical switching pattern set forth in Table I above, the opposite and identical circuit switch patterns which are shown in Table II are observed.

TABLE II Opposite and Identical Circuit Switching Patterns Switch Positions Circuit g O O O X X O O O X X Opposite )3% )(2 g (X) O O j 0 X Opposite {nl O X 0 0 O O O X X O O X O X X O O X X X sassarese O p O Opposite {g O O X X X X X X X X Same X o X X X X X o o X o X 0 X X X X X O O X Same {11 o o X X X X X X X X q 0 0 X X X X X X X X Where,

X-controlling contacts, Closed, and O,--controlling contacts Open trolled by a single slider, providing such an approach has been found to be otherwise desirable in designing the multiple pushbutton switch unit. In addition, the circuit pairs and 0, and "n and q each comprise an identical circuit switching pattern. These last mentioned circuit pairs therefore may be controlled by the same slider in a multiple pushbutton switch unit. In now applying the above-discussed general rules for designing sliders of a multiple pushbutton switch, according to the prior art practise of using all normally closed movable contact blades which are cammed open by the cam surfaces of the sliders, the slider arrangement of Table III would thus be typical for my pushbutton switch unit in order to satisfy the switching pattern described in Table I above.

In designing multiple pushbutton switch units, Table III represents what is known as a Slider Arrangement Chart. The two separate columns on the right side of Table III are often referred to as the left-right chart. To determine the slider structures and pattern for controlling the required circuits, the left-right chart is set up iirst, with circuit letter designations being arbitrarily placed in either the left or right column of this chart alongside of the slider which is to be designed to control the particular circuit. The column in which the circuit letter designation appears then denotes the direction, i.e., left or right, in which the slider is to move to cam the circuit controlling blade open.

TABLE III Typical Prior Art-Slider Arrangement Chart both appearances being alongside of slider X. This means that it has been arbitrarily determined that slider X should control circuit p by movement of slider X to the left (to cam blade 60p to its contacts open condition), and circuits 11" and "q should both be controlled by slider X by movement of slider X to the right (to cam blades clin and 6tlg to their contacts open condition). It should be recalled that circuits n and q have identical circuit switching patterns and therefore can be controlled by movement of the same slider in one particular direction, while circuit p has a switching pattern directly opposite to that of circuits n and q and therefore can be controlled by movement of slider X in a direction opposite to that direction which controls circuits n and "q. Circuits b-f, j-m, and 0, have all been arbitrarily positioned in the left-right chart of Table III in like manner, using the same procedure as described for the circuits "a, "g, "h, 11, "p, and "qf The left-right chart of Table III may then easily be used as a base for developing the remainder of a typical slider pattern and arrangement, which, according to the prior art, would effectively control the circuits ah, and j-q of Table I. For example, since circuit a is to be controlled (i.e., cammed open) by movement of slider I to the right, and circuit "a must be closed only in switch positions 5 and 7, an upper case and h have been determined as directly opposite in circuit switching pattern and therefore they may be controlled by the same slider. As a further example, it is noted that circuit "p appears in the left column and cir- Switch Positions Slider' 4 5 f 6 7 8 9 10 Left Right Ra L Ru L Ra R Ra a Lb Lb Lb Lb Lb R R b R R R R R R R c R R R R R Ld R a R R R R R R R e R R R R R R Lf j Lh Lh Rs Re Re L11 Lil h g Lm Lm Lm Lm Rio Ri Lm m jo L1 L1 Rk Rlc Ll L1 Ll l Ic LD Ln Lv Lr LD Lp Ln p nq Where,

Numerals L10-switch positions achieved by depression .of

pushbuttons of pnshrod pairs Roman numerals I-Xs1ider letters R camming movement of slider to Right aetuattes switch contact pair( s) L -carnming movement .of slider to Lent actuates switch Contact pair(s) Lower case letters a-h, and j-q-ci1'cuit designations Super-scripts (e.g., a, b, o, etw-circuit oarnmed Open by designated Right or Left movement of slider. For example, in the left-right chart, it will be noted R is positioned alongside of slider I underneath each that circuit designation a has been placed in the right switch position wherein circuit "a is to be open, to decolumn alongside of slider I. This means that it has note that movement of slider I to the right at that particubeen arbitrarily decided that slider I should be designed lar switch position cams movable contact blade 60a to control the circuit designated (1, by movement of (which controls circuit a) from its normally closed to slider I to the right, i.e., cam movable contact blade 66a its contacts open condition. To conveniently further (which controls circuit "a), to a contacts open condiillustrate on the chart of Table III that the circuit a tion by movement of slider I to the right (as viewed in is controlled by movement of slider I to the right, and FIG. 8). As a further example, it will be noted that 11'1 which switch positions this occurs, a superscript "a has circuit designation g appears in the right column and Pfhplad 1n falsed POSltlOn USO the right 0f the circuit designation "h appears in the left column, with R 1U each POSIPH Where the Clfcult conffollmg mlya: both of these designated circuits h and g being alongme Contact b1ade-1s t0 be Pam-med Open- The lette L side of slider VII. This means that it has been arbitrarily 1S placed 3 l0n-551de of Shder I nder SWltCh POSIOUS decided that slider VII should control circuit h by and 7 to-md1cate that. movement of slider I to the left to o am fr tg dcotactts, Opefn onlttlilitmftf Sles tion due to the biasing thereof. This movement of s M d as merg Orfhc l b1 d ty. t slider I to the left has not been designated to control of Sh er V: to t e ng t o Cam a le g o lis (E9n ft any of the required circuits, and therefore no superscript open condition). It should be recal ed that circuits g 70 appears to the right of the Lia alongside Slider I for the positions 5 and 7, thus indicating that movement of slider I to the left in positions 5 and 7 has no actuating eiect on any of the circuits. The full slider pattern for sliders II-VI, may then be developed in a similar manner as described for slider I.

Turning now to slider VII, it will be seen from the left-right chart, that movement of slider VII to the left has been arbitrarily selected to control circuit h. It is noted that circuit h, in accordance with the required switching pattern of Table I, is -to be opened in switch positions 4, 9, and lil. To indicate that circuit "h is to be opened by movement of slider VII to the left in these positions, an L11 Iis placed alongside of slider VII under switching positions '4, 5, 9, and 10. It will now be understood that movement of slider VII to the right occurs in the other switch positions (1, 2, 3, 6, 7, and `ii), which movement has no camming effect upon the blade controlling circuit h and thus allows it to return to its normally closed condition. Considering then lfurther Ithe use of slider VII, it is noted that in pursuance of the previously discussed general rules of slider usage, circuit g (which is opposite to circuit h in switching pattern) appears in the right column alongside of slider VII. This means that circuit g is to be controlled by movement of slider VII :to the right. An Rg is thus placed alongside of slider VII in the columns under switch positions 1, Z, 3, 6, 7, and 8. This indicates a fuliillment of the requirement in the switching pattern that movable contact blade 60g is to be cammed open in switch positions 1, 2, and 3, and 6, 7, and 8. IIn like manner, the remainder of the slider pattern and arrangement for sliders VIII, IX, `and X, has been developed by placing an R `or L alongside of each slider under the switching position in accordance with the direction (i.e., lef-t or right) that the particular slider is to be moved at that switch position :to cam the appropriate circuit controlling blade open, with the appropriate superscript appearing in a raised position just to the right of the R or L to indicate that circuit which is to be controlled by such directional movement of the particular slider in that switch position.

The typical prior art slider arrangement chart of Table III thus indicates that a minimum of ten sliders in all (sliders I-X) are necessary to satisfy the circuit requirements o-f Table I. In further analyzing the slider arrangement of Table III, it might be `considered by those skilled in the art, that the total number of circuit controlling sliders could possibly be reduced by examining the slider pattern of Table Ill to determine whether or not a combination of sliders can be used to control a particular circuit and, if so, combining such sliders to cam the controlling contact blades open. For example, circuit l (lower case L) is required to be open in pos-itions 2, `4, 5, 8, 9, and 10. Slider VII, by movement to the left, could hold circuit l open in positions 4, 5, 9, and 10, and slider VIII, by movement to the right, could control circuit l for positions 2, A8, and 9. By forming appropriate camming surfaces on sliders VII and VIII, a combination of sliders which have already been otherwise used could thus be achieved for controlling circuit 1. It should be noted, however, that it is important in combining sliders yfor controlling a circuit, that none of the -sliders which are combined may hold a circuit open in any other position (by movement of the slider in the same direction) than those which are required -for the circuit which is to be controlled by the combination. Slider VII, to the left, and slider VIII, to the right, satisfy these requirements, since slider VII moves to the left only at positions 4, 5, 9, and 10, and slider V-III moves to the right only at positions 2,3, and 9. Unless the slider satisiies such requirements, it may not be combined to control an additional circuit. Looking further for any combination of sliders which may satisfy the requirements for the complementary circuit of circuit "l, circuit k, it is noted that circuit "k is open in positions A1, 3, 6, and 7. Slider III, to the left, may be used for position 1 in controlling circuit k, and slider V to the left, may be used in position 3 for controlling circuit k, but there is no slider with a pattern suitable in positions 6 and 7 vfor controlling -circuit k. It is therefore concluded that no beneiit may be derivedby the aforementioned combination of sliders serving to control circuit 1, since its complement, circuit k, requires a separate slider, anyway, for the control thereof. It is also noted that circuits c, "d, 6, and ff having only one open position, cannot benefit by the application of such a technique. It has thus been found, therefore, that in accordance with the practice of camming one type of circuit controlling contacts open, control of the circuits listed in Table I requires ten sliders in number.

Turning now to an important aspect of my invention, which concerns the slider arrangement and pattern in my multiple pushbutton switch unit 2, I have found that by using normally open contact blades which are cammed to a closed position by the lreciprocating motion of certain of the sliders, combinations of sliders may be used in a new and improved way for controlling certain circuits. ,More specifically, in my multiple pushbutton switch unit 2, -it has thus been found that by using cammed closed movable contact blades in conjunction with the sliders required to control these blades, and also using cammed open movable contact blades which are actuated by combinations of the same sliders, the total number of sliders required to control the -various circuits outlined in Table I may be reduced Afrom ten to Iive. To explain more particularly how this has been done, attention is momentarily reverted to the Typical Prior Art Slider Arrangement Chart shown in Table III above. By omitting the sliders required to control circuits c, d, e, L k, and l (i.e., sliders III, IV, V, VI, and IX), the slider arrangement shown in Table IV may be obtained.

It should be noted `at this point that the slider pattern of Table IV provides complete mechanical interlock for the pushbutton action of my switch unit 2, since the pattern of Rs and Ls for each of the ten switching positions, is not repeated elsewhere. lIn any multiple pushbutton switch of the type exempliiied by the aforementioned Andrews Patent No. 2,431,904 which includes working surfaces cooperating with the pushrods to provide the mechanical interlock for the switch, when the pattern of Rs and Ls is different in every switch position, the switch has been provided with complete mechanical interlock for the pushbutton action.

Turning attention now back to the switching patterns of the circuits c, 61, e, and f of Table I, it should be initially noted that these circuits, which are not now controlled by yany of the sliders in Table IV, are each characterized by being open in only one switching position (e.g., circuit c is only openl in position 1).

TABLE IV Intermediate Improved Slider Arrangement Chart 13 Where,

Numerals L-switch positions achieved by depression of pushbuttons of pushrod pairs Roman numerals IX-slider letters 14 nient for my multiple pushbutton switch unit 2. The reference identification ofthe five sliders I, II, VII, VIII, and X, has now been changed to lthe upper case letters AE to represent the iinished sliders (as shown in FIG.

K Cammiug movement of slider to Right actuates 5 13) which have been constructed in accordance with my switch Contact pair(s) invention. In correlating the antecedent sliders of Table L camming movement of slider to Left actuales IV with those of Table V, it should be noted that slider Switch Contact pair) -A is derived from slider l, slider B is derived from slider Lower Case letters u h `and j qwcircuit designations II, slider C is derived -lfrom slider slider D is derived Suprscpts (e'gw a, b c etcJqCircuit cammed Open 10 from slider VII, and slider E is derived from slider VIII. by designated Right or Left movement of Slider. 4Considering `further the arrangement of Table V, it will -be noted that Rs and Ls have been used to designate y nyuuvntlon ead O f these cifcugs mali bl'demcleny directions of camming movement of the slider to the right 1. of ner as as #een previousy escri e The ower case gflcuf 1f tg bel ldpen'b More parlcufl'ay kmglst letter superscripts which appear a raised. position to ai cluiin c, w'ic mis) o e operi ogy lsl 1011 d the right of the Rs and Ls indicate the circuit which p d m'ttleme fl ;,lbn xlamnglon 1S en gli? f is cammed open by designated right or left movement of a llbialion of gis nde R, It e Purpos O( n mg 20 the slider cam surface in that particular switch position clusivel in Switch sition S1 maw in y 'e-ex' (in the same manner as'deseribed previously lfor Table tion mayy Sometimespinvolve a'll o lesgev) 81? 162g III). For example, it will be noted that at switch posi- A i Y," tion 4, for slider B, Lb appears. This designation dglylisg tfr sbgte' lfugldalsgmtlt denotes that in switch position d, movable contact blade sliders in switch position .1, it may be found that slider gleobo lll oggelglwlnem or posltlomng vnl to the left and Slider X to the right furnishes the In further analyzing Table V it will be noted that cero e s an s an are un erlined or emp asis (e.g. VIII and X in switch osition 1 with the combination of .i Rs and Ls for the saline two sliders in all of the other ERM .for shder C. m Position 1) Thls def'slgnauqn (if nine switching positions besides switching position i it imderhned superscnpts Indicates. that a pamcular-c1rcult Should be nted that the same combination as provied Iidentified by the letter designation that is underlined or at switching position i1 does not @appear It may thus subscored is allowed to open by right or left movement be established that when slider VIH mov'es to the right of associated slider cam surfaces on two or more sliders or slider X moves to the left, movement of these sliders m thzt Sytvlltch osmon qrnlsthne. astregolsly in their predetermined respective directions will cam mo-'vcusie. 1 as .een ascer ai e. a m .e rs SW1 C able contact blade `60e to a contacts closed condition. posltlonfwhen Shder. C (denva'tive from shder x) moves It will thus be seen, that the only switch position in which to the right and Shder E .(demvauve. from .shder VIII) movable contact blade y60C may move to its contacts open movs to Fhe iefti in Xduslve Pattern 1S Obtamed for con' `condition is in the rst position. 'In all the other switch 10 troumg C11-cult C (l'ej allowmg blade we to Opern' positions, blade 60e is cammed to a contacts closed con- The subscofd supescnpt'g thus @pears tf) the left of dition by the sliders vin and X. To iiiusi-rate in tabuiar the R for Slldef C 1110 SWltCh POSIQOH 1 (Le-i ERfq l, form the manner in which combinations of sliders may afld also t0 the left 0T the L fol' Slldef E at POSlflOn 1 be used to control the imuits cj dj e L kj (i.e., C kLm), to indicate the controlling functions of and "1, attention is now directed to Table V. these sliders.

TABLE V Slider Arrangement Chart 0f My Switch Unit Switch Positions slider i 2 3 4 5 6 7 8 9 1o Left Right Ra R R L- Ru L- R RH Ri a Lb 3R* Lb Lb Lb Lb Lb dR fR def b C Rw RM1 Lv Lv Lv Lv Lv LD Lv Lv gp ngi D R1 Re me Lhl Lhl R kRz Rz Lhl fLhl @nl l E grim Rua Lm Lm Lm kLm gLm R510 Rim Lm gm ,engl

Where, Turning now to the left-right chart of Table V, it

Closed which is allowed to open by designated Right or Left movement of slider.

Table V represents a tabulation of the slider arrangewill be noted that the subscored superscript g now makes an appearance there, in the left column-alongside of slider C, and in the right column-alongside of slider E. vThis indicates that the combination of sliders C and E is being used to cam blade 66e closed by movement of slider C to the left, and by movement of slider E to the right. The positioning of the enclosed lower case letters in the left and right columns of Table V respectively thus indicates that the `circuits identified by these letters are cammed closed by right or left movement of the associated slider cam suriface(s) in the manner designated.

Continuing further with a description of my improved means `for reducingr the number of sliders required to control the circuits of Table l, it will be noted that circuit d thereof is -characterized by having its contacts open only in position 9. In analyzing the R and L pattern for switch position 9, a combination of Rs and Ls that occurs only in switch position 9' is then sought in the same manner .as previously described for circuit 0. Such an analysis indicates that slider B, to the right, and slider E, to the right, will furnish the desired exclusive pattern. It is then established that slider B, to the left, and slider E, to the left, will cam movable contact blade 60d to a closed circuit condition. To represent this determination, the subscored superscript Q appears to the left of the R for sliders B and E in switch position 9. The subscored lower case letter Q is also placed in the left column of the left-right chart of Table V opposite the sliders B and E respectively, to indicate that movement of sliders B and E to the left will cam blade 60d to a closed circuit condition (-Which occurs in all switch positions except position 9).

Turning now to circuit e, it is noted from Table I that circuit e is open only in switch position 3. An examination of the R and L slider pattern Ifor the i-ve sliders is then again made in search of a combination of Rs and Ls that occurs only in the third position. It is found that slider B, to the right, slider C, to the left, and slider D, to the right, -furnishes the desired exclusive pattern. It is thus established that slider B, to the left, slider C, to the right, and slider D, to the left, will cam movable contact blade 60e closed. To indicate the fact that sliders B, C, and D, have been chosen for controlling circuit e in this manner, the underlined superscript e has been placed to the left of the R of slider B, the L of slider C, and the R of slider D, all of Which appear in switch position 3 of Table V. To further indicate the arrangement of sliders B, C, and D for maintaining circuit e closed in all other positions except position 3, the subscored lower case letter e is placed in the left column alongside of slider B, in the right column alongside of slider C, and in the left column alongside of slider C.

Considering now circuit J2 and referring again to Table I, it is noted that circuit f is open only in switch position x10. By examining the R and L slider pattern tor the sliders for the purpose of iinding a combination of Ls and Rs that `occurs only in position 10, it is found that slider B, to the right, slider D, to the left, and slider E, to the left, furnishes the desired exclusive pattern. It is thus established that, movement of slider B', to the left, slider D, to the right, and slider E, to the right, Will cam movable contact blade 60f closed. that the only position in which circuit f may be opened is in the tenth position. To indicate this on Table V, the subscored superscript i appears under switch position 10 to the left of the R of slider B, the L of slider D, and the L of slider E. To further indicate on the leftright chart that circuit is to be cammed closed by the movements of slider B to the left, and slides D and E, to the right, the subscored lower case letter f is placed in the left column alongside of slider B and in the right Kcolumn alongside of sliders D and E, respectively.

In now rendering further consideration to circuits k iand l (as `outlined in Table I), an `analysis has previously been made of the pattern tor circuit 1. This previous :analysis of circuit l indicated that this circuit is open rin positions 2, l4, 5, 8, 9, and 10, and that trom Table "III, slider VII, to the left, could hold it open in positions `4, 5, 9, `and 10, and slider VIII, to the right, could perform this function for positions 2, 8, land 9. The =R and L patterns of sliders D and E (Table V) are derivative respectively trom sliders VII and VIII (Table III), Iand therefore the sliders D and E may be combined in the same manner to control circuit "l. While it was decided that the sliders VII and VfIII lof Table -III could be used in such combined fashion to control circuit 1, it was also found that by using the prior art approach, no combination could be obtained which would satisfy the requirements of the complementary circuit k. By applying my invention, in analyzing circuit k, for the purpose of nd- It is obvious then ring a combination of sliders that would open circuit k in positions 1, 3, 6, 'and 7 (viewing Table I), an exclusive pattern may be found. By studying the yR yand L slider pattern of 'Ilable V, it is found ythat slider D, to the right, and slider E, -to the left, provide an exclusive combination which appears only in the switch positions 1, 3, 6, and 7, and in no other switching positions. Thus, the complementary circuits "k and l may each be controlled by combining the sliders D and E. To illustrate that circuit "l is to be cammed open in positions 4, 5, 9, and 111 by slider D, the plain superscript l is placed to the right of the L in these switch positions in Table V (alongside yof slider D) 'and it is also placed to the right of the R appearing in switch positions 2, 8, and 9 (alongside of slider E), :to indicate the controlling function for sliders D and E. In the same manner previously described for circuits cammed open, appropriate entries have also been made in the left-right chart of 'Iable V to indicate the `direction of movement of sliders D land lE to control circuit 1. To illustrate in Table V the controlling lfunctions of sliders -D and E for circuit "k (which is cammed closed), the subscored supe-rscript E is placed to the left of the R alongside of slider D in positions 1, 3, `6, and 7, Iand to the ileft of the L alongside of slider E in positions 1, 3, 5, and 7. The underlined lower case circuit letter 1 0 has also been placed in the left column ,alongside of slider D and in the right column alongside of slider E to indicate that movement of slider D to the left `and movement of slider E to the right will keep circuit k cammed closed in all of the switching positions except 1, 3, 6, and 7.

It will thus be seen that by virtue of my invention, there has been provided ian improved multiple pushbutton switch unit 2 having an eicient means for controlli-ng the circuits a-h, iand j-"q (16 circuits in all) by means of only tive sliders. This result has been obtained by the use of movabie contact blades which are cammed closed by certain sliders in some of the switch positions and allowed to open by movement of yan exclusive combination of sliders in `other switch positions. It will be obvious to those skilled in the art that numerous other combinations and arrangements of slider patterns might be obtained using the same principles 'and structure which I have heretofore described, with equally beneficial results.

Turning now to la further explanation of my multiple pushbutton switch unit 2, it will be noted that `as shown in FIG. 13, I have `also included two other sliders F `and G. Slider F is designed to serve as a detent, or pushrod controlling slider and -slider G has been constructed to co'- `operate with `detent sliderrF and to serve as a momentary fand button return slider for the switch unit. More particularly, as shown in VFIG. 13, detent slider F includes a series `of spaced specially constructed Working recesses 121 extending inwardly trom its upper edge 122 land momentary .slider G includes [a series of spaced recesses 123 rwhich are identical in configuration to recesses i121 but are ydisposed in a reverse longitudinal direction. The sliders F and G ,also have longitudinally extending projections 124 Iand 126 (as shown in FIG. 13) which receive one en'd `of .associated compression springs 12B and 136i. The other end of each compression spring 128 and 130 is supported by transverse bracket 132 which is positioned athwart and adjacent the closed end of base l8 to continuously bias both lof the sliders -F and G to the right (las shown in FIG. 8).

To facilitate an understanding of the operation of the detent yand momentary sliders F 'and G respectively, fattention is drawn -to FIG. 14. The detent slider F and the momentary slider G are both there shown in fragmentary view, with the momentary slider G being positioned in front of the `detent slider F. lFor purposes of illustration, the pairs of pushrods 41 and 50 are da-granmiatically shown, with the pushbutton `62 that controls the pushrods 41 being in an intermediate ldepressed actuating position. With pushrods 411 in the position shown in F-IG. 14, pushrods 54), which would be located at the other end of the switch are, of course, held in their outermost position by means of the biasing effect of `associated spring 66 (as shown in FIG. 2) on the controlling pushbutton. In addition to the outward biasing force `of spring 66, however, angular edge sections 121a of adjacent recesses 121 of the detent slider F :also engage the actuating portions 5 6 of the two pushrods l50 to urge them or cam them toward their uppermost positions by means of the spring biasing force applied by compression spring 12S to slider F. (See FIG. 8.)

When pushbutton 62 controlling pushrods Stl is depressed (i.e., moved from its position shown in FIG. 14 to its position shown in PIG. 15), the biasing force to the right applied to slider F by compression spring 128, initially provides a resisting force to the depression of the pushrods by means of the engagement of angular sections 121a of the two recesses 121 which are associated with the pushrods 50l with their pushrod actuating portions 56. This resisting force provides an eicient means ttor controlling these pushrods during their initial downward movement. When the pushrods 541i' .are `further depressed, as shown in FIG. 15, the compressive force applied to detent slider F by compression spring 1128 is overcome by the manual pressure exerted upon the controlling pushbutton 62. Slider F is then moved to the left, to the position where it is shown in FIG. 15. As p-ushrods 50 are then depressed further toward their extreme depressed position, as shown in FIG. 16, actuating portions 56 pass points 12111 of the slider F. Slider F thus snaps to the right due to the force of spring 1128 to its position as shown in PIG. 161. When pushrods 5% move from their position in FIG. 15 tothe extreme depressed position of FIG. 16, actuating portions 56 .thereof also cam momentary slider G to the left momentarily from its position as shown in FIG. 15, to hold slider G against the :compressive biasing force of its spring 130 in the position shown in FIG. 16. When pushrods 5G are in their extreme depressed position, as shown in FIG. 16, rods 41 have then been moved back to their outermost position and the camming section r of slider G moves to the left to allow normally closed movable contact blade 6dr to make contact with its mating iixed contact. When the pressure exerted `upon pushrodsV 5t)` is then released, momentary` slider G moves back to the right, to the position shown in FIG. 17, thus forcing the pushrods 50 outwardly to where they are shown by `angular sections 123C. Pushrods 50- are then in their intermediate contact actuating position and are locked in that position by means of curved points 12119 of the recesses of detent slider F.

It will thus be seen that the cooperation between the detent slider F and the momentary slider G of my multiple pushbutton switch unit 2 provides for eficient control of Ithe movement of the pairs of pushrods i1-Stii during the reciprocation thereof between their depressed and outer (normal) positions. In addition, momentary slider G is an eliicient means for returning depressed pushrods to their outer (normal) positions while at the same time providing momentary contact action for movable contact blade `6th' during the depression of any pair of pushrods. The particular construction of sliders F and G and fthe biasing arrangement for them in my switch comprises the invention `of Stewart A. Woodward and this construction and arrangement are described :and claimed in his aforesaid copending application Serial No. 42,815.

Turning now to a further explanation of the operational aspects of my multiple pushbutton switch unit 2, to il- -lfustrate the operation of a typical movable contact blade which is cammed open, I have chosen bl-ade 60a, which is controlled by slider A. FIG. 18 shows the pushrods 41 diagrammatically as they are positioned with respect to their associated working surfaces 1 of slider A when the pushrods 41 are maintained in their intermediate depressed actuating position. For purposes of simplification, a section of only slider A has been shown in FIG. 18, since slider A is eiiectively responsible tor the actuation cam surfaces.

of lthe movable contact blade sila. When slider A is in this position, an outwardly extending section oi the camming surface A-a overlies movable contact blade dita, as shown in FIG. 18, and holds it open from engagement with its mating iixed contact against the normally closed biasing force of blade 60a. When pushrods 41 are in their intermediate depressed position (as shown in FiG. 18), pushrods i5 are in their outer or uppermost position with respect to the working surfaces 5 of slider A. When pushrods 45 are then depressed to their position in FIG. =19, they engage the diagonal edges of the working surfaces 5 to move slider A to the left. Movement of the entire slider A thus occurs, and the diagonal edges of working surfaces 1 of slider A engage the pushrod actuating portions 56 of pushrods 41 to move pushrods 41 back to their uppermost position (as shown in FIG. 19). Movable contact blade 6de thus enters an inwardly extending recess section a of cam surface A-a and is allowed to close upon its mating xed Contact (not shown). All of the other movable contact blades of my switch -uni't 2 which are cammed open `are operated in a similar manner to that described for the pushrods d1.

Considering now the operation of the movable contact blades of my switch unit 2 which are cammed to a contacts closed position, in FIG. 2G, the sliders C and E are represented in fragmentary fashion, along with blade 69C. The sliders C and E have been previously selected for controlling movable contact blade 6de, which is to be open only in position 1. With pushrods 42 thus depressed, as schematically represented in FIG. 20, the left ends oi' the sliders C and IE are adjacent, and an outwardly extending section of cam surface E-c (of slider E) holds or cams movable Contact blade 6de to a contacts closed position in engagement with its associated fixed contact.

When pushrods 41 in FIG. 20 are depressed to their intermediate actuating position shown in FIG. 2l, slider E lis moved to the left by means of the engagement of actuating portions S6 of the pushrods 41 with the diagonal working surfaces 1 of slider E. Movement of slider E to the left, to the position in which it is shown in FIG. 2l lalso causes pushrods 42 to be moved outwardly by means of the coaction of diagonal working surfaces 2 of slider E therewith. The cam .surface E-c also moves to the left so that it cooperates with cam surface C-c to form an aligned recess which allows movable Contact blade @c to move upwardly by its spring biasing force to open the pair of contacts controlling circuit c. It should be noted at this point, that the only position in which cam surfaces C-c and E-c may cooperate to allow movabie Contact blade dile to open is in switching position 1. The reason for this, as previously described, is that only in switch position 1 will this particular combination of movements by sliders C and E occur.

FIG. 22 illustrates the relative positions of sliders B, C, and D, when pushrods i3 are depressed. It will be recalled that sliders B, C, and D have been designated to control circuit e by camming movable Contact blade 6de open in position 3. In FIG. 22, slider B is positioned in the foreground, slider C is positioned behind it, and slider D is positioned in the background behind slider C. When pushrods 43 are depressed, the cam surfaces B-e, C-e, and D-e (as shown in FIG. 13), cooperate to allow movable contact blade title to move into an over-all aligned recess provided by the cooperation of these three When movable contact blade diie moves into this indented recess, it opens circuit e. In all other positions besides switch position 3, the combination of movements of sliders B, C, and D, which is obtained in position 3 is not achieved, and therefore, movable contact blade @tlc is cammed into closed engagement with its associated xed contact in the same manner as previously described.

FIG. 23 illustrates diagrammatically the circuit arrangement of the terminals of switch 2. Only the terminals which are to be connected to external leads have been identified byy reference numerals in this figure. It will be understood by those skilled in the art that the arrangement of the various terminals and the selection of external bridges 144i (FlG. 2) have provided this switch circuit configuration. Blade dits is a dummy blade in switch 2, since it is not actuated.

It will now therefore be seen that my new and improved multiple pushbutton switch unit 2, as herein illustrated, provides an efiicient and advantageous means for controlling a large number of circuits. lt should be realized that by combining sliders in the manner that I have disclosed, numerous other arrangements of sliders may be obtained for controlling circuits having various switching requirements. Further, it may be preferable to utilize any number of combinations of sliders in accordance with the circuit requirements which are to be satisfied by a particular multiple pushbutton switching unit. It should therefore be realized that certain aspects of my invention may be incorporated efficiently and beneficially in other various types of pushbutton switch applications.

While in accordance with the patent statutes I have described what at present is considered to be the preferred embodiment of my invention, it will be obvious to those skilled in the art that various changes and modifications may be made therein without departing from my invention and I therefore aim in the following claims to cover all such equivalent variations as fall within the true spirit and scope of this invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

l. A multiple pushbutton switch unit for controlling a plurality of circuits comprising a plurality of manually depressible actuators, a predetermined number of longitudinally movable sliders engaged and operated by said actuators, the surfaces of said sliders engaged by saidactuators being slanted both for operation by said actuators and for controlling the position of said actuators relative to each other, a plurality of switch arms biased in one direction toward a normal position and being movable by said sliders against their biasing to a second position, first fixed contact means engageable respectively by selected ones of said switch arms when said switch arms are in said normal position, thereby to form a plurality of normally closed switches, and second fixed contact means engageable respectively by at least one other of said switch arms when said other arm is in said second position, thereby to form at least one normally open switch and increase the circuit controlling flexibility of said switch unit without increasing the number of said sliders, said switch arm of one of the switches engaging at least two of said sliders and being actuated by the conjoint action thereof.

2. A multiple pushbutton switch unit for controlling a plurality of circuits comprising a hollow housing, a plurality of manually depressible actuators extending into said housing through a wall thereof, a predetermined number of longitudinally movable elongated sliders arranged in side-by-side relationship within said housing, each slider having a series of diagonal working surfaces generally in alignment with and distinct from working surfaces in the other sliders, each actuator having an inner portion extending transversely through an aligned group` of working surfaces of the sliders to move the sliders to predetermined contact controlling positions, said working surfaces of said sliders being diagonally slanted both for operation by the associated actuators and for controlling the position of said actuators relative to each other, a plurality of switch arms biased in one direction toward a normal position and being movable by said sliders against their biasing to a second position, first fixed contact means engageable respectively by selected ones of said switch arms when said switch arms are in said normal position, thereby to form a plurality of normally closed switches, and second fixed contact means engageswitch arm engaging and being actuated by the conjoint Y action of cam surfaces on at least two of said sliders,

and each of said last mentioned sliders having at least one additional cam surface engaging and actuating the switch arm of one of said normally closed switches whereby said p last mentioned sliders operate said normally open switch simultaneously with at least one of said normally closed switches.

3. A multiple pushbutton switch unit for controlling a plurality of circuits comprising a hollow housing, a plurality of adjacent pairs of manually depressible actuatorsV extending into said housing through a wall thereof, a predetermined number of longitudinally movable elongated sliders arranged in side-by-side relationship within said housing, each slider having a series of adjacent pairs of A coincident diagonal working surfaces generallyin alignment with and distinct from adjacent pairs of coincident diagonal working surfaces in the other sliders, each actuator having an inner portion extending transversely through an aligned group of working surfaces of the sliders, a pushbutton attached to the outer ends of each pair of said actuators to move the sliders to predetermined contact controlling positions by depression in unison of each pair of actuators, said diagonal working surfaces engaging said actuators for operation thereby and for returning each previously depressed pushbutton to its outermost position upon subsequent depression of another pushbutton, a plurality of switch arms all biased in one direction toward a normal position and being movable by said sliders against their biasing to a second position,` first fixed contact means engageable respectively by selected ones of said switch arms when said switch arms are in said normal position, thereby to form a plurality of normally closed switches, and second fixed contact means engageable respectively by at least one other of said switch arms when said other arm is in said second position, thereby to form at least one normally open switch and increase the circuit controlling flexibility of said switch without increasing the` number of said sliders, said one other switch arm engaging and being actuated by the conjoint action of cam surfaces on at least two of said sliders, and each of said last mentioned sliders having at least one additional cam surface engaging and actuating the switch arm of one of said normally closed switches whereby said last mentioned sliders operate said normally open switch concurrently with at least one of said normally closed switches.

4. A multiple pushbutton switch unit for controlling a plurality of circuits comprising a plurality of manually depressible actuators, a predetermined number of longitudinally movable sliders engaged and operated by said actuators, the surfaces of said sliders engaged by said actuators being slanted both for operation by said actuators and for controlling the positioning of said actuators relative to each other, a plurality of switch arms all biased in one direction toward a normal position and being movable by said sliders against their biasing to a second position, first fixed contact means engageable respectively by selected ones of said switch arms when said switch arms are in said normal position thereby to form a plurality of normally closed switches which are cammed open, and second fixed Contact means engageable respectively by at least one other of said switch arms when said other arm is in said second position thereby to form at least one normally open switch which is cammed closed to increase the circuit controlling iiexibility of said switch without increasing the number of said sliders, one of the switch arms engaging and being actuated by the conjoint action of cam surfaces on at least two of said sliders, and each of said last mentioned sliders having at least one additional cam surface engaging and actuating the switch arm of another of said switches concurrently with said one switch arm.

5. The switch unit of claim 1 wherein the normally open switch is opened upon the depression of an associated one of said actuators but remains closed upon the depression of all of said other actuators.

6. A multiple pushbutton switch unit for controlling a plurality of circuits by movement of switch arms where at least one of said switch arms is in engagement with its mating fixed contact in more than half of the switch positions and is open in less than half of the switch positions, said unit comprising a plurality of manually depressible actuators, a predetermined number of longitudinally movable sliders engaged and operated by said actuators, the surface of said sliders engaged by said actuators being diagonally slanted both for operation by said actuators and for controlling the positioning of said actuators relative to each other, a plurality of contact supporting switch arms all biased in one direction toward a normal position, certain of said sliders being arranged to cam a first group of said switch arms against their biasing force to a second position, a plurality of said sliders having cam surfaces cooperating to cam at least one other of said switch arms against its biasing force to said second position, first fixed contact means engageable respectively by the first group of switch arms when said switch arms are in the normal position, thereby to form a plurality of normally closed switches, and second fixed contact means engageable by said one other switch arm when said other arm is in its second position, thereby to form at least one normally open switch and increase the circuit controlling flexibility of said switch unit without increasing the number of said sliders, said plurality of sliders having cam surfaces cooperating to cam said one other switch arm each having additional cam surfaces for camming at least one of said first group of switch arms, whereby said normally open switch is operated concurrently with at least one of said normally closed switches.

7. The switch unit of claim 4 wherein the normally open switch is opened upon the depression of an associated one of said actuators but remains closed upon the depression of all of said other actuators.

8. A multiple pushbutton switch unit for controlling a plurality of circuits comprising a hollow housing, a plurality of manually depressible actuators extending into said housing through a wall thereof, a predetermined number of longitudinally movable elongated sliders arranged in side-by-side relationship within said housing, each slider having a series of diagonal working surfaces generally in alignment with and distinct from working surfaces in the other sliders, each actuator having an inner portion extending transversely through an aligned group of working surfaces of the sliders to move the sliders to predetermined contact controlling positions, said working surfaces of said sliders being diagonally slanted both for operation by the associated actuators and for controlling the position of said actuators relative to each other, a plurality of switch arms biased in one direction toward a normal position and being movable by said sliders against their biasing to a second position, first fixed contact means engageable respectively by selected ones of said switch arms when said switch arms are in said normal position, thereby to form a plurality of normally closed switches, and second fixed contact means engageable respectively by at least one other of said switch arms when said other arm is in said second position, thereby to form at least one normally open switch and increase the circuit controlling flexibility of said switch without increasing the number of said sliders, said second xed contact means comprising at least one flexible contact member that is generally V-shaped and has a curved free end which engages a mating switch arm, said one other switch arm engaging and being actuated by the conjoint action of cam surfaces on at least two of said sliders, and each,

of said last mentioned sliders having at least one addiswitches.

9. The switch unit of claim 6 wherein the second fixed contact means comprises at least one flexible contact member, said member being generally V-shaped and comprising a supporting portion with a slot formed therein to receive cooperating fingers of a supporting terminal blade, and a fiexible contact portion bent over angularly from said supporting portion and having a curved free end which engages a mating switch arm.

10. In a pushbutton switch, a housing, a plurality of actuators extending into said housing, a plurality of longitudinally movable sliders arranged side by side in said housing transversely of said actuators and having working surfaces on their upper edges engaging said actuators for actuation thereby, said sliders having cam surfaces formed on their lower edges, a plurality of switch arms biased to a normal position against said cam surfaces and being movable by said sliders against the bias to a second position, said switch arms being movable in a plane transverse to that of said sliders, and a fixed contact means positioned beneath and engageable by one of said switch arms to form a normally open switch therewith, said fixed contact means comprising a fiexible electric contact for a switch, said contact being of thin blade construction and comprising a fiat supporting portion with a slot formed therein for engagement with a supporting terminal, and a flexible contact portion extending angularly from one end of said supporting portion and having a curved free end which serves as a contact surface for engaging said one switch arm.

11. A multiple pushbutton switch unit for controlling a plurality of circuits comprising a hollow housing, a plurality of manually depressible actuators extending into said housing through a wall thereof, a predetermined number of longitudinally movable elongated sliders arranged in side-by-side relationship within said housing, each slider having a series of diagonal working surfaces generally in alignment with and distinct from working surfaces in the other sliders, each actuator having an inner portion extending transversely through an aligned group of working surfaces of the sliders to move the sliders to predetermined contact controlling positions, said diagonal working surfaces engaging said actuators for operation thereby and for controlling the positioning of said actuators relative to each other, a plurality of switch arms all biased in one direction toward said actuators to a normal position, certain of said sliders being arranged to move longitudinally in first or second opposite directions to cam a first group of said switch arms against their biasing force away from said actuators to a depressed actuating position, a plurality of said sliders having an exclusive pattern of longitudinal movement in said first and/or second directions responsive to the movement of one of said actuators to its depressed actuating position, said plurality of said sliders having cammed surfaces cooperating with each other for camming at least one other of said switch arms against its biasing force to a depressed actuating position, first fixed contact means engageable respectively by the first group of switch arms when said switch arms are in the normal position, thereby to form a plurality of normally closed switches, and second fixed contact means engageable by said one other switch arm when said other arm is in its depressed actuating position, thereby to form at least one normally open switch and increase the circuit controlling flexibility of said switch unit without increasing the number of said sliders, said plurality of sliders having cam surfaces cooperating to cam said one other switch arm each having additional cam surfaces for camming at least one of said first group of switch arms, whereby said normally open switch is References Cited in the file of this patent UNITED STATES PATENTS Porter Apr. 22, 1902 Z4 Andrews Dec. 2, 1947 Williams Aug. 28, 1951 Batcheller Apr. 7, 1953 Batcheller Sept. 15, 1953 Dumke et al. Apr. 15, 1958 Vermeulen Mar. 17, 1959 Deighton Sept. 20, 1960

Claims (1)

1. A MULTIPLE PUSHBUTTON SWITCH UNIT FOR CONTROLLING A PLURALITY OF CIRCUITS COMPRISING A PLURALITY OF MANUALLY DEPRESSIBLE ACTUATORS, A PREDETERMINED NUMBER OF LONGITUDINALLY MOVABLE SLIDERS ENGAGED AND OPERATED BY SAID ACTUATORS, THE SURFACES OF SAID SLIDERS ENGAGED BY SAID ACTUATORS BEING SLANTED BOTH FOR OPERATION BY SAID ACTUATORS AND FOR CONTROLLING THE POSITION OF SAID ACTUATORS RELATIVE TO EACH OTHER, A PLURALITY OF SWITCH ARMS BIASED IN ONE DIRECTION TOWARD A NORMAL POSITION AND BEING MOVABLE BY SAID SLIDERS AGAINST THEIR BIASING TO A SECOND POSITION, FIRST FIXED CONTACT MEANS ENGAGEABLE RESPECTIVELY BY SELECTED ONES OF SAID SWITCH ARMS WHEN SAID SWITCH ARMS ARE IN SAID NORMAL POSITION, THEREBY TO FORM A PLURALITY OF NORMALLY CLOSED SWITCHES, AND SECOND FIXED CONTACT MEANS ENGAGEABLE RESPECTIVELY BY AT LEAST ONE OTHER OF SAID SWITCH ARMS WHEN SAID OTHER ARM IS IN SAID SECOND

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