US2968704A - Pushbutton switch with spring loaded slider - Google Patents

Description

Jan. 17, 1961 s A. WOODWARD ETAL 2,968,704

PUSHBUTTON SWITCH WITH SPRING LOADED SLIDER Filed June 2'7, 1958 FIG. I.

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b3 MAJ of @A 43 The? Arrovneg United States Patent PUSHBUTTON SWITCH WITH SPRING LOADED SLIDER Stewart A. Woodward, Stratford, and Sam M. Golden, Fairfield, Conn., assignors to General Electric Company, a corporation of New York Filed June 27, 1958, Ser. No. 744,979

3 Claims. (Cl. 20018) The present invention relates to an electrical switch and particularly a multiple pushbutton switch having a series of manually operated pushbuttons which are individually operated to provide selective circuits for a variable load such as electric ranges, room and commercial air conditioners, washing machines, electric broilers and window fans. The basic patent for such multiple pushbutton switches is the Andrews Patent No. 2,431,904, which is assigned to the same assignee as is the present invention.

Many desirable improvements have been added to pushbutton switches over the years. For example: A detent action can be provided for each of the buttons so that a given circuit cannot be opened and then immediately reclosed, which would be a serious fault if the switch were installed with air conditioning equipment, as explained in the Hutt Patent No. 2,723,317. Another improvement would include a momentary contact action for one of the pushbuttons when the switch is used for the control of solenoids or for starting fluorescent lamps. A third improvement would be the feature whereby the OFF button of the switch is always returned to its outermost position immediately after it is depressed and released. When the switches are used on electric ranges, the buttons will all be in the outermost position when the range is not being used, thus improving the over-all appearance of the appliance.

The principal object of the invention is to provide a pushbutton switch with a spring loaded slider that may perform one of several functions; namely, the function of a detent slider, a button-return slider or a momentary contact slider.

A further object of this invention is to provide a multiple pushbutton switch with an additional elongated slider that is spring loaded at one end to give the switch one of several variations such as a detent action, a buttonreturn action or a momentary contact action.

The present invention represents an addition to the standard models of pushbutton switches. The advantages of this invention can be obtained by merely adding another slider that is spring loaded at one end so that this slider will always return to its original position once manual pressure is released from all of the buttons. Different types of action can be obtained from this additional slider by adopting one of several types of inclined surfaces on the slider that either lock a depressed button in the down position or return a depressed button to its outermost position when manual pressure is released. Our invention will be better understood from the following description taken in connection with the accompanying drawing and its scope will be pointed out in the appended claims.

Figure 1 is a front view of a six position pushbutton switch embodying the present invention.

Figure 2 is a bottom plan view of the switch of Figure 1 with the bottom cover removed to show the inner workings of the switch mechanism and particularly the coiled spring at the right end of the housing bearing against the end of a particular slider in a series of five elongated sliders assembled in the switch.

Figure 3 is a layout view of the five sliders of the switch shown in Figure 2 with particular emphasis given to the second slider from the top which is the additional slider that provides a button-return action.

Figure 4 is a similar layout view showing a group of four sliders where the second slider from the top is the additional slider that provides a detent action for all of the buttons of the switch.

Figure 5 is a showing of a second modification of the additional spring loaded slider and it is closely related to Figure 3 providing for the return of two buttons upon the release of manual pressure.

Figure 6 is a third modification of the spring loaded slider where one edge of the slider is undercut to provide cam surfaces for cooperation with the movable contacts of the switch, so that the right-hand end button has momentary contact action.

Figure 7 is a diagrammatic showing of the action of a flat column spring that assumes an S-shape and is a substitute for the coiled spring of Figure 2.

Referring in detail to the drawing and in particular to Figure 1, 10 represents a hollow switch housing formed by a recessed base member 11 of suitable molded insulating material and a thin bottom cover plate (not shown) as is well-known in this art. The switch shown in Figure 1 happens to be a six position switch with six push rods 12 that extend through suitable openings in the top wall of the base 11 for cooperation with the elongated sliders shown in the layout views of Figures 3-6. The terminals of the contacts of the switch extend downwardly from the bottom of the base 11. The line terminals 13, 14 and 15 are disposed at one side of the base while the load terminals 16, 17, 18 and 19 are arranged on the opposite side of the base, as will be understood from a study of the bottom plan view of Figure 2. Cantilever spring blades 20, which serve as the movable contacts of the switch, are fixed at one end to one of the load terminals 16-19, while the opposite end of each blade is capable of movement toward and away from the fixed contacts of line terminals 13-15.

The central portion 25 of the base 11 that extends longitudinally thereof provides a relatively deep recess 26 for the reception of a stack 27 of elongated sliders of insulating material that are acted upon by the push rods 12 and are shifted to control the positions of the movable contacts 20 of the switch. A better understanding of these sliders 27 may be had by referring to the layout view of Figure 3 wherein the five sliders that make up the stack 27 are shown in detail. For identification purposes, these sliders are numbered 28-32. At the outset it should be recognized that sliders 28 and 30-32 are standard sliders and that this invention relates to the additional slider 29 that is spring loaded at one end by means of spring 33 shown at the right end. It should also be understood that all of the sliders illustrated in the drawing are positioned bottom-side-up for purposes of illustration. Looking at slider 28, its uppermost edge 34 is undercut to form cam surfaces 35 which are adaptedto engage the central portion of the movable contact blades 20 of the switch so as to open or close the various circuits through the blades. The lowermost edge 36 of the slider 28 is provided with a series of inclined surfaces 37 which are engaged by the innermost ends of the push rods 12 for shifting the slider back and forth in the recess 26 of the switch base 11. Comparing are engaged by the push rods 12. While we have chosen to illustrate the inclined surfaces 37 as portions of open notches in one edge of the slider, it will be understood that they also could be formed by stamping triangular holes in the sliders. Likewise, the inclined surfaces could be on the same edge of the sliders that contains the cam surfaces for actuating the blades.

Particular attention will now be given to the additional slider 29 that is spring loaded at the right end to retain the slider in a normal or original position toward the left-hand side of the base 11. The uppermost edge 39 of the slider is undercut as at 40, but no cam surfaces are included so that this slider will not engage any of the movable contact blades 20. Furthermore, the lowermost edge 41 of the slider 29 is notched but five of the notches are merely clearance notches 42 of generally square shape which provide no interference with the innermost ends of the push rods 12. However, the notch at the right end of the slider has an inclined surface 43 so that when the related push rod is depressed, it will shift the slider 29 to the right against the spring 33. It should be understood that the depression of this righthand push rod or button has not only shifted slider 29 but also sliders 23 and 3t) and in so doing, the cam surfaces 35 will operate certain of the contact blades 20. When manual pressure is released from that push rod, the compression spring 33 will expand and return the slider 29 to its original or normal position, thereby returning the push rod to its outermost position. Hence, this additional slider 29 may be classified as a button-return slider.

Figure 4 shows a first modification of the additional slider 29 of Figure 3. This additional slider of Figure 4 is slider 49, and there are three standard sliders 48, 50 and 51. As in the sliders of Figure 3, each of the standard sliders have cam surfaces 35 on their uppermost edge and inclined surfaces 37 on the lowermost edge. Again the additional slider 49 has a compression spring 33 normally biasing the slider to the extreme left position. The uppermost edge 52 of the slider is deeply undercut so that no cam surfaces are provided that might act upon the contact blades 2%. The lowermost edge 53 of the slider 49 is provided with a series of notches each with a doubly inclined latching portion 54 for each push rod 12 of a button. Attention is directed to the fact that the switch of Figure 4 would have only five push rods rather than the six used in Figure l of the first modification. Accordingly, when a push rod is depressed, its innermost end will engage an outer inclined section of the latching portion 54 and force the slider to move against the action of the spring 33. After the push rod passes the center of its inward movement, an inner reverse inclination 55 of the latching portion will cause the slider to move behind the push rod in the manner of a latch and temporarily lock the push rod in the down position. This additional slider 49 may be classified as a detent slider in that it increases the resistance to the changing of the positions of the push rods. For example: With one push rod in the depressed position, pressure exerted against another button will cause it to move inwardly of the switch housing forcing the slider 49 against the spring 33. As the slider 49 moves, it will likewise unlatch the push. rod in the down position. enabling it to move outwardly.

The second modification of this invention is illustrated in Figure 5, showing merely the additional slider 59 that is spring loaded at its right end by the compression spring 33. This slider is closely related to slider 29 of Figure 3 in that it is a button-return slider. It differs from slider 29 in that it has two inclined surfaces 43 for returning two buttons once manual pressure is released.

Figure 6 is a third modification of the additional slider and it is identified as 69. The same compression spring 33 bears against the right end of the slider and normally biases the slider to the extreme left position.

This slider 69 is also similar to slider 29 of the first modification in that it has a single inclined surface 43. Slider 69 differs from slider 29 in that it includes cam surfaces 35 adjacent the uppermost edge of the slider for cooperation with the movable contact blades 20. This arrangement classifies this slider 69 as a momentary contact slider because the extreme right-hand button is not only returned to its original position when manual pressure is released, but the slider actuates one or more circuits through the switch for controlling fluorescent lamps or solenoids and the like.

Having described above our invention of a novel slider construction for a multiple pushbutton switch, it will be readily apparent to those skilled in this art that this invention is both simple in design and manufacture as well as versatile in application for incorporation in standard pushbutton switches. The several modifications of additional sliders disclosed herein are interchangeable so that the demands of the customer may be satisfied by incorporating a small change in our standard production switch with little or no increase in cost. While we have chosen as the preferred embodiment a coil spring acting against the end of the additional slider, a similar result would be obtained by using one or more flat column springs 70 which are bowed by compressing their ends within the housing to form an asymetrical curved S-shape when held in the base against the slider, as shown in Fig. 7. Hence, when the additional slider is compressed the S-shape of the spring will provide a biasing force against it, it being under stood that the slider bears against the spring at a point offset from the center of the spring.

Modifications of this invention will occur to those skilled in this art and it is to be understood, therefore, that this invention is not limited to the particular em bodiments disclosed but that it is intended to cover all modifications within the true spirit and scope of the invention.

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

1. In a multiple pushbutton switch comprising a housing, a plurality of elongated longitudinally extending sliders assembled in the housing in side-by-side relation for sliding movement therein, one edge of several of the sliders being undercut to form cam surfaces, a plurality of movable contact blades engageable with the cam surfaces of the sliders, each blade being fixed at one end to the housing and free to move at its opposite end to make and break contact with a fixed contact of the switch, a plurality of manually depressible pushbuttons into said housing through a wall thereof, each of said pushbuttons having an outermost normal position and a depressed actuating position, each slider having inclined surfaces which cooperate with at least one of said pushbuttons, the inclined surfaces being arranged on the different sliders so that only one button may be fully depressed at one time; the improvement comprising a spring bearing against the end of at least one additional slider, and an actuating recess fromed in said one slider and arranged to cooperate with at least one of said pushbuttons, said spring braced against an internal end wall of the housing so that the depression of said one pushbutton will cause the cooperation of said pushbutton with said actuating recess to move said slider against the spring, said recess including on one side thereof an inclined edge extending generally outwardly toward said one of said pushbuttons and toward said end wall of said housing, a curved inner edge continuous from said inclined edge, and a vertical edge continuous from said curved inner edge and disposed on the other side of said recess, said inclined edge cooperating with said one pushbutton upon the depression thereof to move said slider against the force of said spring, said same inclined edge cooperating with said one pushbutton when manual pressure is released therefrom to return said one slider to its original position in response to the force of said spring thereby to return said pushbutton to its outer normal position.

2, in a multiple pushbutton switch comprising a housing, a plurality of elongated longitudinally extending sliders assembled in the housing in side-byside relation for sliding movement therein, one edge of several of the sliders being undercut to form cam surfaces, a plurality of movable contact blades engageable with the cam surfaces of the sliders, each blade being fixed at one end to the housing and free to move at its opposite end to make and break contact with a fixed contact of the switch, a plurality of manually depressible pushbuttons extending into said housing through a wall thereof, each of said pushbuttons having an outermost normal position and a depressed actuating position, each slider having inclined surfaces which cooperate with at least one of said pusnbuttons, the inclined surfaces being arranged on the different sliders so that only one button may be fully depressed at any one time; the improvement comprising a coiled compression spring bearing against the end of at least one additonal elongated slider, said spring biased slider being arrangeable to provide pushbutton returning force or momentary contact actuation in said switch, and an actuating recess formed in said one slider and arranged to cooperate with at least one of said pushbuttons, said spring braced against an internal end wall of the housing so that the depression of said one pushbutton will cause the cooperation of said pushbutton with said actuating recess to move said slider against the spring, said recess including on one side thereof an inclined edge extending generally outwardly toward said one of said pushbuttons and toward said end wall of said housing, a curved inner edge continuous from said inclined edge, and a vertical edge continuous from said curved inner edge and disposed on the other side of said recess, said inclined edge coopcrating with said one pushbutton upon the depression thereof to move said slider against the force of said spring, said same inclined edge cooperating with said one pushbutton when manual pressure is released therefrom to return said one slider to its original position in response to the force of said spring thereby to return said pushbutton to its outer normal position.

3. In a multiple pushbutton switch comprising a housing, a plurality of elongated longitudinally extending sliders assembled in the housing in side-by-side relation for sliding movement therein, one edge of several of the sliders being undercut to form cam surfaces, a plurality of movable contact blades engageable with the cam surfaces of the sliders, each blade being fixed at one end to the housing and free to move at its opposite end to make and break contact with a fixed contact of the switch, a plurality of manually depressible pushbuttons extending into said housing through a Wall thereof, each of said pushbuttons having an outermost normal position and a depressed actuating position, each slider having inclined surfaces which cooperate with at least one of said pushbuttons, the inclined surfaces being arranged on the different sliders so that only one button may be fully depressed at any one time; the improvement comprising a flat column spring positioned transversely adjacent an internal end wall of the housing, said spring being bowed between opposite side Walls of said housing to assume an asymmetrical S-shape, a bowed section of said spring bearing against the end of at least one additional slider, and an actuating recess formed in said one slider and arranged to cooperate with at least one of said pushbuttons, said spring running in compression between the side walls of said housing so that the depression of said one pushbutton will cause the cooperation of said pushbutton with said actuating recess to move said slider against the force of the spring, said recess including on one side thereof an inclined edge extending generally outwardly toward said one of said pushbuttons and toward said end wall of said housing, a curved inner edge continuous from said inclined edge, and a vertical edge continuous from said curved inner edge and disposed on the other side of said recess, said inclined edge cooperating with said one pushbutton upon the depression thereof to move said slider against the force of said spring, said same inclined edge cooperating with said one pushbutton when manual pressure is released therefrom to return said oneslider to its original position in response to the force of said spring thereby to return said pushbutton to its outer normal position.

References Cited in the file of this patent UNITED STATES PATENTS 2,213,845 Mastney Sept. 3, 1940 2,431,904 Andrews Dec. 2, 1947 2,810,027 Woodward Oct. 15, 1957 2,831,075 Dumke Apr. 15, 1958 FOREIGN PATENTS 366,607 Great Britain Feb. 11, 1932 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No, 2,968,704 January 11 1961 Stewart A. Woodward et a1.

It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 4, line 50, after "buttons" insert extending Signed and sealed this 14th day of November 1961.

(SEAL) Attest:

ERNEST W. SWIDER DAVID L. LADD Attesting Officer Commissioner of Patents USCOMM-DC UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 2,968,704 January 17 1961 M Stewart A. Woodward et a1,

It is hereby certified that error appears in the above numbered patent requiring correction and thatthe said Letters Patent should read as corrected below,

Column 4, line 50, after "buttons" insert extending Signed and sealed this 14th day of November 1961.

( SEAL) Attest:

ERNEST W. SW'IDER DAVID L. LADD Attesting Officer Commissioner of Patents USCOMM-DC

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