Function indication means for electric switches
BACKGROUND OF THE INVENTION 
     Rocker switches having non-illuminated visual indicator means are known in the prior art. However these prior switches have been subject to one or more disadvantages such as complexity of design and high cost. This invention relates to improvements thereover. 
     SUMMARY OF THE INVENTION 
     An object of the invention is to provide an improved non-illuminated indicating means for electric switches. 
     Another object of the invention is to provide indicating means of the aforementioned character providing function information in a rocker switch. 
     Another object of the invention is to provide indicating means of the aforementioned character capable of multi-positional window placement for visual exposition of indicia. 
     Another object of the invention is to provide a simple and economical indicating means of the aforementioned type. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an isometric view of a rocker switch constructed in accordance with the invention. 
     FIG. 2 is a top view of the switch shown in FIG. 1. 
     FIG. 3 is a cross-sectional view taken along line 3--3 of FIG. 2. 
     FIG. 4 is a view of an indicia bearing ribbon in disassembled condition. 
     FIG. 5 is a side elevational view, partially cut away, of the switch of FIG. 1, but having a modified window placement. 
     FIG. 6 is an isometric view of a rocker cap showing a window placement therein. 
     FIG. 7 is a view like FIG. 6 but showing another window placement therein. 
     FIG. 8 is a view like FIG. 7 but showing yet another window placement therein. 
     FIG. 9 is an isometric view, partially cut away, of the rocker, indicia bearing ribbon and rocker cap. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to the drawings, the electric switch includes a casing consisting of a box-like insulated switch base 2 and a punched and stamped sheet metal switch frame 4. Switch frame 4 is provided with a cover portion 4a overlying and substantially closing the cavity in base 2. The switch frame also has portions 4b bent downwardly to provide securement of the frame to base 2. Upwardly and outwardly bent portions 4c of the switch frame provide mounting brackets, and generally triangular portions 4d bent upwardly and in parallel with the side walls of base 2 have aligned apertures 4e to accommodate the end portions of a pivot pin 6. 
     The switch contacts and operating mechanism contained within base 2 form no part of the present invention, so disclosure and description of the same is omitted for the sake of clarity. As will be appreciated switch contacts and operating mechanisms that can be used with the present invention can take various forms with one preferred form being like that described in U.S. Pat. No. 2,927,983. It may be assumed that stationary contacts within the base 2 have electrical connection with terminals 8 which extend downwardly from the lower surface of the base. As best shown in FIG. 3, a rocker type operator 10 has an integral depending shank portion 10d which extends downwardly within the cavity of base 2 and carries an elongated recess 10a in which may be assumed to be a spring biased contactor operating lever (not shown) of the type shown in the aforementioned patent. 
     As shown in FIG. 9, a detachable snap-on rocker cap 12 fits over rocker 10 in a shell-like manner and is rigidly mounted thereon, as will be described more fully hereinafter. As seen in FIG. 3, rocker 10 comprises a generally T-shaped integral member having a top portion 10b, a generally semi-circular intermediate stem portion 10c, and an integral depending shank portion 10d. The top portion 10b is formed with a central flat surface, two inclined flat surfaces extending oppositely therefrom at equal obtuse angles, and two curved surfaces extending from said inclined flat surfaces. The semicircular portion 10c is provided with a bushing-like protrusion 10i and a pivot aperture 10f of circular cross-section extending therethrough. Pivot pin 6 extends through the aligned apertures 4e and 10f and through corresponding apertures on the opposite side of the rocker and frame (not shown) to provide pivotal support of the rocker, widened ends of the pin acting as retainers therefor. 
     As shown in FIG. 9, the rocker further has a shallow V-shaped ledge 10g formed on each side of the semi-circular stem portion 10c below the apertures 10f, and a raised shoulder 10h on each side of and running the entire length of the top portion 10b. 
     Rocker cap 12 has an interior contour complementally conformed to the shape of the top portion 10b of the rocker, and an exterior having a central flat surface 12a with a transparent window 12b therein and two opaque inclined flat surfaces 12c and 12d extending oppositely therefrom at equal obtuse angles. As seen in FIGS. 3 and 5, the rocker cap has a downwardly opening slot 12e on each side thereof for engaging in a snap-on manner the bushing-like protrusion 10i around pivot pin 6. The lower edges of the rocker cap are seated by and stopped against the ledges 10g of the rocker and the interior of the rocker cap is seated by and stopped against the shoulders 10h of the rocker to provide a small clearance gap or passageway between the top surfaces of rocker and the top interior surfaces of the rocker cap and to provide unified rocking action of the rocker cap and rocker. 
     A thin acetate ribbon, strip or sheet 16, which in one preferred form is approximately 0.010 inch thick, is slidably received within the passageway. The ribbon may also be formed of nylon, mylar, kapton or any other comparable semi-plastic semi-flexible material or the like. This ribbon extends up from the cover portion 4a of the frame, then into the passageway passing beneath the transparent window in the rocker cap, and then down to the cover portion again, as seen in FIG. 3. As seen in FIGS. 1 and 9, the ribbon must be flexible enough to substantially assume the shape of the interior contour of the rocker cap, yet stiff enough to slide therealong as the rocker is pivoted with the cover portion 4a of the frame acting as a stop therefore. The ribbon must also have a low coefficient of friction to enable it to slide through the passageway. .Iadd.The ribbon is sufficiently rigid to prevent buckling of its lower end sections upon pivoting of the rocker such that part of one of its lower end sections enters the passageway and the bottom edge of the other lower end section remains in substantial abutment with top housing cover 4a and the ribbon effectively slides through the passageway deflectably conforming to the shape thereof to expose a different segment of the ribbon through the window. .Iaddend. 
     As seen in FIG. 4, the ribbon is marked with appropriate indicia for providing function information. As seen in FIGS. 2 and 9, with the rocker cap in its center position, the transparent window will visually expose the indicia &#34;OFF&#34;. Right and left rocking of the rocker cap and rocker will cause visual exposition of &#34;LOW&#34; and &#34;High&#34;, respectively. 
     As seen in FIG. 5, a window may also be placed on inclined flat surface 18c of rocker cap 18. During molding of the rocker cap, the window opening is formed from below in order to assure a flush surface for the ribbon to slide along after the window is placed therein. With the window in the center, as shown in FIG. 3, the opening may be formed from above because the ribbon will bow out slightly from the center interior surface of the rocker cap and hence the bottom of the window need not be perfectly flush with the interior surface of the rocker cap. 
     FIG. 6 shows an alternate embodiment wherein a refractive lense may be used. FIGS. 7 and 8 show alternate rocker caps and window placements therein. 
     It is to be appreciated that the invention encompasses many variations of rocker caps, windows, window placements, ribbons and indicia, all within the scope of the present invention. 
     It is further to be appreciated many types of operators other than rockers and rocker caps may be used, for example, any type of movable operator having a window to expose a ribbon or sheet constrained against moving with the operator will provide the conceived means of indication.