US 3610860 A
Description (OCR text may contain errors)
United States Patent  ELECTRICAL SWITCHES INCORPORATING POSITION-INDICATING MEANS 1 Claim, 1 Drawing Fig.
[52} US. Cl 200/167 A  lnt.Cl l-l0lh 9/18  Field of Search... 200/167 A  References Cited UNlTED STATES PATENTS 3,174,023 3/1965 Doggart 200/ 167 A 3,247,352 4/1966 Reiner.... 200/167 A 2,400,849 5/1946 Steams 200/67 7) 3,053,337 9/1962 Prohaska et al. 200/167 A X Primary Examiner-H. 0. Jones Attorney-Holman & Stern ABSTRACT: An electrical switch incorporating position-indicating means includes a casing having a base. The base carries fixed contacts, and slidable within the casing is a movable contact carrier carrying a movable contact engageable with the fixed contacts. The contact carrier and the movable contact are movable by an operating member which in turn is movable manually to operate the switch. In order to indicate the operating position of the switch, there is provided a light source carried by the base of the switch, and a lens positioned in the operating member of the switch. in one operating position of the switch the contact carrier prevents light from the light source shining through the lens, and so the lens is not illuminated. However, in a second operating position of the switch the contact carrier is displaced from the light source, and so light from the light source shines through the lens, thereby illuminating the lens and giving an indication of the operative position of the switch.
ELECTRICAL SWITCHES INCORPORATING POSITION- lNDlCATING MEANS This invention relates to electrical switches.
A switch according to the invention includes a casing having a base, fixed contacts on the inner surface of the base, a contact carrier mounted for sliding movement in a direction generally parallel to the base, operating means for moving the contact carrier relative to the base between first and second positions, a movable contact carried by said carrier and cooperable with said fixed contacts, a light source carried by said base, and a lens in a surface of the switch remote from the base, said light source directing light within the casing to illuminate said lens, and the arrangement being such that in said second position the contact carrier masks said light source from said lens so that said lens is not illuminated while in said first position. Said contact carrier exposes said light source to said lens so that said lens is illuminated, thereby giving an indication that the switch is in said first position.
The accompanying drawing is a sectional view of an electrical switch according to one example of the invention.
Referring to the drawing the switch includes an open boxlike housing 11 which is moulded in transparent synthetic resin material, and which includes an outwardly directed peripheral flange 12 at its open end. The housing 11 is adapted to be engaged as a snap fit in a hole in the facia panel 13 of a road vehicle.
Adjacent one end of the base 14 of the housing 11, the base 14 includes an integral socket 15 which receives a bulb holder 16 carrying a bulb 17. The bulb holder 16 is wired into the lighting circuit of the road vehicle so that the bulb 17 is illuminated whenever the side lights of the vehicle are switched on. The base 14 carries the fixed switch contacts 18 of the switch, and each of the contacts 18 includes an external terminal member 19 through which the contacts are connected into the circuitry of the vehicle. Slidable within the housing 11, in a plane parallel to the base 14, is a molded synthetic resin contact block 21, which carries a pair of movable contacts 22 cooperable with the contacts 18. The contacts 22 are urged into engagement with the contacts 18 by respective springs 23 acting between the block 21 and the contacts 22, and the block 21 is held against movement away from the base 14 by pegs 24 integral with the housing 1 l.
Pivotally mounted in the open end of the housing 11, and closing the open end of the housing 11, is a rocker-type operating member 25. The operating member 25 is molded in opaque synthetic resin and includes an integral finger 26 which extends towards the base 14. The finger 26 is operatively connected to the block 21 through an overcenter mechanism 27, in such a manner that rocking movements of the operating member 25 relative to the housing 11 between first and second positions causes sliding movement of the block 21 relative to the base 14, between first and second positions. At its end above the socket 15 the operating member 25 is provided with an aperture, which is closed by a molded lens 28, the lens 28 being engaged as a snap fit with the member 25.
The dimensions of the block 21 and the base 14 are such that when the block 21 is in said first position, as shown in the drawings, then the socket 15 is exposed, and light from the bulb l7 shines from the socket 15, upwardly through the housing 11, and through the lens 28. However, when the block 2| is moved to its second position, the socket 15 is covered by the block' 21 so that no light shines through the lens 28. In use, the first position of the block 21 corresponds to an on position of the switch, and an indication that the switch is in its on position is given to the driver of the vehicle by the illumination of the lens 28.
The inner diameter of the socket 15 tapers from a minimum adjacent the base 14, to a maximum part way along the length of the socket l5, and so a frustoconical surface 29 is defined around the bulb 17. As stated above, the housing 11 and the socket 15 are molded in transparent synthetic resin material,
and so light from the bulb l77passes through the surface 29. The positioning of the bulb 1 is carefully controlled so that after passing through the surface 29, light from the bulb 17, is internally reflected within the base 14 and the walls of the housing 11 to illuminate the flange 12 of the housing 11. Thus, when the bulb 17 is illuminated, the flange 12 of the housing 11 constitutes an illuminated bezel surrounding the operating member 25 of the switch, thereby rendering the location of the switch visible at night, and it will be appreciated that the flange 12 is illuminated irrespective of the position of the block 21.
In a modification the bulb holder 16 and the bulb 17 are replaced by one end of an optical cable and an associated lens, the other end of the optical cable being positioned adjacent one of the side lights of the vehicle so that the side light bulb is used to illuminate the flange 12 and the lens 28 through the optical cable.
Having thus described my invention what i claim as new and desire to secure my Letters Patent is:
1. An electrical switch including a casing formed from transparent material, said casing having a base, fixed contacts on the inner surface of said base, a contact carrier mounted for sliding movement in a direction generally parallel to said base, operating means for moving said contact carrier relative to said base between first and second positions, a moveable contact carried by said carrier and cooperable with said fixed contacts, a light source carried by an elongated portion of the base of said case, and a lens in a surface of the switch remote from said base, said light source directing light within the easing to illuminate said lens, and the arrangement being such that in said second position, the contact carrier masks said light source from said lens so that said lens is not illuminated while, in said first position, said contact carrier exposes said light source to said lens so that said lens is illuminated thereby giving an indication that the switch is in said first position, and wherein said elongated socket portion of the base of said casing has an inner diameter which is tapered from a minimum adjacent said base to a maximum part way along the length of said socket thereby defining a frustoconical surface, said light source position within said socket portion such that said frustoconical surface is in surrounding relationship thereto,
l light from said light source passing through said frustoconical surface and internally reflected within the walls of said casing to illuminate the periphery of said casing thereby rendering the location of the switch visible.