Delayed-opening switches for vehicles interior lighting

Claim 1

Switch interposed in the electric supply circuit containing a source of current of an interior lighting device of a vehicle and controlled by the movement of a movable panel in a frame of said vehicle wherein said movable panel and said frame constitute two elements of which one element carries said switch, said switch comprising a case provided wiTh a first bottom and a second bottom, and having slidably mounted therein, at right angles to said bottoms, a control rod of which one end projects from said first bottom in such a manner that it is depressed by the other element at the end of the closing movement of said movable panel, said switch being characterized in that it further comprises a metal washer sliding freely on said rod between said first bottom and a shoulder formed on said rod within said case, a metal disk rigid with said rod, electrically insulated from said washer, disposed between said second bottom and said shoulder and registering with a first contact connected to a first terminal of a source of current and with a second contact, thereby said disk engages said first and second contacts when said rod is depressed during the panel closing movement, a first compression spring stressed between said second bottom and said shoulder, a pair of bimetallic strips carried by said first bottom on either side of said rod and having their ends shaped to provide projections directed towards said rod and formed with inlet and outlet ramps for said washer, in order to retain said washer when said bimetallic strips are at room temperature, a second compression spring, weaker than said first compression spring, disposed between said first bottom and said washer, and urging said washer away from said projections of said bimetallic strips, a resistance heating wire coiled about said bimetallic strips and connected through one end to said second contact which engages with said metal disk rigid with said rod and said heating wire connected through its other end to one of said bimetallic strips which is connected to the interior lighting device, said bimetallic strip which is not connected to said lighting device being electrically insulated from said heating wire and being connected to the second terminal of said source of current, said lighting device being connected between said first terminal and the bimetallic strip connected to said heating wire, said washer and said disk being electrically insulated from said first and second terminals when they are spaced from said contacts and bimetallic strips, respectively.