Push type electric switch with contact post, movable coil spring contact and interposed non conductive plunger

Claim 2

A push-pull type electric switch assembly for single and matrix applications comprising an elongated, fixed, pin-like contact mounted on a base and a movable contact, means to mount said movable contact perpendicular to said pin, means to bias said movable contact to a closed position against said pin, an insulative plunger having a nose portion at one end, said plunger being slidably mounted on said pin, said plunger being reciprocable between a depressed position wherein said nose portion lies between said pin and said movable contact and a retracted position wherein said nose portion is removed from between said pin and said movable contact, and means to limit movement of said movable contact by said plunger along said pin parallel to the axis of said pin.

Claim 3

The structure claimed in claim 1 wherein said plunger has an axial bore, said pin being receivable within said bore with a sliding fit.

Claim 4

The structure claimed in claim 1 including a plurality of said switch assemblies, said switch assemblies being arranged in a row with their pins in spaced relationship to each other on said base, the movable contacts of each said assemblies comprising a common, elongated, resilient contact threaded along said pins in a zig-zag fashion, whereby said common movable contact is biased against said pins.

Claim 5

The structure claimed in claim 1 including a second movable contact, said movable contacts being mounted one above the other, means to bias said second movable contact to a closed position against said pin, means to limit movement of said second movable contact by said plunger along said pin parallel to the axis of said pin, the nose of said plunger lying between said pin and both of said movable contacts when said plunger is in its depressed position, the nose of said plunger lying between said pin and both of said movable contacts when said plunger is in its retracted position, and means to prevent contact between said movable contacts.

Claim 6

The structure claimed in claim 2 wherein said base comprises a planar member having first and second parallel surfaces, said pin being mounted on said first surface normal thereto, a pair of spaced mounts said movable contact comprising an elongated, resilient contact having its ends affixed to said mounts and being in parallel spaced relationship with said first surface, said mounts being affixed to said first surface on either side of said pin, said mounts being so located with respect to said pin as to cause said biasing of said movable contact.

Claim 7

The structure claimed in claim 2 wherein said plunger has a circular cross-section perpendicular to its axis, and said nose portion has a tapered surface whereby to assist the shifting of said movable contact away from said pin by said plunger as said plunger is moved from said retracted position to said depressed position.

Claim 8

The structure claimed in claim 3 including additional rows of said pins, each of said rows of said pins having its respective common movable contact for said pins thereof, said base comprising a printed circuit board, all of said pins being mounted on said board, one pin from each of said rows making electrical contact with a common portion of said printed circuit on said board.

Claim 9

The structure claimed in claim 5 wherein said movable contact comprises a coil spring.

Claim 10

The structure claimed in claim 5 wherein said base member comprises a printed circuit board, said board having a printed circuit On said second surface, said pin extending through said base and making electrical contact with a portion of said printed circuit.

Claim 11

The structure claimed in claim 5 including a face plate, means for affixing said face plate to said base in parallel spaced relationship to said first surface, said movable contact being located between said first surface and said face plate, said face plate having a perforation therein, the end of said plunger opposite said end having said nose portion extending through said perforation in said face plate with a clearance fit, a flange on said plunger adapted to abut said face plate and determine said retracted position of said plunger.

Claim 12

The structure claimed in claim 6 wherein said plunger has an annular groove into which said movable contact seats when said plunger is in its depressed position.

Claim 13

The structure claimed in claim 10 wherein said means to limit movement of said movable contact along said pin parallel to said pin axis comprises a cylindrical washer surrounding said pin and positioned between said first surface of said base and said movable contact, said washer having an internal diameter sufficient to permit passage of said plunger nose portion therein, said washer having an axial length slightly less than the distance between said first surface of said base and said movable contact, and a cylindrical spacer about said pin and said plunger and positioned between said face plate and said movable contact, said cylindrical spacer having an internal diameter sufficient to permit passage of said plunger and plunger flange therethrough, said cylindrical spacer having an axial length slightly less than the distance between said face plate and said movable contact.

Claim 14

The structure claimed in claim 10 including a color band about said plunger and so positioned thereon as to be visible above said face plate when said plunger is in its retracted position.