Low profile keyswitch
AssigneeCompaq Computer Corporation
InventorKevin F. Clancy
Life of this patent
Estimating the term…
Abstract
A low profile keyswitch having bearing surfaces on both the inside and outside of the plunger of the keycap member is disclosed. The key switch includes a one-piece switch chimney having a cylindrical upright member, a plurality of arcuate ribs positioned coaxially inwardly of the cylindrical member along with a membrane support member. The chimney receives the cylindrical plunger between the cylindrical member and the ribs to provide bearing surfaces on the plunger closest to the keycap member actuation point to minimize friction when the keycap member is depressed offcenter thereby reducing binding of the keyswitch. A plurality of equidistance upstops are disposed on the lower-end of the plunger to reduce wobble of the keycap member in the extended position.
Claims23
A keyswitch, comprising
- a switch chimney including a first upright member, a second upright member and a membrane support member;
- said first upright member having an inner bearing surface;
- said second upright member having an outer bearing surface, said first upright member being disposed radially outwardly and fixed relative to said second upright member;
- said membrane support member disposed radially inwardly of said second upright member;
- a plunger having a top end and a bottom end movable between an extended position and a depressed position and having an inner bearing surface and outer bearing surface, said plunger inner bearing surface slidably engaging said second upright outer bearing surface and said plunger outer bearing surface slidably engaging said first upright inner bearing surface;
- and
- a membrane received on said membrane support member having at least one opening, wherein said plunger bottom end extends through said membrane opening when said plunger is in said depressed position.
A keyswitch, comprising
- a switch chimney including a first upright member and a second arcuate upright member,
- said first cylindrical upright member having an inner bearing surface,
- said second arcuate upright member coaxially disposed with said first upright member and having an outer bearing surface,
- a keycap member having a plunger and an actuator wherein:
- said plunger movable between an extended position and a depressed position having an inner bearing surface and an outer bearing surface, said plunger inner bearing surface slidably engaging said second upright outer bearing surface and said plunger outer bearing surface slidably engaging said first upright inner bearing surface, and
- said actuator disposed radially inwardly from said first upright member and said second upright member, and
- an urging means having an upper portion fixed relative to said actuator to urge said keycap member to said extended position.
A keyswitch, comprising
- a one piece switch chimney including:
- a first upright member having an inner bearing surface,
- a second upright member spaced radially inwardly from said first upright member having an outer bearing surface, and
- a membrane support member inwardly disposed from said second upright member, and
- a plunger movable between an extended position and a depressed position having an inner bearing surface and an outer bearing surface, said plunger inner bearing surface slidably engaging said second upright outer bearing surface and said plunger outer bearing surface slidably engaging said first upright inner bearing surface.
A keyswitch, comprising
- a keyswitch chimney including:
- a first upright member having an inner bearing surface;
- a second upright member having an outer bearing surface;
- a plunger movable between an extended position and a depressed position having an inner bearing surface and outer bearing surface, said plunger inner bearing surface slidably engaging said second upright outer bearing surface and said plunger outer bearing surface slidably engaging said first upright inner bearing surface;
- one of said upright members including at least four spaced apart arcuate ribs, each of said ribs having at least one shoulder;
- and
- a plurality of blocking members disposed on said plunger to engage said plurality of arcuate rib shoulders on one of said upright members to reduce wobble of the keyswitch in the extended position.
Dependencies are inferred from the claim text.