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US 4,304,973 AGranted
Rugged low force switch apparatus
AssigneeOtis Elevator Company
InventorsThomas J. Fenelle, Jip F. Chun
Life of this patent
Estimating the term…
Abstract
A pressure plate is depressed to actuate a momentary closing switch by exerting pressure on a flexible cover on the switch through a semi-rigid separator and an elastomeric diaphragm. A projection on the plate contacts the separator to focus the pressure on a portion thereof. A foam ring is disposed around the projection and between the plate and separator and is compressed as the plate is depressed.
Claims4
A switch apparatus, comprising:
- a low force switch of the type having a resilient cover thereon to which force is applied for actuating said switch;
- a pressure plate which is depressed for applying said actuating force to said cover, said plate including a force concentrating projection having a flat surface through which said force is applied to said cover;
- and
- a generally planar semirigid separator;
- and
- a generally planar elastomeric diaphragm;
- said separator and said diaphragm being disposed between said plate and said cover;
- said actuating force being transmitted from said plate to said cover as said projection is forced against a portion of said separator, said portion thereby forcing a corresponding portion of said diaphragm against said cover;
- said separator being characterized in that said portion is smoothly curved and said actuating force is substantially evenly distributed over said portion;
- and
- said diaphragm being characterized in that said corresponding portion conforms to said separator portion and provides a cushion between said separator portion and said cover.
8 more elements
Dependencies are inferred from the claim text.