Pneumatic snap action switch
First Claim
1. A pneumatic switch, comprisinga switch body formed of metallized ceramic and having a side wall, an open end, a closed end, and an open interior;
- an electrical contact terminal sealingly passing through said closed end and extending from an exterior of said switch body into said interior;
a metal diaphragm arranged over said open end of said body in sealing contact with said side wall and including an electrical contact portion;
metal spring means arranged in said interior between one end of said electrical contract terminal and an inside surface of said diaphragm for performing a snap-action operation upon application of a predetermined force; and
tubular means sealingly formed in said switch body for providing fluid communication between said exterior and said interior in a first state and for sealing off said interior from said exterior in a second state,whereby upon a pressure difference existing between said interior and said exterior of said switch body when said tubular means is in said second state, said diaphragm is deformed and exerts said predetermined force to cause said spring means to perform said snap-action operation and contact both said diaphragm and said electrical contact terminal, thereby making electrical continuity between said electrical contact portion of said diaphragm and said electrical contact terminal.
1 Assignment
0 Petitions
Accused Products
Abstract
A miniaturized pneumatic snap action switch includes a glass or metallized ceramic body that has a convoluted metal diaphragm closing the open end with a glass to metal seal. The interior of the switch is provided at a desired pressure by a sealable tubulation port and the switch actuation members include a C-spring and a Belleville spring or washer sealed inside the switch housing. The switchable electrical path is from the metal diaphragm, through the C-spring and Belleville spring, to a centrally arranged conductive termination pin embedded in the closed end of the body. The combination of the C-spring and Belleville spring provide the snap action, and the C-spring has two hemispherical engagement portions that centralize the forces through the center line of the switch. The switch is intended for miniature applications and the switch body is less than 0.75 inches in diameter.
26 Citations
16 Claims
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1. A pneumatic switch, comprising
a switch body formed of metallized ceramic and having a side wall, an open end, a closed end, and an open interior; -
an electrical contact terminal sealingly passing through said closed end and extending from an exterior of said switch body into said interior; a metal diaphragm arranged over said open end of said body in sealing contact with said side wall and including an electrical contact portion; metal spring means arranged in said interior between one end of said electrical contract terminal and an inside surface of said diaphragm for performing a snap-action operation upon application of a predetermined force; and tubular means sealingly formed in said switch body for providing fluid communication between said exterior and said interior in a first state and for sealing off said interior from said exterior in a second state, whereby upon a pressure difference existing between said interior and said exterior of said switch body when said tubular means is in said second state, said diaphragm is deformed and exerts said predetermined force to cause said spring means to perform said snap-action operation and contact both said diaphragm and said electrical contact terminal, thereby making electrical continuity between said electrical contact portion of said diaphragm and said electrical contact terminal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A pneumatic snap action switch comprising:
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a non-metallic housing being hollow and having a closed-end; a metallic diaphragm arranged over an open end of said housing so as to be hermetically sealed with said non-metallic housing and having an electrical terminal portion; an elongate electrical terminal extending from an exterior of said housing through said closed end into an interior of said hollow, closed-end housing and being in sealing contact with said closed end; metal spring means located in said interior and arranged between an inner surface of said diaphragm and an end of said elongate electrical terminal in said interior of said housing for performing a snap-action operation upon application of a predetermined force; and mean for placing said interior in fluid communication with said exterior in an open state and for preventing fluid communication between said interior and said exterior in a sealed state, whereby when said interior is placed at a different pressure than a pressure at an exterior surface of said diaphragm, said diaphragm deflects and exerts said predetermined force to cause said metal spring means to perform said snap action operation and alters an electrical continuity from said electrical terminal portion through said metal spring means to said elongate electrical terminal. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16)
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Specification