Texas Instruments Corporation

Stanley G Homol

David A Czarn

A normally closed, fluid pressure responsive electric switch (10) has an electrically conductive body (12) formed with an orifice (12a) leading to a pressure chamber (12c) which is separated from a switch chamber by a flexible member (14). An annular support plate (18) and disc seat (20) are sandwiched in the body by crimping distal free end (12g) of body (12) over the flange (26b) of a connector body (26). A pressure/force converter (22) has a plurality of outwardly extending fingers which are interdigitated with a corresponding number of fingers extending inwardly from an aperture in the disc seat. The converter has one end (18b) engaging the membrane and an opposite end having a circular force applying surface (22g) adapted to engage a snap acting disc (24) disposed on the disc seat within a recess formed in the connector body. The disc is centered by a centering lip (22e) formed on the converter fingers. A terminal (28) extends through the connector base (26) and has a terminal rib (28e) which engages the opposite side of the disc forming an electric path from the terminal through the terminal rib to the disc and from the disc to the disc seat in one of two opposite configurations of the disc and from the disc seat to body (12) through deformed portions (12h) of the body wall (12f). In an alternate embodiment a two terminal switch (10') is provided by placing a second terminal (34) in electrical engagement with disc seat (20') and electrically isolating the disc seat from the body (12).

Normally closed, pressure responsive electrical switch

A high pressure switch (10) is shown having a housing member (12) with an orifice (22) extending from a first end (18) to a recess (24) formed in a surface (26) in a central portion (14) of the housing. A sidewall (28) extends from surface (26), leaving a shoulder around the recess, forming a cavity (32). An annular support plate (34) is received on the shoulder of surface (26) capturing a flexible membrane (36) which closes recess (24) to form a pressure chamber. An eyelet (40) is disposed contiguous to the support plate (34) and is locked in place by deforming the outer distal portion (30) of wall (28) radially inwardly over the outer periphery of eyelet (40). A terminal (44) is mounted on eyelet (40) but electrically isolated from the outer ring of eyelet (40) by electrically insulating material (46). A pressure/force converter in the form of a piston (58) is received in the bore of annular support plate (34) and is provided with a circular force transfer rib (64) adapted to transfer force to an electrically conductive, snap acting disc (50) upon the occurrence of a selected level of pressure in orifice (22). Snap acting disc (50) is disposed on a disc seat (48) formed in eyelet (40) and captured there by projections (54) formed above the disc seat (48). Disc (50) normally is out of engagement with a stationary contact (52, 52') when in a non-actuated configuration but is adapted to form an electrical path between the stationary contact (52, 52') and the housing (12) when the disc (50) snaps to its actuated configuration.

High pressure switch apparatus

A pressure responsive switch is shown having an electrically conductive body 12 formed with a bore 24 which extends from one side through the body into recess 30 formed in the opposite side of the body. A switch assembly 34 is received and locked in the recess by crimping downwardly extending wall 32 of the body over the assembly. The switch assembly has a terminal 35 formed with a stationary contact 36 on an end thereof mounted electrically isolated from an annular disc seat member 40 which in turn receives an electrically conductive disc member 56 and a flexible diaphragm 60. An elongated piston 64 is receivable in a port 18 of a pump and is slidably received in bore 24 of body 12 with an end 70 placed contiguous to the diaphragm 60 and center of the disc member 56. A piston retainer ring 68 is disposed on piston 64 adjacent end 70 and located so that a selected preload is placed on the switch assembly which in turn maintains the piston 64 in a vertical orientation relative to a retainer shelf 66 against which the retainer ring reacts.

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Taunton, MA, United States of America

Stanley G Homol