PRESSURE SENSING SWITCH WITH MOVABLE CONTACT DIAPHRAGM

• US 3,845,260 A
• Filed: 05/09/1973
• Issued: 10/29/1974
• Est. Priority Date: 08/07/1972
• Status: Expired due to Term

• Current Assignee: Thomas E. Lohr
• Original Assignee: Thomas E. Lohr
• Inventors: Lohr, Thomas E.
• Primary Examiner(s): Schaefer, Robert K.
• Assistant Examiner(s): Tolin, Gerald P.
• Application Number:
  US05/358,761
• Time in Patent Office: 538 Days
• Field of Search: 200/159B,83N,83A,83R,168G,144B
• US Class Current: 200/83.00N
• CPC Class Codes: B60R 21/268 using instantaneous release of stored pressurised gas B60R21/26005 takes precedence
• CPC Class Codes: G01L 19/12 Alarms or signals
• CPC Class Codes: G01L 9/0044 Constructional details of non-semiconductive diaphragms
• CPC Class Codes: H01H 35/346 in which the movable contact is formed or directly supported by the diaphragm

Abstract

A pressure sensing means responsive to gas pressure within a gas containing vessel of a motor vehicle'"'"''"'"'s inflatable bag restraint system is connected in parallel with a signal means located within the passenger compartment of the vehicle. The connection is such that the signal means receives and becomes energized with power from an electrical power source when the sensing means shifts from a conductive to a non-conductive mode. Normal gas pressures within the vessel maintain the pressure sensing means in the conductive mode. If gas pressure in the vessel falls below a preselected pressure, the pressure sensing means shifts to its non-conductive mode, whereby the signal means becomes energized and serves to inform passengers of the vehicle that the gas pressure is dangerously low.

Claims

1. Pressure sensing means comprising:

a. a single substantially rigid, electrically conductive supporting member having inner and outer faces;

b. a pressure responsive, electrically conductive diaphragm having a portion in sealing engagement with said supporting member and the remaining portion spaced from the inner face thereof, said diaphragm and said inner face defining a hollow compartment having an evacuated state;

c. an integral contact member of substantially constant diameter extending through said supporting member and partially into said hollow compartment, said contact member having a face engaging the inner face of said diaphragm upon application of pressure to the outer face of said diaphragm; and

d. insulating and sealing means disposed between said contact member and said supporting member for insulating said contact member from said supporting member and effecting an air tight seal therebetween so as to maintain said hollow compartment in said evacuated state.

2. Pressure sensing means as recited in claim 1 wherein said supporting member includes a flanged portion having a substantially annular configuration and a boss having a centrally located bore extending longitudinally thereof.

3. Pressure sensing means as recited in claim 1 wherein said diaphragm includes a plurality of projecting portions joined to a connecting bow for spacing said diaphragm from the front face of said supporting member.

4. Pressure sensing means as recited in claim 1 wherein the volume of said hollow compartment ranges from about 1/4 to 3 cubic inches and said contact member extends into the compartment from about 20 to 80 percent of the length thereof.