Samuel Martin Johnston

US Patent:

40401189, Aug 2, 1977

Filed:

Jun 18, 1975

Appl. No.:

5/587807

Inventors:

Samuel Andrew Johnston - Fontana WI

Assignee:

Bunker Ramo Corporation - Oak Brook IL

International Classification:

H01G 700

US Classification:

361283

Abstract:

The following specification is directed to a pressure responsive transducer utilizing dual diaphragms on opposite sides of a sandwich of substrates formed of ceramic and having an intermediate substrate in which a slot is formed to communicate with the diaphragm chamber and eliminate the need for puncturing and/or sealing of one of the diaphragms. External electrical connections to fixed capacitor plates deposited on the outer substrates of the sandwich are extended by forming a lead on the intermediate substrate which connects to the fixed plates through aligned openings in the substrates, that also communicate the chambers formed by the diaphragms.

US Patent:

41601394, Jul 3, 1979

Filed:

Aug 29, 1977

Appl. No.:

5/828622

Inventors:

Samuel A. Johnston - Fontana WI

Assignee:

Bunker Ramo Corporation - Oak Brook IL

International Classification:

N01H 3538

US Classification:

200 83N

Abstract:

A pressure sensitive switch for indicating when a fluid pressure reaches a predetermined limit includes a housing having a top wall and a dielectric substrate within the housing spaced from the top wall. A metal diaphragm is hermetically bonded to the substrate to form a cavity between the top wall and the diaphragm. The diaphragm includes a major resilient portion which deforms responsive to varying fluid pressures within the cavity. A first contact is fixedly mounted relative to the substrate and a second contact, arranged for movement with the deformable diaphragm, is spaced from the first contact in juxtaposition thereto. When the fluid pressure within the cavity reaches a predetermined limit, the second contact engages the first contact to close the switch. When the fluid pressure is below the predetermined limit, the second contact moves with the diaphragm away from the first contact to open the switch. Also disclosed is a barometric version wherein the inside of the diaphragm is partially evacuated and atmospheric pressure outside the cavity works against the diaphragm to open and close the switch.

US Patent:

41765575, Dec 4, 1979

Filed:

Apr 24, 1978

Appl. No.:

5/899236

Inventors:

Samuel A. Johnston - Fontana WI

Assignee:

Bunker Ramo Corporation - Oak Brook IL

International Classification:

G01L 710

US Classification:

73708

Abstract:

A pressure sensor includes a pressure transducer which has an electrical element therein in the form of a pressure-affected capacitance which is electrically connected to an electronic circuit which is operable to provide an electrical signal representing fluid pressure applied to the transducer. The transducer and the electronic circuit are packaged in a housing and are isolated from each other within the housing by a seal constructed of a material having a very low temperature coefficient of dielectric constant. The housing includes a metal can having a closed end with an aperture therein for connection to a fluid system to be monitored. The electrical leads extending between the pressure sensitive variable capacitance and the electronic circuit extend through the dielectric seal spaced from each other and spaced from the metal can so as to be shielded and prevent stray capacitance from the affecting operation. In one embodiment the metal can is provided with a metal stem having a fluid passageway therein in communication with the aperture and the stem is adapted for mounting to a support. In another embodiment, the metal can is covered with an insulating jacket to provide thermal insulation and minimize heat transfer between the sensor and the environment thereof.

US Patent:

42020816, May 13, 1980

Filed:

Mar 16, 1978

Appl. No.:

5/887049

Inventors:

Samuel A. Johnston - Fontana WI

Assignee:

Borg Instruments, Inc. - Delavan WI

International Classification:

H01G 518

US Classification:

29 2541

Abstract:

A method of assembling a pressure sensor is disclosed. The sensor includes an aneroid capsule and an electrical circuit secured to opposite sides of a first insulator. The capsule and circuit are electrically interconnected. Second and third insulators are assembled on opposite sides of the first insulator bearing against respective ones of the aneroid capsule and the electronic sensing circuit. The subassembly so formed then is partially inserted into the open end of a hollow can having a closed opposite end with a port therein. A vacuum is applied to the port to suck the subassembly into the hollow can.