HOWARD W NUDD, JR
Engineering in Foxborough, MA

4766769, Aug 30, 1988

Jul 13, 1987

7/072514

Howard W. Nudd - Foxboro MA
David N. Demoura - Taunton MA

The Foxboro Company - Foxboro MA

G01L 708, G01L 900

73706

A differential-pressure instrument the body of which forms a sealed interior pressure chamber containing a fill-liquid and includes a pair of flexible diaphragms to apply to the fill-liquid an input differential pressure to be sensed by an IC strain-gauge chip within the chamber. A spring plate divides the interior pressure chamber into two sections and is deflectable in response to differential pressures. Overrange pressure protection is provided by a valve which is closable by an elastomeric pad carried by the spring plate when the plate deflection reaches a pre-set amount. Valve closure locks the fill-liquid in place alongside the plate to provide an incompressible liquid back-up preventing further deflection of the plate, thus preventing further increases in differential pressure across the IC chip. In one embodiment, valves are placed on both sides of the spring plate to protect against both high-side and low-side overrange pressures. In another embodiment, a washer is secured to the spring plate to provide a relatively high spring-rate for deflection in the high-side direction, so that the instrument can more readily be employed for measuring high-span differential pressures.

4693121, Sep 15, 1987

Jun 5, 1985

6/741538

Howard W. Nudd - Foxboro MA
David N. De Moura - Taunton MA

The Foxboro Company - Foxboro MA

G01L 708, G01L 900

73706

A differential-pressure instrument the body of which forms a sealed interior pressure chamber containing a fill-liquid and includes a pair of flexible diaphragms to apply to the fill-liquid an input differential pressure to be sensed by an IC strain-gauge chip within the chamber. A spring plate divides the interior pressure chamber into two sections and is deflectable in response to differential pressures. Overrange pressure protection is provided by a valve which is closable by an elastomeric pad carried by the spring plate when the plate deflection reaches a pre-set amount. Valve closure locks the fill-liquid in place alongside the plate to provide an incompressible liquid back-up preventing further deflection of the plate, thus preventing further increases in differential pressure across the IC chip. In one embodiment, valves are placed on both sides of the spring plate to protect against both high-side and low-side overrange pressures. In another embodiment, a washer is secured to the spring plate to provide a relatively high spring-rate for deflection in the high-side direction, so that the instrument can more readily be employed for measuring high-span differential pressures.

4149422, Apr 17, 1979

Oct 13, 1976

5/732130

Everett O. Olsen - Wrentham MA
Howard W. Nudd - Foxboro MA

The Foxboro Company - Foxboro MA

G01L 110, G01L 1306

73704

A pressure measuring instrument of the vibrating-wire type comprising an elongate base on which is pivotally mounted an elongate lever parallel to the base. A vibratory wire in the form of a very thin flat ribbon of tungsten is held tautly between the lever and the base. A pair of bellows are supported on the base, on opposite sides of the pivot mounted for the lever, and apply a torque to the lever proportional to differential pressure. Counterbalance means are provided to prevent errors with changes in spatial orientation of the instrument. The lever support-structure is formed of a composite of elements providing a match of temperature expansion characteristics with the vibratory wire. An overrange protection mechanism prevents the application of excessive force to the wire.

5159949, Nov 3, 1992

Jun 10, 1991

7/712507

Robert C. Prescott - N. Marshfield MA
Donald C. Simpson - Norton MA
Philip H. Sanford - Walpole MA
Howard W. Nudd - Foxboro MA

Dresser Industries, Inc. - Dallas TX

G05D 1620

137 84

A transducer having an explosion-proof housing with a divider forming two compartments, and the divider having formed therein a well. A magnet and flapper arm arrangement is suspended within the well. A coil winding is fixed in the other compartment around the well so that a magnetic field generated thereby influences the pivotal position of the magnet. Set screws adjustable in the bottom of the well are effective to preset a rest position of the magnet.

4221133, Sep 9, 1980

Oct 25, 1978

5/954628

Everett O. Olsen - Wrentham MA
Howard W. Nudd - Foxboro MA

The Foxboro Company - Foxboro MA

G01L 110, G01L 1306

73704

A pressure measuring instrument of the vibrating-wire type comprising an elongate base on which is pivotally mounted an elongate lever parallel to the base. A vibratory wire in the form of a very thin flat ribbon of tungsten is held tautly between the lever and the base. A pair of bellows are supported on the base, on opposite sides of the pivot mounting for the lever, and apply a torque to the lever proportional to differential pressure. Counterbalance means are provided to prevent errors with changes in spatial orientation of the instrument. The lever support-structure is formed of a composite of elements providing a match of temperature expansion characteristics with the vibratory wire. An overrange protection mechanism prevents the application of excessive force to the wire.

5257639, Nov 2, 1993

Aug 24, 1992

7/934787

Robert C. Prescott - Marshfield MA
Donald C. Simpson - Norton MA
Philip H. Sanford - Walpole MA
Howard W. Nudd - Foxboro MA

Dresser Industries, Inc. - Dallas TX

G05D 706, F16K 3108

137 82

A transducer having an explosion-proof housing with a divider forming two compartments, and the divider having formed therein a well. A magnet and flapper arm arrangement is suspended within the well. A coil winding is fixed in the other compartment around the well so that a magnetic field generated thereby influences the pivotal position of the magnet. Set screws adjustable in the bottom of the well are effective to preset a rest position of the magnet.