Abstract: A downhole pressure transmitter apparatus and method of making the same. A pressure fitting can be provided in association with a tube formed into a spiral shape. One end of said tube is sealed and the other end of said tube is affixed to said pressure fitting. As the tube is exposed to a differential pressure, said tube unwinds, thereby creating a rotary motion that is proportional and linear to said differential pressure sensor, thereby providing an indication of pressure within a downhole environment.

Abstract: The pressure gauge spring is a responsive and easy to manufacture gauge for connection to a pressure source. The spring assembly comprises a coiled hollow tube having a first end and a second end with a body portion therebetween, the hollow tube adapted to produce a displacement of the second end in response to a change in said pressure source to which said first end is connected. The second end of the body portion is sealed. The body portion of the spring assembly has a first longitudinal portion and a second longitudinal portion extending from proximate to said first longitudinal portion to said second end and substantially uniformly compressed along the second longitudinal portion to reduce volume thereby. A transition area is disposed between said first end and said first longitudinal portion of said hollow tube, and is compressed so as to form a continuous longitudinally extending ridge along said transition area.

Abstract: A structure for Bourdon-tube pressure gauge includes a frame on which a needle gear and a limit bar are respectively connected. A Bourdon tube is connected between a test tip and an indicator which is pivotally connected to the frame. A rack portion is connected to the indicator and is engaged with the needle gear no matter how much the indicator swings. A concave portion is defined in a side of the indicator and a protrusion portion extends from the side of the indicator. The indicator is stopped by the limit bar when either the concave portion or the protrusion portion engages with the limit bar.

Abstract: A reduced volume socket body and a reduced volume tube are used in a pressure gauge system in semi-conductor fabrication process equipment. The socket body includes an outlet and the tube has an end connected to the outlet. The outlet is a shaped, weld prep formed on the socket body having an inner surface. A continuous seat is formed on the outlet and includes a seat thickness. The tube has an inner wall and an outer wall defining a wall thickness which is substantially the same as the seat thickness. The end of the tube is engaged with the seat so that the inner wall of the tube and the inner surface of the outlet are substantially aligned to form a crevice free tube-to-socket connection.

Abstract: In general, the invention features a spring assembly for a gauge with a hollow metal tube that changes in volume in response to differential pressures applied across the walls. The tube has a neck connected to a fitting of the gauge, a body connected at one end to the neck with its other end sealed, and at least a portion of the walls of the body being flattened and cold worked to a reduced thickness to thereby increase their yield point to a spring temper. The body is coiled into a spiral or helix. The coiled tube is heat treated to increase its elasticity. The interior of the neck is in pressure communication with the fitting, and the interior of the body is in pressure communication through its unsealed end with the interior of the neck, whereby a change in the pressure applied to the fitting is communicated along the interior of the body changing the differential pressure across the walls of the body to cause a corresponding change in the volume.

Abstract: A pressure gauge is disclosed includes a snap-in interfit between a window and case and between the case and socket. A coiled Bourdon tube within the case directly drives a pointer located intervening between the window and a dial retained by the window.

Abstract: An air pressure gauge is provided integrally with a valve stem extender as used with automotive vehicle wheels mounting tubeless or tube-type air inflated tires. The gauge comprises a Bourdon tube concentrically coiled about the barrel of the valve stem extender and communicated to the interior of the barrel through an orifice provided in the wall of the barrel. The Bourdon tube carries a dial pointer at its outer end which registers with a stationary dial face bearing visible indicia indicating tire inflation pressure. An annular viewing crystal is provided over the pointer and dial face. The gauge displays air inflation pressure reading constantly and need not be disturbed while air is being added to a tire.

Abstract: A dual capacitor device for utilizing dependent capacitances for measurement purposes where an upper capacitor base member and a lower capacitance base member are arranged with parallel capacitor surfaces in horizontal planes and where the parallel capacitor surfaces are located on opposite sides relative to a vertical axis to define first and second capacitors. The lower capacitor base member has a centrally located section connected to an outer section of the lower capacitor base member by a torsion beam and the centrally located section is attached to the upper capacitor base member by a vertical arm member. The torsion beam means has a displacement axis normal to the central axis so that angular displacement of the torsion beam and the centrally located section about the displacement axis produces a capacitance change in the first and second capacitors.

Abstract: A transducer for measuring a moment force as a related function of pressure and tension where a spirally wound bourdon tube has a confined end arrayed to apply a moment force to pretensioned metal vibratory elements. The change in tension in the pretensioned vibratory elements produces a change in frequency which is related to pressure in the bourdon tube. The vibratory elements are maintained at equally applied tension so that a temperature change changes the frequency of the vibrating elements and can be utilized to correct pressure measurements.

Abstract: A differential pressure sensor comprises a pair of bourdon tubes disposed in an arrangement wherein deflections of the two bourdon tubes resulting from fluid pressures connected thereto take place in two opposite directions and the deflective extremities of the two bourdon tubes are linked to one another by a linkage, which linkage is coupled to a transducer that converts the displacement of the linkage to an electrical parameter such as the ohmic resistance, capacitance, reluctance, or resonance frequency as a measure of differential values between two pressures respectively connected to the two bourdon tubes.

Abstract: The present invention is an improvement to a tire mounted air pressure gauge for use on vehicles having inflatable tires. The air pressure gauge has a dial face, with a coiled pressure responsive spring expandable to indicate the pressure detected by the gauge. The gauge is mounted directly onto the valve stem of a tire to detect the pressure in the tire, or is mounted onto the valve steam via an L-shaped conduit. The conduit contains a lug adapted to depress the conventional valve core of the valve stem and release air pressure within the valve stem and tire. An arc-shaped or cylindrical retainer is provided on the dial face to limit radial expansion of the coiled spring due to centrifugal forces of the rotating tire and other jarring forces exerted on the pressure gauge during use of the tire.

Abstract: An improved pressure sensor includes a Bourdon tube, as its sensing element, and an indicator controlled thereby. At least one tightly closed container is secured to a free end of the Bourdon tube and is partly filled with a bulk material. If the Bourdon tube is made to vibrate as a result of pressure shocks or vibration forces acting upon its fixed end frictional forces that consume vibration energy arise between the container and the amounts of bulk material contained. The indicator includes Hall elements and permanent magnets, which magnets are secured on the Bourdon tube and are moved by it relative to the Hall elements.

Abstract: A temperature-compensated Bourdon tube gauge for indicating a parameter of a pressurized fluid, including a support structure, a Bourdon tube having an open fixed end receiving the fluid and a free closed end carrying an indicating member, a dial member carrying a parameter scale disposed along the path of motion of the indicating member, and a temperature-responsive element for moving the dial member in accordance with a sensed temperature such that the indicating member indicates the fluid parameter on the dial member scale. The temperature-responsive element comprises a bimetallic element connected between the support structure and the dial member. The bimetallic element may be connected to the dial member by a lever having a "variable fulcrum" which varies along the length of the lever in accordance with the shape of a cam with which the lever is maintained in contact.

Abstract: In general, the invention features a spring assembly for a gauge comprising a hollow metal tube adapted to change in volume in response to differential pressures applied across its walls, the tube having a neck portion adapted to be connected to a fitting of the gauge, a body portion connected at one end to the neck portion, the walls of the body portions being flattened and their peripheral portions being compressed by cold working to a reduced thickness to thereby increase their yield point to a spring temper and their central portion being compressed relatively less than their peripheral portions to form an axially extending channel which provides for enhanced pressure transmission along the tube, and the other end of the body portion being sealed, the interior of the neck portion adapted to be in pressure communication with the fitting, and the interior of the body portion adapted to be in pressure communication through the channel with the interior of the neck portion, whereby a change in the pressure ap

Abstract: A bourdon tube for gas and liquid-filled thermometers and pressure gauges constructed by edge welding two strips of isoelastic nickel alloy to form a wall to wall low volume bourdon tube that exhibits a low ambient temperature effect and improved rangeability over all existing bourdon tubes used for temperature and pressure measurement and control.

Abstract: A digital pressure transducer is formed by mounting a force-sensitive resonator to a structure of nonsymmetrical configuration which produces loads under applied pressure. The frequency of the resonator is measured to provide a digital indication of the applied pressure.

Abstract: A pressure gauge is disclosed which is generally suitable for use in connection with a fire extinguisher. The pressure responsive element is rotatably secured in position in the casing by an adjustable sleeve. The zero reference dial mark is provided on the casing, while remaining dial indicia may be on the viewing crystal. Both "off-pressure" and "on-pressure" alignment of the pointer and dial markings are enabled prior to sealing of the crystal to the casing. The seal between the crystal and the casing is ultrasonically formed and contains a weakened segment to enable release of excessive pressure within the casing.

Abstract: A pressure responsive spring element for a gauge is made from cold worked metal.