Abstract: A liquid filled gauge for measuring, for example, pressure, includes a gauge housing, a lens cap attached to the housing, a gauge diagnostic element contained at least partially within the housing, a dial that includes a translucent portion and a non-translucent portion and an electroluminescent device positioned adjacent the dial for transmitting light through said translucent portion and illuminating said dial. The dial is operatively connected to the gauge diagnostic element. A protective cover may be provided for sealing the electroluminescent device and protecting the electroluminescent device from the liquid which fills the gauge housing.

Abstract: An injection pressure sensor (10) intended for use with a fluid source (12). The injection pressure sensor (10) has a sensor element (14) in communication with the fluid source (12) and in communication with a pressure reference source (16). The injection pressure sensor (10) also includes a sensor body (20) and a plunger element (26). If the injection pressure sensor (10) experiences high fluid pressures, the sensor element (14) can fail and fluid can escape past the sensor element (14). When the sensor element (14) fails, the plunger element (26) moves from an inactive position (28) into an active position (32). When the plunger element (26) is in the active position (32), fluid is generally prevented from escaping the sensor body (20).

Abstract: A pressure gauge in which the displacement tip of the Bourdon tube is sealed and secured to a bracket of an amplifier movement by a selected solder composition affording a failure response to an encountered overpressure at a pressure value lower than the burst pressure of the Bourdon tube. Overpressure causes a fracture in the solder to be incurred enabling release of the overpressure while a throttle plug situated in the inlet path to the Bourdon tube severely restricts continuing gas flow to the fracture site. As a consequence, released flow from the solder fracture will be at a pressure insufficient to potentially cause explosion of the gauge case/lens to occur.

Abstract: A vent plug assembly for relieving overpressure from within an instrument casing and comprising a body adapted for secured placement within an aperture defined in the exterior wall of the casing and having a thru-bore and a blind recess symetrically spaced apart and of like configuration and internal cross-sectional dimension. A cooperating plug having a top plate and a pair of dependent stubs of like cross-sectional configuration and spacing as the thru-bore and recess of said body is interchangeably insertable within the thru-bore and recess of the body with one of the stubs defining a blind upward recess and the other of said stubs defining a thru-bore.

Abstract: An overpressure relief plug for safeguarding pressure gauges that tend to damage due to internal overpressure comprising a safety plug for interference sealing fit application to an aperture formed in the pressure gauge housing that otherwise communicates the housing chamber that may be subject to overpressure to the ambient atmosphere, which plug is formed from silicon elastomer to define a shank that is pressed into the housing aperture, a grip portion on one end of the plug shank that is to aid in initially applying the plug to the housing as part of the gauge assembly procedure, and a stop cap at the other end of the shank that forms a head for the plug and that is spherically contoured and defines a planar stop annular surface thereabout having a marginal rim proportioned for firm sealing engagement with the exterior surface of the housing on application of the plug to the housing, with the plug shank and aperture being proportioned to "pop out" of the housing aperture when the pressure of the housing ch

Abstract: A multicoil tube type pressure gauge arranged for direct drive of the gauge pointer and for safely handling overpressure in the event of Bourdon tube rupture comprising a casing of round configuration defining a planar upright main chamber, with the casing being indented rearwardly adjacent the axial center of the gauge to define a supplemental chamber, a mounting plate that is common to all the working parts of the gauge secured to the gauge casing over the supplemental chamber and mounting cantilever fashion a tubular spool journaling the gauge pointer shaft, a multicoil Bourdon tube encircling the spool having its sealed end secured to the shaft within the supplemental chamber, and a pressure connection fitting in the form of a connection block anchored to the mounting plate and having a pressure cavity to which the Bourdon tube other end is sealingly secured with its bore in communication with the fitting pressure cavity, with the Bourdon tube direct driving the gauge pointer shaft; the working parts of t

Abstract: A case of sheet metal construction for a pressure gauge having a solid front case wall extending integral from the annular sidewall of the case.

Abstract: A liquid filled pressure gauge in which temperature induced volumetric changes inposed on the liquid fill are compensated for by a tensioned flexible diaphragm secured in a pressure-tight spaced relation on a cover plate for the gauge casing. For receiving the diaphragm pre-tensioned, the cover includes an annulus extending laterally from the cover surface with a negative draft on its circumference. By virtue of the diametral relationship between the outside diameter of the diaphragm about the draft surface of the annulus and the internal diameter of the case opening, the diaphragm incurs a friction fit as the cover is emplaced causing diaphragm tension to be increased.

Abstract: An ultralow pressure relief valve (10) is disclosed. Sealing fluid (24) is held in place by capillary forces inside capillary tube (12). When pressure in tube (11) exceeds capillary forces, sealing fluid (24) is forced into reservoir (14), protecting pressure gage (20) from overpressurization.

Abstract: A combined fluid pressure gage and safety pressure relief device for interconnection with systems wherein excess fluid pressure will cause explosions likely to result in injury to personnel and damage to surrounding equipment. The device accurately measures fluid pressure within the system to which it is connected so long as the system pressure remains within the working range of the pressure gage. However, should the system pressure exceed the normal full scale pressure reading on the gage, the device will instantly and automatically safely vent the system to atmosphere. Once the device is vented the pressure relief mechanism must be manually reset by skilled technicians using special tools before the apparatus can be reused.

Abstract: A vehicular instrument or gauge of the type that has a sealed housing filled with an inert gas and a pressure responsive drive assembly for an indicating element such as a needle pointer. The housing is provided with a pressure relief valve to relieve excessive pressure within the housing that includes an inwardly facing integral frusto-conical projection with a central aperture in the back of the housing that receives a valve member which is actually a rivet covered by a flexible adhesive such as silicone rubber. The amount of adhesive and the housing wall area covered by adhesive determine, with the diameter of the head of the rivet, the pressure at which the rivet will be blown from the housing relieving internal pressure.

Abstract: A sealed differential pressure gauge of the general type shown in Phillips and Zoludow U.S. Pat. No. 3,645,140 in which a sealed housing is provided that includes a flexible diaphragm that is to be exposed to differential pressures to operate a sensitive and accurate motion transmitting indicator device that is in the form of a pivotally mounted helix cooperating with a range spring mounted magnet, with the range spring being linked to the diaphragm so that the movement of the diaphragm, indicates differential pressures and changes thereof, operates the indicator device for reading of the gauge. The housing comprises a housing member and back plate therefor that, together with the rim portion of the diaphragm, are shaped to provide for blowout capability of the gauge that is rearwardly directed out of the back of the gauge should overpressures be experienced when the gauge is in operation.

Abstract: A protective enclosure for an instrument comprising a pair of housings connected to a support ring. An external bracket for securing the enclosure to a mounting structure is attached to the outside of the support ring and an internal bracket for supporting an instrument inside the enclosure is attached to the inside of the support ring. Instrument lines, fluid or electrical, to and from the instrument lead through the support ring.

Abstract: A tire pressure gage for integral mounting on the wheel of an aircraft tire is provided with failsafe features to reduce the likelihood of sudden tire pressure loss through catastrophic failure of the gage. A pressure relief valve vents the case when the threshold pressure is sensed to thereby preclude long-term pressurization of the case should a slow leak develop in the bourdon tube of the gage. A flow-actuated valve in the port leading from the tire to the bourdon tube, seals the tire against pressure loss through the gage when a fast leak is detected such as might occur upon rupture of the tube. The pressure relief valve includes an ejectable plug normally visible externally of the gage case, the presence or absence of the plug providing a positive indication of whether or not the gage case has been pressurized.

Abstract: An improved solid front casing for a pressure gauge that is readily field converted from a dust-tight to either a hermetically sealed air-tight or hermetically sealed liquid-tight construction. A flexible closure element is axially supported over a rear opening in the case by a threaded connection with threads formed in the case peripherally surrounding the opening. For either hermetically sealed air-tight or liquid-tight service a self-threaded closure element is replaced by a flexible diaphragm of controlled spring rate axially clamped by a threaded backup ring. Temperature induced volumetric changes imposed on the liquid fill or air fill are compensated for by the spring rate of the diaphragm. In the event of an overpressure occurring internally of the casing the diaphragm can escape from its clamping relation for affording pressure relief.

Abstract: Excess pressure being supplied to a pressure gauge is controllably relieved through the gauge cavity and an unsealed aperture in a spring-like crystal. A sleeve member extends transversely in a forced engagement between the inside face of the crystal and an annular gasket compressed in surrounding relation about the inlet of the Bourdon tube. The gasket normally seals the passage clearance about the tube inlet against supply pressure leakage therepast but in response to an overpressure is displaced inwardly toward the cavity until leakage can occur. Concomitant displacement of the sleeve member deflects the crystal outwardly a like amount afforded by its spring rate matched in correlation with the maximum anticipated overpressure to be provided for.

Abstract: A gauge assembly is disclosed having a casing formed of two separate cup members joined together in back-to-back relationship so as to form a relatively thick partition wall within the casing. The wall acts to reduce the possibility of parts being projected forward toward an observer in the event the gauge actuating mechanism, which is located behind the partition wall in the casing, should fail.

Abstract: The front edge (2) of a manometer casing (1) is curved inwardly and secures the window shield (3), located in a sealing ring (5), against being pushed out upon superatmospheric pressure in the housing. A partition (17), in which slotted holes (18, 20, 21) are provided for the indicator shaft (19) and for the bolts (16), is arranged between the support (8) for the indicator mechanism (13) and for the bourdon tube (14) and the dial (15), which is held by bolts (16) at a spacing from said support. The slotted holes extend in a direction running from one casing hole (7) to the axis (29) of the housing and are measured to be sufficiently long, so that the support (8) with the dial (15) and the longitudinally displaceable partition (17) located between them is insertable through the rear opening (24) of the casing (1), wherein an extension (10) on the support (8) is to be outwardly displaced through the casing hole (7).

Abstract: A method for assembling a pressure gauge which employs a removable metal safety plate. The gauge movement, comprising a Bourdon tube, pointer, gauge dial and gear mechanism is mounted on both sides of a metal safety plate and the entire assembly is then inserted into the gauge case and fastened in place.

Abstract: A pressure gauge comprising a rigid housing in which a gauge member is located whose interior is subjected to the pressure to be measured. The housing includes a pressure equalizing device in the form of a cup-shaped resilient membrane or a resilient bellows which is subjected to the interior pressure of the housing on the one side and to the ambient pressure on the other side. Furthermore, a closure element which can be blown out is snapped into position in an opening in said housing. The pressure equalizing device is secured to said closure element and is supported by it, thereby simplifying the installation of said pressure equalizing device in the housing.

Abstract: A pressure gauge has a plate on one face of which is mounted a flange portion which extends outwardly substantially at right angles from the plate. The flange has arranged therein an opening for receiving a mounting having an upper face and being adapted to receive a bourdon-like tube, this tube having a portion which extends from said mounting in the form of a hook. Preferably the hook-shaped tube portion has a straight section which forms an angle of about 45.degree. with said upper face, and a curved section which ranges with the straight section and which embraces a pointer mechanism.