Abstract: A gauge (10) is disclosed which incorporates an improved case assembly. In one embodiment, a case (14) is designed for use with either a bayonet ring (22) or a friction fit ring such as an elastomeric ring (50) or a push in window (156). In the first embodiment, cam followers (28) are positioned in pockets (46) formed on the case (14) to orient the followers and the followers are then secured to the case, as by welding. Cam surfaces (32) on the bayonet ring (22) cooperate with the followers to secure the ring on the case. When using a friction fit ring (50, 150) the case defines an interior surface (44) to receive the ring. In a second embodiment, curved strips (132) are secured to the exterior surface of the case (130). Cam followers (140) are used on the bayonet ring (138) to cooperate with the cam surfaces on the curved strips to secure the ring to the case. Alternately, an elastomeric ring (50) or push in ring (152) can be used with the case (130).

Abstract: A Bourdon tube and its method of manufacture comprised of a displaceable portion having an arcuate extent of between 170 degrees and 190 degrees, with a controlled size opening contained in the edge face of each end. Secured pressure tight in one end opening is a capillary forming the non-displacement portion of the Bourdon tube, while secured pressure tight in the other end is a seal plug forming the tube tip of the Bourdon tube.

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 improved movement construction for a condition responsive gauge instrument to transmit displacement motion with reduced backlash from a condition responsive element to an output drive. A first embodiment comprises a spring grip between the segment gear of the movement and the pivot actuator imposed by an integral wrap-around tail portion of the segment gear. A second embodiment comprises a second segment gear supported in parallel relation with the first segment gear and operative to impose a weighted relation on the pinion of the output drive. A third embodiment comprises a combination of the first and second embodiments.

Abstract: The stem connection of a back connected gauge instrument placed extending partially through an opening in a panel wall is received in an aperture of an elongated clamp plate adapted to span the instrument parallel to the backside of the panel. A keyed recess in communication with the plate aperture is adapted to interlock with a cooperative surface on the gauge stem at a predetermined location longitudinally spaced behind the gauge. A foot of a leg extending integrally from the plate at one end thereof toward the backside surface of the panel cooperates with a similarly extending preassembled thumb screw extending transversely through the plate at the opposite end to effect mounting. The thumb screw also serves to adjustably draw and secure the gauge into its mounted position.

Abstract: An elongated actuator pin in a pressure gauge extends from a fixed end to a free end to interact with the amplifier for enabling pivotal motion thereof to translate Bourdon displacement to an output pointer. A clamp slideably mounted on the actuator pin is operatively effective when set at a selected location along the pin length to variably offset the free end of the pin from its longitudinal axis for obtaining correct calibration adjustment of the gauge.

Abstract: Method and apparatus for constructing a pressure gauge in which the socket and at least a portion of the movement for driving the pointer are initially formed integral of a molded polymeric plastic composition.

Abstract: The stem connection of a back connected gauge instrument placed extending partially through an opening in a panel wall is received in an aperture of an elongated clamp plate adapted to span the instrument parallel to the backside of the panel. A keyed recess in communication with the plate aperture is adapted to interlock with a cooperative surface on the gauge stem at a predetermined location longitudinally spaced behind the gauge. A foot of a leg extending integrally from the plate at one end thereof toward the backside surface of the panel cooperates with a similarly extending preassembled thumb screw extending transversely through the plate at the opposite end to effect mounting. The thumb screw also serves to adjustably draw and secure the gauge into its mounted position.

Abstract: A pressure gauge in which the amplifier communicating displacement motion of the pressure responsive element to the pointer indicator, is mounted in a spring suspension isolating it from the force transmitting rigid components of the gauge. The spring suspension is effected by a pair of spring members connected to the amplifier including one spring member supporting the amplifier in its isolated relation and another spring member enabling operation of the amplifier to be effected.

Abstract: Amplifier apparatus for providing output motion correlated to condition change motion or deflection of a condition responsive element. The amplifier in a preferred embodiment is mounted onto the condition responsive element for floating conjoint movement therewith. A remotely connected actuator, extending into the motion path, defines a pivot axis for a hinged gear sector arm of the amplifier. In pivoting about the actuator axis, the sector arm operably drives a rotatable output shaft supporting a pointer or the like.

Abstract: A pressure measuring sub-assembly for a pressure gauge is comprised of a Bourdon tube providing total support for the gauge amplifier operably connected to drive an output pointer shaft. Th sub-assembly can be installed as a unit in a gauge housing providing a self-supporting inlet connection for the Bourdon tube.In a preferred embodiment, the amplifier is supported on the displacement portion of the Bourdon tube and in the process of manufacture a swageable clamp is loosely placed near the fixed end of the Bourdon tube to loosely receive the secureable end of an elongated wire actuator. The opposite actuator end extends into the motion path of the amplifier to define a pivot axis therefor. When calibrating the unit for linearity, the Bourdon tube is first pressurized to one-half of rated operating capacity, and while maintaining calibration pressure the clamp is subjected to a bi-directional swaging force which selectively crimps the clamp to secure it to the Bourdon tube and the actuator to the clamp.

Abstract: The casing wall about the aperture through which the Bourdon tube socket connection is received in a pressure gauge cooperates with at least two contiguous surface areas spaced apart on the socket to form a bidirectional casing-to-socket interlock thereat. By means of fasteners securing the casing to the socket, the bidirectional interlock is maintained as to afford the casing increased resistance against a percussive blow of potentially bending magnitude received in either direction.

Abstract: The floating amplifier of a pressure gauge is mounted onto the free end of the Bourdon tube at various effective spacings therefrom correlated to offset any residual tip travel of the individual Bourdon tube.

Abstract: The transparent crystal of a liquid filled pressure gauge casing is physically characterized by a controlled stiffness correlated to the volumetric temperature expansion coefficient of the fill liquid. By virtue of temperature induced expansion of the fluid being accommodated through crystal displacement, affected changes in fluid pressure are substantially minimized in maintaining accuracy of the gauge instrument.