Abstract: Methods and apparatuses related to freeze resistant sensing assemblies are provided. An example pressure sensing assembly may include: a first member defining an aperture, the aperture comprising an inner opening disposed on an inner surface of the first member and an outer opening disposed on an outer surface of the first member; a protection diaphragm disposed on the inner surface of the first member; and a sensing diaphragm disposed in a second member fastened to the first member.

Abstract: An overpressure indicator is defined by a housing sized and configured for attachment within a compartment interior, such as an aircraft nacelle. A pressure sensing element disposed within the housing is coupled to an indicator element and is configured to detect a pressure differential between the interior and exterior of the compartment. The indicator element is caused to move in response to a predetermined change in pressure exceeding a threshold pressure differential. The indicator element includes a distal end that is moved to a position exterior of the housing and the compartment, providing a visual indication of an overpressure condition. A reset feature provided on the indicator can only be accessed by first opening the compartment in which the indicator has been mounted. A spring can be provided to assist in the triggering of the indicator member after the threshold pressure differential has been detected.

Abstract: The invention relates to a particle filter device (1) comprising: a fluid inlet (20), a fluid outlet (21), a first fluid flow circuit (31) comprising a first filter zone (2) having a first filter surface (S1), a second fluid flow circuit (32) comprising a second filter zone (3) having a second filter surface (S2) and a constriction (4) having a constant hydraulic resistance so that, in operation, a first portion of the fluid flows through the first flow circuit (31) by passing through the first filter zone (2) and a second portion of the fluid flows through the second flow circuit (32) by passing through the second filter zone (3) and the constriction (4), and the first filter zone (2) reaches a predetermined clogging condition before the second filter zone (3).

Abstract: An advance pneumatic detector to indicate pressure changes in an environment includes a switch, a pressure tube, an endcap, a piston, and a magnet. The pressure tube is connected to the switch. The endcap is disposed on an end of the pressure tube opposite from the switch. The piston is disposed within and forms a seal against the pressure tube. The piston is slidably engaged with the pressure tube. The magnet is slidably attached to and surrounds a portion of the pressure tube. The magnet is configured to control the positioning of the piston within the pressure tube.

Abstract: A contamination indicator is for filter elements (12) for fluids that are replaceably housed in a filter housing (2). The indicator has a fluid-conveying connection (58) to the interior of the housing (2) and possesses an indicating device (52) providing information concerning the degree to which the filter element is contaminated (12). A temperature-dependently active actuation device (50) is connected upstream from the indicating device (52) in the direction of fluid inlet. By the actuation device, the indicating device (52) is activated when the fluid temperature has reached a predefinable threshold value.

Abstract: The invention relates to a pressure indicating device for indicating a pressure in a first fluid system, said pressure indicating device including a first port via which it is fluidically connected to the first system, which pressure indicating device furthermore comprises a cylinder with a preloaded piston that can be displaced therein in an axial direction, during which movement fluid contained in the first system can act on the piston surface. The invention is characterized in that said piston has an opening in its piston surface, which opening can be made to communicate with a second system via a second port, said piston comprising a diaphragm which is impermeable to a first fluid but permeable to a second fluid, said diaphragm separating the first port from the second port.

Abstract: A leak detector assembly for use with a backflow prevention device includes a housing defining a passageway for receiving a fluid. A flap assembly couples to the housing for generating a low flow error signal indicating minimal fluid passing through the passageway and a fully actuated error signal indicating significant fluid passing through the passageway. The flap assembly includes a flap mounted in the passageway such that significant flow of the fluid moves the flap to generate the fully actuated error signal. The flap assembly also includes a sensing element on the flap to determine a presence of the fluid without movement of the flap to generate the low flow error signal based on a low flow of the fluid.

Abstract: A citrus juice apparatus may include at least one citrus juice processing device. The at least one juice processing device may include at least one juice output having a flow of juice therethrough. The at least one juice processing device upon a malfunction may cause an undesired material release along with the flow of juice into the at least one juice output. An undesired material release detector may be coupled to the at least one juice output for detecting the undesired material release. The detector may operate based upon magnetic proximity sensing of a moving filter plate within a housing of the detector. Alternatively, the detector may operate using a filter plate, and based upon pressure.

Abstract: A drive device of an electric power steering apparatus includes a motor housing fixed to a gear housing, a stator, which is received in an inside of the motor housing, a rotor, which is rotatably placed on an inner side of the stator, and a shaft, which is rotated integrally with the rotor. The motor housing includes an engaging portion. The engaging portion has a thread, which is coaxial with a rotational axis of the shaft and is threadably engaged with the gear housing.

Abstract: A pressure differential indicator that eliminates the risk of providing a false positive due to fluid contamination. The invention has an electrically insulated barrier between the “hot” pin and the grounded housing without the need for a hermetic seal. The indicator can be manufactured at a greater efficiency and lower cost than is found with prior art pressure differential indicators. It has a piston that can be easily oriented to yield either a normally closed or normally open position. The indicator has at least one protrusion on a plastic overmold to engage the swage collar and resist axial rotation of the pin. A pressure seal interrupting the plastic overmold sections and exposing the underlying metal to allow for an O-ring seal with no potential leak path between plastic and metal. Finally, the pressure differential indicator has all moving components contained within a single cavity.

Abstract: A pressure-sensing device is for use in an underground well. The pressure-sensing device includes a pressure sensor arranged at least to sense whether a pressure in the well is below or above a given limit value, and a signal generator arranged to generate an acoustic signal in a well body in the well in response to a sensed pressure from the pressure sensor exceeding said limit value. A method is for measuring pressure in an underground well. A use of a pressure-sensing device is to monitor the pressure between two spaced-apart barrier elements in an underground well.

Abstract: The invention relates to a method and apparatus for a gauge for indicating a pressure of a fluid, including a gauge having a face where the face has a first plurality of graduation marks, each for indicating a pressure in an ascending direction. The face also has a second plurality of graduation marks, each for indicating a pressure in a descending direction. In addition, the gauge includes a sensor magnet for detecting the pressure of the fluid, a pointer magnet coupled to a pointer and in communication with the sensor magnet for moving the pointer in correspondence with a movement of the sensor magnet, and wherein the pointer traverses across both the first and second pluralities of graduation marks for indicating the pressure of the fluid in either an ascending direction or descending direction.

Abstract: The invention relates to a method and apparatus for a gauge for indicating a pressure of a fluid, including a gauge having a face where the face has a first plurality of graduation marks, each for indicating a pressure in an ascending direction. The face also has a second plurality of graduation marks, each for indicating a pressure in a descending direction. In addition, the gauge includes a sensor magnet for detecting the pressure of the fluid, a pointer magnet coupled to a pointer and in communication with the sensor magnet for moving the pointer in correspondence with a movement of the sensor magnet, and wherein the pointer traverses across both the first and second pluralities of graduation marks for indicating the pressure of the fluid in either an ascending direction or descending direction.

Abstract: Disclosed is a pneumatic actuator movement indicator comprising a housing adapted to be connected in series between a pneumatic actuator and a source of pressurized fluid for the actuator, and an indicator located in, and having an equilibrium position in, the housing. The housing includes a first chamber for placing the housing in fluid communication with said actuator at a pressure P1, and a second chamber for placing the housing in fluid communication with said source of pressurized fluid at a pressure P2. The indicator is movable in the housing in response to a difference between P1 and P2. Movement of the pneumatic actuator produces a difference between P1 and P2; and in response to this difference, the indicator moves away from its equilibrium position, indicating the movement of the pneumatic actuator.

Abstract: The present invention provides a device, system, and method for detecting and measuring the bi-directional flow of a fluid through a fluid meter, such as a household or business water meter. In one device embodiment the invention comprises a logical switch collar (12) disposed over an analog fluid meter (14) having a sweep-hand (18) with a magnet (16) coupled thereto. In operation, the logical switch collar (12) consists of at least two magnetic switches that are triggered to open or close in response to the rotational movement of the sweep-hand (18) as fluid flows through a fluid meter (14) in both the forward and reverse directions. These switching events are detected and recording by an electronic module (19). Advantageously, the present invention accurately monitors and records fluid consumption at predetermined intervals when the fluid flows through the meter in either direction (14).

Abstract: A magnet is attached to a piston which slides in the interior of a casing due to action of fluid pressure, a guide groove is provided on a side face of the casing in a movement direction of the piston, an indicator is received in the guide groove, and at least one portion of the indicator is formed of a magnetic body, so that the indicator can displace following the piston.

Abstract: A magnet is attached to a piston which slides in the interior of a casing due to action of fluid pressure, a guide groove is provided on a side face of the casing in a movement direction of the piston, an indicator is received in the guide groove, and at least one portion of the indicator is formed of a magnetic body, so that the indicator can displace following the piston.

Abstract: An apparatus and method for a flow-based fire alarm. A bypass system is provided to allow sufficient water flow where a pressure drop, particularly in a residential or multi-purpose piping system such as a water softener is encountered, by providing an alternate, lower pressure flow path allowing additional flow when the pressure drop through the system becomes too great. Flow detection means are also provided with minimal pressure drop to insure that flow for fire protection need is not unduly restricted. The flow detection means includes either a differential pressure switch coupled to an orifice plate or a moving orifice plate having thereon a magnet, which communicates with a Reed switch in proportion to the flow therethrough. An integral system incorporating all of the elements discussed provides multiple levels of security for a fire protection system for use in a residence or other structure.

Abstract: A double differential pressure indicator has a housing containing two pistons arranged in contiguous bores and biased by a single spring extending between opposed ends of the pistons. The differential pressure is applied across both pistons and as the pressure differential increases to a first predetermined difference one piston moves to operate a first indicator which may, for example, be a reed switch. As the differential pressure further increases, the second piston moves to operate a second indicating device which may be a button. In an alternative arrangement, both indicating devices operate at the same differential pressure.

Abstract: A differential pressure switch particularly suitable for monitoring dirt accumulation on a filter element of an oil-separating air filter comprising a piston which is movable in response to a relative change in pressure between two pressure zones and is biased in one direction by a restoring spring, and a rolling membrane which separates the pressure zones.

Abstract: A cover for a pressure sensor for indicating cracks in a hollow aircraft blade, the sensor having a shaft carrying a radiation source, with the shaft sliding in a housing between a first position with the radiation source within the housing and a second position with the radiation source external of the housing, the cover including a sleeve for positioning around the sensor and having an open end for engaging a shoulder of the sensor and having a closed end spaced from the sensor when the open end is engaging the sensor shoulder, and a plunger slidably mounted in the closed end and movable between an outer position and an inner position, with the plunger out of engagement with the sensor shaft when in the outer position and engaging the sensor shaft when in the inner position to move the shaft into the sensor and reset the sensor, with the sleeve being of a material absorbing the radiation of the source.

Abstract: A differential pressure indicator includes a housing having first and second pressure ports for fluid and a bore communicating with the pressure ports. A piston is movable in the bore between an actuated and an unactuated position in response to a pressure differential between the first and second pressure ports. A sensor senses movement of the piston between the actuated and the unactuated positions. A fluid control mechanism varies the effective surface area of the piston communicating with the first pressure port when the piston is in the unactuated position in accordance with variations in temperature of fluid at one of the pressure ports. The indicator is thereby prevented from actuating at low temperatures at which the fluid has a high viscosity.

Abstract: A differential pressure indicator is of the type which uses a magentically attracted spring loaded pop-up button to indicate when the pressure difference between two fluids reaches a predetermined difference. In order to reduce or eliminate false readings caused by fretting between the button and a housing passage in which it slides the button and the passage have a square cross-section to prevent rotation.

Abstract: A filter flow indicator for use with a filter bag into which contaminated aquarium water is pumped which comprises a meter tube connected to a inlet tube by an effective venturi connection. Water flowing in the inlet tube flows across the venturi connection. The rate of flow in the inlet tube is related to the amount of clogging in the filter bag. An indication is included on the meter tube as to when the filter should be replaced. As the filter bag clogs, the flow rate on the inlet tube slows down causing the water level in the meter tube to increase. When the level of the water reaches the indication, the filter is sufficiently clogged so that it should be replaced.

Abstract: An essentially frictionless, reliable pressure indicator capable of withstanding high pressures is disclosed. The invention includes dual opposed springs, a pair of magnetic elements, and a resilient diaphragm abutting one of the magnetic elements. Use of the resilient diaphragm permits precise control of the amount of travel necessary for the magnetic attractive forces to counteract the mechanical spring forces, increasing the accuracy of the overall device. The present structure, with its resilient diaphragm and an associated dampening aperture, is also designed to withstand transient pressures of as much as 2500 psi or more.

Abstract: A fluid filter clogging display comprising a case of non-magnetic material divided into an upper housing, at atmospheric pressure, and a lower housing by an impermeable membrane, a piston movable in the lower housing and dividing the lower housing into a high chamber and a low chamber, the high chamber communicating with an upstream side of a filter and the lower chamber communicating with a downstream side of the filter, a magnet mounted on the piston and disposed in the high chamber, a magnetizable detector in the upper housing for sensing a position of the magnet, a return spring located in said low chamber biasing the piston towards the impermeable membrane and a helical spring made of a shape memory alloy (SMA) which is stiff above a specific temperature and compliant below such a temperature and mounted such that the SMA spring joins the magnet to the piston depending upon the temperature thereof.

Abstract: A fluid flow detection device includes a fluid conduit, at least one magnet translatable by action of the flow of fluid (gas or liquid) in said conduit and a switch which is caused to change state between "on" and "off" relative to the position of the magnet in the conduit. The switch includes several embodiments as does the support for the at least one magnet. In one embodiment the conduit must be positioned in a vertical position in other embodiments the conduit can take any attitude position. A shut off valve can be employed in combination with the flow detection device.

Abstract: A cartridge style, pop up, differential pressure indicator includes a threaded body member, a cover structure and a cylindrical indicator button, which carries a magnet at its lower end, and is slidably supported in the cover for movement between a depressed, hidden position and an extended indicating position. The button is engaged at one side by a leaf spring which in the depressed position urges a lip on the button under a ledge in the cover to serve as a detent. A piston slidably supported in the body is subject to differential fluid pressures and carries a magnet at its upper end, poled in a manner to repel the magnet in the indicator button to urge the latter against the bias of the detent spring and upwardly to the extended, indicating position. A semicircular bimetal strip supported in the cover engages the detent spring at lower temperatures to prevent false release of the indicator button due to cold weather, high fluid viscosity situations.

Abstract: Disclosed is a valve having a body having an inlet channel, an outlet channel in fluid communication with the inlet channel, and a flow-monitoring region situated medially between the inlet and outlet channels. Further provided within the body is a secondary channel having a first end and a second end, the first end in fluid communication with the inlet side of the flow-monitoring region and the second end extending to the outside of the body. The first end of the secondary channel is provided with an area of constriction proximal to the inlet side of the flow-monitoring region. Within the secondary channel is a piston slideably moveably situated. The piston is a pole magnet having a magnetic axis substantially co-linear with the axis of the secondary channel. The diameter of the piston is greater than the diameter of the constriction. Secured within the second end of the secondary channel is a plug. This plug is a pole magnet having a magnetic axis in alignment with the axis of the secondary channel.

Abstract: A flow rate sensor for use with an air filter channels air flow to energize an audible sound generator upon development of an air pressure differential within the sensor above a settable threshold, which pressure differential results from a reduction in the air flow rate through the air filter due to clogging of the air filter by filtered matter.

Abstract: A temperature compensating differential pressure indicating device having a lock-out feature requiring internal reset after actuation. The differential pressure responsive indicating device includes a case having an internal chamber and a piston reciprocably and sealingly disposed in the internal chamber. A piston follower is also reciprocably disposed in the internal chamber and abuts against the piston. A first biasing element biases the piston and the piston follower in a first direction while a second biasing element biases these components in the opposite direction, the second biasing element being weaker than the first biasing element. The piston is displaceable in response to the pressure differential between an inlet pressure and an outlet pressure. A shape memory alloy temperature responsive abutment permits the piston follower to move together with the piston at or above a predetermined temperature, while preventing motion of the piston follower below the predetermined temperature.

Abstract: An excessive pressure differential indicating device for use with a filter in a liquid circulating system. The device has a reciprocable piston that reciprocates between a high pressure location, when the pressure differential is not excessive, and a low pressure location, when the pressure differential is excessive. The device has an indicator button with a magnetically conductive element, and the button is retained in a non-indicating position when the reciprocable piston is at the high pressure location by magnetic attraction between a permanent magnet carried by the reciprocable piston and the magnetically conductive element, a spring being provided to bias the indicator button to an indicating position when the reciprocable piston moves with the permanent magnet away from the indicator button to the low pressure location.

Abstract: An actual pressure of a fluid having an ambient pressure as part thereof is sensed by a sensor. When the actual pressure decreases below a predetermined pressure, a signal is produced. If desired, the sensor may cause production of the signal when the actual pressure of the fluid exceeds a predetermined pressure.

Abstract: A device for indicating differential pressures between first and second pressure sources comprising a housing with a bore and a piston member slidably disposed within the bore and dividing the bore into first and second chambers. The piston member includes a permanent magnet and the housing includes ducts for connecting the first pressure source to the first chamber and the second pressure source to the second chamber whereby the piston member is displaceably responsive to differences in pressure between the first and second pressure sources. The device further comprises indicators in cooperative arrangement with the piston member for indicating at least first and second predetermined differential pressure levels respectively corresponding to respective displacements of the piston member within the bore. The indicators are magnetically coupled to the piston permanent magnet such that they move from non-signalling to signalling positions in response to the respective displacements of the piston member.

Abstract: A water flow failure detection device comprising a first water flow conduit; a second conduit with one end closed and the other end open communicating with the water flow conduit; positioned within the second conduit is a float which is free to translate therein. The float includes a permanent magnet positioned around its longitudinal mid-section; and a reed switch located on the external surface of the second conduit whereby the flow of water through the first conduit sufficiently raises or elevates the float away from the reed switch allowing the reed switch to return to its normal state and an absence of water flow causes the float to translate downward due to gravity to a location adjacent the reed switch thereby changing the state of the reed switch. The reed switch change of state can be used to terminate fuel or ignition to an engine or operates an alarm signal in the absence of cooling water flow through the engine.

Abstract: A differential pressure indicator for use with a filter providing dual indication to indicate both a bypass condition as well as an impending bypass condition. The indicator includes a pressure detector in the form of a piston carrying a pair of permanent magnets. A pair of cylinders each carrying a permanent magnet are concentrically disposed around the permanent magnets carried by the piston. As the differential pressure increases, the piston moves pulling the permanent magnets affixed thereto through the concentrically disposed magnets and as a result of magnetic force interaction the concentrically disposed cylinders move to expose first one and then the other of the cylinders to provide the signals representative of the impending bypass as well as bypass differential pressure being sensed.

Abstract: A magnetic differential pressure valve is provided, having an indicator showing when the valve has moved into one of the open and closed positions, comprising a housing including a valve seat; valve means reciprocably mounted in the housing for movement towards and away from the valve seat between open and closed positions; first magnetic means movable with the valve means toward and away from the valve seat; first bias means urging the valve means and first magnetic means in one direction and normally retaining the valve means and first magnetic means in one of the closed and open positions; second magnetic means movable toward and away from the first magnetic means and normally retained in a first nonindicating position, reacting with the first magnetic means whenever the two means are within their mutually reactive magnetic fields of force, and the valve means is in one of the closed and open positions; and second bias means urging the second magnetic means into one of the nonindicating and indicating posi

Abstract: A differential pressure indicating device which is temperature compensated and includes a piston responsive to a pressure differential between inlet and outlet pressures. The piston is retained in a normal or first position by the force of a spring holding mechanism. The spring holding mechanism releases the piston at a predetermined excessive differential pressure condition to a second position. As this occurs, the piston actuates an indicating member to an indicating condition. A temperature sensitive bimetallic strip is provided to permit the piston to move to the second condition without activating the indicator member when the temperature of the fluid is below a predetermined temperature.

Abstract: An apparatus for detecting and indicating the occurrence of a gas turbine engine stall operates by sensing sudden changes in a selected engine pressure. When a sudden large decrease in the selected engine pressure indicative of a stall is sensed, a visual indication is provided.

Abstract: A magnetic differential pressure indicator is provided for detecting and indicating a pressure differential thereacross that is greater than a predetermined value in a fluid system, having a port that permits introduction or withdrawal of fluid for testing of operability under the predetermined pressure differential, and having a bimetallic element that prevents false actuation of the element at abnormal temperature, and a deactuator for the bimetallic element that permits such testing of the indicator via the port for operability even at such abnormal temperature.

Abstract: A magnetic differential pressure indicator is provided for detecting and indicating a pressure differential thereacross that is greater than a predetermined value in a fluid system. A thermal lockout effective even at high internal fluid pressures prevents false actuation of the magnetic indicating means at low temperatures due to increased viscosity of the system fluid.