Abstract: A remote pressure or vacuum sensing device including a housing having first and second chambers separated by an internal wall, the first chamber being in fluid communication with a pressurized or vacuum environment to be monitored. An activator assembly is carried within the first chamber for axial movement therein between a terminal position and other positions in response to fluid communication of pressure or vacuum conditions of the monitored environment to a portion of said activator assembly. An activatable assembly is carried within the said second chamber for activation upon movement of the activator assembly from its terminal portion to other positions to provide signals for indicating pressure changes in the monitored environment.

Abstract: The invention comprises a differential pressure switch including a housing which defines a cavity. A diaphragm with a pair of magnets mounted thereon is attached within the housing and vertically disposed across the cavity. This divides the cavity into a high pressure chamber and a low pressure chamber. A high pressure port and ducts in the housing place the medium to be detected in communication with the high pressure chamber. A low pressure port and ducts in the housing place the medium to be detected in communication with the low pressure chamber. The ducts also allow the chambers to drain. A reed switch is attached to the housing proximate the first magnet for maintaining the reed switch in an open state. A third magnet is positioned on the side of the diaphragm opposite the reed switch and in opposition to the second magnet for setting the switch. The third magnet may also be used to adjust the pressure differential required to actuate the reed switch.

Abstract: A sensor or regulator capable of operating at high absolute pressures and for measurement of pressure, especially pressure differential, or liquid level, is disclosed and has a member which moves in response to pressure differential and being coupled directly to a diaphragm via a lever linkage or which is displaceable by a float and which is juxtaposed with an inductive proximity switch responsive to movement of the member where the proximity switch can be mounted directly in a pressure-retentive wall, a sight glass or like pressurizable partition partition need not be provided. In the preferred construction, however, such a glass, sealed in the pressure wall of the housing, is interposed between the inductive proximity switch and the movable member to which that proximity switch responds. A method of controlling oil/refrigerant mixtures in a refrigerating plant is also disclosed.

Abstract: A guide projecting into a bladder is provided on a plug of a vessel body. A cup-shaped sensor is slidably provided on the guide, and an element for actuating a switch is provided on the cup-shaped sensor. The cup-shaped sensor is caused to slide along the guide by the bladder deformable in accordance with change in the pressure of liquid within the accumulator, so as to actuate the switch.

Abstract: The apparatus is of the kind comprising a flow detector supplying, in the absence of flow, a stop down signal for the pump, a pressure detector supplying, for a predetermined minimum value of the pressure, a start up signal for the pump, and impeller means for the pressure detector, and is featured by the fact that the pressure detector comprises a movable part (1, 2) which is integral with a membrane (3) closing a cavity (3b) communicating with the hydraulic network, and a fixed part (4, 5) arranged in the apparatus body at the displacement position of the movable part (1, 2), the impeller means for the movable part of the pressure detector are constituted of a spring (8) mounted between the said movable part (1, 2) and the apparatus body (9), the flow detector comprising a part (6, 7) which is movable in the vertical direction and performs the function of gravity closing valve, and a fixed part (4, 5) which is arranged in the apparatus body.

Abstract: A gas-pressurized collapsible bladder inside a fluid accumulator in a hydraulic system has a detection device that informs a user about the state of inflation of the bladder. Abnormalities in system operation, e.g., a gas leak from the collapsible bladder or sudden turning on of the fluid-actuated device in the system can cause bladder deflation whereas clogging of lines or sudden stoppage of a fluid-actuated device may cause fluid pressure rise in the system, and hence, deflation of the collapsible bladder to actuate the detection device. In one aspect of the invention, the condition of the bladder is detected by use of a permanent magnet that actuates a reed relay. In another aspect of the invention, a light-emitting diode, a reflector and a photosensor detect the bladder condition.

Abstract: A reed switch includes a housing in which extends a stepped bore for slidably receiving a magnet carrying sleeve. The sleeve includes a longitudinal bore which receives a glass tube. The sleeve is slidable with respect to the glass tube. The glass tube encloses a switch element. The longitudinal bore is connected to the environment via pressure-equalizing bores in order to avoid the build-up of a high pressure or a vacuum inside the read switch. Collecting pockets for dirt particles are provided between the sleeve and the housing. The stepped bore opens at one end of the housing. The open end of the housing has an inner chamfer which forms an edge from which fluid easily falls away.

Abstract: In a diaphragm apparatus, such as a switch having a diaphragm to be driven by a pressure difference between two spaces, an iron disk is fixed to the center of the diaphragm and a ring-shaped permanent magnet is fixed to an inside wall of a case to magnetically attract the iron disk. This provides hysteresis in the force-motion characteristic of the diaphragm to reduce hunting.

Abstract: A liquid level system employs a bellows which is in flow communication with a differential pressure unit by a column of reference liquid. A float in the bellows carries a switch which energizes an alarm when liquid in the column is lost.

Abstract: A pneumatically operated device responsive to a signal pressure applied thereto from a source of negative pressure for controlling the atmospheric air applied to a control device and for controlling an electric signal applied to an electric control circuit. The pneumatically operated device includes a diaphragm assembly assembled within a housing to subdivide the interior of the housing into first and second chambers respectively in open communication with the negative pressure source and the atmospheric air, and valve and switch mechanisms arranged within the housing to be operated in response to movement of the diaphragm assembly caused by the pressure difference between the first and second chambers.

Abstract: A water supplying system has a pneumatic tank storing water and confining compressed air therein. The pneumatic tank is adapted to be charged with water by a pump. The supply of compressed air into the pneumatic tank is controlled in such a manner as to maintain a constant amount of compressed air in the pneumatic tank. A pressure-responsive device is attached to a water service pipe through which the water is discharged from the pneumatic tank and delivered to faucets or the like. The pressure-responsive device has a pressure-responsive valve adapted to break the communication between the pneumatic tank and the water service pipe when the water level in the pneumatic tank has come down near the port of the tank connected to the water service pipe, and a pressure switch adapted to control the operation of the motor for driving the pump in relation to the operation of said pressure-responsive valve.

Abstract: A leak detection apparatus (18) is provided in a pressurized assembly (10) to signal a loss of pressure or vacuum downstream from a source of pressure or vacuum. A rod (60,160,260) is carried on a valve (62,162) and a diaphragm (38,138) which seals the source of pressure or vacuum from the system. A loss of pressure or vacuum downstream of the valve (62,162) and diaphragm (38,138) moves the rod (60,160,260) to a signalling position to alert an interested party that the system is lacking pressure or vacuum.

Abstract: A tire puncture detecting device having a pressure chamber defined by a flexible diaphragm and held in communication with the interior of the tire, an atmospheric chamber communicating with the atmosphere, and a spring plate member disposed in the pressure chamber and supporting on the front face thereof a magnet and on the rear face thereof a central portion of the flexible diaphragm. The spring plate member is normally maintained in a retracted position under the air pressure in the pressure chamber against the bias of a resilient member disposed rearwardly of the spring plate member. When a reduction in the air pressure in the pressure chamber exceeds a predetermined degree, the spring plate member buckles so as to quickly project forwardly under the force of the resilient member. In this manner, the magnet supported on the spring plate member is moved closer to an alarm circuit switch located in front of the device and energizable by magnetic force, thereby actuating the switch.

Abstract: A switch device (10, 10') which is responsive to various pressures is disclosed. The device (10, 10') includes a housing (18, 18') and plurality of switches (102, 104, 106, 168, 170, 172). A flexible diaphragm (40, 40') is supported external of the housing (18, 18') and has a first face adapted to face a pressure source and a second face facing an external wall (56, 56') of the housing (18, 18'). A plurality of first magnets (46, 48, 50, 182, 184, 186) are connected to the diaphragm at different locations thereon. A plurality of second magnets (108, 110, 112, 174, 176, 178) are supported in the housing and are each connected to one of the switches for activating a respective switch. Each of the second magnets is disposed adjacent one of the first magnets to form a plurality of pairs of first and second magnets whereby the motion of one of the first magnets of one of said pairs causes the second magnet of said last-mentioned pair to move and activate one of the switches to which it is connected.

Abstract: A differential pressure switch device having a flexible diaphragm between two chambers subject to differential pressure, a permanent magnet movable with the diaphragm against a biasing force when pressure differences occur in the chambers, a thermo ferrite combined with the magnet for cooperation therewith, and a reed switch assembly actuated by the movement of the magnet and through the action of the thermo ferrite which becomes magnetic or non-magnetic depending on the temperature.

Abstract: A pressure switch unit capable of withstanding high pressures without losing its low pressure sensitivity or calibration includes a magnetically actuated switch responsive to the magnetic field of a permanent magnet mounted on a hermetically sealed bellows which contains on its interior a substantially incompressible liquid. The amount of liquid hermetically sealed within the bellows is selected to be sufficient to prevent any portion of the bellows from exceeding its elastic limit when the bellows is compressed by exposure to excessively high pressures.

Abstract: Liquid level sensing means comprising galvano-magneto effect transducing means, magnet means for applying magnetic flux to the transducing means, switching means movable with respect to the transducing means and having an influence on the magnetic flux applied from the magnetic means to the transducing means so that an electric signal is produced by the transducing means when the switching means has passed by the transducing means from one side to the other side thereof, one of the transducing means and the switching means being held stationary, and the other being movable in accordance with a change in liquid level.

Abstract: If the pressure switch pre-loading cam has been set for a level above medium the pressure switch is returned to medium after completion of the wash cycle by momentary energization of the solenoid to unlatch the slider from the lobed cam. The slider carries the high and extra high settings and when it is disconnected from the cam the torsion spring on the cam shaft can drive the cam back to medium by pushing the slider out of the way. This arrangement prevents inadvertent repeated use of the higher water level settings, thus preventing inadvertent use of hot water.

Abstract: The patient breathing monitoring apparatus is used for monitoring the airway of a patient which has a respirator connected thereto and which is connected to a source of gas. The respirator is of a type which during the inhalation phase supplies inspiratory gases to the airway of the patient and during exhalation phase permits the discharge of gases from the airway of the patient. The monitoring apparatus includes first and second pressure switches each of which has an inlet connected to the airway of the patient. One of the pressure switches is adjustable to sense a decrease in pressure in the airway below a predetermined value whereas the other of the switches is adjustable to sense an increase in pressure in the airway above a predetermined value. An alarm devices is coupled to the pressure switches for giving an alarm when the one switch senses a decrease in pressure below the predetermined value and when the other of the switches senses an increase in pressure above a predetermined value.

Abstract: A low tire pressure detector and magnetic signal sending unit includes a bellows charged to a reference pressure for moving a magnet from a shielded position to a signal emitting position when tire pressure operating outside the bellows decreases to a predetermined value. A latching force is established by the magnet to operate against the bellows force to help maintain the magnet in the shielded or non-signalling position. The magnitude of the latching force is controlled by a polepiece of thin cross section which saturates under the influence of the magnet to limit the latching force to a fixed value. The spring force of the bellows is sufficient in the absence of a pressure differential to overcome the latching force and move the magnet to signalling position. A ferrous slug mounted on the movable end of the bellows is magnetically coupled to the magnet assembly to form a releasable connection between the magnet assembly and the bellows.

Abstract: A brake fluid reservoir includes a main body portion having a cap securing a diaphragm between the body and the cap. A sensor is mounted to protrude into the reservoir for indicating a predetermined minimum level of brake fluid in the reservoir. The diaphragm is provided for corresponding movement in response to decreases in the level of brake fluid in the reservoir and also for separating a brake fluid containing portion of the reservoir from an air containing portion. The diaphragm includes an interstice for permitting air in the air containing portion to be drawn into the fluid containing portion under preselected conditions. A protective device surrounds the sensor for maintaining the movement of the diaphragm from interfering engagement with the sensor. The brake fluid reservoir may be used in a vehicle brake system including a master cylinder connected for fluid communication with the reservoir and with the front and rear brakes of the vehicle.

Abstract: A pressure differential switch device having a flexible diaphragm between two chambers subject to differential pressures and a permanent magnet movable with the diaphragm against a biasing force when pressure differences occur in the chambers; the magnet moving to a position in which the magnetic field of the magnet actuates the contacts of a reed switch assembly.

Abstract: To provide positive on-off switching when a pneumatic pressure threshold is passed, a movable switching element is magnetically attracted by a moving magnet, movable under force of a pressure diaphragm subjected to the pneumatic pressure. The movable switch element itself is biassed away from the magnet by a spring which is weaker than the restoring spring counteracting the pneumatic pressure. The non-linear displacement-force characteristics of the magnet cause snap action of the movable switch element, thus providing positive switching at accurately predeterminable pressure positions.

Abstract: A brake fluid reservoir includes a main body portion having a cap securing a diaphragm between the body and the cap. A sensor is mounted to protrude into the reservoir for indicating a predetermined minimum level of brake fluid in the reservoir. The diaphragm is provided for corresponding movement in response to decreases in the level of brake fluid in the reservoir and also for separating a brake fluid containing portion of the reservoir from an air containing portion. The diaphragm includes an interstice for permitting air in the air containing portion to be drawn into the fluid containing portion under preselected conditions. A protective device surrounds the sensor for maintaining the movement of the diaphragm from interfering engagement with the sensor. The brake fluid reservoir may be used in a vehicle brake system including a master cylinder connected for fluid communication with the reservoir and with the front and rear brakes of the vehicle.

Abstract: A shorting element for closing a superconducting current path using contacts of a stabilized superconductor material with the contacts being brought together through the use of a mechanical actuating device, in which the contact surfaces of the contact elements are brought into contact using a pneumatic and/or hydraulic means operated by a pressure medium fed into the interior of at least one spring bellows. The shorting element, which is particularly useful in shorting superconducting magnets, is of a simple design, operationally reliable, and results in small coolant losses from the addition of heat through the shorting element.

Abstract: A differential pressure switch incorporating a differential pressure sensor formed by a body having shaped chambers therein and an elastic diaphram moving a shaft mounting a magnet and coupled magnetically to magnetically operate controllers mounted outside of the body and adjustably positioned relative to the shaft and magnet for a wide range of adjustment.

Abstract: A nonexplosive pressure-responsive switch has a housing containing a chamber which is exposed to a source of pressure and a second chamber containing switch elements. A partition separates the two chambers. The chamber connected to the pressure to be monitored has a longitudinal collapsible bellows mounted inside with a first magnet mounted on its end. In an unpressured condition the magnet will normally touch the partition between the chambers. The second chamber containing the switch elements also contains a second magnet which is mounted in an adjustable cylinder. A third magnet is mounted between the adjustable magnet and the switch contacts. When the first magnet is against the partition, the first magnet pulls the movable magnet in the second chamber against the switch contacts, and when the first magnet moves away from the partition, the adjustable magnet attracts the movable magnet, breaking the switch contacts. A second set of switch contacts can be carried by the adjustable magnet's housing.

Abstract: There is described a pressure-responsive switch device particularly suitable for the detection of a pressure drop in a pneumatic tire on a vehicle wheel, wherein a contact carrying movable rod member is securely urged into a contact closing position by means of a conical compression spring to actuate a warning device whenever the internal pressure of the tire drops below a predetermined level. A permanent magnet may be mounted at the contact point of the switch to impart a quick motion thereto.

Abstract: A flow responsive apparatus having a movable element therein ported and connected to a manifold and tube assembly so that during liquid flow conditions, a liquid head is developed in both the manifold and the tube assembly which lifts the valve element in an upward direction, with the resultant movement being utilized to actuate a switch assembly, thereby indicating the occurrence of liquid flow. When gaseous flow enters the apparatus, the liquid head recedes, causing the tube assembly to move downward; thereby actuating the switch to its alternate position and indicating the occurrence of gaseous flow. The tube assembly is in the down position with either gaseous flow or no flow.

Abstract: A temperature compensated pressure indicator adapted to be mounted within a pressure container includes a reservoir housing and housing member welded together to form a secondary pressure chamber. A bellows member is hermetically mounted within the secondary pressure chamber and communicates with the exterior pressure of the container. Mounted on the bellows member is a movable magnetic member adapted to slide on a hollow guide post as a result of any pressure differentials. A reed switch assembly is held stationary in the guide post by a pair of band springs. The switch assembly is electrically connected to a source of power and an external indicator such as a light. When the bellows member moves the magnetic member close to the switch assembly due to a pressure differential, the magnetic field closes the switch assembly to activate the light. The indicator is substantially non-responsive to wide variations in the ambient temperature.