Abstract: A pneumatic sensor switch for giving a warning signal if a pneumatic vehicle tire has too low pressure has a gas-filled chamber, separated from the inflation space in the tire by a flexible diaphragm cooperating electrically with a metal part in the chamber to form an electric switch open at safe pressures in the tire and closed at dangerous lower pressures. There is an electric circuit with battery and transmitter to transmit warning signals to the outside if the switch is closed. There may be a second chamber with an electric switch contact, filled with gas at a lower pressure and also separated from the inflation space in the tire by a flexible diaphragm so that the contact is open at atmospheric pressure therein and closed by the diaphragm at higher pressures. The electric switches of both chambers are connected in series so that a warning signal is given only at pressures in the dangerous range, when both switches are closed, and not at atmospheric pressure nor at safe operating pressures in the tire.

Abstract: Featured for use with a hybrid air bag inflator containing inert stored gas under high pressure is a liquid fueled construction which combines the functions of an initiator, gas generator, and differential low pressure switch into a single device. Instead of being filled with a mixture of combustible gases, the device is filled with a combination of gases and liquids. Alternatively, it makes use of a hybrid squib in conjunction with different combinations of gases and liquids. A pyrotechnic material is used to ignite the mixture regardless of the combination of fuel and oxidant used in the device. A ceramic body is used to house the device. Upon combustion of the mixture, the ceramic body ruptures violently, permitting efficient transfer of the explosive energy to the inert stored gas in the hybrid inflator.

Abstract: A single device acts as a pressure switch, gas generated heater, and an igniter. The device has pyrotechnic material such as a combustible gas in an inner chamber. An outer chamber, that is, a chamber in which the device is positioned, includes a gas that may or may not be combustible. A monitor current flows through a pressure monitor resistor and a bridgewire resistor monitoring continuity. When the pressure in the outer chamber decreases below a threshold value, the pressure monitor resistor breaks continuity and causes a resistance change. If an air bag is to deploy, the bridgewire resistor heats up to a point that the pyrotechnic material in the inner chamber is ignited. The resulting combustion ruptures pressure discs and the outward hot product heats the gas in the outer chamber. The outer chamber ruptures and the heated gas therein flows in the air bag.

Abstract: A differential pressure switch has a main switch body divided into three chambers by means of two diaphragms, thereby sealing the center chamber that contains a snap-action switch. The two diaphragms are mechanically connected by a strut that can move only along a single line of motion, so that movement of one diaphragm is transmitted to the other. Movement of the strut is coupled to an actuator of the snap action to produce the desired switching action.

Abstract: Apparatus for detecting a sudden rise in pressure of a source thereof is disclosed which is especially useful for activating explosion suppression or isolation equipment by virtue of the fact that the apparatus is capable of detecting a sudden, incipient rise in pressure in a containment system which could result in a destructive overpressure in the system. The sudden pressure detection apparatus is provided with a housing having a pair of opposed passages defining fluid inlets closed with deflectable diaphragm means interconnected by a rod assembly having means thereon for operating a switch which controls activation of the suppression or isolation equipment. One of the housing inlets is adapted to be coupled to the source of system pressure. A pressure equalization conduit extends between and intercommunicates the housing passages to equalize the pressure on the diaphragm means.

Abstract: A normally open pressure responsive switch having upper and lower housings with a snap acting member and an electrically conductive member sandwiched therebetween. The housings each include a body with a hollow center portion and the lower housing has a contact in the center portion extending externally of the member. The snap acting member is in constant engagement with the sandwiched conductive member and normally out of engagement with the contact. When pressure is applied which is sufficient to cause the snap acting member to snap connection is made with the electrically conductive member in the lower assembly. An elastomeric sealing member is mounted in the upper housing and has a neck portion received in the hollow center portion, an integrally attached flange biased against the electrically conductive member and lower housing and an integrally attached lobe extending above the upper housing to seal off the hollow center portion when the switch is mounted at a switch receiving seat.

Abstract: A switch mechanism for controlling a motor that runs a well pump. Water line pressure acts on a diaphragm to pressurize an air chamber that communicates with a pressure switch. The switch components are isolated from the water line (by the air chamber), to minimize the possiblity of switch failure due to ice formation (winter time operations) or corrosion.

Abstract: A pressure sensor adapted for use in pressure switches, pressure detectors, pressure measuring instruments, etc. has a housing. The housing has at one end a force balance valve including a gas chamber sealed at one end by a valve diaphragm and filled with a pressurized gas, and at the other end a pressure receiving section sealed at one end by a pressure receiving diaphragm. The housing further has first and second cylinders with corresponding first and second pistons held in contact with the valve diaphragm and the pressure receiving diaphragm, respectively. Between the first and second pistons is provided a connecting member with an actuating section. The housing further has a working section which is actuated by the actuating section to provide an output or signal externally.

Abstract: A differential pressure responsive switch utilizes an operating diaphragm which has a position controlled by a pressure being monitored with the diaphragm acting through a transmission member upon an electrical switch and includes a first chamber divided by a control diaphragm and having an inlet for the pressure to be monitored to one side of the control diaphragm while the other side of the control diaphragm carries a closure member for an adjacent bleed valve seat. An inlet for the bleed valve is connected via a throttle to a source of a pressurized gas and to a second chamber defined by the operating diaphragm and a spring is engaged through the transmission member to urge the operating diaphragm against the pressure in the second chamber.

Abstract: An ignition system for projectiles, such as shells, bombs, or rockets is disclosed. The system has a pressure chamber defined by a double-diaphragm switch and a cap of a deformable material. The diaphragm of the double-diaphragm switch, which defines one wall of the pressure chamber, contains one or several perforations, the number and diameter of which depend on the spacing of the diaphragms, the areas thereof and the size of the pressure chamber. The double-diaphragm switch is connected to an electric ignition unit. An electrical circuit is closed only if a projectile housing a percussion fuse and the ignition system impacts on the ground or target after its flight. Any unintended ignition during firing or due to brief impact stress cannot occur.

Abstract: A fluid pressure switch includes a housing with a cylindrical bore, a spring housing bore and a guide bore between the cylindrical bore and the spring housing bore. A shaft member axially disposed in the housing between the bore, has a piston element secured on the end within the cylindrical bore for movement in one direction or another upon a differential between fluid pressure sources as presented to the two opposing surfaces of the piston element. A spring-biasing arrangement is secured to the shaft member on the end within the spring housing bore for opposing movement of the shaft member. The spring-biasing arrangement is adjustable both as to the spring force and as to the spring stop setting. A switch operator member secured to the piston member, spreads contact arms apart upon a predetermined displacement of the piston. The switch operator member has an elliptically-shaped eccentric portion which can be rotated to adjust the point of shaft displacement at which switch operation occurs.

Abstract: A relatively low cost, high performance pressure responsive switch device comprises a base, switch means mounted on the base, and a discrete pressure-responsive unit which is separately testable for predetermining its pressure response characteristics and which is then mounted on the base for moving the switch means between selected switch positions in response to the application of a selected fluid pressure. The discrete pressure-responsive unit is particularly adapted for achieving long unit cycle life under high operating pressure conditions and for actuating the switch means incorporated in the device to achieve long cycle life as well.

Abstract: A miniaturized differential pressure switch comprising a pair of matched square housing sections with a square diaphragm supporting a flat square diaphragm plate which bears against a compression spring that is flexed to open an electrical contact in dependence upon the pressure differential. The compression spring is removably mounted for exchange of springs to vary the range of operation of the switch. The housing section that defines the low pressure chamber provides means for mounting a heat sink that is used for the support of components required for an electronic relay. The switch is suitable for actuation by extreme low pressure, such as 0.01 inch water column.

Abstract: Apparatus is provided for assuring that fluid is introduced from a pump to a receiver, such as a patient, at a controlled and safe pressure. This arrangement includes conduit means, such as inlet and outlet lines, which extend from the pump to the receiver and which are included in a disposable unit. The disposable unit includes detent means cooperative with detent means in the pump to hold the disposable unit in releasable relationship with the pump.Resilient means such as diaphragm are disposed in the conduit means in the disposable unit. The resilient means expand or contract in accordance with the pressure of the fluid in the outlet line. Actuatable means such as an actuatable arm is disposed in the disposable unit and is captured in the conduit means and is positioned in abutting relationship with the diaphragm for movement with the diaphragm.

Abstract: A vacuum actuated switch has a pair of snap action contacts which are actuated in response to the operation of two vacuum motors. One vacuum motor controls the opening and closing of the contacts in a first predetermined range of vacuum. The other vacuum motor extends the range of operation to a second and larger predetermined range of vacuum wherein one limit of the second range is the same as the first range.

Abstract: A control switch unit adaptable for a number of different purposes has a fluid-filled flexible-walled capsule acting within a housing on a pivoted operating lever arranged to operate a switch located in the housing on the other side of the pivot axis of the lever from the capsule, the lever being biased by a cam-adjustable tensioning spring acting on the opposite side of the operating lever from the capsule and the switch. Further components such as a manual switch-off control, a pilot lamp operable by an auxiliary switch, or a capsule heater, can be added without rearrangement of the basic unit.

Abstract: A pressure responsive control device including a housing, a control switch unit and switch operating actuator, and a controller unit is disclosed for controlling operation of a refrigeration defrosting device. The actuator includes a bladder formed of thin film material which changes volume when a differential fluid pressure exists across the bladder. The bladder and switch unit are such that bladder volume changes are accompanied by minimal losses thus enabling the controller unit to be enabled in response to extremely slight differential pressures.

Abstract: A pressure actuated switch including a conductive frame forming a chamber having a pressure fluid inlet connecting thereto, a flexible diaphragm extending across the chamber to separate it into a first chamber connecting to the fluid inlet and a second chamber and where the flexible diaphragm mounts a contact means thereon which is movable into engagement with the second chamber wall when a suitable pressure differential exists between the chambers. A deformable member is positioned in the second chamber and is deformable by movement of the diaphragm towards the frame to bring the contact means into engagement with the frame so that the deformable member normally prevents contact closing action. Electrical connection means are present on the flexible diaphragm and extend from the contact means to a point remote from the frame, which connection means is insulated from the frame.

Abstract: An illuminating device having an L-shaped housing with a light source at each end, a diaphragm actuated switch for each light source, an air line in fluid communication with each leg of the housing, and a tube interconnecting the housing legs for permitting water to flow between the respective legs. The actuation of the switch is determined by the orientation of the housing and the flow of water between the respective legs.

Abstract: A differential pressure cutout switch including a low pressure operating point assembly and a high pressure operating point assembly which are mechanically linked and are operable to respond to first and second pressures supplied over respective first and second pressure inlets of the switch to control a contactor switch assembly which is movable to a first position to provide an open circuit between outputs of the switch and movable to a second position to connect a resistance of a finite value between the outputs as a function of the difference between the two pressures. The differential pressure cutout switch is described with reference to an application in a protection control system for monitoring lubrication oil pressure for a compressor of a refrigeration system.

Abstract: A pressure differential sensing device comprises a sealed housing having mounted therein a gas-filled flexible capsule and a switch operated by expansion of the capsule. The pressure differential sensing device is mounted to a pressurized chamber with the pressure of the chamber communicating with the interior of the housing and surrounding the capsule and monitors the chamber for gas leaks. The gas in the pressurized chamber and in the capsule both respond to variations in temperature in a like manner, and a relatively constant pressure differential is thereby maintained between the interior pressure of the capsule and the pressure of the housing. If gas leaks from the pressurized chamber, the pressure of the chamber decreases relative to the interior pressure of the capsule, and the capsule expands to operate the switch. Thus, the device is temperature compensated.The pressure differential sensing device is calibrated by adjusting the position of the switch relative to the capsule.

Abstract: A pressure switch for use in refrigeration systems which includes a restrictor to minimize the effect of compressor pulsations on the pressure sensing element and a heater positioned to warm the interior of the switch housing and to maintain the fluidity of refrigeration oil traversing the restrictor under conditions when the switch is exposed to low ambient temperatures.

Abstract: A differential pressure warning switch comprising a housing defining a chamber, hydraulic conduits communicating the master cylinder and front and rear fluid brake actuators of an associated vehicular brake system with the chamber, a shuttle piston movable within the chamber between opposed translated positions in response to differential pressure conditions existing between the front and rear brakes of the vehicle, and a pair of pressur responsive flexible diaphragm elements arranged adjacent the opposite ends of the shuttle piston and adapted to effect shuttle movement of the piston in response to predetermined differential pressur conditions in the brake system, whereby to complete an electrical circuit to an associated warning lamp or the like.

Abstract: A differential pressure module is secured in switching relation to the actuating plunger of an electrical switching mechanism. Comprising the differential pressure module are two piston/cylinder assemblies connected together in back-to-back configuration by secured cross members forming a floating yoke. Each of the assemblies includes a diaphragm in communication with a separate oppositely directed fluid inlet and through which a force differential effective from the separate forces acting in opposition to each other is applied via the yoke against the switch actuator. A cast body intervening between the assemblies defines the fluid inlets while maintaining the pressure of each isolated from the other.

Abstract: Apparatus is provided for assuring that fluid is introduced from a pump to a receiver, such as a patient, at a controlled and safe pressure. This arrangement includes conduit means, such as inlet and outlet lines, which extend from the pump to the receiver and which are included in a disposable unit. The disposable unit includes detent means cooperative with detent means in the pump to hold the disposable unit in releasable relationship with the pump.Resilient means such as diaphragm are disposed in the conduit means in the disposable unit. The resilient means expand or contract in accordance with the pressure of the fluid in the outlet line. Actuatable means such as an actuatable arm is disposed in the disposable unit and is captured in the conduit means and is positioned in abutting relationship with the diaphragm for movement with the diaphragm.