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: A pressure switch element (1) including a semiconductor layer (3) having a diaphragm portion (5) in its center and a plate (2) having a through hole communicating with the exterior, which are stacked one on another so as to define a gas space (6) between the diaphragm portion of the semiconductor layer and the plate. The element (1) further includes an insulating layer (4) provided on the lower surface of the diaphragm portion (5), a first switch electrode (9) provided on the lower surface of the insulating layer (4), and a second switch electrode (10) behaving as a fixed electrode provided on the plate (2), such that chattering is prevented with a simple structure without using a complex electronic circuit.

Abstract: A short-stroke dome-shaped disc film spring comprising a dome-shaped portion and a skirt figure portion, wherein the cross section of the skirt figure portion rises in a line, the rise angel is inclined inward between 40 degrees and 60 degrees, the height of the skirt figure portion is between 0.2 mm and 0.4 mm, and the dome-shaped portion and the skirt figure portion are formed from a resin film of thickness 75 to 200 .mu.m. The dome-shaped film spring has a short stroke at which a feeling of a click is obtained.

Abstract: For protecting the pump of a carpet cleaner, the cut-out terminals 16, 15 are commanded by the pressure of fluid in passage 11, 12, 13 which communicates with volume 22 having as an upper wall a flexible diaphragm 24. A fluid tight and electrically insulating housing 9 has a fixed boss portion 19 which is surrounded by a mobile annular permanent magnet 25 carried by diaphragm 24 and which guides a central mobile permanent magnet 20 which drives a mobile contact 18 up or down, closing or opening terminals 15, 16. High pressure at 11 drives diaphragm 24 and magnet 25 upwards, which attracts magnet 20 upwards, and connects terminals 15, 16 via mobile contact 18.

Abstract: A panel-mountable pressure switch having an external adjustment lever has a mounting bracket with a right-angled flange attached to the switch housing. The bracket has a cam shaft rotatably mounted on the bracket for adjusting the lever position with the end of the shaft extending outwardly through the bracket flange. The panel has a non-circular aperture formed therein and a plurality of tabs formed on the bracket flange are inserted into the aperture and the bracket is rotated to secure the flange against he surface of the panel. A releasable locking tab on the bracket flange snaps into a separate aperture recess formed in the panel to prevent reverse rotation of the bracket and removal without user depression of the locking tab.

Abstract: The problem of providing plurality of different models of pressure switches to suit the requirements of a plurality of differing manufacturers may be minimized or eliminated in a pressure switch, including a frame (20), a diaphragm (50) secured to the frame (20) and adapted to be exposed to a mechanical source of fluid under pressure, such as a compressor, and electrical contacts (64), (66), (70) mounted on the frame (20) for relative movement toward and away from each other between open and closed positions. A lever system (72), (80) is mechanically interposed between the diaphragm (50) and the contacts (64), (66), (70) for effecting the previously mentioned relative movement and an unloader valve (110) is mounted on the frame (20) and adapted to be connected to the source of pressure fluid and operable when the contacts (64), (66), (70) are in an open position to vent fluid under pressure from the source.

Abstract: In the case of a switching element, a pressure-compensation element (20) is inserted in the base body (10) of the terminal strip (11) in a recess so that a pressure compensation is possible between the interior of the housing (17) and the outer atmosphere. By means of this special arrangement of the pressure-compensation element (20) in the terminal strip (11) it is possible to test the functional capability of the pressure-compensation elements in the installed state in a simple way without additional testing processes.

Abstract: A pressure operated switch construction, parts therefor and methods of making the same are provided, the pressure operated switch construction comprising a housing having an external surface and carrying an electrical switch unit and a diaphragm assembly therein, and a compression spring unit carried by the housing and being interconnected to the switch unit and the diaphragm assembly to control the operation thereof in relation to the compressive setting of the spring unit, the housing having a bracket member extending outwardly from the external surface thereof in a flange-like manner and having first structure for mounting a first movable actuator unit to the housing that is to be interconnected to the spring unit to select the desired compressive setting thereof, the switch construction comprising a bracket interconnected to a second structure of the bracket member, and a second movable actuator carried by the bracket and being interconnected to the spring unit to select the desired compressive setting th

Abstract: A pressure operated switch construction and method of making the same are provided, the pressure operated switch construction comprising a housing having an external surface and carrying an electrical switch unit and a diaphragm assembly therein, the housing having an opening passing through the external surface thereof, the switch unit having opposed sides and an opening passing therethrough in alignment with the opening of the housing, and a compression spring unit carried by the housing and being operatively associated with the switch unit and the diaphragm assembly to control the operation thereof in relation to the compression setting of the spring unit, the spring unit comprising a spring retainer operatively interconnected to the switch unit, an actuator carried by the housing and a compression spring having opposed ends respectively bearing against the actuator and the retainer, the retainer having an intermediate part disposed in the opening of the housing and having a surface and a projection extend

Abstract: An inner space of an outer case is partitioned by a gas permiable diaphragm into a fluid pressure operating chamber and a reference pressure operating chamber. The former chamber communicates with a pressurized fluid inlet hole formed in the case, and the latter communicates with a pressure equalizing hole formed in the case. Electrical contacts are stored in the latter chamber to perform on/off-operation in response to deflection of the diaphragm caused by pressure change of pressurized fluid in the former chamber. Outer connection terminals for the contacts are supported by the outer case. A filter is provided in the equalizing hole.

Abstract: A pressure switch (30) adapted to be placed within a pressurized chamber for generating a logical signal when the pressure within the chamber reduces to a determinable pressure P.sub.1. The pressure switch (30) comprises: a pressure vessel (32) sealed at one end (34) by a snap action diagram (40) and having an inner stop (42) and an outer stop (60, 62) respectively positioned on opposing sides of the diaphragm (40) for limiting diaphragm motion. The outer stop comprises: a first cylindrical portion (78), a first pair of parallel slots (80a, b) formed therein and a through bore (70, 72, 74) extending therethrough. A switch assembly is loosely mounted to the outer stop. The switch assembly (90) comprises an upper housing member (92), a lower housing member (94), first and second electrical contacts (96a, 96b) and a pin (98).

Abstract: A replaceable ink reservoir for an ink printer [means comprises a means to] prevent unauthorized refilling and includes[. This means can be composed of] a magnetic contact element [(13)] arranged in the ink reservoir or [can be composed of] a clack valve arranged in the delivery region of the ink reservoir.

Abstract: A pressure system has a pressure vessel holding gas under pressure and has a pressure responsive device arranged to be responsive to loss of gas from the vessel to provide a warning signal or the like corresponding to the gas loss. The device has two springs opposing movement of a device diaphragm in response to the gas pressure in the vessel, one spring being arranged to oppose diaphragm movement resulting from change in the gas pressure due to change in gas temperature from a selected temperature in accordance with the gas law, and the other spring being arranged to permit diaphragm movement to change position of a control to provide a signal corresponding to a gas loss when change in the gas pressure in the vessel decreases to a selected level at the selected gas temperature.

Abstract: A signal tube operated switch includes a contact arrangement which is moved from a first, open circuit position to a second, closed circuit position by a shock wave or pressure pulse initiated by a detonator. The switch is preferably an electric switch and in at least one embodiment includes a movable conductive piston consisting of at least one portion in continuous conductive engagement with the conductive signal tube. The other portion of the contact arrangement causes a change in the circuit after the contact arrangement is relocated to the second circuit closing position. Accordingly, the overall working efficiency of delay detonators is improved.

Abstract: A pressure switch comprises a diaphragm held between and insulating cap and a conductive body to form an atmosphere chamber by the insulating cap and the diaphragm, and a pressure chamber by the conductive body and the diaphragm; a fixed contact provided on the insulating cap; a movable contact, provided on the diaphragm, for contacting/discontacting the fixed contact to detect a pressure, in the pressure chamber, reached to a predetermined value; communication device, provided with the insulating cap, for communicating the atmosphere chamber with the atmosphere; and water proof device for covering the communication device to prevent water form intruding into the atmosphere chamber.

Abstract: A pressure operated switch construction and method of making the same are provided, the pressure operated switch construction comprising a housing having an external surface and carrying an electrical switch unit and a diaphragm assembly therein, the housing having an opening passing through the external surface thereof, the switch unit having opposed sides and an opening passing therethrough in alignment with the opening of the housing, and a compression spring unit carried by the housing and being operatively associated with the switch unit and the diaphragm assembly to control the operation thereof in relation to the compression setting of the spring unit, the spring unit comprising a spring retainer operatively interconnected to the switch unit, an actuator carried by the housing and a compression spring having opposed ends respectively bearing against the actuator and the retainer, the retainer having an intermediate part disposed in the opening of the housing and having a surface and a projection extend

Abstract: A pressure operated switch construction, parts therefor and methods of making the same are provided, the pressure operated switch construction comprising a housing having an external surface and carrying an electrical switch unit and a diaphragm assembly therein, and a compression spring unit carried by the housing and being interconnected to the switch unit and the diaphragm assembly to control the operation thereof in relation to the compressive setting of the spring unit, the housing having a bracket member extending outwardly from the external surface thereof in a flangelike manner and having first structure for mounting a first movable actuator unit to the housing that is to be interconnected to the spring unit to select the desired compressive setting thereof, the switch construction comprising a bracket interconnected to a second structure of the bracket member, and a second movable actuator carried by the bracket and being interconnected to the spring unit to select the desired compressive setting the

Abstract: A pressure operated switch construction and method of making the same are provided, the pressure operated switch construction comprising a self-contained subassembly comprising a switchblade structure having a generally coplanar flat body and having a terminal secured thereto and a projection secured thereto in spaced relation to the terminal with the terminal and the projection respectively having parts that are respectively disposed substantially transverse to the body and at opposite ends thereof, the housing having two slots therein respectively receiving the parts of the terminal and the projection therein to self-pilot the subassembly into its proper position in the housing, the terminal and the projection being secured to the housing to hold the subassembly in its proper position.

Abstract: A pressure activated threshold switch has two electrodes separated by a small distance across a cavity. One of the electrodes is made of a mechanically compliant material. As a uniform pressure is applied to the mechanically compliant electrode, a threshold is reached at which the electrode buckles under the applied load and makes contact with the second electrode thereby closing the switch. The switch exhibits mechanical hysteresis by subsequently opening under a lower applied load. The pressure threshold switch is fabricated using wafer to wafer silicon bonding along with conventional integrated fabrication steps. The techniques of integrated circuit technologies enable dimensional control to be very good and hence activation pressures are tightly controlled. The fabrication method exploits properties of wafer to wafer silicon bonding, such as residual pressure inside sealed cavities and plastic deformation of silicon.

Abstract: A resilient element such as a thin flat plate or disc spring, commonly known as a "Belleville" spring, which is capable of deflecting along an axis normal to its surface is modified to include an amplifying segment disposed in a central aperture in the form of an approximately "W" shaped strip connected at its ends to opposite positions on the inner margin of the central opening. The central portion of the "W" forms an inverted "U" which is subjected, after positioning within the central aperture, to torquing stress in the plane of the material to bring the ends of the open end of the "U" slightly closer together than the inner edges of the "U" nearest its closed end. One of a pair of switch contacts is mounted on the closed end of the "U" shaped portion of the device opposite another contact carried on the switch bases.

Abstract: In an anti-lock brake control system having a vacuum brake power booster and a tandem master cylinder, in which the brake pedal is controlled to be positioned forwardly of the initial return position during the anti-lock control mode. This is achieved by variation of the rate of delivery of an auxiliary pump as by switching the pump motor on and off by a switch actuated by the diaphragm of the power booster to provide a signal of the pedal position at the start of an anti-lock control phase. Various switching arrangements described include a Bowden-cable pulled by the diaphragm, a mechanical or an optical switch actuated by the rolling lip of the diaphragm, or an approach switch detecting the approach of the diaphragm and cam-assembly. The core (53) of the Bowden cable (54) is connected with the diaphragm plate (52) of the vacuum brake power booster. The core (53) moves the trigger cam (64). The switch (18) is actuated by the movement of the trigger cam (64).

Abstract: A pressure operated switch construction and method of making the same are provided, the pressure operated switch construction comprising a housing having an external surface and carrying an electrical switch unit and a diaphragm assembly therein, the housing having an opening passing through the external surface thereof, the electrical switch unit having opposed sides and an opening passing therethrough in alignment with the opening of the housing, and a compression spring unit carried by the housing and being operatively associated with the electrical switch unit and the diaphragm assembly to control the operation thereof in relation to the compression setting of the compression spring unit, the compression spring unit comprising a retainer operatively interconnected to the electrical switch unit, an actuator carried by the housing and a compression spring having opposed ends respectively bearing against the actuator and the retainer, the retainer having an intermediate part disposed in the opening of the ho

Abstract: A manometer device having an adjusting head, an adjusting screw attached to the adjusting head, and an electrically conducting plate. Electric wires are connected to the adjusting screw and the conducting plate; and to a control for a fluid driver. With this mechanism, the manometer communicates with a space with fluid pressure to be measured. The fluid pressure urges the conducting pressure damper plate upwardly into contact with the adjusting screw to cut off the current in the circuit of the fluid driver when the pressure in the space to be measured reaches the pre-set pressure.

Abstract: A pressure operated switch construction, parts therefor and methods of making the same are provided, the pressure operated switch construction comprising a housing having an external surface and carrying an electrical switch unit and a diaphragm assembly therein, and a compression spring unit carried by the housing and being interconnected to the switch unit and the diaphragm assembly to control the operation thereof in relation to the compressive setting of the spring unit, the housing having a bracket member extending outwardly from the external surface thereof in a flange-like manner and having first structure for mounting a first movable actuator unit to the housing that is to be interconnected to the spring unit to select the desired compressive setting thereof, the switch construction comprising a bracket interconnected to a second structure of the bracket member, and a second movable actuator carried by the bracket and being interconnected to the spring unit to select the desired compressive setting th

Abstract: A hydrostatic pressure sensor, one use for which is to initiate the automatic deployment of emergency marine safety equipment, when a specified depth below the water level is exceeded. The sensor uses a novel method of compensating for ambient air temperature and barometric pressure as a means of reducing the errors in depth sensing caused by changes in the above ambient conditions.

Abstract: A damping disk assembly for a gas damped deceleration switch forms part of a means for generating a vacuum to damp movement of a mass which is movable in response to deceleration. The damping disk assembly comprises a rigid damping disk, and a coaxial flexible damping disk with a diameter greater than the diameter of the rigid damping disk. The flexible damping disk comprises a flexible spring disk and a flexible sealing disk, and has an unflexed position in overlaying surface contact with the rigid damping disk.

Abstract: A wire wand is inserted into a pressure sensor perpendicular to the sensor's operating axis. The wire wand is fixed and adjustable at one end and driven at the other end by the sensor. The arrangement provides for deadband adjustment of a pressure switch.

Abstract: A manometer device comprising a pointer to be fixed on a scale, a screw to be used to fix the pointer, and a sliding carriage cooperates with the screw; a pair of contacts are bolted on the lower surface of the sliding carriage. The two contacts can be used to connected with a fluid driver, and there is a pressure induction mechanism under the contacts which has a needle to thrust the contact point. With this mechanism, the center of the pressure induction mechanism would thrust the contact point open to cut off the current in the circuit while the pressure in the space to be measured reaches the pressure demonstrated by the pointer, and then the fluid driver would stop to act.

Abstract: A control device, switch unit therefor and methods of making the same are provided, the electrical switch unit comprising a switch having a movable actuator, a lever pivotally carried by the switch unit and having one end adapted to be operatively interconnected to a movable part of a control device so as to be pivoted by the movement thereof, the lever being operatively interconnected to the actuator to operate the switch between the different conditions thereof in relation to the pivoted position of the lever, and a pair of mounting plates respectively having holding structure that hold the switch between the plates and respectively having pivot structure that pivotally mount the lever between the plates whereby the plates, the switch and the lever form a self-supporting switch unit.

Abstract: A high temperature pressure switch assembly for an explosion-proof enclosure used in hazardous atmospheres comprises an electrical control switch for a remote power source supplying electrical power to the enclosure, and a pressure responsive member which actuates the control switch to disconnect the power source in response to a small but abrupt pressure rise within the enclosure which indicates an explosion, severe electrical arcing or insulation pyrolysis therewithin.

Abstract: A fluid-actuated pressure switch for a four-speed automatic transmission system having a diaphragm to prevent fluid contamination of the electrical switch contacts and features a leakage path which eliminates air trapped within the fluid.

Abstract: The invention concerns an apparatus for dispensing measured quantities of a liquid or liquefied material, comprising first pumping means, capable of delivering a continuous flow of material, second pumping downstream from said first pumping means, said second pumping means being capable of delivering less than the amount fed thereto by said first pumping means, a recirculation line, connected to the line connecting said first and said second pumping means, said recirculation line being provided with a valve and means for compensating excess of material fed by said first pumping means, which means for compensating excess material are present in said connecting line, and can activate a switch for opening said valve. In order to obviate possible problems concerning contamination by microorganisms, and to provide longer production runs, the invention is characterized in that said means for compensating excess material comprises a membrane which is impermeable for said liquid or liquefield material.

Abstract: A pressure switch comprising a housing, a diaphragm that divides the inside of the housing into a pressure chamber and an atmospheric chamber, a switch portion mounted in the atmospheric chamber, and a resilient cap fitted over the housing. A porous filter is held between the housing and the cap. The diaphragm is actuated according to the difference between the pressures inside the chambers. The switch portion consists of a movable contact and a fixed contact, and is connected to terminals.

Abstract: A semiconductor integrated pressure transducer in which a semiconductor substrate incorporates a hermetically sealed system comprising a first chamber communicating with a second chamber via a capillary. The first chamber contains a fluid and has at least one portion of a wall in the form of a deformable membrane separating the atmosphere within the chamber from that external to the sensor. The second chamber contains a compressible gas and has rigid walls. The capillary is partially filled with electrically conducting liquid, and the liquid physically separates the fluid in the first chamber from the gas in the second chamber. The wall of the capillary is electrically conductive at least in two separated regions such that in use, at a predetermined external atmosphere pressure, the electrically conductive liquid makes contact with both electrically conductive regions thereby completing an electrical circuit.

Abstract: A pneumatically operated pressure switch for monitoring the air pressure in a tire is provided with a second switch in its housing capsule. The second switch is connected to an oscillating circuit. This second switch changes the oscillating circuit upon sensing a change in the gas pressure in the reference pressure chamber. This leads to an error indication to the driver, and thereby provides a self-monitoring pressure switch for monitoring the air pressure in a tire.

Abstract: A pressure responsive assembly including an actuator rod coupled to a pressure source through a rolling type diaphagm. The other end of the actuator rod is connected to a wiper assembly. A first part of the wiper assembly contacts a coil of resistance wire to provide a first signal indicative of the pressure. A second part of a wiper assembly moves into and out of contact with a switch contact pad as the sensed pressure crosses a predetermined threshold value.

Abstract: A pressure switch wherein the interior of a casing is divided by a partition into a fluid chamber fed with a fluid the pressure of which is to be detected, and a working chamber in which a switch mechanism is housed. A rod extends slidably through the partition, provided at its one end with a pressure-receiving portion which is adapted to receive a fluid pressure in the fluid chamber, and projecting at the other end portion thereof into the working chamber so as to change the switching mode of the switch mechanism in accordance with displacement, which occurs due to a fluid pressure applied to the pressure-receiving portion, of the rod to the end thereof which is on the side of the switch mechanism. Springs urge the rod towards the fluid chamber. The fluid chamber is further provided therein with a first spring member the force of which constitutes a part of the desired force of the rod-urging spring.

Abstract: A device for sensing pressure and temperature within the crankcase of a refrigerant compressor is adapted to protectively stop the operation of the compressor when temperature and pressure conditions within the crankcase permit existence therein of liquid refrigerant. The device utilizes a sealed vessel containing liquid refrigerant. The sealed vessel extends from a head portion downwardly into the crankcase fluid, and is provided with a pressure-displaceable membrane seal in the head portion. When the membrane expands due to high temperature within the crankcase, it causes closure of an electrical circuit. A pressure equalizing conduit equalizes the pressure between the crankcase and a chamber that surrounds said head portion.

Abstract: A high voltage vacuum-type circuit interrupter is disclosed that includes a single or one-piece ceramic insulating housing providing both the external solid insulation between a line terminal and a switch terminal and the external solid insulation between the line terminal and electrical ground. The ceramic housing is mounted on a metallic base by the wedging action of a spring disposed under tension on an exterior inclined surface at the lower longitudinal end of the insulating housing and on an interior inclined surface of the base. A solenoid operated toggle mechanism disposed in the base actuates an elongated operating rod that effectuates the opening and closing of a pair of switch contacts positioned in an evacuated ceramic casing that includes a relatively shallow recess formed about its internal periphery intermediate its longitudinal ends. A tubular metallic vapor shield is held in the ceramic casing by a plurality of metallic ring segments positioned in the recess.

Abstract: An electronic pressure responsive switch comprises an activating element and at least two sensors. The activating element and the sensors are arranged to be relatively displaceable with respect to one another whereby the sensors each generate signals when the activating element assumes a predetermined position relative to a respective sensor. The switch further has an elastic diaphragm having a first face exposed to pressure to be sensed and a reverse second face carrying either the activating element or the sensors. The diaphragm is deformable by the pressure whereby the relative position between the activating element on the one hand and the sensors on the other hand is varied as a function of the pressure.

Abstract: The present invention is directed to apparatus for sensing high and low liquid level for the purpose of controlling a circuit. As liquid rises, gas within a first communicating line to a differential pressure switch is relieved through a check valve to atmosphere. When the liquid rises sufficiently, the pressure within a second communicating line causes closure of the switch and the circuit. As the level of liquid recedes, the check valve closes and a vacuum develops in the first connecting line so that the switch and circuit remain closed until the liquid level is below the entry to the first communicating line. At that time, the liquid within the communicating line exits and the pressures are equalized to the switch which then opens thereby opening the circuit.

Abstract: A mechanism for the instantaneous tripping of an electrical contact in response to a progressive variation in applied fluid pressure. Contact is made by a conductive element movable along its longitudinal axis between an open position and a closed position. The upper portion of the interior wall of the contact element comprises opposed first and second sloping sections of substantially triangular cross-section having a side in common at their connection. A throttle is defined by the connection between the sloping sections. A cage member partially positioned within the conductive element is movable therein in response to the applied fluid pressure. The cage member includes a head portion having a channel therethrough perpendicular to the longitudinal axis of the conductive element. At least one ball is housed in the channel and is movable along the longitudinal axis of the channel and up and down the sloping sections in response to the movement of the cage member within the conductive element.

Abstract: A sewer line backup detection device and alarm are provided which can be installed in place of the cleanout access cap in a conventional sewer line. The device comprises a housing having male connecting threads adapted to fit standard female receptacles which have been used in the past to provide cleanout access to sewer lines, the housing containing alarm means or alarm transmitting means actuated by a pneumatic switch. The pneumatic switch is actuated by a flexible diaphragm which is fitted snugly onto the lower end of the housing which extends into the sewer line. In the event of a blockage of the sewer line, the blocked material exerts pressure on the flexible diaphragm which closes the pneumatic switch thereby setting off an alarm, either locally or at a remote location such as the dwelling from which the sewer line exhausts. The alarm system is utilized especially advantageously in combination with a detention tank located in the basement or lower level of a high rise building.

Abstract: A pressure-sensitive electrical switch is provided with a diaphragm which can be displaced against the action of a spring and which defines together with a supporting housing a pressure chamber. There is at least one outwardly projecting connection contact in the form of a contact pin. For mechanically mounting the housing of the switch there is provided at least one latching element comprising a latch for engagement in a receiving opening of a supporting board or print board or the like, the electric contact with the conductor paths of the printed circuit board being established by an electrically conductive pressure spring superimposed upon the pin-like outwardly projecting connection contact which spring in the latched position of the at least one latching element is urged into contact with the associated electric conductor path.

Abstract: A fluid pressure device for detecting two or more fluid pressure levels from a varied range of fluid pressure includes a housing having a cylindrical bore and a pressure inlet in communication therewith. A piston member is reciprocably movable within the cylindrical bore. A piston rod extends from the piston member and projects outward of the housing where a switch-operating arrangement is secured. The switch-operating arrangement includes an interlocking arm and a number of blocking elements corresponding to the number of switch devices to be operated. Guide slots formed in the interlocking arm allow adjustment of the position of the blocking elements, thus affecting a change in the operating points of the switch devices. Surrounding the piston rod within the housing is a multiple-spring arrangement which opposes the movement of the piston and which exhibits a nonlinear spring coefficient.

Abstract: A control device has a plurality of terminals each with a contact section arranged at different preselected elevations therein. Switch means is pivotally movable in the control device into electrical contacting engagement with one of the contact sections and also thereafter rockably movable into electrical contacting engagement with at least another of the contact sections.A method of operating a control device is also disclosed.

Abstract: A pressure switch including a diaphragm displaceable under pressure and a switch chamber containing a switch element responsive to the displacement of the diaphragm, the switch chamber further including a vent hole formed therein for communicating said switch chamber with the surrounding atmosphere, the vent hole being closed at one end by a porous filter having air permeability and water repellency, the filter extending outwardly from the surrounding walls of a holder.

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 differential pressure operated electrical switch construction and method of making the same are provided, the construction having a housing carrying a pair of substantially straight parallel terminals and an electrical switch for electrically interconnecting the terminals together under the control of an actuator that is responsive to differential pressure acting across the same. One of the terminals has an end provided with a substantially rectangular opening passing transversely and completely therethrough and defining a substantially straight interior edge of the one terminal and the switch includes a movable switch blade having one end carried by the other of the terminals and having another end disposed in the opening for engaging against the edge to thereby place the terminals in electrical contact with each other.

Abstract: An electromagnetically transparent fluidic operator for adapting a conventional, mechanically operated electric switch to remote, fluidic operation includes a non-metallic housing for being rigidly attached to the electric switch with a chamber in the housing aligned with a mechanical actuator of the electric switch and a non-metallic, expandable reservoir mounted by the housing. The reservoir includes a nipple rigidly attached to the housing and a deformable diaphragm forming a seal with the nipple and being disposed in the chamber close to the mechanical actuator. The reservoir is pressurized with fluid from a remote location causing the diaphragm to deform and the reservoir to expand thereby applying a positive pressure or operating force against the mechanical actuator to operate the electric switch.