Abstract: An easily assembled, low cost pressure switch for a hydraulic pump is proposed. An oil pressure introducing hole is provided for leading a discharge pressure to a depression formed in a body which is earthed. A plug supporting an electrically conducting terminal in an insulated state so as to block the depression, comprises a cylindrical part opening into the depression of the body. An electrically conducting sleeve which is pierced by a damping orifice connected to the oil pressure introducing hole, engages with an opening of the cylindrical part. An electrically conducting plunger which comes in contact with and separates from the terminal in response to an oil pressure from the damping orifice, is housed in the sleeve. A spring pushing the plunger against the oil pressure is housed in the cylindrical part of the plug, and the lower end of the sleeve engages with the opening of the oil pressure introducing hole.

Abstract: A dispenser includes a plurality of beverage dispensing valves mounted thereto along a front end thereof Each valve includes an air switch that is pneumatically operable to turn its associated valve on and off. An equal plurality of air actuators are secured to an elongate panel hingedly secured to the dispenser front surface. Each air actuator includes a pressurized chamber and a pliable front surface. Flexible tubes extend between the air switches and the air actuators for communicating pneumatic pressure there between. The air actuators include a graphics layer secured to the front surfaces thereof. In operation, a front surface an air actuator is depressed manually whereby pneumatic pressure created thereby in the pressurized chamber is communicated by the tube thereof to its particular air switch. The air switch then serves to operate a solenoid of the valve with which it is associated, resulting in dispensing of the beverage.

Abstract: A safety module which is intended to be used in an oil or gas production installation and to be lowered to a required depth with an electrically operable tool connected thereto, and which comprises a housing (2), a pressure sensitive switch (3) and a temperature sensitive switch in the housing which are adapted to switch at predetermined pressure and temperature values respectively, in which the pressure sensitive switch and the temperature sensitive switch only allow an electrical command signal to be conveyed to the tool when the pressure and temperature both reach the predetermined pressure and temperature values.

Abstract: Systems and apparatus for integrating an air switch and a power cord into an electric motor, and methods for assembling an electric motor including an integral air switch and an integral power cord, are described. In one embodiment, an air switch and a power cord are incorporated into an electric motor. No additional removable cover is required for the switch and cord. To eliminate the motor centrifugal switch, an air switch is provided to control energization and de-energization of the motor windings. The air switch includes a snap action switch to cut-out the start winding used for ensuring that the rotor has sufficient starting torque.

Abstract: A water gun 10 having a storage tank (18), a pressure tank (19) and an electric pump (28) for conveying liquid from the storage tank to the pressure tank. The conveyance of liquid into the pressure tank causes the liquid to be pressurized by air compressed within the pressure tank. A safety switch (42) limits the pressurization of the liquid. The pressurized liquid is released through a nozzle (21) coupled to the pressure tank.

Abstract: An electrical circuit assembly (100) includes an electrically actuatable clamping arrangement (108) that provides a reliable, solderess electrical connection between two electrical circuits (104, 106). The present invention is readily adaptable for use with a first electrical circuit (104) that includes at least one electrical contact area (130) disposed on a substrate (102). The electrically actuatable clamping arrangement (108) is then used to provide an electrical connection between the electrical contact area (130) and a second electrical circuit (106).

Abstract: Pressure switch for moving an electrical contact arrangement including a switch frame supporting fixed contacts and movable contacts, the movable contacts being supported particularly on a contact carrier of the switch frame which is pivoted about a first axis. An intermediate rocking lever is guided on the switch frame and is pivoted about a second axis. A first spring arrangement biases the rocking lever upwardly, and a snap arrangement, containing a torsion coil spring, is interconnected between the rocking lever and the contact carrier. A transmission member, which is moved downwardly by a fluid pressure sensitive piston rod connected thereto, has rollers bearing upon the upper surface of the rocking lever and engages, after a certain downward movement thereof, with a second spring arrangement.

Abstract: A pressure switch comprises an electrically conductive housing, a stationary contact stationarily installed in the housing and a movable contact movably received in the housing. The movable contact is movable to contact with the stationary contact. A hydraulically operated moving device is employed for moving the movable contact in accordance with a hydraulic pressure applied thereto. The stationary contact is formed with a blind bore. An end piece to which an end of an electric cable has been connected is press-fitted in the blind bore.

Abstract: The present invention provides a pressure switch assembly for monitoring a source of fluid pressure. In one embodiment, the pressure switch assembly senses a variation of fluid pressure for actuation of a micro-switch to open or close an electric circuit. In another embodiment, the pressure switch assembly provides a self contained cluster of piston members which are selectively interengagable to permit a variety of pre-determined pressure ratings to act on the pressure switch assembly in response to a fluid pressure source, the cluster being manually reorganizable without adding or removing any parts to provide one valve assembly which may be responsive to a number of pre-selectable pressure ratings.

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 combination differential and static pressure switch utilized in a test system for detecting the occurrence of a differential pressure condition within the test system. The test system includes a valve assembly in flow communication with the pressure switch for determining the working pressure applied to a workpiece being tested. The pressure switch includes a first tubular-shaped member and a second tubular-shaped member axially aligned therewith and adapted for removable securement to the first tubular-shaped member. A differential piston is disposed for slidable reciprocal movement within the first tubular-shaped member and a preset piston is disposed within the second tubular-shaped member and is adapted for slidable reciprocal movement therein. Both pistons are axially aligned to each other, and the differential piston has a magnet mounted to the face end thereof.

Abstract: The pressure medium drive is provided for opening and closing the contacts (e.sub.1, e.sub.2) of an electric circuit-breaker. It contains a pressure medium reservoir (r), a drive piston (t) which slides in a drive cylinder (c) and acts on a mechanism (j) for displacing a movable contact (e.sub.1) of the circuit-breaker, and a reversing valve (s) for the selective connection of the pressure medium reservoir (r) to the drive cylinder (c) or of the drive cylinder (c) to an outlet volume for the pressure medium.This pressure medium drive is of simple, inexpensive construction and can open the contacts of the circuit-breaker considerably faster than it can close them.This is due to an interposed valve (v) which is disposed between the pressure medium reservoir (r) and the reversing valve (s) and has a flow cross section determined by the closing time of the contacts (e.sub.1, e.sub.2), and to the much larger flow cross section of the reversing valve (s).

Abstract: Apparatus for switching a high-current power supply, for example for transportable melting systems in melting and remelting plants, with a stationary apparatus part and a movable apparatus part, a contact surface between the stationary and the movable part as well as a device for locking the two parts, the contact surface (2d) on the stationary part (S) being preferably in the form of a hemisphere (2a) and the corresponding contact surface (3d) on the movable part (M) being preferably configured as a conical inside surface (3a) and the contacts being joinable forcibly with one another by means of a clamping device, the clamping device consisting for example of a centering and drawing bolt (2b) and of a corresponding ball clamping device, and that the clamping device is electrically insulated by means of insulators (7, 12) from the current-carrying contacts.

Abstract: A pressure responsive switch is shown having an electrically conductive body 12 formed with a bore 24 which extends from one side through the body into recess 30 formed in the opposite side of the body. A switch assembly 34 is received and locked in the recess by crimping downwardly extending wall 32 of the body over the assembly. The switch assembly has a terminal 35 formed with a stationary contact 36 on an end thereof mounted electrically isolated from an annular disc seat member 40 which in turn receives an electrically conductive disc member 56 and a flexible diaphragm 60. An elongated piston 64 is receivable in a port 18 of a pump and is slidably received in bore 24 of body 12 with an end 70 placed contiguous to the diaphragm 60 and center of the disc member 56.

Abstract: Holding device for a piston position detector, contained in a casing and being displaceably mounted on the outside of a fluid pressure cylinder. The holding device consists essentially of a U-shaped yoke being displaceable along two mutually parallel guides and being lockable in a desired axial position. The yoke is locked by means of a first fastening screw, whereas the casing is insertable between the shanks of the yoke and is lockable in inserted position by means of a second fastening screw. The casing is protected by the yoke and is detachable from the latter, also when the yoke is located to the guides.

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: The invention concerns a simple, inexpensive and small detector, particularly for use in the medical pumps, for detecting over-pressure in a pipe (1) and setting off an alarm when an over-pressure is detected. The detector for detecting over-pressure in the pipe (1) along which a fluid (3) flows may comprise a T junction (5) for deriving a fraction of the flowing fluid (3) from the pipe (1); at least one tube (7) wherein there is fitted at least one obturating member (9); and an assembly for detecting the displacement of the obturating member (9) in the tube (7) and for generating a signal in response to detecting displacement of the obturating member (9).

Abstract: A first belleville spring, having a given preload, controls a translatable, elongate, contact disc assembly, to cause a shunting disc to remove from, and close into contact with a pair of circuit contacts. The assembly is disposed within a translatable carriage, and a second belleville spring having a greater preload controls translation of the carriage, to cause the shunting disc to close into contact with, and remove from, a second pair of circuit contacts. As a consequence dual set points of switching operation is provided. A fluid medium, admitted into a housing for the assembly and carriage, effects translation of the assembly and carriage.

Abstract: The flow switch assembly (10) of a fluid power apparatus comprises a fluid flow pressure operated switch (10) which activates upon the failure or degradation of fluid flow. A body (14) contains therein a blind bore (15) which receives a piston (71) biased by a spring (17) located at the bottom (13) of the bore (15). A switch housing (11) which is molded about a contact (20) is threadedly inserted into an open threaded end (16) of the bore (15). The bore (15) communicates with a fluid flow opening such that fluid pressure causes the piston (71) to retract against the spring (17). The contact (20) extends axially beyond a wall (11A) of the switch housing (11) such that a radially enlarged portion (21) provides a seat for a seal (30) which sealingly engages the radially enlarged portion (21) and a surface of the bore (15).

Abstract: A pressure switch for operating a device for increasing the engine speed of an automotive vehicle equipped with a power steering system in order to prevent an engine stall when a high load acts on a power steering pump during parking and at a low vehicle cruising speed. The pressure switch is comprised of a movable terminal which is normally separate from a stationary terminal and contactable with the stationary terminal in response to an oil pressure over a predetermined level, in a hydraulic circuit of the power steering system. The movable terminal is slidably fitted in a pit to be filled with oil so that the response of the movable terminal to the oil pressure is lowered, thus providing a hysteresis effect to prevent chattering of the pressure switch.

Abstract: A spring strut including a work cylinder with a slider in the work cylinder. Electrical contacts are applied on the slider and cylinder and in an inward stroke, a first electrical loop, which extends via the slider, is electrically closed and a second electric loop is broken. In an outward stroke, the second electric loop is closed via the slider, and the first loop is opened. Thus, with the aid of an electrical circuit, it is simple and easy to recognize whether the work cylinder is operating in an inward or in an outward stroke.

Abstract: The present invention provides a pressure switch assembly for monitoring a source of fluid pressure. In one embodiment, the pressure switch assembly senses a variation of fluid pressure for actuation of a micro-switch to open or close an electric circuit. In another embodiment, the pressure switch assembly provides a self contained cluster of piston members which are selectively interengagable to permit a variety of pre-determined pressure ratings to act on the pressure switch assembly in response to a fluid pressure source, the cluster being manually reorganizable without adding or removing any parts to provide one valve assembly which may be responsive to a number of pre-selectable pressure ratings.

Abstract: In a rotary pump with a pressure switch, a pressure switch mounting space constituted by a small- and large-diameter holes is formed to be parallel to a rotating shaft in an end face portion of a front body to which a rear body is not joined. A pump outlet side fluid pressure is introduced to an inner end of the small-diameter hole. The large-diameter hole is connected to a pump inlet side. A plunger is slidably arranged in the small-diameter hole. The plunger is normally biased toward the inner end of the small-diameter hole and is kept movable toward the large-diameter hole depending on a magnitude of the fluid pressure of the pump outlet side. A pressure detector is operated when the fluid pressure of the pump outlet side exceeds a predetermined value.

Abstract: A fluid flow sensor for use with a fluid circulating system to indicate a predetermined rate of fluid flow therethrough, fluid flow sensor comprises a hollow fluid flow sensor body including a lower flow detection chamber and an upper fluid flow chamber formed therein and a float movable between a lower and upper position disposed within the hollow fluid flow sensor body, a float position sensing device including logic circuitry to selectively generate a first and second signal disposed adjacent the lower portion of the lower flow detection chamber and a float limit disposed within the upper fluid flow chamber, the float being disposed adjacent the float position sensing device when in the first position when fluid flow through the fluid flow sensor is less than the predetermined rate of fluid flow whereby the float position sensing device generates the first signal to indicate fluid flow of less than the predetermined rate and when the fluid flow through the fluid flow sensor equals or exceeds the predetermi

Abstract: The stored-spring-energy actuator mechanism (210) for the high-voltage circuit breaker (218) has a spiral spring (216) which can be loaded by means of the loading device (212). The high-voltage circuit breaker (218) can be switched on once and off once with the energy stored in the loaded spiral spring (216). The energy stored in the fluid-pressure accumulator (258) is sufficiently great to charge the spiral spring (216) at least once. The working-stroke movement of the piston rod (242) in arrow direction (A) is transformed via the gear segment (236) into a rotation through 360.degree. of the gear (232) meshing with this gear segment (236). The spiral spring (216) is thereby loaded via the loading lever (230).

Abstract: An improved pressure transducer having a switching device operated in response to changes in fluid pressure is disclosed which incorporates a terminal support member having electrical contacts which are designed to be electrically bonded to and mechanically interlocked with electrical contacts provided within the housing. The invention also includes an improvement in the piston contacts for preventing scratching of the resistor board. A method is provided for permanently connecting terminals of the housing with the mating metal connector terminals once they have been properly calibrated and connecting the housing ground strap with the terminal support member.

Abstract: The invention provides an explosively actuated switch and a method of using the same. The switch will include primary conductive elements which will remain generally stationary, and one or more movable conductive elements which will be clamped between the stationary elements. Various types of mechanisms may be utilized to exert a clamping force on one or more of the stationary members. An explosive material is provided to move the movable members from engagement with the stationary members upon detonation.

Abstract: A pressure responsive switch apparatus comprising a housing including a wall defining a passageway having an end adapted to communicate with a source of fluid under pressure, a switch supported by the housing, an actuator which is movably supported by the housing and which includes an end extending into the passageway, an actuator for actuating the switch in response to movement of the actuator, and a cup-shaped member detached from the actuator and located within the passageway and between the actuator and the end of the passageway for sealingly engaging the wall and moving the actuator away from the end of the passageway in response to pressure from the fluid source.

Abstract: A proximity switch assembly is provided which has a base with a longitudinal axis. A sensing coil is mounted on the distal end of a probe on a front axial end of the base, and the base is adapted to be mounted to a machine which has a moving part, the position of which relative to the sensing coil is to be determined by the proximity switch. An electrical cable connector is rotatably mounted on the base and may be rotated into a plurality of positions around the axis. Conductors extend between the sensing coil and the electrical cable connector, and at least part are deformed spirally to permit rotation of the cable connector. A series of teeth are on the base and a locking spring moves into engagement with any of the teeth to establish the plurality of locked rotational positions.

Abstract: The invention concerns an electrical reversing switch, which is especially suited for switching of high-frequency electrodes. This switch has an over mounted pneumatic cylinder, which moves on pistons arranged on both sides, and thus produces electric contacts.

Abstract: An electric switching device for making or breaking the electric continuity between electric connecting elements under the action of an external force includes, in a single case, at least one electric switch having a control member therefor, a movable operating member specific to each switch mounted in the casing for sliding movement along the switch, a tapping in each operating member having its axis parallel to the sliding direction of the operating member, and a rod threadedly cooperating with each tapping, each threaded rod having a first end on which the external force is directly exerted and a second end which can be rotated by an appropriate tool passing through a wall of the case, and the operating member comprises a substantially cylindrical sleeve acting against a coaxially mounted resilient return member, the sleeve having a member directly cooperating with the control member of the switch.

Abstract: A fluid pressure transducer with an electrical switch structure therein including a conductor which is movable relative to fixed contacts as influenced by the force of internal spring forces whereas the relative positioning of a spring's end in the housing is adjustable after the transducer's assembly thereby effectively calibrating the switch's opening and closing characteristics relative to a predetermined fluid test pressure.

Abstract: The invention relates to a control device for a circuit breaker. The circuit breaker is controlled mechanically by an engagement spring (8), by a disengagement spring (2), and by a hydraulic transmission for transmitting a portion of the energy in the engagement spring to the disengagement spring. The device has circular symmetry about a longitudinal axis.

Abstract: Length-adjusting device is provided on a switch, intended to indicate the shift of an object from a normal position. The switch comprises a fixed part, intended to be assembled securely in a chassis for example, and a switch part which is movable relative to the latter and which can be changed between different positions for switching the switch depending on the position of the object. The length-adjusting device comprises a first part, which interacts with the object in its positional shifting movements, and a second part which interacts with the movable switch part such that the said second part attempts to hold the movable switch part in one of its positions. The length-adjusting device comprises at least one fluid chamber which changes volume upon relative movement between the first and the second part.

Abstract: A combination oil pressure regulator and low oil pressure indicator for regulating the maximum oil pump pressure of a refrigerant compressor, and for providing a signal or indication when the oil pressure falls below a predetermined minimum value. The position of a piston in a housing is controlled by opposing forces provided by the oil pressure to be monitored and by a compression spring. When the oil pressure reaches a predetermined maximum value, relief apertures in the piston and housing establish a pressure relief path to the compressor crank case. When the oil pressure drops below a predetermined minimum value, the piston contacts and electrically grounds an electrically conductive element, providing a signal for associated control.

Abstract: Electrical contacts (10) and (12) are bridged by surface (22) when a fluid flow rate from fluid inlet (30) to exit (34) is sufficient to displace poppet (26) against the bias of bellows (28). Bellows (28) may be sealed at opposite ends to provide an environment for contacts (10) and (12) that is isolated from the fluid.

Abstract: An integrated switch-preaccelerator system for use in an electromagnetic launcher includes a pair of spaced generally parallel preaccelerator rails, a pair of spaced first and second conductive switch terminal elements disposed adjacent upstream ends of the rails, and three coaxially arranged conductive tubular members enclosing and extending axially along the rails, one of which being movable relative to the others between conducting and non-conducting positions.

Abstract: A pair of electrical switches are operable by a movable lever between a first condition where the first switch is on and the second switch is off, to a second condition where the first switch is off and the second switch is on, by movement of a piston connected to a pressure source via an inlet port. A flange is fixed on the piston shaft, and a compressed spring is mounted over the piston shaft between the flange and a sleeve surrounding the piston bore. A pressure close to ambient moves the flange which in turn moves the lever to the first position, while a pressure substantially less than ambient moves the flange in the direction to move the lever to the second position. The switches are adapted to respond to the pressure of the input manifold of a motor vehicle, actuating the vehicle headlight circuit when the motor is running and the manifold pressure is very high, and actuating the starter/ignition circuit when the motor is not running and the manifold pressure is at ambient.

Abstract: The electric and/or electrical sensor or detector device is intended to cooperate with a movable element surrounded by a shell, it comprises an annular clamping collar adapted to be clamped in position on a shell and connected to at least one connecting conductor, the collar carrying at least one mechanical and electrical removable member for connection to a removable detector element and the device is applied to a position detector to be quickly and removably secured onto a fluid cylinder body.

Abstract: A pressure sensitive switch has means for producing linear motion in response to pressure, means for springably resisting the linear motion, means for operating a switch after a predetermined linear motion, and a lifter pin having a projection on a first end for slidably engaging a hole in the means for springably resisting the linear motion, the lifter pin being mounted between the means for producing linear motion and the means for springably resisting the linear motion so as to transmit force from the means for producing linear motion to the means for springably resisting the linear motion, the lifter pin decoupling rotational motion between the means for producing linear motion and the means for springably resisting the linear motion. A piston may serve as the means for producing linear motion in response to pressure.

Abstract: A proximity switch for signaling the location of a movable member at either of opposite end limits of movement relative to a stationary frame includes a movable member, such as a piston, traveling along a fixed path of movement between a first position and a second position and having an aperture formed within the movable member extending from one end toward another end. A housing encloses a portion of the movable member to form a first fluid chamber between the movable member and a first end of the housing, and to form a second fluid chamber between a second end of the housing and the movable member. Expansion of the first fluid chamber drives the movable member to the first position and expansion of the second fluid chamber drives the movable member to the second position.

Abstract: A device for detecting the position of a movable element of an adjusting member operated by fluid pressure. A cylindrical probe is introduced into the wall of the actuator and extends to near the inner surface of wall. The probe is mounted to be axially displaceable at the holder so that it may be adapted to different wall thicknesses. The holder contains a sealing means for sealing the passage of the cylindrical probe, which is extended by the shaft and is adapted to be rotatable in a thread bore at the rear end of the holder. A circuit box accommodating the electric circuitry is secured to the end of shaft. The position detector, which detects when the piston has approached the probe, may be simply adapted to different cylinder wall thicknesses. This eliminates the requirement of using different types of position detectors whose probes vary by the length of their projection.

Abstract: A pressure switch wherein electrode plates are provided on both sides of a pressure conductive rubber plate. The pressure switch is interposed between a body and a receiving block slidably fitted to the body so that both electrodes may be connected with each other by connecting the rubber plate into conductive state to obtain an electric signal across the electrodes. The pressure applied to the rubber plate is regulated by a variable spring.

Abstract: A triple action pressure switch apparatus includes a housing having a pressurized fluid introducing path, the inner space of which is partitioned into a pressure actuating chamber communicated with the path and a switch mechanism storage chamber by a diaphragm. In the latter chamber, a third snap disc assembly, a first piston, a second snap disc assembly, a second piston, a first snap disc assembly, and first and second switches are arranged from the diaphragm in this order in a longitudinal direction of the housing. When the pressure of the pressurized fluid reaches a lower limit of a certain range of value, the first disc is transformed to set the first switch in one of ON and OFF states. When the pressure of the pressurized fluid reaches an upper limit of the range, the second disc is transformed to move a first tubular rod slidably inserted in the second piston and the first disc. Such movement of the first rod set the first switch in the other of ON and OFF states.

Abstract: A proximity switch for signaling the location of a movable member at either of opposite end limits of movement relative to a stationary frame includes a movable member, such as a piston, traveling along a fixed path of movement between a first position and a second position and having an aperture formed within the movable member extending from one end toward another end. A housing encloses a portion of the movable member to form a first fluid chamber between the movable member and a first end of the housing, and to form a second fluid chamber between a second end of the housing and the movable member. Expansion of the first fluid chamber drives the movable member to the first position and expoansion of the second fluid chamber drives the movable member to the second position.

Abstract: A portable air pump assembly and detachable safety lamp, includes an air compressor; an air supply line supplying pressurized air from the air compressor to a tire; an electrical supply line supplying current to the air compressor; electrical contacts which connect the electrical supply line to the air compressor only when they are in a closed condition; a by-pass air supply line having one end with the air compressor; a pressure limit switch connected with the opposite end of the by-pass air supply line for automatically causing termination of the current supply to the air compressor in response to back pressure from the tire when the tire has been inflated to a desired air pressure; and a safety lamp detachably connected with the housing for providing a warning light and operable in a connected or detached position.

Abstract: The invention comprises a pressure actuated switch which is actuated when the inlet port of the device is exposed to a preselected pressure. A piston size, and one or more shear pins, is selected for the desired operating pressure, the piston area being inversely proportional to the desired operating pressure. Shear pins are preferably of one size and material. When the desired operating pressure is applied, the force of the piston causes the shear pin to shear thereby allowing an electrical contact to complete an electrical circuit and initiate operation of a selected device such as a recorder, perforating gun, etc. If a single shear pin is used, with any selected piston and desired operating pressure, the shear force applied is a constant; i.e., for any given operating pressure and selected piston size with a single shear pin, the applied shear force is the same. If two shear pins are required, the applied shear force is doubled.

Abstract: There is provided a hydraulic pressure operated electrical switch having a spring biased piston which is movable by the force of the hydraulic pressure of the fluid to be sensed to activate a microswitch. The pressure required to move the piston can be altered by adjusting the force produced by the spring acting on the piston. An operating pressure differential is provided by a diaphragm which operates to move the piston by reason of the hydraulic pressure exerted thereon. The diaphragm has a spring rate and produces a force in conjunction with the spring bias against the piston when the piston is moved as a result of the hydraulic pressure overcoming the spring bias. The spring rate of the diaphragm is affected by the amount of hydraulic pressure exerted thereon so that, as a result of adjusting the operating pressure of the switch, the operating differential pressure is altered.

Abstract: A proximity switch adapted to be threaded into a pressure cylinder, with the proximity switch including a sensor part insertable into a bore or opening of a cylinder wall of the pressure cylinder for detecting a position of the piston. A housing of the proximity switch includes a metal casing for accommodating a sensor part of the proximity switch, a front cap for sealing the metal casing, an a housing section attached to the metal casing and including a cable connection portion. A continuously extending output collar is provided at a rear end of the metal casing, with the collar being adapted to be fixedly clamped against the cylinder wall by a mounting gland extending behind a rear face thereof or by a coupling ring.

Abstract: An electrical pressure switch is used on a hydraulic system to indicate the presence of a minimum operating pressure. The hydraulic fluid acts on a piston to move the piston against a force exerted by a calibration spring. Movement of the piston ultimately closes the contacts of a switch, thereby delivering an electrical signal indicative of minimum operating pressure. A check valve moves in concert with the piston and isolates the internal structure of the pressure switch from escalating hydraulic pressure.