Abstract: A low-cost, easy to manufacture and maintain pressure responsive switch. The switch includes a pressure responsive diaphragm made from latex rubber that is mounted in a housing base. An annular groove in the housing base communicates with an annular shoulder in a housing cover to compress an O-ring for forming upper and lower chambers, sealing the housing and securing the diaphragm.

Abstract: A pressure switch has a housing with an interior bore extending from one end to the other. A rod slidable within the bore and operated by external fluid pressure extends between a piston at one end of the housing and a mechanically operated electrical switch at the other end of the housing. A spring is disposed about the rod between a first stop on the rod and a second stop on the housing. The spring provides resistance against movement of the rod under external pressure. The resistance of the spring to movement is adjusted by a sleeve engaging the spring, with the sleeve threaded into the bore of the housing for movement longitudinally within the housing. The sleeve includes plural radially extending slots disposed around the sleeve. A port in the housing allows access to the sleeve and a cover is provided for the port. The cover includes a ring disposed around the housing and threaded onto the housing over the port.

Abstract: A pressure switch has a housing with a mounting bracket and a flexible diaphragm defining a wall of the pressure sensing cavity in the housing. Movement of the diaphragm operates an electric switch. The diaphragm is spring biased and an adjustment arm is frictionally mounted in a pair of guide surfaces on the mounting bracket. The arm contacts a cap on one end of the bias spring and is movable in the guide surfaces for adjusting the position of the spring cap for calibration. The mounting bracket is mounted to the housing by inserting a lug on the bracket in a recess in the housing and crimping a folded tab on the bracket to engage another recess in the housing. In another embodiment using a housing of all molded plastic, the adjustment arm frictionally engages a slot molded in the housing and is moved in the slot for calibration.

Abstract: A method for assembling a condition-responsive electric switch mechanism having a snap-acting bistable spring switch element. The switch mechanism is assembled substantially in its entirety except for the capillary tube. The switch mechanism is then calibrated without the capillary tube using air pressure. Following calibration, the capillary tube is sealingly connected to the bellows, the capillary tube and bellows are filled with the operating fluid, typically a refrigerant, and the capillary tube is sealed to capture the operating fluid within the bellows and capillary tube.

Abstract: A pressure switch assembly has a preassembled spring capsule assembled onto a deck structure with a snap switch thereon to form a subassembly which is snap-locked into the cup-shaped housing. A rotary cam drum is provided in the housing with an external shaft for changing the setting. An adjustment lever has a bifurcated portion nested about the inner periphery of the cam drum and a threaded external adjustment is provided for moving the lever position against the spring capsule for calibration. The pressure switch is completely assembled from one side of the housing.

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 housing (10), (54) defines a well which holds a diaphragm assembly (12). The diaphragm assembly has a stud portion (14) that extends through an aperture in the housing and is biased into the housing by a spring (16). The stud portion defines a channel (18) which is received in a slot between arms of a calibration plate (20). Movement of the calibration plate transverse to the axis of the stud portion engages a cam surface (24) to position the diaphragm, more particularly a dielectric button (34) which engages a switch control member (50). As a fluid in a bulb (32) expands, it causes the diaphragm to expand, moving the control member (50) and one end of spring portion (48) causing contacts (46, 52) to open. The temperature or degree of diaphragm extension at which the switch contacts open is adjusted by rotating a shaft (60). As the stem is rotated, a cam follower (76) and cam (70) interact causing a dielectric actuator (64 ) to change the bias force, hence pivot point, of spring elements (44).

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 pressure switch according to the invention combines a pressure chamber with diaphragm, plunger, spring-loaded switch mechanism and electrical contacts in a single compact assembly. According to one aspect of the invention, the terminal board of the pump motor is incorporated into the control switch housing, eliminating the need for wiring from the switch to the terminal board and enabling the switch to be mounted inside the wiring compartment of the motor. According to another aspect of the invention, a pair of opposing blades are used in the switch mechanism to eliminate side forces and decrease friction, improving accuracy and life of the switch. A simple set screw may be used with one of the switch blades, in cooperation with a stop associated with the other blade, to adjust the spring force and thereby control the pressure control differential.

Abstract: A differential pressure switch assembly for low pressure applications permitting accurate "in field" set pointing of same, comprising a capsulized instrument that includes housing high and low pressure sections defining in assembled relation a pressure cavity across which such sections mount a flexible diaphragm separating high and low pressure chambers, with the low pressure section mounting at a site on the low pressure section a snap switch unit of a size appropriate for such assembly, which unit has a projecting plunger therefor that has an end portion disposed in the low pressure chamber of the unit, with the assembly further comprising a pressure differential sensor disposed for effecting electrical switching of the snap switch unit when the pressure of the assembly high pressure chamber exceeds that of the low pressure chamber by a predetermined differential.

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: An actuator having a spring biased button abutting a first electric switch operator button and a flange spaced from an operator button of a second electric switch is driven by a pressure sensing bellows against a Belleville snap spring, the actuator moving abruptly against an intermediate stop upon breakover of the snap spring to operate the first switch, the bellows subsequently driving the actuator and intermediate stop coincidentally against a second Belleville snap spring, and the actuator moving abruptly against a second stop upon breakover of the second snap spring to actuate a second electric switch and depress the spring biased button. Adjustment means are provided for adjusting the range for each Belleville snap spring to provide distinct pressure set points and independent electric circuits, and to adjust both set points simultaneously.

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: An integral housing and body case contain a diaphragm having one side exposed to an external signal pressure and another side exposed to a chamber in the integral housing and body case so that the diaphragm is able to flex in response to a pressure differential between the sides thereof. A rod in the integral housing and body case is movable in response to the flexure of the diaphragm and loosely carries a movable contact which can engage at least one fixed contact in the integral housing and body case. A first spring biases the movable contact toward the at least one fixed contact so that when the rod is moved by a signal pressure, the resulting movement of the movable contact causes the movable contact to engage with the fixed contact and be maintained thereagainst by only the force of the first spring.

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: In a preferred embodiment, a fluid-operated switch continuously and selectively adjustable over both a pressure range and a vacuum range. The switch includes a diaphragm enclosed in a housing, a first side of the diaphragm communicating with the fluid. On the second side of the diaphragm, actuator means are provided which actuate an electrical switch when the diaphragm is flexed by changes in the pressure or vacuum of the fluid. A main spring provides adjustable resistance to motion of the actuator means in the direction of diaphragm flexure corresponding to an increase in pressure, while a counterspring provides resistance to motion of the actuator means in the direction of diaphragm flexure corresponding to an increase in vacuum. Adjustment of the set point of the switch is effected through adjusting the degree of compression or relaxation of the springs by adjusting a threaded bonnet on the housing.

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: Disconnection of a fluid conduit from a fluid fitting 38 and electrical conduit from apertures 28 in a fluid pressure sensing switch when servicing is required is avoided in a construction wherein a switch module 12 is secured to a base 10 mounting a fluid pressure receiving fitting 38 and electrical conduit receiving apertures 28 by only two threaded fasteners 24, allowing the module 12 to be separated readily from the base 10 without disturbing conduit connections.

Abstract: A multi-stage pressure-to-electric switch assembly includes a top casing provided with a pressure receiving chamber, a bottom casing integrally secured to the top casing in closing relation to the pressure receiving chamber, and a diaphragm clamped between the top casing and the bottom casing to be in sealing, closing relation to the pressure receiving chamber. This diaphragm is provided with three spaced-apart pressure response switch control portions, each portion including a switch control button. Three two-position electrical switches are fixedly supported with respect to the bottom casing. Three hollow, externally threaded switch control sleeves are aligned between the diaphragm control buttons and the switches. A switch operating control nut is threadably mounted on each of the switch control sleeves, and a switch operating plunger extends through each control sleeve between the diaphragm button and a switch.

Abstract: A pressure sensing device associated with a motor vehicle tire is able to signal a lowering of the tire pressure below a minimum value or a raising of this pressure above a maximum value, these minimum and maximum values being adjustable separately.

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 pressure switch device for use in an air-conditioning system, specifically a three stage device capable of switching, for example, a combined low/high pressure switch, and an on/off switch for activating compressor and condenser elements of the system, respectively. The device includes an operating chamber, a yieldable plastic membrane having roll membrane faces for transmitting system pressure level changes to pistons, a leaf spring disc and levers activating pairs of switching contacts. Upon application of three different operating pressures, each of the pistons transmitting a different pressure level, the levers and lever joints having tension springs, operate to bias the switching contacts to open and closed positions, thereby activating or deactivating the system elements.

Abstract: A pressure switch assembly includes an electric switch which is actuated in response to a preselected pressure in a pressure line. The assembly includes an activating rod which is engageable with the electric switch. The activating is acted upon by opposing forces from the pressure and a spring. The spring bears against a stop ring which is threadedly mounted so as to be displaceable in order to adjust the spring force. The stop ring is rotated by rotating a cover portion of the switch housing, the cover being connected to the stop ring. Thereafter, the cover is locked against rotation.

Abstract: An electric circuit controlling device has a housing and snap action means for discrete snap action movement between a stable configuration and an unstable configuration thereof. Means is provided in the housing for seating the snap action means, and means is also provided for urging the snap action means from the seating means. Force transmitting means is operable generally for initially moving the snap action means into seating engagement with the seating means and for thereafter effecting the discrete snap action movement of the snap action means from the stable configuration toward the unstable configuration thereof.

Abstract: A fluid bulb-sensing type thermostat having a capillary tube from the sensing bulb connected to an inlet port of a fluid pressure sensing chamber defined in part by an expansible diaphragm which moves in response to fluid pressure in the chamber from the bulb to actuate a snap-acting switch. The diaphragm is mounted on a plate which is cantilevered from the thermostat housing, and the at-rest position of the plate with respect to the housing is adjustable by a cam against which the free end of the plate is biased, for calibrating the thermostat.

Abstract: A pressure-operated electric switch assembly of the diaphragm type wherein a housing mounted diaphragm actuates a snap action switch adjustable in the housing to vary the switch operating pressure. The pressure setting may be varied externally by the user upon manual rotation of a switch sealing boot and the setting may be visually observed from indicia surrounding the housing that cooperate with a pointer on the boot.

Abstract: An interlock switch mounted in the end of a hydraulic slave cylinder adapted to operate the release mechanism of a motor vehicle mechanical clutch, the slave cylinder being hydraulically connected to a master cylinder having an input member operable by the motor vehicle clutch pedal. The switch is adapted to close the motor vehicle starter relay circuit for a position of the slave cylinder output member corresponding to full release of the clutch, such that the clutch must be fully released in order to allow starting the motor vehicle engine. Preferably, the switch takes the form of a pair of concentric sleeves, each carrying appropriate contacts for closing the circuit, one of the sleeves being reciprocable in unison with the slave cylinder output member, and the other sleeve being automatically adjustable for initial position adjustment and for subsequent readjustment to compensate for wear of the clutch, such that closure of the switch always corresponds to a full release of the motor vehicle clutch.

Abstract: A method for protecting a compressor by reducing the differential pressure from the inlet to the outlet of the compressor by turbo-charging the inlet plenum of the compressor to reduce the normally present vacuum condition in the inlet, vacuum being simply a sub-ambient pressure. However, the inlet plenum is not increased to a pressure above ambient. Additionally by preventing a high vacuum condition from existing at the inlet plenum of the compressor by warning or even stopping the compressor if the vacuum reaches too great a level.

Abstract: A pressure switch for detecting and controlling small pressure gradients in fluid circulation systems includes a containing body having first and second channels formed therein, and an elastically deformable diaphragm. The diaphragm is supported at its edges by the body and separates the first and second channels from each other. A small disc formed of an electrically conductive material cooperatingly engages a portion of one of the faces of the diaphragm. Electrical contacts are supported by the body and disposed adjacent the small disc. The diaphragm is provided with a working portion that is disposed outwardly from the periphery of the small disc and is relatively thin. The pressure switch further includes an annular supporting plug projecting from the containing body and engaging the diaphragm close to the edge of the disc.

Abstract: An electrical circuit controlling device has a housing with snap action means therein adapted for successive discrete snap action movements. Means is movable in the housing for selectively transmitting a force at different preselected levels onto the snap action means to effect the successive discrete snap action movements thereof. An actuating member is movable in the housing and rockably engaged between the snap action member and a pair of switch elements to successively operate them between circuit controlling modes in response to the successive discrete snap action movements of the snap action means, respectively. A method of operating an electric circuit controlling device is also disclosed.

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: The electrically operated clutch controlling operation of the compressor is regulated by a damped pressure switch. The pressure switch has a diaphragm which moves in response to pressure variation to actuate the switch. The force acting on the diaphragm is opposed by spring force. The housing is provided with a damping chamber between the diaphragm chamber and the restricted passage in the inlet. The restricted passage is the clearance between the hole drilled in the metal insert and the wire fixed in the hole. The restriction is selected relative to the damping chamber so the switch will not cycle more than four times per minute when sensing pressure at the outlet of a finned coil evaporator in an automotive air conditioning system operating under light load.

Abstract: A thermostatic switch unit for controlling a freezer or, for example, refrigeration apparatus in automotive air conditioning, includes a switch (1) which is acted upon by a thermostat mechanism responsive to the working temperature of the evaporator so as to maintain this temperature within a normal working range which is presettable by means of a control knob (18) in a conventional manner. By depressing manually a push button (26) mounted centrally in the control knob a spring loaded trip lever (29) is rotated to release a spring loaded lever (35) into engagement with a switch operating plunger (2, 3), closing the associated switch contacts (21) and causing the compressor motor of the apparatus to run until a low temperature, below the preset working range of the equipment, is reached, when the latch mechanism (29, 35) is reset automatically by the temperature sensing bellows (8) acting through the operating lever (4) of the thermostat mechanism.

Abstract: The conical tip of a load applying member (42) acts against one side (136) of a movable plate (120). A spring (84) urges the conical tip of a biasing member (88) against the other side (138). In response to a relatively small movement of member (42) against plate (120), plate (120) pivots about a first axis a.sub.1 to depress the operator (102) of a first snap-action switch (98). In response to a relatively large movement of member (42), plate (120) pivots away from contact with operator (102), first about auxiliary axis a.sub.4 and then about third axis a.sub.3. In response to an intermediate movement, plate (120) pivots to depress the operator (103) of a second snap-action switch (99), first about second axis a.sub.2 and then about auxiliary axis a.sub.4. Axis a.sub.4 is defined by first and second fulcrums (71, 134). Axis a.sub.2 is defined by second fulcrum (134 ) and operator (102); axis a.sub.3 is defined by first fulcrum (71) and operator (103). Axis a.sub.

Abstract: The electric circuit controlling device has a snap acting member disposed in a housing and is adapted for successive discrete snap action motions from a stable configuration toward two unstable configurations. A pair of means are operable generally for switching between two circuit controlling modes and an actuating means is operable generally in response to the successive discrete snap action movements of the snap acting member for selectively operating the pair of switch means between the circuit controlling modes. A force transmitting means has at least two different force applying portions selectively associated in operating relation with the snap acting member to cause the successive discrete snap action movements from the stable configuration toward the two unstable configurations at different force levels. The device is provided with an adjusting arrangement wherein the magnitude of at least one of the two different force levels can readily be changed.

Abstract: A control device has a housing, and structure disposed in the housing is generally operable for switching between a pair of switching modes thereof. A pair of snap action discs arranged in the housing in opposite and engaging relation with each other are operable relatively and conjointly through discrete snap action movements for effecting the operation of the switching structure between the switching modes thereof. A diaphragm-piston assembly is operable generally for transmitting an applied force in only one direction onto the snap action discs to effect the relative and conjoint operations of the snap action discs through their discrete snap action movements thereby to operate the switching structure between the switching modes.

Abstract: Increasing pressure acting under the thin plastic film diaphragm will move the actuator upward against the force of the outer reset spring until the upper inside washer/seat engages the outer washer/seat causing the inner trip spring to be compressed with further upward movement. Thereafter, switch actuation is opposed by both springs and the trip force is determined by both springs. As pressure decreases after the switch has tripped, the inside spring seat engages the shoulder on the actuator so only the reset spring is effective to determine the reset force. Both springs are assembled on the actuator prior to assembly in the pressure switch. The terminal structure is novel in the way it is positively located and accurately locates the switch.

Abstract: An apparatus to continuously monitor a preset altitude for a pilot of an aircraft. It senses a change in altitude and an audible as well as a visible alarm tells the pilot that he has deviated from his preset altitude by a given height. Increase in altitude is signaled by a high pitch tone and by a yellow light while a decrease in altitude is signaled by a low pitch tone and a red light. The invention can also be used to warn a small boat operator of a pressure drop.

Abstract: A push button actuator for an electrical switch device is disclosed which provides high tactile feedback with small button travel. Movement of the push button is resisted by a resilient column extending between the button and a force transfer device which is adapted to laterally engage the column in response to a sufficient force applied to the force transfer device through the column. The lateral engagement initiates buckling of the column which sharply reduces its load bearing capacity and causes the push button to snap to its depressed position.

Abstract: A control device has a housing with a chamber therein, and a pair of means is mounted to the housing within the chamber for supporting a first contact and a switch having a resilient switch blade with a second contact engaged with the first contact. The supporting means include at least one deformable section, and a pair of adjusting means are adjustably movable in the housing to affect the deformations of the at least one deformable sections of the supporting means thereby to locate the first contact in an adjusted position defining a force required to break the first and second contacts upon actuation of the switch and to bias the switch blade toward another adjusted position defining another force required to remake the first and second contacts upon the actuation of the switch.

Abstract: A pressure switch having a movable bellows (14) in a pressure chamber (12), a first electrical contact (16) movable with the bellows, a three-dimensional cam (18) and a second electrical contact (20) resiliently biased to follow the cam. In the preferred embodiment of the invention, the cam has a radius that linearly increases with the angular position of the cam, and is tapered toward one end for all regions about its periphery except at a point of maximum radius. Calibration at low pressure is effected by rotating the cam to its maximum-radius point, applying a standard low pressure to the chamber (12) and rotating the chamber about a threaded coupling (26) until the contacts (16) and (20) are at the point of closing. Calibration at high pressure is effected by rotating the cam to its minimum-radius point, applying a standard high pressure to the chamber, and adjusting the axial position of the cam until the contacts are at the point of closing.

Abstract: A latching mechanism for a reciprocable actuating means which has a short linear reciprocable stroke between two opposed positions at opposed ends of the actuating stroke. The actuating means is designed for operating an electrical shunt switch useful with electrochemical cells. The latching mechanism operates to maintain the switch contacts in either the open contact or closed contact positions until a positive unlatching force is applied to permit movement of the contacts.

Abstract: A switch which is actuated when a preselected fluid pressure differential is exceeded. A piston exposed to the pressure differential carries a plunger which contacts a lever arm mounted on a shaft. A spring normally prevents the shaft from turning but is overcome when an excessive pressure differential is applied across the piston. A switch arm mounted on the shaft actuates the switch in response to turning of the shaft.

Abstract: A pressure limiting switch is provided for limiting the upper and lower limit values of the air pressure in a circuit feeding pneumatic controls. The switch has a switching arm which is pivotable at one end around a fixed axis in the switch body and adapted to actuate with its other end a microswitch closing a valve in the circuit if necessary. The air pressure is sensed by a movable element which engages the switching arm between the pivot axis and the microswitch. The switching arm is spring biased for compensating the microswitch spring. The air pressure range is adjustable through adjusting discs serving as abutments for movement of the switching arm.

Abstract: A sensor responsive to a differential pressure between a fluid in a reservoir and the surrounding environment for operating a switch to activate and deactivate a pump and maintain the pressure of the fluid in the reservoir within a predetermined range.

Abstract: A vacuum switch in which the diaphragm movement with increasing vacuum is opposed by two springs which determine the vacuum required to actuate the switch. As the vacuum subsequently decreases one of the springs is rendered inoperative before the switch resets so the reset vacuum is determined by the one spring remaining effective. The spring which is rendered inoperative is compressed between the actuator and an eyelet which can seat on the actuator (spring ineffective) or the housing (spring effective) and which also functions to limit motion of the actuator relative to the eyelet so the switch operated by the actuator cannot be overstressed.

Abstract: An electric switch actuated in response to a condition, such as the occurrence of a particular pressure level, is shown to comprise a base having a switch receiving chamber and having an open end closed by a snap-acting diaphragm assembly. A motion transfer pin is slidably mounted between the diaphragm and a movable contact arm to transfer motion from the diaphragm to the arm. The diaphragm is supported on an annular plate used to prevent over pressures from deleteriously effecting the diaphragm and may be used in forming and calibrating the diaphragm for snapping in one direction. An adjustable spring is disposed on the other side of the diaphragm to permit calibration adjustment of the diaphragm for snapping in the opposite direction. The spring is mounted in a housing adapted to be connected to a pressure source. The switch is weatherproofed by providing a skirt which depends from the housing and extends toward and beyond the base.

Abstract: A water level control device having a cam follower for setting the desired water level setting for the control device and a movable cam member having a cam surface engaging the cam follower to set the same in desired positions, the cam surface having a reset portion for resetting the control device when the reset portion is disposed against the cam follower. The cam member has an integral spring that cooperates with the control device to tend to move the cam member from its resetting position when the reset portion is disposed against the cam follower, the cam member and spring being homogeneous and thereby comprising a one-piece homogeneous structure.

Abstract: A push switch construction with an adjustable switching point which includes a piston or membrane adapted to be pressurized by a pressure medium and to actuate a switching element against an action of a restoring spring when a predetermined switching point is reached. The piston or membrane is operationally linked with a pivotably mounted switch lever which is adapted to actuate the switching element. The switch lever is tensioned by a leaf spring through a counter bearing displaced lengthwise relative to the switch lever in a direction opposite to a torque exerted by the piston or membrane.

Abstract: A variable pressure control switch for a battery charging circuit is provided which includes a housing that receives a first member. A chamber is provided in the first member and a diaphragm extends across the chamber to divide the chamber into first and second portions. A first passage communicates with the chamber first portion and extends through the first member and is adapted to be connected with the interior of the battery to be charged so that the interior pressure of the battery is applied to the diaphragm. A second passage is provided in the first member which communicates with the chamber second portion and a piston is slidably received in the second passage. The piston is movable by the diaphragm between a first and a second position. Variable force biasing means engages the piston to prevent movement of the piston to the second position until a preset pressure has been exceeded.