Abstract: A method for the detection of restricted airflow to a smoke sensor in a central detector unit of an aspirating smoke detection system. An aspirator of the detector unit draws air into the central detector unit along a plurality of sampling pipes. A first portion of the air is directed along a sensing conduit via a filter to the smoke sensor, whilst a second portion of the air continues along a primary conduit and is not directed through the smoke sensor. A first flow meter is positioned on the sensing conduit, and a second flow rate meter is positioned on the primary conduit. A ratio of the flow rates measured by the first and second flow meters is calculated, and used to determine that the filter is restricting airflow to the smoke sensor when the ratio exceeds a predetermined threshold.

Abstract: Detailed are actuators especially useful in connection with valves forming parts of water-recirculation systems of pools or spas. Transit times of components of the actuators may be measured or otherwise determined and signals sent to the actuators to cease movement of the components between boundary positions. Consequently, dynamic adjustment of the valving capabilities of the systems may be achieved.

Abstract: A gas appliance monitoring apparatus for automatically detecting and alerting to a “gas-out” condition of a gas appliance during operation, and/or for alerting to the presence of prolonged “gas-on” conditions of an appliance. The apparatus utilizes a highly sensitive low loss and low flow gas flow indicator with multiple flow sensors to monitor the gas flow characteristics of the appliance during use. A gas flow analyzer and alarm timing mechanism analyzes the gas flow characteristics and sounds an alarm at the appliance or wirelessly at a remote location upon detection of either of the above conditions. A biasing attraction magnet is incorporated in the fluid flow indicator to offset either the force of gravity or a return spring in low flow/low pressure applications. The piston is sealed for use in high pressure/low flow applications, and provided with a vent hole for residual gas bleed-off upon a stoppage of gas flow.

Abstract: A method for fire detection in enclosed environments (1) subject to explosion protection regulations out of which an air-dust mixture is filtered while the concentration of dust of the air-dust mixture is lowered to under the explosion limit by a filter (2) and the aspirated air-dust mixture is checked for burning characteristics and if appropriate a fire alarm is triggered, in which the function of the filter (2) is monitored, the fire detection is carried out by use of an aspirating smoke detector system (7) not approved for use in potentially explosive areas but instead is deployed outside the ex-zone and if the filter (2) is destroyed a signal processing unit (15, 15.1) of a malfunction monitoring sensor (14) generates a signal which initiates a subsequent action preventing aspirated air-dust mixture with an elevated concentration of dust from entering the aspirating smoke detector system (7).

Abstract: A water flow detector has a spring driven mechanical timer responsive to the movement of a lever. The lever is connected to a paddle. The paddle is responsive to the flow of water in a pipe. The detector via the spring driven timer responds to the flow of water in the pipe after a predetermined delay.

Abstract: A flowmeter method and system. In an implementation, a signal is received from a flowmeter and a value is determined based on the signal. The value is compared to a threshold. A heartbeat value is provided when the value is greater than a threshold value. In some implementations, a flow rate of a fluid is based on the heartbeat value. In some implementations, the heartbeat value is monitored and an alarm is selectively generated based on the monitoring.

Abstract: A highly sensitive low loss and low flow fluid flow switch is coupled with an automatic timer and/or optional transmitter to indicate the flow of gas to an appliance and to automatically start a reminder timer to turn the appliance off. After a preset time limit has expired, the timer either sounds an alarm or wirelessly triggers an alarm in a remote location. The receiver portion of the wireless timer may be mounted directly to the appliance (grill handle), so that the timer automatically resets when activity (cover opening or closing) is detected, indicating the appliance is still in use. An alarm can also be configured to sound when the grill is attempted to be ignited with the cover closed, thereby avoiding a potential explosion. A biasing attraction magnet is incorporated in the fluid flow switch to offset either the force of gravity or a return spring in order to extend performance to low pressure and low flow applications.

Abstract: A highly sensitive low loss and low flow fluid flow switch is coupled with an automatic timer and/or optional transmitter to indicate the flow of gas to an appliance and to automatically start a reminder timer to turn the appliance off. After a preset time limit has expired, the timer either sounds an alarm or wirelessly triggers an alarm in a remote location. The receiver portion of the wireless timer may be mounted directly to the appliance (grill handle), so that the timer automatically resets when activity (cover opening or closing) is detected, indicating the appliance is still in use. An alarm can also be configured to sound when the grill is attempted to be ignited with the cover closed, thereby avoiding a potential explosion. A biasing attraction magnet is incorporated in the fluid flow switch to offset either the force of gravity or a return spring in order to extend performance to low pressure and low flow applications.

Abstract: To enable an air velocity of sampling air to be precisely measured, a smoke detector (S) includes: a smoke detection part (22) connected to a sampling pipe (11); a fan (12) that sucks sampling air (SA) into the sampling pipe; and an air velocity sensor (15) that measures an air velocity of the sampling air within the sampling pipe. The air velocity sensor (15) is disposed at a primary side of the fan (12), and a straightening vane (25) is disposed between the air velocity sensor (15) and a suction port (12a) of the fan (12).

Abstract: The disclosed invention relates to detecting a flow condition in a fluid supply system. The invention is particularly useful for detecting flow in a toilet system. The flow detection device comprises a processor associated with a flow sensor. Predefined flow criteria are stored in a memory associated with said processor. When the processor detects flow through the fluid supply system, the processor uses the flow criteria to characterize the detected flow. If such flow complies with predefined flow conditions, a flow event is noted and an alert is issue. Such alert is configured according to predefined alert-criteria stored in a memory.

Abstract: A flow indicator for showing blocking of filter cotton, being installed in a pipe line of a spraying head for the purpose of showing and controlling blocking of filter cotton in a filter in connecting with a submerged pump for the spraying head, it has a tri-branch tube to connect the pipe line, and to connect to a housing provided therein with an electric power source, an indicating device, an igniting switch and a triggering device, the tri-branch tube is provided therein with a pusher rod that can detect the pressure of water and can thus be moved. When the filter cotton is blocked to lower the water pressure, the pusher rod is moved and makes the triggering device to turn on the indicating lamp device, in order to warn a user to clean or change the filter cotton of the filter.

Abstract: Device for dissipation of gases created in the event of a quench of a superconducting magnet has a quench tube and a front sealing element closing the quench tube on the magnet side. The quench tube is sealed by a rear sealing element, and at least one sensor is associated with the tube segment closed by the sealing elements. The measurement values of the sensor represent a measure for the impermeability of the tube segment. The sensor communicates with an alarm emitter via which an alarm signal can be output upon detection of a leakage of the tube segment.

Abstract: A highly sensitive low loss and low flow fluid flow switch is coupled with an automatic timer and/or optional transmitter to indicate the flow of gas to an appliance and to automatically start a reminder timer to turn the appliance off. After a preset time limit has expired, the timer either sounds an alarm or wirelessly triggers an alarm in a remote location. The receiver portion of the wireless timer may be mounted directly to the appliance (grill handle), so that the timer automatically resets when activity (cover opening or closing) is detected, indicating the appliance is still in use. An alarm can also be configured to sound when the grill is attempted to be ignited with the cover closed, thereby avoiding a potential explosion. A biasing attraction magnet is incorporated in the fluid flow switch to offset either the force of gravity or a return spring in order to extend performance to low pressure and low flow applications.

Abstract: A pressure detector for detecting a high side pressure from a high pressure side impulse line and a low side pressure from a low pressure side impulse line includes a high side pressure variance calculating section for calculating a high side pressure variance from a high side pressure fluctuation calculated from a high side pressure signal, a low side pressure variance calculating section for calculating a low side pressure variance from a low side pressure fluctuation calculated from a low side pressure signal, a rate calculating section for calculating a variable according to a ratio of the high side pressure variance to the low side pressure variance, and a determining section for determining blockage of the high pressure side impulse line or blockage of the low pressure side impulse line based on a value of the variable.

Abstract: A water filtration system incorporating a fluid flow meter has a modular turbine casing assembly in which a turbine is located between upstream and downstream casing elements of identical shape and formed to be stacked so as to trap the turbine in between. The turbine is magnetized and rotation of the turbine is monitored electronically with a reed switch having a lead wire which is positioned proximate to the turbine to sense fluctuations in a magnetic field created by the turbine on rotation of the turbine. The reed switch housing itself is disposed at a location remote from the turbine. The system further includes processor for calculating an adjusted accumulated count data for low volumetric flow rates which are less than a predetermined threshold value. Advantageously, the invention can be used to reliably measure very low flow rates with very little power drawn.

Abstract: A controller controls a physical variable such as temperature of a controlled system. A variable calculator calculates and output a manipulated variable on the controlled system based on of a target value such as a target temperature and a feedback value such as the measured temperature of the controlled system. A dead-time compensator provides a dead-time compensated output using a model simulating the controlled system having a dead time and an idealized model having no dead time, based on the manipulated variable outputted from the variable calculator to carry out an ordinary control and a dead-time compensated control. A switch functions to select the dead-time compensated control by providing a dead-time compensated output to the variable calculator or an ordinary control providing no dead-time compensated output to the variable calculator. The dead-time compensated control is carried out at least during set point response of the controller.

Abstract: Apparatus 1 for detecting a change of flow rate of a fluid being pumped through a pipe 2, the apparatus 1 comprises a cylindrical chamber 4, a fluid sensor 6 disposed on the side of the chamber 4, alarm means 8 and a vent valve 10 located at a distal enclosed end of the chamber 4. The chamber 4 extends upwardly from the pipe 2 and is formed with a port 4 at the lowermost end of the chamber 4. The lower end of the chamber 4 is formed with a port 7 that extends through the wall of the pipe 2 such that the inner region of the chamber 4 is in fluid communication with the pipe 2 via the port 7. The fluid sensor 6 may be a solid state liquid level switch such as an optical liquid level switch. It will be appreciated that other types of fluid level sensors may be used. The fluid sensor 6 is in communication with the alarm means.

Abstract: A stall indicator for use on an aircraft comprises: a structure for mounting a housing at a leading edge of a wing of the aircraft; a paddle disposed to air flow at the leading edge of the wing and movable in response to the air flow; and a proximity sensor disposed at the housing for detecting movement of the paddle at a sensing area. Also disclosed is a method of indicating when an aircraft is approaching a stall condition comprising the steps of: permitting a paddle, disposed at a leading edge of a wing of the aircraft, movement with respect to a sensing area in response to air flow at the wing; detecting movement of the paddle by proximity sensing with electrical energy in the vicinity of the sensing area; and effecting an electrical signal representative of the detected movement of the paddle, which signal being indicative of an approaching stall condition at the wing.

Abstract: Apparatus for performing diagnostics through a regulator is disclosed. The pressure regulator is disposed in a fluid flow passage and has a throttling element moveable in the flow passage. A stem is attached to the throttling element. The apparatus includes a first pressure sensor for measuring pressure upstream of the throttling element, a second pressure sensor for measuring pressure downstream of the throttling element, and a travel sensor for detecting the position of the throttling element. A processor is provided which includes a stored algorithm for determining flow rate based on the measured pressure and travel values, and an alarm routine for generating logic alarms based on the measured operating parameters.

Abstract: A paddle type flow detector for an explosive environment is mountable onto a pipe. The detector includes a structure for mounting to a pipe, a substantially sealed switch housing containing an electrical switch, and a paddle located within the pipe. A lever mechanism connects to the paddle and extends up through the mounting structure and to the switch housing. A spring is contained between the switch housing and the mounting structure and is connected between the lever mechanism and a screw adjustable spring block. The spring is contained within a spring compartment formed between the switch conduit and the mounting structure. A slide rod is operatively connected to the lever mechanism and to the switch to change a state of the switch upon sliding movement of the slide rod. The slide rod is tightly fit within a bore of the switch housing and blocks a flame path between the switch housing and the spring compartment.

Abstract: A gas flow detector (10) includes a casing (12) with an inlet (14) for connection to a gas source and an outlet (16) for connection to a gas using appliance. Between the inlet and outlet there is an internal chamber (18) which receives a sleeve (24). Gas flow from the inlet (14) to the outlet (16) around the sleeve (24) is prevented by a seal (22) which encircles the sleeve (24). A piston (38) having a magnet (44) mounted at the lower end thereof moves in the sleeve (24) from a lower position (as illustrated) to an upper position. The piston (38) drops under gravity to its lower position when there is no gas flow. It lifts to its upper position as soon as there is gas flow. A magnetically operated switch (54) is provided below the position that the magnet (44) occupies when the piston (38) is in its lower position.

Abstract: A method and system for monitoring integrity of a filter (25) of a smoke or fire detector system. The system has a detector chamber (14) into which light is passed from a light source incorporated into a light source control circuit (10). Scattered light is detected by a light scatter detector (12). Controller circuit (16) receives signal from the detector (12) and makes a cumulative count over time of the number of dust particles detected.

Abstract: The invention includes a system for monitoring the performance of an automatic dosing siphon utilized in reservoir which is a part of a wastewater treatment system. The siphon includes a bell type cover, a fluid trap having one leg extending upward into the bell, and an outlet discharge pipe connected to said trap. A flow detect switch is located in the discharge pipe. Upon siphon activation the switch is opened and a countdown timer is reset. After draining the reservoir, the switch closes and the timer starts counting down a predetermined time period. If the siphon doesn't activate, time expires and an alarm is triggered. A second system utilizes a solenoid drain valve located above the outlet portion of the siphon trap such that upon time expiring the valve opens, the tank drains, and the timer resets. The valve automatically reprimes the siphon. The system continues to monitor the siphon and initiates an alarm upon subsequent siphon failures.

Abstract: An apparatus for detecting the flow direction of a fluid from an apparatus or between two apparatuses such as a biohoods, fume cabinets, or filters. The device includes a conduit horizontal plane and adapted to receive the fluid. A detecting element is disposed within the conduit and is movable in the direction of fluid flow, the detecting element being in direct contact with the fluid. A sensing element may be coupled to the conduit for determining when the detecting element reaches a predetermined position within the conduit. The circuitry coupled to the sensing element enables selection of a desired flow direction and actuates an alarm when the detected flow direction is other than the one selected.

Abstract: An apparatus for detecting the flow direction of a fluid from an apparatus or between two apparatuses such as a biohoods, fume cabinets, or filters. The device includes a conduit horizontal plane and adapted to receive the fluid. A detecting element is disposed within the conduit and is movable in the direction of fluid flow, the detecting element being in direct contact with the fluid. A sensing element may be coupled to the conduit for determining when the detecting element reaches a predetermined position within the conduit. The circuitry coupled to the sensing element enables selection of a desired flow direction and actuates an alarm when the detected flow direction is other than the one selected.

Abstract: A fluid drip detection system which is not prone to false alarms caused by the presence of dirt or solid particle contaminants in the fluid. The fluid drip detector comprises; a conducting hollow housing for permitting fluid flow and passage therethrough, the housing having a first and second conducting seats. A first conducting door is urged against the first seat and a second conducting door is urged against the second seat. The first and second doors disengage from their respective seats in a drip condition and in response to fluid movement. A conducting rod is connected to one of the doors and is slidingly fitted into a bore in the other door, such that in a no drip condition, if one of the doors is disengaged from its seat by dirt, the other door can still engage its seat, and a lead connected to the housing, for producing an electrical output in the event of a drip. Such electrical output is transmitted to a timer unit that can control the fluid flow by controlling a cut off valve.

Abstract: A pressure sensor assembly includes a disk entirely of metal and having a plurality of circumferentially spaced petals, separated by a plurality of radially extending slots. The slots extend from the periphery of the disk to a position near the center. However, the disks are in electrical communication with one another. A pair of wire leads are respectively placed at terminals on two separate spaced-apart disks with the opposite end portion of the leads connected to an alarm monitor. The disk body can be used in low or high temperature applications and is corrosion resistant and preferably entirely metallic (for example, stainless steel). The disk body is designed to be installed between standard pipe flanges, between a flange and a rupture disk holder, or in a holder that is used as, or located downstream of, a rupture disk or similar device. The device is designed to cause a discontinuity (open circuit) in an electrical circuit as a result of fluid flow through the pipe.

Abstract: A monitoring apparatus for monitoring the condition of a pressure relief rupture disk disposed in a pressure relief conduit is disclosed. The monitoring apparatus includes an electrically conductive rupture disk circuit, spaced apart electrodes affixed to the rupture disk, a rupture disk energizing circuit, a comparison circuit and an alarm circuit. The resistance between the electrodes changes when the disk ruptures. The energizing circuit includes a power source coupled to one of the electrodes. The magnitude of an output signal produced at the other of the two electrodes is dependent upon the resistance between the electrodes. The comparison circuit includes means for generating a selected magnitude output signal depending on the comparison of the magnitudes of the electrode output signal and an adjustable reference signal. The alarm circuit is electrically coupled to the comparison circuit and selectively activates an indicator alarm based on the magnitude of the comparison circuit output signal.

Abstract: An apparatus for detecting the flow direction of a fluid between two enclosed spaces, such as hospital rooms, includes a conduit extending along a horizontal plane and adapted to receive the fluid. A detecting element is disposed within the conduit and movable in the direction of fluid flow, the detecting element being in direct contact with the fluid. A sensing element may be coupled to the conduit for determining when the detecting element reaches a predetermined position within the conduit. The circuitry coupled to the sensing element enables selection of a desired flow direction and actuates an alarm when the detected flow direction is other than the one selected.

Abstract: An apparatus for detecting the flow direction of a fluid between two enclosed spaces, such as hospital rooms, includes a conduit extending along a horizontal plane and adapted to receive the fluid. A detecting element is disposed within the conduit and movable in the direction of fluid flow, the detecting element being in direct contact with the fluid. A sensing element is coupled to the conduit for determining when the detecting element reaches a predetermined position within the conduit. Circuitry coupled to the sensing element, enables selection of a desired flow direction and actuates an alarm when the detected flow direction is other than the one selected.

Abstract: A basic housing for a fluid flow monitoring assembly comprising a sensing leakproof elongate hollow body formed from a non-magnetic, metallic material and pivotally mounting internally of same a vane assembly that at one end includes a vane adapted to be inserted into a fluid flow of piping, with the vane assembly being spring biased to pivot oppositely of the direction of fluid flow, about its pivot mounting, for zero or reduced fluid flow conditions, and at its other end including a permanent magnet for electrically actuating a switch mechanism; such elongate sensing body defines an open end through which the vane projects and closed a end adjacent the magnet, which elongate body adjustably mounts crosswise thereof at its closed end within the permeability of the magnet for set point adjustment purposes a novel flow switch assembly comprising a plastic housing that is also leakproof and potably mounts in hermetically sealed relation a commercially available reed type off-on switch in electrical circuit arra

Abstract: A flow switch adapted to be attached to a pipe is designed to trip a switch at a preset flow rate. The switch employs a bending metal blade which deflects in the flow stream to move a magnet attached to the downstream side of the blade relative to a reed switch or Hall-effect switch. The switching device is preferably mounted in a slot on a printed circuit board to enable selection of a range of available trip points.

Abstract: An apparatus including a housing secured to a filter web, wherein the housing includes a reciprocating rod directed orthogonally through the housing relative to the filter web, whereupon plugging of the filter web permits the rod to be directed through the housing to effect actuation of a switch therewithin. The rod mounts a magnet to track a plurality of contacts of a switch within the housing to effect actuation of an audible and visual alarm.

Abstract: A flow sensor for detecting the absence of a minimum fluid flow in a sprinkler system. The fluid acts upon a vane positioned in the fluid path. Movement of the vane controls the position of a slider. The slider's surface has reflective and non-reflective ends which, in response to the vane's movement, reflect or absorb light from a light emission and detection means. The voltages from the light emission and detection means are monitored for indications of the fluid flow. The sensor uses a two wire signal transmitting system.

Abstract: A liquid flow switch apparatus is provided for connection to ducting wherein liquid flows forwardly. The apparatus comprises: a support body connectible to the ducting; a stem carried by the body to project into a liquid flow zone in the ducting, and a magnetically responsive switch in the stem; a cantilevered arm carried by the body to project into the flow zone upstream of the stem and to be deflected downstream into supported relation with the stem in response to flow impingement on the arm; and a magnet carried by the arm to be displaced by the stem deflection into sufficiently close proximity with the stem and the switch as to effect switch operation.

Abstract: A water-flow detector with an electronic time delay. There is a light-emitting diode and photo-transistor detector pair, a timer comprising an oscillator and a counter, and an alarm relay. The output of the photo-transistor is applied to the reset input of the counter, and the counter output is applied to the relay. The electronic assembly is positioned over the actutator arm of a paddle-type flow sensor assembly in such a way that movement of the arm by water-flow blocks the light path between the emitter and detector, which causes the photo-transistor output to go low, which releases the reset on the counter. The counter counts a predetermined time delay sufficient to avoid nuisance alarms due to temprary surges in the water conduit, and then activates the relay.

Abstract: A flow sensor for detecting the absence of a minimum fluid flow in a sprinkler system. The fluid acts upon a vane positioned in the fluid path. Movement of the vane controls the position of a slider. The slider's surface has reflective and nonreflective ends which, in response to the vane's movement reflect or absorb light from a light emission and detection means. The voltages from the light emission and detection means are monitored for indications of the fluid flow. The sensor uses a two wire signal transmitting system.

Abstract: A shower head volume meter producing an audible or other alarm for indicating when a predetermined volume of water has been delivered. A polite alarm or "beep" is used after a first volume of water y has been delivered, while an aggressive alarm in the form of a continuous sound is used after a second volume of water y+z has been delivered. A first embodiment measures the volume of water with a magnetic turbine and pick-up coil. The turbine rotates in response to water flow through meter generating a rotating magnetic flux. The flux lines cut across the pick-up coil which produces electrical pulse signals at a rate corresponding to the water flow rate. The number of magnetic poles in the turbine determines the total volume of water that can be delivered. A microcontroller analyzes the pulse signals and initiates the alarm. The pick-up coil doubles as an alternator to produce electrical power for the microcontroller.

Abstract: A flow sensor for regulating the air flow rate to a cooling system can be formed as a housing for channeling the flow through a retangular cavity and a one piece vane of bent metal strip which deflects and closes an electrical contact at a predetermined air flow rate and opens when the air flow rate falls below a preset threshold level.

Abstract: An apparatus for monitoring the flow of fluid in the pipeline has a hollow housing with a control element movably supported therein. The control element is movable under the action of the fluid flow, from an initial position to a position triggering a switching operation and is biased towards its initial position by a biasing system. A support ring is fixedly coupled to an inner wall of the hollow housing and has a central opening therein. The control element is composed of a connecting element which extends through the wall of the pipeline and through the central opening in the housing, which connecting element has a first end coupled to a magnet and a second end connected to a flow deflecting body. The connecting element is pivotably mounted to the support ring about an axle extending therethrough. A flow diverter or a seal assembly is utilized for preventing fluid flow from the pipeline from going around the connecting element and through the central opening into the housing interior.

Abstract: A plastic paddle is pivotally connected to the operating arm of a microswitch. The paddle is positioned in front of a boat's drain opening. The paddle can be swivelled to one side to allow removal of the boat's drain plug. When the plug is removed and the paddle lies in front of the drain opening, if the boat is launched without replacing the drain plug, the inrushing water will move the paddle so as to close the microswitch and actuate an alarm. Enough of the drain hole is left uncovered by the paddle to allow water to drain out of the boat.

Abstract: A flow meter or monitor arranged on a conduit section through which a medium to be monitored flows includes an actuating element extending through an opening in a wall of the conduit section, with a flow pressure plate of the actuating element positioned in the flow path of the medium. The actuating element is mounted on a support plate and is deflectable against the force of a spring with a deflectable outer end projecting into a housing positioned outwardly of the opening in the conduit section. The housing may be detached from the conduit section. The end of the actuating element projecting into the housing is equipped with a permanent magnet to operate a reed contact switch to be in an electrical circuit when the actuating element is deflected. The switch is surrounded by a protective cover and is accommodated in a through-hole in the housing. The support plate can be detached and inserted into a recess of the housing and is prevented from rotation with respect to the housing.

Abstract: A switch is responsive to fluid flow within a conduit. It is highly sensitive to variations in flow and forms an effective seal between the fluid and atmosphere. It includes a plastic pivot ball in a spherical seat. A blade extends from the pivot ball into the conduit where it can be displaced by fluid flow to rotate the ball. A lever is eccentrically connected to the pivot ball and extends upwardly within a closed, non-magnetic, housing. The upper end of the lever carries a magnet which actuates a switch outside the housing. An adjustable spring between the top of the lever and the housing permits adjustment of the sensitivity of the response.

Abstract: A water-flow detector with an electronic time delay. There is a light-emitting diode and photo-transistor detector pair, a timer comprising an oscillator and a counter, and an alarm relay. The output of the photo-transistor is applied to the reset input of the counter, and the counter output is applied to the relay. The electronic assembly is positioned over the actuator arm of a paddle-type flow sensor assembly in such a way that movement of the arm by water-flow blocks the light path between the emitter and detector, which causes the photo-transistor output to go low, which releases the reset on the counter. The counter counts a predetermined time delay sufficient to avoid nuisance alarms due to temporary surges in the water conduit, and then activates the relay.

Abstract: A cylindrical shuttle having a cone-shaped cam surface on one end which slides freely on a timer shaft between a first stop and a second stop which are attached to the shaft. A vane arm driven by a water vane engages the side of the first stop opposite the shuttle. In the normal (no-flow) condition, the vane return spring presses the vane arm against the first stop, which in turn forces the shuttle cam surface against the plungers of two microswitches on either side of the timer shaft, causing the plungers to ride up the cam surface to rest on the shuttle. When water flows, the vane arm releases the first stop and the timer shaft begins to move. After the shaft moves the free distance between the second stop and the shuttle, the second stop engages the shuttle and forces it out from under the plungers. When the plungers reach the cam surface, the shuttle cams out from under the plungers allowing them to release freely and rapidly.

Abstract: An airflow switch for sensing airflow or lack of same in an air duct comprising a housing base, mounting in side-by-side relation an adjustable range spring and a single-pole double-throw snap action microswitch, with the microswitch having its actuating lever operated by a bellcrank type input lever against an adjustable spring bias applied thereto by the range spring, with the housing base having an open center across which is secured a metallic disc that forms with the base an essentially isolated chamber in which the input lever is disposed, with sealing gasketing being applied to and about the disc rim, and with the disc being formed adjacent the mid portion thereof with a cross aperture through which the shank of a vane assembly extends for securement to the bellcrank input lever for operation of the vane assembly against the range spring bias; the vane assembly includes a vane adapted to be disposed well within the duct, and the vane assembly shank is dust sealed thereabout adjacent the disc through ap

Abstract: An air quantity regulating apparatus for air conditioning according to the present invention has two functions one of which is a constant air quantity function and the other is a variable air quantity function in cooperation with a room thermostat. When a constant air quantity control switch is turned on, the apparatus serves as the constant air quantity apparatus, on the other hand when the switch is turned off, the apparatus serves as the variable air quantity apparatus.

Abstract: A through-flow monitor of the type which produces a switching signal as soon as the rate of flow through a duct reaches a particular level consists of a generally tubular housing 1 which can be inserted via screw-threaded or other connections 3, 4 into the flow duct. Inside the housing 1 there is located a shallow diaphragm 5 which is biased by a coil spring 8 into a rest position against an abutment 9. The shallow diaphragm 5 is either of magnetic material or carries a magnetic element and is displaced in the downstream direction by the flow through the housing. A switch device such as a reed switch or Hall generator is located outside of the duct and is switched in as soon as the diaphragm moves to a predetermined position within the duct representative of a particular rate of flow therethrough.

Abstract: A self-contained fire protection system can be supplied in kit form and is specifically adapted for installation by a novice in prefabricated or site built housing, such as, a mobile home, travel trailer or like building structure. The system comprises an inlet delivery line which can be suspended beneath the floor of the mobile home and attached to a source of water under pressure with one or more risers extending upwardly from the delivery line through the floor into the interior of the mobile home, and upper branch lines containing automatic sprinkler heads are arranged in series in each branch line and can be attached directly to the risers and inlet line as well. The delivery line has a dual check valve and water flow indicator or switch, the latter being responsive to opening of any one or more of the sprinkler heads to activate a shunt trip breaker circuit so as to automatically interrupt electrical service to the home including the gas line into the home while activating an alarm circuit.

Abstract: Apparatus for controlling the rate of flow of a powdered solid material such as flour, comprising a load cell supporting an inclined plate onto which the flour particles impinge after falling through an inclined gate valve. The output of the load cell is fed to a control circuit including a direct proportional control section and an integrated error section with a monitor circuit sensitive to excessive integrated errors. The control circuit acts on an electric motor controlling the opening of the gate valve to maintain a predetermined rate of flow.