Abstract: A pressure sensitive sparkless switching device includes a layer of piezoresistive cellular polymer foam, at least two conductive layers, and an insulative spacer element having at least one opening. When pressure is applied to the device the piezoresistive foam disposes itself through the opening of the spacer element and makes electrical contact between the conductive layers. The resistance of the piezoresistive foam varies with the amount of pressure applied to provide an analog as well as on-off function. The device may also provide multiple switching, and shear detection capabilities.

Abstract: A liquid level alarm system which activates an alarm when liquid in a container falls below a predetermined level. The system contains an alarm which is located outside of the container. The alarm is electrically connected to an activation device which is contained within a housing. A single-pull switch arm is connected to the activation device and protrudes from the housing. One end of a line is attached to the distal end of the arm. The other end of the line is wound about a spring reel mounted on an axle connected to a float. When the surface of the liquid is between a predetermined upper and lower level, the spring reel maintains the line taut directly below the switch arm. The line is of such length that should the liquid in the container drop below a predetermined level, the float will no longer be supported by the liquid, and the weight of the float will pull the arm down to activate the alarm.

Abstract: A device is provided for protecting a heating element in an electric water heater which consists of a sensor for sensing a predetermined amount of water that has entered the electric water heater and an electric circuit with a relay controlled by the sensor, for energizing the heating element when the predetermined amount of water is within the electric water heater and covering the heating element thereby preventing the burn out of the heating element; wherein the sensor has a float with electrical contacts that engage adjustable contacts set at a desired level to energize the heating element at a predetermined water level and includes an expandable seal mounted on the float preventing water from going above the float.

Abstract: A conveyor dishwashing machine in which racks of dishes are conveyed from a loading surface through a hood which presents washing and rinsing zones and onto a discharge surface. In the washing zone, wash spray is applied to the dishes from a spray system which is easily removed for cleaning and easily replaced in the proper position. In the rinsing zone, a rinse curtain applies an initial rinse and creates a barrier against the wash spray. A final rinse of clean city water is applied subsequent to the rinse curtain. Automatic controls operate the machine with a minimum of human intervention.

Abstract: An apparatus for measuring a water level of a dam by combining a pressure type water level gauge measuring the water level by detecting water pressure at a bottom of the dam, with a plurality of float type water level switches arranged along the depth of the dam and provided at an interval less than a tolerance allowed to the gauge. Obtaining a water level difference between the water level measured by the gauge and the water level at the switch respectively, the gauge water level is corrected to a water level obtained by subtracting the difference at one of the switches from the gauge water level, when a water surface of the dam is located between the one of the switches and the gauge or an adjacent switch. The abnormality of the gauge is found by detecting whether the difference exceeds a water level tolerance allowed to the gauge.

Abstract: An apparatus for providing a signal to indicate liquid level above a pre-determined level in a container. The apparatus includes a device for defining a fixed reference level. An alarm unit having an alarm and an alarm actuator is connected to the defining device. A float is connected to the alarm unit and rests on the surface of the liquid. The float actuates the alarm actuator to activate the alarm when the surface of the liquid reaches the pre-determined level.

Abstract: A liquid level sensing device utilizing a conductive hollow sphere buoyed by the liquid and guided vertically within a metal tube. An elongated resistance card is mounted in the tube adjacent the sphere to permit the sphere to slide along its surface as the liquid level changes thereby electrically connecting a portion of the resistance card to the metal housing through the conductive sphere. The resistance card is mounted so as to be flexed from its normal flat configuration with the flexed configuration producing a light force on the sphere to maintain good electrical contact therewith and between the sphere and the housing but insufficient to deter the sphere from following liquid level changes.

Abstract: In a liquid level detecting device for fuel or oil in a small size boat, a liquid level detecting switch turned on and off in accordance with a vertical movement of a float provided in a tank and a liquid level warning device are connected in series to a power supply circuit from a generator of an engine.

Abstract: A level indicating device for liquid filled containers is provided having a floating sensing element which is operatively connected with a signal device, the sensing element having several, preferably three floats arranged on a single plane. The floats are supported on lever arms which are interconnected with each other at a central union. The lever arm union is supported for free movement in a guide disposed approximately in the center of the container and approximately vertically aligned with the surface of the liquid when the liquid is at rest. The longitudinal movement of the lever arm union in the guide caused by changing liquid levels is transmitted to a signal device for monitoring the liquid level.

Abstract: A visually and mechanically testable float switch composite is presented. The composite had a casing having one opening into a switch cavity containing a switch having leads potted to the outside. A float is coupled through the opening by coupling means to mechanically actuate the switch. The opening is closed by a bearing and bearing cap surrounded by and sealed by an elastomeric boot. Closing of the cap increases pressure on the fluid in the switch cavity thereby causing the boot to expand like a balloon thereby permitting visual or mechanical testing since the boot remains expanded if there is no leak. In like manner, any submersible component may be made visually and mechanically testable by inserting a cap thereby increasing the internal pressure and monitoring a balloon like expandable boot to determine whether the increase in pressure is maintained.

Abstract: A hydraulic fluid reservoir for automobile including a partition wall within a reservoir casing defining a float chamber and extending from the bottom of the reservoir casing, a float which is movable in said float chamber so as to cause a switch to close or open at a predetermined float level, a communication opening communicating the float chamber with the outside chamber of the partition wall at the lower portion thereof and a fluid reflection cover disposed on the float chamber, malfunction of the level detector is avoided.

Abstract: A device for indicating the flow of gases includes a vertically extending conduit section in which is disposed a ball. The ball seats on a lower seat at zero or minimum gas flow, and on an upper seat at maximum sensed gas flow. The upper seat is configured to permit essentially unrestricted gas flow when the ball is seated on it.Electrical means are associated with either the bottom seat and/or the top seat and co-acts with the ball to sense either minimum gas flow or maximum gas flow, and generate a signal responsive thereto.

Abstract: A bilge pump switch apparatus for activating and deactivating the bilge pump of the vessel in response to predetermined water levels in the bilge area comprising a housing defining a chamber therein and provided with a fluid port for receiving and discharging bilge water, a mercury tilt switch suspended within the chamber and being responsive to tilting for opening and closing a circuit including a battery, the mercury tilt switch and the bilge pump, and a float responsive to the water level in the chamber for positioning the mercury tilt switch in its normally open position and its normally closed position.

Abstract: A protection column is employed about a sump pump to exclude liquid and foreign matter in the sump from entering the pump interior until a time just prior to priming and activation of the pump. The column has a closed bottom portion serving as a vessel and permitting the column to float as the liquid level rises in the sump. The upper part of the column fits about the pump to act as a guide and has a series of vertical slots. The column floats until the bottom of the column strikes the bottom of the sump pump, which prevents the column from rising further. As the water level continues to rise in the sump, water enters the column through the slots, causing the column to sink to the bottom of the sump and permitting the liquid to rise to a level in the pump commensurate with the level elsewhere in the sump, thereby priming the pump.

Abstract: A liquid level responsive proximity switch for submersible sump and sewage pumps in which a magnetic float, normally buoyed on mercury or other conductive liquid, is submerged by a movable magnetic actuator to displace the mercury into contact with a pair of switch electrodes. The mercury, magnetic float and electrode assembly are housed in permanently sealed casing having a downwardly opened chamber for the actuator under the magnetic float.

Abstract: This invention relates to an improved method and apparatus for detecting the level of a first fluid. It includes a reservoir within the first fluid, the reservoir being bounded by a flexible membrane at its lower portion for containing a second fluid. The reservoir contains at least one switching means biased to assume a first position when the second fluid is below a predetermined level and adapted to assume a second position upon the rising of the first fluid into pressure exerting contact with the flexible membrane. The rising first fluid compresses the lower flexible membrane portion of the reservoir and causes the second fluid within the reservoir to also rise thereby causing the switching means to assume the second position.

Abstract: A float type circuit breaker for controlling a valve in a pool which includes a housing having an inlet which permits entry and exit of water as the height of the water changes in the swimming pool. A porous baffle prevents surges of water from entering the pool. A pivoted float within the chamber has a mercury switch mounted therein and arranged to complete the circuit to actuate the swimming pool valve when the water has drained from the chamber permitting the float to pivot downwardly therein. A skirt is provided on the housing to permit a motor driven pool sweep to pass thereover.

Abstract: A hydraulic brake fluid level sensing system having a switch housing above a diaphragm which sealingly encloses a fluid reservoir. A float rod guide extends through the diaphragm and a float rod extends through the rod guide and into the switch housing. A float vertically positions the float rod in accordance with brake fluid level. A switch element is positioned by the float rod to bridge a pair of contacts when the fluid level decreases to a specified level. A slot is provided in the rod guide to provide a vent to the fluid reservoir when the diaphragm is moved down the rod guide by differential pressure thereacross resulting from brake fluid loss.

Abstract: Liquid SF.sub.6 from the high pressure storage tanks within the gas sealed enclosure of a multi-interrupter gas insulated circuit breaker is collected in a tank located externally of the circuit breaker enclosure. A float within the liquid collecting tank operates a micro switch to effect operation of a solenoid actuated valve to pass the liquid SF.sub.6 into the low pressure system of the circuit breaker wherein it again returns to its gaseous state. The collected SF.sub.6 gas in the low pressure system is pumped back into the high pressure system through a compressor.

Abstract: A switch means for closing an electrical circuit to operate any desired device such as a pump or an alarm, the switch means being adapted to be positioned in the bilge of a ship or boat and being actuated into circuit closing position by the rising of the bilge water beyond a predetermined level, the switch means including a float riding on the water and wires which are always clear of the water and are not subject to bending or frictional stresses and strains.