Abstract: A wet-niche type lamp for providing underwater illumination in a swimming pool or the like includes an over-temperature protection circuit which interrupts the supply of electrical energy to the lamp when the level of the cooling water surrounding the lamp drops below a predetermined level. The circuit includes thermistor mounted in an heat exchange relationship with the surrounding water so that heat energy generated in the thermistor, as a consequence of the current flow through it, is normally transferred to the surrounding water. Should the level of the surrounding water drop below that of the thermistor, the thermistor heat energy quickly evaporates any remaining water film on the exterior surface of the thermistor to allow its temperature to rise. The control circuit, in response to the temperature increase, interrupts the flow of electrical energy to the lamp to prevent over-temperature operation.

Abstract: A connector for terminating the end of a sheathed heating element is formed by an elongated body having a cavity at one end. The cavity includes at least one surface having a diameter dimension adapted to slidingly engage one of the diameter surfaces of the heating element sheath, and a thrubore, concentrically located with respect to the cavity diameter, adapted to slidingly engage the terminal pin of the heating element. The connector will mate with a heating element if and only if the heating element terminal pin is properly located with respect to the heating element sheath.

Abstract: A dual source heat pump system is disclosed for automatically selecting in either the heating or cooling mode of operation that source which will most efficiently meet the heating or cooling demand required of the system. The heat pump system includes valves located so that the heat exchanger associated with the source not selected can be isolated from the remainder of the system and temporary pumping cycles initiated at the conclusion of a heating or cooling cycle for pumping all the refrigerant into the indoor space exchanger coil. Virtually all the refrigerant charge is thereby maintained in the active portions of the heat pump system while the inactive portion is completely isolated.

Abstract: A combined environmental and refrigeration system for use in a supermarket or the like includes a plurality of environmental and refrigeration modules and controllable air flow dampers to provide selected air flow modes to a conditioned space. Each module includes a hot deck compartment having a fan and the condenser portion of a refrigeration system to heat an air flow through the hot deck compartment, and a cold deck compartment having the evaporator portion of an air conditioning system to cool the air supplied to the conditioned space. At least a portion of the condenser in one of the hot deck compartments is provided to sub-cool the refrigeration system working fluid.The various fans, evaporators, condensers, and dampers are controlled by suitable control means to provide a conditioned space dehumidification mode, and a plurality of conditioned space cooling and heating modes.

Abstract: A liquid dispensing and vapor recovery system in which an underground storage tank applies gasoline to a dispenser located at a filling station or the like for dispensing the gasoline to a vehicle gasoline tank, under the force of a pump located in the storage tank. A vapor return line is provided for passing vapors in the vehicle tank through the dispenser and back to the storage tank. A valve assembly is utilized to permit the flow of vapor from the vehicle tank to the storage tank and to prevent the flow of vapor from the storage tank to the vehicle tank in the absence of a predetermined relatively high pressure.

Abstract: A method and apparatus for initiating the defrost of refrigeration equipment on demand. A defrost clock which normally controls the conventional refrigeration and defrost modes of a refrigeration system includes an auxiliary switch to cease operation of the clock motor a predetermined time prior to normal defrost initiation. The defrost clock thus remains in the refrigeration mode until the demand defrost sensor switch, or an optional demand switch, initiates a defrost cycle of the refrigeration equipment. The closure of the demand defrost switch or the optional switches causes the defrost clock motor to run for a predetermined short period of time. The defrost clock switch subsequently closes slightly prior to initiation of a defrost to guarantee that the clock runs throughout the defrost mode. Thereafter, the defrost clock controls the length of the defrost and will terminate defrost upon a signal from a thermostat, or by a time signal, or a pressure signal.

Abstract: A platform for supporting a motor-pump combination is molded as a unitary structure and includes a primary support and a detachable secondary support. The primary support includes a supporting surface formed at a first radius, and the secondary support includes a supporting surface formed at a second radius and a cavity adapted to receive the primary support. The platform, which retains the cost advantages attendant to one-step molded structures, may be readily converted from a platform for supporting a motor having a first radius to a platform for supporting a motor having a second radius by detaching the secondary support from the platform and mounting it over the primary support.

Abstract: A filtering system in which a plurality of filter assemblies are supported in a spaced relation relative to a common header which communicates with each of the assemblies. Each filter assembly consists of a plurality of individual filter units each of which is formed by a perforated tube and a filter material extending around the tube. The fluid to be filtered is drawn through the filter units and the header for passage externally of the system.

Abstract: An apparatus for dispensing fluid into a container in which a first passage is formed in a housing for permitting direct flow of fluid from an inlet to an outlet associated with the housing and a second passage receives a portion of the fluid and includes an eductor for creating a vacuum in the housing. A valve member is disposed in the housing and is normally biased into a closed position to close the passage. A manually operable lever is adapted to open the valve member and is controlled by a linkage mechanism responsive to the vacuum. A diaphragm seal is associated with the valve member for preventing leakage of fluid through the valve mechanism.

Abstract: A test plug assembly for insertion into a housing for preventing liquid under pressure from flowing therethrough includes an assembly body with an undersurface shaped and dimensioned to mate with a shaped upper portion of the housing. A plurality of flanges which project from the outer surface of the body are located and spaced apart so that the studs can pass between the flanges when the body is inserted into the housing and so that the uppermost surface of the flanges will engage the lowermost surface of the studs when the shaped upper portion and undersurface are in contact and the body is rotated relative to the housing. The body further includes a gripper for gripping the body so it can be rotated into engagement with the housing.

Abstract: In a lighting fixture, glare-free uniform illumination is achieved by means of a plurality of nested generally frusto-conical reflectors surrounding the light source of the fixture. The reflectors are shaped and positioned relative to one another and to the light source to concentrate light in the range of 65 to 71 degrees from downward vertical and to cause the intensity of the light to progressively decrease as the angle from downward vertical decreases from 65 degrees toward zero. The projected light from the fixture is concentrated in the 65 to 71 degree range from downward vertical in part by light radiated from the source at near horizontal and higher angles being doubly reflected between the frusto-conical reflectors and then projected in the high angle range. The reflectors are positioned relative to one another, to the light source and to baffles, to cut off any light from being projected at an angle from downward vertical greater than 75 degrees.

Abstract: A liquid distributor valve assembly in which an impeller means is disposed in a housing and is rotatable in the housing by the force of liquid entering the housing. A valve assembly is adapted to rotate in the housing in a manner to selectively control the flow of fluid through a plurality of outlets, and a gear arrangement selectively rotates the valve means in response to rotation of the impeller means.

Abstract: A method and apparatus for detecting blockages in one or more vapor flow lines such as vapor recovery lines used in liquid gasoline dispensing systems. The method and apparatus operate by sensing pressure in vapor flow lines and determining whether the frequency of the variations in the filtered rate of change with time of the pressure signal exceeds a preset limit indicating vapor bubbling through a liquid blockage. The method and apparatus also operate to determine whether the pressure signal exceeds a preset limit indicating a blockage condition.