Abstract: A liquid or gel filled pillow utilized for therapeutic purposes is formed from a pair of flexible casing of plastic or the like, one within the other, and being separated by a compressible electrically conductive foam material having a high resistance in its uncompressed slate and a low resistance when compressed. The facing surfaces of the casings are coated with a layer of highly conductive material in electrical contact with the foam. The inner casing is provided with a thermostatically controlled heating element for heating the liquid or gel contained therein. One terminal of the heating element is connected to the power supply through the conductive layers foam so that upon compression of the foam, as would be occasioned by a patient laying his head upon the pillow, there will result an electric current flow to the heating element due to the lowered electrical resistance of the foam.

Abstract: A power control device for controlling power to a resistance heater in an oven uses a microprocessor, temperature measuring circuit, power measuring circuit, a triac circuit for firing the heater, a power phase synchronizer whereby the microprocessor synchronizes A.C. current signal and allows the triac to fire for a calculated portion of each phase of A.C. current to provide power to the heater such that the oven temperature is accurately controlled. A cooling device for cooling to subambient temperature such as -150.degree. C. also is provided. The power control device and oven are used in conjunction with instruments such as a dynamic mechanical analyzer so that physical data on test samples can be obtained over a wide temperature range.

Abstract: An electric heater structure designed to be used as an auxiliary water heater for showers, sinks and the like includes a housing defining a water heating chamber having an inlet for connection to a water supply pipe and an outlet for discharging heated water through an attached sprayhead. A pair of electric resistance heating coils of different length and thus different heat output are positioned within the chamber for heating the water. A selector switch manually operated by a lever is provided in a switch casing mounted on the housing and is arranged to energize one or the other of the heating coils to produce either hot or warm water. A set of diaphragm actuated contact elements cooperate with the selector switch to allow energization of the heating coils only if water is flowing through the chamber from the inlet to the outlet thereof.

Abstract: Heated clothing includes:(a) multiple clothing sections adapted to cover different portions of the human body,(b) electrical wires carried by such sections and including bus wires and heater wires, and(c) circuitry for controlling battery powered electrical current flow to such wires, and including switch structure connected in series with one or more of the heater wires for interrupting current flow thereto without requiring disconnection of bus wires.

Abstract: An energy saving control circuit for a water heater having a hot water storage tank provided with an electrically operated heater, i.e., an electric heater or an electrically controlled combustion burner, includes a water flow detection device associated with either the cold water inlet or hot water outlet of the tank for sensing the flow of water into or out of the tank and arranged to energize the heater upon detection of water flow indicative of the withdrawal of water from the tank. A holding circuit maintains the heater energized, even though the flow of water ceases, until such time as a thermostatic switch responsive to the temperature of the water in the tank disables the holding circuit and deenergizes the heater upon the water stored in the tank attaining a predetermined desired temperature.

Abstract: An electric boiler includes a conductivity control having a controller responsive to both steam pressure and electrode current. The controller is operative to open a boiler feed water discharge valve when either the steam pressure or electrode current falls below predetermined values to discharge water from the boiler for a predetermined time interval after which the controller closes the discharge valve and opens a feed water valve to initiate the delivery of feed water to the boiler chamber. When the pressure or current sensor senses the elevation of steam pressure or electrode current to second preselected levels the controller closes the feed water valve. In addition, if the sensors determine that the steam pressure or electrode current have risen to third preselective levels, a transfer valve is opened to transfer boiler water to a storage tank until the pressure or current level falls to fourth preselected levels.

Abstract: A control system and method for an apparatus to glow discharge treat (such as ion nitride) a workpiece. The apparatus includes a housing to receive a workpiece and a low pressure atmosphere of ionizable gas (nitrogen and hydrogen for nitriding), and connectors for establishing a glow discharge in the gas with the workpiece connected as the cathode. The control system and method automatically control the apparatus throughout the process, utilizing operator selected parameters (such as warm-up time, processing time, workpiece operating temperature and chamber pressure). The control system divides the selected operating temperature by the selected warm-up time to provide a straight line increase per unit time of the workpiece temperature. Initially the control system accumulates the increases at a rate higher than the straight line increase and then, as the workpiece approaches the selected operating temperature, the control system accumulates the increases at a rate less than the straight line increase.

Abstract: An apparatus for pre-heating resin tablets comprising a resin tablet heater, a switch for setting a reference softening degree and a softening degree detector for the resin tablet. The detector includes a pressure source and a pressure transmitting member coupled to the pressure source and adapted for contact with the resin tablet. The pressure transmitting member is movable a distance representative of the softening degree of the resin tablet being heated due to deformation of the resin tablet.

Abstract: An energy saver control system for prevention of water freezing in an outdoor tank, such as a stock tank, which involves a conventional type of water level control valve to maintain a selected level of water in the tank, and an electrical switch which is controlled by the pressure which is in the water line leading to the water level control valve. Means are provided to control the rate of water flow into the tank to a selected low value, sufficient for prevention of freezing of the surface of the water in the tank. When water is flowing into the tank the electrical heater is cut off. The electrical switch is controlled by the pressure in the water line leading to the water level control means.

Abstract: A flow-activated water heater includes a body defining water inlet chamber communicating with a heating chamber containing an electric resistance heater through an intermediate flow duct. A movable piston supported by a flexible membrane and provided with a small flow-restricting opening separates the inlet chamber from the duct. A pair of fixed contacts disposed exteriorly of one side of the body are connected to the heater and a pair of movable contacts defined by substantially semi-circular conductive plates fixedly secured at one end relative to said body exteriorly encircle the flow duct with the other end thereof movable into and out of engagement with the fixed contacts. The other ends are also joined to an external carrier movable in the longitudinal direction of the duct. A pivotable lever mechanism exterds through the wall of the body and has its inner end connected to the membrane and its outer end connected to the carrier.

Abstract: A system for automatically purging heating mantles and other apparatus including an enclosed volume capable of low level pressurization. The system comprises a pressure sensor for sensing the fluid pressure within the enclosure, which may be the space between a heating mantle poncho and the enclosed flask, and a fluidic logic circuit which is responsive to a low pressure condition within the enclosure to deactivate the heating element in the mantle. At the same time, the logic circuit causes a predetermined volume of purging gas to flow through the enclosure and, after this has been accomplished, reactivates the heating element and reestablishes the minimum pressure conditions by flowing a small volume of purging gas into the enclosure. The system is particularly intended for use in hazardous locations where explosion-proof electrical equipment enclosures are normally mandatory.

Abstract: Under full flow conditions circulated water is conducted for heating through an elongated vertical chamber by a pump along a down-flow path from an upper lateral inlet to a lower outlet and in surrounding relationship to a vertically disposed electrical heating element in the chamber. The chamber is defined by a housing dimensioned to conduct flow with substantially no storage of water therein in order to progressively elevate the water temperature as the water is circulated through the chamber. The heating element extends upwardly from the lower axial end of the housing and terminates substantially at the level of the bottom of the inlet. Operation of the heating element is controlled by a thermostat and a flow responsive control both mounted on the upper axial end of the housing so that the heating element is energized only during periods of flow at a predetermined flow rate when the liquid is below a predetermined temperature.

Abstract: A continuous processor for exposed webs of photographic paper has several tanks and a system of hoses which connect the outlets in the lower portions with the inlets in the upper portions of the tanks. The liquid developer is circulated by a pump and is heated by a heater before it reaches the inlets. The pressure of liquid in the system of hoses is monitored by two pressure responsive switches which cause a control unit to arrest the motor of the pump and to deactivate the heater when the pressure drops below or rises above a range of acceptable pressures. The pressure drops in response to leakage of developer, and the pressure rises in response to clogging of a filter which is installed in the system of hoses between the heater and the inlets of the tanks.

Abstract: A system for automatically purging heating mantles and other apparatus including an enclosed volume capable of low level pressurization. The system comprises a pressure sensor for sensing the fluid pressure within the enclosure, which may be the space between a heating mantle poncho and the enclosed flask, and a fluidic logic circuit which is responsive to a low pressure condition within the enclosure to deactivate the heating element in the mantle. At the same time, the logic circuit causes a predetermined volume of purging gas to flow through the enclosure and, after this has been accomplished, reactivates the heating element and reestablishes the minimum pressure conditions by flowing a small volume of purging gas into the enclosure. The system is particularly intended for use in hazardous locations where explosion-proof electrical equipment enclosures are normally mandatory.

Abstract: A steam heated cooking pan comprises in combination a double-mantled food preparation vessel arranged above a steam generator which includes an outer vessel and an open bottom inner vessel enclosed in the outer vessel and in which are disposed steam generating electrodes. A steam exhaust opening is provided at the upper end of the inner vessel for supplying steam to the double-mantled vessel. Steam generation is automatically controlled by a movable cover opening and closing the steam exhaust opening in response to steam pressure sensed by a pressure sensitive member arranged below the outer vessel and coupled to the cover by an actuating rod passing through a tube secured to the bottom of the outer vessel and extending upwardly to the opening. The tube communicates the pressure sensitive member with the inner vessel and prevents contact between the water in the steam generator and the pressure sensitive member and actuating rod thereby preventing deposition of time thereon.

Abstract: An electronic circuit for sensing and controlling the pressure and temperature of ink within an ink jet print head. Ink pressure is monitored by a pair of strain gauges electrically connected into a bridge whose output controls an ink supply valve. Part of that bridge is utilized with additional elements to form a second bridge for monitoring through one of the strain gauges the temperature of the ink jet head, accompanied with a heater of the head that is driven from the temperature signal to maintain the head temperature above a preset temperature.

Abstract: A liquid flow activated switch is operative to effect completion of an electrical circuit and energizing of an electrical power using device, such as an electric water heater, upon commencing of liquid flow through a liquid inlet of a housing having walls defining a chamber therein. A switch member is pivotally mounted in the chamber and has a first portion positioned between the liquid inlet and a liquid outlet so that liquid entering the chamber impinges upon the first portion of the switch member to move a second portion of the switch member and a magnet thereon to a second position energizing magnetically operated components mounted on the housing and electrically connected to the electrical circuit.