Abstract: A double loop heat storage space heating furnace has a housing with an upper heat storage section containing an electrically heated heat storage brick portion and a lower section containing an air-to-air heat exchanger having first and second air flow passages. The furnace has two separate flow courses. The first flow course uses a room air fan to circulate room air through the first passages of the heat exchanger. The second flow course has a recirculating fan in the lower housing section for recirculating air in a continuous closed loop through the heat storage brick portion to be heated and the second flow passages of the heat exchanger so that heat is delivered from the heated recirculated air and the room air in the heat exchanger. The upper housing section includes a cooling air space surrounding the heat storage brick portion through which the room air fan circulates a portion of the room air to maintain the furnace housing at a temperature similar to that of the room air.

Abstract: An electric forced air heating device using PTC elements for heating and having a fixed volume of airflow established by a blower driven at a constant rate. A pair of parallel air paths are established in the device, with one air path having the PTC elements fixedly located therein. A laterally movable damper is used to control airflow through the two air paths, and is positioned proximate the PTC elements a fixed distance therefrom so that as the damper is shifted, airflow proportionally increases through one of the air paths and proportionally decreases through the other air path to control the heat output of the PTC elements. The energization of the PTC elements and blower is controlled by a switch activated by movement of the damper.

Abstract: A heating set having a plurality of positive temperature coefficient thermistor heating elements (PTCR pieces) sandwiched between two heat radiating devices made of metal with each of the PTCR pieces provided with sprayed-on electrodes having their exposed surfaces making close contact with long metal battens on the outer surfaces of the heat radiating devices through conducting thin metal pieces having predetermined surface areas. The PCTR pieces and the heat radiating devices making electrical contact through the thin metal pieces are bonded together by an electrically nonconductive adhesive spread on the border of the battens around the thin metal plate and on opposite parallel edges on the border of the sprayed-on electrodes of the PTCR pieces.

Abstract: An improved carpet dryer is disclosed for drying carpets saturated with water. The dryer includes a securing mechanism for maintaining the edge of a carpet on the upper surface of the air outlet portion of the device. The device further incorporates a shroud disposed on one air intake of the dryer to minimize the effects of air turbulence within the dryer unit.

Abstract: An apparatus for heating the inner cylindrical wall of a device, such as a bearing, gear, sprocket, coupling, sleeve, or the like, for expanding the cylindrical wall to facilitate the installation of the device on a receiving element includes a source of heated air coupled to an elongated cylindrical air distributor having an outer diameter small than the inner diameter of the cylindrical wall. Adjustable supports position and align the air distributor and the device to allow distributor to be inserted into the device with their central axes substantially coaxially aligned so that an annular space is created therebetween into which heated air is communicated from the distributor through a plurality of opening on the distributor. Annular baffles on the distributor close the opposite sides of the annular space while allowing exhaust of sufficient heated air to prevent undesired pressure buildup in the space.

Abstract: An air conditioner has a refrigeration system with a compressor, a motor for air-circulating fans, indoor and outdoor heat exchangers and a four-way valve connected through refrigerant conduits such that it can be operated selectably both for cooling and for heating. An electric heater is also provided for heating. An electrical circuit for the air conditioner has a series connection of (1) a first temperature switch which opens when the temperature of the motor becomes too high, (2) a thermostat of an ordinary kind which places its connector piece in an open or closed position by comparing room temperature with a user-set temperature level, (3) a relay which controls the switching of the compressor of the air conditioner on and off, and (4) a second temperature switch which opens when the temperature of the electric heater becomes too high.

Abstract: A forced gas electric heater has a serpentine heating element in series with a preheat coil. Gas to be heated first flows through the preheat coil before flowing through the serpentine heating element. A thermistor is disposed between two adjacent turns of the preheat coil. The thermistor controls the "on" time of a solid state power control device which is in series with the preheat coil and the serpentine heating element.

Abstract: An apparatus for the oxidation of particles suspended in the air with a refractory material block (4) provided with small volume ducts (5) inside which s resistive wire is passed in order to generate a higher power density. The maximum volume of the ducts (5) is 10.sup.3 m.sup.3 and its maximum cross section area is 1 cm.sup.2, the ducts being dimensioned in such a way that the minimum permanence time of the air mass in their interior is 1 second and the minimum power density is equal 50 KW/m.sup.3. The block (4) may be disposed inside a metal box (7) which also contains a fan, the motor (11) of which is commanded by an electronic control circuit (10) that receives signals related to the block temperature by a thermal sensor (9) disposed within the block.

Abstract: A clamshell housing encloses a nail dryer. The housing includes a cover pivotally connected to a base. The cover may be opened by applying leverage to it and exposing a nail drying zone. The cover may be pivotally closed to form a compact package when not in use. A nail drying fan is actuated when the cover is opened thus closing an electrical circuit. The electrical connection is interrupted when the cover is tipped into a closed position.

Abstract: An air heater with a safety control circuit is disclosed. A heat source is mounted within a hollow housing having an air inlet end and an air outlet end. The heat source is actuated in response to the presence of a heat control signal. The heat control signal is produced when both a predetermined minimum pressure differential between static air pressure outside the hollow housing and the air velocity pressure within the housing is reached and the temperature of a portion of the housing is lower than a predetermined maximum sensed temperature. Application of the heat control signal to the heat source can be manually initiated or interrupted.

Abstract: A soldering apparatus of a reflow type contains a preheating chamber and a reflow chamber which are provided with a plurality of heaters for heating printed circuit boards with chips temporarily mounted thereon with solder pastes during conveyance by a conveyor. The heaters are mounted on the side walls of the chamber, extending along a direction of conveyance of the printed circuit boards. The chambers are also provided with a screening member respectively so as to prevent direct radiation of radiant heat from the heaters into the chambers and onto the printed circuit boards and to provide a uniform air flow so as to be blown uniformly onto the printed circuit boards.

Abstract: An improved radiator suitable for use with internal combustion engines in motor vehicles is provided. The invention converts conventional radiators, which ordinarilly provide heat to passenger compartments through exchange of heat built up in the coolant, into electrically operable radiators with electric resistance heating elements, commonly PTC resistors. The PTC resistors have self, temperature-regulating properties which prevent over heating. Additionally, sheet metal strips in heat-transmitting contact with the PTC resistors and spring elements acting on the sheet metal strips provide an efficient heat transfer mechanism whereby heat from the resistors is transferred without the self-regulating resistors constantly shutting off.

Abstract: An electric thermal storage heating unit including (i) an insulated housing defining a storage chamber with two laterally extending linear openings through the base of the storage chamber, (ii) a plurality of heat-sink bricks within the storage chamber which define separate vertical ducts above each of the lateral linear openings, and (iii) a pair of substantially planar, serpentine electrical heating elements each defining an uppermost portion with parallel upper right and upper left sides and a lowermost portion with parallel lower right and lower left sides wherein the uppermost portion is angled with respect to the lowermost portion within the plane defined by the element so as to cause the right and left sides of the lowermost portion to extend at an obtuse angle of less than 180.degree.

Abstract: The invention relates to a method of manufacturing a heating element from a flat metal foil blank in which strips (1) are formed whose ends (2) are interconnected by connecting portions (3, 4) with alternate connecting portions disposed at opposite ends of the strips so as to form a meandering pattern and to a heating appliance incorporating such a heating element. In order to make such a foil heating element suitable for use in appliances in which an air stream to be heated passes over the foil heating element the connecting portions (3, 4) are bent in such a way that the strips (1) are tilted out of the plane of the foil blank. Preferably the strips are disposed an an angle .alpha. between 45.degree. and 90.degree. relative to the plane.