Abstract: A snow and ice melt system for a roof may feature heat plates which protect and contact heat cable to distribute heat over a wider area than cable alone. Bends in the plates create attachment structures by which the plates are assembled and by which heat cable is contained.

Abstract: A medium-voltage heating element assembly. The medium-voltage heating element assembly can include a dual core having an inner core and an outer core. Segments comprising the inner core and the outer core can be staggered. Furthermore, the dual core can include a notch-and-groove interface to prevent axial rotation of the inner core and/or inner core segments relative to the outer core and/or outer core segments. A bushing of the heating element assembly can include a stepped region, and the bushing can interface with the dual core along the stepped region.

Abstract: A high voltage resistor includes a ceramic substrate having a surface and defining a groove, and a resistive film deposited in the groove such that the resistive film is recessed relative to the surface of the ceramic substrate.

Abstract: Disclosed herein is a porous ceramic heating element wherein 0.08 to 1.00 wt % of a foaming agent is added in 99.00 to 99.92 wt % of a mixture of an inorganic material, a binder, a conductive material, a hardener, a bonding agent and a dispersion medium and mixed with the mixture. The bonding strength of porous foam formed in the ceramic heating element is increased, thereby providing an effect that the entire structure is hardened.

Abstract: A heating apparatus for an enclosure including at least a ceiling and a side wall, the apparatus includes a plurality of electrical resistance heating wires or sections of electrical resistance heating wire, and support means therefor. The support means include support members each having a first part adapted to be secured relative to the ceiling or side wall and a second part which projects inwardly of the enclosure, the second part including a plurality of spaced apart heating wire support formations. The support members and the heating wire support formations are arranged such that in use substantial portions of the length of each of the plurality of the heating wires or sections of heating wire, are supported side by side by the support members each parallel to or generally parallel to each other and to the ceiling or side wall of the enclosure.

Abstract: A resistor constituted by a spiral region (4) of a second conductivity type and having a determined doping level, formed on a first surface of a semiconductor substrate (1) of the first conductivity type, having a first terminal on the first surface of the substrate and a second terminal electrically connected to the opposite surface of the substrate through an overdoped region of the same conductivity type as the substrate, more conductive areas (11) being formed at determined places of the spiral.

Abstract: A resistance heating element of the ribbon type for use in a high temperature electric furnace. The element has the same curved cross-sectional configuration throughout its entire length to give it strength and stiffness and permits the element to be bent into various patterns without any overlapping portions at the bends. The curved cross-section permits the element to be supported at the bends without the element sagging reducing the amount of heat absorption by the supports and allowing greater exposure of the element.

Abstract: An electric hair curler comprises a handle and a barrel connected thereto for winding thereabout the hair. The barrel is provided with an electric heater for curling the hair wound on the barrel. The heater includes a plurality of resistor elements in the form of strips extending along the length of the barrel in generally parallel relationship with one another and being electrically connected in series by a corresponding number of bridging segments. The heater thus constructed is mounted on the barrel with the resistor elements thereof being exposed on the outer surface of the barrel in circumferentially spaced relationship with one another around the barrel, so that each of the resistor elements is in direct heat transfer contact with the hair to be wound on the barrel, thus greatly reducing the heat loss to assure effective heat transfer from the heater to the hair.

Abstract: A heating unit combining a block of thermal and electrical insulating material and an electrical resistance element in which the block contains a mass of ceramic fibers bound together and has an elongated slot with confronting walls rising to the surface of the block from opposite sides of a land, and the resistance element is in the form of a thin member constructed of a continuous resistance wire which is provided with opposite bends to form a serpentine shape, the bends being embedded in the opposite walls of the block to secure the electrical resistance element on the block, and the resistance element abutting the land of the slot between the walls thereof.

Abstract: This heating body is cut from a metal sheet (1) and defined by slots (2) obtained by punch stamping on a support (4) of plastics foam. The opposite edges of these slots (2) are spaced from one another by deformation of the portion of the conductor (7) adjacent to these slots, obtained by the bevelled shape of the portion of the cutter (3) defining the cutting edge and by the compressibility of the material forming the support (4). According to the method of manufacturing this heating body, its external profile and the slots (2) are obtained by a same single punching operation.

Abstract: An electric resistance heating unit in which the heating element is a thin, foil-like strip of expanded metal supported on edge substantially along its entire length on a board of insulating material. The heating element is formed in a serpentine pattern, and its bottom edge is embedded in a similar serpentine groove in the upper surface of a ceramic fiberboard and cemented therein.

Abstract: A flask heater assembly for spherical bodied, boiling flasks in which a block is hollowed to receive the flask body and a ribbon of electrical resistance heated, flexible metal is folded into an elongated band and bent and fitted into the hollow to conform with the shape of the flask. A reduced voltage current is supplied to the ends of the ribbon to produce a temperature on the order of 400.degree. C., i.e., well below the glow temperature of the metal.

Abstract: A drip edge strip for a shingled roof is tapered and includes a first portion to be secured to the roof and provided with channels extending from end-to-end thereof and a second portion to underlie the first course of shingles and to cover the channels. A heating cable extends lengthwise of the channels.