Abstract: In a flat plate type thick film resistor, an insulation performance is improved by excluding the nonuniformity of potential distribution on a wiring plane, which is generated when electric current flows in a resistance wire. Simultaneously, generation of noise depending on potential distribution and variation of stray capacitance around a resistor is suppressed. When the resistance wire having a constant thickness and uniform resistivity, which is formed on an insulating substrate, is connected to a pair electrode conductors that face to each other, in the way that the resistance wire is repetitively bent to the alternate side in zigzags, a potential gradient on the wiring plane, which is generated when electric current flows in the resistance wire, is constant by properly selecting the line width, the bending angle, and the spacing between bending vertexes of a resistance wire.

Abstract: A heater for heating a rigid fluid line or hose for freeze protection. The heater has a base made of an outer base layer, a middle base layer attached to the outer base layer; and an inner base layer attached to the middle base layer. The inner base layer can be uncured silicone (before assembly processing). A resistance wire is wound around an electrically non-conductive core and located on the inner base layer. The resistance wire can be a high gauge wire providing for a small moment of flexure. A cover includes an inner cover layer covering said resistance wire. This inner cover layer can be uncured silicone (before assembly processing). A middle cover layer is attached to the inner cover layer, and an outer cover layer is attached to the inner cover layer. The outer cover layer protects the heater from abrasion.

Abstract: A heating element has a flat, flexible strip of electrically insulating material around which is wound a conductor wire. A layer of fixing varnish covers the turns of the conductor wire and the flat strip. Two clips attached to the ends of the strip provide electrical contact with the conductor wire and serve to attach two electricity connection cables. The heating element can be bent without this affecting its ohm value since the fixing varnish prevents the turns of the conductor wire from moving when the strip is being bent.

Abstract: A cartridge heater assembly to be swaged has a sheath with head and slug ends. A resistance heater unit in the sheath includes a flat rectangular core, a resistance wire winding on the core, and first and second core covers, one on each side. Each end of the resistance wire extends from the core through a hole in the adjacent core cover and to the head end of the sheath. Crushable heater unit centralizers at each end of the sheath hold the resistance heater unit. Leads are connected to the ends of the heater wire and the connections are enclosed in the centralizer. A plastic bushing closes the head end of the sheath and a slug closes the slug end of the sheath. The heater assembly is filled with an insulating material and swaged, crushing the centralizers.

Abstract: A heating element for an air flow comprises a channel shaped bracket including a base and side walls at right angles thereto within which is mounted a pair of mica sheets arranged parallel to the base and at right angles to the sides and connected to the sides by ribs longitudinally of the sides with transverse slots within which the sheets slide. Each sheet is wrapped with a heating wire formed into helical coils so that each side of the sheet carries a plurality of parallel helical coil portions with connecting portions wrapped over the edges of the sheet. The sheets are symmetrical and one is inverted relative to the other. Each sheet carries at ends thereof a male and a female connector of the blade and receptacle type so that the blade of one sheet engages into the receptacle of the other sheet.

Abstract: A surface mount wirewound resistor having a conventional wirewound resistor embedded in a plastic body member with terminal axial leads of the resistor being severed at the opposite ends of the body member. A U-shaped metallic terminal pad or clip is secured to the ends of the body member and is in electrical contact with the severed ends of the axial leads. The upper and lower portions of the terminal pad are in coplanar relationship with the upper and lower surfaces of the body member. An alternate surface mount wirewound resistor has metallic tabs that extend from the resistance element embedded in the plastic body member, with the tabs being bent upwardly from the ends thereof and into coplanar relationship with the upper surface of the body member.

Abstract: A method of manufacturing a reinforced strip of insulative material comprising the steps of extruding a thermoplastic insulative material in the shape of a tube or spaced apart strips about a plurality of separated and substantially parallel reinforcing strands positioned within said tube or strips and compressing and cooling the tube or strips to form a flattened single strip having opposed flattened sides with the reinforcing strands firmly secured therebetween is disclosed. A reinforced support for a ballast resistor manufactured in accordance with the described method is also disclosed.

Abstract: A rotary electric machine including a stator with a rotor journalled for rotation within the stator about an axis and carrying an electrical conductor. The resistor is mounted on the rotor and is electrically associated with the conductor. The resistor is narrow axially of the rotor and elongated radially but within the periphery of the rotor to thereby provide an axially compact rotary electric machine.

Abstract: An electrical heating element (18) for heating a plate, e.g. a glass ceramic plate (14) has a multilayer insulating support (12) in whose dish-shaped depression heater coils (18) are arranged in spiral form. The heater coils are located on the insulating support surface (17) and have downwardly directed deformations (19) comprising a turn pressed out in the downwards direction. These deformations (19) are embedded in the surface layer (16) of the insulating support, which is mechanically stronger and more thermally conductive than the underlying insulating layer (15). The deformations are produced in a mould (22, 23) carrying the heater coils in slots (21) and by means of a bladelike punch (24) a turn is pressed into a depression (25). The connection between heater coil (18) and insulating support (12) during the moulding thereof comprises a loose insulating material, the heater coil and deformations being placed in slots (27) of mould part (26).

Abstract: A pressure unit assembly for providing an electrical signal representative of sensed pressure, for example an oil pressure unit assembly for an automobile engine. The unit is adapted for fabrication by automated equipment and it makes efficient use of constituent materials. Novel features of the unit include its spring contact element, its resistive element, and its electrical terminal configuration.

Abstract: A method of manufacturing a reinforced strip of insulative material comprising the steps of extruding a thermoplastic insulative material in the shape of a tube or spaced apart strips about a plurality of separated and substantially parallel reinforcing strands positioned within said tube or strips and compressing and cooling the tube or strips to form a flattened single strip having opposed flattened sides with the reinforcing strands firmly secured therebetween is disclosed. A reinforced support for a ballast resistor manufactured in accordance with the described method is also disclosed.

Abstract: An immersible heater for an aquarium includes a waterproof, heat-resisting, flat plastic case which is tripartitioned in its interior, one chamber holding a flat coil carrier bonded or welded to the case; an upper chamber contains a leaf spring actuated by a bimetallic element; these chambers are separated by a thermally isolating chamber. The bias of the bimetallic actuator is adjusted by a sealed feedthrough screw. Current flow through the heating coil is indicated by a lamp covered with a thinner wall portion of the case. The front of the case carries heat-dissipating and -stiffening ribs; the rear of the case carries suction cups.

Abstract: An electric immersion heater of planar construction for use in industrial processes is constructed of a non-corrodable material and may be immersed at the side of a processing not containing corrosive liquids. The heater includes a thin planar polymeric support frame having side members with end sections extending beyond the end portions of the frame. An electrical resistance heating element wire shrouded with an integral layer of polymeric material is wound around the end portions of the frame to form a substantially flat heating element assembly. Imperforate polymeric cover plates are secured in spaced relationship to opposite faces of the heating element assembly by spacing and securing means engaging the side members of the frame. The peripheral edges of the cover plates are spaced apart to form a gap allowing for free flow of fluid through the heater between the plates throughout the entire extent of the heater.

Abstract: There is provided a flexible electric heater element and a process for making such a heater element.The flattened ends of two lead wires are disposed on a first layer of material which includes a vulcanizable elastomer. The ends of a resistance wire are placed in electrical contact with the flattened ends of the two lead wires. A second layer of material, which includes a vulcanizable elastomer, is placed over the first layer sandwiching between the layers the resistance wire in electrical contact with the flattened ends of the two lead wires. The other ends of the two lead wires extend externally to the first and second layers of material.The elastomer is vulcanized and the flattened ends of the lead wires are held in permanent electrical contact with the ends of the resistance wire by forces exerted by the vulcanized elastomer.

Abstract: A heating element is comprised of [A] a shaped, electrically insulating substrate, said substrate including a reinforced polyimide composite, [B] a continuous, electric resistor element in entwining relationship with, and at least partially inlain within said composite [A], said electric resistor element being coated with a thermostable electrically insulating coating, and [C] means for coupling said electric resistor element [B] with an electric power source. Techniques for the fabrication of such heating elements are also disclosed.

Abstract: An electric band heater of low expansion characteristics having an integral ceramic core with resistance wire sandwiched therein and encased within a metal housing, the core being formed from a wire wound ceramic sheet sandwiched between ceramic sheets; and a method for making such a heater which includes the steps of arranging an assembly of a wire wound organic-ceramic core strip between organic-ceramic insulator strips and placing the same within a metal housing, compressing and forming the assembly and then heating the assembly to bake out organic binder materials and sinter ceramic materials into a ceramic mass.

Abstract: A wire-wound resistor has an adhesive applied to the wire and the insulative substrate upon which the wire is wound at a predetermined location. The wire is then cut or otherwise broken at that location to open-circuit the resistor. The adhesive holds the cut end of the wires in place on the substrate.