Abstract: Low voltage current limiting fuses wherein the conventional fusible element is replaced. The fuses of the invention are resettable manually or automatically such that the fuse need not be physically replaced following a fault current or overload current occurrence in the external circuit in which the fuse is incorporated.

Abstract: An actuator with an electrically heatable operating element, the housing of the operating element being held stationary in a mount of a base body, and a transfer element, which comprises two plastic molded parts, is provided between the piston and the element to be adjusted.

Abstract: A thermostat includes a valve for controlling gas flow, an actuator for controlling operation of the valve, and a temperature sensing element. The temperature sensing element comprises two members, one of which is made of a material having a positive coefficient of thermal expansion and the other of which is made of a material having a negative coefficient of thermal expansion. Each member effects movement of the actuator in a first direction upon sensing a decrease in temperature to effect opening of the valve and in a second direction upon sensing an increase in temperature to effect closing of the valve.

Abstract: A T-shaped member is pivotally mounted to a support plate, and has first and second shape memory wires attached at first ends thereof to opposing portions of the T-shape. Second opposing free ends of the shape memory wires are secured to the support plate. Electrical current is conducted alternately through the first and second shape memory wires to cause the wires to contract in alternating tandem, to thereby cause the T-shaped member to move between first and second positions. Pivotal movement of the T-shaped member can be used to actuate and/or reactivate a switch device.

Abstract: A thermally-actuated switch includes a pair of switch contacts openable or closeable in response to a change in the length of a shape memory metal (SMM) rod. The SMM rod is caused to change its length by having its temperature increased by heat produced when electrical power dissipated in a heating element that is coupled in electrical circuit with the switch contacts. To this end, the heating element is thermally coupled to the SMM rod, such as by a common heatsink. Where the switch is to be openable, the heating element is preferably in series circuit with the contacts, and where the contacts are closeable, the heating element is preferably in parallel therewith.

Abstract: A relay including a control circuit which via a movement creating or actuating arm and a transmission mechanism activates a contact means in order to switch on or switch off a main circuit. The actuating arm includes two elongated parallel parts which are separated by a thermally and electrically insulated layer. The two parallel parts each have a first end fastened to a housing or holder. The two parallel parts each have a second end fixed to each other, forming a movable end of the arm. One or both parallel parts of the arm are provided with a heat creating or producing element. The actuating arm, attached at one end and movable at the other end, together with the heat producing element, constitutes the first part of the control circuit or relay. When a control current flows through the heat producing element, one of the two parallel parts of the arm is heated thereby causing a movement of the movable end of the arm to thereby activate the control means through the transmission mechanism.

Abstract: A temperature switch for limiting the temperature of a glass ceramic plate against the radiation emanating from light and dark radiators has a sensor, which comprises a metallic sensor tube and an inner ceramic rod. Over the sensor is drawn a steatite tube, which on the one hand ensures the electrical insulation between the heaters and the glass ceramic plate and on the other so shields the radiation by reflection, absorption and thermal mass, that the sensor is given a temporary response delay and a greater switching hysteresis.

Abstract: An arm preferably for electric switches, the arm being controlled by electricity, and having a first fixed end the other end of which is movable perpendicular to the length direction of the arm. The arm comprises two parallel portions (47) separated by an air gap (17) or some other heat insulating material, and which are secured to each other at each end. At least one of the portions, being heated by electricity and, through longitudinal differential expansion with respect to the other portion, achieves said movement. The portions are so shaped that, adjacent the fixed end (at 45) with respect to the rest of the portions, they have a reduced bending resistance about an axis which is perpendicular to the length direction of the arm and with respect to said direction of movement.

Abstract: A base body with a big cavity in its center, a frame body encased in the cavity and retained therein by the ends of the shorter legs of the U-shaped contact plates is disclosed. During an overload condition, overheating causes a spring engaging the clipper plate to expand, which frees the frame body from the shorter legs of the contact plates and the frame body is ejected upward by a coil spring inside the frame body. The frame body is detained in the cavity of base body when freed from the shorter legs of the contact plates by engagement between flanges on frame body and the ends of the longer legs of the U-shaped contact plates, and an LED trouble indicator is used to indicate the overload condition.

Abstract: A temperature-dependent switch is provided with a substance, which expands when heated in a housing, and a transmission part. The transmission part is displaceable by a diaphragm, a sealing part, accepting a beaded edge on the diaphragm with an annular groove is included. The integral housing serves to accept the substance which expands or contracts as a function of temperature, the sealing part, the diaphragm and the transmission part. A prong plate is fastened to housing for at least one electrical prong. The scaling part is provided with at least one recess to accept an insulating part. The transmission part is effectively connected with an electrical prong.

Abstract: A differential expansion rod and tube thermostat wherein the material of the inner rod has a much lower coefficient of thermal expansion than does the material of the outer tube. The thermostat is adapted to be mounted through an opening in the wall of an oven cooking cavity. A certain amount of the tube remains outside the oven cooking cavity. The inner rod is adapted to lie within the oven cooking cavity. Joined to the inner rod is an extension strap of a material having a high linear coefficient of thermal expansion substantially the same as that of the outer tube. The longitudinal motion created by the difference in the rates of expansion between the outer tube and the combined inner rod and extension strap is transferred by a hinged amplifier lever to a switch mechanism which is calibrated to operate at a predetermined oven temperature.

Abstract: A thermal fixing device for a xerographic reproducing apparatus includes a thin planar resistance heating element having a low thermal mass and a high coefficient of thermal expansion. The heating element is supported in such manner that one end thereof is free to move linearly under thermal expansion to activate a heater displacement detector comprising a pivotally mounted lever arm having a right angle configuration. One end of the lever arm is received in an opening in the heating element and the other end form a contact of a normally open switch which is adapted to be closed by pivoting of the arm due to expansion of the heating element. Closure of the switch activates a power controller to interrupt the power supply to the heating element.