Abstract: A heater strip (12) is disposed in spaced relation to a temperature responsive actuator element (20) for indirectly heating that element in response to current flow in the heater (12). An adjustable heat sink (22) is disposed in spaced proximity to the actuator element (20) for removing heat from the actuator element by radiation therefrom through air to the heat sink in a first position and adjustable to be in thermally conductive engagement with the actuator in a second position for increasing the efficiency of heat transfer from the actuator to the heat sink. Increased current flow in the protected branch circuit is required to cause the actuator (20) to attain its predetermined actuation temperature as the heat sink is adjusted to increase the efficiency of heat transfer between the actuator (20) and the heat sink.

Abstract: The invention provides a magneto-thermal device for overcurrent relays.The end of a core, whose axial position may be adjusted with respect to a mobile plate, placed opposite and pivoting about one end of the yoke, is secured against movement by a wedge which is guided in a groove belonging to a flange of the coil shell.This device may be used in any thermal relay where a stable and precise adjustment of the tripping current threshold is desired.

Abstract: A mechanically controlled power switch with automatic opening is provided for limiting short circuits. A switch (13), a breaking chamber (30) which is associated therewith, a coil (50), a striker (51) cooperating therewith, and a lock (53) for holding the power switch in open position S after the appearance of a short circuit are placed in a removable cartridge (23) provided with connection terminals (37, 55). This switch cartridge is advantageously used in mechanically controlled protection apparatus or in electromagnetic contactor apparatus having their own protection.

Abstract: An electric circuit breaker including a U-shaped bimetal operably associated with a trip crossbar to effect rotation of the crossbar and subsequent opening of breaker contacts in response to heating of the bimetal to a predetermined temperature by the passage of an electrical current of a selected magnitude therethrough. The bimetal provides self-contained adjustment through the use of a calibration screw threaded into the lower leg of the bimetal which exerts force through an insulating member to the upper leg of the bimetal permitting ready calibration of the bimetal according to ampere rating of the particular circuit breaker.

Abstract: A circuit breaker comprising a solenoid coil, an armature actuatable by the coil and a magnetizable frame carrying the coil enclosed with a case comprising two abutting half-cases. A time delay device comprising a tube of non-magnetic material within which is a movable magnetizable core and with which the coil cooperates to actuate the armature after a time delay period upon predetermined energization of the coil. The tube has a pole piece at one end and the armature has an attractable portion which moves toward said pole piece on predetermined overload conditions, the core being biased toward the end of the tube away from the pole piece. An adjustable cam is carried between said half-cases. Said attractable portion of the armature being biased by a spring into engagement with said cam and away from said pole piece. Said cam being rotatable to vary the air gap between said pole piece and said attractable portion of the armature, whereby the trip point of the circuit breaker may be varied.

Abstract: In a push button actuated, bimetal controlled, current overload switch capable of undergoing trip-free release and including a bimetal strip disposed in a housing, an angular contact bridge disposed in the housing and forming part of the current path provided by the switch, a switching rod mounted in the housing for axial movement relative thereto and having one end extending out of the housing, a switching rod extension mounted at the other end of the rod and within the housing and arranged to bear against the bridge, and a spring disposed to maintain a spring force between the bridge and the extension, opening of the switch by actuation of the rod is made possible by the provision of an obliquely extending lever disposed in the housing, having one end pivotally secured to the housing, having its other end engaging the bimetal strip, and located in the path of travel of the extension during axial movement of the rod into the housing for enabling such movement of the rod to displace the lever in a direction t

Abstract: A single-pole circuit breaker or a plural-pole circuit breaker of the type having a common trip bar extending between poles whereby any pole tripping acts therethrough to trip the other pole or poles. The breaker is provided with an improved trip mechanism comprising a subassembly for each pole wherein all of the thermal and magnetic trip elements are mounted on a breaker terminal plate that acts as a base therefor and which is secured to the breaker housing.

Abstract: A circuit breaker designed for automated assembly includes pairs of fixed and movable contacts, the latter carried by a carrier mounted for reciprocating movement in the breaker case. Operating and trip mechanism parts are mounted on a frame positioned in the case. A handle slideably mounted by the case actuates the operating mechanism to open and closed circuit positions. A fixture is utilized with the frame for calibrating the thermal trip setting and for partial assembly of the operating mechanism.

Abstract: A molded case circuit breaker is described including a U-shaped thermal and magnetic trip assembly pivotally supported by an insulating housing. A compression spring biases the trip assembly against a releasable cradle which is engaged by a latch. The biasing action of the spring against the pivoting trip assembly maintains a constant latch bite despite warping or other mechanical distortion of the insulating housing.

Abstract: A multi-pole circuit breaker with adjustable thermal trip unit characterized by a circuit breaker mechanism having a plurality of pole units, means releasable when released from a latched position to effect simultaneous opening of the circuit breaker contacts, a multi-pole trip device including trip means for each of said pole units, each of said trip means being constructed to operate upon the occurrence of certain current conditions to effect release of said releasable means, and each pole unit comprising a bimetal element responsive to current flow to effect heating thereof.

Abstract: A multi-pole circuit breaker with adjustable thermal trip unit characterized by a circuit breaker mechanism having a plurality of pole units, means releasable when released from a latched position to effect simultaneous opening of the circuit breaker contacts, a multi-pole trip device including trip means for each of said pole units, each of said trip means being constructed to operate upon the occurrence of certain current conditions to effect release of said releasable means, and each pole unit comprising a bimetal element responsive to current flow to effect heating thereof.

Abstract: A circuit breaker characterized by a stored energy mechanism and an improved resettable latch means which latch means include an adjustable thermal trip unit.

Abstract: In an electrical circuit breaker having a bimetal element which deflects, upon passage of excess currents, to displace a movable member to trip the circuit breaker, an adjustable element, in the form of a wedge, is provided between the bimetal element and the movable member, so that variation of the position of the wedge and the effective thickness thereof between the bimetal element and the movable member varies the amount of deflection of the bimetal element required to trip the circuit breaker.

Abstract: An electrical circuit breaker having a thermal element which on being heated by fault current trips the breaker, and including an adjustable member to vary the action of the thermal element thereby to vary the rating of the breaker, said adjustable member comprising a slide displaceable by an eccentric boss rotatable by means of an external knob.