Abstract: An electromagnetic relay includes a first movable contact piece, a first movable contact, a second movable contact, a moving member, a coil, and a movable iron core. The moving member holds the first movable contact piece. The moving member is made of a resin having electrical insulation. The moving member includes a first member and a second member. The first member is connected to a movable iron core. The second member is a separate body from the first member. The second member is connected to the first member by snap fitting. The first member includes a convex portion. The convex portion projects toward the second member in a moving direction of the moving member. The second member includes an inspection hole. The inspection hole faces the convex portion in the moving direction and extends in the moving direction.

Abstract: An electromagnetic relay includes a first movable contact piece, a moving member, a coil, and a movable iron core. The movable iron core is connected to the moving member and is configured to move by a magnetic force generated by the coil. The moving member is made of an electrical insulator. The moving member includes a support portion and a connecting portion. The support portion holds a first movable contact piece. The connecting portion is connected to the movable iron core. The connecting portion includes a locking groove and a locking projection. An end of the movable iron core is disposed in the locking groove. The locking projection presses the end of the movable iron core in the locking groove. The locking projection extends in a support direction perpendicular to a moving direction of the moving member.

Abstract: An electromagnetic relay includes a first movable contact piece, a moving member, a coil, and a movable iron core. The moving member holds the first movable contact piece. The movable iron core is connected to the moving member and is configured to move by a magnetic force generated by the coil. The moving member is made of resin having electrical insulation. The moving member includes a first member and a second member. The second member is connected to the first member by snap fitting. The first member includes a first protrusion. The second member includes a second main body, a first locking portion, and a first arm. The first locking portion locks to the first protrusion. The first arm connects the second main body and the first locking portion. A thickness of the first arm is smaller than a thickness of the first locking portion.

Abstract: An electromagnetic relay includes a moving member, a yoke, a guide member, and a movable iron core. The yoke includes a plate portion and a yoke hole. The guide member is disposed in the yoke hole. The movable iron core is connected to the moving member. The movable iron core includes a tubular portion. The tubular portion includes a first end surface and a second end surface. The tubular portion is disposed in the guide member. The plate portion includes a first surface and a second surface. In a case where the moving member is located at the closed position, the first end surface is located within a range from a first position to a second position. The first position is a position corresponding to the first surface. The second position is located at a center of the first surface and the second surface.

Abstract: A micro-electromechanical (MEM) relay and its fabrication process. The MEM relay includes a movable actuator electrode anchored to a substrate with two cantilever beams. Below the actuator electrode, there are three fixed electrodes. These three electrodes are the gate, the input, and the output contacts. The square base of the actuator electrode, and the square gate electrode below it, form an electrostatic parallel-plate actuator. When a voltage is applied between the actuator electrode and the gate electrode, the actuator electrode is pulled-down due to electrostatic attraction closing the relay. When the voltage is removed, the cantilever beams act as springs opening the relay.

Abstract: A test system is a test system for conducting a test including a static characteristic test of a device under test, the test system comprising: a plurality of static characteristic units used for measurement of the static characteristic test; and a replacement unit configured to be able to attach and detach specific units among the plurality of static characteristic units, the specific units selectively used according to a measurement item.

Abstract: A method for determining the operating status of a MV switching device is provided. The method includes providing a test signal to said test coil for an observation period of time. Measuring data is obtained which is indicative of the voltage at the terminals of the test coil and of the current circulating along the test coil during the observation period of time. Observation data is calculated which is indicative of the electric behavior of the test coil at the end of said observation period of time. A transformation function is selected which is indicative of the electromagnetic behavior of the electromagnetic actuator. First estimation data is calculated which is indicative of the operating status of the electromagnetic actuator.

Abstract: A probe cover is provided. The probe cover is configured to be detachably attached to an ultrasonic probe and cover plural switches on a surface of the ultrasonic probe, the probe cover including a depression portion by which an operator can depress at least some of the plural switches when the probe cover is attached to the ultrasonic probe.

Abstract: A power receptacle with a housing having an inwardly extending chamber, the inwardly extending chamber having a depth dimension that is between 0.5 inches and 5 inches, more typically between 1 and 5 inches, sized and configured to releasably receive a portable power supply inside the chamber. The housing includes an internal electrical charging interface. When the portable power supply is in the chamber, the portable power supply electrically engages the electrical charging interface to thereby charge the portable power supply. The receptacles can be in-wall or in-floor units. The housings can be a “custom” housing size and/or may be configured to occupy a single gang box or a compartment of a multi-gang junction box.

Abstract: A relay and a method of assembling a relay are provided. The relay comprising: a relay switch configured to operate in a first switch mode and a second switch mode; a flag structure for indicating an operative status of the relay switch, the flag structure capable of being orientated in a first position for indicating the relay switch being in the first switch mode and in a second position for indicating the relay switch being in the second switch mode; a card structure coupled to the flag structure for changing the orientation of the flag structure from the first position to the second position or from the second position to the first position; and a base plate coupled to the flag structure and the card structure, the base plate comprising an open ended slot for allowing part of the flag structure to be received therein.

Abstract: An electromagnet device has a spool having a guard portion at at least one end thereof, a coil wound around a body portion of the spool, and a coil terminal press-fitted in the guard portion. A lead wire of the coil is tied up to a tying-up portion of the coil terminal projected from the guard portion. The tying-up portion is folded toward the guard portion of the spool after the lead wire of the coil is tied up to the tying-up portion of the coil terminal extending in a direction receding from the spool.

Abstract: A structure of a battery relay is provided comprising a plunger movable upward and downward. The plunger comprises a lower portion, an upper portion, and an intermediate portion. A guide is fixed to a housing and supports the intermediate portion. A return spring is disposed on the lower portion and supports the plunger. A traveling contact is integrally formed with the plunger and movable upward and downward. A stationary contact is fixedly disposed at a lower side of the traveling contact. An exciting coil is connected to a battery switch and moves the plunger downward by being excited when the battery switch is turned on. A movable spring formed as a compression spring, is disposed on an upper portion of the traveling contact, and has one end fixed to an upper end of the plunger and another end fixed to an upper end of the guide.

Abstract: A microswitch is disclosed, wherein the microswitch has (1) an electrical path between a first terminal and a second terminal and (2) a closed-loop magnetic path for channeling a magnetic field through a working gap to efficiently actuate the microswitch, where the electrical path and the closed-loop magnetic path are path independent. The electrical path includes a laterally movable mechanically active element. The closed-loop magnetic path includes one or more integrated coils for generating the magnetic field. The microswitch comprises: an electromagnetic module, which includes the one or more coils and some of the magnetic element of the closed-loop magnetic path; and a switch module, which includes the switching elements and the remainder of the magnetic elements of the closed-loop magnetic path. After the modules are joined the magnetic elements on both modules are magnetically coupled to collectively define the closed-loop magnetic path.

Abstract: The invention relates to an electromagnetic actuator comprising a housing (9) having several faces (20, 21) and an electronic control circuit (14) split into at least two parts (14a, 14b) distributed over at least two adjacent faces (20, 21) of the housing (9), each part (14a) of the circuit comprising at least one metallic connector (25a) arranged so as to be connected electrically and mechanically with a metallic connector (25b) of another part of the circuit (14b) so as to form an electrical connection (24).

Abstract: An electromagnetic opening/closing device A1 includes a detector 5 for detecting an opened or closed state of a contact unit 1; a malfunction determination unit 6 configured to determine presence or absence of malfunction based on the opened or closed state of the contact unit 1 detected through the detector 5 and an opened or closed state of the contact unit 1 corresponding to an exterior command; and an output unit 8 configured to supply an exterior with a determination result by the malfunction determination unit 6.

Abstract: Disclosed is an electromagnetic switching device. The electromagnetic switching device includes a case defining an outer appearance; a fixed contact point assembly received in the case and including a fixed contact point; a coil terminal assembly detachably coupled to one side of the fixed contact point assembly and including a coil; and a shaft assembly detachably inserted into the coil terminal assembly, wherein the shaft assembly includes a shaft movable in the coil terminal assembly.

Abstract: Methods, systems, and devices for power parameter sensing using power sensing components integrated into a relay are described. A power distribution unit may be provided with switched outputs that may provide or interrupt power provided to the output through a plurality of relays. The plurality of relays may include an integrated power sensor configured to sense one or more power parameters associated with power delivered to a respective power output. A power-related information reporting system may be coupled with the relays and configured to report power-related information derived from the power sensor to a remote system.

Abstract: Provided is a technology which has a simple structure, is easy to manufacture, and does not increase cost. A terminal member to be press-fitted into a terminal hole formed in a base, includes a press-fitted portion which is to be press-fitted in the terminal hole, and a terminal portion extending from the press-fitted portion and protruding from the base. The terminal portion is formed by folding a plate-like body such that folded portions overlap a planar portion. At least one of the folded portions has a cut-away portion extending from the base, respectively at an edge near the press-fitted portion. A sealing agent can be injected into the terminal hole via the cut-away portions.

Abstract: The starter-use electromagnetic switch has an electrical contact interposed in a power supply line for supplying power from a battery to a starter motor, the main contact being turned on and off in interlock with energization of an electromagnet implemented by an excitation coil. The electromagnetic switch includes a connection fitting connected to the excitation coil at one end thereof and drawn outside through a resin cover of the electromagnetic switch at the other end thereof, and a terminal fitting electrically and mechanically connected to the other end of the connection fitting at one end thereof, the other end of the terminal fitting being branched into first and second terminal pieces. The first terminal piece serves as an excitation terminal supplied with power from the battery. The second terminal piece serves as a connection terminal connected to an excitation terminal of an external electromagnetic switch through a cable.

Abstract: A starting switch structure including a body, plunger piston movable in the body, wherein the plunger piston has a first accommodating portion at an end of the plunger piston for accommodating an end of a guide pin moving reciprocally, the accommodating portion has a butting portion at the bottom surface, an excitation portion wound around the end of the plunger piston, and a butting part at an open end of the accommodating portion of the plunger piston, wherein a contact point is led to electrically connect the first terminal to the second in case that the plunger piston and the guide pin move in a first direction when the excitation portion excites, while a broken circuit is led between the first terminal and the second terminal in case the plunger piston and guide pin move in a second direction after the excitation portion has finished exciting.

Abstract: The present invention relates to a method for producing an electric contact element from a semifinished product and to the electric contact element and the corresponding semifinished product.

Abstract: A thermally managed electromagnetic switching device (2) is provided that includes a current carrying component set (4) switchable between a closed, current carrying state and an open, current interrupting state. A thermally dissipating component set (6) functionally supports and electrically isolates the current carrying component set (4) in the open state. The thermally dissipating component set (6) includes at least in part a thermally conductive polymer and is cooperatively configured to transfer heat away from the current carrying component set (4) in the closed state to dissipate thermal energy.

Abstract: A circuit breaker is disclosed that provides a warning that the current through the circuit breaker exceeds a warning threshold. The circuit breaker comprises: a switch that carries a current I; an indicator for alternatively indicating: (i) that the current I has not exceeded IW, and (ii) that the current I has exceeded IW; and an actuator in series with the switch that: (i) causes the indicator to indicate that the current I has exceeded IW when and only when the current I has exceeded IW, and (ii) opens the switch when and only when the current I exceeds IT; wherein 0<IW<IT.

Abstract: A sealed contact device includes an electromagnet block 2 including a coil bobbin 21, a movable iron core 25, a yoke 26, and a return spring 27; a contact block 3 including a sealing container 31, fixed contact points 32, a movable contact member 35 arranged within the sealing container 31 and composed of a rectangular body portion 35a, first and second protrusions 35b, 35c formed in longitudinal sides of the body portion 35a and movable contact points 34, and a shaft 37; and a case 4. The first and second protrusions 35b, 35c of the movable contact member 35 are formed in non-point symmetry with respect to a connection portion of the movable contact member 35 and the shaft 37 so that, when the movable contact member 35 is rotated, only one of the first and second protrusions 35b, 35c makes contact with the sealing container 31.

Abstract: A mechanical switching device including a base member, at least one pair of elongated conductor members mounted on the base member, each conductor member including a conductor end, wherein the conductor ends of the pair of conductor members are separated by a gap, a middle member mounted on the base member, a switch member including a stationary part and a movable part, the movable part including a conductor bridge. The stationary part includes a protruding member protruding away from the direction of displacement of the conductor bridge, wherein the base member, the conductor members, the middle member and the stationary part of the switch member are attached together by means of at least one attachment arrangement formed in the base member, the middle member and the protruding member.

Abstract: A leakage protective plug comprises a case and electric contacts. A protective cap is fixed on the top of the case and includes a reset button protective cap and a test button protective cap. The reset button protective cap is interiorly provided with a reset button connected with a push rod which in order penetrates an electric contact upper panel, an upper spring, an electric contact lower panel and a lower spring. The electric contact upper panel is provided at a right side thereof with a locking member linked with a brake connecting rod which is linked with a brake plate. The brake plate is located at a lower right side of the locking member. Below the brake plate are disposed an electromagnet pole shoe, an electromagnet coil, and an electromagnet core. The test button protective cap is provided with a test button having a test electric contact.

Abstract: In one embodiment of the present invention, a production method for an electromagnetic switching device includes the following steps in the sequence listed: producing a one-piece switching chamber, producing a contact bridge carrier and equipping the contact bridge carrier with movable contact bridges, wherein the contact bridges include a plurality of primary contact bridges and at least one auxiliary contact bridge; inserting the contact bridge carrier equipped with the movable contact bridges into the switching chamber; inserting partition elements into the switching chamber so that each partition element is arranged between a bridge contact point of one of the primary contact bridges and a bridge contact point of one of the auxiliary contact bridges, and equipping the switching chamber with fixed primary counter-contact points; fixing primary covers to the switching chamber so that the primary covers cover the primary counter-contact points and fix the partition elements in the switching chamber.

Abstract: A circuit breaker and method includes a mechanical pole moveable between a latched position and an unlatched position to open an electrical connection between a pair of electrical contacts. An electronic tripping device is configured to respond to a sensor signal. The sensor signal is output from a condition sensor wherein upon receiving the sensor signal the electronic tripping device trips the mechanical pole into the unlatched position.

Abstract: The invention relates to a solenoid switch for starting devices for starting internal combustion engines, comprising a joint (100) between assembled parts of the solenoid switch. The invention is characterised in that the joint is formed in such a way that a direct penetration of spray water is prevented and pressure compensation is enabled.

Abstract: This device, either applied as an aftermarket unit to an existing power supply source for a computing device, or as a single piece, factory created unit, will automatically stop all current draw from a power supply [port] when a computing device is disconnected at its charging connection at the port end without the need to be unplugged from a main power source. This one simple device will stop the waste of electricity and, therefore, stop the waste of precious natural resources.

Abstract: A switching device for a vehicle having an electronic immobilizer includes at least one part which is fixedly mounted in relation to the vehicle and at least one sensing device which can move relative to the fixedly mounted part. The switching device further includes at least one induction coil which is provided for communication with a transponder that is integrated into a portable device. The induction coil is at least partially integrated into the movable sensing device.

Abstract: A magnetic switching device includes an electromagnetic component adapted to be arranged proximate to an exterior surface of an object having a magnetically-switchable device therein and a control circuit electrically connected to the electromagnetic component. The electromagnetic component is constructed to generate a magnetic field of sufficient strength and orientation to engage a switch in the magnetically-switchable device. The invention further includes an electrocautery system, including an electrocautery device, a control circuit electrically connected to the electrocautery device, and an electromagnetic component electrically connected to the control circuit. The electromagnetic component is adapted to be arranged proximate to an exterior surface of an object having a magnetically-switchable device therein. Operation of the electrocautery device causes the electromagnetic component to generate a magnetic field of sufficient strength to engage a switch in the magnetically-switchable device.

Abstract: A electromagnetic relay in which bad electrical contact and failure of operation are prevented even when shavings are produced while an iron core is press-fitted into and mounted on a base. The electromagnetic relay includes an electromagnetic block supported by press-fitting both ends of an iron core of the electromagnetic block into an upper surface of a base and open or close a contact by a movable iron piece rotated by magnetization or demagnetization of the iron core with a coil, where shaving receptacles are made by forming separating ribs adjacent to at least one side of press-fit projections that are formed in press-fit concave portions provided on the upper surface of the base.

Abstract: A power switching apparatus includes a breaker unit, an operating unit, a measuring unit, and a controlling unit. The breaker unit is connected on a three-phase current line, and includes switches each corresponding to one of phases of the three-phase current line. The operating unit simultaneously turns on or off the switches. The measuring unit measures a current flowing in each phase, and determines a time point where current flowing in one of the phases becomes zero as a reference time point. The controlling unit controls, when interrupting load current, the operating unit to turn off the switches in a range from 20 degrees to 40 degrees of an electric angle from the reference time point.

Abstract: Magnetically latching and releasing a voice coil actuator for controlling electrical switchgear. The voice coil actuator includes a voice coil magnet disposed on a common longitudinal axis with respect to a voice coil assembly. A coil of the voice coil assembly exerts a magnetic force on the voice coil assembly, thrusting the voice coil assembly towards the voice coil magnet. At least one pair of latching members mounted to the voice coil assembly creates a permanent magnet circuit between the latching members and the voice coil magnet. The permanent magnet circuit maintains the position of the voice coil assembly relative to the voice coil magnet, even when power to the coil is removed. This latch can be released by applying a current in the coil or by applying an external, physical force to a member coupled to the voice coil assembly.

Abstract: Embodiments of the present invention provide a method and a device for line-switching in an automated main distribution frame (AMDF) which may solve the problem of contact point damage which may occur during hot switching of micro electromechanical system (MEMS) matrix, and further solve the corresponding problems which may occur during the line-switching in AMDF. In particular, the present invention is preferably embodied in the following way: when switching operation of a switch unit in MEMS is to be performed, the current introduced into MEMS matrix is firstly cut off, and is then recovered when the switching operation is finished, so as to prevent the “agglutinate” phenomena. Therefore, the present invention provides corresponding protection for the switching process of MEMS matrix relays in AMDF, and effectively prevents the “agglutinate” phenomena when the switch unit in MEMS matrix performs switching operation, whereby the reliability of AMDF is enhanced.

Abstract: Disclosed is an apparatus for selectively permitting electricity to flow to a power tool having a power cord. The apparatus comprises a body having an exterior surface and having a passage therethrough. The passage contains an electrical relay having an electrical input side and an electrical output side. A switch on the exterior surface of the body selectively closes the electrical relay upon activation by a user. A mounting portion on the body is adapted for securing the body to the power tool and a power receiving portion in the body receives the power cord of the power tool. The mounting portion has transfer wires associated therewith in electrical connection between the output side of the relay and a power switch of the power tool. The power cord is in electrical connection with the electrical input side of the relay.

Abstract: The invention relates to a device for switching at least one current includes a switching mechanism located in a switching chamber. The switching mechanism interrupts and connects a current path in an orderly fashion. Switching devices frequently have a protective function, e.g. relative to a power grid, and it is therefore desirable for supporting the protective function to identify faults and/or wear within the switching device. To this end, the switching device includes at least one temperature measuring unit that aids in detecting faults and wear within the switching device.

Abstract: The invention relates to an electrical switching device, having a thermal release, an electromagnetic release, and a switching mechanism with a latching point. A contact base for moving a contact member is located between the thermal release and the electromagnetic release. The thermal release is coupled to a release lever by means of a connecting rod passing over the contact base so that both the thermal release and the electromagnetic release open the latching point in the event of an overcurrent and/or short-circuit current.

Abstract: An electrical switchgear includes a thermal trip, an electromagnetic trip, and a switching mechanism with a latching point and at least one contact point that is continuously opened or closed. An operating handle is connected to one end of a lug by means of a coupling element and the other end of the lug is coupled to a contact base that carries a moving contact member. The thermal trip is coupled to a trip lever by a connecting rod that passes over the contact base so that both the thermal trip and the electromagnetic trip open a latching point in the event of an excess current and/or short circuit current.

Abstract: A relay has a main body with a base. An electromagnetic switching mechanism is arranged on the base. A contact arrangement includes at least one stationary contact spring and at least one moveable contact spring arranged on a first side of the main body. The moveable contact spring has a first portion extending substantially perpendicular to the base that is actuatable by the electromagnetic switching mechanism and a second portion extending substantially parallel to the base that extends from the first side of the main body to an opposing second side of the main body. A terminal contact extends from the second portion on the second side of the main body.

Abstract: A rugged, miniature, waterproof and lightweight magnetic latching indicator with an auxiliary switch. The indicator includes a solenoid, an elongated plunger mounted in the solenoid, the plunger supporting a first permanent magnet with the magnet being surrounded by specially dimensioned non-magnetic spacers. The plunger and solenoid are packaged in a non-magnetic housing with a solenoid locator, a top cap and a bottom cap maintaining the indicator in a compact waterproof package. An indicator button is mounted to the plunger and a reed switch biasing spring and second permanent magnet are located between the bottom cap and the solenoid. The plunger moves from a retracted latching position to an extended position. In the retracted position, the indicator button is retracted and not readily visible and the second permanent magnet maintains the reed switch in a closed position.

Abstract: Structure and method for forming a switchable shunt for a suspension assembly having conductive, insulating and metal base layers. The shunt includes a bridge in the conductive layer with either a continuous connection or small gap between ends of the bridge. The continuous connection of the bridge is severed either by temporarily moving the lands out of their original plane by stretching and rupturing the bridge or by shearing the continuous connection of the bridge. For the sheared or gapped bridge, at least one end of the bridge is moved out of plane, compressed and elongated. When released, the separated ends of the bridge overlap and contact each other to form a normally-closed switch. To subsequently open the switchable shunt, at least one of the lands is moved out of plane to physically and electrically open the connection between the separated and overlapped ends of the bridge.

Abstract: A circuit breaker includes separable contacts and an operating mechanism having a cradle for opening and closing the separable contacts. A trip mechanism cooperates with the cradle of the operating mechanism to trip open the separable contacts. The trip mechanism includes a bimetal conductor, which is electrically connected in series with the separable contacts. The trip mechanism is responsive to a predetermined condition of current flowing in the bimetal conductor. The trip mechanism also includes a magnetic yoke coupled to the bimetal conductor, an armature pivotally mounted to the magnetic yoke, and a spring biasing the armature away from the magnetic yoke. The spring is set apart from the bimetal conductor. The spring is coupled to the armature and engages the magnetic member.

Abstract: A unitary operating mechanism assembly for a circuit breaker that includes a frame assembly having a planar member with a first pivot point located thereon, a handle member rotatably attached to the frame assembly at the first pivot point and structured to move between a first, closed position, a second, open position having an intermediate position therebetween, and a third, reset position, an operating arm coupled to the handle member and structured to move between a first and second position, and a trip device attached to the frame assembly and structured to move the handle member between the first, closed position and the intermediate position upon the occurrence of a predefined condition. The trip device causes the handle member to rotate upon the occurrence of a predefined condition, such as an overcurrent, thereby causing the operating arm to rotate and wherein none of the components except the frame assembly is attached to the housing.

Abstract: A hermetically sealed electrical switch assembly comprises a casing having an opening end. A cover is sealingly attached to said opening end of said casing for forming a primary volume hermetically sealed from external environment. Received in said primary volume are a switch means and a magnetic responsive means. A magnetic activating means is fitted at the upper surface of said cover for effecting the movement of said magnetic responsive means. The switch means comprises electrical contacts to change the conducting state of a power circuit with which said switch means is connected, a switching lever which can change its positions according to the conducting state of the power circuit. The magnetic responsive means couples with said switching lever for moving with it.

Abstract: In the conventional fluid level detector, the reed switch is accommodated in the housing formed of an insulating material such as a resin or the like to prevent the reed switch from coming into direct contact with fluid and being electrically shorted. However, since such a construction requires the steps of storing and fixing the reed switch in the housing and leading out the lead therefrom, workability is low, the housing must be manufactured separately, and thus the cost increases. Accordingly, a reed switch wherein at least the tubular bulb portion is molded with a hot-melt resin is provided.

Abstract: In one embodiment, a semiconductor device having single or multi-layer intermediate layers that easily adhere to a glass frit and lead lines of respective interconnections is disclosed. In general, the single or multi-layer intermediate layers are formed on at least the top surfaces of portions of the respective lead lines on which the glass frit is placed.

Abstract: An electromagnetic actuator comprising a stationary member, a movable member magnetically coupled with the stationary member with a gap therebetween, and a support member for displaceably supporting the movable member relative to the stationary member. Both the stationary member and the movable member have a core section carrying a coil wound around its periphery. As the coil of the stationary member and that of the movable member are energized with electric current, the movable member is attracted toward or repulsed from the stationary member. The electromagnetic actuator can be used for an optical scanner by providing a mirror or a lens on the movable member.

Abstract: In order to prevent a mistrip caused by a closing operation of a toggle link mechanism, a trip lever is not mounted on a fixed frame of an opening/closing mechanism, but is mounted on a yoke of a disengaging device serving as a support base for the trip lever. The opening/closing mechanism and the disengaging device are held in a common casing. As a result, an impact force, produced at the time of closing the contact between two contacts by the toggle link mechanism, is transmitted through the casing, so that such a mistrip can be prevented.