794results about "Circuit-breaking switch details" patented technology

The invention discloses a molded case circuit breaker, which comprises a shell, and an electric operating mechanism is arranged in the shell. The electric operating mechanism comprises a moving contact action assembly with a rotating block and a shifting rod, a sliding block which is arranged on the shell in a sliding manner and can drive the shifting rod to shift, an operating shaft which can drive the sliding block to slide and is provided with an operating hole site, and a motor speed reduction assembly which can drive the operating shaft to rotate, and the operating shaft is in linkage connection with a shifting shaft block; the sliding block is provided with a matching groove corresponding to the shifting shaft block, the operation shaft rotates to drive the shifting shaft block to shift in the matching groove so as to drive the sliding block to slide, the shell is provided with a cover plate capable of shielding the operation hole position in a sliding mode, and the shell is further provided with a rotating lock and a tripping button located on one side of the rotating lock. By arranging the locking microswitch, the manual microswitch, the first microswitch and the second microswitch, signal feedback of a manual operation state, a rotating lock locking state and a current circuit breaker state can be realized.

The invention discloses a rapid fusing device for adaptive overload protection, and belongs to the technical field of overload protection. Comprising a multi-dimensional monitoring module used for collecting circuit current, environment temperature and humidity and equipment operation parameters in real time; the intelligent processing module is internally provided with a self-adaptive algorithm unit, and dynamically calculates and adjusts a multi-stage fusing threshold value based on real-time acquired data; the rapid execution module comprises a composite fusing structure and an arc extinguishing unit, and the composite fusing structure executes overload early warning, graded fusing or complete cutting action according to the multi-stage fusing threshold value; and the communication interaction module is used for realizing device state remote monitoring, threshold parameter remote configuration and fault information uploading. Parameters such as current, temperature and humidity are collected in real time through the multi-dimensional monitoring module, a multi-stage fusing threshold value is dynamically adjusted in combination with a self-adaptive algorithm of the intelligent processing module, the limitation that the threshold value of a traditional fuse is fixed is broken through, load fluctuation and environment change can be accurately adapted, and mistaken fusing or protection lag is avoided.

The invention discloses a dual redundant drive type self-adaptive double-speed circuit breaker, and relates to the technical field of circuit breakers. Comprising a main body, a locking assembly is arranged on one side of a connecting piece, a cleaning assembly is arranged at the top of a second bevel gear, and a moving assembly is arranged in a cleaning plate, a lead screw rotates to drive a sliding column to move, then a base is driven to move synchronously, and the base moves to drive a positioning column to move into the connecting piece; the sliding column drives the lock catch to rotate through an inclined plane arranged on the sliding column, the lock catch and the protruding position of the connecting piece are in a locking state after the lock catch rotates, the position of the touch panel in a disengaged state is locked, and potential safety hazards caused by the fact that the touch panel makes contact with the contact again after a worker mistakenly touches the handle are prevented. And after the inclined surface of the sliding column is separated from the lock catch, the lock catch is driven to rotate through the first spring, so that the locking of the connecting piece is released.

The invention relates to the technical field of circuit breakers, in particular to a fast breaking circuit breaker which comprises a shell and a contact assembly arranged in the shell, the contact assembly comprises a movable contact arranged in a rotating mode and a fixed contact arranged in a fixed mode, and a movable contact driving arm is further arranged in the shell in a rotating mode. The moving contact driving arm is used for driving the moving contact to rotate until the moving contact is disconnected with the static contact, an electromagnetic tripping assembly is further arranged in the shell, the electromagnetic tripping assembly comprises a driving piece and a transmission piece arranged in a rotating mode, and the transmission piece is used for abutting against the moving contact driving arm to limit rotation of the moving contact driving arm. And the driving piece is used for generating magnetic force and enabling the transmission piece to rotate until the transmission piece is separated from the moving contact driving arm. Through the innovative design of the electromagnetic tripping assembly, rapid breaking of the circuit breaker is realized.

The application discloses a quick closing operation mechanism of a circuit breaker, which comprises a shell, a handle, a static contact support, a movable contact support, a linkage and a tripping mechanism, the handle and the movable contact support are rotationally arranged in the shell, a contact torsional spring is arranged between the shell and the movable contact support, a long circular hole is arranged on the movable contact support, a pin shaft is arranged in the shell and passes through the long circular hole, and the movable contact support rotates relative to the pin shaft; an installation area is arranged in the shell, an energy storage limiting piece is slidably arranged in the installation area, a movable area is arranged on the handle, an abutting portion is arranged on the movable contact support, the energy storage limiting piece is provided with a moving portion and a matching portion which are arranged in the movable area, the application can make the movable contact support move beyond the stroke, is not limited to a fixed point, improves the contact force, and based on the energy storage limiting piece, the last action of closing is realized to store energy, the oxides between the movable contact and the static contact can be quickly broken down, and the overall closing effect is improved.

The invention discloses an automatic circuit breaker handcart for a switch cabinet, and belongs to the technical field of circuit breakers, the automatic circuit breaker handcart for the switch cabinet comprises a bottom frame, the bottom frame is movably provided with a circuit breaker handcart, the circuit breaker handcart is provided with a plurality of arc extinguish chambers, and the arc extinguish chambers are provided with moving contacts. A front frame is installed at one end, far away from the circuit breaker handcart, of the bottom frame, an aviation socket located on one side, far away from the circuit breaker handcart, of the front frame is arranged on the bottom frame, a signal lead is installed on the aviation socket, and a pushing assembly connected with the circuit breaker handcart is arranged between the circuit breaker handcart and the front frame. A movable transmission assembly movably connected with the pushing assembly is arranged in the bottom frame, moving assemblies movably connected with the movable transmission assembly are arranged on the two sides of the bottom frame, a camera and a temperature sensor are installed on the top of one side of the front frame, and a third contact sensor is installed on the bottom frame. The device has the advantages of intelligent detection, ordered movement, full contact of moving and static contacts, safety, reliability, convenient operation, simplicity, convenience and practicability.

The invention belongs to the technical field of switches, and particularly relates to a circuit breaker or an isolating switch, which is characterized in that a backflow channel structure is additionally arranged on the side wall of an arc extinguish chamber, after the circuit breaker or the isolating switch arches, an arc moves upwards, the pressure above the arc extinguish chamber is increased, and the pressure in a middle area of a moving contact and a static contact below the arc is reduced; the backflow channel is used for supplementing the upper cold gas to the post-arc space gas, arc falling is inhibited, and the arc extinguishing performance of the product is improved.

The utility model relates to a circuit breaker, which comprises a shell, an operating mechanism, a moving contact, a static contact and an arc extinguishing mechanism, the operating mechanism, the moving contact, the static contact and the arc extinguishing mechanism are arranged in the shell, the arc extinguishing mechanism comprises an arc extinguishing chamber, the arc extinguishing chamber comprises a first arc extinguishing grid plate group, and the first arc extinguishing grid plate group is composed of a plurality of first arc extinguishing grid plates. The first arc extinguishing grid sheets are arranged along the horizontal direction or are arranged at an included angle of-alpha-alpha relative to the horizontal direction; the arc extinguish chamber comprises a second arc extinguish grid sheet group which is composed of a plurality of second arc extinguish grid sheets and is arranged below the first arc extinguish grid sheet group, and the inlet end of the second arc extinguish grid sheet group is close to the moving track of the moving contact. The second arc-extinguishing grid sheets are obliquely arranged at an angle beta relative to the horizontal direction, and the outlet ends of the second arc-extinguishing grid sheets incline towards the outlet end direction of the first arc-extinguishing grid sheet group; alpha is smaller than 20 degrees, and beta is larger than 45 degrees and smaller than 90 degrees. And by optimizing the layout of the arc extinguishing grid sheets, a more effective arc extinguishing effect is realized.

The invention relates to the technical field of circuit breaker assembling and manufacturing, in particular to a primary and secondary fusion pole-mounted circuit breaker and assembling equipment thereof.The pole-mounted circuit breaker comprises a main body, the main body is composed of a mechanism box and an arc extinguish chamber, the arc extinguish chamber is movably connected to the top of the mechanism box in an inserted mode, and assembling is conducted in an inserted installation mode; the assembling equipment comprises a rack, a material frame and a conveying frame for installing a conveying belt, a clamping mechanism and a deviation rectifying mechanism are installed on the two sides of the conveying frame correspondingly, a reciprocating driving mechanism is arranged between the material frame and the conveying frame, and a clamping mechanism used for positioning the mechanism box is arranged on the outer side of the conveying frame; the outer side of the conveying frame is further provided with a jacking mechanism used for pulling the pull column outwards, steering of the clamped arc extinguish chamber is automatically completed through the reciprocating driving mechanism, and the reciprocating driving mechanism is matched with the clamping mechanism and the deviation rectifying mechanism to complete automatic clamping of the arc extinguish chamber to be installed and installation direction correction.

The invention provides a circuit breaker and power equipment. The circuit breaker comprises a shell, an operating handle, an operating mechanism, a through-flow assembly, an arc extinguishing chamber and an arc extinguishing module. And the operating handle, the operating mechanism, the through-flow assembly, the arc extinguishing chamber and the arc extinguishing module are sequentially arranged along the depth direction of the circuit breaker. The through-flow assembly comprises a moving contact assembly and a static contact. The operating mechanism is connected with the moving contact assembly. The operating handle is used for controlling the operating mechanism to drive the gas production connecting rod of the moving contact assembly to rotate, so that the moving contact is in contact with or separated from the static contact. The arc extinguish chamber is used for eliminating electric arcs generated when the moving contact is separated from the static contact. The arc extinguishing module is used for purifying gas sprayed out of the arc extinguishing chamber. All the mechanisms of the circuit breaker are arranged in the depth direction of the circuit breaker, the size in the height direction is small, and the number of circuit breakers capable of being arranged in a cabinet is increased. And when the moving contact is separated from the static contact, the gas production connecting rod is used for forming gas blowing, so that the arc passes through the arc extinguishing chamber along the depth direction to realize arc extinguishing, and the safety of the circuit breaker is improved.

The present application provides a circuit breaker and an electrical device. The circuit breaker comprises a housing, and an operating handle, an operating mechanism, a current-conducting assembly, and an arc extinguishing chamber which are sequentially provided in the housing along the depth direction of the circuit breaker. The operating mechanism comprises two mounting plates, a latch assembly, and at least one operating assembly. The operating assembly comprises a trip lever, an upper connecting rod, a lower connecting rod, and springs. Along the height direction of the circuit breaker, the latch assembly is located on one side of the rotating center of the trip lever, and the upper connecting rod and the lower connecting rod are located on the other side of the rotating center. Each mounting plate is provided with a limiting rod which is used for limiting rotation of the trip lever and the upper connecting rod when the latch assembly unlocks the trip lever. The upper connecting rod is provided with a limiting rod which is used for limiting the rotation angle of the trip lever during switching-on / switching-off. The mechanisms of the circuit breaker are provided along the depth direction, resulting in a smaller dimension along the height direction. In addition, the operating mechanism has a simple structure and allows for locking and unlocking, thereby facilitating the miniaturization of the circuit breaker, and thus allowing for an increased number of circuit breakers to be arranged within a cabinet.

The utility model discloses a high-voltage wire connector rapid switching circuit system based on a hot plug technology, which comprises a power supply module, a power supply switching module used for monitoring a power supply state of the power supply module and automatically changing a power supply mode, and a buffer module used for reducing switching influence, the power supply module is electrically connected with the power supply switching module and the buffer module; according to the utility model, the hot plug control circuit constructed by adopting a TPS2490 chip is matched with the slow start units R1-R6 and Q1-Q4 formed by connecting a plurality of MOS tubes in parallel and the hierarchical capacitor arrays C7-C12, so that dynamic impedance matching during plugging of the standby power supply is realized. The slope change of bus voltage is monitored in real time through the hot-plug voltage detection circuit, power supply switching over-transition is completed on the premise of keeping the continuity of load power, relay contacts are protected by arranging the buffer module, the switching efficiency is improved by reducing interference, and the reliability of power supply switching is improved. Compared with a traditional arc extinguishing mode, the switching influence can be reduced while the power is not influenced.

The invention discloses a circuit breaker device with a fireproof function and a method, and relates to the technical field of circuit breaker fire prevention. The device comprises an insulating shell and an insulating auxiliary shell, the insulating shell and the insulating auxiliary shell are the same in specification, the insulating auxiliary shell is fixedly installed on one side of the insulating shell, a circuit breaker assembly and an active circuit breaking protection assembly which are used for protecting a circuit are arranged in the insulating shell, and the two ends of the insulating shell are each provided with an auxiliary clamping assembly used for limiting a wire. According to the invention, through the arrangement of the active circuit break protection assembly and a dual circuit break mechanism of component conventional short circuit protection and active temperature linkage protection, when the conventional short circuit protection mechanism is not triggered due to a fault, the electromagnetic coil continuously bears large current to generate joule heat, and after the temperature sensor monitors a supercritical temperature, the electromagnetic coil is switched on; a temperature control signal is transmitted to the active circuit breaking protection assembly to trigger the active circuit breaking protection assembly depending on a miniature electric telescopic rod, a lifting block and other structures, a turnover block is driven to turn over, a circuit is forcibly broken, and fire hazards caused by heating due to faults are effectively avoided.

The invention discloses a breaking assembly, a circuit breaking device, a motor control system and a vehicle, relates to the technical field of vehicles, and aims at solving the problem that a traditional circuit breaking device is large in vibration. The disjunction assembly may include a housing and two disjunction members. A sliding cavity is formed in the shell, the two breaking pieces are contained in the sliding cavity in a sliding mode, a power device is arranged on the portion, located between the two breaking pieces, of the sliding cavity, the power device can push the two breaking pieces to move in the opposite directions, and each breaking piece is suitable for breaking the corresponding connecting conductor. The breaking assembly and the circuit breaking device provided by the invention are balanced in overall stress, small in generated vibration, and beneficial to stable operation of the circuit breaking device.

An arc-extinguishing mechanism that includes an arc-extinguishing chamber. The arc-extinguishing chamber includes two partition plates and a plurality of arc-extinguishing grids arranged between the two partition plates. An arc-striking sheet which cooperates with a moving contact or a static contact is arranged at the top of the arc-extinguishing grids. The arc-extinguishing mechanism further includes a first magnetizing mechanism that has two oppositely arranged first magnetizing sheets on two sides of the plurality of arc-extinguishing grids, and an arc-striking structure arranged at the bottom of the arc-extinguishing grids. The first magnetizing sheets are parallel to the partition plates. The first magnetizing sheets, the arc-striking structure and the arc-striking sheets form a first magnetic loop used for generating a pushing force in the direction of an exhaust port of the arc-extinguishing chamber to an electric arc entering the arc-extinguishing chamber.

The invention relates to the technical field of circuit breakers, and discloses a circuit breaker with a clapping type tripping assembly, which comprises a shell, an inner cavity of the shell is rotatably connected with an operating rod, a gas generation assembly is fixedly mounted at the bottom end of the inner cavity of the shell, and driving assemblies are arranged at the front end and the rear end of the operating rod. And a blowing assembly is fixedly mounted on the left side of the gas generation assembly. The gas box is arranged in the shell, when a circuit fault occurs, the operation rod rotates to drive the gear ring to rotate, then the first rack, the extension rod and the lifting plate are driven to move downwards, gas in the gas box is squeezed into the one-way gas outlet pipe, the gas is sprayed out upwards through the spray head, an arc is pushed by gas flow to quickly pass through the arc chute, and the arc extinguishing effect is achieved. And the arc extinguishing speed is improved.

The invention relates to a universal circuit breaker energy absorption device, and the device comprises a housing which is of a hollow structure; the moving contact mechanism comprises a supporting seat, and the lower end of the supporting seat is rotatably arranged at the bottom of the inner side of the shell; the energy absorption structure is made of a high-temperature-resistant viscoelastic material and is arranged at the front end of the inner side of the shell; when the universal circuit breaker is switched off, the supporting seat rotates around the rotating axis at the lower end to a switching-off position, the front end of the supporting seat is in collision contact with the energy absorption structure, the energy absorption structure is made of a high-temperature-resistant viscoelastic material, friction and lag deformation are generated after the energy absorption structure is stressed, kinetic energy is converted into heat energy, and the energy absorption structure is in contact with the energy absorption structure. The collision kinetic energy between the supporting seat and the inner side of the shell is reduced, so that the resilience force converted from the collision kinetic energy is reduced, the resilience distance is obviously reduced after the supporting seat collides with the shell, and the possibility of electric arc reignition is greatly reduced.

The utility model relates to a tripping mechanism and circuit breaker relates to electrical switch technical field. The tripping mechanism includes support, lock catch spare and jump catch spare, support, lock catch spare and jump catch spare set up in the casing of circuit breaker respectively, support is connected with casing, lock catch spare, jump catch spare and the movable contact of circuit breaker rotation respectively, lock catch spare is used for with jump catch spare buckle, jump catch spare is connected with the handle transmission of circuit breaker, handle is driven through support, lock catch spare and jump catch spare common cooperation drive movable contact and the static contact of circuit breaker and open or close gate, wherein, the connecting line direction of the rotation connection point of support and casing and the rotation connection point of jump catch spare and support is first direction, the connecting line direction of the rotation connection point of support and casing and the rotation connection point of movable contact and support is second direction, the included angle between first direction and second direction is less than 90 DEG. The circuit breaker includes above-mentioned tripping mechanism. The tripping mechanism and circuit breaker can solve the problem that the volume of traditional circuit breaker is bigger.

The invention relates to an N-pole module assembly of a circuit breaker and the circuit breaker. The N-pole module assembly of the circuit breaker comprises a main body function module and a current detection module, and further comprises a first N-pole conductive plate fixedly integrated on the main body function module and a second N-pole conductive plate fixedly integrated on the current detection module, and the main body function module and the current detection module are respectively two independent modular structures. And the first N-pole current-conducting plate and the second N-pole current-conducting plate are fixedly and electrically connected to form an N-pole electric loop. According to the invention, the complicated bending and wiring process of the soft wire in the N-pole module assembly in the prior art is avoided, the assembly is convenient, and the automatic assembly can be realized. Moreover, through the special arrangement of the relative positions of the N-pole electric loop and the L-pole electric loop, the Lorentz force generated by the magnetic field generated by the current on the N-pole electric loop on the electric arc in the circuit breaker unit can assist the electric arc to be further pushed and lengthened, and the effect of enhancing the magnetic quenching function can be achieved.

The circuit breaker comprises a shell, an operating mechanism, a traction rod, a protection mechanism, at least one rotating shaft system, and a static contact and an arc extinguish chamber which respectively correspond to the rotating shaft system, the protection mechanism comprises at least one air blowing mechanism, the rotating shaft system, the static contact and the arc extinguish chamber are arranged at intervals in the width direction of the circuit breaker, the operating mechanism is located above the rotating shaft system, the arc extinguish chamber is located above the static contact, and the arc extinguish chamber is located on one side of the operating mechanism in the length direction of the circuit breaker. The draw bar is rotatably arranged on the other side of the operating mechanism, the length direction of the air blowing mechanism is arranged along the length direction of the circuit breaker, one end of the air blowing mechanism in the length direction is located between two adjacent arc extinguish chambers, and the other end of the air blowing mechanism in the length direction is arranged opposite to the draw bar; the sliding direction of the push rod of the air blowing mechanism is arranged along the length of the circuit breaker. According to the circuit breaker, the overall layout of the circuit breaker is compact and reasonable, the air blowing mechanism is horizontally arranged in the circuit breaker, and the breaking capacity of the circuit breaker is improved.

An intelligent controller belongs to the technical field of low-voltage circuit breakers. Comprising a shell with an upper cover and a base, and further comprises an operation display circuit board and a main control circuit board which are sequentially stacked in the shell from top to bottom and electrically connected with each other, a first burning hole and a second burning hole corresponding to the burning socket are respectively formed in the upper cover and the operation display circuit board; and an external connector can be connected with the burning socket after sequentially penetrating through the first burning hole and the second burning hole. The intelligent controller has the advantages that the expandability and the expansion convenience of functions of the intelligent controller are improved, and the burning efficiency is improved.

The present invention relates to an arc extinguishing unit of a molded case circuit breaker and, more specifically to an arc extinguishing unit of a molded case circuit breaker, having improved arc elongation performance. The arc extinguishing unit of a molded case circuit breaker, according to one embodiment of the present invention, comprises: a first side plate and a second side plate arranged to be spaced a predetermined distance apart from each other; a plurality of grids arranged by predetermined intervals between the first side plate and the second side plate; and an insulation member arranged to adjoin each of the plurality of grids.

The arc extinguishing system comprises an arc extinguishing chamber matched with a contact system, the arc extinguishing chamber comprises two arc extinguishing cavities which are communicated with each other, each arc extinguishing cavity is internally provided with at least one grid plate group, the contact system comprises a moving contact assembly and a static contact assembly which are matched with each other, the two arc extinguishing cavities are arranged at an included angle, and the two arc extinguishing cavities are arranged at the included angle. The static contact assembly is arranged at the joint of the two arc extinguishing cavities, the static contact assembly comprises a static arc striking angle, the opening and closing track of the moving contact assembly and one end of the static arc striking angle correspond to an arc inlet of one arc extinguishing cavity, and the other end of the static arc striking angle extends to the other arc extinguishing cavity. And the grid plate groups in the two arc extinguishing cavities are joined at the joint of the two arc extinguishing cavities. According to the utility model, the two arc extinguishing cavities are arranged at the included angle, so that the arc extinguishing grid sheets are additionally arranged in the arc extinguishing chamber in different directions, the breaking performance of high voltage and large current can be considered, and when the arc extinguishing chamber is arranged in the circuit breaker, the arc extinguishing chamber can be enlarged as much as possible in a limited space.

An arc extinguish chamber belongs to the technical field of low-voltage apparatuses. Comprising a pair of side plates and a plurality of grid sheets arranged between the pair of side plates, and the grid sheets are arranged at intervals; the LED lamp is characterized by further comprising a pair of partition plates made of insulating materials without glass fibers, and each partition plate is attached to the inner side of one side plate. The grid plate has the advantages that the side plates are prevented from being burnt by electric arcs, particles cannot be generated after the partition plate is burnt, and normal work of the grid plate cannot be affected.

The utility model relates to the field of low-voltage electrical technology of an electric power system, in particular to a static contact assembly and a molded case circuit breaker, a static contact body is composed of an inverted Z-shaped connecting part and an inverted U-shaped contact part, a static contact is arranged on the top end face of the contact part, an arc striking sheet is connected to the lower surface of the static contact body, and the arc striking sheet is connected to the lower surface of the static contact body. The arc striking piece is located at the front end of the static contact and used for pointing to arc striking of an arc extinguish chamber, and the magnetic increasing pieces are connected to the contact part and located on the two sides of the upper portion of the static contact, so that magnetic field distribution is facilitated, the electric repulsive force of a moving contact conducting rod can be greatly increased, the molded case circuit breaker can act faster and more reliably when overload or short circuit or other abnormal conditions happen, and the service life of the molded case circuit breaker is prolonged. Therefore, a better protection effect is provided, the breaking capacity of the molded case circuit breaker is improved, the magnetic increasing sheet is sleeved with the insulating part, current between different potentials is effectively isolated, eddy current is inhibited, electric leakage or short circuit is prevented, the safety of the molded case circuit breaker is improved, and the service life of the contact is prolonged.

The utility model discloses a circuit breaker with a metal particle adsorption function. The circuit breaker mainly solves the problem that gas containing metal particles of a conventional circuit breaker is directly exhausted from an exhaust hole, and certain potential safety hazards exist. One end of the arc striking sheet is arranged on the front side of the arc extinguish chamber, the middle section of the arc striking sheet extends to pass through the outer side of the bottom of the arc extinguish chamber, the tail end of the arc striking sheet extends into the air outlet channel and is provided with a through groove (31), and the through groove is communicated with the air outlet hole and the exhaust hole. According to the circuit breaker with the metal particle adsorption function provided by the utility model, metal particles are discharged after being shielded and adsorbed by the arc striking sheet, so that the circuit breaker is safer to use.

The utility model discloses an overvoltage protection type ozone generator which comprises a generator body, a first sliding rail is fixedly connected to the surface of the inner bottom of a base at the bottom of the generator body, a first sliding block is slidably connected to the surface of the first sliding rail, and a conductive insertion rod and a cross rod are fixedly connected to the surfaces of the left side and the right side of the first sliding block respectively. The far end of the cross rod is fixedly connected with an iron block, and a metal rod wound with a power supply line is arranged on one horizontal side of the iron block; according to the utility model, through the arrangement of the metal rod wound with the power supply line, when the voltage is instantaneously and abnormally increased and the current is sharply increased, the magnetism of the two ends of the metal rod is improved, and the iron block is attracted to separate the conductive insertion rod from the conductive insertion tube, so that the circuit is disconnected, and the equipment damage caused by overlarge voltage is avoided; according to the device, the response time is greatly shortened, and the safety and the practicability are improved.

The purpose of the present invention is to obtain a circuit breaker that prevents swinging of a rail of a spring member, prevents winding of an arc and metal particles into the spring member, and obtains a stable biasing force generated by the spring member for pressing a movable contact toward a fixed contact. The present invention is provided with: a cross bar (30) having a wrist section (30e) and a bottom surface section (30d) having a gap (30c); a movable contact (9), one end of which is provided with a movable contact (8) that can be brought into contact with or separated from the fixed contact, and the other end of which is provided with a locking pin (31); a crimping spring (33), one end side of which is disposed between the bottom surface portion (30d) and the wrist portion (30e) of the cross bar (30) and the other end side of which is disposed on the locking pin (31) side, and which applies a rotational force to the movable contact (9), said rotational force pressing the movable contact (8) toward the fixed contact; and a spring support section (32) that engages with the locking pin (31) and has a spring support plate (32c) that supports the other end of the crimping spring (33). The spring supporting part (32) is provided with a lower plate (32a) rising from the spring supporting plate (32c), and the lower plate (32a) blocks the gap (30c) of the bottom surface part (30d) and holds the front end side of the lower plate (32a) on the bottom surface part (30d).

In a current-limiting contact unit added to a circuit breaker, contact welding is suppressed when the device returns from current-limiting interruption. [Solution] The air damper 25 delays the operation of the movable contact 23, which has been opened by flow limiting and blocking, when it is closed again by a compression spring 24, and comprises a cylinder 31 and a piston 32. The cylinder 31 extends in the direction in which the movable contact 23 moves linearly, and is formed in a cylindrical shape with one end closed and the other end open. The piston 32 extends in the direction in which the movable contact 23 moves linearly, is fixed to the movable contact 23, has its tip side fitted into the cylinder 31, and its base end side is biased in the forward direction by a compression spring 24.