Mitsubishi Denki Kabushiki Kaisha

Haruhisa Toda

Toshiyuki Tanibe

Hiroaki Fujihisa

Shiroo Murata

Hiroaki Fugihisa

Kazuhiro Ishii

Setsuo Hosogai

Shiro Murata

Kouhei Fujiwara

Yoshiaki Matsumoto

Kazumi Shioguchi

Junichi Kawakami

Takafumi Kondo

An overcurrent tripping device which is included in a circuit breaker is constituted by a pre-assembly unit of a holder with a conductor, a fixed core for generating a magnetic attraction force responding to an overcurrent, and a bimetal warping responding to the temperature rise of the conductor, and an operation arm rotatably borne on the holder and having a moving core which is to be attracted to the fixed core by the magnetic attraction force.

Circuit breaker with overcurrent tripping device

A circuit breaker wherein at least a pin sliding surface of a guide hole of a first contact arm, at least a pin sliding surface of a long hole of a second contact arm, and at least a contact surface of a second pin in contact with both the pin sliding surfaces, are treated by low-friction treatment to reduce frictional resistance, and surface-treated to provide surfaces exempt from attachment of molten metal caused by arcing; and furthermore at least the pin sliding surface of the first contact arm and at least the pin sliding surface of the long hole of the second contact arm are hardened to provide both the pin sliding surfaces with greater hardness than the second pin, thereby ensuring smooth movement of the second pin.

Circuit breaker with smooth sliding operation

A multipole circuit breaker of a type with a mechanism pole having a switching mechanism in which adjacent poles are disposed in opposition to the mechanism pole with an interphase wall therebetween and each having an internal attachment such as an alarm switch or the like but no switching mechanism. A latch engages a cradle of the switching mechanism and is arranged to be actuated by an automatic tripping device. A supporting shaft rotatably supports the latch, an a lever fixed on the supporting shaft engages the cradle. Actuators are fixed on the supporting shaft so as to engage the internal attachment of the respect adjacent poles. The supporting shaft is made of metal. Insulating caps are inserted and fixed onto end portions of the supporting shaft, the supporting shaft passing at portions of the insulating caps through the interphase walls. The actuators are inserted and fixed onto the insulating caps.

Multipole circuit breaker

In a trip relay mechanism (50) of circuit breaker wherein a latch (23A), a latch lever (25A) and a trip bar (34) are urged to engage with each other; the trip bar (34) is disposed between the latch (23A) and the latch lever (25A) in the direction of power source side-load side of the circuit breaker and they (23A, 25A, 34) are urged by one double-torsion spring (35), and further the trip bar (34) is separated into a main part (34B) extended over each pole and a latching part (34A) for engaging the latch lever (25A).

Circuit breaker

A circuit breaker has a stationary contact arm (2) having a stationary contact (3), a first contact arm (107) having a contact (6) for contacting the stationary contact (3) and an extended terminal portion (107) for connecting a flexible wire (8) and a second contact arm (110) for pivoting the first contact arm, and a third contact arm (110a) that pivots about a common axis of the second contact arm and is provided with a flattened U-shaped aperture (114) thereon, and which is connected with an oblong aperture of the second contact arm by a connecting member (16).

A multi-pole circuit interrupter having a first pole unit provided with an operating mechanism and a second pole unit provided with no operating mechanism for interrupting current flowing therethrough by separating a movable contact from a stationary contact as a result of an electromagnetic repulsive force generated upon occurrence of a large overcurrent irresepective of the automatic trip operation of an operating mechanism. Each of the pole units of the circuit interrupter comprises a contact arm assembly for supporting the movable contact including a first contact arm and a second contact arm pivotally supported by a common pivot pin. The first contact arm in the first pole unit has an elongated guide hole extending in a direction of movement of the movable contact and is directly connected to the operating mechanism. The first contact arm in the second pole unit is connected to the operating mechanism through a cross bar. The second contact arm has an elongated hole extending substantially in a direction of extension thereof. A spring-biased sliding pin extends through the elongated hole and the guide hole, and a stopper is mounted to a base of the second pole unit for limiting movement of the second contact arm beyond a predetermined position.

Multi-pole circuit interrupter

A circuit interrupter comprising an automatic trip unit connected to an interrupting unit for tripping the interrupting unit to open separable contacts in response to an overcurrent, the automatic trip unit being a replaceable unit selected from a plurality of differing types of trip units including an electronic trip unit and a thermally responsive electromagnetic trip unit.

Circuit interrupter

A multi-pole circuit interrupter comprising first and second pole units separated by a partition wall in a housing, each of the pole units having a pair of separable contacts. The contacts of the first and the second pole units are connected by a cross bar for simultaneous movement. An operating mechanism is disposed in the first pole unit for separating the contacts in response to an overcurrent flowing through the interrupter. An alarm switch is disposed in the second pole unit for indicating the tripping of the operating mechanism, and an actuator is disposed between the operating mechanism and the alarm switch for detecting the tripping of the operating mechanism and actuating the alarm switch. The actuator comprises a rotatable shaft supported in the housing and extending through the partition wall including a substantially circular opening having a diameter slightly larger than that of the rotatable shaft, an actuator arm secured to one end of the rotatable shaft for movement caused by the tripping action of the operating mechanism, and an actuator level secured to the other end of the rotatable shaft for engaging and actuating the alarm switch.

A multi-pole circuit interrupter having a first pole unit provided with an operating mechanism and a second pole unit provided with no operating mechanism. Each of the pole units comprises a movable contact, a stationary contact, and a contact arm assembly for supporting the movable contact of the respective pole unit including a first contact arm and a second contact arm pivotally supported by a common pin. The first contact arm in the first pole unit have an elongated guide hole extending in a direction of movement of the movable contact and is directly connected to the operating mechanism. The second contact arm has an elongated hole extending substantially in a longitudinal direction thereof. A spring-biased sliding pin extends through the elongated hole and the guide hole. The guide hole of the second pole unit extends further upwards than the guide hole of the first pole unit so that the sliding pin in the first pole unit starts to slide along the pin braking surface of the guide hole only after the sliding pin in the second pole unit has left the pin breaking surface and moves on the pin sliding surface. As a result, a time delay between the resetting movements of the sliding pin along the pin braking surface of the guide hole in the first and second pole units is provided.

A circuit interrupter comprises a contact arm assembly for supporting the movable contact composed of a first contact arm and a second contact arm pivotally supported by a common pin, the first contact arm having an elongated guide hole extending in the direction of movement of the movable contact, the second contact arm having an elongated hole extending substantially in the direction of extension of the second contact arm. A second pin extends through the elongated hole and the guide hole, and a spring is provided for biasing the second pin. The elongated hole has a pin sliding surface on which the second pin slides and which forms an angle of 90.degree. or more with respect to a pin sliding surface of the elongated pin guide hole when the first contact arm is being reset after the second contact arm is separated by an electromagnetic repulsive force.

An automatic trip device for a circuit breaker includes a U-shaped stationary iron core disposed around a current-carrying conductor. The stationary core includes a semicircular recess on one leg thereof having V-shaped bearing surfaces formed at each end of the recess. A movable iron core is positioned across the legs of the stationary core and includes semicircular projection fitted into the recess of the stationary core. A shaft extends through the projection and pivots at each end in one of the V-shaped bearing surfaces. Tension springs connected between the stationary core and one end of the movable core produce opening rotational bias on the movable core. Electromagnetic force produced by an over-current flow through the conductor causes closing rotational movement of the movable core. The disclosed construction results in elimination of undesireable sound vibrations produced in prior art devices under conditions of current flow below overload level.

Growing community of inventors

Fukuyama, Japan

Haruhisa Toda