Abstract: [Problem] To more smoothly commence actuation of a stroke simulation function. [Means for Resolution] A pedal feel simulator unit 3 of a master cylinder 1 has a start-up load reducing unit 28, and this start-up load reducing unit 28 has a start-up load reducing spring 29. The elastic modulus of the start-up load reducing spring 29 is set smaller than the elastic modulus of a simulator actuation piston return spring 16. Consequently, when the start-up load reducing spring 29 is pressed by an input shaft 4, the start-up load reducing spring 29 starts to elastically flex before the simulator actuation piston return spring 16 elastically flexes and a simulator actuation piston 14 starts to move forward. Because of this, the start-up load of the pedal feel simulator unit 3 is reduced.

Abstract: An overload tripping device includes a temperature-compensating bimetal operating as a tripping lever and interposed between an output lever of a differential shifter mechanism linked with a main bimetal and a latch receiver of an opening-and-closing mechanism section of a circuit breaker. The temperature-compensating bimetal has an intermediate portion journaled on a bimetal holder. An operating arm made of a light molding material is attached to a tip of the temperature-compensating bimetal so as to push the latch receiver. Additionally, a balance weight may be installed on the temperature-compensating bimetal to balance inertial moments on the opposite sides of the bimetal. Thus, the circuit breaker is prevented from being inadvertently tripped due to external stimulus.

Abstract: A breaking mechanism includes a latch receiver engaging a latch to allow a movable contact shoe to be closed, and a tripping device for rotationally driving the latch receiver to disengage the latch to open the movable contact shoe. An engaging surface of the latch engaging the latch receiver is formed as a projecting circular surface, whereas an engaging surface of the latch receiver engaging the projecting circular surface is formed as a recessed circular surface having a radius of curvature greater than that of the projecting circular surface. The center of the curvature of the recessed circular surface coincides with the axis of a support shaft supporting the latch receiver. The loads causing a tripping device to drive the latch receiver do not change even if the location of an engaging point is changed.

Abstract: In a slow-make type circuit breaker for opening and closing a main circuit contact in synchronism with the manual operation of a rotary operation handle, a ratchet unit 12 as an artificial quick-make means for forcibly increasing the operating force of the operation handle in the middle of a stroke for ON operation of the contact is constituted by a convex cam 11 made of metal and coupled with the operation handle 5, a ratchet 12b made of metal and disposed at a point close to an ON position of the operation handle so as to face the cam, a driving spring 12c for pressing the ratchet toward a rotary movement path of the cam, and a ratchet case 12a in which these parts are incorporated. The unit is fabricated inside a cover 1b of a circuit breaker body. Here, the cam and the ratchet are formed as common parts, and the driving spring is selected in accordance with the kind of circuit breaker.

Abstract: A circuit breaker is formed of a main body case made of resin and divided into a lower case, an upper cover, and an intermediate case, into which parts of the circuit breaker are integrated. The intermediate case has pocket shaped sockets formed on a top surface side thereof, into which the tips of the interphase partition walls provided in the upper cover are fitted. Also, the intermediate case has recessed grooves formed on a bottom surface side thereof to fit over upper edges of the interphase partition walls provided in the lower case. Thus, the circuit breaker can be assembled easily and becomes more rigid.

Abstract: A mounting structure for mounting a switch device includes a main body case for the switch device having slots formed in lower portions of the front and rear surfaces, and mounting plates to be inserted into the slots. Each mounting plate has a screw hole at one end and an insertion portion at the other end The insertion portions are inserted into the slots to allow the main body case to be fixed by the mounting plates. The switch can be mounted using screws inserted into the screw holes in the mounting plates.

Abstract: A current-interrupting section of a molded case circuit breaker includes fixed contact shoes and a rotary bridge-type contact shoe held in a contact shoe holder. A pair of pressure springs is assembled in the contact shoe holder to press the rotary contact shoe to the fixed contact shoes. The pressure spring is torsion coil springs and have U-shaped offset arm portion drawn out from the center of the coil. A pair of the torsion coil springs is arranged above and under the rotary contact shoe. Furthermore, legs of the torsion coil springs at ends are hooked to sidewalls of the contact shoe holder. The offset arm portions at the center of the torsion coil springs engage the rotary contact shoe at positions symmetrical with respect to the rotational center of the rotary contact shoe.

Abstract: In a circuit breaker, a rotary-operating handle is linked with an opening and closing mechanism via a driving gear so that main circuit contacts can be opened and closed by rotating an opening and closing lever. A vertically moving handle lock lever is arranged between a tip of the opening and closing lever and the driving gear directly coupled to the operating handle, so that when the main circuit contacts are opened after being welded, the lock lever abuts against the driving gear to restrain the operating handle to the vicinity of the ON position, thereby restricting the movement to a contact-open indicating position. Further, an upward-inclined surface is formed in a stopper section located at a tip of the lock lever, so that if the contact welding is not severe, the lock lever can be pushed down to forcibly open the contacts.

Abstract: A circuit breaker is formed of a main body case made of resin and divided into a lower case, an upper cover, and an intermediate case, into which parts of the circuit breaker are integrated. The intermediate case has pocket shaped sockets formed on a top surface side thereof, into which the tips of the interphase partition walls provided in the upper cover are fitted. Also, the intermediate case has recessed grooves formed on a bottom surface side thereof to fit over upper edges of the interphase partition walls provided in the lower case. Thus, the circuit breaker can be assembled easily and becomes more rigid.

Abstract: In relation to a circuit breaker, a left-side accessory switch storage section and a right-side accessory switch storage section are provided in a breaker case 1. A contact point of an ancillary switch 7 provided in one of the accessory switch storage sections is opened or closed in conjunction with an output protrusion 6a formed on an open-close lever 6 of an open-close mechanism section 3 on the main unit. A contact point of an alarm switch 9 provided in the remaining accessory switch storage section is opened or closed in conjunction with an alarm output plate 8 which operates in association with tripping action of the breaker. The output protrusion 6a is caused to oppose an operation lever 7a of an ancillary switch which is formed into a symmetrical bifurcated shape and which is provided in the accessory switch storage section. The alarm output plate constitutes a pivotal lever coupled to a toggle shaft 3a of the open-close mechanism section.

Abstract: A circuit breaker includes an opening and closing mechanism section with an opening and closing lever, and an alarm-outputting plate operating in response to a tripping operation. A case for the circuit breaker has a plurality of switch housing sections formed on a top side thereof, in which are installed an auxiliary switch for detecting an ON/OFF state of a main circuit contact and/or an alarm switch for detecting a tripping operation. The opening and closing lever and the alarm-outputting plate have outputting projecting pieces, respectively, laterally spaced apart from each other corresponding to the respective housing sections, for transmitting mechanical output signals to the switches. When the auxiliary and alarm switches are installed, the auxiliary switch is linked to the outputting projecting piece of the opening and closing lever, while the alarm switch is linked to the outputting projecting piece of the alarm-outputting plate.

Abstract: A handle-operating mechanism for a circuit breaker includes a rotary operating handle for opening and closing a main-circuit contact of a circuit breaker, a rotating gear operably connected to the operating handle and having a first engaging device, and a contact opening-and-closing mechanism having a toggle gear meshing with the rotating gear. A clutch gear is connected to the operating handle to be interposed between the operating handle and the rotating gear, and has a second engaging device. An idle stroke is formed such that when the circuit breaker is turned on, the operating handle runs idly after rotation of the operating handle has been started and before the second engaging device engages the first engaging device to drive the rotating gear for actuating the toggle gear.

Abstract: A thermal overload open-phase tripping device includes in a case bimetals corresponding to different phases; a differential shifter mechanism composed of a push shifter and a pull shifter, linked to operating ends of the bimetals, and an interlocking plate; and a compensating bimetal for transmitting output from the shifter mechanism to an opening and closing mechanism section of a breaker main body. The push and pull shifters are slidably supported to extend over interphase partition walls in the case, and a case cover is placed and held over the push and pull shifters. Rib-shaped projections projecting from an inner surface of the case cover and facing the top surfaces of the shifters are provided as shifter position guides to constrain inclination of the shifters moving in accordance with bending displacement of the bimetals to hold the shifters horizontally.

Abstract: A molded case circuit breaker includes a switching mechanism and a current-interrupting section. The current-interrupting section is composed of an insulated case, fixed contact shoes arranged diagonally opposite to each other, a bridging rotary contact shoe, a contact shoe holder, and arc extinguishing devices. The fixed contact shoes are composed of linear contact shoe conductors to reduce a height of the section, and the fixed contact shoes are arranged vertically in parallel and opposite each other so that the fixed contact shoes and the rotary contact shoe form a Z-shaped conducting path.

Abstract: A current-interrupting section of a molded case circuit breaker includes fixed contact shoes and a rotary bridge-type contact shoe held in a contact shoe holder. A pair of pressure springs is assembled in the contact shoe holder to press the rotary contact shoe to the fixed contact shoes. The pressure spring is torsion coil springs and have U-shaped offset arm portion drawn out from the center of the coil. A pair of the torsion coil springs is arranged above and under the rotary contact shoe. Furthermore, legs of the torsion coil springs at ends are hooked to sidewalls of the contact shoe holder. The offset arm portions at the center of the torsion coil springs engage the rotary contact shoe at positions symmetrical with respect to the rotational center of the rotary contact shoe.

Abstract: A circuit breaker mechanism includes an operating part and an on-off switch part. The operating part includes a handle, a shaft, and a mechanism member. The handle is engages the shaft for rotation. The mechanism member moves responsively to rotation of the handle. The on-off switch part includes a switch lever, a switch shaft, and a spring. The switch lever is supported for rotation by the switch shaft between on and off positions. The spring biases the switch lever to one of the positions. The mechanism member has a portion engagable with a portion of the switch lever to control movement of the switch lever. The portions of the mechanism member and the switch lever are configured to permit assembly of the on-off switch part separate from the assembly of the operating part and engagement of the portions of the mechanism member and the switch lever subsequent to assembly of the on-off switch part.

Abstract: A molded case circuit breaker includes a switching mechanism and a current-interrupting section. The current-interrupting section is composed of an insulated case, fixed contact shoes arranged diagonally opposite to each other, a bridging rotary contact shoe, a contact shoe holder, and arc extinguishing devices. The fixed contact shoes are composed of linear contact shoe conductors to reduce a height of the section, and the fixed contact shoes are arranged vertically in parallel and opposite each other so that the fixed contact shoes and the rotary contact shoe form a Z-shaped conducting path.

Abstract: A circuit breaker includes main circuit contact shoes disposed in a circuit breaker case and urged by a contact spring, a contact opening and closing mechanism located above the contact shoes and including an opening and closing lever, a toggle link, an opening and closing handle and a latch, and an overcurrent tripping device located above the contact shoes. The toggle link includes a first link extending between the opening and closing lever and a toggle shaft located above, and a second link extending between the toggle shaft and the latch to overlap the first link in the V-form, and an opening and closing spring extends between the toggle shaft and a tip of a handle lever coupled to the opening and closing handle to extend downward. As a result, a space occupied by the contact opening and closing mechanism section in the height direction can be reduced to make the circuit breaker more compact.

Abstract: In a circuit breaker, bag-like insulating covers 15 are formed integrally with each holder support 14. The holder support 14 is combined with a movable contact holder 13 for holding a movable contact 4, so as to press and retain the movable contact 4 by a contact spring 5. A pair of leg portions of a magnetic drive yoke 6 are inserted into each of the insulating covers 15. Thus, the magnetic drive yokes 6 are covered with the insulating covers 15 so that there is no risk of an interphase short-circuit. In addition, the magnetic drive yokes 6 are unitized with a movable contact mechanism so that the work of assembling the circuit breaker becomes easy.

Abstract: A mounting structure for mounting a switch device includes a main body case for the switch device having slots formed in lower portions of the front and rear surfaces, and mounting plates to be inserted into the slots. Each mounting plate has a screw hole at one end and an insertion portion at the other end thereof. The insertion portions are inserted into the slots to thereby allow the main body case to be fixed by the mounting plates. The switch can be mounted using screws inserted into the screw holes in the mounting plates.