Abstract: An alarm output device is capable of outputting a mechanical alarm signal to attached alarm switches in linkage with a tripping operation of a circuit breaker. The alarm output device includes an alarm output plate provided on an outer lateral surface of a frame of an opening/closing mechanical unit and is operable in linkage with a latch of the opening/closing mechanical unit, so that a movement of the alarm output plate is transmitted to the attached alarm switches to perform a switching operation. The alarm output plate is provided with a pair of operation terminal members corresponding to an internal alarm switch and an external alarm switch of the circuit breaker.

Abstract: An external auxiliary switching unit includes a unit case, an auxiliary contact mechanism having contacts to be opened and closed in response to on/off operations of a circuit breaker, and an alarm contact mechanism operating in response to a tripping operation of the circuit breaker. An operating arm extends from a contact holder of the alarm contact mechanism and protrudes sideward from the unit case. The operating arm is inserted into a breaker housing when the auxiliary switching unit is mounted onto the circuit breaker. When the alarm output plate rotates upon tripping of the circuit breaker, the alarm output plate is released from the operating arm to detect the tripping and output an alarm signal. After the tripping, the circuit breaker is reset to cause the alarm contact mechanism to return to the non-detecting position via the alarm output plate, thereby stopping the alarm signal.

Abstract: A circuit breaker for opening and closing a main-circuit includes main-circuit contacts; an opening-and-closing mechanism having a switching lever for opening and closing the main-circuit contacts, a main spring for urging the switching lever, and a toggle-link mechanism attached to the switching lever; and an operational handle. The operational handle includes a locker handle rotatably supported on a handle pin and connected to the toggle link of the switching mechanism, and a pushbutton linked to the handle. When the pushbutton is pushed, the handle portion rotates to allow the switching lever to close the main-circuit contacts.

Abstract: A circuit breaker for opening and closing a main-circuit includes main-circuit contacts; an opening-and-closing mechanism having a switching lever for opening and closing the main-circuit contacts, a main spring for urging the switching lever, and a toggle-link mechanism attached to the switching lever; and an operational handle. The operational handle includes a locker handle rotatably supported on a handle pin and connected to the toggle link of the switching mechanism, and a pushbutton linked to the handle. When the pushbutton is pushed, the handle portion rotates to allow the switching lever to close the main-circuit contacts.

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: 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 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: 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: 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 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: A handle-operating mechanism is used for a circuit breaker. The mechanism includes a rotary operating handle operated to open and close a main-circuit contact of a circuit breaker, a rotating gear connected to the operating handle, and a contact opening-and-closing mechanism having a toggle gear meshing with the rotating gear. The contact opening-and-closing mechanism is linked to the operating handle through the rotating gear and the toggle gear. A clutch gear is interposed between the operating handle and the rotating gear to provide an idle stroke. Thus, when the circuit breaker is turned on, the operating handle runs idly after the rotation of the operating handle has been started and before the rotating gear drives the toggle gear.