The present invention relates to a power breaker for interrupting a power circuit utilizing sublimation of a gas starting agent for example, and more particularly, to a resettable power breaker in which after a power circuit is forcibly interrupted when abnormal conditions were encountered or a short circuit, collision of vehicle or the like occurred, it is possible to reliably prevent the power circuit from being energized again by impact, vibration or other external force.
Japanese Patent Application Laid-open No. H11-301376 discloses a structure in which in a power breaker in which can forcibly interrupt a power circuit when abnormal conditions were encountered or a short circuit, collision of vehicle or the like occurred. However, a structure of the above-described conventional power breaker as the following problem. That is, since there is no function for holding the shaft at the interruption position after the shaft was slid to the interruption position to interrupt between the terminals, there is an adverse possibility that the shaft may be returned to the initial position by reaction force, impact, vibration caused by the projecting motion of the shaft or by external force, and the terminals may be electrically connected to each other.
Japanese Patent Application Laid-open No. H9-251830 discloses a structure in which in a power breaker having two terminals for making and breaking a power circuit and capable of connecting and separating the two terminals to and from each other by sliding movement of a shaft. In the case of a returning motion-preventing lock used in the disclosed technique, there is a problem that although the shaft can be locked at the interruption position, this lock can not be released to return the shaft to the initial position.
In view of the above circumstances, it is an object of the present invention to provide a resettable power breaker in which after a power circuit is forcibly interrupted when abnormal conditions were encountered or a short circuit, collision of vehicle or the like occurred, it is possible to reliably prevent the power circuit from being energized again by impact, vibration or other external force.
To achieve the above object, according to a first aspect of the present invention, there is provided a power breaker comprising a pair of terminals inserted in a power circuit for connecting a battery of a vehicle and loads provided in various portions of the vehicle, and a shaft capable of connecting and separating the terminals to and from each other by sliding movement of the shaft, in which the shaft is slid from an initial position where the terminals are connected to each other to an interruption position where the terminals are separated from each other, thereby interrupting the power circuit, wherein the shaft is provided at its one end with a returning motion-preventing lock which jumps out from the shaft when the shaft interrupts the power circuit to prevent the shaft from returning to the initial position.
According to the first aspect, the shaft capable of connecting and separating the two terminals with and from each other to energize and interrupt the power circuit is provided at its one end with a returning motion-preventing lock which jumps out from the shaft when the shaft interrupts the power circuit to prevent the shaft from returning to the initial position. Therefore, the shaft can be held at, the interruption position by the returning motion-preventing lock, and it is possible to reliably prevent the power circuit from being energized again by impact, vibration or other external force after a power circuit is forcibly interrupted when abnormal conditions were encountered or a short circuit, collision of vehicle or the like occurred.
Accordingly, since the returning motion-preventing lock jumps out from the shaft when the shaft interrupts the power circuit, a reset operation for returning the shaft to its original initial position can be carried out easily.
In a second aspect of the present invention, the returning motion-preventing lock is accommodated in a reset knob mounted to one end of the shaft together with a resilient member, and the returning motion-preventing lock jumps out by a force of the resilient member when the shaft interrupts the power circuit.
According to the second aspect, since the returning motion-preventing lock can easily be accommodated in the reset knob manually, the reset operation for returning the shaft to the original initial position can be carried out easily.
In a third aspect of the present invention, the resilient member is a torsion spring provided in the reset knob and acting around the reset knob fulcrum.
According to the third aspect, since the torsion spring exerts a force in an opening direction to the returning motion-preventing lock around the reset knob. Further, since the returning motion-preventing lock can easily be accommodated in the reset knob manually, the reset operation for returning the shaft to the original initial position can be carried out easily.
In a fourth aspect of the present invention, the returning motion-preventing lock is provided with a claw engaged with an apparatus body when the returning motion-preventing lock jumps out from the shaft, thereby preventing the shaft from falling out from the apparatus body.
According to the fourth aspect, the returning motion-preventing lock is provided with a claw engaged with an apparatus body when the returning motion-preventing lock jumps out from the shaft, thereby preventing the shaft from falling out from the apparatus body. Therefore, the reset operation for returning the shaft to the original initial position is not interrupted.