Electricity: electrothermally or thermally actuated switches – Thermally actuated switches – With fusible – combustible or explosive material
Reexamination Certificate
1999-02-11
2001-04-24
Picard, Leo P. (Department: 2835)
Electricity: electrothermally or thermally actuated switches
Thermally actuated switches
With fusible, combustible or explosive material
C337S157000, C337S403000, C361S115000, C180S279000, C200S061080
Reexamination Certificate
active
06222439
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a circuit breaking device incorporated into an automobile and others.
2. Description of the Related Art
Concerning this type circuit breaking device, it is common to use a fuse or a fusible link incorporated into an electric circuit so that the current flow in the circuit is interrupted when excessive current is generated in the electric circuit. On the other hand, in case of an emergency such as an automobile accident, it is necessary to forcibly shut off the electric circuit in a moment. For example, in an electric power supply circuit of an electric automobile which has come into wide use recently, there is a strong demand for forcibly shutting off the electric circuit in a moment in case of emergency.
As disclosed in Japanese Examined Patent Publication No. 58-47809, the conventional circuit breaker of this type is activated in such a manner that an electric conductor incorporated into an electric circuit is forcibly broken by an explosive force. As shown in
FIG. 10
, this circuit breaker is composed as follows:
In a reinforced glass case
105
, there are provided a fuse
102
connected between output terminals
101
, an explosive
103
, and a filament
104
for heating this explosive
103
. When an electric current generates in the input terminals
106
, this filament
104
is heated, so that explosive
103
is exploded. Utilizing the explosive force, the fuse
102
is broken. Due to the above structure, it is possible to forcibly shut off the electric circuit at an arbitrary time.
However, according to the conventional circuit breaker, the following problems may be encountered. The explosive force of explosive is dispersed in all directions, and only one portion of the explosive force acts on the fuse
102
. Therefore, a considerably high intensity of explosive force is required for breaking the fuse
102
positively. Therefore, the sealed glass case
105
must have a strong structure so that it can withstand a high intensity of explosive force. Further the sealed glass case
105
must be subjected to a special treatment for enhancing the mechanical strength. Accordingly, the manufacturing cost is inevitably increased. Additionally, the conventional circuit breaker is disadvantageous in that it is not simple to reset the circuit breaker after the fuse
102
has been broken. Thus, after an electric automobile has been involved in an accident, it is impossible to reset the circuit breaker immediately so that the electric automobile can be moved under its own power.
SUMMARY OF THE INVENTION
A circuit breaking device of the present invention has been accomplished in the above circumstances. It is an object of the present invention to provide a circuit breaking device by which the circuit can be positively shut off in case of emergency while an intensity of explosive force is being suppressed. Additionally, it is an object of the present invention to provide a circuit breaking device that can be reset easily for electric connection of the circuit if necessary after an electric conductor in the circuit has been broken.
As means for achieving the above object, according to a first aspect of the present invention, there is a feature that a circuit breaking device comprises a housing for accommodating an explosive exploding in response to a trigger signal, the housing having an opening for directing an explosive force in one direction, and an electric conductor to be broken by the explosive force of the explosive, the electric conductor provided on the way of a circuit, wherein the electric conductor is provided opposed to the opening, and an easy broken portion for facilitating a breaking of the electric conductor is formed on the electric conductor.
When the explosive is exploded in response to a trigger signal, its explosive force is directed to the opening of the housing, and the electric conductor provided at a position opposed to the opening receives the explosive force. Due to the foregoing, the easy broken portion is broken and the electric circuit is shut off.
The explosive force of explosive is directed to one direction, and the electric conductor is provided at a position where the explosive force can be effectively received, and further the easy broken portion is provided in the electric conductor so that the breaking of the electric conductor can be facilitated. Accordingly, even if an intensity of the explosive force is low, the electric conductor can be positively broken.
According to a second aspect of the present invention, there is a feature that, in the circuit breaking device according to a first aspect of the present invention, the easy broken portion is formed by cutting out the electric conductor so that a thickness can be thinned.
Since the electric conductor is cut out so that the thickness can be thinned in the cutout portion, it can be easily broken.
According to a third aspect of the present invention, there is a feature that, in the circuit breaking device according to a first aspect of the present invention, a cutout portion for facilitating a broken piece to be opened when the electric conductor is broken at the easy broken portion is provided on a side of the easy broken portion of the electric conductor.
The easy broken portion of the electric conductor is broken by the explosive force of explosive. At the same time, the broken pieces are opened while they are bent at the cutout portions. Therefore, the broken pieces of the broken portion are positively prevented from coming into contact with each other after the electric conductor has been broken.
According to a fourth aspect of the present invention, there is a feature that, in the circuit breaking device according to a first aspect of the present invention, a restricting wall for restricting a movement of the housing is provided on one side of the opening is formed and opposite side of the opening is formed.
When the explosive has exploded, the housing is prevented from retracting by the restricting wall. Therefore, the explosive force is intensely collected in the opening.
According to a fifth aspect of the present invention, there is a feature that, in the circuit breaking device according to a first aspect of the present invention, the device further comprises a resetting electric conductor by which both sides of a broken portion of the electric conductor can be reconnected to each other after the electric conductor has been broken.
After the electric conductor has been broken and the flow of current in the circuit has been interrupted, the resetting electric conductor is connected to both sides of the broken portion of the electric conductor. Thus, the circuit can be electrically connected again.
According to a sixth aspect of the present invention, there is a feature that, in the circuit breaking device according to a fifth aspect of the present invention, a lid is attached to a case, the resetting electric conductor is provided on the lid, the resetting electric conductor is not contacted with the electric conductor in the case when the lid is normally attached to the case, and the resetting electric conductor is contacted with both sides of the broken portion of the electric conductor when the lid is shifted from a normal position.
In the normal operating condition, the resetting electric conductor is not contacted with the electric conductor. Therefore, when the electric conductor is broken by an explosive force, the circuit is shut off. After that, when the lid-is shifted and the resetting electric conductor is connected to both sides of the broken portion of the electric conductor, the circuit is electrically connected again. Since the resetting electric conductor is provided on the lid, it is easy to handle it.
According to a seventh aspect of the present invention, there is a feature that, in the circuit breaking device according to a sixth aspect of the present invention, the case is provided with a display section for displaying a resetting state of the device for electrical connection at a po
Matsumaru Akio
Miyazaki Yoshiyuki
Tanigawa Mitsuru
Oliff & Berridg,e PLC
Picard Leo P.
Sumitomo Wiring Systems Ltd.
Vortman Anatoly
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