WO2000074096A1

WO2000074096A1 - A device for protecting a vehicle against fire

Info

Publication number: WO2000074096A1
Application number: PCT/SE2000/001094
Authority: WO
Inventors: Jan Ruus
Original assignee: Cassiopeja Ab
Priority date: 1999-05-26
Filing date: 2000-05-26
Publication date: 2000-12-07
Also published as: SE9901932D0; AU5120600A

Abstract

A device for protecting a vehicle in collisions comprises an interruption mechanism (1) connected to a pole (3) of the starter battery of the vehicle. The interruption mechanism contains a detonator (25) that is connected to a detector, so that for a heavy blow to the vehicle such as in a collision the detonator is made to detonate and thereby interrupt the electrical connections of the battery with other portions of electrical system of the vehicle so that they do not any longer obtain any power supply. Then also simultaneously the electrical connection between the generator of the vehicle and the electrically driven devices of the vehicle is broken. The interruption is produced by the fact that the detonation of the explosive cap drives a projectile (29) through the thin centre portion of an electrically conducting yoke (7). For example, after the interrupt no longer sparks can be produced due to electrically conducting parts of the vehicle and furthermore the operation of vital electrical devices such as a fuel pump is shut off so that fuel will not continue to be pumped. Thereby damages produced in the collision can be maintained at a minimum.

Description

A DEVICE FOR PROTECTING A VEHICLE AGAINST FIRE

TECHNICAL FIELD

The invention relates to a device tor protecting against fire which can arise in motor vehicles and also to a method ot such protection

BACKGROUND OF THE INVENTION

Fires in motor vehicles can occur when sparks ignite inflammable motor fuel. Sparks can be produced by electrical discharges caused by the electrical system of the vehicle and furthermore overheating can occur at short circuits For damage made to a vehicle so that the fuel escapes the electrical system can still be substantially intact and continue to pump for example fuel to the motor It has previously being proposed that for a damage to the vehicle such as in a collision the electrical current connection between the battery of the vehicle and other electrical devices in the vehicle is interrupted by making a detonator detonate thereby activating a circuit breaker see the German published Patent applications 44 02 994 and 44 30 284 and the German utihrv model 296 14 976

SUMMARY OF THE INVENTION

It is an object ot the present invention to provide a device and a method for protecting motor vehicles which can contribute to reducing the risk of fire in a collision between the vehicle and other objects For a damage to a vehicle such as in a collision, according to the art cited above, a fuse can be connected which for a command from some security system in the vehicle interrupts the current supply from the battery of the vehicle to the various electrical devices in the vehicle The devices comprise for for example motor vehicles also the electrical generator of the vehicle that in a collision can continue to generate current to the other electrical devices tor example a fuel pump This tact produces a risk of fire in spite of the interrupt at the battery In order to reduce this risk it is proposed that a security device is used that has three terminals between which the electrical connection is interrupted in a danger situation, as controlled by a suitable detector in the vehicle

Generally then, a device tor protecting a motor vehicle comprises an interruption mechanism connected to a pole ot a staπer battery of the vehicle The interruption mechanism contains a detonator that is mounted so that for a strong blow to the vehicle such as in a collision the detonator is ignited and thereby the electrical connection of the battery with the other pans of the electrical system of the vehicle is interrupted so that they no longer obtain any electrical current supply, in particular so that the connection line from one of the poles of the battery is interrupted The interruption mechamsm comprises an electrically conducting metal part such as a yoke which in turn has a thin centre portion agamst which the detonator acts when triggered On the metal part a prolongation piece having a pole shoe can be mounted which in a simple way can be mounted directly on a pole ot the battery The yoke is designed to have three terminals or arms, one of which is electrically connected to a pole of the battery, one to an electrical generator of the vehicle and one to electrically driven devices of the vehicle. In an advantageous embodiment the yoke has the shape of a plate provided with cutouts or recesses extending from the edges of the plate towards the centre portion thereof, where 5 an intermediate portion of the plate is left and holds the plate together. The detonator then acts against this intermediate portion which can be thinner than the remaining portion of the plate to facilitate that an interrupt is obtained between the portions of the plate between the recesses. These portions are the arms of the yoke and carry the electrical terminals. 0 A corresponding method likewise generally comprises that in order to protect a motor vehicle in collisions and similar strong blows to the vehicle the connection between the starter battery and other parts of the electrical system of the vehicle is interrupted so that they do not any longer obtain any electrical current supply and furthermore also preferably the electrical connection between the generator and the electrically driven s devices in the vehicle. It reduces the risk of igniting the generally easily flammable fuel of the motor vehicle, since the risk of sparks and hot points at electrical short circuits is reduced at the same time as all vital devices of the vehicle are brought out of operation. For example a fuel pump can not any longer continue to pump the fuel out of a broken conduit. The interrupt can be simply produced in the same way as when triggering o inflatable collision cushions or safety belt tensioners by detonating an explosive charge connected to a collision detector that is rigidly attached to the vehicle and that thereby can detect strong blows to the body or frame of the vehicle. In particular, in the interruption also the connection between a generator of the vehicle and electrical devices mounted in the vehicle and driven by electrical current are to be interrupted. ₅ BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described by way of a non-limiting embodiment with reference to the accompanying drawings in which:

- Fig. 1 is a view from above of an interruption mechanism for the electrical current supply of a vehicle, 0 - Fig. 2 is a view from the side of the interruption mechanism in Fig. 1 ,

- Fig. 3 is a partial sectional view taken through the axis of the interruption mechanism in Fig. 1,

- Fig. 4 is a sectional view of a projectile in a special embodiment,

- Fig. 5 is a partial sectional view through the axis of the interruption mechanism 5 showing a separate knife.

DESCRIPTION OF A PREFERRED EMBODIMENT

In Figs. 1 and 2 an interruption mechanism 1 for cutting off the electrical current supply in a vehicle, in particular a motor vehicle, in a collision is illustrated. A positive external pole 3 of an electrical battery or electrical accumulator such as of type lead acid battery that can be typically intended to drive the starter motor of the vehicle, is through an electrically conducting bridge part 5 electrically connected to an arm of a three-armed yoke 7 made from electrically conducting material. The battery which in the start procedure drives the starter motor, drives other devices when the motor of the vehicle is 5 not running, such as a clock, electrical locks, and when the vehicle is running, also fuel pump, ignition system, illumination, etc.. and electrical current then flows through the yoke 7 to another of the arms thereof, to which a cable 9 is electrically connected. To the third of the arms of the yoke the electrical generator of the vehicle is electrically connected through a connection cable 11. o The electrically conducting yoke 7 has generally the shape of a plate or low straight circular cylinder having flat surfaces on the envelope surface or edges thereof for attaching the electrical terminals. The flat surfaces that are parallel to the cylinder axis are regularly spaced or symmetrically arranged at the same distance of the axis and are located in angles of 60° to each other. From the remaining portions of the envelope s surface of the cylinder recesses 13 extend towards the axis which pass through all of the thickness or height of the cylinder, extend in a radial direction, have a uniform width and end at a small distance of the axis. Within their bottom regions at the axis a cylindrical recess 15 is provided, see also Fig. 5, that extends upwards from the underside of the yoke, so that at the region between the bottoms of the recesses the material thickness of o the yoke is significantly reduced.

In the recesses 15 claw portions of an intermediate part 17 made from electrically isolating material such as a suitable polymer material are engaged. The claw portions project upwards from an intermediate cylindrical portion of the intermediate part 17, which intermediate portion has a larger diameter and at the bottom thereof continues to a 5 cylindrical portion having a smaller diameter. The intermediate part 17 is attached to the yoke 7 by screws 19 extending through holes in the intermediate portion into threaded holes in the bottom side of the yoke. From the underside of the intermediate part 17 a through-hole extends along the axis, in which a pipe 21 is attached by threadings. The pipe 21 mainly comprises a tube having threads on its outer side and it carries at its 0 lower end a house 23 for a detonator 25, see Fig. 3. The detonator or ignition cap 25 is through lines 27 connected to an electrical collision detector, not shown.

In the pipe 21 a projectile 29 is provided. It can be designed as a somewhat elongated cylinder having flat end surfaces. It is maintained in its place inside the pipe 21 in some suitable way, for example by a thin and narrow bridge 31 made of the isolating material in the intermediate part 17. The projectile can also be designed to have a concave top surface, see the sectional view of Fig. 4, so that cutting edges 33 are formed at the end thereof at the top on its envelope surface. In the case where the projectile has a flat top surface, a separate knife part 35 having the shape of a low cylinder and having a top surface configured in the same way including a concave surface and cutting edges be arranged in the top portion of the running path of the projectile 9 that is formed by the hole in the pipe 21. the top portion of the hole in the intermediate part 17 and the cylindrical recess 15 in the bottom surface of the yoke 7. The knife part 35 can be retained in some suitable way, for example by upsetting the edge thereof or by parts, not shown, projecting from the isolating intermediate part 17.

The operation of the interruption mechanism 1 will now be described. For a heavy blow to the vehicle such as in a collision the collision detector, not shown, triggers an electrical pulse which through the cable 27 ignites the detonator 25 and makes it detonate. Then gases are evolved driving the projectile 29 upwards, thereby breaking the possible bridge 31 and then breaking through the yoke 7 at its central thinner portion and then continues to travel away from the interruption mechanism. The electrical connection between the positive terminal 3 of the battery and the connection cables 9, 11 and between these cables mutually is interrupted. None of the electrical devices of the vehicle will thus obtain any current supply thereafter, neither the battery nor the generator. For a projectile having an edge the breakthrough of the yoke can be made easier and produce smaller portions thereof which are bent upwards. For a separate knife part 35 among other things a hole having a larger diameter can be made when the projectile breaks through what can be advantageous since then the recesses 13 do not have to be so deep but can have at their bottom a somewhat larger distance of the axis resulting in a larger area of the electrical current in the central portion of the yoke and thereby smaller electrical losses.

Claims

CLAIMS 1. A device for protecting a vehicle comprising an interruption mechamsm connected to a pole of a starter battery of the vehicle and further comprising a detonator to interrupt, for a heavy blow to the vehicle such as in a collision, one of the electrical 5 connections of the battery with remaining parts of electrical system of the vehicle, so that they do not any longer obtain any current supply, characterized in that the detonator is arranged to also interrupt, when interrupting the electrical connections of the battery, the electrical connection between an electrical generator of the vehicle and devices in the vehicle that are driven by electrical current. o 2. A device according to claim 1. characterized in that the interruption mechanism comprises an electrically conducting yoke having a thin intermediate portion against which the detonator acts when triggered.

3. A device according to claim 2. characterized in that the electrical conducting yoke through an electrically conducting prolongation part is directly mounted to a pole of s the battery.

4. A device according to any of claims 2 - 3, characterized in that the yoke has at least two arms, one of which is electrically connected to a pole of the battery.

5. A device according to any of claims 1 - 4, characterized in that the interruption mechanism comprises an electrically conducting yoke having three arms, one arm of o which is electrically connected to a pole of the battery, one arm to an electrical generator of the vehicle and one arm to devices of the vehicle which are driven by electrical current.

6. A device according to any of claims 1 - 5, characterized in that the interruption mechanism comprises an electrically conducting yoke made as a plate having recesses 5 extending from the edges of the plate towards the centre thereof, so that an intermediate portion is obtained at the centre of the plate between the innermost portions of the recesses, the detonator being arranged to act against the intermediate portion when triggered.

7. A device according to claim 6, characterized in that the plate at its centre has a o reduced thickness compared to portions of the plate located at the edges thereof.

8. A device according to any of claims 2 - 7, characterized by a projectile provided at the detonator which when triggered is driven towards the yoke.

9. A device according to claim 8, characterized in that the projectile at its front end has edges extending from the end surface at this end. which are arranged at the edge 5 of the end surface to form a concave surface at this end.

10. A device according to claim 8, characterized by a knife part having edges at a front end and an external side for forming a concave surface at this end and arranged to be driven by the projectile towards the yoke when the detonator is triggered.

11. A method of protecting a vehicle, in which, for a heavy blow to vehicle such as in a collision, the electrical connections of an electrical battery or an electrical accumulator with other parts of the electrical system of the vehicle are interrupted so that they do not any longer obtain any current supply, characterized in that the interrupting is produced by detonating an explosive charge and that in the interrupting also the connection between a generator of the vehicle and electrical devices located in the vehicle and driven by electrical current is interrupted.