Battery powered vehicle

Abstract

A vehicle is disclosed which is powered at least in part by an assembly of interconnected battery units located within one or more housings secured to or forming part of the structure of the vehicle. The, or each, housing includes a cover which overlies the sides and upper surfaces of the or each said assembly of battery units and which is coated or lined on its surface immediately above or in contact with said assembly with an intumescent-containing material which expands rapidly in the presence of excessive heat caused by a fire occurring within said assembly. Expansion of the intumescent-containing material creates a barrier which prevents transmission of the fire to other parts of said vehicle. The cover may also include a sealed thermoplastic tube which contains an extinguishing gas or fluid which is released from the tube in the event of a fire occurring within the housing.

Description

This invention relates to a vehicle powered at least in part by an assembly of interconnected battery units. BACKGROUND TO THE INVENTION Electrically powered vehicles generally require one or more banks of inter-connected individual batteries, each battery bank typically comprising between twenty and forty batteries. Conventionally, these batteries are located in one or more closable housings typically secured to the underside of the vehicle chassis, electrical cabling passing between each battery and the relevant component or components of the vehicle's engine . A significant problem with such vehicles is that, in the event that one or more batteries fail, the extra load placed on the remaining batteries is likely to cause one or more of these to overheat and, in time, ignite to set fire to the vehicle itself with potential harm or loss of life to any occupants of the vehicle . The present invention sets out to provide a solution to this problem by ensuring that any fire occasioned by such an event is automatically and rapidly extinguished to prevent it spreading to other areas of the vehicle. SUMMARY OF THE INVENTION In one aspect the invention provides a vehicle which is powered at least in part by an assembly of interconnected battery units located within one or more housings secured to or forming part of the structure of said vehicle, the or each housing including a cover which overlies the sides and upper surfaces of the or each said assembly of battery units and which is coated or lined on its surface immediately above or in contact with said assembly with an intumescent-containing material which expands rapidly in the presence of excessive heat caused by a fire occurring within said assembly to create a barrier which prevents its transmission to other parts of said vehicle. Preferably the cover comprises a cloth or fabric material. The cover may be coated on both surfaces with said intumescent-containing material. Preferably, the cover is formed with at least one ventilation opening which is rapidly closed in the event of a fire through expansion of the intumescent material. The cover of cloth or fabric material may lie in contact with individual batteries of the battery unit or may be spaced therefrom. In the latter context, the cover of cloth or fabric material may be supported by a frame. The cover may include a sealed thermoplastic tube which contains an extinguishing gas or fluid which is released from the tube in the event of a fire occurring within the housing. In a second aspect, the invention provides a vehicle which is powered at least in part by an assembly of interconnected battery units located within a housing secured to or forming part of the structure of said vehicle, wherein the housing includes a cover of a cloth or fabric material which overlies the sides and upper surfaces of said battery units, and wherein the cover is produced essentially or entirely from a material which intumesces in the event of it being exposed to excessive heat, the fire-proofed cover being formed with one or more discrete openings through which electrical cabling can pass. DETAILED DESCRIPTION OF THE INVENTION In a preferred embodiment of the invention, an assembly of interconnected battery units is located within a housing secured to the underside of a vehicle. Typically, the assembly comprises between 20 and 40 inter-connected batteries. Located within the or each housing is a cover which lies above and around the sides of the assembled battery units and is produced from a sheet or sheets of cloth or fabric material (hereinafter referred to simply as "cloth material") coated on one or each side with a solution which includes an intumescent containing material which, when exposed to high temperatures as would be experienced in the event of a fire, expands rapidly to create a char barrier which contains the fire and prevents its progression to other parts of the vehicle. A preferred cloth material comprises 400 gramme cloth impregnated with the Applicant's intumescent containing coating HW01. Other similar intumescent containing coatings may be employed. The sheet of cloth material is positioned immediately above and around the sides of a bank of interconnected batteries of the vehicle. The sheet preferably lies in contact with the upper surfaces of the batteries: alternatively, the sheet may be supported by a frame of, for example a metallic or plastics material at a position immediately above and in close proximity to the upper surfaces and sides of the bank of batteries. A vehicle may include one or a plurality of such banks of batteries each located and covered as described above. In use, in the event of a fire occurring within one or more of the batteries, the intumescent coating of the cloth material immediately and rapidly expands to cover completely the batteries and extinguish the fire before it causes further damage to the vehicle or harm to its occupants. Tests have demonstrated that in a conventional battery powered vehicle, should one battery become faulty and ignite when charging or in use, the resulting fire will cause all batteries of the bank to ignite causing damage and harm not only to the vehicle but also to the occupants and environs of the vehicle. In a preferred embodiment, the fire-proofed cover is produced by simply stitching suitably dimensioned coated cloth pieces together to form a suitably shaped and dimensioned housing. The housing may include one or more ventilation openings to assist cooling of the housing interior. In an alternative embodiment, the sheet of cloth material coated with an intumescent containing material is adhered to the underside of an aluminium closure panel of an enclosure in which the battery units are located. A suitable adhesive is the Applicant's 1A adhesive which expands significantly in the presence of excessive heat. In use, in the event of a fire, the cloth will drop onto the batteries to provide a complete seal and extinguish said fire. A fire / smoke alarm system may be incorporated within the or each housing to alert the user to a potential hazard of a fire or an impending fire. 5 It will be appreciated that the foregoing is merely exemplary of fire-proofed enclosures in accordance with the invention and that modifications can readily be made thereto without departing from the true scope of the invention as set out in the appended claims . 10

Claims

1. A vehicle which is powered at least in part by an assembly of interconnected battery units located within one or more 5 housings secured to or forming part of the structure ofsaid vehicle, the or each housing including a cover which overlies the sides and upper surfaces of the or each said assembly of battery units and which is coated or lined on its surface immediately above or in contact with said 10 assembly with an intumescent-containing material whichexpands rapidly in the presence of excessive heat caused by a fire occurring within said assembly to create a barrier which prevents its transmission to other parts of said vehicle, and wherein the cover is formed with at least one 15 ventilation opening which is closed in the event of a firethrough expansion of the intumescent-containing material.2 . A vehicle as claimed in claim 1 wherein the cover comprises a cloth or fabric material.

203. A vehicle as claimed in claim 1 or claim 2 wherein the cover is coated on both surfaces with said intumescent-containing material.25 4. A vehicle as claimed in any one of the preceding claimswherein the cover lies in contact with the battery units.

5. A vehicle as claimed in any one of claims 1 to 3 wherein the cover is spaced from the batteries.

306. A vehicle as claimed in claim 5 wherein the cover is supported by a frame.

7. A vehicle as claimed in any one of the preceding claims wherein the cover is formed with one or more discrete openings through which electrical cabling can pass.