Patent ID: 7516806

Claim:
A self-propelled vehicle comprising: wheels on which the vehicle travels, a least some of which wheels are driven to self-propel the vehicle when the vehicle is being operated; a heat removal system for removing heat from a confined space containing a device that generates heat when the vehicle is being operated; the heat removal system comprising a collection sub-system for collecting heat in the confined space, a conveyance sub-system for conveying heat from the collection sub-system to an exit sub-system, the conveyance sub-system being disposed between the collection sub-system and the exit sub-system so that heat collected at the collection sub-system is conveyed through the conveyance sub-system to the exit sub-system, and a sensor sub-system for allowing and disallowing conveyance of heat collected by the collection sub-system through the conveyance sub-system to the exit sub-system based on temperature in the confined space; wherein the exit sub-system is open to ambient atmosphere and is constructed and arranged to apply to the conveyance sub-system a partial vacuum that is created as a result of the vehicle being operated, and when the sensor sub-system allows conveyance of heat, the partial vacuum creates natural aspiration of air carrying heat from the collection sub-system through the conveyance sub-system and the exit sub-system to ambient atmosphere thereby removing heat from the confined space to ambient atmosphere; and wherein the sensor sub-system comprises a ferromagnetic part characterized by a Curie Temperature defining the lower limit of a temperature range that causes the part to lose ferromagnetism when heated to a temperature within the range, and the ferromagnetic part functions to allow the natural aspiration when the part's temperature is within the range and to disallow the natural aspiration when the part's temperature is not within the range.