Compressed Natural Gas Vehicle Safety System and Method

摘要

A multiply-redundant system that prevents a driver from starting and/or moving a vehicle if a compressed natural gas fill system is not correctly and completely disconnected from the vehicle. One or more sensors in combination with one or more optional microswitches combine to lock-out the vehicle's ignition or otherwise prevent it from starting and/or moving. For different levels of safety, different combinations of sensors can be used with the lowest level having a single proximity sensor sensing the presence or absence of a high-pressure fill hose. The highest level of safety being achieved by having separate proximity sensors on the fuel fill hose fitting, the gas cap cover and a manual safety valve along with a redundant microswitch. An optional override that may be restricted as to the number of times it can be used can allow starting with a faulty sensor in order to allow maintenance.

主权项

1. A vehicle safety system for disabling a natural gas-fueled vehicle while fueling, comprising:
a first sensor adapted to sense presence of a gas fill hose in proximity to a tank fill adapter coupled to a pressurized gas source; a second sensor adapted to sense an open/closed position of an isolation valve, said isolation valve isolating said tank fill adapter from said gas source when closed; a logic circuit adapted to combine inputs from said first and second sensors to produce a safe electrical signal indicating a safe condition when said fill hose is not in proximity to said tank fill adapter, and said isolation valve is closed; a lockout circuit adapted to disable said vehicle when said safe electrical signal is absent.