Apparatus and method for automatically detecting and alerting of gas-out conditions for a gas appliance during operation

An apparatus for detecting gas-out conditions of a gas-operated appliance during operation, comprising:

• (a) a piston carried within a piston cylinder and movable in response to the flow of gas through said piston cylinder between a first position where gas flow through said piston cylinder is substantially unrestricted and a second position where no sustained gas flow through said piston cylinder is present;
• (b) a first sensor operatively disposed adjacent said first position within said piston cylinder for activation upon movement of said piston to said first position and deactivation upon movement of said piston away from said first position;
• (c) a second sensor operatively disposed adjacent said second position within said piston cylinder for activation upon movement of said piston to said second position and deactivation upon movement of said piston away from said second position;
• (d) a gas flow analyzer operatively connected to said first sensor and said second sensor for detecting the difference between the gas-operated appliance running out of gas during operation and the gas to the gas-operated appliance being intentionally turned off based on the timing for said piston to move from said first position to said second position within said piston cylinder.

A method for detecting gas-out conditions of a gas-operated appliance during operation, comprising the steps of:

• (a) providing a piston carried within a piston cylinder which is movable in response to the flow of gas through said piston cylinder between a first position where the flow of gas is substantially unrestricted and a second position where no sustained gas flow through said piston cylinder is present;
• (b) determining the time it takes for said piston to travel from said first position within said piston cylinder to said second position within said piston cylinder as the rate of gas flow through said piston cylinder diminishes;
• (c) comparing the time it takes for said piston to travel from said first position within said piston cylinder to said second position with a predetermined timing threshold value;
• (d) providing an alarm that the gas-operated appliance has run out of gas as opposed to being intentionally turned off if the travel time of said piston from said first position to said second position within said piston cylinder exceeds said predetermined timing threshold.