Claims
- 1. A safety system for grounding an operator at a fueling station prior to removing a fuel fill nozzle from a fuel tank upon completion of a fuel filling operation, said fuel fill nozzle connected to a fuel source by a fuel conduit, said safety system comprising:a) a fuel tank port in communication with said fuel tank for receiving and retaining said fuel fill nozzle during the fuel filling operation; b) a grounding device adjacent said fuel tank port, said grounding device including a grounding switch having a contact member adapted to receive physical contact by the operator, wherein physical contact of said contact member activates said grounding switch; and c) a releasable interlock providing a lock position wherein said nozzle is locked into said port upon insertion of said nozzle into said port and a release position wherein said nozzle is releasable from said fuel tank port upon completion of the fuel filling operation and after physical contact of said contact member is accomplished; whereby accidental ignition of fuel due to static discharge is prevented.
- 2. The safety system of claim 1, wherein said grounding device is located at least 2 centimeters from said nozzle.
- 3. The safety system of claim 1, wherein the fuel source contains a compressed fuel.
- 4. The safety system of claim 1, wherein said fuel tank is a fuel cell fuel tank.
- 5. The safety system of claim 1, wherein said releasable interlock is a manually activated nozzle lever, wherein movement of said nozzle lever in a first direction locks said nozzle to said fuel tank port and wherein movement of said nozzle lever in a second direction unlocks said nozzle from said fuel tank port only upon activation of said rounding switch.
- 6. The safety system of claim 1, including a timer connected to said releasable interlock, said timer providing for said releasable interlock to remain in said release position for a limited time period subsequent to activation of said grounding switch, said timer providing for said releasable interlock to remain in said locked position at all other times when said nozzle is received in said port.
- 7. The safety system of claim 6, wherein said limited time period is about one to three hundred seconds and preferably about five seconds.
- 8. The safety system of claim 6, including an indicator to provide indication that said nozzle may safely be removed from said receptacle, said indicator providing indication during said limited time period.
- 9. The safety system of claim 1, wherein the grounding switch is integral to the releasable interlock.
- 10. The safety system of claim 9, wherein said releasable interlock is a lever adapted to move from said lock position to said release position, whereby said lever blocks said nozzle from removal from said fuel tank port until moved from said lock position to said release position.
- 11. The safety system of claim 1, including a grounding verification switch adjacent to said nozzle and a timer connected to said releasable interlock, said grounding verification switch connected to a fuel controller, said fuel controller enabling flow of said fuel from said nozzle only during activation of said grounding verification switch, said timer providing for said releasable interlock to remain in said release position for a limited time period subsequent to release of said grounding verification switch.
- 12. The safety system of claim 11, wherein said grounding verification switch includes an activation handle on said nozzle that additionally controls flow of fuel.
- 13. The safety system of claim 1, including a grounding verification switch and a timer, said grounding verification switch connected to a fuel controller, said fuel controller enabling flow of said fuel from said nozzle only during activation of said grounding verification switch, said timer connected to said fuel controller and providing for flow of fuel to resume once halted by release of said grounding verification switch for a limited time period subsequent to release of said grounding verification switch, and wherein said fuel controller provides for no fuel to flow after said limited time period has been reached until said grounding switch is re-activated.
- 14. A safety system for grounding an operator at a fueling station during a fuel filling operation, comprising:a) a fuel tank port in communication with a fuel tank for receiving a fuel fill nozzle; b) a grounding device adjacent said fuel tank port, said grounding device including a grounding switch having a contact member adapted to receive physical contact by the operator; wherein physical contact of said contact member activates said grounding switch; and c) a fuel controller for providing fuel flow through said nozzle only when said grounding switch is continuously activated; whereby accidental ignition of fuel due to static discharge is prevented.
- 15. A safety system for grounding an operator at a fueling station during a fuel filling operation, comprising:a) a fuel tank port in communication with a fuel tank for receiving a fuel fill nozzle; b) a grounding device adjacent said fuel tank port, said grounding device including a contact member connected to ground adapted to receive physical contact by the operator; c) a fuel controller for controlling fuel flow through said nozzle, said fuel controller providing for a flow of fuel and providing a signal when said controller provides fuel to stop flowing; and d) an indicator that indicates to the operator, immediately upon receiving said signal, that grounding must take place prior to removal of said nozzle; whereby accidental ignition of fuel due to static discharge is prevented.
- 16. A method for grounding an operator at a fueling station comprising the steps of:a) providing a fuel tank port in communication with a fuel tank for receiving and retaining a fuel fill nozzle during a fuel filling operation; b) providing a grounding device adjacent to the fuel tank port, the grounding device including a grounding switch having a contact member to receive physical contact by the operator, wherein physical contact of the contact member activates the grounding switch; c) providing a releasable interlock having a lock position wherein the nozzle is locked into the port upon insertion of the nozzle into the port and a release position wherein the nozzle is releasable from the fuel tank port upon completion of the fuel filling operation and after physical contact of the contact member is accomplished; d) withdrawing the fuel fill nozzle from a fuel source boot; e) inserting the fuel fill nozzle into the fuel tank port wherein the nozzle is locked into the fuel tank port; f) filling the fuel tank with fuel from a fuel source; g) contacting the contact member to activate the grounding switch of the grounding member to release the releasable interlock; and h) withdrawing the nozzle from the port; whereby accidental ignition of fuel due to static discharge is prevented.
- 17. The method of claim 16, wherein the step of providing the releasable interlock includes providing a manually activated nozzle lever, wherein movement of the nozzle lever in a first direction locks the nozzle to the fuel tank port to allow flow of fuel and wherein movement of the nozzle lever in a second direction unlocks the nozzle from the fuel tank port and is enabled only upon activation of the grounding switch, and wherein the step of contacting the contact member enables movement of the nozzle lever in the second direction.
- 18. The method of claim 16, including a step of providing a timer connected to the releasable interlock, the timer providing for the releasable interlock to remain in the release position for a limited time period subsequent to activation of the grounding switch, the timer providing for the releasable interlock to remain in the locked position at all other times when the nozzle is received in the port.
- 19. The method of claim 16, including steps of providing a fuel controller, providing a grounding verification switch and connected to the fuel controller, and providing a timer connected to the releasable interlock, the fuel controller enabling flow of the fuel from the nozzle only during activation of the grounding verification switch, the timer providing for the releasable interlock to remain in the release position for a limited time period subsequent to release of the grounding verification switch, wherein the step of contacting the contact member enables movement of the nozzle lever in the second direction for the limited time period.
- 20. The method of claim 16, including steps of providing a fuel controller, providing a grounding verification switch and connected to the fuel controller, and providing a timer, the fuel controller enabling flow of the fuel from the nozzle only during activation of the grounding verification switch, the timer connected to the fuel controller and providing for flow of fuel to resume once halted by release of the grounding verification switch for a limited time period subsequent to release of the grounding verification switch, and wherein the fuel controller provides for no fuel to flow after the limited time period has been reached until the grounding switch is re-activated , wherein the step of filling the fuel tank includes releasing the grounding verification switch during fueling thereby stopping flow of fuel and contacting the contact member to reactivate the grounding switch to restart the flow of fuel.
- 21. A method for grounding an operator at a fueling station during a fuel filling operation, comprising:a) providing a fuel tank port in communication with a fuel tank for receiving a fuel fill nozzle during the fuel filling operation; b) providing a grounding device adjacent to the fuel tank port, the grounding device including a grounding switch having a contact member to receive physical contact by the operator, wherein physical contact of the contact member activates the grounding switch; c) providing a fuel controller that is activatable by the grounding switch to provide fuel flow through the nozzle only when the grounding switch is continuously activated; and d) physically contacting the contact member to activate the grounding switch to activate the fuel controller to provide fuel flow; whereby accidental ignition of fuel due to static discharge is prevented.
- 22. A safety system for grounding an operator at a fueling station during a fuel filling operation, comprising:a) providing a fuel fill nozzle connected to a fuel source; b) providing a fuel tank port in communication with a fuel tank for receiving the fuel fill nozzle; c) providing a grounding device adjacent to the fuel tank port, the grounding device including a contact member connected to ground adapted to receive physical contact by the operator; d) providing a fuel controller for controlling fuel flow through the nozzle, the fuel controller providing a signal when the controller provides fuel to stop flowing; e) providing an indicator that indicates to the operator, immediately upon receiving the signal, that grounding must take place prior to removal of the nozzle; f) inserting the nozzle into the fuel tank port; g) inputting a desired quantity of fuel into the fuel tank via the fuel controller until the desired quantity of fuel has been transferred into the fuel tank or the fuel tank has reached capacity; h) providing the signal from the controller to the indicator to indicate to the operator that the operator must contact the contact member; i) contacting the contact member; and j) removing the nozzle from the fuel tank port; whereby accidental ignition of fuel due to static discharge is prevented.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
This invention was made with Government Support under Contract No. DE-FC08-99NV13578 between Air Products and Chemicals, Inc., and the United States Department of Energy. The Government has certain rights to this invention.
US Referenced Citations (5)
Non-Patent Literature Citations (3)
Entry |
National Fire Protection Association Code NFPA 77 “Recommended Practice on Static Electricity”, Section 4-5.3.6. |
Von Pidoll et al., “Avoidance of Electrostatic Hazards During Refueling of Motorcars,” Journal of Electrostatics, 40 & 41, 1997, pp. 523-528. |
Kassebaum & Kocken, “Controlling Static Electricity in Hazardous (Classified) Locations,” IEEE Trans. On Indus. Applics., vol. 33, No. 1, Jan./Feb. 1997. |