Claims
- 1. A fuel dispenser comprising:
- a gas detector for producing an electrical signal in dependence upon the presence of gas in fuel flowing through the chambers separated by a movable member, said first closed chamber having an inlet and an outlet, said second chamber being connected to said outlet by a passage, whereby fuel passing through said inlet and said outlet produces a reduction in pressure in said first chamber by the Venturi effect; and
- processing means for receiving the electrical signal and controlling the dispensing of fuel at least in part in dependence upon the electrical signal received.
- 2. A fuel dispenser as claimed in claim 1 further comprising a fuel separator including an inlet for receiving fuel and first and second outlets, wherein the first outlet is positioned such as to receive a greater proportion of gas than the second outlet, and wherein the gas detector receives fuel from the first outlet, and fuel for dispensing is received from the second outlet.
- 3. A fuel dispenser as claimed in claim 2 wherein fuel passing through the gas detector is recycled through the separator.
- 4. A fuel dispenser as claimed in claim 2 wherein fuel from the second outlet of the separator passes through a meter before being dispensed.
- 5. A fuel dispenser as claimed in claim 1, further comprising a vented reservoir, wherein fuel after passing through the gas detector, flow into said vented reservoir.
- 6. A fuel dispenser as claimed in claim 1 including a restriction in the outlet downstream from the connection to the passage.
- 7. A fuel dispenser as claimed in claim 1 wherein the gas detector comprises a metallic member attached to a movable member such that the metallic member moves into and out of a magnetic field between a magnetic source of the detector and a magnetically sensitive switching element in the casing of the detector for producing said electrical signal.
- 8. A fuel dispenser as claimed in claim 1 further comprising a nozzle through which fuel is dispensed, the nozzle being attached to a main body of the dispenser by a flexible hose, wherein the dispenser includes a cradle for the nozzle to be returned to when not in use, and a hose cock switch for transmitting a signal to the processing means indicative of the presence or absence of the nozzle in the cradle.
- 9. A fuel dispenser as claimed in claim 8 wherein once gas free fuel has been detected after the nozzle has been removed from the cradle the processing means causes a valve to open allowing fuel to be dispensed, and to cause the valve to close if gas is then detected.
- 10. A fuel dispenser as claimed in claim 9 wherein the processing means causes the valve to open again if gas-free fuel is again detected in a predetermined period after the initial closing of the valve and causes the valve to remain closed until the nozzle has been returned to its cradle if gas-free fuel is not detected in said period.
- 11. A fuel dispenser as claimed in claim 9, wherein the processing means records the duration for which gas is detected and uses this information to determine whether the fuel so far dispensed is within predetermined metrological limits for the amount of fuel so far dispensed in the transaction, and controls the valve accordingly.
- 12. A fuel dispenser as claimed in claim 9 wherein the valve has more than one setting permitting flow rate to be modified.
- 13. A fuel dispenser as claimed in claim 8 wherein the valve remains closed until the nozzle has been returned to the cradle.
- 14. A fuel dispenser as claimed in claim 1 wherein the processing means records the duration for which gas is detected and provides a warning if this exceeds a predetermined limit.
- 15. A gas detector for detecting the presence of gas in a fuel and providing an electrical signal output in dependence thereon, the detector comprising a first and a second closed chamber separated by a movable member, and an inlet and outlet in the first chamber of such dimensions and relative displacement that fuel passing through them produces a reduction in pressure in the first chamber by the Venturi effect, the second chamber being connected by a passage to the outlet.
- 16. A gas detector as claimed in claim 15 including a restriction in the outlet downstream from the connection to the passage.
- 17. A gas detector as claimed in claim 15 comprising a metallic member attached to a movable member which is adapted to be moved by the moveable member into and out of a magnetic field between a magnetic source of the detector and a magnetically sensitive switching element in the casing of the detector for producing said electrical signal.
- 18. A method of dispensing fuel comprising producing an electrical signal in dependence upon the presence of gas in fuel flowing through a gas detector, processing the electrical signal and controlling dispensing of fuel at least in part in dependence upon the electrical signal received.
- 19. A method as claimed in claim 18 including passing fuel into a fuel separator through an inlet, said fuel separator having first and second outlets wherein the first outlet is positioned such as to receive a greater proportion of gas than the second outlet, and passing fuel from the first outlet to the gas detector and receiving fuel for dispensing from the second outlet.
- 20. A method as claimed in claim 19 including recycling through the fuel separator the fuel passing through the gas detector.
- 21. A method as claimed in claim 19 including passing fuel from the second outlet of the separator through a meter prior to the fuel being dispensed.
- 22. A method as claimed in claim 21 including passing fuel from the gas detector into a vented reservoir.
- 23. A method as claimed in claim 18 including detecting the presence of gas by means of a venturi device.
- 24. A method as claimed in claim 18 wherein the gas detector comprises a first and a second closed chamber separated by a movable member, and an inlet and outlet in the first chamber of such dimensions and relative displacement that fuel passing through them produces a reduction in pressure in the first chamber by the Venturi effect, the second chamber being connected by a passage to the outlet.
- 25. A method as claimed in claim 24 including passing fuel through a restriction in the outlet downstream from the connection to the passage.
- 26. A method as claimed in claim 18 wherein the gas detector comprises a metallic member attached to a movable member such that the metallic member moves into and out of a magnetic field between a magnetic source of the detector and a magnetically sensitive switching element in the casing of the detector for producing said electrical signal.
- 27. A method as claimed in claim 18 further comprising dispensing fuel through a nozzle, the nozzle being attached to a main body of the dispenser by a flexible hose, wherein the dispenser includes a cradle for the nozzle to be returned to when not in use, and a hose cock switch for transmitting a signal to the processing means indicative of the presence or absence of the nozzle in the cradle.
- 28. A method as claimed in claim 27 wherein once gas free fuel has been detected after the nozzle has been removed from the cradle the processing means opens a valve allowing fuel to be dispensed, and closes the valve if gas is then detected.
- 29. A method as claimed in claim 28 wherein the processing means opens the valve again if gas-free fuel is again detected in a predetermined period after the initial closing of the valve and causes the valve to remain closed until the nozzle has been returned to its cradle if gas-free fuel is not detected in said period.
- 30. A method as claimed in claim 28, including recording the duration for which gas is detected and using this information to determine whether the fuel so far dispensed is within predetermined metrological limits for the amount of fuel so far dispensed in the transaction, and controlling the valve accordingly.
- 31. A method as claimed in claim 28 wherein the valve has more than one setting permitting flow rate to be modified.
- 32. A method as claimed in claim 27 wherein the valve remains closed until the nozzle has been returned to the cradle.
- 33. A method as claimed in claim 18 including recording the duration for which gas is detected and providing a warning if this exceeds a predetermined limit.
Priority Claims (1)
Number |
Date |
Country |
Kind |
9119605 |
Sep 1991 |
GBX |
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CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of application Ser. No. 07/940,243, filed Sept. 8th, 1992, now abandoned.
US Referenced Citations (10)
Foreign Referenced Citations (7)
Number |
Date |
Country |
4852272 |
May 1974 |
AUX |
313095 |
Jan 1974 |
ATX |
522869 |
Mar 1956 |
CAX |
0357513 |
Mar 1990 |
EPX |
0473818 |
Mar 1992 |
EPX |
2530168 |
Jan 1977 |
DEX |
200159 |
Feb 1939 |
CHX |
Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
940243 |
Sep 1992 |
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