초록 ▼

A flow switch used in conjunction with a fuel meter in a fuel dispenser to determine when fuel is flowing. A flow switch can only be activated if fuel is flowing through the flow path of the flow switch. If fuel is flowing as indicated by the fuel flow switch, but the meter is not registering fuel

A flow switch used in conjunction with a fuel meter in a fuel dispenser to determine when fuel is flowing. A flow switch can only be activated if fuel is flowing through the flow path of the flow switch. If fuel is flowing as indicated by the fuel flow switch, but the meter is not registering fuel flow, there is a meter error, which may be an error internally with components of the meter and/or a pulser that generates pulse signals indicative of fuel flow. If the meter pulser is registering fuel flow, but the flow switch is not registering fuel flow, then an error exists with the flow switch. If fuel is flowing and there are no errors, both the meter and the flow switch should indicate fuel flow.

대표청구항 ▼

What is claimed is: 1. A fuel dispenser that measures the flow rate or volume of fuel dispensed into a vehicle, comprising: a control system; a fuel conduit that is fluidly coupled to fuel; a meter coupled to the fuel conduit, comprising: a meter flow path coupled to a hose that dispenses the fuel

What is claimed is: 1. A fuel dispenser that measures the flow rate or volume of fuel dispensed into a vehicle, comprising: a control system; a fuel conduit that is fluidly coupled to fuel; a meter coupled to the fuel conduit, comprising: a meter flow path coupled to a hose that dispenses the fuel to the vehicle; and a pulser that sends a pulser signal in relation to the flow of fuel through the meter flow path to the control system; and a flow switch coupled to the fuel conduit, comprising: a flow switch flow path; and a sensor that communicates a flow switch signal to the control system when the fuel is passing through the flow switch flow path; the flow switch flow path fluidly coupled to the meter flow path such that fuel that passes through the meter flow path also passes through the flow switch flow path; the control system receives the pulser signal and calculates a flow rate or volume of the fuel passing through the meter flow path based on the pulser signal; and the control system detects a flow switch error when the pulser signal is being received and the flow switch signal is not received, or a meter error when the flow switch signal is being received and the pulser signal is not being received. 2. The fuel dispenser of claim 1, wherein the control system detects the flow switch error when the pulser signal is being received and the flow switch signal is not received within a predetermined amount of time. 3. The fuel dispenser of claim 1, wherein the control system detects the meter error when the flow switch signal is being received and the pulser signal is not received within a predetermined amount of time. 4. The fuel dispenser of claim 1, further comprising a pulser timer coupled to the control system wherein the control system starts the pulser timer when the pulser signal is received and generates the meter error if the pulser timer times out while the flow switch signal is being received. 5. The fuel dispenser of claim 1, further comprising a flow switch timer coupled to the control system wherein the control system starts the flow switch timer when the flow switch signal is received and generates the flow switch error if the flow switch timer times out while the pulser signal is being received. 6. The fuel dispenser of claim 1, further comprising a pulser timer coupled to the control system wherein the control system starts the pulser timer when the pulser signal is received. 7. The fuel dispenser of claim 6, further comprising a flow switch timer coupled to the control system wherein the control system starts the flow switch timer when the pulser signal is received. 8. The fuel dispenser of claim 7, wherein the control system restarts the pulser timer and stops the flow switch timer when the flow switch signal is received. 9. The fuel dispenser of claim 8, wherein the control system restarts the pulser timer as long as the pulser signal is continued to be received before the pulser timer times out. 10. The fuel dispenser of claim 8, wherein the control system generates the meter error if the pulser signal is not received before the pulser timer times out. 11. The fuel dispenser of claim 8, wherein the control system stops the pulser timer if the flow switch signal is not further received. 12. The fuel dispenser of claim 7, wherein the control system stops the flow switch timer if the pulser signal is not further received before the pulser timer times out. 13. The fuel dispenser of claim 7, wherein the control system generates a flow switch error if the flow switch timer times out before the flow switch signal is received. 14. The fuel dispenser of claim 1, further comprising a pulser timer coupled to the control system wherein the control system starts the pulser timer when the flow switch signal is received. 15. The fuel dispenser of claim 1, wherein the flow switch is located in a position comprised from the group consisting of upstream of the meter and downstream of the meter. 16. The fuel dispenser of claim 1, wherein the flow switch further comprises: a housing; and a primary fuel flow path positioned within the housing comprising: a piston; and a spring holding the piston in a normally closed position. 17. The fuel dispenser of claim 16, wherein the sensor is adapted to sense movement of the piston and report movement of the piston to the control system by communicating the flow switch signal to the control system. 18. The fuel dispenser of claim 17, wherein the piston further comprises a position sensible element. 19. The fuel dispenser of claim 18, wherein the position sensible element comprises a magnet and the sensor comprises a Hall-effect sensor. 20. The fuel dispenser of claim 17, wherein the sensor comprises an element selected from the group consisting of: a magnetic reed switch arrangement, a capacitive sensor, an ultrasonic sensor, and a Hall-effect sensor. 21. The fuel dispenser of claim 1, wherein the flow switch is comprised of: a valve body; a poppet head; an o-ring; a relief valve wherein the relief valve is coupled between the valve body and the o-ring and wherein the o-ring is coupled between the relief valve and the poppet head; a washer; and a spring coupled between the poppet head and the washer; the poppet head adapted to compress the spring towards the washer when a force is applied to the side of the poppet head coupled to the o-ring. 22. The fuel dispenser of claim 1, wherein the flow switch further comprises: a housing; a primary fuel flow path positioned within the housing comprising: a primary piston; and a primary spring holding the primary piston in a normally closed position; a secondary fuel flow path positioned within the housing, fluidly connected to the primary fuel flow path and passing around the primary piston, the secondary fuel flow path comprising: a secondary piston; and a secondary spring holding the secondary piston in a normally closed position, the secondary spring requiring less force to compress than the primary spring. 23. The fuel dispenser of claim 22, wherein the sensor is adapted to sense movement of the secondary piston and report movement of the secondary piston to the control system. 24. The fuel dispenser of claim 23, wherein the secondary piston further comprises a position sensible element. 25. The fuel dispenser of claim 24, wherein the position sensible element comprises a magnet and the sensor comprises a Hall-effect sensor. 26. The fuel dispenser of claim 25, wherein the sensor comprises an element selected from the group consisting of: a magnetic reed switch arrangement, a capacitive sensor, an ultrasonic sensor, and a Hall-Effect sensor. 27. The fuel dispenser of claim 1, wherein the flow switch error or meter error is communicated by the control system to a system comprised from the group consisting of a site controller, a tank monitor, and a remote system. 28. The fuel dispenser of claim 27, wherein the flow switch error or meter error is communicated by the site controller or the tank monitor to the remote system. 29. A system that measures the flow rate or volume of a fluid, comprising: a control system; a meter, comprising: a meter flow path coupled to the fluid conduit; and a pulser that sends a pulser signal in relation to the flow of fluid through the meter flow path to the control system; and a flow switch coupled to the fluid conduit, comprising: a flow switch flow path; and a sensor that communicates a flow switch signal to the control system when the fluid is passing through the flow switch flow path; the flow switch flow path fluidly coupled to the meter flow path such that fluid that passes through the meter flow path also passes through the flow switch flow path; the control system receives the pulser signal and calculates a flow rate or volume of the fluid passing through the meter flow path based on the pulser signal; and the control system detects a flow switch error when the pulser signal is being received and the flow switch signal is not received, or a meter error when the flow switch signal is being received and the pulser signal is not being received. 30. The system of claim 29, wherein the control system detects the flow switch error when the pulser signal is being received and the flow switch signal is not received within a predetermined amount of time. 31. The system of claim 29, wherein the control system detects the meter error when the flow switch signal is being received and the pulser signal is not received within a predetermined amount of time. 32. The system of claim 29, further comprising a pulser timer coupled to the control system wherein the control system starts the pulser timer when the pulser signal is received and generates the meter error if the pulser timer times out while the flow switch signal is being received. 33. The system of claim 29, further comprising a flow switch timer coupled to the control system wherein the control system starts the flow switch timer when the flow switch signal is received and generates the flow switch error if the flow switch timer times out while the pulser signal is being received. 34. The system of claim 29, wherein the flow switch error or meter error is communicated by the control system to another system. 35. A method of determining an error in a fuel dispenser that dispensed fuel to a vehicle, comprising the steps of: passing the fuel through the flow path of a meter; the meter generating a pulser signal in response to the fuel passing through the flow path of the meter when the meter is operating properly; passing the fuel through a flow switch fluidly coupled to the flow path; the flow switch generating a flow switch signal in response to fuel passing through the flow switch when the flow switch is operating properly; determining the flow rate or volume of fuel passing through the flow path of the meter based on the pulser signal; generating a flow switch error if the pulser signal is being received by a control system and the flow switch signal is not being received by the control system; and generating a meter error when the flow switch signal is being received by the control system and the pulser signal is not being received by the control system. 36. The method of claim 35, further comprising detecting the flow switch error when the pulser signal is being received by the control system and the flow switch signal is not received by the control system within a predetermined amount of time. 37. The method of claim 35, further comprising detecting the meter error when the flow switch signal is being received by the control system and the pulser signal is not received by the control system within a predetermined amount of time. 38. The method of claim 35, further comprising: starting a pulser timer coupled to the control system when the pulser signal is received by the control system; and generating the meter error if the pulser timer times out while the flow switch signal is being received by the control system. 39. The method of claim 35, further comprising: starting the flow switch timer coupled to the control system when the flow switch signal is received by the control system; and generating the flow switch error if the flow switch timer times out while the pulser signal is being received by the control system. 40. The method of claim 39, further comprising the step of the control system communicating the flow switch error or meter error to a system comprised from the group consisting of a site controller, a tank monitor, and a remote system. 41. The method of claim 40, further comprising the site controller or the tank monitor communicating the flow switch error or meter error to the remote system. 42. The method of claim 39, further comprising the step of the control system communicating the flow switch error or meter error to another system. 43. The method of claim 35, further comprising starting a pulser timer coupled to the control system when the pulser signal is received by the control system. 44. The method of claim 43, further comprising starting a flow switch timer coupled to the control system when the pulser signal is received by the control system. 45. The method of claim 44, further comprising restarting the pulser timer and stopping the flow switch timer when the flow switch signal is received by the control system. 46. The method of claim 45, further comprising restarting the pulser timer as long as the pulser signal is continued by the control system to be received before the pulser timer times out. 47. The method of claim 45, further comprising generating the meter error if the pulser signal is not received by the control system before the pulser timer times out. 48. The method of claim 45, further comprising stopping the pulser timer if the flow switch signal is not further received by the control system. 49. The method of claim 44, further comprising stopping the flow switch timer if the pulser signal is not further received by the control system before the pulser timer times out. 50. The method of claim 44, further comprising generating a flow switch error if the flow switch timer times out before the flow switch signal is received by the control system. 51. The fuel dispenser of claim 35, further comprising starting a pulser timer coupled to the control system when the flow switch signal is received by the control system. 52. The method of claim 35, wherein the step of generating a flow switch signal comprises sensing the movement of a piston in a flow switch housing that moves in response to fluid passing through the flow switch housing. 53. The method of claim 52, further comprising: sensing movement of the piston; and reporting movement of the piston to a control system by communicating the flow switch signal to the control system. 54. The method of claim 53, wherein the step of sensing the movement of the piston comprises sensing a position sensible element on the piston. 55. The method of claim 52, further comprising releasing a relief valve in the flow switch housing if the flow switch becomes over-pressurized. 56. The method of claim 35, wherein the step of generating a flow switch signal comprises: initiating the dispensing of fuel; opening partially a two-stage valve adapted to regulate fuel flow into a flow rate selected from the group consisting of: no flow, slow flow and high flow; measuring the flow rate of the fuel; compressing a secondary spring in a secondary piston in a dual piston valve to open a secondary fuel path; detecting movement of a sensible element in the dual piston valve when the secondary piston moves; and communicating the movement of the secondary piston to the control system; dispensing the fuel in a slow flow state; opening fully the two-stage valve; compressing a primary spring in a primary piston in the dual piston valve to open a primary fuel path; and dispensing the fuel in a high flow state. 57. A method of determining an error in a system that measures the flow rate or volume of a fluid, comprising the steps of: passing the fluid through the flow path of a meter; the meter generating a pulser signal in response to the fluid passing through the flow path of the meter when the meter is operating properly; passing the fluid through a flow switch fluidly coupled to the flow path; the flow switch generating a flow switch signal in response to fluid passing through the flow switch when the flow switch is operating properly; determining the flow rate or volume of the fluid passing through the flow path of the meter based on the pulser signal; generating a flow switch error if the pulser signal is being received by a control system and the flow switch signal is not being received by the control system; and generating a meter error when the flow switch signal is being received by the control system and the pulser signal is not being received by the control system. 58. The method of claim 57, further comprising detecting the flow switch error when the pulser signal is being received by the control system and the flow switch signal is not received by the control system within a predetermined amount of time. 59. The method of claim 57, further comprising detecting the meter error when the flow switch signal is being received by the control system and the pulser signal is not received by the control system within a predetermined amount of time. 60. The method of claim 57, further comprising: starting a pulser timer coupled to the control system when the pulser signal is received by the control system; and generating the meter error if the pulser timer times out while the flow switch signal is being received by the control system. 61. The method of claim 57, further comprising: starting the flow switch timer coupled to the control system when the flow switch signal is received by the control system; and generating the flow switch error if the flow switch timer times out while the pulser signal is being received by the control system.