×

Onboard vapor recovery system with two-stage shutoff valve

  • US 5,797,434 A
  • Filed: 09/13/1996
  • Issued: 08/25/1998
  • Est. Priority Date: 08/24/1994
  • Status: Expired due to Fees
First Claim
Patent Images

1. In a vehicle fuel system having a fuel tank, a dynamically-sealed filler pipe, and onboard vapor recovery apparatus, a fuel vapor venting control system comprising:

  • control valve means in the fuel tank for venting fuel vapor from the tank to the vapor recovery apparatus at a first higher rate when the fulel level in the tank is below a first level, at a second lower rate when the fulel level in the tank reaches the first level, and for closing when a second higher fuel level in the tank is reached, the control valve means comprising two stage offset valve means responsive to the level of liquid fuel in the tank, the offset valve means further comprising liquid level responsive float means, first and second valve means associated with the float means, and first and second vent outlet means, the float means being responsive to liquid fuel reaching the first level to force the first valve means to a position closing the first vent outlet means, the first valve means further including means for biasing the first valve means from the second valve means, the float means being responsive to liquid fuel level above the first level to force the second valve means against the bias of the first valve means into sealing engagement with the second vent outlet means to close the control valve means;

    valve means in the fuel tank for maintaining a pressure head in the tank sufficient to induce filler nozzle shutoff when the control valve means is closed and for selectively venting fuel vapor to the vapor recovery apparatus independently of the control valve means; and

    check valve means in a lower end of the filler pipe to close the filler pipe with respect to the fuel tank between refueling activity.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×