# US 5,345,979 A · High efficiency vapor recovery fuel dispensing > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,345,979 A - Document ID: US5345979A - Status: Granted - Kind: A - Application number: 07/968,595 - Filed: 1992-10-29 - Granted: 1994-09-13 - Earliest claimed: 1992-10-29 - Assignees: Gilbacro, Inc. - Inventors: Mark B. Tucker; Edward A. Payne; Paul D. Miller - Web page: https://patentgrep.com/patent/US5345979A ## CPC - B67D 7/0486: {Pumps driven in response to electric signals indicative of pressure, temperature or liquid flow} - B67D: DISPENSING, DELIVERING OR TRANSFERRING LIQUIDS, NOT OTHERWISE PROVIDED FOR (cleaning pipes or tubes or systems of pipes or tubes B08B9/02; emptying or filling of bottles, jars, cans, casks, barrels, or similar containers, not otherwise provided for B67C; water supply E03; pipe systems F17D; domestic hot-water supply systems F24D; measuring volume, volume flow, mass flow or liquid level, metering by volume G01F; coin-freed or like apparatus G07F) ## Abstract An apparatus for dispensing volatile liquid fuel with recovery of fuel vapors includes a fuel delivery system having a fuel delivery line and a pump in the line to pump fuel there-along to a nozzle. A vapor recovery subsystem includes a vapor return line from the nozzle and a vapor impulsion means to induce vapor to flow through the vapor return line at a vapor flow rate comparable to the liquid flow rate through the fuel delivery line during most of a fueling operation. A vapor impulsion booster boosts the vapor flow rate above the liquid flow rate early in a fueling operation. ## Claims ### Claim 1 An apparatus for dispensing volatile liquid fuel with recovery of fuel vapors comprising a fuel delivery system including a fuel delivery line and a pump in said line to pump fuel there-along to a nozzle, a vapor recovery subsystem including a vapor return line from said nozzle and a vapor impulsion means to induce vapor to flow through said vapor return line at an ordinary vapor flow rate through said fuel delivery line during most of a fueling operation, a vapor impulsion booster to boost the vapor flow rate above the ordinary vapor flow rage early in a fueling operation and subsequently permitting said vapor to flow at the ordinary vapor flow rate. ### Claim 2 (depends on 1) An apparatus as claimed in claim 1 wherein said vapor impulsion means is a vapor pump and said vapor impulsion booster comprises a valve in said vapor return line upstream of said vapor pump and a timer circuit operable to start said vapor pump before opening said valve and pumping with said liquid pump, whereby a reduced pressure may be drawn in said vapor return line before liquid is pumped, so that upon opening said valve, vapor flows rapidly into said vapor return line. ### Claim 3 (depends on 2) An apparatus as claimed in claim 2 wherein said vapor pump is an electrically driven pump and further comprising circuitry to operate said vapor pump at a speed to pump vapor at a rate comparable to said liquid flow rate as the ordinary vapor flow rate. ### Claim 4 (depends on 1) An apparatus as claimed in claim 1 wherein said vapor impulsion means is a vapor pump and said vapor impulsion booster comprises circuitry to operate said vapor pump at a speed to pump vapor at a rate greatly in excess of said liquid flow rate early in the fueling operation. ### Claim 5 (depends on 1) An apparatus as claimed in claim 1 wherein said vapor impulsion means is a vapor pump and said vapor impulsion booster comprises circuitry to operate said vapor pump at a speed to pump vapor at a rate greatly in excess of said liquid flow rate, the excess being characterized by a fast rise time to a maximum and a gradual decrease. ### Claim 6 (depends on 5) An apparatus as claimed in claim 5 wherein the gradual decrease is a time-decaying exponential. ### Claim 7 (depends on 5) An apparatus as claimed in claim 5 wherein the gradual decrease is time-decaying and of a wave-form selected from the group consisting of exponential, transcendental, ramp, step, pulse or a combination thereof. ### Claim 8 (depends on 5) An apparatus as claimed in claim 5 wherein the gradual increase is modulated by sensing the volume of liquid pumped. ### Claim 9 (depends on 5) An apparatus as claimed in claim 5 wherein the gradual decrease is modulated by sensing the volume of vapor recovered. ### Claim 10 (depends on 1) An apparatus as claimed in claim 1 wherein said nozzle is bootless. ### Claim 11 (depends on 1) An apparatus as claimed in claim 1 wherein the ordinary vapor flow rate is proportional to the liquid flow rate. ### Claim 12 An apparatus for dispensing volatile liquid fuel with recovery of fuel vapors comprising a fuel delivery system including a fuel delivery line and a pump in said line to pump fuel there-along to a nozzle, a vapor recovery subsystem including a vapor return line from said nozzle and a vapor pump to induce vapor to flow through said vapor return line at a vapor flow rate comparable to the liquid flow rate through said fuel delivery line during most of a fueling operation, and a vapor impulsion booster circuitry to operate said vapor pump at a speed to pump vapor at a rate greatly in excess of said liquid flow rate early in a fueling operation, the excess being characterized by a fast rise time to a maximum and a gradual decrease to the rate comparable to the liquid flow rate through said fuel delivery line. ### Claim 13 A method of dispensing volatile liquid fuel with recovery of fuel vapors comprising pumping fuel through a fuel delivery line at a liquid flow rate to a nozzle, returning vapors along a vapor return line from the nozzle at an ordinary vapor flow rate through the fuel delivery line during most of a fueling operation, boosting the vapor flow rate above the ordinary vapor flow rate early in a fueling operation and subsequently returning the vapors at the ordinary vapor flow rate. ### Claim 14 (depends on 13) A method as claimed in claim 13 wherein said boosting step comprises pumping the vapor along the vapor return line while a valve in the vapor return line upstream of the vapor pump is closed and subsequently opening the valve and pumping the liquid, so that a reduced pressure is drawn in the vapor return line before liquid is pumped to provide a boost to the vapor flow rate above the ordinary vapor flow rate early in the fueling operation. ### Claim 15 (depends on 14) A method as claimed in claim 14 wherein said vapor returning step comprises electrically driving a vapor pump at a speed to pump vapor at a rate comparable to the liquid flow rate as the ordinary vapor flow rate. ### Claim 16 (depends on 13) A method as claimed in claim 13 wherein said vapor returning step comprises pumping the vapor with an electrically-driven vapor pump and said boosting step comprises supplying electrical signals to the vapor pump to operate the vapor pump at a speed to pump vapor at a rate greatly in excess of the liquid flow rate early in the fueling operation. ### Claim 17 (depends on 16) A method as claimed in claim 16 wherein said vapor returning step comprises pumping the vapor with an electrically-driven vapor pump and said boosting step comprises supplying electrical signals to the vapor pump to operate the vapor pump at a speed to pump vapor at a rate greatly in excess of the liquid flow rate early in the fueling operation, the excess being characterized by a fast rise time to a maximum and a gradual decrease. ### Claim 18 (depends on 17) A method as claimed in claim 17 wherein the gradual decrease is a time-decaying exponential. ### Claim 19 (depends on 17) A method as claimed in claim 17 wherein the gradual decrease is time-decaying and of a wave-form selected from the group consisting of exponential, transcendental, ramp, step, pulse or a combination thereof. ### Claim 20 (depends on 17) A method as claimed in claim 17 wherein the gradual decrease is modulated by sensing the volume of liquid pumped. ### Claim 21 (depends on 17) A method as claimed in claim 17 wherein the gradual decrease is modulated by sensing the volume of vapor recovered. ### Claim 22 (depends on 13) A method as claimed in claim 13 wherein said fuel pumping step comprises pumping to a bootless nozzle. ### Claim 23 A method of dispensing volatile liquid fuel with recovery of fuel vapors comprising pumping fuel through a fuel delivery line at a liquid flow rate to a nozzle, pumping vapor with an electrically-driven vapor pump along a vapor return line from the nozzle at a vapor flow rate comparable to the liquid flow rate through the fuel delivery line during most of a fueling operation, and supplying electrical signals to the vapor pump to operate the vapor pump at a speed to pump vapor at a rate greatly in excess of the liquid flow rate early in the fueling operation, the excess being characterized by a fast rise time to a maximum and a gradual decrease. ### Claim 24 (depends on 16) A method as claimed in claim 16 wherein said vapor returning step comprises pumping the vapor with an electrically-driven vapor pump and said boosting step comprises supplying electrical signals to the vapor pump to operate the vapor pump at a speed to pump vapor at a rate greatly in excess of the liquid flow rate early in the fueling operation, the excess being characterized by a fast rise time to a maximum. ### Claim 25 (depends on 1) An apparatus as claimed in claim 1 wherein the ordinary vapor flow rate is comparable to the liquid flow rate. ### Claim 26 (depends on 13) A method as claimed in claim 13 wherein said returning vapors step comprises returning vapors at an ordinary vapor flow rate comparable to the liquid flow rate.