Siphonable check valve and method of making same

[0001] The present invention relates to filler tubes for motor vehicle fuel tanks and the problems related to controlling emission of fuel vapors therefrom during refueling operations.

[0002] Currently, it is required to provide for controlling the emission to the atmosphere of fuel vapor during refueling when a nozzle has been inserted into the fuel tank filler tube for discharging fuel into the filler tube. Currently, vehicle fuel tank filler tubes are designed to have a baffle in the filler tube with a flapper valve having aperture sized to closely interfit the fuel discharge nozzle and thereby minimize the opening available for fuel vapor emission during refueling.

[0003] However, it is now required to provide for withdrawal of fuel from the tank through the filler tube in the event that in service removal of the tank is required after the initial assembly of the vehicle. The withdrawal of fuel from the vehicle tank is usually accomplished by insertion of a siphoning hose through the filler tube into the tank. However, where a check valve has been employed in the filler tube downstream of the flapper valve to prevent overfill or liquid escape during vehicle rollover it has been found quite difficult to push the end of the siphon hose through the check valve to the bottom of the fuel tank once the hose has entered the tank. It has been experienced that the end of the siphon hose lodges in the check valve.

[0004] It has thus been desired to provide a way of incorporating a check valve in a fuel tank filler tube such that it is easy to push a siphoning hose into the filler tube and through the check valve for withdrawal of fuel from the tank in the event that it is necessary to remove the tank from the vehicle for service. It has further been desired to provide such a siphonable filler tube check valve arrangement which is sufficiently low in manufacturing costs to be competitive in high volume automotive production and which is easy to assemble and install into the tank filler during manufacture of the tank and assembly into the vehicle.

[0005] The present invention provides a filler tube assembly for attachment to a vehicle fuel tank which employs a tubular body having an annular valve seat therein with a poppet valve therein which is biased to the closed position against the seating surface provided about the interior of the body. The tubular body has radially inwardly extending tapered ribs or vanes provided on the inlet end of the body upstream of the valve seating surface for diverting a siphoning hose laterally; and, the surface of the poppet is tapered to divert the end of the siphoning hose laterally through an aperture formed in the side of the filler tube body downstream of the valve seating surface. The poppet valve includes a resilient seal integrally formed thereon which provides for sealing against the valve seating surface with a minimum of bias force and thus minimum resistance to opening is encountered upon insertion of a refueling nozzle or siphoning hose therein.

[0011] Referring to FIGS. 1 and 2, the valve assembly of the present invention is indicated generally at 10 and includes a tubular housing or body 12. The upper end of the body 12 has annular barbs 14 provided on the outer surface thereof for connection to the lower end of the tank filler tube (not shown). A sealing ring 16 is provided below the barbs 14 to provide a positive seal between the upper end of the body 12 and the filler tube.

[0012] The inner periphery of the body 12 adjacent the upper end has a plurality of circumferentially spaced radially inwardly extending ribs 20 preferably, by not necessarily formed integrally therewith, with each of the ribs having the inward edge thereof tapered in an axial direction as shown in FIG. 2. The radially inward edges of the ribs 20 define, in cooperation with portions 22 of the opposite side of the inner periphery of the body 12, a reduced cross-section opening which is offset from the center of the body. This offset opening is operative to receive therein the end of a siphoning hose (not shown) when such is inserted through the unshown filler tube and upper open end of the body 12. Upon insertion of such an unshown siphoning hose, the tapered edges of the ribs 20 serve to deflect or cam the end of the siphoning hose into the offset opening.

[0013] An annular valve seating surface 24 is formed about the inner periphery of the body 14 at a location below, i.e. downstream of the ribs 20. The tubular body 12 has at least one and preferably a plurality of circumferentially spaced apertures 18 formed in the side walls of the body downstream of the annular valve seating surface 24, which apertures 18 are of sufficient size to provide adequate clearance for a siphoning hose to extend outwardly therethrough. A moveable poppet 26 is disposed for sealing against the valve seating surface 24; and, the poppet is biased in an upward direction by a spring 28 having its upper end registered against the undersurface of the poppet. The lower end of spring 28 is retained by a suitable retainer 30 disposed in the lower end of the housing or body 12 and retained therein by barbs 31 engaging corresponding slots 33 appropriately located in the body.

[0014] Poppet 26 has a pilot 32 formed thereon which extends downwardly within the spring and through an aperture 34 provided in the retainer 30 for guiding movement of the poppet. The upper end of the poppet 26 has a tapered surface 36 which serves to deflect the end of a siphoning hose (not shown) outwardly or laterally upon insertion of the end of the hose into contact with tapered surface 26 and effecting downward movement of the poppet to the position shown in dashed outline in FIG. 2.

[0015] Referring to FIGS. 3 and 4, the poppet 26 has an annular resilient seal 38 formed thereon preferably by molding over the poppet. Seal 38 has integral portions thereof denoted by reference numeral 40 in FIGS. 3 and 4 extending through a plurality of circumferentially spaced aperture 42 formed in an annular shoulder in the poppet. Seal 38 has an annular flange 44 formed integrally with portions 40 and extending about the undersurface 46 of the shoulder for retaining the seal 38 on the poppet. In the presently preferred practice, the seal 38, portions 40 and flange 44 are formed integrally on the poppet by placing the poppet in a mold (not shown) and overmolding with a suitable elastomeric material.

[0016] The body 12, poppet 26 and retainer 30 may be formed of any suitable engineered resinous material which has electrostatic dissipative properties. In the present practice of the invention polythalamide (PTA) material fractionally filled with particulate glass and carbon has been found to be satisfactory; however, other resinous materials and particulate fill may be employed.

[0017] The present invention thus provides a one-way shutoff valve for incorporation between a filler neck and a fuel tank for preventing escape of fuel during sloshing or vehicle tilting or rollover and provides for opening by insertion of a flexible siphoning hose into the filler neck and thereby permits the hose to enter the tank. The present invention employs deflector vanes in the interior of the tubular valve body upstream of the poppet; and, upon opening of the poppet by the insertion of a siphoning hose, the end of the hose is deflected by the surface of the poppet outwardly through apertures formed in the side wall of the valve body.

[0018] Although the invention has hereinabove been described with respect to the illustrated embodiments, it will be understood that the invention is capable of modification and variation and is limited only by the following claims.