Vapor seal for fuel tank filler tube

Abstract

The invention relates to a vapor seal member adapted to be received within the filler neck of a fuel tank. Normally, such filler necks are cylindrical in shape and sufficiently long to receive a corresponding discharge tube section of a fuel dispensing nozzle. The filler tube further includes a terminal rim at the outer edge to removably receive a closure cap. The vapor seal member includes a peripheral lip which firmly engages said terminal rim of said filler tube. A central resilient segment of the seal member defines an access opening adapted to slidably receive the discharge tube of the nozzle whereby to form an annular vapor tight seal with the latter and thus avoid passage of fuel vapors from the tank.

Description

BACKGROUND OF THE INVENTION

During the fueling of a motor vehicle such as an automobile, boat, airplane or the like, a vaporizable fuel in liquid phase is normally introduced to the fuel tank in a pressurized stream.

As liquid fuel is introduced to the partially empty tank, residual vapors from the latter will normally be forced from the tank, usually through the filling spout. Said vapors will thereafter pass directly into the atmosphere unless otherwise collected or treated.

It is known that in relatively congested areas the continuous passage of vapor fumes into the air can contribute toward pollution of the atmosphere. Further, such fumes when passed into a confined space can accumulate and constitute an explosive environment.

Toward protecting the environment from this possible problem, states and municipalities have attempted to legislate against air pollution with varying degrees of success. As a matter of practicality, it is becoming more essential that with the increased use of volatile automotive fuels in vehicles utilizing internal combustion engines, some form of compatible fuel system must be developed. Such a system ideally must either confine the fuel in a completely closed circuit, or otherwise preclude passage of fuel vapors from the system.

In the arrangement presently disclosed, the normal automotive vehicle will be utilized to illustrate the novel fuel system. In said arrangement the automotive gas tank is carried at some point within the vehicle such that the filler spout inlet protrudes at a point where it is readily accessible to a fuel dispensing nozzle.

To avoid vapor leakage from the fuel tank by way of the open filler spout, the latter is provided with means to sealably engage a filling nozzle during the tank filling operation. Thus, insertion of said dispensing nozzle into the filler spout immediately forms a vapor tight annular seal to in effect define a substantially confined fuel system.

Thereafter, with the progressive filling of the fuel tank, residual vapors can be controllably carried from the tank to be collected or condensed, without loss of said vapors to the atmosphere.

DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates the invention, in partial cross section, in conjunction with a fuel dispensing nozzle prior to engagement of the nozzle with the tank filler spout.

FIG. 2 is a segmentary view in partial cross section and on an enlarged scale showing a fuel tank filler spout.

FIG. 3 is an enlarged segmentary section showing a discharge tube in registry with an adapter during a fuel transfer operation.

FIG. 4 is an end view with part broken away, of FIG. 3.

Referring to the drawings, a vehicle fuel tank 10 of the type contemplated, includes a generally closed metallic receptacle. The latter is supported on the vehicle such that it can be readily filled, and communicated with the vehicle's engine. Said tank 10 thus includes an elongated filler spout or fuel conduit 11 that is communicated at one end with the tank interior, and so formed to terminate at a point of the vehicle exterior where it may be removably engaged by a fuel dispensing nozzle 12.

As shown in FIG. 1, fuel dispensing nozzle 12 includes in essence a means such as a flexible hose 13 communicating said nozzle with a pressurized source of a volatile fuel. A control valve within the nozzle, although not presently shown, is manually operable to regulate the flow of fuel from the source thereof into an elongated, slightly curved discharge tube 14. The control valve, in the normal manner, is actuated through a manually adjusted lever 16 such that an operator can vary the volume of fuel flow, or fix said lever 16 to permit a steady, continuous flow.

In fuel dispensing nozzles of this type, means are normally incorporated for automatically discontinuing fuel flow at such time as the tank becomes filled and liquid rises within the filler spout 11. Also in fuel systems of the type disclosed, venting means is communicated with tank 10 or with filler spout 11. Vapors are thereafter conducted to a closed receptacle, or preferably condensed into liquid form and passed to the pressurized fuel source to be recirculated into tank 10.

While not presently illustrated, such vapor collecting means can be through nozzle 12 and associated condensing apparatus.

Filler spout 11 is normally cylindrical in general configuration, the remote end thereof being so sloped as to receive a fuel nozzle and to hold the latter in place during the fuel transfer operation. In the instant arrangement, filler spout 11 extends in a generally upward direction having an inlet 17 at the remote end which includes an inwardly turned rim or lip 18. The latter embodies slots or the like on the facing edge, formed therein to accommodate corresponding locking tabs as will be herein noted.

A cap 19 comprises in essence a removable closure means adapted to be aligned with the upper end of said filler spout 11. A partial rotation of the cap fastens the latter into place whereby to avoid leakage of either liquid or vapors from the tank. Said cap can also be provided with emergency vapor venting means such as an opening or valve whereby to avoid pressure build-up in tank 10.

In the normal filling of a vehicle fuel tank 10, without the use of the present sealing means, cap 19 is rotatably disconnected from its fixed position and removed from the filler spout inlet 17. At this point of the operation, fuel vapors confined in the tank will be free to pass to the atmosphere. However, with introduction of the fuel nozzle discharge tube 14 into filler spout 11, entry of the liquid fuel to the latter will cause residual vapors to rise up along the filler spout and pass into the atmosphere.

As shown in the present arrangement, toward overcoming this undesired vapor discharge during the filling period, the terminal or remote end of filler spout 11 is provided with an adapter member 21.

Adapter member 21 includes in essence a relatively elongated central section 22, having an enlarged opening 23 at one end, and a constricted opening 24 at the other or inner end. Said respective openings 23 and 24 are connected by a frusto conical or tapered portion 26 that defines a smoothly curved surface.

Central section 22 is designed to slidably receive the inserted nozzle discharge tube 14 which is guided along the tapered portion 26 toward the smaller or sealing segment at opening 24. The latter, constituting means forming said constricted opening, is of sufficient size or diameter to slidably engage the external walls of discharge tube 14. Said opening 24 is thus outwardly urged, or radially expanded during insertion of said discharge tube 14. The walls of said section 24 are sufficiently resilient to maintain a close fit and to define an annular seal about the said discharge tube periphery. The connection thereby defines a barrier to passage of vapors from fuel tank 10.

Preferably, the entire central member 22 is formed of a material sufficiently resilient to freely pass the nozzle, and to form a vapor tight seal therewith. Said material is necessarily not only durable, but resistant to deterioration when contacted with the volatile fuel, or with other liquids that might be added to or introduced to fuel tank 10. One form of such material includes a thermal plastic such as Neoprene, Nitrile, Viton, Buna N or the like which, under a wide range of atmospheric temperatures, will maintain their resilient characteristics to form the necessary annular seal as discharge tube 14 is repeatedly registered therewith.

To maintain the integrity of the entire central segment 22, the walls thereof can be provided adapter, or more, and preferably a plurality of stiffener strips 27. The latter can be moulded directly into the walls of the central member extending from the inlet end 23, to the smaller discharge opening 24. Said stiffeners, however, can also be formed along the exterior surface of member 21 whereby to achieve the necessary strengthening of the unit.

To maintain adapter 21 in its preferred position within the upper end of a filler spout 11, said adapter is provided with a ring 28 which is fastened along a lateral engaging surface to a corresponding wall of central section 22. Said ring 28 includes an upstanding annular rim 29, so formed about its periphery to engage the corresponding engaging lip 18 of filler spout 11 in a forced or tight fit. Thus, adapter 21 is urged through accommodating slots at the filler spout remote end, and said adapter 21 can be rotated much in the manner of a nozzle cap to assume a relatively fixed position. Further the placing of ring 28 is such as to remain fixed even though removably connected to cap 19.

An extended portion of said ring 28 further includes a peripheral segment 31, which is presently shown inwardly formed, but could be formed to define a circular seat 32 to receive and lock the cap 19. Said receiving seat 32 includes peripherally spaced openings or slots 33, which are so shaped and spaced apart with respect to each other, to receive corresponding locking tabs 34 depending from cap 19. Thus, when said tabs 34 are properly inserted into the respective slots, and the cap 19 is rotated into its locked position, the cap will form a vapor tight closure along gasketed surface 36.

As shown in FIG. 3, nozzle 12 is urged into adapter 21 such that a substantial length of tube 14 is within spout 11. Adapter 21 will as shown be deformed primarily at constricted opening 24. However, the weight of the nozzle will cause the latter to drop, whereby the outer end of tube 14 will engage the inner wall of spout 11.

As further shown, the upper end of tapered section 22 is provided with one or more, and preferably a series of valves 37. The latter include a movable element that is displaceable when subjected to excessive pressure in the tank. Therefore in the event that fuel vapors are not removed from tank 10 at a sufficiently rapid rate, venting through valves 37 will avoid an undesirable pressure build-up within the tank.

Referring to FIG. 3, during the time when fuel dispensing nozzle 12 is registered within adapter 21, the friction hold between the segment 24 of the latter, and nozzle discharge tube 14, will normally be sufficient to retain the nozzle in its preferred position. Thereafter, in the normal mode of operation, fuel flow will be commenced by actuation of lever 16 and continued into tank 10. Vapors are forced from the tank and removed by venting means to be stored or condensed at the termination of the fuel filling operation.

Tank 10 thus can be relatively full of liquid with but a small residual volume of vapor remaining within the filler spout 11. As dispensing nozzle 12 is withdrawn, filler spout 11 will be momentarily exposed to the atmosphere resulting in a minor amount of fuel vaporization and passage of said vapors to the atmosphere. However, such vapor passage will be terminated upon the replacement of nozzle cap 19 in its desired position in engagement with adapter 21.

Other modifications and variations of the invention as hereinbefore set forth may be made without departing from the spirit and scope thereof, and therefore, only such limitations should be imposed as are indicated in the appended claims.

Claims

I claim:

1. In a vehicle fuel tank for a closed fuel transfer system wherein a volatile fuel is transferred from a storage means therefor to a vehicle tank by way of a dispensing nozzle removably communicated with said vehicle tank, the latter having a filler spout adapted to receive a discharge tube of said dispensing nozzle, the improvement therein for establishing a disconnectable vapor tight seal while said dispensing nozzle and filler spout are in engagement comprising:

an elongated resilient wall adapter having an inlet at one end thereof, and being fixedly retained by a circular neck connected to said filler spout to prevent axial movement therebetween, said adapter having a sealing portion disposed within said filler spout thereby defining an expandable longitudinal passage, the latter being outwardly expandable to form a vapor tight annular seal about said nozzle discharge tube while being spaced from the inner wall of said filler spout thereby defining an annular opening extending the length of said sealing portion when said discharge tube is removably registered in said longitudinal passage, and said adapter being laterally displaceable along said sealing portion into said annular opening to allow a limited degree of pivotal movement of said dispensing nozzle of circular neck when said nozzle discharge tube is so registered within said filler spout,

whereby volatile fuel vapors forced from said vehicle tank during the filling operation will be retained in said closed fuel system.

2. In an apparatus as defined in claim 1, wherein said adapter expandable longitudinal passage includes; an inlet opening having a substantially larger diameter than said elongated sealing portion of said adapter.

3. In an apparatus as defined in claim 1, wherein said expandable longitudinal passage includes longitudinally aligned; stiffener means formed therein to maintain the shape of said longitudinal passage.

4. In an apparatus as defined in claim 1, wherein said adapter includes; a tapered segment having an enlarged inlet end, forming said expandable longitudinal passage.

5. In an apparatus as defined in claim 1, wherein said adapter includes; a ring depending from the adapter inlet end, and means on said ring to sealably engage said closure cap.

6. In an apparatus as defined in claim 1, wherein said adapter elongated sealing portion is formed of a fuel resistant thermal elastic material, adapted to yield outwardly upon registration of said discharge nozzle therein, and to maintain a close annular seal thereabout during the tank filling operation.

7. In an apparatus as defined in claim 1, including valve means in said resilient wall adapter , being displaceable in response to internal pressure to an open position whereby to vent excessive pressure accumulation within said fuel tank.