Fluid handling – Line condition change responsive valves – Direct response valves
Reexamination Certificate
2000-03-23
2001-07-03
Chambers, A. Michael (Department: 3748)
Fluid handling
Line condition change responsive valves
Direct response valves
C137S521000, C137S592000
Reexamination Certificate
active
06253788
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention concerns a check valve for a filler pipe for the filling of a motor-vehicle fuel tank, having a housing fixed in the interior of the pipe and a movably mounted flap closure which is opened by the inflowing fuel and closes again automatically.
Various types of check valves can be fitted in filler pipes for the filling of a motor-vehicle fuel tank. A check valve is intended to prevent the fuel from rising back up into the filler pipe and escaping from the filling opening, as a result of the positive pressure occurring in the tank during filling, when the filling nozzle is switched off. The check valves do not have to provide a completely tight seal, but must oppose the return flow with adequate resistance, with the result that there is no undesired and troublesome escape of fuel from the filler pipe after filling.
Most of the check valves known for this purpose have spherical or conical valve bodies which, under the force of a weak spring, are directed against the filling flow and are opened by the inflowing fuel. The valves automatically close the opening when the inflowing fuel breaks off. There are configurations which are provided with elastomeric seals and also configurations which provide a seal only by resting on the valve seat. All of these known valves have the disadvantage that the fuel flow undergoes a sharp diversion. In the case of many configurations, it is only possible for the valves to be fitted at the end of the filler pipe or in a corresponding widening of the pipe, since the deflected fuel flow takes up space laterally. The fuel is subjected to great turbulence by the deflection, which leads to outgassing and hinders filling of the tank. The increased amount of gas must also be passed either into the ambient air or into active carbon filters, as are required for example in the USA, which entails further disadvantages.
Check valves of the type mentioned at the beginning which have a valve flap swivel-mounted laterally on the housing and held in the closed position either by its own weight or else under the force of a spring are also known. It is also the case with these valves that the opening and closing is brought about by the flow of fuel, as described above. In the case of these valves, the valve flaps have a much smaller diameter than corresponds to the inside diameter of the pipe, in order to be able to swing open. The mounting of the valve flap and the internal valve seating considerably reduce the cross-sectional area through which flow can pass, however, and the opened flap also causes great turbulence, which has the consequence of the outgassing described above.
It is a principal object of the present invention to design a check valve of the type described above wherein significantly less turbulence and disturbance of the flow of the fuel occurs during filling than is the case with known valve configurations, and consequently no or only insignificant outgassing takes place.
SUMMARY OF THE INVENTION
The foregoing object is achieved according to the present invention wherein the flap closure comprising two valve flaps which are movably mounted jointly in the region of the center of the housing in a removable manner.
Check valves configured according to the invention therefore have two valve flaps for an opening and closing movement which are mounted in the region of the center of the filler pipe. In their open position, the valve flaps can consequently assume an attitude which is very favorable in terms of flow dynamics. The fuel is therefore scarcely deflected and no significant turbulence occurs. Check valves designed according to the invention can also be fitted into filler pipes configured without widenings (as described above) and at the same time retain their advantages.
The movable mounting of the valve flaps on the housing is of a particularly simple form if there is provided centrally on the housing a bearing part which passes transversely through said housing and is at least essentially closed at its region facing the filling opening of the filler pipe. It is of advantage here if this region is configured with a contour that is favorable in terms of flow dynamics.
According to a preferred embodiment of the invention, the valve flaps are produced from a material which largely supports their mobility for assuming an open position or a closed position. This opens up a number of possibilities for the configuration and arrangement of the valve flaps.
Precisely in the case of such an embodiment it is possible to design the valve flaps as component parts of a double flap of an integral configuration.
In this case, the valve flaps may consist of a flexible material, in particular of a flexible film. Precisely such a material offers very little opening resistance.
In the case of this first embodiment, the flexible valve flaps can be clipped into snap-in recesses or the like of the bearing part by means of a holder, which is provided with snap-in elements guided through the valve flaps.
In the case of a second possible embodiment, where the material brings about the required mobility for assuming the open position and for returning into the closed position, the valve flaps are produced from spring steel sheet or a comparable material.
The arrangement or mounting of the valve flaps can be carried out on the bearing part of the housing in a space-saving and simple way. For this purpose, the valve flaps can, for example, be arranged on the bearing part by means of foot parts or by means of one foot part connecting them, the foot part or parts being held on the housing by a cross bar.
In the case of a third embodiment, where particularly little space is available for the mounting of the valve flaps, the valve flaps are swivel-mounted on the bearing part.
A particularly simple configuration of a swivel mounting provides that the valve flaps are mounted on the bearing parts in the manner of a hinge. This also promotes a design of the bearing part that is favorable in terms of flow dynamics. In the case of this embodiment of the invention, the valve flaps may be molded parts, in particular molded plastic parts.
In the case of this embodiment, it may be advantageous to provide a spring acting on the valve flaps to support a movement of the valve flaps into the closed position.
In the case of a preferred configurational variant of the invention, the extent of the movement of the valve flaps required for opening or closing is kept small, in that the valve seats for the valve flaps are formed by a V-shaped incision in the housing, the tip of which points toward the filling opening. This design is of advantage in particular in the case of those embodiments where the valve flaps are movable as a consequence of their material properties and their mounting. In this case, an angle between the two valve seats of the order of magnitude of 90° is also particularly favorable.
REFERENCES:
patent: 2292003 (1942-08-01), Yant et al.
patent: 3312237 (1967-04-01), Mon et al.
patent: 4230148 (1980-10-01), Ogle, Jr.
patent: 4774981 (1988-10-01), Mizusawa
patent: 4896695 (1990-01-01), Pysh
patent: 5245956 (1993-09-01), Martin
patent: 5381821 (1995-01-01), Muddiman
patent: 5518026 (1996-05-01), Benjey
patent: 6098656 (2000-08-01), Farina
patent: 794511 (1958-05-01), None
Bachman & LaPointe P.C.
Chambers A. Michael
McShane Thomas L.
Tesma-Motoren-und Getriebetechnik Ges. m.b.H.
LandOfFree
Check valve for use in a filler pipe for filling a fuel tank does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Check valve for use in a filler pipe for filling a fuel tank, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Check valve for use in a filler pipe for filling a fuel tank will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2532086