REDUNDANT LIP SEAL FOR VALVE
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of United States Provisional Application Serial
No. 61/677,245, filed July 30, 2012, the disclosure of which is incorporated herein by reference
in its entirety.
TECHNICAL FIELD
[0002] The present teachings relate to valve seals, including a lip structure for a valve
seal.
BACKGROUND
[0003] Valves, such as inline check valves or other valves, may include sealing structures
between two valve components to prevent leakage of fluid and/or vapor. In fuel tank
applications, for example, the seal prevents fuel from leaking between layers or to the
atmosphere. However, various conditions may weaken the sealing capabilities of the seal. For
example, high internal pressures in the valve and/or a high differential between the pressures
inside and outside the valve may cause leakage. Contamination, flash, or other debris on the
sealing surface may also compromise the seal.
SUMMARY
[0004] A valve assembly is provided that is suitable for use in a fuel fill line. The valve
assembly may include a housing having a flange that surrounds the housing. A weld foot can be
molded over at least a portion of the flange. A lip seal may be disposed between the fiange and
the weld foot. The lip seal includes a first lip and a second lip that may both be contact with a
surface on one of the fiange and the weld foot.
[0005] Various aspects of the present teachings will become apparent to those skilled in
the art from the following detailed description of the embodiments, when read in light of the
accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] Embodiments of the invention will now be described, by way of example, with
reference to the accompanying drawings, wherein:
[0007] FIG. 1 is a schematic section view of a valve having a redundant lip seal
according to one aspect of the teachings;
[0008] FIG. 2 is a close-up schematic view of a portion of the valve in FIG. 1; and
[0009] FIG. 3 is a closer schematic view of a portion of the valve in FIG. 1.
DETAILED DESCRIPTION
[0010] Reference will now be made in detail to embodiments of the present disclosure,
examples of which are described herein and illustrated in the accompanying drawings. While the
invention will be described in conjunction with embodiments, it will be understood that they are
not intended to limit the invention to these embodiments. On the contrary, the invention is
intended to cover alternatives, modifications and equivalents, which may be included within the
spirit and scope of the invention as defined by the appended claims.
[0011] The teachings herein illustrate a valve seal having improved sealing capabilities.
FIG. 1 is a representative or schematic section view of a valve 10 incorporating a lip seal 12
according to one aspect of the teachings. The lip seal 12 may be disposed between a flange 14
surrounding the valve 10 and a weld foot 16 designed or configured to be weldable onto a fuel
tank. In an aspect of the teachings, the weld foot 16 may be overmolded onto a valve body 18.
The valve body 18 may include an interlock surface 20 that, in conjunction with the weld foot
16, may create a labyrinth leak path that makes it difficult for fluid or vapor to escape the valve
10 and may also make the valve 10 resistant to delamination.
[0012] As generally illustrated in FIG. 2, a seal ring 19 may be coupled to the lip seal 12
to provide more secure interlocking between the lip seal 12 and the weld foot 16. The
configuration may further improve leak-prevention robustness by, for example, preventing the
lip seal 12 from being dislocated or deformed during an overmolding process. In an aspect of the
teachings, the seal ring 19 may be comprised of metal. However, with embodiments, the seal
ring 19 may also be comprised of other appropriate rigid materials, such as, for example, a
plastic. Moreover, the seal ring 19 may also have a series of through holes, which for some
embodiments or applications may mechanically hold the lip seal 1 in place comparatively better
than a smooth surface and/or an adhesive between the seal ring 19 and the lip seal 12.
[0013] In embodiments, the lip seal 12 may have first and second lips 30, 32 that face
different directions. In an aspect of the teachings, first and second lips 30, 32 may face opposite
directions so that the lip seal 12 blocks fluid or vapor from moving past the lip seal 12 regardless
of the direction of the pressure differential. This can better ensure a secure seal even when the
valve 10 is tipped. The first and second lips 30, 32 can also provide a more robust labyrinth leak
path and provide a backup seal in case debris compromises the sealing capabilities of one of the
lips 30, 32. When a weld foot 16 is formed onto the flange 14, the lips 30, 32 deflect against the
flange 14 as the lip seal 12 is compressed. In one aspect of the teachings, the flange 14 may
include a shelf or step. With such a configuration, the seal ring 19 can be located against the
shelf or step and the lips 30, 32 can deflect against the shelf or step to maintain uniform
compression.
[0014] Although the illustrated lip seal 12 shows the lips 30, 32 deflecting in different
directions, the lips 30, 32 may be designed to deflect in the same direction without departing
from the scope of the disclosure. The material used to manufacture the lip seal 12 can be, for
example and without limitation, a low-permeability elastomer with a very high melting
temperature so that the lip seal 12 can withstand the temperatures and pressures of an
overmolding process.
[0015] The valve 10 may, if desired, be manufactured using a unique overmolding
process. In an embodiment, the overmolding process may contact the seal ring 19 at multiple
places to hold the seal ring 19 in place more securely and perhaps also more evenly.
[0016] Alternatively, or in addition, the overmolding process may incorporate a floating
steel ring inside the tooling. In an embodiment, the steel ring may be supported by high biasing
force springs, such as engine valve springs, against a plurality of stops in the mold. When
molten, pressurized plastic enters the mold, the floating steel ring may act like a piston and may
be compressed against the springs by the plastic. As the plastic cools, shrinks, and hardens, the
springs can push back and compress the plastic to prevent voids from forming.
[0017] As a result, the redundant lip seal structure 1 can prevent leaking regardless of
the differential between the pressure inside the valve 10 versus outside the valve 10. Moreover,
the redundant lip seal 1 can provide extra sealing surfaces to improve its sealing capabilities,
even if the lip seal 12 experiences contamination or flash on its sealing surface and/or high
pressure operating conditions.
[0018] It will be appreciated that the above teachings are merely exemplary in nature and
is not intended to limit the present teachings, their application or uses. While specific examples
have been described in the specification and illustrated in the drawings, it will be understood by
those of ordinary skill in the art that various changes may be made and equivalents may be
substituted for elements thereof without departing from the scope of the present teachings as
defined in the claims. Furthermore, the mixing and matching of features, elements and/or
functions between various examples is expressly contemplated herein so that one of ordinary
skill in the art would appreciate from this disclosure that features, elements and/or functions of
one example may be incorporated into another example as appropriate, unless described
otherwise, above. Moreover, many modifications may be made to adapt a particular situation or
material to the teachings of the present disclosure without departing from the essential scope
thereof. Therefore, it is intended that the present teachings not be limited to the particular
examples illustrated by the drawings and described in the specification as the best mode
presently contemplated for carrying out the teachings of the present disclosure, but that the scope
of the present disclosure will include any embodiments falling within the foregoing description
and the appended claims.
CLAIMS
What is claimed:
1. A valve assembly for use in a fuel fill line, the valve assembly comprising:
a housing including a flange that surrounds the housing;
a weld foot molded over at least a portion of the flange; and
a seal disposed between the flange and the weld foot,
wherein the seal includes a first lip and a second lip, and the first lip and second lip are
both in contact with a surface on one of the flange and the weld foot.
2. The valve assembly of claim 1, wherein the housing includes an interlock surface,
and a portion of the weld foot is molded over the interlock surface.
3. The valve assembly of claim 1, wherein the seal is coupled to a seal ring, and the
seal ring is configured to provide support for the seal.
4. The valve assembly of claim 3, wherein the seal ring includes a plurality of
through holes for mechanical engagement between the seal and the seal ring.
5. The valve assembly of claim 3, wherein the seal and the seal ring are over-molded
between the flange and the weld foot.
6. The valve assembly of claim 3, wherein the flange forms a stepped portion, and
the seal ring engages the stepped portion to maintain deflection of the first and second lips of the
seal against the flange.
7. The valve assembly of claim 1, wherein the first lip of the seal extends in a first
direction and the second lip of the seal extends in a second direction.
8. The valve assembly of claim 7, wherein the first lip of the seal extends in a
generally opposite direction than the second lip of the seal.
9. The valve assembly of claim 1, wherein the first and second lips of the seal are in
contact with a surface of the flange.
10. A check valve assembly for use in a fuel fill line, the check valve assembly
comprising:
a housing including a flange that surrounds the housing;
a weld foot that is secured over a portion of the housing and the flange; and
a lip seal disposed between the flange and the weld foot,
wherein the lip seal has a first lip and a second lip, and the first lip and the second lip are
spaced apart from one another and are in contact with a surface of the flange.
11. The check valve assembly of claim 10, wherein the housing includes an interlock
surface and a portion of the weld foot is molded over the interlock surface.
12. The check valve assembly of claim 10, wherein the lip seal is coupled to a seal
ring that provides support for the lip seal.
13. The check valve assembly of claim 12, wherein the seal ring includes a plurality
of through holes for mechanical engagement between the lip seal and the seal ring.
14. The check valve assembly of claim 12, wherein the lip seal and the seal ring are
over-molded between the flange and the weld foot.
15. The check valve assembly of claim 12, wherein the flange forms a stepped
portion, and the seal ring engages the stepped portion to maintain uniform deflection of the first
and second lips of the lip seal against the flange.
16. The check valve assembly of claim 1, wherein the first lip of the lip seal extends
in a first direction and the second lip of the lip seal extends in a second direction.
17. The check valve assembly of claim 16, wherein the first lip of the lip seal extends
in a generally opposite direction than the second lip of the lip seal.
18. A check valve assembly comprising:
a housing having a flange that surrounds the housing, and the flange defines a stepped
portion;
a weld foot molder over at least a portion of the flange; and
a lip seal including a first lip and a second lip, and the lip seal is coupled to a seal ring,
wherein the lip seal is disposed between the flange and the weld foot such that the seal
ring engages the step portion of the flange and the first and second lips are in contact with a
surface of the flange.
19. The check valve assembly of claim 18, wherein the housing includes an interlock
surface and a portion of the weld foot is molded over the interlock surface.
20. The check valve assembly of claim 18, wherein the first lip of the lip seal extends
in a first direction and the second lip of the lip seal extends in a second direction that is generally
opposite the first direction.