U.S. patent application number 10/178678 was filed with the patent office on 2003-12-25 for vented fuel tank cap.
Invention is credited to Grybush, Anthony F., Steffes, Kevin D..
Application Number | 20030234254 10/178678 |
Document ID | / |
Family ID | 29734749 |
Filed Date | 2003-12-25 |
United States Patent
Application |
20030234254 |
Kind Code |
A1 |
Grybush, Anthony F. ; et
al. |
December 25, 2003 |
Vented fuel tank cap
Abstract
A vented fuel tank cap for closing the filler neck portion of a
fuel tank for a small gasoline powered implement. The fuel tank cap
assembly includes a cap member having threads for removably
attaching the cap assembly to the fuel tank filler neck. The cap
member also includes a post depending from an interior of the cap
member. The cap assembly further including a gasket having an
annular rim surrounding a dome portion and an opening. The opening
of the gasket is disposed on the post and retained by a rib
protruding externally from the post. The gasket dome portion is
deformed by the rib so that the annular rim is held in contact with
the interior surface of the cap member. A vent path is provided
through the post to vent fuel vapors from below a lower surface of
the gasket, through a filter element captured between the gasket
dome and the interior surface of the cap member, through a groove
defined between the gasket annular rim and the interior surface of
the cap member, and out through a space defined between the threads
retaining the cap member to the filler neck.
Inventors: |
Grybush, Anthony F.; (Kiel,
WI) ; Steffes, Kevin D.; (Fond du Lac, WI) |
Correspondence
Address: |
BAKER & DANIELS
111 E. WAYNE STREET
SUITE 800
FORT WAYNE
IN
46802
|
Family ID: |
29734749 |
Appl. No.: |
10/178678 |
Filed: |
June 24, 2002 |
Current U.S.
Class: |
220/366.1 ;
220/303; 220/371 |
Current CPC
Class: |
B60K 15/0406 20130101;
B60Y 2200/225 20130101; B60K 2015/03236 20130101; A01D 34/001
20130101 |
Class at
Publication: |
220/366.1 ;
220/371; 220/303 |
International
Class: |
B65D 051/16 |
Claims
What is claimed is:
1. A vented fuel tank cap assembly, comprising: a cap member
including a circular cap portion and a downwardly depending skirt
portion, said skirt portion including an engagement portion for
removably attaching the cap assembly to a filler neck portion of a
fuel tank, said cap portion including a cylindrical post depending
from an interior of said cap portion, said post having at least one
rib extending exteriorly around at least a portion thereof; and a
gasket having an annular rim surrounding a dome portion and an
opening in said dome portion, wherein said opening fits around said
post and said rib retains said gasket to said cap member.
2. The vented fuel tank cap assembly of claim 1, further comprising
a porous filter element disposed between said dome portion of said
gasket and said interior of said cap portion, wherein said filter
element transmits fuel vapors and is generally impervious to liquid
fuel.
3. The vented fuel tank cap assembly of claim 2, wherein said rib
deforms said dome portion of said gasket compressing said filter
element between said dome portion and said interior of said cap
portion.
4. The vented fuel tank cap assembly of claim 1, wherein said
engagement portion comprises threads cooperating to retain the fuel
cap to said fuel tank while providing a vent path therethrough.
5. The vented fuel tank cap assembly of claim 1, further comprising
a vent path for venting gases between the fuel tank and the
atmosphere defined by said post from an end of said post opposite
said interior of said cap portion to a point between said dome
portion and said interior of said cap portion.
6. The vented fuel tank cap assembly of claim 5, wherein: said
annular rim contacts said interior of said cap portion; and at
least one vent path is defined between said annular rim and said
interior of said cap portion.
7. The vented fuel tank cap assembly of claim 5, wherein said post
comprises a tube and said vent path comprises a slot defined
through a wall of said tube.
8. A vented fuel tank cap assembly, comprising: a cap member
including a circular cap portion and a downwardly depending skirt
portion, said skirt portion including a nonsealing thread for
removably attaching the cap assembly to the filler neck portion,
said cap portion including a tubular post depending from an
interior of said cap portion, an interior surface of said tubular
post defining a first deflection surface and a first vent path; and
a gasket having an annular rim surrounding a dome portion and an
opening defined in said dome portion, said opening engaged around
said tubular post, said gasket and an exterior surface of said
tubular post defining a second deflection surface, said annular rim
contacting said interior of said cap portion and forming at least
one second vent path therebetween.
9. The vented fuel tank cap assembly of claim 8, wherein said first
vent path comprises a slot defined through a wall of said tubular
post.
10. The vented fuel tank cap assembly of claim 8, wherein said at
least one second vent path is formed by at least one radial groove
defined between an upper surface of said annular rim and said
interior of said cap portion.
11. The vented fuel tank cap assembly of claim 8, wherein said post
defines a rib protruding externally around a portion thereof, said
rib retaining said gasket to said cap member.
12. The vented fuel tank cap assembly of claim 8, further
comprising a porous filter element disposed between said dome
portion of said gasket and said interior of said cap portion,
wherein said filter element transmits fuel vapors and is generally
impervious to liquid fuel.
13. The vented fuel tank cap assembly of claim 12, wherein said rib
deforms said dome portion of said gasket, compressing said filter
element between said dome portion and said interior of said cap
portion.
14. A vented fuel tank cap assembly, comprising: a cap member
including a circular cap portion and a downwardly depending skirt
portion, said skirt portion including an engagement portion for
removably attaching the cap assembly to a filler neck portion of a
fuel tank, said cap portion including a post depending from an
interior of said cap portion; and a circular gasket having an
opening defined therethrough, an upper surface engageable with said
interior of said cap portion, and a lower surface opposite said
upper surface, said opening disposed around said post; said post
defining a first vent path for communication of gases adjacent said
lower surface with gases adjacent said upper surface.
15. The vented fuel tank cap assembly of claim 14, wherein said
post comprises a tube and said vent path comprises a slot defined
through a wall of said tube.
16. The vented fuel tank cap assembly of claim 14, wherein said at
least one second vent path is formed by at least one radial groove
defined between an upper surface of said annular rim and said
interior of said cap portion.
17. The vented fuel tank cap assembly of claim 14, wherein said
post defines a rib around an external portion thereof, said rib
retaining said gasket to said cap member.
18. The vented fuel tank cap assembly of claim 17, further
comprising a porous filter element disposed between said gasket and
said interior of said cap portion, wherein said filter element
transmits fuel vapors and is generally impervious to liquid
fuel.
19. The vented fuel tank cap assembly of claim 18, wherein: said
gasket further comprises a dome portion; and said rib captures said
filter element between said dome portion and said interior of said
cap portion.
20. The vented fuel tank cap assembly of claim 14, wherein said
engagement portion comprises threads cooperating to retain the fuel
cap to said fuel tank while providing a vent path therethrough.
21. In combination: a fuel tank having a fuel tank neck portion;
and a fuel tank cap having: a cap member including a circular cap
portion and a downwardly depending skirt portion, said skirt
portion including an engagement portion for removably attaching
said cap to said filler neck portion, said cap portion including a
tubular post depending from an interior of said cap portion, said
tubular post having at least one rib extending exteriorly around at
least a portion thereof; and a gasket having an annular rim
surrounding a dome portion and an opening in said dome portion,
wherein said opening fits around said tubular post and said rib
retains said gasket to said cap member.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention.
[0002] The present invention relates to fuel tank caps for closing
the filler neck of a fuel tank of a small internal combustion
engine, particularly to a vented fuel tank cap.
[0003] 2. Description of the Related Art.
[0004] Small implements having gasoline powered engines, such as
lawnmowers, garden tillers, snow blowers, sport vehicles,
electrical generators and the like, have fuel tanks attached. For
closing the fuel tank, a fuel tank cap is applied to the open end
of a filler neck connected to and extending from the fuel tank. The
fuel tank cap is commonly constructed to prevent escape of liquid
fuel from the fuel tank while, at the same time, permitting venting
of gases between the tank and the atmosphere.
[0005] One known fuel tank cap includes a generally dome-shaped
flexible gasket extending below the interior of the fuel tank cap.
The lower dome portion of the fuel tank cap includes holes
therethrough for venting of vapors. Additionally, sufficient
clearance is provided between internal threads on the fuel tank cap
and external threads on the filler neck to define a path for
venting of vapors. A narrow central post depends from the interior
of the fuel tank cap and through the gasket. Below the gasket and
vent holes, the central post also supports a baffle for deflecting
liquid fuel away from the gasket vent holes. However, an extra
manufacturing step is required to heat deform the end of the
central post so that it will retain the baffle and gasket, adding
expense and complexity to manufacturing.
[0006] Another known fuel tank cap includes a dome-shaped flexible
gasket having a central vent hole and an integral downward
depending tubular-shaped baffle around the vent hole which deflects
liquid fuel away from the vent hole. The gasket has an annular rim
that is retained by a matching annular notch in the fuel tank cap.
However, separation of the gasket and baffle from the fuel tank cap
is often a problem when the fuel tank cap is removed from the
filler neck. Additionally, a separated or misaligned gasket may not
properly seal between the fuel tank cap and the filler neck,
resulting in liquid gas venting from the fuel tank.
[0007] Therefore, what is needed is a fuel tank cap assembly that
better retains the flexible gasket component thereof while
minimizing the number of components and assembly steps.
BRIEF SUMMARY OF THE INVENTION
[0008] The present invention provides an improved vented fuel tank
cap assembly. The vented fuel tank cap assembly includes a cap
member having a disk-shaped cover portion and a cylindrical skirt
portion extending therefrom. The cylindrical skirt portion includes
internal threads for engagement to matching external threads
located on the fuel tank neck portion. The internal and external
threads cooperate to define a vent path therebetween. The cap
member includes a tubular central post depending downward from the
interior of the cover portion. Advantageously, the tubular central
post is integral with the cap member. A filter element having a
central hole for receiving the central post is located adjacent the
interior of the cover portion. The filter element is held in
position by a gasket having an annular rim surrounding a dome
portion, the dome portion having a central hole disposed on the
central post and compressing the filter against the interior cover
portion. The annular rib around an outside diameter of the central
post retains the gasket to the cap member slightly deforming the
dome portion and sealing the annular rim against the interior
surface of the cap member. Radial grooves are provided on the upper
surface of the annular rim, i.e., the surface in contact with the
interior surface of the cover portion.
[0009] The components of the vented fuel tank cap assembly are
easily assembled. First, the filter element is slid onto the
central post of the cap member, so that one side of the filter
element is against the interior of the cover portion and the
central post extends through the hole in the filter element.
Second, the gasket is slid onto the central post, the dome portion
extending away from the cap member. The dome portion is pressed
toward the cap member cover portion, compressing and capturing the
filter element, until the dome portion hole passes over the annular
rib or other protuberance protruding from the central post. In this
position, the annular rib retains the gasket and the filter element
to the cover member and the annular rim is held in contact with the
interior surface of the cover portion.
[0010] The assembled fuel tank cap provides a vent path for
exchanging gases between the fuel tank and the surrounding
atmosphere. The vent path is provided from the downward-depending
end of the tubular central post, through the central post wall,
through the porous filter element, through the grooves provided in
the upper surface of the annular rim, and outwardly through the
nonsealing threads of the cylindrical skirt member and neck filler
portion to the surrounding atmosphere.
[0011] Advantageously, the vented fuel tank cap assembly firmly
retains the gasket and filter element to the cap member. Also, the
annular rim is held in position by the central post rib so that a
seal is formed between the gasket and the filler neck end portion
when the fuel tank cap is attached to the fuel tank. Additionally,
the filter element and gasket are easily assembled with the cap
member using a single step of positioning the filter element and
gasket over the central post and rib. Thus, no additional
manufacturing steps are required to complete the assembly or retain
the components in position.
[0012] In one form thereof, the vented fuel tank cap assembly
includes a cap member having a circular cap portion and a
downwardly depending skirt portion, the skirt portion including an
engagement portion for removably attaching the cap assembly to a
filler neck portion of a fuel tank, the cap portion including a
cylindrical post depending from an interior of the cap portion, the
post having at least one rib extending exteriorly around at least a
portion thereof. The cap assembly further includes a gasket having
an annular rim surrounding a dome portion and an opening in the
dome portion, wherein the opening fits around the post and the rib
retains the gasket to the cap member.
[0013] In another form thereof, the vented cap assembly includes a
cap member having a circular cap portion and a downwardly depending
skirt portion--the skirt portion including an engagement portion
for removably attaching the cap assembly to a filler neck portion
of a fuel tank, the cap portion including a post depending from an
interior of the cap portion; and a circular gasket having an
opening defined therethrough, an upper surface engageable with the
interior surface of the cap portion, and a lower surface opposite
the upper surface, the opening disposed around the central post;
the post defining a vent path for communication of gases adjacent
the lower surface with gases adjacent the upper surface.
[0014] In yet another form thereof, the vented fuel tank cap
assembly for a filler neck end portion of a fuel tank includes a
cap member having a circular cap portion and a downwardly depending
skirt portion, the skirt portion including nonsealing threads for
removably attaching the cap assembly to the filler neck end
portion, the cap portion including a tubular post depending from an
interior surface of the cap portion, an interior surface of the
tubular post defining a first deflection surface and a first vent
path therethrough; and a gasket having an annular rim surrounding a
dome portion and an opening defined in the dome portion, the
opening engaged around the tubular post, the gasket and an exterior
surface of the tubular post defining a second deflection surface;
the annular rim contacting the interior of the cap portion and
forming at least one second vent path therebetween.
[0015] In another form thereof, in combination, a fuel tank having
a fuel tank neck portion, and a fuel tank cap having: a cap member
including a circular cap portion and a downwardly depending skirt
portion, the skirt portion including an engagement portion for
removably attaching the cap to the filler neck portion, the cap
portion including a tubular post depending from an interior of the
cap portion, the tubular post having a rib extending exteriorly
around at least a portion thereof; and a gasket having an annular
rim surrounding a dome portion and an opening in the dome portion,
wherein the opening fits around the tubular post and the rib
retains the gasket to the cap member.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0016] The above-mentioned and other features and advantages of the
invention, and the manner of obtaining them, will become more
apparent and the invention itself will be better understood by
reference to the following description of embodiments of the
invention taken in conjunction with the accompanying drawings,
wherein:
[0017] FIG. 1 is a side perspective view of a lawnmower having a
small internal combustion engine, a fuel tank, and a fuel tank cap
assembly in accordance with the present invention;
[0018] FIG. 2 is a side perspective view of a portion of the engine
of the lawnmower of FIG. 1, showing the fuel tank cap assembly;
[0019] FIG. 3 is a sectional view taken along line 3-3 of FIG.
1;
[0020] FIG. 4 is an exploded perspective view from above of the
fuel tank cap assembly of FIG. 1; and
[0021] FIG. 5 is an exploded perspective view from below of the
fuel tank cap assembly of FIG. 1.
[0022] Corresponding reference characters indicate corresponding
parts throughout the several views. The exemplification set out
herein illustrates an exemplary embodiment of the invention, and
such exemplification is not to be construed as limiting the scope
of the invention in any manner.
DETAILED DESCRIPTION
[0023] Referring to FIGS. 1 and 2, lawnmower 10 having a small
internal combustion engine includes fuel tank 14. Fuel tank 14 has
an open filler neck end portion 16 (FIG. 2) providing an opening
therein for filling fuel tank 14 with fuel. Vented fuel tank cap
assembly 12 is attached to filler neck end portion 16 to prevent
liquid fuel from escaping fuel tank 14. Lawnmower 10 is an
exemplary implement. Vented fuel tank cap assembly 12 may also be
attached to a fuel tank filler neck end portion on other types of
small implements having gasoline powered engines, for example
garden tillers, snow blowers, sport vehicles, and electric
generators. Alternatively, vented fuel tank cap assembly 12 may be
attached to other tanks or reservoirs requiring venting of
vapors.
[0024] Referring now to FIGS. 3-5, vented fuel tank cap assembly 12
generally includes cap member 31, filter element 18, and gasket 20.
Gasket 20 is attached to cap member 31 and captures filter element
18 between cap member 31 and gasket 20.
[0025] Referring to FIG. 3, cap member 31 includes disk-shaped
cover portion 32 and downwardly depending cylindrical skirt portion
33. The interior of skirt portion 33 defines threads 39 that engage
filler neck threads 17 defined on the outside of filler neck end
portion 16. The fit and engagement of cap member threads 39 with
filler neck threads 17 retains cap member 31 to filler neck 16
while defining a vent passage therebetween for escape of fuel
vapors.
[0026] Depending downwardly from interior surface 34 of cover
portion 32 is central post 35. Central post 35 is shown as
generally tubular, having a cylindrically-shaped exterior surface
36 and a cylindrically-shaped interior surface 37. Central post 35
is integrally formed with cap member 31, which may be molded of
plastic or other similar material. Post 35 may be another shape,
such as a square or triangular cross-section, for example.
Additionally, post 35 may depend from the center of cover portion
32 or from another part of cover portion 32.
[0027] Referring to FIGS. 4 and 5, gasket 20 includes an annular
generally flattened sealing rim 21 surrounding a downwardly
depending dome-shaped cavity 24. The central bottom portion of dome
24 defines hole 25 therethrough. Gasket 20 has an upper surface 22
and an opposite lower surface 23. The upper surface 22 of annular
rim 21 defines four grooves 28 circumferentially spaced around
annular rim 21. Notches 29 are defined on the outside edge of
annular rim 21 adjacent each groove 28. Gasket 24 is advantageously
made of rubber or other material that is impervious to and
non-reactive with liquid fuel and which is flexible.
[0028] Filter element 18 is generally rectangular shaped and
defines a hole centrally therethrough. Filter element 18 allows
transmission of fuel vapor and atmospheric gases but is generally
impervious to liquid fuel. Filter element 18 may be constructed of
reticulated flexible polyurethane with open pores of approximately
50 per inch, for example, or other similar porous material which
will trap liquid fuel, yet allows vapors to pass therethrough.
Filter element 18 is positioned between cover portion 32 and gasket
20 in dome-shaped cavity 24.
[0029] Fuel tank cap 10 operates to allow fuel vapor to vent from
fuel tank 14 and/or to allow atmospheric gases to enter fuel tank
14. As shown in FIGS. 3 and 5, vent path slot 41 is defined
vertically along a portion of the length of central post 35.
Specifically, slot 41 extends through the tubular wall of central
post 35 from the downwardly depending end, toward cover portion 32,
ending at slot end 42. Advantageously, slot end 42 is located above
the level of dome 24 and adjacent to filter element 18.
Additionally, grooves 28 between upper surface 22 of rim 21 and
interior surface 34 of cap portion 31 and notches 29 define a vent
path therethrough. Thus, fuel vapor escapes fuel tank 14 by passing
from the interior of central post 35, through vent path 41 at slot
end 42, through porous filter element 18, and into the space
defined between gasket dome 24 and cover portion 32. The vent path
for escaping fuel vapors continues through grooves 28 and notches
29 between annular rim 21 and cover portion interior surface 34,
and between nonsealing threads 39 and filler neck threads 17.
[0030] Referring to FIG. 3, the vented fuel cap assembly 12 is
assembled as follows. Hole 19 of filter element 18 slides onto
central post 35 until a surface of the filter is compressed against
interior surface 34 of cover portion 32. Gasket 20 then slides onto
central post 35 until hole 25 passes over and is engaged by annular
rib 43 defined around an external portion of central post 35,
thereby retaining gasket 20 to cap member 31. In this engaged
position, gasket 20 is firmly retained to cap member 31, and dome
24 is slightly deformed toward cap member 31 and annular rim 21 is
sealingly compressed against interior surface 34 of cover portion
32. Rib 43 may be a single annular protuberance defined around part
of or the entire diameter of central post 35, or may alternatively
be a segmented series of protuberances, a single protuberance, or
other arrangement of protuberances.
[0031] In this arrangement, vented cap assembly 12 may be
threadably engaged to filter neck end portion 16 and operates to
prevent liquid fuel from escaping fuel tank 14 while providing
venting of fuel vapors to the atmosphere. As cap member 31 is
screwed onto filler neck end portion 16, annular rim 21 of gasket
20 is captured between a top end of filler neck end portion 16 and
interior surface 34 of cover portion 32, thus forming a seal
between lower surface 23 of rim 21 and filler neck portion 16.
[0032] In this installed position, vented cap assembly 12 forms two
deflection surfaces that resist venting of liquid fuel from fuel
tank 14. The first is formed by exterior surface 36 of central post
35 and by gasket 24 which is sealably pressed against the upper end
of filler neck end portion 16. The second deflection surface is
defined by the interior surface 37 of central post 36. The
deflection surfaces reduce splashing of liquid fuel toward the vent
path, thus ensuring only fuel vapors are vented.
[0033] The escape of liquid fuel from fuel tank 14 is further
prevented by the difficulty of liquid fuel reaching vent path 41
along slot end 42 and the resistance of filter element 18 to the
flow of liquid fuel. Liquid fuel that reaches filter element 18
will be drained by gravity back through vent path 41 and back into
fuel tank 14.
[0034] While the invention has been illustrated and described in
detail in the drawings and foregoing description, the same is to be
considered as illustrative and not restrictive in character. It
should be understood that only the preferred embodiments have been
shown and described and that all changes and modifications that
come within the spirit of the invention are desired to be
protected.
* * * * *