Note: Descriptions are shown in the official language in which they were submitted.
0~
Thi~ is a continuation-in-part of my copending United States Patent
Application Serial No. 706,051 filed July 16, 1976, titled "0-Ring", and
assigned to the same assignee as the instant application.
This invention relates to sealing rings for sealing annular spaces
between surfaces. The type of sealing ring to which thig invention relates
is commonly referred to as an "O-ring". More specifically, this invention
relates to an improved type of 0-ring having a C-shaped radial cross section
in a plane extending through the axis of the ring.
0-rings ha~ing non-circular radial cross sections in planes extend-
ing through their axes are known in the art. 0-rings of this type are des-
cribed in, ~or example3 the following United States patents:
Patent Number Issue Date Inventor
1~697,814 January 1, 1929 Forbes
2,271,777 February 3, 1942 Nathan
2,547,185 April 3, 1951 Von Bolhar
2j729,478 January 3, 1956 Chambers~ Jr. et al
2,733,052 January 31, 1956 Luther
2,746,778 ~ay 22, 1956 Hurlburt et al
2,882,073 April 14, 1959 James
2,906,552 September 29, 1959 White
3,015,510 January 2, 1362 Bates
3,085,515 April 16, 1963 Workman
3,052,476 September 4, 1962 Workman
3,127~049 March 31, 1964 Welty et al
3,347,556 October 17, 1967 Fleckengtein et al
3,366,392 January 30, 1968 Kennel
3,418,001 December 24, 1968 Rentschler et al
3,490,232 January 20, 1970 Baldwin
3,498,623 March 3, 1970 Rowe
3,572,539 March 30, 1971 Wunderlich
3,591,207 Ju~ 6, 1971 Fisher ~ -
3,746,209 July 17, 1973 Urban et al
3,854,761 December 17, 1974 David
3,918,605 November ll, 1975 Butler
The following foreign patent specifications algo digclose guch 0-
rings:
British Patent 926,789
German Offenlegungsschri~t 2,262,968
Netherlands Octrooiaanvrage 6,710,603
When such 0-rings are made of resilient materials, the 0-rings col~
lapse to fill, or partly to ~ill, annular spaces between parts 90 that the
-- 1 --
. ~ ,........................ .
. . .
parts are sealed to one another.
It is a primary~ obj:ect of the present invention to
provide improyed resilient rings for sealing annular spaces ~ '
between parts, and particularl~ to seal a gas cap to a filler :
neck.
According to one aspect of the present invention there
is provided a fuel fi.ller neck cap with an 0-ring seal, the cap ' ~ .
having a shank insertable into a filler neck and a peripherally
and radially outwardly extending sealing flange at the outer end ':~ -
of the shank, said 0-ring compri.sing an annular web portion ' ''
disposed adjacent sai.d shank, an axi.ally inner lip for engaging
said filler neck. and an axi.ally outer lip, said lips extending ' :~
.:
peripherally about and radially outwardly from said web portion.
According to another aspect of the present inYention, ; '
: : - .. :
there i.s provided in com~ination, a cap for a fuel tank filler
neck, the cap haying a radially outwardly and peripherally : .
extending, axi.ally i.nwardly facing sealing flange surface and a
generally cylindri.cal portion extending axially inwardly from .
said sealing surface for proYiding a first radially inner surface,
the neck hayi.ng an axi~lly outwardly facing annular sealing lip : ' '
and bei:ng generally cy~li.ndxical for provi.ding a second radially
outer surface, the firsiL surface being axi.ally projected into
the second surface when th:e cap is placed in clos.ing engagement
on the neck 'definl.ng between thé'fixst and second surfaces an '~
annular space, and a res.i:lient annular ring for sealin~ the '~
annular space mounted on the first surface adjacent the sealing ~
flange surface of the cap, the' annular space haYin~ a radial .: ..
width less than the radial width 'of the ring, the ring including .': .~ '
peripherally and radially outwardly extending axi.ally inner
and axially outer lips and an axially extending web joining the
, .' ' :'' ' ''. '
' .
--2--
1 r~
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.
Z~9
inner and outer lips, the web being disposed adjacent the first
surface, the inner and outer li.ps each. including axially inner ~:
and outer surfaces ~nd the web i:ncluding a radially inner surface
adjacent the first surface and a radially outer surface, the
inner lip axially outer surface, the outer lip axially inner : ;
surface and the web radially outer surface defining a radially
outwardly opening grOQve~ th.e ring being formed for resilient
axially outw.ard wiping moYement of the i.nner lip upon axial
moYement of the first surface into the second.
As the 0-ring is projected axially into the annular - .:
space, the axially i.nner surface of the axially inner lip
contacts the second surface, causing an initial, or first, seal ; - .
to be made. As the first surface and the 0-ring are axial].y
inserted further into the second surface, the axially inner ;
surface of the i.nner li.p begins to slide or wipe along the second
surface. This wipi.ng action causes a bending moment to develop ~ .
in the inner lip and the axially inne-~ portion of the web, with ~ .
the inner lip moving axially out~ardly and radially inwardly
from its unstressed pos-iti.on. :
The bending moment thus established creates tensile .
stress radially along the inner lip axially inner surface and
compressive stress radially along the inner lip axially outer
surface. The axi.ally out~ard wiping mo~ement of the i.nner lip
resiliently urges the 0-ri.ng in a twisting or rolling motion
such that a second seal is established between the first surface
and the radi.ally inner surface of the 0-ring. The force of
this second seal is in equilibrium wi.th. the force of the first
seal.
-2a-
,
' ' . ' ' '
~;~o~jg
As insertion of the first surface into the second continues, the
applied forces to the axially inner lip create a second bending moment near
the radially and axially inner extent of the 0-ring, the rolling action caus-
ing the web radially inwardly facing surface to be urged radiall~ outwardly
at its axially inner extent. This second bending moment is caused by the
tensile stress along the axially inner surface of the axially inner lip equal-
i~ing with tensile stress along the radial~y inwardly facing surface of the
web, and compressive stress along the axially outer surface of the axially
inner lip equalizing with compressive stress established on the radiall~ out-
wardly facing surface of the web.
In one illustrative embodiment, the axially inner surface of the
outer lip contacts the second surface. Tensile stress along the axially ~ -
inner surface of the outer lip, and compressive stress along the axially ~-
outer surface of the outer lip establish a third bending moment urging the
outer lip axially outwardl~. The last-mentioned tensile stress reduces the
compressi~e stress along the web radially outer surface, which reduction pulls
the web radially outer surface radially outwardly at its junction with the
axially outer lip. When the 0-ring has reached full installation depth, the
axially inner surface of the axially outer lip creates a direct compressive
seal between the lip of the filler neck and an axially inwardly facing sur-
face of the cap.
In two illustrative embodiments of the instant invention, the axially
outer surface of the inner lip includes a first annular compression ring.
The first compression ring includes an axially outwardly facing top surface
and an axially outwardly and radially inwardly extending inclined surface.
, ,, :
The inclined surface in the illustrated embodiments is inclined at approximate-
ly 45 to the top surface of the first compression ring. When the first sur-
face and 0-ring are inserted fully into the second surface, the first com-
pression ring contacts a wall of the groo~e. A fourth seal is thereby created.
Further, in two illustrative embodiments, a second, annular compres-
- 3 -
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: -: .: - . . , , ., : .
.
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sion ring is defined on the axially inwardly facing surface of the outer lip.
The second compression ring includes an axially inwardly facing bottom sur
face and a radially and axially inwardly facing inclined surface. The inclined
surface makes an approximately 45 angle with the bottom surface of the second
compression ring.
In two illustrative embodiments, the annular groove is defined in
part by the radially outer surface of a straight web. The web extends be-
tween and connects the radially inner extents of the axially inner and outer
lips. The web also includes a straight, radially inner surface which li8s
against the ~irst surface. Establishment of the second bending moment causes
the web to be deflected radially outwardly at its axially inner extent and
to be urged radially inwardly at its axially outer extent against the first
surface.
In a third illustrative embodiment, the web has curved radially ~
inner and outer walls that are formed continuousl~ with the walls of the ; -
axially inner and outer lips.
Additional objects of the present invention will become apparent ~
to those skilled in the art to which the invention pertains by referring to -~ -
the following descriptions of preferred embodiments and the accompanying
drawings which illustrate the invention.
In the drawin~s:~
Figure 1 is a cross sectional view of a vehicle fuel cap equipped
with a sealing ring according to one embodiment of the instant invention,
engaging a vehicle fuel filler neck;
Figure 2 is a fragmentary radial cross sectional view of the seal-
ing ring of Figure 1, taken through the plane of the axis of the sealing ring,
Figure 3 shows the vehicle fuel cap of Figure 1, with the sealing
ring of Figures 1-2, misaligned in a fuel tank filler neck to show the tend-
ency of the sealing ring to return the fuel cap to a proper orientation;
Figure 4 is a cross sectional view of a vehicle fuel cap equipped
.
1~2(~9 : :
.. ,~ .
with a sealing ring according to one embodiment of the instant invention,
engaging a vehicle fuel filler neck;
Figure 5 is a fragmentary radial cross sectional view of the seal- ;
ing ring of Figure 4, taken through the plane of the axis of the sealing ring; ~
, . . .
Figure 6 sho~æ the vehicle fuel cap of Figure 4, with the sealing
ring of Figures 4-5, misaligned in a fuel tank filler neck to show the tend-
ency of the sealing ring to return the fuel cap to a proper orientation;
Figure 7 is a cross sectional view o~ a vehicle fuel cap equipped ;-
with a sealing ring according to one embodiment of the instant invention,
engaging a vehicle fuel filler neck;
Figure 8 is a fragmentary radial cross sectional view of the seal-
ing ring of Figure 7, taken through the plane of the axis of the sealing ring; -
Figure 9 shows the vehicle fuel cap of Figure 7, with the sealing
ring of Figures 7-8 misaligned in a fuel tank filler neck to show the tend-
ency of the sealing ring to return the fuel cap to a proper orientation;
Figure 10 is a cross sectional view of a vehicle fuel cap e~uipped ;
with a sealing ring according to one embodiment of the instant invention, en-
gaging a vehicle fuel filler neck; ~
Figure 11 is a fragmentary radial cross sectional view of the seal- ~;
ing ring of Figure 10, taken through the plane of the axis of the sealing
ring; and,
Figure 12 shows the vehicle fuel cap of Figure 10, with the sealing
ring of Figures 10-11 misaligned in a fuel tank filler neck to show the tend- ~-
enc~ of the sealing ring to return the fuel cap to a proper orientation. ;
Referring to Figure 1, the annular sealing ring 10 seals an annular
space 12 between a first radially inner surface 14, e.g., a radially outer
surface of a combination closure member and pressure-vacuum vent valve housing
1~ of a fuel filler neck cap 18, and a second, radially outer surface 20,
e.g., the radially inner surface of a fuel filler neck 22.
Referring to Figure 2, ring 10 has an annular, radially outwardly
- 5 -
, ~ ao~zo~
;::
opening groove 24. Ring 10 further includes an axially inner lip 26, an
axially outer lip 28 and a connecting radiall~ inner web portion 30. Inner
lip 26 includes an axially inner surface 32 and an axially outer surface 34.
Web 30 includes a radially inwardly facing surface 36 and a radially outwardly
facing surface 38. Outer lip 28 includes an axially inner surface 40 and an
axially outer surface 42.
Annular, radially outwardly opening groove 24 is defined by sur-
faces 34, 38, and 40. The web radially inner surface 36 includes an axially
outer extent, or edge, 44 and an axially inner extent, or edge 46.
Referring again to Figure 1, ring 10 is disposed about the radially
outer surface 14 of valve housing l6 of fuel cap 18. As cap 18 is projected
axially inwardly into fuel filler neck 22, axially inner surface 32 contacts
the lip 48 at the axially outer end of filler neck 22. This contact estab-
lishes a first seal between surfaces 14~ 20 Continued insertion causes a
sliding or wiping movement between surfaces 20, 32
Contact with lip 48 causes a first bending moment to develop which
urges the sealing ring inner lip 26 axially outwardly and radially inwardly. `
The first bending moment creates tensile stress along surface 32 and com-
pressive stress along surface 34. A force i9 established between surfaces 14
and 44. This force is in equilibrium with a force established between sur-
faces 20, 32.
As ~xial insertion continues, a second bending moment develops along
edge 46, with a resulting twisting or rolling of ring 10 which causes the
axially inner edge 46 of inner surface 36 to be urged radially outwardly. ~ `~
This second bending moment is accompanied by tensile stre3s along surface 32
which equalizes the tensile stress along surface 36. Compressive stress de-
velops along surface 34 which equalizes the compressive stress along surface
38. The axiall~ outer edge 44 of surface 36 is urged against surface 14 of
valve housing 16. Resilient bending at edge 46 allows the sealing forces
exerted by the axially inner surface 32 of inner lip 26 on the filler neck
-- 6 --
" '~
,
, ' . ' . : ' , .
0~:i9
lip 48 and the force exerted by edge 44 on surface 14 to reach equilibrium.
At equilibrium, a radial seal is established in annular space 12.
Axiall~ inner surface 40 of outer lip 28 also contacts lip 48 of -~
filler neck 22 when cap 18 is projected axially into filler neck 22. This
establishes a bending moment on lip 28. Tensile stress is established on
surface 40 and compressive stress on surface 42. The tensile stress on sur-
face 40 reduces the compressive stress on surface 38. The co~pressive stress
on surface 42 reduces the tensile stress along surface 36. This reinforces
the twisting or rolling of the web radially outwardly at its axially inner
extent and increases the force exerted by the axially outer edge 44 of sur-
face 36 against surface 14. Equilibrium is maintained between the force ex-
erted upon surface 20 of the neck 22 by surface 40 and a component of the
force exerted upon surface 14 of valve housing 16 by edge 44. This equilib-
rium provides a direct, compressive, static, axial seal between surfaces 14,
20.
The annular ring 10 is capable of withstanding axial and radial ;
... .
misaligning movement under static or dynamic loading to prevent the seal -
created thereby in the annular space 12 from breaking. Relative movement of
surfaces 14 and 20 selectively decreases and increases the radial and/or axial
20 compressive forces exerted between such surfaces. Such selective variation
tends to realign the cap in the filler neck. The tendency of the sealing ring
to bring the fuel cap back into proper alignment of the fuel filler neck can
best be understood by referring to Figure 3. In Figure 3, a misaligned con-
dition of the cap on the neck is illustrated. Such misalignment can occur
during a collision, for example. The increase in axial and/or radial com-
pression of the right-hand portion of the ring 10 in Figure 3 is accompanied
by a corresponding decrease in the compression of ring 10 on the left-hand
side. Since ring 10 is structurally symmetrical about its axis, the added
compression on the right-hand side e~erts a restoring force between the axially
inwardly facing surface 49 of cap 18 surrounding housing 16, and the lip 48
- 7 -
, ,: , - . - i. . . : ,................................... .- :
::, . . ,. .. . ... :.
of filler neck 22. This restoring force tends to equalize the force exerted
upon surfaces 48, 49 by ring 10 about the entire periphery of the cap 18 and
neck 22,
Ring 10 can be constructed of any suitable resilient material which
is sufficiently chemically resistant to avoid reaction with the environments
which it seals. Illustratively, a ring 10 for sealing an automobile fuel
filler neck cap to enclose the gasoline vapor environment within the fuel
filler neck can be constructed of urethane rubber. One such sealing ring 10
was made with an outside diameter of 2 inches and an inside diameter of 1.58
inches. The thickness of web 30 was .06 inch. The axial thickness of the
ring 10 (axial length of wall 36) was .250 inch. The axial thickness of each
of lips 26, 28 where it joins web 30 was approximately .08 inch.
A second embodiment of the O-ring is illustrated in Figures 4-6.
In this embodiment, those elements numbered similarly or identically to ele- ; ~-
ments in the embodiment of Figures 1-3 perform the same or similar functions.
Referring now to Figures 4-6~ the axially outer surface 34 of inner
lip 26 is provided with a compression ring or bead 50. Compression ring 50
includes an axially outwardly facing top surface 52 and an axiall~ outwardly
and radially inwardly extending surface 54 which faces the interior of groove
24. Surface 54 is inclined at approximately 45 to surface 52. A radially
outwardly facing surface 56 extends between the periphery of surface 52 and
axially inner surface 32 of inner lip 26. Surface 34 of inner lip 26 inclines
at an angle of 10 with respect to horizontal.
An upper compression ring 60 is provided on the axially inwardly
facing surface 40 of lip 28. Ring 60 includes an axially inwardly facing
bottom surface 62 and a radially and axially inwardly facing surface 64.
Surface 64 makes an approximately 45 angle with surface 62 in the illustrated
embodiment. A radially outwardly facing surface 66 extends between the peri-
phery of surface 62 and the axially outer surface 42 of outer lip 28. Surface
40 inclines at an angle of 10 with respect to horizontal.
-- 8 --
. .
~0~21)~9
'
The O-ring of Figures 4-6 is designed to behave somewhat differently :
under compression than the ring of Figures 1-3. In the embodiment of Figures ~;
4-6, the axially inner lip undergoes a "double-bending" to seal the annular ~
space 12 radially. Under normal operating conditions, best illustrated in ~ -
Figure 4, surface 62 of compression ring 60 does not come into contact with
the lip 48 of filler neck 22. Only when misalignment of the cap 18 on neck : .
22 occurg (Figure 6) is compression ring 60 pinched between lip 48 and sur-
face 49 to urge cap 18 into~its normal orientation (Figure 4).
Ordinarily, when the axially inner surface 32 of inner lip 26 first
contacts lip 48, a bending moment is established in lip 26. Lip 26 is de-
flected axially outwardly and radially inwardly, as in the preceding embodi- .
ments, as movement of surface 14 axially into surface 20 continu0s. -~
Axially outward deflection of lip 26 continues until surface 52 of
compression ring 50 lies against axially inner surface 40 of outer lip 28 `.
adjacent surface 64 of compression ring 60. At this time, surface 56 of ring .
50 lies against surface 64 of ring 60. Further projection of surface 14 ;~:
axially into surface 20 results in compression of ring 50 against outer lip
28 and establishment of a recurve-, reverse- or double-bending moment in the
region of arrow 70 of ring 10 in Figures 4-6. Such double-bending near the .~ ~ -
radially outer extent of inner lip 26 results as lip 26 is compressed about
the contour of ~iller neck lip 48. The compressive forces exerted upon the : :
material of lip 26 in the region of ring 50 are in equilibrium with compress-
ive forces on the material in lip 28 in the region adjacent and radially in-
wardly from compression ring 60. Both of these regions are pinched between
lip 48 of filler neck 22 and surface 49 of cap 18.
The following are ill~strative dimensions for an O-ring seal 10 of :
the type illustrated in Figures 4-6: surface 36 axial length, .250 inch; sur- ` ~:
face 38 axial length, (approximately) .09 inch; web 30 radial thickness, .120 `
inch; lips 26, 28 axial dimension from surface 38, .15 inch; axial distance
from surface 52 to surface 62, .04 inch; minimum axial distance from surface -.
'" ~'
_ 9 _ . .
,
': , ' ,. ~ : ' ' '
10~20 rj9
.. .- .
.. .
32 to surface 42, .16 inch; axial leng~h of surface 56 and surface 66, .06
inch; radial length of surface 52 or surface 62, .02 inch; outside diameter
of ring 10, 2.125 inches; and, inside diameter of ring 10, 1.58 inches.
Referring to Figure 8, the ring 10 of the third embodiment includes ..
an annular, radially outwardly opening groove 24, an axially inner lip 26,
and an axially outer lip 28 connected by a web portion 30. The radially in-
wardly facing surface 36 and radially outwardly facing surface 38 of web por-
: .: i. . .
tion 30 are both curved to form continuous contours between the surfaces of
lips 26, 28. That is, surface 38 smoothl~ and continuously joins the axially ~::
inner surface 40 of lip 28 and the axially outer surface 34 of lip 26. Web
~ - .
surface 36 smoothly and continuously joins axially inner surface 32 of lip 26 ~.
with axially outer surface 42 of lip 28. Thus, in the illustrative embodi-
ment of Figures 7-9, there are no well defined edges or breaks between sur- :
faces 34, 38, 40 or between surfaces 32, 36, 42.
In this embodiment, as in the embodiment of Figures 4-6, axially ;~.
outer surface 34 of lip 26 is provided with a compression ring 50. Compres- :
sion ring 50 includes axiaIly outwardly facing surface 52 and axially out-
wardly and radially inwardly facing surface 54. Again, surface 54 is illus- .
tratively inclined at approximately 45 to surface 52. Peripherally and
axially extending surface 56 extends between the peripherally outer extent of .
surface 52 and the axial~y outward curvature of surface 32. `:
Compression ring 60 is provided on the axially inwardly facing sur-
face 40 of lip 28. Ring 60 includes axially inwardly facing surface 62 and
radially and axially inwardly facing surface 64. Surface 64 illustratively
makes an approximately 45 angle with surface 62. Peripherally and axially `.
extending surface 66 extends between the peripherally outer extent of surface
62 and the ~xially inward our~ature of surface 42.
The 0-ring of Figures 7-9 is designed to behave in generally the
same manner as the ring of Figures 4-6. The axially inner lip undergoes . .
double-bending to seal the annular space 12 radially. Under normal operating ~`
-- 10 --
ZOS9
conditions, best illustrated in Figure 7, surface 62 of compression ring 60
does not come into contact with the lip 48 of filler neck 22. Only when mis-
alignment of the cap 18 on neck 22 occurs (Figure 9) is compression ring 60
pinched between lip 48 and surface 49 to urge cap 18 into its normal orienta-
tion (Figure 7).
Ordinarily, when the axially inner surface 32 of inner lip 26 first
contacts lip 48, a bending moment is established in lip 26. Lip 26 is de-
flected axiall~ outwardly and radially inwardly, as in the preceding embodi- ;
ments, as movement of surface 14 axially into surface 20 continues.
Axially outward deflection of lip 26 continues until surface 52 of
compression ring 50 lies against axially inner surface 40 of outer lip 28
adjacent surface 64 of compression ring 60. ~t this time, surface 56 of ring
50 lies against surface 64 of ring 60. Further projection of surface 14
axially into surface 20 results in compression of ring 50 against outer lip .-
28 and egtablishment of the double-bending moment in the region of arrow 70
of ring 10 in Figures 7-9. Such double-bending near the radiall~ outer ex-
tent of inner lip 26 results as lip 26 is compressed about the contour of ~
filler neck lip 48. The compressive forces exerted upon the material of lip .
26 in the region of ring 50 are in equilibrium with compressive forces on the
material in lip 28 in the region adjacent and radially inwardly from compres-
sion ring 60. Both of these regions are pinched between lip 48 of filler
neck 22 and surface 49 of cap 18.
The following are illustrative dimensions for an C-ring seal 10 of
the type illustrated in Figures 7-9: max i axial dimension of ring 10, :
.225 inch; maximum axial dimension of groove 24, .185 inch; web 30 thickness
between walls 36, 38, .1 inch (approximately uniformj; maximum radial dimen- .: .
sion of ring 10, .210 inch; axial distance from surface 34 to surface 52, and ~ :
from surface 42 to surface 62, .07 inch; radial length of surface 52 and sur- .
face 62, .02 inch; outside diameker of ring 10, 2 inches; and, inside diameter
of ring 10, 1.58 inches.
- 11 -
:. .' . . .. . : '
.; ' ' ', '' .'',.' ',' ', '., , ,, :
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ZOS9
The sizes, shapes and materials of the illustrated 0-rings are ~ -
helpful to achieve the described sealing characteristics. The lips of the '
described 0-rings are designed to maintain uniform fiber stress in both ten- ~'sion and compression. It is currently considered desirable that the lips ~ 'taper from the web radially outwardly. This accounts for the radius of sur- ' '
face 32 This radius helps facilitate wiping action upon installation. This
radius also helps insure the integrity of the seal on misalignment.
The web is designed to bend in the groove 24 region between inner
and outer lips 26, 28. This helps to localize the sealing force exerted "~-
against surface 14 of housing 16, for example, in the embodiments of Figures
1-6, in the region of edge 44. This also helps to keep the region of lower -'
lip 26 adjacent the radially outer extent of surface 32 out of contact with '-'~surface 20 of the filler neck, thereby preventing this region from "digging" ~ '
into the side of the filler neck to impair the removal of the cap.
In the embodiments of Figures 4-9, the compression rings on the
inner lip 26 solidly contact the surfaces of groove 24 to promote the dynamic
seal of the annular space 12.
Groove 24 should be axiall~ wide enough to allow lip 26 to flex
axially outwardly and radially inwardly without interference from the outer '
lip 28. This allows the surfaces of compression ring 50 to move into contact
with the surfaces of groove 24. In the embodiments of Figures 4-9, this means
, ~,
that the web axial length desirably is greater than the maximum radial dimen-
sion of the web and lip 26 combined.
In practice, it has been found that to accomplish this last objec-
tive, it is desirable'to make the lip 26 radial dimension at least two-thirds
of the web 30 axial dimension.
A fourth embodiment of the 0-ring is illustrated in Figures 10-12.
In this embodiment, those elements numbered similarly or identically to ele-
ments in the embodiments of Figures 1-9 perform the same or similar functions.
Referring now to Figures 10-12, the axially outer surface 34 of inner
. .
- 12 _
,: ,
~ z~9 ::
lip 26 is provided with a compression ring or bead 50. Compression ring 50
includes an axially outwardly facing top surface 52 and an axially outwardly
and radially inwardly extending surface 54 which faces the interior of groove
24. Surface 54 is inclined at approximately 45 to surface 52. A radially
outwardly facing surface 56 extends between the periphery of surface 52 and
axially inner surface 32 of inner lip 26. Surface 34 of inner lip 26 inclines
at an angle of 10 with respect to horizontal.
An upper compression ring 60 is provided on the axially inwardly
facing surface 40 o~ lip 28. Ring 60 includes an axially inwardly facing
bottom surface 62 and a radially and axially inwardly facing surface 64. ~;~
Surface 64 makes an approximately 45 angle with surface 62 in the illustrated
embodiment. A radially outwardly facing surface 66 extends between the peri-
phery of surface 62 and the axially outer surface 42 of outer lip 28. Surface ~ ; -
40 inclines at an angle of 10 with respect to hori~ontal.
The O-ring of Figures 10-12 is designed to behave somewhat in the
same manner under compression as the ring of Figures 1-3. In the embodiment
of Figures 10 12, the axially inner lip bends in the same manner as in the
embodiment of Figures 1~3 to seal the annular space 12 radially Gompression
rings 50, 60 of this embodiment distinguish it from the embodiment of Figures
1-3.
Under normal operating conditions, best illustrated in Figure 10,
surface 62 of compression ring 60 comes into contact with the lip 48 of
filler neck 22. Ordinarily, when the axially inner surface 32 of inner lip
26 first contacts lip 48, a bending moment is established in lip 26. Lip
26 is deflected axially outwardly and radiall~ inwardly, as in the preceding
embodiments, as movement of surface 14 axially into surface 20 continues.
Axially outward deflection of lip 26 continues until surface 52 of
compression ring 50 lies against axially inner surface 40 of outer lip 28
adjacent surface 38 of web 30. At full projection of closure 16 into neck
229 compression ring 60 is compressed between surfaces 48, 49. Contact be-
- 13 -
.
~09~0~;9 :: :
'`, "'
tween surfaces 52, 40 establishes a solid seal (best illustrated in Figure
10) between surface 14 of closure 16 and surface 20 of filler neck 22. -:
The following are illustrative dimensions for an 0-ring seal 10 of -~
the type illustrated in Figures 10-12; surface 36 axial length, 250 inch;
surface 38 axial length, (approximately~ .09 inch; web 30 radial thickness,
.120 inch; lips 26, 28 axial dimension from surface 38, .15 inch; axial dis- ~ .
tance from surface 52 to surface 62, .04 inch; minimum axial distance from
surface 32 to surface 42, .16 inch; axial length of surface 56 and surface
66, .06 inch; radial length of surface 52 or surface 62, .02 inch; outside :
dis~seter of ring 10, 2 i20hes; s2d, irgide dis~setsr of ring 10, 1.58 i20heg. ~
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