U.S. patent number RE31,058 [Application Number 06/179,121] was granted by the patent office on 1982-10-19 for seal and seal assembly.
This patent grant is currently assigned to Towmotor Corporation. Invention is credited to James H. Povejsil.
United States Patent |
RE31,058 |
Povejsil |
October 19, 1982 |
Seal and seal assembly
Abstract
A seal (16) has a body (38), a leg (40) and first and second
sealing areas (42,44). The seal (16) is used in a seal assembly
(10) having first and second members (12,14), such as, for example,
a frame portion (20) and steering knuckle (27) of a work vehicle.
Apparatus (28) such as bearing (30) supports the knuckle (27) in
rotation relative to a king pin (24) of the frame portion (20).
Foreign matter can enter between the frame portion (20) and
steering knuckle (27) and interfere with vehicle steering. In the
assembly (10), the sealing surfaces (42,44) contact substantially
perpendicular surfaces (32,34) of the frame portion (20) to block
passage of foreign matter to the bearing (30). A second end portion
(54) of the seal leg (40) can be controllably deflectable in order
to permit overfill of lubricant to pass from the bearing cavity
between the frame portion (20) and steering knuckle (27).
Inventors: |
Povejsil; James H. (Mentor,
OH) |
Assignee: |
Towmotor Corporation (Mentor,
OH)
|
Family
ID: |
26673477 |
Appl.
No.: |
06/179,121 |
Filed: |
August 18, 1980 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
Reissue of: |
004791 |
Dec 26, 1978 |
04210339 |
Jul 1, 1980 |
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Current U.S.
Class: |
277/552; 277/560;
305/100 |
Current CPC
Class: |
F16J
15/3232 (20130101); F16C 33/76 (20130101); F16C
33/723 (20130101); F16C 2326/24 (20130101) |
Current International
Class: |
F16C
33/76 (20060101); F16C 33/72 (20060101); F16J
15/32 (20060101); F16J 015/32 () |
Field of
Search: |
;277/92,95,152,153,165,205,26R ;308/36.1,187.1,187.2
;305/11,12 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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2708137 |
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Jun 1978 |
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DE |
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1139430 |
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Feb 1957 |
|
FR |
|
1531683 |
|
May 1968 |
|
FR |
|
1025884 |
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Apr 1966 |
|
GB |
|
1296020 |
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Nov 1972 |
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GB |
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Primary Examiner: Ward, Jr.; Robert S.
Attorney, Agent or Firm: Heming; William B.
Claims
I claim:
1. A seal (16), comprising:
a body (38);
a leg (40) having first, second and third sides (46,48,50), a
middle portion (56) and first and second end portions (52,54) and
being connected at the first end portion (52) to the body (38),
said first side (46) being linear .Iadd.and straight along its full
length .Iaddend.and generally opposed to said second side (48),
said second side (48) having a linear .Iadd.and straight
.Iaddend.portion (64) intersecting the third side (50) and being
.Iadd.oriented to extend .Iaddend.parallel to the first side (46)
and an arcuate portion (62) defining an arcuate surface (58)
extending curvilinearly inwardly in a direction generally toward
the first side (46) and defining a reduced cross-sectional area of
said leg (40) at the middle portion (56) relative to the second end
portion (54), said third side (50) being .[.linear.].
.Iadd.straight along its full length .Iaddend.and intersecting said
first and second sides (46,48) at the second end portion (54), said
second end portion (54) being of a construction sufficient for
being controllably deflectable relative to said first end portion
(52) in response to a force exerted on at least one of the first
and third sides (46,50); and
first and second sealing areas (42,44) positioned on said leg (40)
adjacent the intersection of the first and third sides (46,50), and
the intersection of the second and third sides (48,50),
respectively.
2. The seal (16), as set forth in claim 1, wherein said first and
second sealing areas (42,44) are located at the intersection of the
first and third sides (46,50) and second and third sides (48,50),
respectively.
3. The seal (16), as set forth in claim 1, wherein said seal (16)
has only a single leg (40).
4. The seal (16), as set forth in claim 1, wherein said third side
(50) intersects the first side (46) at an angle (A.sub.1) of about
90.degree..
5. The seal (16), as set forth in claim 1, wherein said third side
(50) intersects the second side (48) at an angle .[.(50).].
.Iadd.(A.sub.2) .Iaddend.of about 90.degree.. .[.6. The seal (16),
as set forth in claim 1, wherein said third side (50) is
substantially linear..]. .[.7. The seal (16), as set forth in claim
1, wherein said first side (56) is substantially linear..]. .[.8.
The seal (16), as set forth in claim 1, wherein said first side
(46) of the leg (40) is substantially parallel to
said linear portion (64) of the second side (48)..]. 9. The seal
(16), as set forth in claim 1, wherein said .[.first.].
.Iadd.second .Iaddend.sealing area .[.(42).]. .Iadd.(44)
.Iaddend.is on said leg (40) at a location immediately adjacent a
point (66) on said second side (48) from which said arcuate surface
(58) extends inwardly toward said first
side (46). 10. The seal (16), as set forth in claim 1, wherein said
leg (40) has a width (W.sub.1) defined by the distance between the
first and second sides (46,48) and the arcuate surface (58) of said
second side (48)
extends inwardly about one-half of said width (W.sub.1). 11. The
seal (16), as set forth in claim 1, wherein said arcuate surface
(58) extends outwardly from the middle portion (56) toward the
first end portion (52) in a direction from the first side (46) and
intersects the body (38) of the seal (16) at a location (60) at
which said leg (40) connects at the
second side (48) to said body (38). 12. The seal (16), as set forth
in claim 1, wherein the length .[.(L.sub.1).]. .Iadd.(L.sub.2)
.Iaddend.of the linear portion (64) of the second side (48) is
about one-third the length .[.(L.sub.2).]. .Iadd.(L.sub.1)
.Iaddend.of the first side (46).
The seal (16), as set forth in claim 1, wherein said seal (16) has
a
carrier element (68) connected to the body (38). 14. The seal (16),
as set forth in claim 1, wherein said body (38), leg (40) and first
and second
sealing areas (42,44) are of unitary, elastomeric construction. 15.
The seal (16), as set forth in claim 1, wherein said seal (16) is
of an
annular configuration. 16. The seal (16), as set forth in claim 1,
including means (63) for biasing said second end portion (54) of
the leg (40) relative to said first end portion (52) of the leg
(40) in a direction (D.sub.1) from the second .[.(34).]. .Iadd.(48)
.Iaddend.toward
the first side .[.(32).]. .Iadd.(46) .Iaddend.of the leg (40). 17.
The seal (16), as set forth in claim 16, wherein said biasing means
(63) is a spring (65) positioned on the second side .[.(34).].
.Iadd.(48)
.Iaddend.of the leg (40). 18. A seal assembly (10) for blocking
passage of foreign matter through an annular opening (36),
comprising:
a first member (12) having first and second surfaces (32,34)
oriented substantially perpendicular one relative to the other;
a second member (14) positioned adjacent said first member (12),
said first and second members (12,14) being rotatable one relative
to the other and defining the annular opening (36) between said
second member (14) and the first and second surfaces (32,34) of
said first member (12);
means (28) for supporting said first and second members (12,14) in
rotation one relative to the other.Iadd., said means (28) being a
bearing (38) positioned between said first and second members
(12,14) in said annular opening (36) .Iaddend.;
a seal body (38) connected to said second member (14) and
positioned adjacent and extending about said annular opening
(36);
a seal leg (40) having first, second and third sides (46,48,50) and
first and second end portions (52,54) and being connected at the
first end portion (52) to the body (38) and extending outwardly
from said body (38) about .Iadd.and across .Iaddend.the annular
opening (36) and in a direction toward said first and second
surfaces (32,34) of the first member (14) .Iadd.to form a first
channel (90) adjacent the bearing (30) and a second channel (92)
exposed to the environment.Iaddend., said first and second sides
(46,48) being generally opposed, said third side (50) intersecting
said first and second sides (46,48) at the second end portion (54),
said second end portion (54) being of a configuration sufficient
for being controllably deflectable in response to a force exerted
on at least one of the first and third sides (46,50) of said leg
(40); and
first and second sealing areas (42,44) positioned on said leg (40)
adjacent the intersection of the first and third sides
.[.(46,48).]. .Iadd.(46,50) .Iaddend.and the second and third sides
(48,50), respectively, and being in sealing, slidable contact with
said first surface (32) and said second surface (34), respectively,
of the first member (12) at a location sufficient for blocking
access .Iadd.of the foreign matter .Iaddend.through the annular
opening (36) .Iadd.from the second channel (92) into the first
channel (90) to the bearing (30) .Iaddend.in response to forces
exerted on the second side (48) of the leg (40), said first and
second sealing areas (42,44) being both removable together from
contact with said respective first and second surfaces (32,34) of
the first member .[.(14).]. .Iadd.(12) to relieve lubricant flow at
the bearing (30) and in the first channel (90) through the annular
opening (36) into the second channel (92) .Iaddend.in response to
controllably deflecting said second
end portion (54). 19. The seal assembly (10), as set forth in claim
18, wherein said leg (40) has a middle portion (56) and said second
side of the leg (40) is of a configuration sufficient for defining
a reduced crosssectional area of said leg (40) at the middle
portion (56) relative
to the second end portion (54) of said leg (40). 20. The seal
assembly (10), as set forth in claim 19, wherein said second side
(48) has an arcuate surface (58) extending curvilinearly inwardly
from the second end portion (54) toward the middle portion (56) in
a direction generally
toward the first side (46). 21. The seal assembly (10), as set
forth in claim 18, wherein the first and second sealing areas
(42,44) are located at the intersection of the first and third
sides (46,50) and the second
and third sides (48,50), respectively. 22. The seal assembly (10),
as set forth in claim 18, wherein said seal assembly (10) has only
a single leg
(40). 23. The seal assembly (10), as set forth in claim 18,
including a line (78) passing through said first and second sealing
areas (42,44), said line (78) intersecting the first surface (32)
of the first member (12) at an angle (A.sub.5) in a range of about
45.degree. to about
90.degree.. 24. The seal assembly (10), as set forth in claim 23,
wherein
said angle (A.sub.5) is about 45.degree.. 25. The seal assembly
(10), as set forth in claim 23, wherein said third side (50)
defines the line (78) passing through said first and second sealing
surfaces (42,44). .[.26. The seal assembly (10), as set forth in
claim 18, wherein said first side (46) intersects the first surface
(32) of the first member (12) at an angle
(A.sub.6) of about 60.degree...]. 27. The seal assembly (10), as
set forth in claim 20, wherein said second side (48) has a
substantially linear .Iadd.and straight .Iaddend.portion (64)
intersecting the third side (50) and an arcuate portion (62)
defining the arcuate surface (58) of said
second side (48). 28. The seal assembly (10), as set forth in claim
27, wherein said linear .Iadd.and straight .Iaddend.portion (64) of
the second side (48) intersects the second surface (34) of the
first member (12) at
an angle (A.sub.7) of about 60.degree.. 29. The seal assembly (10),
as set forth in claim 18, wherein said first and second surfaces
(32,34) of the first member (12) define first and second
substantially perpendicular intersecting planes (32',34'),
respectively, and including a line (78) passing between said first
and second sealing areas (42,44), said line (78) defining a chord
(80) of a circle (82) having a radial line (84), said radial line
(84) substantially bisecting said chord (80) and passing
immediately adjacent the intersection (86) of said planes
(32',34'). 30. The seal assembly (10), as set forth in claim 27,
.Iadd.wherein .Iaddend.said first side (46) of the leg (40) is
substantially parallel to said linear .Iadd.and straight
.Iaddend.portion (64) of the second side
(48). 31. The seal assembly (10), as set forth in claim 18, wherein
said first and second sealing areas (42,44) urge against said first
and second
surfaces (32,34) of the first member (12), respectively. 32. The
seal assembly (10), as set forth in claim 18, wherein said seal
body (38), leg (40) and first and second sealing areas (42,44) are
of unitary,
elastomeric construction. 33. The seal assembly (10), as set forth
in claim 18, wherein the third side (50) of the leg (40) extends
between said first and second sealing areas (42,44) and said leg
(40) forms an annular chamber (88) with said first member (12),
said annular chamber (88) being defined by the first and second
surfaces (32,34) of said first member (12) and the third side (50)
of the leg (40). .[.34. The seal assembly (10), as set forth in
claim 33, wherein the leg (40) forms first and second channels
(90,92) with said first member (12), said first and second channels
(90,92) being defined by the first side (46) of the leg (40) and
first surface (32) of the first member (12) and the second side
(48) of the leg (40) and the second surface (34) of the first
member (12), respectively, and being of a construction sufficient
for being positionable in communication one with the other in
response to removing the first and second sealing areas (42,44)
from contact with the first and
second surfaces (32,34), respectively..]. 35. The seal assembly
(10), as set forth in claim 18, including means (63) for biasing
the second end portion (54) of the leg (40) relative to the first
end portion (52) of the leg (40) in a direction (D.sub.2) toward
the first surface (32) of the
first member (12). 36. The seal assembly (10), as set forth in
claim 35, wherein said biasing means (63) is a spring (65)
positioned on the second side (48) of the leg (40).
Description
DESCRIPTION
1. Technical Field
The invention relates to a seal and seal assembly. More
particularly, the invention relates to a leg of a seal which is
controllably deflectable and has first and second sealing areas in
slidable contact with substantially perpendicular surfaces in the
seal assembly.
2. Background Art
In the use of a seal and seal assembly, it is desirable to block
passage of foreign matter in one direction but to permit deflection
of the seal in another direction to, for example, allow overfilling
a bearing with lubricant to clean the bearing.
U.S. Pat. No. 4,043,620 which issued to Otto on Aug. 23, 1977,
discloses configurations of bearing seals used to seal openings
between a housing and a rotatable shaft.
U.S. Pat. No. 3,687,464 which issued to Jackson et al on Aug. 29,
1972, discloses a seal which has a U-shaped cross-section and is
used to seal against a shaft and a housing perpendicularly oriented
to the shaft. U.S. Pat. No. 3,841,723 which issued on Oct. 15,
1974, to Kelso shows a seal having a dust lip and a spring biased
seal lip.
For example, a steering assembly for a work vehicle commonly
includes an axle or frame mounted king pin about which a steering
knuckle is rotatable. Rotation of the steering knuckle provides
corresponding rotation of a spindle to controllably turn a wheel of
the vehicle attached thereto. The steering knuckle is supported
about the king pin by a bearing which must be protected and
periodically lubricated to assure proper performance of the
steering assembly.
The bearing is exposed to the environment of the work vehicle
through an opening located between the steering knuckle and axle
owing to the relative rotation of the two components. Heretofore, a
seal having two lips or legs and being connected to the steering
knuckle has been used. The two lips contact or seal against a
surface on the frame or axle to block passage of foreign matter to
the bearing. However, when lubricant is subsequently injected into
the bearing said seal also blocks passage of the lubricant out of
the bearing. In situations where the bearing is overfilled, such as
to drive old lubricant from the bearing, this can cause damage to
the seal or improper performance of the steering assembly. The
result is a waste of time and labor owing to the reduced
performance of the steering assembly or downtime in replacing the
seal.
Therefore, it is desirable to provide a seal which blocks passage
of foreign matter in one direction, such as to the bearing, and
controllably deflects in another direction to permit lubricant
overfill of the bearing to relieve for substantially preventing
damage to the seal as a result of the overfill.
DISCLOSURE OF INVENTION
In one aspect of the present invention, a seal has a body and a leg
connected at a first end portion to the body. The leg has first,
second and third sides and a second end portion of a construction
sufficient for being controllably deflectable in response to a
force exerted on at least one of the first and third sides. The
seal has first and second sealing areas positioned on the leg
adjacent the intersection of the first and third sides and second
and third sides, respectively.
In another aspect of the present invention, a seal assembly has
first and second members. The first member has first and second
surfaces oriented substantially perpendicular one relative to the
other. The second member is positioned adjacent said first member.
A seal body is connected to the second member. A seal leg is
connected to the body and extends outwardly from said body. First
and second sealing areas are positioned on said leg. The first
sealing area is in slidable contact with the first surface of the
first member. The second sealing area in slidable contact with the
second surface of the second member.
The first and second members of the seal assembly are, for example,
a frame portion and a steering knuckle, respectively. The steering
knuckle is supported relative to the frame portion by a bearing. In
operation of an associated work vehicle, foreign matter can pass
between the frame portion and steering knuckle and interfere with
the bearing. The seal blocks passage of the foreign matter and is
also controllably deflectable to permit passage of lubricant
overfill from the bearing for cleaning said bearing.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a diagrammatic view showing one embodiment of the seal
assembly of the present invention associated with a steering
mechanism;
FIG. 2 is a diagrammatic partial view of FIG. 1 showing the
invention in greater detail;
FIG. 3 is a diagrammatic cross-sectional view showing one
embodiment of the seal of the present invention; and
FIG. 4 is a diagrammatic view showing another embodiment of the
seal and seal assembly of the present invention associated with a
steering mechanism.
BEST MODE FOR CARRYING OUT THE INVENTION
Referring to FIG. 1, a seal assembly 10 includes first and second
members 12,14 rotatable one relative to the other and a seal 16.
The first member 12 is, for example, a frame portion 20 of a work
vehicle 21. Said frame portion 20 includes an axle 22, king pin 24
and a spacer 26. The second member 14 is, for example, a steering
knuckle 27 of the work vehicle which is positioned adjacent said
frame portion 20. The steering knuckle 27 is rotatable about the
fixed frame portion 20 in response to input forces exerted in
steering the work vehicle 21. Means 28, shown as a bearing 30, is
provided for supporting said frame portion 20 and the steering
knuckle 27 in rotation one relative to the other. Such wheel
steering construction is well known in the vehicle art.
The frame portion 20 has first and second surfaces 32,34 oriented
substantially perpendicular one relative to the other and defined
by the spacer 26 and axle 22, respectively. The frame portion 20
and steering knuckle 27 define an annular opening 36 between said
steering knuckle 27 and said first and second surfaces 32,34. The
seal 16 in the seal assembly 10 is annular in configuration and is
positioned at a location sufficient for controllably sealing the
passage of material through said annular opening 36 as will be
hereinafter described.
Referring particularly to FIG. 3, the seal 16 includes a body 38, a
leg 40 and first and second sealing areas 42,44. The leg 40 has
first, second and third sides 46,48,50, first and second end
portions 52,54 and a middle portion 56. Said leg 40 is connected at
the first end portion 52 to the body 38 and extends outwardly from
said body 38. The first and .[.second sides 46,48 are
substantially.]. .Iadd.third sides 46,50 are .Iaddend.linear.[.,
and generally opposed one to the other.]. .Iadd.straight along
their full lengths.Iaddend.. The third side 50 intersects the first
and second sides 46,48 at the second end portion 54 preferably at
respective angles A.sub.1,A.sub.2 of about 90.degree.. Said seal 16
preferably has only a single leg 40 as shown.
The first and second sealing areas 42,44 are each positioned on the
leg 40 adjacent the intersection of the first and third sides 46,50
and the intersection of the second and third sides 48,50,
respectively. Said sealing areas 42,44 are preferably located at or
formed by the intersection of the first and third sides 46,50 and
the second and third sides 48,50 respectively.
The second end portion 54 of the leg 40 is of a construction
sufficient for being controllably deflectable relative to the first
end portion 52 in response to a force exerted on at least one of
the first and third sides 46,50 of the leg 40. In the embodiment
shown, the second side 48 of the leg 40, which is generally opposed
to the first side 46, is of a configuration sufficient for defining
a reduced cross-sectional area of said leg 40 at the middle portion
56 relative to said second end portion 54. The reduction in
cross-sectional area, as further defined below by the configuration
of said second side 48, provides controllable deflection of the
second end portion 54 for the purposes hereinafter discussed.
The second side 48 of the leg 40 has an arcuate surface 58
extending curvilinearly inwardly on said leg 40 from the second end
portion 54 toward the middle portion 56 in a direction generally
toward the first side 46. The leg 40 has a width at W.sub.1 defined
by the distance between the first and second sides 46,48 and the
arcuate surface 58 extends inwardly at the middle portion 56 about
one-half of said width (shown at W.sub.2). In other words, the
second side 48 extends curvilinearly inwardly and progressively
reduces the cross-sectional area of the second leg 40 from the
second end portion 54 toward the middle portion 56. Thus, the
cross-sectional area adjacent W.sub.2 is less than the
cross-sectional area adjacent W.sub.1. It is also desirable that
said arcuate surface 58 further extend curvilinearly outwardly from
the middle portion 56 toward the first end portion 52 of the leg 40
in a direction from the first side 46 and intersect the body 38 at
a location 60 at which the leg 40 connects at the second side 48 to
the body 38.
The second side 48 has an arcuate portion 62 defining the arcuate
surface 58 of said second side 48 and a substantially linear
.Iadd.and straight .Iaddend.portion 64 intersecting the third side
50 of the leg 40 and which is preferably substantially parallel to
the first side 46 of said leg 40. Said linear portion 64 has a
length .[.(L.sub.1).]. .Iadd.L.sub.2 .Iaddend.about one-third the
length .[.L.sub.2 .]. .Iadd.L.sub.1 .Iaddend.of the first side 46
in order to maintain sufficient width at the second end portion 54
of the leg 40 for adequate rigidity of the seal 16 in position in
the seal assembly 10 against the first and second surfaces 32,34 of
the frame portion 20. Further, the .[.first.]. .Iadd.second
.Iaddend.sealing area .[.42.]. .Iadd.44 .Iaddend.is positioned on
the leg 40 at a location immediately adjacent a point 66 on the
second side 48 from which the arcuate surface 58 extends inwardly
toward the first side 46.
Referring to the embodiment of FIG. 4, means 63 is provided for
biasing the second end portion 54 of the leg 40 relative to the
first end portion 52 of said leg 40 in a direction D.sub.1 from the
second side 48 toward the first side 46 of the leg 40. Said biasing
means 63 is shown as a spring 65, such as a helical spring,
positioned on the second side 48 of the leg 40 and retained in a
groove 67 formed in the arcuate portion 62 of said second side 48.
In an annular configuration of the seal 16, which is the preferred
embodiment, the spring 65 tends to bias .[.outwardly.]. against and
about said second side 48 to urge said first and second sealing
areas 42,44 into contact with the first and second surfaces 32,34
when the seal 16 is positioned in the seal assembly 10. Said
biasing means 63 can also be, for example, a ring or similar
element which tends to expand .[.outwardly.]. against the second
side 48.
The body 38, leg 40 and first and second sealing areas 42,44 are
preferably of unitary, elastomeric construction. The seal 16 also
has a carrier element 68 connected or molded to the body 38 on at
least first and second sides 70,72 of said body .[.40.].
.Iadd.38.Iaddend.. The carrier element 68 is of metallic
construction as is known in the art. The first and second sides
46,.[.50.]..Iadd.48 .Iaddend.of the leg 40 intersect third and
fourth sides 74,76 of the body 38 and define the orientation of the
leg 40 relative to the body 38 as shown. It should be understood
that the seal 16 can be of other configurations as is known in the
art without departing from the invention.
In the installed position of the seal 16 in the seal assembly 10,
the seal body 38 is connected to the steering knuckle 27 and
positioned adjacent and extending about the annular opening 36. In
the embodiment shown, said seal 16 is press fit into a
substantially circular bore 77 defined by the steering knuckle 27
owing to the oversize configuration of the metallic carrier element
68. The first sealing area 42 is positioned in sealing, slidable
contact with the first surface 32 of the frame portion 20. The
second sealing surface 44 is positioned in sealing slidable contact
with the second surface 34 of the frame portion 20. It is desirable
that the second end portion 54 of the leg 40 be controllably
deflectable as above described with respect to the individual seal
16. The first and second sealing areas 42,44 are thus removable
from contact with the first and second surfaces 32,34,
respectively, in response to controllably deflecting the second end
portion 54.
A line 78 passing between the first and second sealing areas 42,44
intersects the first surface 32 of the frame portion 20 at an angle
A.sub.5 in a range of about 45.degree. to about 90.degree.. The
third side 50 extends between said sealing areas 42,44 and defines
said line 78. The angle A.sub.5 in the preferred embodiment is
about 45.degree.. In other words, said line 78 passing between the
sealing areas 42,44 defines a chord 80 of a circle 82 having a
radial line 84. The radial line 84 substantially bisects the chord
80 and passes immediately adjacent the intersection 86 of first and
second planes 32', 34' defined by the first and second surfaces
32,34 of the frame portion 20. As is also shown, the first side
.[.42.]. .Iadd.46 .Iaddend.of the leg 40 intersects the first
surface 32 of the frame portion 20 at an angle A.sub.6 .[.of about
60.degree..].. The linear portion 64 of the second side .[.44.].
.Iadd. 48 .Iaddend.intersects the second surface 34 of the frame
portion 20 at an angle A.sub.7 of about 60.degree..
It is desirable that the first and second sealing areas 42,44 urge
against the first and second surfaces 32,34 of the frame portion
20, respectively, in order to maintain a positive "seal" against
said surfaces 32,34. The biasing means .[.65.]. .Iadd.63
.Iaddend.or spring .[.67.]. .Iadd.65 .Iaddend.in the embodiment of
FIG. 4 biases the second end portion 54 of the leg 40 relative to
the first end portion 52 of the leg 40 in a direction D.sub.2
toward the first surface 32 of the frame portion 20 to assure the
positive "seal". Said direction D.sub.2 is shown substantially the
same as the direction D.sub.1. The positive "seal" can also be
assured by preloading the leg 40. In other words, the orientation
of the first side 46 of the leg 40, as represented by angle
A.sub.3, (FIG. 3) can be provided in the seal 16 such that said
first side 46 is displaced from said angle A.sub.3 to an
installation angle A.sub.4 (FIG. 2) when the seal 16 is in the
installed position. Thus, angle A.sub.3 is provided less than angle
A.sub.4 to establish the preloaded condition.
On the .[.sealed.]. .Iadd.seal .Iaddend.assembly 10, the leg 40
forms an annular chamber 88 with the frame portion 20. The annular
chamber 88 is defined by the first and second surfaces 32,34 of
said frame portion 20 and the third side 50 of the leg 40. The leg
40 also forms first and second channels 90,92 with said frame
portion 20. Said first and second channels 90,92 are defined by the
first side .[.42.]. .Iadd.46 .Iaddend.of the leg 40 and the first
surface of the frame portion 20 and the second side .[.44.].
.Iadd.48 .Iaddend.of the leg 40 and the second surface 34 of the
frame portion 20, respectively. Said channels 90,92 are of a
construction sufficient for being positionable in communication one
with the other in response to removing the first and second sealing
areas 42,44 from contact with the first and second surfaces 32,34
respectively.
It is desirable that in the seal assembly 10 the second end portion
54 of the leg 40 be controllably deflectable relative to the first
end portion 52 of the leg 40, as was explained previously with
respect to the seal 16. Also, the configuration of said seal 16 is
preferably also as above explained with respect to the seal 16. The
first and second sealing areas 42,44 are removable from contact
with the first and second surfaces 32,34 of the frame portion 20,
respectively, in response to controllably deflecting said second
end portion 54, as is shown by way of example in FIG. 1. The
channels 90,92 are in fluid communication one with the other in
response to exerting a force on at least one of the first and third
sides 46,50 of the leg 40 for deflecting said second end portion
54.
It should be understood that the seal 16 and seal assembly 10 can
be of other configurations as is known in the art without departing
from the invention.
INDUSTRIAL APPLICABILITY
In the use of the seal 16 in the seal assembly 10, the first and
second sealing areas 42,44 slidably contact the first and second
surfaces 32,34 of the frame portion 20 to block passage of foreign
matter through the annular opening 36 and to the bearing 30.
Overfill of lubricant in the bearing 30 controllably deflects the
second end portion 54 of the leg 40 to relieve lubricant through
the annular opening 36 to clean the bearing 30.
For example, input forces on the steering knuckle 27 through a
steering arm 93 cause said knuckle 27 to rotate relative to the
frame portion 20. In rotation the first and second sealing surfaces
42,44 wipe or slide along the frame portion 20 to prevent passage
of dirt, water of the like through the annular opening 36 to the
bearing 30. Thus, the bearing 30 is substantially protected from
the effects of the environment of the work vehicle 21. Said sealing
surfaces 42,44 remain seated on the surfaces 32,34 of the frame
portion 20 and the second end portion 54 of the leg 40 resists
deflection from forces exerted on the seal 16 by dirt or the like
owing to the substantially linear configuration of the first side
46 of the leg 40 and its orientation relative to the frame portion
20.
After a period of use of the steering of the vehicle, it may be
desirable to relubricate said bearing 30. The bearing 30 is
commonly overfilled to permit flushing of the old lubricant from
the bearing 30. As the lubricant passes through the bearing 30, it
will urge initially against the first side 46 of the leg 40 and
exert a force on said first side 46. Where the force is sufficient,
the second end portion 54 of the leg 40 will deflect about the
point of intersection of the first side 46 of the leg 40 and the
body 38 owing to the curvilinear configuration of the second side
48 of the leg 40 and the corresponding reduction in cross-sectional
area. Deflection of the second end portion 54 removes the sealing
surfaces 42,44 from contact with the frame portion 20. The
lubricant then flows from the first channel 90 through the annular
chamber 88 and out the second channel 92. This action is
represented by flow lines 94 in FIG. 1.
Force is also exerted on the third side 50 of the leg 40 during
overfill. This tends to promote relief or escape of the lubricant
from the bearing 30. Where the first and second sealing surfaces
32,34 urge against the frame portion 20, the relief of said
lubricant tends to slow owing to the greater force required to
overcome, for example, the spring 65 or preload of the leg 40.
Following overfill some lubricant will be trapped in the annular
chamber 88 and will act as an additional barrier to foreign matter.
It should be understood that a force exerted on only the third side
50 of the leg 40 will also deflect the seal 16.
The first and second sealing areas 42,44 preferably are represented
by points of contact such as are formed by the intersections of the
first and third sides 46,50 and second and third sides 48,50 of the
.[.legs.]. .Iadd.leg .Iaddend.40, respectively, to reduce friction
between the seal 16 and frame portion 20. The first sealing area 42
will, however, tend to wear a groove into the first surface 32
during operation of the vehicle steering. The wearing action on the
first sealing area 42 results in movement of the second sealing
.[.surface 34.]. .Iadd.area 44 .Iaddend.toward the first surface
32, but does not interfere substantially with the performance of
the seal 16.
The preferred orientation and configuration of the seal 16 is shown
in the drawings. The third side 50 intersects the first surface 32
at the angle A.sub.5 which is about 45.degree.. The .[.first side
46 and.]. linear portion 64 of the second side 48 .[.intersect.].
.Iadd.intersects .Iaddend.the .[.first and.]. second .[.surfaces
32,34, respectively, at angles A.sub.6,.]..Iadd.surface 34 at an
angle .Iaddend. A.sub.7 of about 60.degree.. It will be evident
from a study of the drawings that other orientations or
configurations of the seal 16 will to some degree lessen or
increase the effect of the deflection and sealing capabilities of
the seal 16. For example, a greater angle A.sub.5 tends to reduce
the capabilities of seal 16 to relieve the lubricant flowing
through the bearing 30 owing to a reduction in the size of the
relief pathway available to said lubricant.
Other aspects, objects and advantages will become apparent from a
study of the specification, drawings and appended claims.
* * * * *