U.S. patent application number 09/836849 was filed with the patent office on 2002-10-17 for reservoir cap and cap assembly method.
Invention is credited to Arlt, George E., Sanderson, Rod.
Application Number | 20020148835 09/836849 |
Document ID | / |
Family ID | 25272883 |
Filed Date | 2002-10-17 |
United States Patent
Application |
20020148835 |
Kind Code |
A1 |
Arlt, George E. ; et
al. |
October 17, 2002 |
RESERVOIR CAP AND CAP ASSEMBLY METHOD
Abstract
The reservoir cap for a hydraulic fluid reservoir includes a cap
plate and an integral stick, a gasket, a cup and a spring. The
gasket is telescopically received on the stick and contacts a cap
gasket surface on the cap plate. The cup has two radially extending
ears with ramp contact surfaces and a central bore. The central
bore has two spaced apart flat cup bore surfaces and cup
projections that extend radially into the central bore. A coiled
compression spring has one end in contact with the cup and another
end in a spring retainer groove on the stick. The cup is mounted in
a preliminary position on shelves on the stick. Rotation of the
stick relative to the cup moves the cup off the shelves and the
spring moves the cup to a working position.
Inventors: |
Arlt, George E.; (Midland,
MI) ; Sanderson, Rod; (Midland, MI) |
Correspondence
Address: |
EDMUND P. ANDERSON
DELPHI TECHNOLOGIES, INC.
Legal Staff, Mail Code: 480-414-420
P.O. Box 5052
Troy
MI
48007-5052
US
|
Family ID: |
25272883 |
Appl. No.: |
09/836849 |
Filed: |
April 17, 2001 |
Current U.S.
Class: |
220/295 |
Current CPC
Class: |
B60T 11/26 20130101;
Y10T 29/4987 20150115 |
Class at
Publication: |
220/295 |
International
Class: |
B65D 041/06 |
Claims
What is claimed is:
1. A reservoir cap assembly for a fluid reservoir comprising: a cap
having a cap gasket surface; a stick extending from said cap along
a stick axis transverse to said cap gasket surface; a shelf
provided on said stick in axially spaced relation to said cap
gasket surface; a gasket disposed about said stick in contact with
said cap gasket surface; a cup having radially extending mounting
ears and a center passage through which said stick extends and a
shelf engaging surface; a spring urging said cup toward said cap
gasket surface; and wherein said cup is supported on said stick for
axial and rotational movement between a preliminary position in
which the shelf engaging surface is in contact with the shelf and
the spring applies force to the shelf and a working position in
which the spring applies force to the gasket.
2. A reservoir cap for a fluid reservoir as set forth in claim 1
including a surface on said stick that is parallel to the primary
flat surface and that is parallel to the stick axis and prevents
rotation of said cup relative to said stick when said cup is in the
working position.
3. A reservoir cap for a fluid reservoir as set forth in claim 2
including a second shelf on said stick and a second shelf engaging
surface on said cup.
4. A reservoir cap for a fluid reservoir as set forth in claim 1
wherein the spring is a coiled compression spring.
5. A reservoir cap for a hydraulic fluid reservoir comprising: a
cap plate with a cap gasket surface; a cap stick with a base
portion integral with the cap plate having a stick axis that is
perpendicular to the cap gasket surface and has a pair of primary
flat surfaces that are spaced apart and parallel to each other and
to the stick axis and extend axially away from the cap gasket
surface; a pair of shelves on the cap stick that are axially spaced
from and parallel with the cap gasket surface; a pair or secondary
flat surfaces on the stick that are spaced apart and parallel to
each other and to the stick axis, wherein each of the two secondary
flat surfaces start at one of the pair of shelves and extends away
from the pair of shelves and the cap gasket surface, and wherein
each of the secondary flat surfaces intersect one of the pair of
primary flat surfaces; a gasket that is telescopically received on
the stick and contacts the cap gasket surface; a cup having two
radially extending ears with ramp contact surfaces, with a pair of
parallel spaced apart flat cup bore surfaces that telescopically
receives the stick; a coil spring with an upper end that engages
the cup and a lower end that contacts a spring retainer on the
stick; and wherein the cup is urged into contact with the pair of
shelves on the cap stick when the stick is rotated to a preliminary
position relative to the cup and wherein the rotation of the stick
relative to the cup to a working position frees the cup to move off
the pair of shelves and toward the gasket.
6. A reservoir cap assembly method comprising: mounting a gasket on
a cap stick with the gasket in contact with a cap gasket surface
and with a stick of the cap stick passing through a bore through
the gasket; mounting a cup on at least one shelf on the stick;
mounting a spring on the stick to exert a force on the cup that
urges the cup toward the gasket; inserting the stick in a
reservoir; rotating said reservoir cap assembly to a closed
position; and rotating the cap stick relative to the cup to move
the cup off the at least one shelf and free the cup to move toward
the gasket.
Description
TECHNICAL FIELD
[0001] The invention relates to a hydraulic fluid reservoir cap
having a spring that applies a force to compress a seal between the
cap and a reservoir filler neck and to the reduction of a initial
cap mounting torque.
BACKGROUND OF THE INVENTION
[0002] Hydraulic fluid reservoirs have openings for checking the
hydraulic fluid level and for adding hydraulic fluid. It is
essential that the reservoir openings be closed to eliminate
hydraulic fluid contamination. Contaminants can damage hydraulic
system components such as pumps, valves and actuators. The sealing
of reservoir openings is particularly important for reservoirs on
vehicles, such as power steering reservoirs, due to their operating
conditions. Such reservoirs are subjected to moisture, dust,
abrasives, and various chemicals.
[0003] A hydraulic reservoir cap, that is currently used on
automotive vehicle reservoirs, has a cap with a cap stick. A gasket
is telescopically received on the cap stick. A cup member with a
pair of radially extending ears, is telescopically and
non-rotatably received on the cap stick. A coiled compression
spring has one end seated on the cup member and the other end
seated on a ledge on the cap stick so that the compression spring
urges the cup toward the gasket. When the reservoir cap is mounted
on a reservoir opening neck, in a closed position, the cup ears
contact an interior ramp surface on the reservoir opening neck, the
gasket contacts an exterior surface of the reservoir opening neck
and the gasket is compressed between the reservoir opening neck and
the gasket seat on the cap stick by the compression spring. As the
gasket wears the compression spring maintains a seal. The reservoir
cap is rotated about 125.degree. in one direction to close the
reservoir opening neck and in the opposite direction to open the
reservoir opening neck. A torque of about 2.3 Nm is required to
rotate the reservoir cap to a closed position or to an open
position. Most individuals can easily rotate the closure cap to an
open or to a close position without difficulty.
[0004] During assembly of hydraulic reservoirs, and prior to
shipment to vehicle assembly lines, a reservoir cap is placed on a
hydraulic reservoir and rotated to a closed position to keep
contaminants out of the reservoir. A person that installs several
thousand of the reservoir caps on the reservoirs during an
eight-hour shift will likely find a torque of about 2.3 Nm
tiring.
[0005] A tool which provides leverage and reduces the force
required to rotate a closure cap to a closed position has been
tried. Such a tool reduces the force required to produce a torque
of 2.3 Nm and reduces the chance of a repetitive stress injury.
Unfortunately the tool substantially increases the time required to
install a reservoir cap. The increased time required to install a
reservoir cap using a tool substantially reduces the number of
reservoir caps that can be installed in eight hours and increases
the cost of each of reservoir produced.
SUMMARY OF THE INVENTION
[0006] The reservoir cap for a fluid reservoir includes a cap plate
having a cap gasket surface. A cap stick has a base portion that is
integral with the cap plate. The cap stick has a stick axis that is
perpendicular to the cap gasket surface. A primary flat surface on
the cap stick is parallel to the stick axis and extends axially
away from the cap gasket surface. A shelf on the cap stick is
axially spaced from and parallel with the cap gasket surface. A
gasket is telescopically received on the cap stick and in contact
with the cap gasket surface. A cup has two radially extending ears
and a central bore with a flat cup bore surface. The central bore
telescopically receives the cap stick. A spring is in engagement
with the cup and the cap stick and urges the cup toward the cap
gasket surface. The cup is rotatable relative to the cap stick into
engagement with the shelf to hold the cup in a preliminary
position. The cup is rotatable out of engagement with the shelf to
free the cup to be moved toward the cap gasket surface and into a
working position by the spring.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] Presently preferred embodiments of the invention are
disclosed in the following description and in the accompanying
drawings, wherein:
[0008] FIG. 1 is an expanded perspective view of the reservoir
cap;
[0009] FIG. 2 is a perspective view of a hydraulic fluid reservoir
neck;
[0010] FIG. 3A is a bottom view of the reservoir cap with the cup
in a preliminary position on the shelf;
[0011] FIG. 3B is a sectional view taken along line 3-3 in FIG. 3A
with parts broken away;
[0012] FIG. 4A is a bottom view of the reservoir cap with the cup
in a working position; and
[0013] FIG. 4B is a sectional view taken along line 4-4 in FIG. 4A
with parts broken away.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENT
[0014] The reservoir cap 10 includes a cap stick 12, a gasket 14, a
cup 16 and a spring 18. The cap stick 12 includes a cap 20 and an
integral stick 22. The cap 20 has a cap plate 24 with a cap gasket
surface 26. The cap plate 24 has a gripping flange 28 on its
periphery 30 that extends axially downward from the cap plate.
[0015] The stick 22 has a base 32 that is integral with the cap
plate 24. The stick 22 also has a free end 34. The entire stick 22
as well as the cap 20 is symmetrical about a stick axis 36. The
base 32 is a cylindrical member 38 with two primary flat surfaces
40 and 42. The primary surfaces 40 and 42 are spaced apart and
parallel to each other and to the stick axis 36. Both primary
surfaces 40 and 42 extend axially downward from the cap plate 24 to
the base end 43. Shelves 44 and 46 on the base 32 are parallel to
and spaced from the cap gasket surface 26. Secondary flat surfaces
48 and 50 each extend downwardly from one of the shelves 40 and 46.
The secondary flat surfaces 48 and 50 are parallel to each other
and to the axis 36. The secondary flat surfaces 48 and 50 are
spaced apart a distance that is equal to the distance between the
primary flat surfaces 40 and 42. The primary flat surface 40 is
intersected by the secondary flat surface 48. The primary flat
surface 42 is intersected by the secondary flat surface 50. The
free end 34 of the stick 22 includes a truncated conical portion 52
and a spring retainer groove 54. The gasket 14 is a compressible
material with a center bore 56. The diameter of the center bore 56
is substantially the same as the diameter of the cylindrical member
38 of the stick 22.
[0016] The cup 16 has a plate portion 57 with outer skirts 58 and
60. A radially extending ear 62 on the outer skirt 58 has a ramp
contact surface 64. A radially extending ear 66 on the skirt 60 has
a ramp contact surface 68. A center passage 70 through the cup 16
is generally cylindrical with two flat cup bore surfaces 72 and 74.
An axial flange 76 surrounds the center passage 70 and reinforces
the cup 16.
[0017] The spring 18 is a coiled compression spring. The upper end
78 of the spring 18 engage the plate portion 57 of the cup 16 and
is radially positioned between the axial flange 76 and the skirts
58 and 60. The lower end 80 of the spring 18 is a small diameter
coil that is received in the spring retainer groove 54 of the cap
stick 12. During assembly the diameter of the small diameter coil
on the lower end 80 is increased as the spring 18 is forced over
the conical portion 52 of the stick 22. After the lower end 80 of
the spring 18 passes over the conical portion 52, it contracts into
the retainer groove 54.
[0018] The hydraulic fluid reservoir 79 has a cylindrical neck 81
with a filler opening 82. A sealing surface 84 is provided on the
outer end of the neck 81. Two cap holders 86 and 88 are fixed to
the inside cylindrical surface 90 of the neck 81. Both cap holders
86 and 88 are identical. An inlet end 92 of the cap holder 86 is
spaced 180.degree. from the inlet end 94 of the cap holder 88.
Block ends 96 and 98 of the cap holders 86 and 88 are spaced from
the inlet ends 92 and 94 of the adjacent cap holder. The spaces
between the block ends 96 and 98 and the inlet ends 92 and 94
provide axial cap ear passages 100 and 102.
[0019] Both cap holders 86 and 88 have ramp surfaces 104 that
extend from their inlet ends 92 and 94 to cup ear stop surfaces 105
adjacent to their block ends 96 and 98. Only the ramp surfaces 104
and the cap ear stop surfaces 105 on the cap holder 86 are shown in
the drawing. The cup ear stop surface 105 is a flat 5 radial
surface that is spaced from and faces away from the flat radial
surface on the block end 96 or 98.
[0020] The ramp surface 104 on the cup holder 86 includes an inlet
ramp 106, a retainer ramp 108 and a holder ramp 110. The inlet ramp
106 extends axially away from the sealing surface 84 from the inlet
end 94 to the ramp bottom 112. The retainer ramp 108 intersects the
inlet ramp 106 and extends axially upward from the ramp bottom 112
to the holder ramp 110. The holder ramp 110 is in a plane that is
parallel to the sealing surface 84.
[0021] During normal use of the hydraulic fluid reservoir 79, the
reservoir is closed by moving the radially extending ears 62 and 66
on the reservoir cap 10 axially into the cap ear passages 100 and
102 until the gasket 14 contacts the sealing surface 84. The
reservoir cap 10 is then rotated in a clockwise direction, as
viewed from above, to move the ramp contact surfaces 64 and 68 into
contact with the inlet ramps 106. Continued clockwise rotation of
the reservoir cap 10 moves the cup 16 off the gasket 14 and
shortens the axial length of the spring 18 until the radially
extending ears 62 and 66 move past the ramp bottoms 112. Continued
clockwise rotation of the reservoir cap 10 moves the ears 62 and 66
up the retainer ramps 108 and onto the holder ramps 110. The stop
surfaces 105 limit clockwise movement of the reservoir cap 10. The
retainer ramps 108 permit the spring 18 to expand slightly but
still compress the gasket 14 between the cap gasket surface 26 and
the sealing surface 84 and maintains a satisfactory seal.
[0022] The reservoir 79 is opened by rotating the reservoir cap 10
counterclockwise. Counterclockwise rotation moves the radially
extending ears 62 and 66 off the holder ramp 110, down the retainer
ramp 108, over the ramp bottom 112 and up the inlet ramp 106 to the
ear passages 100 and 102. After the block ends 96 and 98 stop
counterclockwise rotation of the reservoir cap 10, the cap is moved
axially away from the cylindrical neck 81 and the reservoir 79. The
torque required to rotate the reservoir cap counterclockwise down
the retainer ramps 108 and over the ramp bottom 112 is about the
same as the torque required to rotate the cap clockwise down the
inlet ramp 106 and over the ramp bottoms 112. This torque, as set
forth above, is acceptable for checking and adding hydraulic fluid.
However, it may be excessive on an assembly line where several
thousand caps 10 are manually rotated to a closed position during
each eight-hour shift.
[0023] During assembly of the reservoir cap 10 in the factory, the
gasket 14 is positioned on the base 32 of the stick 22 and in
contact with the cap gasket surface 26. The cup 16 is then placed
on the stick 22 with shelf engaging surfaces 59 on the plate
portion 57 setting on the shelves 44 and 46. The spring 18 is then
mounted on the stick 22 with the upper end 78 in engagement with
the cup 16 and the lower end 80 in the spring retainer groove 54.
In this position the spring 18 is compressed into a shortened
position. Friction resists rotation between the cup 14 and the cap
stick 12 and keeps the cup 16 on the shelves 44 and 46. The
reservoir cap 10 is then inserted axially into the cylindrical neck
81 until the gasket 14 contact the sealing surface 84 and the cap
gasket surface 26. The cap 10 is then rotated clockwise as viewed
from above. The radially extending ears 62 and 66 do not contact
the ramp surfaces 104 because the axial distance between the
shelves 44 and 46 and the cap gasket surface 26 exceeds the
thickness of the gasket 14 plus the axial distance from the ramp
bottoms 112 to the sealing surface 84. Continued clockwise rotation
of the cap stick 12, after the radially extending ears 62 and 66
contact the cup ear stop surfaces 105, rotates the cap stick 12
relative to the cup 16 and moves the cup off the shelves 44 and 46.
Once the cup 16 is off the shelves 44 and 46, the spring 18
expands, moves the ears 62 and 66 into contact with the holder
ramps 110, and moves the entire cup toward the cup gasket surface
26. This movement of the cup 16 compresses the gasket 14 between
the cup gasket surface 26 and the sealing surface 84 on the neck
81. The torque required to rotate the reservoir cap 10 when the cup
16 is on the shelves 44 and 46 and to release the cup from the
shelves, as explained above, is minimal. A person can perform the
operation to close the filler cap opening 82 and release the cup 16
from the shelves 44 and 46 thousands of times per day without
excessive stress.
[0024] The disclosed embodiments are representative of presently
preferred forms of the invention, but are intended to be
illustrative rather than definitive thereof. The invention is
defined in the claims.
* * * * *