U.S. patent application number 10/118675 was filed with the patent office on 2003-08-28 for disk oil slinger assembly.
Invention is credited to Burkholder, Robert F..
Application Number | 20030159888 10/118675 |
Document ID | / |
Family ID | 36386525 |
Filed Date | 2003-08-28 |
United States Patent
Application |
20030159888 |
Kind Code |
A1 |
Burkholder, Robert F. |
August 28, 2003 |
Disk oil slinger assembly
Abstract
A "splash" lubrication system having an oil slinger capable of
providing an increased flow rate of lubricating and cooling oil to
lubricated components of the system compared to conventional dip
stick oil slingers while reducing oil atomization and oil loss
through the crankcase vent is disclosed. In embodiments of the
invention, the oil slinger is comprised of a disk coupled to the
crankshaft assembly of the device being lubricated (e.g., an
engine, pump, compressor, or the like) so that rotation of the
crankshaft assembly rotates the disk for splashing lubricating oil
from the crankcase's oil sump onto the moving parts of the device
being lubricated by the lubricating system.
Inventors: |
Burkholder, Robert F.;
(Jackson, TN) |
Correspondence
Address: |
SUITER WEST PC LLO
14301 FNB PARKWAY
SUITE 220
OMAHA
NE
68154
US
|
Family ID: |
36386525 |
Appl. No.: |
10/118675 |
Filed: |
April 9, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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10118675 |
Apr 9, 2002 |
|
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09861285 |
May 18, 2001 |
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Current U.S.
Class: |
184/11.1 |
Current CPC
Class: |
F04B 39/0223 20130101;
F01M 9/06 20130101; F04B 41/02 20130101; F04B 39/0094 20130101;
F04B 39/0284 20130101; F16N 7/26 20130101 |
Class at
Publication: |
184/11.1 |
International
Class: |
F01M 001/00 |
Claims
What is claimed is:
1. A lubrication system for a device having a crankcase housing a
crankshaft assembly capable of rotation, comprising: an oil sump
suitable for containing lubricating oil for lubricating moving
components within the crankcase; and an oil slinger coupled to the
crankshaft assembly so that rotation of the crankshaft assembly
rotates the oil slinger for splashing lubricating oil from the oil
sump, wherein at least a portion of the oil slinger is continuously
submerged in the lubricating oil contained in the oil sump as it is
rotated by the crankshaft assembly.
2. The lubrication system as claimed in claim 1, wherein the oil
slinger is generally disk shaped.
3. The lubrication system as claimed in claim 2, wherein the oil
slinger comprises a shaped edge portion suitable for at least one
of increasing the amount of oil splashed from the oil sump and
directing oil splashed from the oil sump at an angle to the
disk.
4. The lubrication system as claimed in claim 2, wherein the oil
slinger comprises surface features suitable for at least one of
increasing the amount of oil splashed from the oil sump and
directing oil splashed from the oil sump at an angle to the
disk.
5. The lubrication system as claimed in claim 1, wherein the oil
slinger is coaxial with the crankshaft assembly.
6. The lubrication system as claimed in claim 1, wherein the oil
slinger comprises an auger.
7. The lubrication system as claimed in claim 1, wherein the oil
slinger is capable of extending into lubricating oil contained in
the oil sump when the crankcase is tilted
8. The lubrication system as claimed in claim 1, wherein the oil
slinger comprises a sector of a disk.
9. The lubrication system as claimed in claim 8, wherein the sector
rotates 360 degrees about the center of rotation of the crankshaft
assembly so that the oil slinger is capable of extending into
lubricating oil contained in the oil sump when the crankcase is
tilted.
10. The lubrication system as claimed in claim 1, wherein the
device includes at least two cylinder assemblies, each cylinder
assembly housing a piston assembly coupled to the crankshaft,
wherein the cylinder assemblies are oriented so that the oil
slinger is suitable for splashing lubricating oil from the oil sump
onto each piston assembly.
11. A lubrication system for a device having a crankcase housing a
crankshaft assembly capable of rotation and at least two cylinder
assemblies, each cylinder assembly housing a piston assembly
coupled to the crankshaft, comprising: means for containing
lubricating oil; and means, coupled to the crankshaft assembly, for
splashing lubricating oil from the containing means, wherein at
least a portion of the splashing means is continuously submerged in
the lubricating oil contained in the containing means, and wherein
the cylinder assemblies are oriented so that the splashing means is
suitable for splashing lubricating oil from the oil sump onto each
piston assembly.
12. The lubrication system as claimed in claim 11, wherein the
splashing means comprises a disk.
13. The lubrication system as claimed in claim 12, wherein the
splashing means comprises means for increasing the amount of oil
splashed from the containing means.
14. The lubrication system as claimed in claim 12, wherein the
splashing means comprises means for directing the flow of oil away
from the disk.
15. The lubrication system as claimed in claim 11, wherein the
splashing means is capable of extending into lubricating oil
contained in the containing means when the crankcase is tilted.
16. The lubrication system as claimed in claim 11, wherein
splashing means comprises a sector of a disk.
17. The lubrication system as claimed in claim 16, wherein the
sector rotates 360 degrees about the center of rotation of the
crankshaft assembly so that the splashing means is capable of
extending into lubricating oil contained in the containing means
when the crankcase is tilted.
18. A device, comprising: a crankcase housing a crankshaft assembly
capable of rotation; at least two cylinder assemblies; a piston
assembly housed in each cylinder assembly, the piston assemblies
being coupled to the crankshaft; an oil sump suitable for
containing lubricating oil for lubricating moving components within
the crankcase; and an oil slinger coupled to the crankshaft
assembly so that rotation of the crankshaft assembly rotates the
oil slinger for splashing lubricating oil from the oil sump, at
least a portion of the oil slinger being continuously submerged in
the lubricating oil contained in the oil sump as it is rotated by
the crankshaft assembly; wherein the cylinder assemblies are
oriented so that the oil slinger is suitable for splashing
lubricating oil from the oil sump onto each piston assembly.
19. The device as claimed in claim 18, wherein the oil slinger is
generally disk shaped.
20. The device as claimed in claim 18, wherein the oil slinger
comprises a shaped edge portion suitable for at least one of
increasing the amount of oil splashed from the oil sump and
directing oil splashed from the oil sump at an angle to the
disk.
21. The device as claimed in claim 18, wherein the oil slinger
comprises a surface feature suitable for at least one of increasing
the amount of oil splashed from the oil sump and directing oil
splashed from the oil sump at an angle to the disk.
22. The device as claimed in claim 18, wherein the oil slinger is
coaxial with the crankshaft assembly.
23. The device as claimed in claim 18, wherein the oil slinger
comprises an auger.
24. The device as claimed in claim 18, wherein the oil slinger is
capable of extending into lubricating oil contained in the oil sump
when the device is tilted at an angle to horizontal.
25. The device as claimed in claim 18, wherein the oil slinger
comprises a sector of a disk.
26. The device as claimed in claim 25, wherein the sector rotates
360 degrees about the center of rotation of the crankshaft assembly
so that the oil slinger is capable of extending into lubricating
oil contained in the oil sump when the crankcase is tilted.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a continuation-in-part of U.S.
patent application Ser. No. 09/861,285 filed May 18, 2001. Said
U.S. patent application Ser. No. 09/861,285 is herein incorporated
by reference in its entirety.
FIELD OF THE INVENTION
[0002] The present invention generally relates to the field of oil
lubrication devices for engines, compressors, pumps and the like,
and more particularly to a disk oil slinger suitable for use in oil
lubricated engines, compressors, pumps, and the like.
BACKGROUND OF THE INVENTION
[0003] Typically, lower cost oil lubricated engines, compressors,
pumps and the like have employed a "splash" lubrication system to
distribute oil from the oil sump to the mechanical bearings, seals,
valves, pistons and other parts that require lubrication and oil
cooling. A small protruding piece of material or "dip stick" is
attached to one or more of the moving components such that during
each revolution of the crankshaft, the dip stick dips into the oil
sump at sufficient velocity to cause oil to splash onto the
components requiring lubrication. The size, shape and velocity of
the dip stick must be engineered to assure sufficient lubrication
and oil cooling for all components while minimizing atomization of
the oil in the crankcase so as to reduce oil loss through the
crankcase vent. A higher velocity or larger profile dip stick will
improve lubrication and oil cooling but will increase oil
atomization and oil loss through the crankcase vent. A less
aggressive dipstick velocity or profile will reduce lubrication and
oil cooling but also reduce oil loss through the vent. These
conflicting phenomena require designers to compromise their design
by reducing the positive benefits of lubrication and oil cooling in
order to reduce the negative effects of oil loss.
[0004] Another problem with such traditional splash oil lubrication
systems is that the engines, compressors, pumps, and the like in
which such systems are used are employed in portable devices (e.g.,
compressors, generators, pressure washers, etc.) that are regularly
moved by hand from one work site to another. If such portable
devices are not properly leveled prior to operation, the dip stick
splash lubricator may not reach the oil sump causing a lack of
needed lubrication and cooling, possibly leading to subsequent
component failure.
[0005] Consequently, it would be advantageous to provide a "splash"
lubrication system designed to increase the flow rate of
lubricating and cooling oil to lubricated components while reducing
oil atomization and oil loss through the crankcase vent. Further,
it would be desirable to provide such a lubrication system that is
capable of functioning properly while the crankcase is tilted
providing an increased tolerance of operation on non-level
surfaces.
SUMMARY OF THE INVENTION
[0006] Accordingly, the present invention is directed to a "splash"
lubrication system having an oil slinger capable of providing an
increased flow rate of lubricating and cooling oil to lubricated
components of the system compared to conventional dip stick oil
slingers while reducing oil atomization and oil loss through the
crankcase vent. In embodiments of the invention, the oil slinger is
comprised of a disk coupled to the crankshaft assembly of the
device being lubricated (e.g., an engine, pump, compressor, or the
like) so that rotation of the crankshaft assembly rotates the disk
for splashing lubricating oil from the crankcase's oil sump onto
components of the device being lubricated. Preferably, at least a
portion of the oil slinger is continuously submerged in the
lubricating oil contained in the oil sump as it is rotated by the
crankshaft assembly, thereby decreasing atomization of oil from the
oil sump. Further, the oil slinger may be designed to remain at
least partially submerged in the oil sump even if the crankcase is
tilted providing increased tolerance of operation on non-level
surfaces.
[0007] In one embodiment the lubrication system may be implemented
in a device having two or more cylinder/piston assemblies. In such
embodiments, the cylinders of the device are oriented (e.g., may
overlap) so that a single oil slinger may provide lubrication to
both assemblies.
[0008] It is to be understood that both the forgoing general
description and the following detailed description are exemplary
and explanatory only and are not restrictive of the invention as
claimed. The accompanying drawings, which are incorporated in and
constitute a part of the specification, illustrate an embodiment of
the invention and together with the general description, serve to
explain the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The numerous advantages of the present invention may be
better understood by those skilled in the art by reference to the
accompanying figures in which:
[0010] FIG. 1 is an isometric view illustrating a lubrication
system in accordance with an exemplary embodiment of the present
invention;
[0011] FIG. 2 is a side elevational view illustrating the oil
slinger of the lubrication system shown in FIG. 1;
[0012] FIGS. 3 and 4 are side elevational views illustrating
tilting of the crankcase;
[0013] FIG. 5 is an isometric view illustrating a shaped disk oil
slinger having edge and/or surface features in accordance with an
exemplary embodiment of the present invention;
[0014] FIG. 6 is an isometric view illustrating an auger oil
slinger in accordance with an exemplary embodiment of the present
invention;
[0015] FIG. 7 is an isometric view illustrating an oil slinger in
accordance with an exemplary embodiment of the present invention
wherein the oil slinger is not a continuous disk; and
[0016] FIG. 8 is a partial cross-sectional side elevational view
illustrating a device having two cylinder/piston assemblies,
wherein the device employs the lubrication system of the present
invention.
DETAILED DESCRIPTION OF THE INVENTION
[0017] Reference will now be made in detail to the presently
preferred embodiments of the invention, examples of which are
illustrated in the accompanying drawings.
[0018] Referring now to FIGS. 1, 2, 3 and 4, an exemplary "splash"
lubrication system suitable for providing lubrication to the moving
components of devices such as engines, compressors, pumps, and the
like in accordance with the present invention is described. The
lubrication system 100 includes an oil sump 102 formed in the
crankcase 104 of the device 106 in which the lubrication system 100
is employed and an oil slinger 108 coupled to the device's
crankshaft assembly 110.
[0019] In one embodiment, the oil slinger 108 is comprised of a
continuous disk 112 attached to the crankshaft assembly 110.
Rotation of the crankshaft assembly 110 rotates the disk for
splashing lubricating oil 114 from the oil sump 102 onto components
of the device 108 being lubricated (e.g., crankshaft assembly 110,
journal 116, piston 118, cylinder wall 120, and the like).
Preferably, the disk 112 is positioned along the crankshaft
immediately adjacent to journal 116 so that oil may be slung from
the oil sump 102 onto the piston 118 and cylinder wall 120. For
instance, in one embodiment, shown in FIGS. 1 and 2, the disk 112
is bolted to a counterweight 122 of the crankshaft assembly 108 so
that it is centered coaxially with the center of rotation 124 of
the crankshaft assembly 110. The disk 112 may have an aperture 126
sized and shaped to fit over the crankshaft assembly 110 so that
the disk 112 and crankshaft assembly 110 may be assembled together.
However, it will be appreciated that other fabrication methods may
be employed without departing from the scope and spirit of the
present invention. For example, the disk 112 may be formed as an
integral part of the crankshaft assembly 110, or the crankshaft
assembly 110 may be formed in two or more sections that are joined
together around the disk 112, thereby clamping the disk 112 in
place.
[0020] During operation of the device 106, rotation of the
crankshaft assembly 110 rotates the oil slinger 108 for splashing
lubricating oil 114 from the oil sump 102 onto components of the
device 106 being lubricated (e.g., crankshaft assembly 110, journal
116, piston 118, cylinder wall 120, and the like). As shown, the
disk 112 of oil slinger 108 is generally centered coaxially with
the center of rotation 124 of the crankshaft assembly 110 so that
rotation of the crankshaft assembly 110 causes the disk 112 to
rotate 360 degrees about the center of rotation of the crankshaft
124. Thus, during operation, the lower portion of disk 112 is
continuously submerged in lubricating oil 114 contained in the oil
sump 102. Because the disk 112 remains in the oil 114 instead of
cyclically entering and exiting the oil 114, as does a conventional
dip stick or dipper oil slinger, the volume of oil 114 in the oil
sump 102 that the disk 112 displaces does not change during each
revolution of the crankshaft 110. Further, the oil slinger 108,
being a continuous disk 112, does not have a high speed advancing
edge that must pass through the lubricating oil 114 as do dipper
slingers. Thus, the flow of lubricating oil 114 over the surface of
the oil slinger 108 as it advances through the oil sump 102 is
substantially more laminar than is possible with intermittent
dipper slingers. As a result, the disk oil slinger 108 of the
present invention is capable of moving lubricating oil 114 about
the crankcase 104 with substantially less atomization of the oil
114.
[0021] The amount of oil flow generated by an oil slinger is
proportional to the surface area of the submerged portion of the
slinger, and proportional to the amount of time that the slinger is
submerged during each revolution of the crankshaft. Because the
lower portion of disk oil slinger 108 is continuously submerged in
the lubricating oil 114 contained in the oil sump 102, and the
submerged surface area of the disk 112 is substantially larger than
that of the dipper of a dipper oil slinger, the oil flow rate of
disk oil slinger 108 of the present invention is significantly
greater than that of an intermittent dipper slinger. For example,
lubrication systems 100 in accordance with the present invention
have been found to be capable of providing oil flows that are 50 to
100 times greater than lubrication systems utilizing dipper
slingers, while at the same time reducing atomization of the
lubricating oil 114 from the oil sump 102.
[0022] Turning now to FIGS. 3 and 4, the device 106 shown in FIGS.
1 and 2 is illustrated as being tilted at an angle to the
horizontal, for example, as if it were set on a non-level surface.
As shown, when the crankcase 104 is tilted, the surface of the
lubricating oil 114 in oil sump 102 remains substantially
horizontal. As shown, the disk 112 of oil slinger 108 is generally
centered coaxially with the center of rotation 124 of the
crankshaft assembly 110 so that rotation of the crankshaft assembly
110 causes the disk 112 to rotate 360 degrees about the center of
rotation of the crankshaft 124. As a result, the disk 112 remains
at least partially submerged in the oil sump 102 if the crankcase
104 is tilted providing an increased tolerance to unit operation on
non-level surfaces. It will be appreciated that the degree of tilt
(.alpha.) tolerated by lubrication system 100 may vary depending on
the design of crankcase 104, and is limited only by the possibility
of lubricating oil 114 from the oil sump 102 entering cylinder 118.
However, it is contemplated that degrees of tilt (.alpha.) of up to
or even greater than 90 degrees (i.e., the crankcase 102 is tilted
on its side) are possible.
[0023] Referring now to FIG. 5, a shaped oil slinger for a
lubrication system in accordance with an exemplary embodiment of
the invention is described. Shaped oil slinger 128 is comprised of
a disk 130 including an edge portion 132 shaped for generating
additional oil flow and/or for directing the oil flow at angles to
the side of the disk 130, thereby distributing the oil more
uniformly within the crankcase than conventional dipper type
lubrication systems. Further, the edge portion 132 may be shaped so
that it is capable of providing such advantages without
unnecessarily interrupting the laminar flow of the lubricating oil
around the disk 130, thus preventing unnecessary atomization of
lubricating oil from the oil sump (see FIG. 1). For instance, in
the embodiment shown in FIG. 4, edge portion 132 may be formed so
as to have a contour that is generally sinusoidal or curvilinear in
shape as viewed along an edge of the disk 130. Alternately, edge
portion 132 may be shaped to have other contours such as fins,
slots, grooves, or the like, depending on the requirements of the
particular application in which the lubrication system is
employed.
[0024] In addition to (or in place of) shaped edge portion 132,
features 134 may be formed on the surfaces of either or both sides
of disk 130 for providing additional oil flow and/or for directing
the oil flow at lateral angles to the disk 130. It will be
appreciated that the shape of such surface features 134 may vary
depending on the requirements (desired oil flow rate, splash
pattern, etc.) of the particular device in which the lubrication
system is employed. However, exemplary surface features 134 include
circumferential or spiraled ridges or grooves (shown), spaced
bumps, indentations, or slots, vanes, and the like. Additionally,
surface features 134 may be shaped so they do not create
unnecessary turbulence thereby interrupting the substantially
laminar flow of lubricating oil around the disk 130 and increasing
atomization of lubricating oil from the oil sump (see FIG. 1).
[0025] Referring now to FIG. 6, an auger oil slinger in accordance
with an exemplary embodiment of the present invention is shown. Oil
slinger 136 is comprised of a disk 138 having a slit 140 radially
formed therein from edge portion 142 toward the disk center 144.
The ends 146 & 148 of edge portion 142 adjacent to the slit 140
are separated laterally so that edge portion 142 assumes a
generally spiral shape. In this manner, disk 138 is formed into a
simple auger capable of generating substantially greater oil flow
than the dip stick slingers of conventional dipper lubrication
systems. The spiral shape of edge portion 142 may further direct
the oil flow at angles to disk 138 thereby distributing the oil
more uniformly within the crank case and providing greater coverage
of components of the device (see FIG. 1). Because disk 138 remains
substantially continuous except for leading and trailing edges 150
& 152 caused by slit 140, oil flow over the surface of the disk
138 is generally laminar. Thus, atomization of lubricating oil may
be held to rates that are substantially equal to or less than that
of conventional dipper lubrication systems.
[0026] Based on the discussion of the disk oil slingers shown in
FIGS. 1 through 6, it should now be appreciated that a substantial
advantage is obtained by increasing the surface area of the oil
slinger so that area of laminar flow is enlarged. In this manner,
cohesion of oil to the surface of the oil slinger is improved so
that the volume of oil "splashed" by the oil slinger as it rotates
is increased while atomization of the oil remains substantially
unchanged or is reduced. Thus, it should also be appreciated that
in accordance with the present invention, lubrication systems may
be provided that, while not utilizing continuous disk oil slingers,
provide enhanced performance compared to conventional "dip stick"
or dipper systems by substantially increasing the surface area of
the oil slinger to provide for more laminar flow of the lubricating
oil over the slinger as it is rotated.
[0027] Referring now to FIG. 7, an oil slinger in accordance with
such an alternate embodiment of the present invention is described.
Oil slinger 154 is comprised of a sector 156 of the full disk 112
of oil slinger 108 shown in FIGS. 1 through 4, having curvilinear
leading and trailing edges 158 & 160. Preferably, the angle
(.beta.) defining sector 156 is selected to provide sufficient
surface area so that the flow of lubricating oil over the oil
slinger 154 as it is rotated is substantially laminar except for
turbulence at leading and trailing edges 158 & 160. In this
manner, the volume of oil splashed by the oil slinger 154 is
substantially increased compared to conventional dipper oil
slingers, while the amount of atomization of lubricating oil
remains substantially equal to or less than such oil slingers.
[0028] In exemplary embodiments of the invention, the oil slinger
154 may be mounted to crankshaft assembly 110, shown in FIG. 1, so
that the disk 112 from which sector 156 is taken would be generally
centered coaxially with the center of rotation 124 of the
crankshaft assembly 110 if it were complete. In this manner,
rotation of the crankshaft assembly 110 causes the oil slinger 154
to rotate 360 degrees about the center of rotation of the
crankshaft 124. As a result, the oil slinger 154 remains capable of
being at least partially submerged in the oil sump 102 as it is
rotated even if the crankcase 104 is tilted. In this manner, the
oil slinger 154 is capable of providing an increased tolerance to
unit operation on non-level surfaces or in non-level
orientations.
[0029] Turning now to FIG. 8, implementation of a lubrication of
the present invention in a device having two or more
cylinder/piston assemblies is described. The lubrication system 200
includes an oil sump 202 formed in the crankcase 204 of the device
206 and an oil slinger 208 coupled to the device's crankshaft
assembly 210. Oil slinger 208 is comprised of a generally
continuous disk 212 attached to the crankshaft assembly 210.
[0030] In the exemplary embodiment shown, device 206 includes two
cylinder assemblies 214 & 216 housing piston assemblies 218
& 220 coupled to crankshaft assembly 210. Preferably, cylinder
assemblies 214 & 216 are oriented so that a single oil slinger
208 may provide lubrication to both assemblies. For example, as
shown in FIG. 8, cylinder assemblies 214 & 216 are oriented at
an angle of approximately ninety degrees to one another and spaced
so that they overlap thereby allowing a single plane 222, generally
coaxial with oil slinger 208, to intersect both cylinder assemblies
214 & 218. In this manner, single oil slinger may provide
lubricating oil 224 from the oil sump 202 onto each cylinder
assembly for lubricating components of each piston assembly 218
& 220 (e.g., eccentric bearings, wrist pin sets, etc.).
[0031] During operation of the device 206, rotation of the
crankshaft assembly 210 rotates the oil slinger 208 for splashing
lubricating oil 224 from the oil sump 202 for lubricating piston
assemblies 218 & 220 of both cylinder assemblies 214 & 216,
respectively. Like the embodiment shown in FIG. 1, the disk 212 of
oil slinger 208 is generally centered coaxially with the center of
rotation of the crankshaft assembly 210 so that rotation of the
crankshaft assembly 210 causes the disk 212 to rotate 360 degrees
about the center of rotation of the crankshaft 230.
[0032] It will be appreciated that, based on the foregoing
discussion, a device may be fabricated to comprise three or more
cylinder assemblies oriented to be lubricated by a single oil
slinger, such as oil slinger 208, without departing from the scope
and spirit of the invention. Moreover, in other embodiments,
devices may be provided having multiple cylinder/piston assemblies
that are lubricated by lubrication having two or more oil slingers
systems in accordance with the present invention. Again, such
embodiments would not depart from the scope and spirit of the
present invention.
[0033] It is contemplated that, employing the principles of the
invention discussed and illustrated herein, those of skill in the
art may now design lubrication systems utilizing oil slingers
having a wide variety of shapes (e.g., oval, eccentric, octagonal,
etc.) and/or edge and surface features other than those
specifically disclosed. Accordingly, such lubrication systems are
considered to be well within the scope and spirit of the present
invention as presently claimed. Further, it is believed that the
lubrication system of the present invention and many of its
attendant advantages will be understood by the forgoing
description, and it will be apparent that various changes may be
made in the form, construction and arrangement of the components
thereof without departing from the scope and spirit of the
invention or without sacrificing all of its material advantages,
the form herein before described being merely an explanatory
embodiment thereof. It is the intention of the following claims to
encompass and include such changes.
* * * * *