Engine oiling distribution system for purging air and method of use

Information

  • Patent Grant
  • 6435146
  • Patent Number
    6,435,146
  • Date Filed
    Monday, October 23, 2000
    23 years ago
  • Date Issued
    Tuesday, August 20, 2002
    22 years ago
Abstract
The present invention includes an oiling distribution system having an oil distribution manifold for evenly distributing engine oil to the cylinders of an internal combustion engine and an adapter base for coupling to the oil distribution manifold having therein an air purging passage for purging any air accompanying the oil exiting an oil pumping system. The air purging passage discharges air to the oil distribution manifold wherein the air is transported to the fuel system of an internal combustion engine through a fuel system oiling outlet. The air purging passage has an air inlet and air outlet that are sufficient size to allow the transport of air but minimize the flow of oil through the air purging passage. The present invention also provides a method for purging air from an oiling system.
Description




BACKGROUND OF THE INVENTION




The present invention relates generally to oiling systems for internal combustion engines, and more specifically, to an air purging system for use with a two-stroke internal combustion engine.




Typically, two-stroke outboard marine engines did not have a separate oiling system. That is, these prior art engines required pre-mixing lubricant and fuel so that the lubricant dissolves in the fuel to lubricate the engine. This required consistent, accurate measuring and agitation of the mixture. There are many disadvantages to the prior art system of pre-mixing lubricant and fuel. For example, since various two-stroke engines require different mix concentrations, many outboard marine engine owners who also own other two-stroke engine equipment, such as various lawn and garden equipment and ATV's, may store several different concentrations of oil/fuel mixture. This is not only an aggravation to the owner, but is also problematic if the containers become mixed up and the owner uses the wrong concentration for a particular two-stroke engine. While this is not catastrophic, if run over time with the wrong concentration, a two-stroke engine wears excessively.




The present invention is for use in a unique lubrication system for two-stroke engines. Such a lubrication system must not only provide lubrication to each cylinder of the engine, it must also provide lubrication to the fuel system to properly lubricate the fuel metering and injection system. As is well known, air entrained in the oil, can hinder a properly operating lubrication system. It is therefore desirable to remove any air from the oil, while preventing any such air in the oil system from being fed to the cylinders of the engine. As is known, air in such a system can prevent oil flow, especially where check valves are used, resulting in a phenomena known as “air lock.” If an oil passage becomes air locked, the operator would have no way of knowing that the affected cylinder is not receiving sufficient oil, and continued operation of the engine will result in severe damage to that particular cylinder.




It would therefore be desirable to have an air purging system that can purge air from the oil system while providing oil to the fuel system components.




SUMMARY OF THE INVENTION




The present invention provides an oiling distribution system for an oil pumping system of an internal combustion engine. The system includes an oil distribution manifold for distributing engine oil to each cylinder of an internal combustion engine. The oil distribution manifold further includes a fuel system outlet that purges air from the oil distribution manifold along with oil to the fuel system of the internal combustion engine. The system also includes an adapter having therein an air purging passage in an internal chamber. The air purging passage allows air entrained in the oil entering the internal chamber to be transported to the oil distribution manifold. All of which overcome the aforementioned drawbacks.




In accordance with one aspect of the invention, a base to adapt an oil distribution system to an oil pumping system of an internal combustion engine is provided. The base includes an oil outlet end in fluid communication with the oil distribution system. The base also includes a check valve located between the oil inlet end and the oil outlet end to regulate the flow of pressurized oil to the oil outlet end and an air purging passage that allows air entrained in the pressurized oil to escape to the oil distribution manifold through an air outlet. The air purging passage includes the air outlet in the oil outlet end and an air inlet in the oil inlet end. The oil inlet end is in fluid communication with the oil pumping system.




In accordance with another aspect of the invention, an oil distribution manifold and an oiling system adapter base coupled thereto are provided. The oil distribution manifold and the oiling system adapter base form an oiling distribution system for use with a two-stroke internal combustion engine. The oil distribution manifold includes a plurality of cylinder oiling outlets to supply oil to each cylinder of an engine and a fuel system oiling outlet to supply oil and any air in the oil system to a fuel system of the internal combustion engine. The oiling system adapter base which is coupled to the oil distribution manifold includes a cylindrical chamber and a bleed slot to purge air from the cylindrical chamber to the fuel system oiling outlet.




The invention also includes a method for purging air to a fuel system of an internal combustion engine. The method includes supplying oil to an internal passage having a check valve therein and periodically allowing oil to open the check valve and pass through the internal chamber. As air may accumulate when the check valve is closed, the method further includes bleeding air through a bleed slot and routing the air through the bleed slot to a fuel system of an internal combustion engine.




Another aspect of the present invention is to provide a method for bleeding air from the oil system of an internal combustion engine wherein a distribution manifold includes a centrally located dome having a plurality of cylinder outlet outlets and a fuel system outlet is coupled to an adapter having a cylinder chamber and a bleed slot. The method further includes the step of providing an air outlet port in communication with a fuel system outlet port. Oil from an oil pumping system is injected into a frusto-conical oil inlet port of the adapter. A check valve housed within a cylindrical chamber of the adapter regulates the flow of oil to the distribution manifold. The method then bleeds air entrained in the oil through the bleed slot between the check valve and the oil inlet port to the oil distribution manifold.




Various other features, objects and advantages of the present invention will be made apparent from the following detailed description and the drawings.











BRIEF DESCRIPTION OF THE DRAWINGS




The drawings illustrate one preferred embodiment presently contemplated for carrying out the invention.




In the drawings:





FIG. 1

is a perspective view of an oiling distribution system as assembled for use with a two-stroke outboard marine engine.





FIG. 2

is a top view of a distribution manifold used in the oiling distribution system of FIG.


1


.





FIG. 3

is a front elevational view of the oiling distribution system shown in FIG.


1


.





FIG. 4

is a cross-section top view of the distribution manifold of

FIG. 3

taken along line


4





4


of FIG.


3


.





FIG. 5

is a cross-sectional side view of the oiling distribution system of FIG.


3


.





FIG. 6

is a cross-sectional view of a portion of the oiling distribution system taken along line


6





6


of FIG.


5


.





FIG. 7

is a cross-sectional top view of a portion of the oiling distribution system taken along line


7





7


of FIG.


5


.





FIG. 8

is a cross-sectional view of a portion of the oiling distribution system taken along line


8





8


of FIG.


6


.











DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT




The operating environment of the present invention herein is described with respect to two-cycle outboard marine engines. However, it will be appreciated by those of ordinary skill in the art that the present invention is equally applicable for use with other types of internal combustion engines, such as diesel engines, using a distribution manifold for distributing engine oil to a plurality of cylinders and a fuel system.




Referring to

FIG. 1

, an oiling distribution system


10


includes a distribution manifold


12


having a plurality of cylinder outlet housings


14


for each cylinder of a two-stroke internal combustion engine, such as those used for outboard marine engines. In this embodiment, distribution manifold


12


has six outlets


14


, one for each cylinder of a six cylinder engine and a fuel system oiling outlet housing


16


. The manifold


12


is mounted to an oil system adapter


18


shown coupled to the manifold


12




18


with mounting bolts


12




a,




12




b.


The oil system adapter


18


is mounted to the engine


20


through mounting bores


18




a,




18




b.


Oil is introduced into the oil system adapter


18


in oil inlet


22


from an oil pumping system (not shown). The adapter


18


includes a cylindrical chamber


23


. A vacuous tube


24


extends from the cylindrical chamber


23


downwardly to the base of the adapter


18


. An oil pressure switch can be inserted in a pressure switch port


25


that is on the underside of the adapter


18


. The vacuous tube


24


allows air in the pressure switch port


25


to be transported to the cylindrical chamber


23


.





FIG. 2

shows a top view of the distribution manifold


12


for use with a two-stroke internal combustion engine. The cylinder outlet housings


14


are angled equidistantly about a centrally-located dome


38


, preferably, at an angle of incidence of 28 degrees. The cylinder outlet housings


14


, as well as the fuel system oiling outlet housing


16


, each contain a push-to-connect fitting


40


,


42


. The push-to-connect fittings


40


for the cylinder outlet housings


14


retain a hose


44


in fluid communication with each cylinder of the internal combustion engine. The push-to-connect fitting


42


for the fuel system oiling outlet housing


16


also retains a hose


46


in fluid communication with a fuel separator (not shown) of the fuel system. The push-to-connect fittings


40


,


42


are designed to prevent leakage, allow easy coupling of the hoses


44


,


46


, lock the hoses


44


,


46


to the manifold outlets


15


,


16


, and allow easy decoupling of the hoses


44


,


46


when needed.




Referring now to

FIG. 3

, the fuel system outlet housing


16


is shown preferably positioned at a higher elevation than the cylinder outlet housings


14


to purge air from the distribution manifold


12


and the oiling system


10


. The positioning of the fuel system oiling outlet housing


16


above the cylinder outlet housings


14


allows air that accumulates in dome


38


to purge through the fuel system oiling outlet housing


16


to the fuel separator where it is vented to the atmosphere. As shown, the cylinder outlet housings


14


share a plane that is significantly below the plane of the fuel system oiling outlet housing


16


. The adapter


18


is shown coupled to the manifold


12


using mounting bolts


12




a


and


12




b.


The adapter


18


is then bolted to an oil source housing, such as an engine


20


. As further shown the pressure switch port


25


includes a push-to-connect fitting


40


to retain a pressure switch and/or plug (not shown) therein.





FIG. 4

illustrates an enlarged, cross-sectional view of the distribution manifold


12


of the oiling system


10


. The cylinder outlet housings


14


and the fuel system oiling outlet housing


16


each include an oiling check valve


48


that regulates the flow of oil from the centrally-located dome


38


to the cylinders and fuel system of the internal combustion engine, respectively. The cylinder outlet housings


14


extend from a side edge


50


of the centrally-located dome


38


whereas the fuel system oiling outlet housing


16


extends from an apex


52


of the centrally-located dome


38


. Two mounting bores


54




a,




54




b


are provided in manifold


12


to receive mounting bolts


12




a,




12




b,



FIG. 1

, to secure the distribution manifold


12


to the oil system adapter


18


.




The push-to-connect fittings


40


,


42


include a seal


66


that prevents leakage between the housing


16


and the push-to-connect fittings


40


,


42


. A ring sleeve


68


supports an internal gripping ring


70


. The gripping ring


70


positively clamps a hose in position in the housings


14


,


16


. The push-to-connect fittings


40


,


42


also include a barbed retaining sleeve


72


to hold the push-to-connect fittings


40


,


42


securely within the housings


14


,


16


. The push-to-connect fittings


40


,


42


further include a release mechanism


74


, that when depressed, releases the gripping ring


70


to allow the hose to be removed. The release mechanism


74


of the push-to-connect fittings


40


,


42


thus allows for a quick disconnection of the hose, which is otherwise firmly-secured by the gripping ring


70


. A preferred fitting is a ¼″ nickel-plated Legris Carstick® fitting made by Legris, Inc.




The oiling check valves


48


each contain a locking ring


76


to lock the oiling valve within the housings


14


,


16


. The oiling check valves


48


include a check ball


78


and a spring


80


to bias the check ball


78


against a check valve seat


82


. Pressure from the oil against the check ball


78


accumulates until it exceeds an opposing bias force from the spring


80


, at which point the spring


80


compresses and unseats the check ball


78


to permit oil to flow around the check ball


78


in a first direction


84


through the oiling check valves


48


and through the outlet housings


14


,


16


. The oiling check valves


48


prevent oil flow backward, or around the check ball


78


in a direction opposite to the flow path


84


. In this manner, fuel from the fuel system is prevented from entering the oil distribution system


10


. Upon biasing the check ball


78


of the oiling check valve


48


within the fuel system oiling outlet housing


16


, the oil and air are free to flow to the fuel system separator.





FIG. 5

is a cross-sectional side view of the oiling distribution system


10


shown with the oil distribution manifold


12


coupled to the oil system adapter


18


. As shown, the oil inlet


22


has a frusto-conical shape. By utilizing a frusto-conical oil inlet


22


, the flow of oil from the oil pumping system is regulated. Moreover, the frusto-conical shape allows the oil inlet


22


to force any air entrained in the oil upstream toward the cylindrical chamber


23


. Further, using an oil inlet


22


having a frusto-conical shape eliminates pockets for potential accumulation of air entrained in the oil.




Still referring to

FIG. 5

, the oil pressure switch port


25


further includes a push-to-connect fitting


40


similar to the other push-to-connect fittings that are inserted into each of the plurality of cylinder oiling outlets


14


and the fuel system outlet


16


. As shown, the vacuous chamber


24


intersects the cylindrical chamber


23


and extends downwardly towards the oil pressure switch port


25


. One of ordinary skill in the art will appreciate that use of the vacuous chamber


24


and the pressure switch port


25


are not a pre-requisite for full implementation of the present invention. As such, the vacuous chamber


24


could be plugged at an inlet end


27


. Further, the push-to-connect fitting


40


could be removed from the pressure switch port


25


and the port closed off during the molding process of oil system adapter


18


or, a plug can be installed into the push-to-connect fitting


40


to close off the pressure switch port


25


.





FIG. 6

is an enlarged view of the cylindrical chamber


23


taken along lines


6





6


of FIG.


5


. The cylindrical chamber


23


includes a check valve


90


that regulates the flow of oil from the oil inlet


22


toward the oil distribution manifold


12


. The cylindrical chamber check valve


90


contains a locking ring to lock the cylindrical chamber check valve within the cylindrical chamber


23


. The cylindrical chamber check valve


90


includes a check ball


94


and a spring


96


to bias the check ball


94


against a check valve seat


97


. Pressure from the oil against the check ball


90


accumulates until it exceeds an opposing bias force from the spring


96


, at which point the spring


96


compresses and unseats the check ball


94


to permit oil to flow around the check ball


94


in a first direction


100


through the cylindrical chamber check valve


90


toward the oil distribution manifold


12


. The cylindrical chamber check valve


90


prevents oil flow backwards, or around the check ball


94


in a direction opposite to the flow path


100


. In this manner, oil in the oil distribution manifold


12


is prevented from flowing back to the oil pumping system.




Extending parallel to the cylindrical chamber check valve


90


is an air purging passage


102


having an air outlet


104


. An air inlet


105


receives air entrained in the pressurized oil that is then allowed to escape through the air purging passage


102


and discharged to the oil distribution manifold


12


through the air outlet


104


. The air purging passage


102


is sized to allow air passage, yet restrict oil flow therethrough.




Now referring to

FIG. 7

, which is taken along lines


7





7


of

FIG. 5

, the oil system adapter


18


is shown without the check valve


48


in the cylindrical chamber


23


. The oil inlet


22


extends upwardly to the cylindrical chamber


23


so as to form a cylindrical chamber check valve stop


106


. Extending along the surface of the stop


106


is the air inlet


108


that intersects the air purging passage


102


which runs parallel along the inner wall


110


of the cylindrical chamber


23


. The inner cylindrical wall


110


extends upwardly so as to form a recessed circular section


112


between the inner cylindrical wall


110


and an outer cylindrical wall


114


. An O-ring (not shown) is then placed in the recessed section


112


to create a seal when coupling the adapter


18


to the oil distribution manifold


12


. To ensure proper alignment of the oil distribution manifold


12


when coupling to the oil system adapter


18


, a notch


116


is provided in an upper surface


117


of the adapter


18


. The notch


116


extends upwardly from the upper surface


117


and is received into an opening (not shown) on the oil distribution manifold


12


.




The relative position of the check valve stop


106


and the air purging passage


102


in the adapter


18


is further shown in FIG.


8


. Taken along line


8





8


of

FIG. 6

,

FIG. 8

shows the air purging passage


102


positioned along the surface of the check valve stop


106


and extending up the side of the adapter


18


. The air inlet passage


102


is teardrop shaped which, together with its size, minimizes oil passage, yet allows air to escape therethrough.




The present invention discloses an oiling distribution system


10


for use with a two-stroke internal combustion engine. The system


10


includes an oil distribution manifold


12


having a plurality of cylinder oiling outlets


14


to supply oil to each cylinder of the internal combustion engine as well as a fuel system oiling outlet


16


to supply oil to the fuel system of the internal combustion engine. The system further includes an oiling system adapter base


18


that when coupled to the oil distribution manifold


12


allows air entrained in the oil exiting an oil pumping system of an internal combustion engine to be discharged in the oil distribution manifold


12


and expunged to the fuel system separator through the fuel system oiling outlet


16


. The oiling system adapter base


18


includes a cylindrical chamber


23


housing a check valve


90


to regulate the flow of oil to the oil distribution manifold


12


as well as an air urging passage


102


having an air inlet


108


and an air outlet


104


for discharging air entrained in the oil to the oil distribution manifold


12


.




Accordingly, a method for purging air entrained in oil entering an oil distribution manifold


12


is provided. Oil is supplied to an internal chamber


23


having a check valve therein


90


that is periodically allowed to open when a check ball


94


is biased against a valve seat


92


by a spring


96


when oil pressure is at a predetermined value. Opening of the check valve


90


allows oil exiting the oil pumping system to pass through to an oil distribution manifold


12


. To avoid air entrained in the pressurized oil from accumulating against the check ball


94


of the check valve


90


, it is necessary to then purge or bleed the air through the air purging passage


102


which has an air outlet


104


in the oil distribution manifold


12


. The method then discharges the air deposited in the oil distribution manifold


12


through the fuel system of the internal combustion engine through the fuel system oiling outlet


16


.




The present invention has been described in terms of the preferred embodiment, and it is recognized that equivalents, alternatives, and modifications, aside from those expressly stated, are possible and within the scope of the appending claims.



Claims
  • 1. A base to adapt an oil distribution system to an oil pumping system of an internal combustion engine comprising:an oil inlet end in fluid communication with an oil system; an oil outlet end in fluid communication with an oil distribution system; a check valve located between the oil inlet end and the oil outlet end to regulate the flow of pressurized oil to the oil outlet end; an air purging passage having an air outlet in the oil outlet end and an air inlet in the oil inlet end, wherein air entrained in the pressurized oil is allowed to escape through the air purging passage; and an oil inlet having a frusto-conical configuration to receive pressurized oil and air and to regulate the flow of oil and air from the oil pumping system to the check valve.
  • 2. The base of claim 1 wherein the oil distribution system includes an oil distribution manifold and the air purging passage is arranged parallel to the check valve and allows air to escape from the oil inlet end to the oil distribution manifold.
  • 3. The base of claim 2 wherein the check valve comprises a valve seat and a spring to bias a check ball against the valve seat at a predetermined pressure.
  • 4. The base of claim 2 wherein the oil distribution manifold further comprises:a number of cylinder oiling outlets, the number of which corresponds to a number of cylinders in the internal combustion engine, and a fuel system oiling outlet.
  • 5. The base of claim 4 wherein the number of cylinder oiling outlets are in fluid communication with a centrally located dome.
  • 6. The base of claim 5 wherein the fuel system oiling outlet is positioned at a height axially above the number of cylinder oiling outlets.
  • 7. The base of claim 4 wherein each of the number of cylinder oiling outlets are equidistant from one another.
  • 8. An oiling distribution system for use with a two-stroke internal combustion engine comprising:an oil distribution manifold having a plurality of cylinder oiling outlets to supply oil to each cylinder of an engine and a fuel system oiling outlet to supply oil to a fuel system of the engine; and an oiling system adaptor base having a cylindrical chamber coupled to the oil distribution manifold and a bleed slot to purge air from the cylindrical chamber to the fuel system oiling outlet.
  • 9. The oiling distribution system of claim 8 wherein the bleed slot is configured parallel to the cylindrical chamber and is sized large enough to allow air passage and small enough to minimize oil passage.
  • 10. The oiling distribution system of claim 9 wherein the check valve comprises a valve seat and a spring to bias a check ball against the valve seat at a predetermined pressure and the bleed slot has an opening in an internal wall of the oiling system adapter base and runs parallel with the check valve.
  • 11. The oiling distribution system of claim 9 wherein the oil outlet is in fluid communication with the oil distribution manifold and the oil inlet is in fluid communication with an oil pumping system.
  • 12. The oiling distribution system of claim 8 wherein the cylindrical chamber further comprises an oil transport chamber formed by an oil outlet in an oil outlet end and an oil inlet in an oil inlet end, wherein the oil transport chamber includes a check valve between the oil inlet and the oil outlet, and the bleed slot is an air by-pass to the check valve.
  • 13. The oiling distribution system of claim 8 wherein the bleed slot further comprises an air outlet end having an air outlet in communication with the fuel system oiling outlet and an air inlet end having an air inlet in communication with the cylindrical chamber of the oiling system adaptor base.
  • 14. The oiling distribution system of claim 13 wherein the air inlet receives air in the cylindrical chamber and allows the air to escape through the bleed slot to be transported upstream to the air outlet, wherein the air outlet discharges the air to the oil distribution manifold.
  • 15. The oiling distribution system of claim 8 wherein the oil distribution manifold further comprises a centrally located dome having a notch along an upper interior surface therein, wherein the notch is configured to receive air from the bleed slot.
  • 16. The oiling distribution system of claim 15 wherein the notch is further configured to be in communication with the fuel system oiling outlet.
  • 17. The oiling distribution system of claim 16 wherein the fuel system oiling outlet is positioned at a height axially above the plurality of cylinder oiling outlets.
  • 18. The oiling distribution system of claim 8 wherein the oiling system adaptor base further comprises a pressure sensing switch and a vacuous chamber communicating with the cylindrical chamber to allow passage of any air from the pressure sensing switch to the cylindrical chamber.
  • 19. A method for purging air to a fuel system of an internal combustion engine, comprising the steps of:supplying oil to an internal chamber having a check valve therein; periodically allowing oil to open the check valve and pass through the internal chamber; bleeding air that may accumulate in the internal chamber when the check valve is closed through a bleed slot; routing the air through the bleed slot and to a fuel system of an internal combustion engine; and configuring the bleed slot to bypass around thc internal chamber.
  • 20. The method of claim 19 wherein the step of periodically allowing oil to open the check valve further includes the step of biasing a check ball with a spring against a valve seat.
  • 21. The method of claim 19 further comprising the step of releasing air from the internal chamber to a manifold.
  • 22. The method of claim 19 further comprising the step of providing a frusto-conical oil inlet to regulate the flow of oil to the internal chamber, wherein the oil inlet is in fluid communication with an oil pumping system of the internal combustion engine.
  • 23. A method for bleeding air from an oil system of an internal combustion engine comprising the steps of:configuring a distribution manifold comprising a centrally located dome having a plurality of cylinder outlet ports and a fuel system outlet port; providing an air outlet port in communication with the fuel system outlet port; coupling to the distribution manifold an adaptor having a cylindrical chamber including a check valve, and a frusto-conical oil inlet port, and a bleed slot, wherein the bleed slot communicates with the air outlet port; and connecting the adaptor to an oil pumping system.
  • 24. The method of claim 23 further comprising the step of purging air entrained between the check valve and the oil inlet port, wherein the step of purging further includes the step of directing air to an air inlet of the bleed slot.
  • 25. The method of claim 23 further comprising the step of transporting air in the bleed slot to bypass the check valve and the step of discharging the air through the air outlet port to the fuel system outlet port.
  • 26. The method of claim 23 wherein the steps of configuring an adaptor further includes the steps of providing a pressure activation switch and a vacuous chamber to transport any air from the pressure activation switch to the cylindrical chamber.
  • 27. A base to adapt an oil distribution system to an oil pumping system of an internal combustion engine comprising:an oil inlet end in fluid communication with an oil system; an oil outlet end in fluid communication with an oil distribution system; a check valve located between the oil inlet end and the oil outlet end to regulate the flow of pressurized oil to the oil outlet end; an air purging passage having an air outlet in the oil outlet end and an air inlet in the oil inlet end, wherein air entrained in the pressurized oil is allowed to escape through the air purging passage; and wherein the oil distribution system includes an oil distribution manifold and wherein the air purging passage allows air to escape from the oil inlet end to the oil distribution manifold.
  • 28. The base of claim 27 wherein the air purging passage is arranged parallel to the check valve.
  • 29. The base of claim 27 wherein the check valve comprises a valve seat and a spring to bias a check ball against the valve seat at a predetermined pressure.
  • 30. The base of claim 27 wherein the oil distribution manifold further comprises:a number of cylinder oiling outlets, the number of which corresponds to a number of cylinders in the internal combustion engine, and a fuel system oiling outlet.
  • 31. The base of claim 30 wherein the number of cylinder oiling outlets are in fluid communication with a centrally located dome.
  • 32. The base of claim 30 wherein the fuel system oiling outlet is positioned at a height axially above the number of cylinder oiling outlets.
  • 33. The base of claim 30 wherein each of the number of cylinder oiling outlets are equidistant from one another.
  • 34. The base of claim 27 wherein the oil inlet has a frusto-conical configuration to receive pressurized oil and air and to regulate the flow of oil and air from the oil pumping system to the check valve.
US Referenced Citations (3)
Number Name Date Kind
5145328 Harwath Sep 1992 A
5297511 Suzuki Mar 1994 A
5941745 Kanno Aug 1999 A