Dual action air pump

Information

  • Patent Grant
  • 6299420
  • Patent Number
    6,299,420
  • Date Filed
    Thursday, April 6, 2000
    24 years ago
  • Date Issued
    Tuesday, October 9, 2001
    23 years ago
Abstract
An air pump is a dual action manually driven with a piston and two intake and two exhaust check values that respectively operate with one intake port and one exhaust port. These check valves operate in tandem with each other during each pumping stroke, either up or down. During each pumping stroke, one intake check valve and one exhaust check valve are open with their counterparts closed, to provide continuous discharge of compressed air through the exhaust port and also to provide continuous intake of air through the intake port. The air pump includes a cylindrically shaped hollow reservoir housing, a base connected to one end of the housing, an intake port and an exhaust or inflate port which are mounted on the base, an elongated piston shaft extending along the longitudinal axis of the housing, and a handle perpendicularly disposed with respect to the piston shaft to assist pumping of the piston shaft.
Description




BACKGROUND OF THE INVENTION




1. Field of the Invention




The present invention relates to an air pump, and more particularly, to a dual action air pump which can inflate and deflate at the same time and inflate an inflatable object during both up and down stroke to provide continuous discharge of compressed air.




2. Discussion of the Related Art




Children enjoy playing in inflatable toy structures, such as inflatable houses and above-the-ground pools. Conventional inflatable toy structures are inflated by using a manual or foot operated air pumps. The user of a manual air pump, such as a bicycle tire pump or inflatable toy pump, generally encounters difficulties in inflating a pneumatic article, such as a toy structure or tire. When commencing the pumping process, the article has a low (ambient) or no pressure and it is desirable to pump as large a volume of air as possible into the article with each pumping stroke. The user's difficulty at this stage is that many pumping strokes are required unless the volume of air per stroke is large. Conventional single action air pumps discharge the air inside through the air outlet only during the down stroke of the piston shaft. During the upstroke of the piston shaft, outside air is sucked into the air pump through an air inlet but no air is discharged through the air outlet.




Most manual or foot operated air pumps use the check valve concept to control the flow of air into their reservoirs and the subsequent discharging or exhausting of the air from the reservoir into the object being inflated. Check valves are necessarily provided in the air inlet and air outlet in order to control the air flow in a single direction. As an example, foot operated bellows pumps are normally spring loaded and operate with one intake and one exhaust check value. During the compression of the bellows air chamber (or reservoir) air exhausts into the object being inflated and during the spring-back, or up cycle, air refills the reservoir.




Additionally, it is a common manual air pump industry design to have this type of air pump inflate, but not deflate, an object on both the up and down strokes of the pumping cycle. These types of air pumps are commonly referred to as a double or dual action air pumps, and normally have their reservoir cylindrically shaped with intake check valves located at the opposite ends of the cylinder. As the pumping stroke drives the air out of either end of the cylinder, the opposite side check valve opens to allow the opposite side air to be replenished. During the pumping action where air on either side of a piston head is being compressed, the compressed air inflates the intended object by flowing through a side slit in a hollow piston shaft to which a hose is attached that is connected to the object to be inflated.




SUMMARY OF THE INVENTION




Accordingly, the present invention is directed to a dual action air pump that substantially obviates one or more of the problems due to limitations and disadvantages of the related art.




An object of the present invention is to provide an air pump that is used to inflate and deflate an inflatable object by changing a hose to appropriate air port opening.




Another object of the present invention is to provide an air pump that provides a continuous flow of air to an inflatable object during both up and down stroke of the piston shaft.




Another object of the present invention is to provide an air pump that provides a continuous flow of air from an inflatable object during both up and down stroke of the piston shaft.




Another object of the present invention is to provide an air pump that has both intake port and exhaust port that provide a continuous flow of air to and from the inflatable object during both up and down stroke of the piston.




Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.




To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described, an air pump comprises a first structure having a hollow interior and a piston slidably disposed in the housing to divide the hollow interior of the housing to first and second reservoirs. In the preferred embodiment, as the piston moves toward a first direction, such as upstroke, the first reservoir is compressed and as the piston moves toward a second direction, such as down stroke, the second reservoir is compressed. The air pump further comprises a second structure having gaseous communication with the first structure. The second structure has intake and exhaust chambers which are not in gaseous communication with each other. The intake chamber is in gaseous communication with an intake port. The exhaust chamber is in gaseous communication with an exhaust port. The air pump also includes first and second intake check valves and first and second exhaust check valves disposed in the air pump. The first intake check valve provides gaseous communication between the second reservoir and the intake chamber when the piston moves in the first direction. The second intake check valve provides gaseous communication between the first reservoir and the intake chamber when the piston moves in the second direction. Similarly, the first exhaust check valve provides gaseous communication between the second reservoir and the exhaust chamber when the piston moves in the second direction, and the second exhaust check valve provides gaseous communication between the first reservoir and the exhaust chamber when the piston moves in the first direction.




According to one aspect of the present invention, the first and second intake check valves are located in the second structure and are dedicated to the intake chamber. The first and second exhaust check valves are also located in the second structure and are dedicated to the exhaust chamber.




In the preferred embodiment, the first structure is a cylindrical housing fixedly attached to the second structure, which is a base, wherein the first and second intake check valves are disposed in the second reservoir of the housing. The first and second intake check valves and the first and second exhaust check valves are preferably co-planarly located on the second structure.




According to another aspect of the present invention, the air pump includes an intake transfer tube connected between the intake chamber and the first chamber with air flow being regulated by the second intake check valve. There is also an exhaust transfer tube connected between the exhaust chamber and the first chamber with air flow being regulated by the second exhaust check valve.




According to another aspect of the invention, a piston shaft is fixedly connected to the piston for biasing the piston between the first and second positions. The piston shaft is parallelly disposed with the intake and the exhaust transfer tubes.




According to another aspect of the present invention, a disk is fixedly attached to one end of the housing. The disk defines an intake conduit connected to the intake transfer tube and further defines an exhaust conduit connected to the exhaust transfer tube. The disk further defines at least one air passage which is in gaseous communication with the first reservoir of the first structure.




It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide a further explanation of the invention as claimed.











BRIEF DESCRIPTION OF THE DRAWINGS




The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.





FIG. 1

illustrates a perspective view of a preferred embodiment of the dual action air pump with a piston shaft in a retracted position;





FIG. 2

illustrates a perspective view of the preferred embodiment of the dual action air pump with the shaft piston in an extended position;





FIG. 3

illustrates an exploded view of the dual action air pump;





FIG. 4

illustrates a cross-sectional view of the dual action air pump showing internal components and air flow directions when the piston is moving in a up stroke;





FIG. 5

illustrates a cross-sectional view of the dual action air pump showing internal components and air flow directions when the piston is moving in a down stroke;





FIG. 6

illustrates a bottom planar view of the dual action air pump showing intake and exhaust check valves;





FIG. 7

illustrates a cross-sectional view of intake and exhaust check valves for a lower reservoir; and





FIG. 8

illustrates a cross-sectional view of intake and exhaust check valves for an upper reservoir.











DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS




With reference to the drawings, and in particular to

FIGS. 1-8

thereof, a dual action air pump


100


embodying the principles and concepts of the present invention will be described.





FIG. 1

illustrates a perspective view of a preferred embodiment of the dual action air pump


100


with a piston shaft


112


in a retracted position.

FIG. 2

illustrates a perspective view of the preferred embodiment of the air pump


100


with the piston shaft


112


in an extended position. Referring to

FIGS. 1 and 2

, the air pump


100


according to the present invention includes a cylindrically shaped hollow reservoir housing


102


, a base


104


connected to one end of the housing


102


, an intake port


106


and an exhaust or inflate port


108


which are located on the base


104


, an elongated piston shaft


112


extending along the longitudinal axis of the housing


102


, and a handle perpendicularly disposed with respect to the piston shaft


112


to assist pumping of the piston shaft


112


. The preferred embodiment of the present invention is directed to a dual action manually driven air pump


100


with a piston and two intake and two exhaust check values that respectively operate with one intake port


106


and one exhaust (or inflation) port


108


. These check valves, which are described below in detail, operate in tandem with each other during each pumping stroke, either up or down. In particular, during each pumping stroke, one intake check valve and one exhaust check valve are open with their counterparts closed, to provide continuous discharge of compressed air through the exhaust port


108


and also to provide continuous intake of air through the intake port


106


.





FIG. 3

illustrates an exploded view of the air pump


100


according to the preferred embodiment of the present invention. As described above, the housing


102


is cylindrically shaped and is divided into upper and lower reservoirs


206


and


208


, as shown in

FIG. 4

, by the placement of a piston


130


for concurrently receiving and compressing air. The length and the diameter of the housing


102


, which determines the volume of the reservoirs, may be varied depend on the application of the air pump


100


. The housing


102


is preferably made of rigid plastic, PVC, aluminum or other suitable materials known to one of ordinary skill in the art.




Referring to

FIG. 3

, the top opening end of the housing


102


is enclosed with a disk


150


having a plurality of air transport holes. The bottom opening end of the housing


102


is air tightly mounted to the base


104


. Preferably, the top surface of the base


104


has a circular groove


170


for receiving therein the housing


102


in an upright position. The housing


102


and the base


104


may be securely attached to each other using adhesives or other suitable material known to one of ordinary skill in the art.




In the preferred embodiment, the disk


150


is air tightly affixed to the top end of the housing, preferably using adhesives. Alternatively, the disk


150


may have external threads which are fixedly engaged with the matching inner threads of the housing


102


. The disk


150


preferably has a center hole


156


for slidably receiving therein the piston shaft


112


. The diameter of the center hole


156


is about the same as that of the piston shaft


112


to snuggly fit around the circumference of the piston shaft


112


. Aligned with and disposed at opposite ends of the center hole


156


are a plurality of air passages


152


and


154


which are in gaseous communication with the upper reservoir of the housing


102


. In the preferred embodiment, there are two air passages


152


and


154


defined by the disk


150


. Alternative, there may be one or more than two air passages. In addition to the air passages


152


and


154


, there are intake and exhaust conduits


158


and


160


which are in gaseous communication with transfer tubes


162


and


164


. In particular, the intake and exhaust conduits


158


and


160


are linearly aligned with the center hole


156


and are orthogonally positioned with respect to the air passages


152


and


154


.




Referring further to

FIG. 3

, the top end of the housing


102


has outer threads for receiving thereon a cover


120


which has matching inner threads. Once placed on the housing


102


, the cover


120


forms an air tight seal. The cover


120


has a piston shaft hole


124


which shares the same center axis as the cover


120


. The piston shaft hole


124


is surrounded by a rim


122


having an O-ring therein to provide substantially an air tight seal with the piston shaft


112


. The cover


120


also includes an input port


126


having a check valve biased to open only during a down stroke of the piston shaft


112


to fill the upper reservoir


206


.




Referring to

FIG. 3

, parallelly extending from the bottom surface of the disk


150


are intake transfer tube


162


and exhaust transfer tube


164


. Preferably, the intake transfer tube


162


, the exhaust transfer tube


164


and the piston shaft


112


are in co-planarly position with respect to each other. The intake and exhaust transfer tubes


162


and


164


are elongated cylinders of identical shape and form having a hollow interior for transferring air between chambers located in the base


104


. The intake and exhaust transfer tubes


162


and


164


extend along the length of the housing


102


and are in gaseous communication with the upper reservoir


206


, but are not in gaseous communication with the lower reservoir


208


of the housing


102


. The intake transfer tube


162


is fixedly connected and is dedicated to an intake transfer tube valve


172


. The exhaust transfer tube


164


is fixedly connected and is dedicated to an exhaust transfer tube valve


176


. As a result, the intake and exhaust transfer tubes


162


and


164


act as air conduits feeding and exhausting air to and from the upper reservoir


206


.




According to

FIG. 3

, the air pump


100


also includes an elongated piston shaft


112


which is connected to the handle


110


at one end and is connected to a piston


130


at the opposite end. The piston shaft


112


and the handle


110


form a T-shaped structure. The piston


130


has a generally circular construction and has a center hole for mounting therein the end of the piston shaft


112


. There are also two transfer tube through-holes


132


and


134


for slidably receiving therethrough the intake and the exhaust transfer tubes


164


and


162


, respectively. The through holes


132


and


134


are each configured to be slightly larger in diameter than that of the transfer tubes


164


and


162


and provide air tight seals around the transfer tubes


164


and


162


to separate the upper and lower reservoirs


206


and


208


. The through holes


132


and


134


are aligned with the intake and the exhaust conduits


158


and


160


so that the air transfer tubes


162


and


164


run co-planar and parallel to the piston shaft


112


.




Around the circumference of the piston


130


, there is provided a groove rail for receiving therein an O-ring


136


. The O-ring


136


in piston


130


rubs against the inner wall of the upper and the lower reservoirs


206


and


208


. The O-ring


136


provides an air tight seal between the piston


130


and the inner wall of the housing


102


to compress air in the upper reservoir


206


when the piston


130


is moved upward and in the lower reservoir


208


when the piston


130


is moved downward.




According to

FIG. 3

, the air pump


100


also includes the base


104


which is perpendicularly connected to the housing


102


for forming an air tight seal at the contact joint. A perspective view of the base


104


is shown in

FIG. 3

, and a bottom plan view of the base


104


is shown in FIG.


6


. Referring to

FIG. 3

, the base


104


includes intake valve


174


and exhaust valve


178


which are both dedicated to the lower reservoir


208


, and intake transfer tube valve


172


and exhaust transfer tube valve


176


which are both dedicated to the upper reservoir


206


. All four check valves, namely intake transfer tube valve


172


, intake valve


174


, exhaust transfer tube valve


176


and exhaust valve


178


, are located within the boundary defined by the lower opening of the housing


102


. In particular, the intake and the exhaust transfer tube valves


172


and


176


are located immediately below the corresponding intake and exhaust transfer tubes


162


and


164


, respectively. In other words, the intake transfer tube valve


172


is in gaseous communication with the intake transfer tube


162


. Similarly, the exhaust transfer tube valve


177


is in gaseous communication with the exhaust transfer tube


164


. In the preferred embodiment, all four check valves


172


,


174


,


176


and


178


are co-planarly located on the top of the base


104


.




The construction of check valves is well known in the art. For example, each check valve used in the present invention includes a circular flexible disk, preferably made of rubber, having a center projection for engaging a valve opening. The valve is biased in one direction to permit unidirectional air flow.




Referring to

FIG. 3

, the base


104


also includes an intake port


106


and an exhaust port


108


, which are in gaseous communication with an intake chamber


202


and an exhaust chamber


204


, respectively. The intake chamber


202


includes the two intake check valves


172


and


174


and has a single intake port


106


. The exhaust chamber


204


includes the two exhaust check valves


176


and


178


and has a single exhaust port


108


. In the preferred embodiment, the intake transfer tube valve


172


and the intake valve


174


are positioned on one side of the base


104


to share the intake chamber


202


shown in FIG.


6


. The exhaust transfer tube valve


176


and the exhaust valve


178


are positioned on the opposite side of the base


104


to share the exhaust chamber


204


.




The intake port


106


is used for receiving or deflating air from outside. When connected to an inflatable article, the intake port


106


will continuously intake air to deflate such article. The exhaust port


108


is used for inflating by force outputting the compressed air inside the housing


102


. The intake port


106


is in gaseous communication with the intake chamber


202


. The exhaust port


108


is in gaseous communication with the exhaust chamber


204


.




Referring to

FIG. 3

, there is provided a chamber cover


220


having a raised wall


222


in the shape of the chamber wall


210


and the dividing wall


212


. The raised wall


222


is two layered with a rubber sealing ring


224


in between. The chamber cover


220


is preferably attached to the bottom of the base


104


around the intake and the exhaust chambers


202


and


204


using fasteners such as screws, or other suitable method. When the chamber cover


220


is placed against the chambers


202


and


204


, the sealing ring


224


abuts against the top of the chamber wall


210


and the dividing wall


212


so that the chamber cover


220


maintains an air tight seal of the chambers


202


and


204


. Once the chamber cover


220


is placed, the bottom of the base


104


is enclosed with a similarly shaped base cover


230


.





FIG. 6

illustrates a bottom planar view of the air pump


100


, and particularly the base


104


, showing intake and exhaust check valve arrangement.

FIG. 7

illustrates a cross-sectional view of intake and exhaust valves for a lower reservoir


208


.

FIG. 8

illustrates a cross-sectional view of intake and exhaust valves for an upper reservoir


206


. Referring to

FIG. 6

, the intake and the exhaust chambers


202


and


204


are defined by a generally rectangular chamber wall


210


. The intake and the exhaust chambers


202


and


204


are divided by a dividing wall


212


which is of substantially the same height as the wall


210


.




Referring to

FIGS. 6 and 7

, there are shown the exhaust valve


178


which is in gaseous communication with the exhaust chamber


204


, and the intake valve


174


which is in gaseous communication with the intake chamber


202


. Referring to

FIGS. 6 and 8

, there are shown the exhaust transfer tube valve


176


which is in gaseous communication with the exhaust chamber


204


, and the intake transfer tube valve


172


which is in gaseous communication with the intake chamber


202


. According to the preferred embodiment of the present invention, the intake transfer tube valve


172


is installed on an intake platform


180


and the exhaust transfer tube valve


182


is installed on an exhaust platform


182


. On the top surface of the base


104


surrounding the intake and the exhaust transfer tube valves


172


and


176


, there are circular rims


184


and


186


for receiving therein the intake and the exhaust transfer tubes


162


and


164


, respectively. The circular rims


184


and


186


have a diameter which is slightly larger than that of the tubes


162


,


164


and are respectively attached to each other using adhesives to provide an air tight seal from the lower reservoir


208


.




The operation of the air pump


100


according to the preferred embodiment of the present invention will now be described in reference to

FIGS. 4 and 5

.

FIG. 4

illustrates a cross-sectional view of the air pump


100


showing internal components and air flow directions when the piston is moving upward. As the piston


130


travels up and down, the upper and the lower reservoirs


206


and


208


compress or expand as shown in

FIGS. 4 and 5

, respectively. The intake port


106


and the exhaust port


108


are always unrestricted and open and feed or exhaust the intake chamber


202


and the exhaust chamber


204


.




In an upstroke, the air in the upper reservoir


206


is compressed and is exhausted through the exhaust port


108


as the lower reservoir


208


is filled up with air received from the intake port


106


. In particular, the intake valve


174


opens and feeds lower reservoir


208


of the housing


102


. Concurrently, the exhaust valve


178


is kept closed from back pressure in the exhaust chamber


204


, while the lower reservoir


208


is filled with air received from the intake port


106


of the intake chamber


202


through the intake valve


174


. The compressed air in the upper reservoir


206


exits through the air passage


154


, enters the exhaust conduit


160


, moves down the exhaust transfer tube


164


into the exhaust chamber


204


, and exits through the exhaust port


108


. The following is the status of various valves used in the air pump


100


during the upstroke.















UPSTROKE SUMMARY
























Intake valve 174




Opens to feed lower reservoir 208






Intake transfer tube valve 172




Closes






Exhaust valve 178




Closes






Exhaust transfer tube valve 176




Opens to feed exhaust chamber 204















FIG. 5

illustrates a cross-sectional view of the air pump


100


showing internal components and air flow directions when the piston


130


is in a down stroke. In a down stroke, the lower reservoir


208


is compressed and the air therein exhausts through the exhaust port


108


while the upper reservoir


206


is filled up with air received from the intake port


106


. During a down stroke, the intake valve


174


closes and the exhaust valve


178


opens allowing the compressed air in the lower reservoir


208


to escape or exhaust into the exhaust chamber


204


. The compressed air then exits through the exhaust port


108


. The intake transfer tube valve


172


for the upper reservoir


206


opens with air travelling through the intake port


106


into the intake chamber


202


, through the intake transfer tube valve


172


, and up the intake transfer tube


162


. The air then exits through the intake conduit


158


and travels into the upper reservoir


206


through the air passage


154


. During a down stroke, the exhaust transfer tube valve


176


is kept closed from the back pressure in the exhaust chamber


204


. The following is the status of various valves used in the air pump


100


during the down stroke.















DOWN STROKE SUMMARY
























Intake valve 174




Closes






Intake transfer tube valve 172




Opens to feed upper reservoir 206






Exhaust valve 178




Opens to feed exhaust chamber 204






Exhaust transfer tube valve 176




Closes














As described above, on the reversing of the stroke, the check valves that were previously open now become closed and those that were closed now become open. This results in a continuous flow of air, to or from the inflatable object, depending upon whether the air hose is connected to the intake or to the exhaust port.




Although the air pump


100


described above is directed to a manually operated pump, the gist of the present invention may also be applied to an electric-type pump using the same check valve configuration.




It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.



Claims
  • 1. An air pump comprising:a first structure having a hollow interior; a piston slidably disposed in the housing to divide the hollow interior of the housing to first and second reservoirs, wherein as the piston moves toward a first direction, the first reservoir is compressed and as the piston moves toward a second direction, the second reservoir is compressed; a second structure having gaseous communication with the first structure, the second structure having intake and exhaust chambers which are not in gaseous communication with each other, the intake chamber being in gaseous communication with an intake port, the exhaust chamber being in gaseous communication with an exhaust port; and first and second intake check valves disposed in the air pump, wherein the first intake check valve provides gaseous communication between the second reservoir and the intake chamber when the piston moves in the first direction, and the second intake check valve provides gaseous communication between the first reservoir and the intake chamber when the piston moves in the second direction.
  • 2. The air pump of claim 1, further comprising:first and second exhaust check valves disposed in the air pump, wherein the first exhaust check valve provides gaseous communication between the second reservoir and the exhaust chamber when the piston moves in the second direction, and the second exhaust check valve provides gaseous communication between the first reservoir and the exhaust chamber when the piston moves in the first direction.
  • 3. The air pump of claim 2, wherein the first and second exhaust check valves are located in the second structure and are dedicated to the exhaust chamber.
  • 4. The air pump of claim 2, wherein the first structure is a cylindrical housing fixedly attached to the second structure, wherein the first and second exhaust check valves are disposed in the second reservoir of the housing.
  • 5. The air pump of claim 2, further comprising an exhaust transfer tube connected between the exhaust chamber and the first chamber with air flow being regulated by the second exhaust check valve.
  • 6. The air pump of claim 2, further comprising a piston shaft fixedly connected to the piston for positioning the piston between the first and second positions.
  • 7. The air pump of claim 2, wherein the first and second intake check valves and the first and second exhaust check valves are co-planarly located on the second structure.
  • 8. The air pump of claim 1, wherein the first and second intake check valves are located in the second structure and are dedicated to the intake chamber.
  • 9. The air pump of claim 1, wherein the first structure is a cylindrical housing fixedly attached to the second structure, wherein the first and second intake check valves are disposed in the second reservoir of the housing.
  • 10. The air pump of claim 1, further comprising an intake transfer tube connected between the intake chamber and the first chamber with air flow being regulated by the second intake check valve.
  • 11. The air pump of claim 10, further comprising an exhaust transfer tube connected between the exhaust chamber and the first chamber with air flow being regulated by the second exhaust check valve.
  • 12. The air pump of claim 11, further comprising a piston shaft fixedly connected to the piston for positioning the piston between the first and second positions, wherein the piston shaft is parallelly disposed with the intake and the exhaust transfer tubes.
  • 13. The air pump of claim 11, firer comprising a disk fixedly attached to one end of the housing, wherein the disk defines an intake conduit connected to the intake transfer tube and further defines an exhaust conduit connected to the exhaust transfer tube.
  • 14. The air pump of claim 13, wherein the disk further defines at least one air passage which is in gaseous communication with the first reservoir of the first structure.
  • 15. The air pump of claim 1, further comprising a piston shaft fixedly connected to the piston for positioning the piston between the first and second positions.
  • 16. An air pump comprising:a housing having a hollow interior and first and second ends, the second end of the housing being closed with a cover defining a through hole; a piston shaft slidably disposed through the through hole of the cover, the piston shaft having an end with a piston slidably disposed in the housing to divide the hollow interior of the housing to first and second reservoirs, wherein as the piston moves toward a first direction, the first reservoir is compressed and as the piston moves toward a second direction, the second reservoir is compressed; a seal disposed around the piston, the seal having an outer periphery contacting an inner periphery of the housing; a base having gaseous communication with the housing and fixedly connected to the first end of the housing, the base having intake and exhaust chambers which are not in gaseous communication with each other, the intake chamber being in gaseous communication with an intake port, the exhaust chamber being in gaseous communication with an exhaust port; first and second intake check valves disposed in the air pump, wherein the first intake check valve provides gaseous communication between the second reservoir and the intake chamber when the piston moves in the first direction, and the second intake check valve provides gaseous communication between the first reservoir and the intake chamber when the piston moves in the second direction; first and second exhaust check valves disposed in the air pump, wherein the first exhaust check valve provides gaseous communication between the second reservoir and the exhaust chamber when the piston moves in the second direction, and the second exhaust check valve provides gaseous communication between the first reservoir and the exhaust chamber when the piston moves in the first direction; an intake transfer tube connected between the intake chamber and the first chamber with air flow being regulated by the second intake check valve; and an exhaust transfer tube connected between the exhaust chamber and the first chamber with air flow being regulated by the second exhaust check valve.
  • 17. The air pump of claim 16, wherein the first and second intake check valves are located in the second structure and are dedicated to the intake chamber.
  • 18. The air pump of claim 17, wherein the first and second exhaust check valves are located in the second structure and are dedicated to the exhaust chamber.
  • 19. The air pump of claim 18, wherein the housing is fixedly attached to the second structure, wherein the first and second exhaust check valves are disposed in the second reservoir of the housing.
  • 20. The air pump of claim 16, wherein the housing is fixedly attached to the second structure, wherein the first and second intake check valves are disposed in the second reservoir of the housing.
  • 21. The air pump of claim 16, wherein the first and second intake check valves and the first and second exhaust check valves are co-planarly located on the base.
  • 22. The air pump of claim 16, further comprising a disk fixedly attached to the second end of the housing, wherein the disk defines an intake conduit connected to the intake transfer tube and defines an exhaust conduit connected to the exhaust transfer tube.
  • 23. The air pump of claim 22, wherein the disk further defines at least one air passage which is in gaseous communication with the first reservoir of the housing.
  • 24. An air pump comprising:a cylindrical housing having a hollow interior; a piston slidably disposed in the housing to divide the hollow interior of the housing to first and second reservoirs, wherein as the piston moves toward a first direction, the first reservoir is compressed and as the piston moves toward a second direction, the second reservoir is compressed; a second structure having gaseous communication with the first structure, the second structure having intake and exhaust chambers which are not in gaseous communication with each other, the intake chamber being in gaseous communication with an intake port, the exhaust chamber being in gaseous communication with an exhaust port; first and second intake valve means, wherein the first intake check valve means is provided for controlling air flow between the second reservoir and the intake chamber when the piston moves in the first direction, and the second intake check valve means is provided for controlling air flow between the first reservoir and the intake chamber when the piston moves in the second direction; and first and second exhaust check valve means, wherein the first exhaust check valve means is provided for controlling air flow between the second reservoir and the exhaust chamber when the piston moves in the second direction, and the second exhaust check valve means is provided for controlling air flow between the first reservoir and the exhaust chamber when the piston moves in the first direction.
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6027319 Winefordner et al. Feb 2000
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