Information
-
Patent Grant
-
6299420
-
Patent Number
6,299,420
-
Date Filed
Thursday, April 6, 200024 years ago
-
Date Issued
Tuesday, October 9, 200123 years ago
-
Inventors
-
Original Assignees
-
Examiners
- Walberg; Teresa
- Patel; Vinod D.
Agents
- Lewis, D'Amato, Brisbois & Bisgaard LLP
-
CPC
-
US Classifications
Field of Search
US
- 417 527
- 417 526
- 417 440
- 417 467
- 417 511
- 417 512
-
International Classifications
-
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.
US Referenced Citations (11)