US20070237662A1

US20070237662A1 - Compressor having a piston performing simultaneous functions

Info

Publication number: US20070237662A1
Application number: US11/586,038
Authority: US
Inventors: Juan Kippes
Original assignee: Individual
Current assignee: Individual
Priority date: 2005-10-25
Filing date: 2006-10-24
Publication date: 2007-10-11
Also published as: AR054316A1

Abstract

AN COMPRESSOR HAVING A PISTON PERFORMING SIMULTANEOUS FUNCTIONS, which consists of a piston with a top part having a diameter smaller than that of the bottom part. Over the piston, in a reservoir (which has an outlet for compressed air) over the piston cylinder, is located a valve that covers the whole of the top opening of the cylinder. The bottom reservoir, where a crankshaft is located, is connected to the top part of the piston cylinder through passages that allow air to flow from this bottom chamber into the top part of the cylinder. The bottom reservoir has intake valves that open as the piston moves up and close as the piston moves down.

Description

TECHNICAL FIELD OF THE INVENTION

The present invention relates to a COMPRESSOR HAVING A PISTON PERFORMING SIMULTANEOUS FUNCTIONS, its assembly consisting of a 2-stage compressor mechanism, with a piston that performs several simultaneous functions utilizing each stroke of the piston, so that it performs the functions of intake and compression at the same time, both in its ascent and in its descent, allowing the prior compression of the air to be compressed.

PRIOR ART AND PROBLEMS TO BE SOLVED

A large number of embodiments and systems are currently known to be used as compressors using ordinary cylindrical-section pistons, ports, and/or valves of different types.
The present invention is totally novel in that one flat valve is directly used instead of the cylinder head, reducing the total weight and the number of components of the device. This results in the smaller size of the device, and its simplicity reduces the likelihood of failure, and, should any failure occur, repairing and accessing the different components of the devise are easier. Additionally, the compression ratio is higher due to the fact that the total intake volume is higher than the volume of the top part of the piston cylinder, where compression occurs. It should be borne in mind that the intake surface and space (bottom area of the piston) are larger than the compression surface and space (top area of the piston, inside the cylinder), especially taking into account that compression, which occurs in this compression area, is applied to the previously compressed air from the bottom part of the piston cylinder and the bottom chamber (where the crankshaft is located). Each stroke of the piston is utilized efficiently because, as the piston moves up, it closes the ports (passages), compresses the air in the top and bottom parts of the cylinder, draws air from outside into the combustion chamber under the piston, and, finally, forces the compressed air in the bottom part of the cylinder into the bottom chamber and pushes the flat valve, opening the top opening of the cylinder. As the piston moves down, it allows compressed air below itself into the top part of the cylinder through a valve in the piston head, further compresses the air below the piston—thus compressing the air above the piston—, closes the intake valves in the bottom chamber, draws allows air from outside into the bottom part of the cylinder (opening the corresponding valves by creating a vacuum effect in this part), and, finally, forces more compressed air through the ports into the top part of the cylinder.
Considering all the foregoing, this invention is important.

SUMMARY OF THE INVENTION

This invention, titled COMPRESSOR HAVING A PISTON PERFORMING SIMULTANEOUS FUNCTIONS, relates to an assembly consisting of: a mechanism with a piston having an inverted T-shaped longitudinal section, since the diameter of its bottom part is larger than that of the top part. Each part has its corresponding rings and oil scraper rings, which are conventional, widely known, and in the public domain. This piston has the same characteristics as a conventional piston, except for its shape as described above, and is moved through a connecting rod by the rotation of a crankshaft (which is located in a bottom chamber—usually called “crankcase”—located directly under the piston cylinder). This crankshaft imparts an up-and-down motion to the piston inside the cylinder enclosing the piston, which enables the piston to move freely inside the cylinder from top to bottom. This piston cylinder has all the conventional characteristics of any cylinder, except for its shape, which fits that of the piston. The complete movement of a piston from one end to the other of the cylinder is called “stroke” or “piston travel.” With each rotation of the crankshaft, the piston has completed two strokes, one up and one down. Considering that a cycle is a series of occurrences that repeats or is repeated in one and the same order, this is a compressor with a two-stroke cycle. It should be taken into account that all the components mentioned herein (piston, cylinder, crankshaft, connecting rod, and crankcase) are widely known and used, both in piston compressors and in engines; therefore, no description is necessary.
As mentioned above, unlike other pistons, the diameter of the top part of the piston in this compressor is smaller than that of the bottom part of the piston; the length of each part will depend on the expected performance of the compressor, according to the reasonable ratios allowed by the interrelation of the components and their possible dimensions. Therefore, the diameter of the bottom part of the cylinder, in which the piston is housed and slides, is also larger than that of the top part of the cylinder, the length of each part of the cylinder depending on the length of each part of the piston. Over the piston and in a top chamber, which is directly over the piston cylinder, is located a flat valve that covers the whole of the top opening of the cylinder and rests on the top outer edge of the piston cylinder, thus acting as a cylinder head. (It should be taken into account that the cylinder surfaces as well as the bottom surface of the abovementioned valve and that of the piston skirt are mirror-polished.) The flat valve stem, which moves up and down, slides in a guide, which keeps it from sliding other than lengthwise. There is a gap in the middle part of the valve stem guide that house spring pushing the flat valve down. This spring is enclosed in a gap or chamber, and actuated by a retainer attached to the flat valve stem at some distance from the bottom end of the stem, thus allowing the proper operation of the spring, forcing the valve down and closing the top opening of the piston cylinder. The force of the spring is to be selected according to the expected initial flat-valve opening pressure because this pressure has to withstand the strength of the spring. When the spring is in operation, the pressure required to open the flat valve will depend on the pressure existing in the top chamber. The bottom chamber, which houses the crankshaft, and the top part of the piston cylinder are connected by one or more passages, or ports, which allow air to flow freely, from the bottom chamber into the top part of the cylinder. Two semicircular flat metal valves are attached to the horizontal flat surface of the piston cylinder, which connects the bottom part of the cylinder, having a larger diameter, to the top part of the cylinder, having a smaller diameter. These valves are attached by one end only; this allows the free movement of the other end, which is the one that acts as a valve by allowing or preventing the passage of outside air, depending on the difference between the pressures existing in the both ends of the each side (top and bottom) of the valves. (This type of valve is widely known and used in some compressors and engines.) Two rectangular valves, operating in a fashion similar to that of the abovementioned valves, are located on the top flat surface of the bottom chamber, where the crankshaft is located. These rectangular valves will either allow or not allow the entrance of outside air.
The bottom of the top part of the piston has two rectangular recesses. These recesses are parallel to the longitudinal axis of the piston and opposite each other. Thus when the piston reaches the top dead center, the recesses will face the inlets, which are located in the top part of the piston cylinder, of the passages, or ports, which connect the top part of the piston cylinder to the bottom chamber, where the crankshaft is located. This causes the air compressed by the travel of the bottom part of the piston to flow through the recesses to the passages and into the bottom chamber. Therefore, when the piston is at that point, and because of their rectangular shape and curved bottoms, the recesses connect the inlet of the passages to the chamber in which the bottom part of the piston compresses the air previously allowed through the abovementioned semicircular valves. On the piston head is attached a circular valve that forms part of the top surface of the piston. This valve is actuated by pressure difference because, as the piston moves up, the pressure in the top part of the cylinder pushes the valve down, thus causing the valve to tightly seal the top surface of the piston, whereas, as the piston moves down, it creates a vacuum in the top part of the cylinder; this, combined with the pressure of the air below the piston, causes the valve to open, allowing the air from the bottom part of the cylinder into the top part of the cylinder, thus preventing the vacuum created above the piston from applying an opposite force to the piston movement.
The whole assembly operates as follows: The force of the crankshaft (which is moved by a motor) acting on the connecting rod causes the piston to move down, closing the top opening in the piston cylinder via the flat valve, and initially creating a vacuum effect in the top part of the cylinder. This, combined with the downward piston movement compressing the air below the piston—with such compression closing the valves that allow outside air into the bottom chamber—, increases the pressure in the bottom part of the cylinder, causing the valve at the center of the surface of the piston to open, allowing air into the top part of the cylinder and preventing a vacuum effect that would apply an opposite force to the downward piston movement thus preventing a strain on the crankshaft motor and increasing the subsequent compression in the top part of the cylinder.) This valve remains open until the pressure in the top part of the cylinder is higher than that in the bottom part of the cylinder. The downward piston movement creates a vacuum effect in the bottom part of the cylinder (above the bottom part of the piston), causing the immediate opening of the semicircular intake valves, thus drawing air in from outside. During downward piston movement—almost at the end of the piston travel—, the piston opens the outlets of the passages that connect the top part of the cylinder to the bottom chamber, and some air compressed below the piston flows into the top part of the cylinder, thus balancing the pressure between both ends of the passage, which will be higher than atmospheric pressure.
Afterwards, as the piston begins to move down, it closes the outlets of the passages that connect the top part of the cylinder to the bottom chamber. Due to pressure difference, this causes the intake valves of the bottom chamber to open, drawing air in from outside, while the piston compresses the air that entered the bottom part of the cylinder during the downward stroke of the piston, closing the intake valves of this part by pressure. The piston compresses the previously compressed air located in the top part of the cylinder, tightly closes the valve that is at the top of the piston and that forms part of its top surface. As mentioned above, during its upward stroke, the piston compresses the air located in the top part of the cylinder until, as the piston is very near the flat valve that closes the top opening of the cylinder, the pressure causes the valve to open. As the piston moves further up and the flat valve begins to move down, due to the exhaust of the compressed air between them, a shock-absorbing effect (like a deflating air cushion) is created which allows both components (piston and valve) to make gentle contact with each other, they becoming such an integral assembly that no significant amount of air will remain between them. As the flat valve makes contact with the piston, the top ends of both rectangular recesses in the skirt of the top part of the piston will face the outlet of the passages that connect the top part of the cylinder to the bottom chamber, while the bottom ends of the recesses will continue to face the bottom part of the cylinder; therefore, these recesses act as passages that allow the air compressed in the bottom part of the cylinder into the bottom chamber, and, thus, stop applying an opposite force to the upward piston movement and push the piston from the bottom chamber due to an increase in the air pressure, which closes the intake valves of the bottom chamber.
The arrangement and flat shape of the top valve allow it to expand (due to the temperature reached in the compression stroke) and with no risk of the valve getting caught.
The compressed air released through the openings in the flat valve exits the top chamber through a passage in the chamber into, for example, an air receiver. Afterwards, the piston begins to move down and, therefore, the cycle starts again. Both the cooling, air-filter, and lubrication system and the intake-valve system of this assembly are conventionally used in compressors, and, as their operation is in the public domain, no description is necessary herein.

BRIEF DESCRIPTION OF THE DRAWINGS

Several schematic drawings of a preferred embodiment of the invention, which should be taken as an example without limitation, are annexed hereto so that the invention may be better understood, where:
FIG. 1 is a view in longitudinal section parallel to the axis of the crankshaft, showing the piston at a specific point on its travel.
FIG. 2 is a view in longitudinal section perpendicular to the axis of the crankshaft, showing the piston at a specific point on its travel.
FIG. 3 is a view showing the details of the flat valve retainer that serves as a stop for the spring pushing the valve down.
FIG. 4 is a view showing the closed arrangement of the valve operating in the top part of the piston.
FIG. 5 is a view showing the open arrangement of the valve operating in the top part of the piston.
FIG. 6 is a perspective view of the semicircular valves in the bottom part of the piston, detached form the cylinder.
FIG. 7 is a bottom view of the arrangement of the semicircular valves in the bottom part of the piston.
FIGS. 8-15 are views in longitudinal section parallel to the axis of the crankshaft and longitudinal section perpendicular to the axis of the crankshaft, showing the piston at specific points on its travel, simply to better describe the operation of the assembly, where:
FIGS. 8 and 9 are views in longitudinal section parallel to the axis of the crankshaft and longitudinal section perpendicular to the axis of the crankshaft, respectively, showing the piston at a specific point on its travel, which will be taken as the initial point of the piston stroke, simply to better describe the operation of the assembly.
FIGS. 10 and 11 are views in longitudinal section parallel to the axis of the crankshaft and longitudinal section perpendicular to the axis of the crankshaft, respectively, showing the piston at a subsequent point, with respect to the above figures, on its travel.
FIGS. 12 and 13 are views in longitudinal section parallel to the axis of the crankshaft and longitudinal section perpendicular to the axis of the crankshaft, respectively, showing the piston at a subsequent point, with respect to the above figures, on its travel.
FIGS. 14 and 15 are views in longitudinal section parallel to the axis of the crankshaft and longitudinal section perpendicular to the axis of the crankshaft, respectively, showing the piston at a subsequent point, with respect to the above figures, on its travel.

DETAILED DESCRIPTION OF THE INVENTION

In order for the present invention to be clearly understood and the main idea of the invention to be easily implemented, a precise description of a preferred embodiment of the invention is provided below by reference to the schematic drawings annexed hereto, with all reference numbers indicating the same or corresponding items, all of which to be taken as an example without limitation, where:
FIGS. 1 and 2 are views in longitudinal section parallel to the axis of the crankshaft and longitudinal section perpendicular to the axis of the crankshaft, respectively, showing the piston at one and the same point on its travel, simply to better describe the components of the assembly. These figures show that the mechanism assembly consists of a piston (1) having a top part (1A) with a smaller diameter than that of the bottom part (1B), so the piston has an inverted T-shaped longitudinal section. Therefore, the diameter of the bottom side of the piston is larger than that of the top side. The piston moved by the rotation of a crankshaft (2), which is located in a bottom chamber (3). This bottom chamber is located directly under the piston cylinder (4). The crankshaft moves a connecting rod (5), so that the crankshaft, combined with the connecting rod (5), imparts an up-and-down motion to the piston (1)—this mechanism for moving the piston is conventional; therefore, it is in the public domain. As mentioned above, unlike other pistons, the diameter of the top part (1A) of the piston in this device is smaller than that of the bottom part (1B) of the piston; therefore, the diameter of the top part (1A) of the piston cylinder (4), or chamber in which the piston is housed and slides, is also smaller than that of the bottom part (1B) of the cylinder, the length of each part of the cylinder depending on the length of each part of the piston (1).
Over the piston (1) and in a top chamber (6), which is also directly over the piston cylinder (4A), is located a flat valve (7) that covers the whole of the opening in the top part of the cylinder (4A), thus acting as a movable cylinder head. The stem (7A) of the flat valve (7), which moves up and down, slides in two guides (8 and 8A), which keep it from sliding other than lengthwise. There is a spring (9) between the guides that pushes the flat valve (7) down. This spring is enclosed in a chamber (10), and applies pressure down on a retainer (11) attached to the flat valve stem (7A), at some distance from the top end of the flat valve, thus allowing the proper operation and actuation of the spring (9) in conjunction with the flat valve (7), causing the valve to close the top outlet of the top part of the piston cylinder (4A).
The bottom reservoir (3), where the crankshaft (2) is located, is connected to the top part of the cylinder (4A) through one or two passages (12 and 12A) that allow air to flow freely, from this bottom chamber (3) into the top part of the cylinder (4A), as long as the top part of the piston (1A) does not block the outlets (12B and 12C) located in the top part of the cylinder (4A).
There are two air inlets (13 and 13A) in the bottom reservoir (3), where the crankshaft (2) is located. These inlets are adjusted by valves (14 and 14A) that allow the entrance of outside air through passages (18 and 18A) as the piston (1) begins to move up creating a vacuum effect, which reduces the pressure in the bottom chamber, so that the outside atmospheric pressure will be higher, causing these valves to open due to pressure difference. These valves open when the piston reaches the top dead center, because the pressure in the bottom chamber increases due to the fact that, as both recesses (19 and 19A) in the piston skirt (at the bottom of the top part of the piston) are opposite each other, the compressed air located in the bottom part of the cylinder flows into the bottom chamber, as described above. And there is an outlet (15) in the top reservoir (6) to, for example, an air receiver.
There is a valve (16) that forms part of the top surface of the piston. This valve (shown in its open position) tightly closes a central circular opening when the pressure above the valve is higher than the pressure below the valve; in the opposite case, the valve will open. The valve will close due to a spring that acts on a retainer located at the end of the valve stem. When the valve opens, the air located in the bottom chamber will flow through the piston and the valve-opening passage into the chamber in the top part of the piston cylinder.
Two semicircular flat metal valves (17 and 17A) are attached to the horizontal flat surface of the piston cylinder, which connects the bottom part of the cylinder, having a larger diameter, to the top part of the cylinder, having a smaller diameter. These valves are attached by one end only; this allows the free movement of the other end, which is the one that acts as a valve.
Both the bottom and top parts of the piston have each their corresponding rings and oil-scraper rings (20 and 21A), which are conventional rings and allow the proper operation of the piston preventing it from getting caught.
FIG. 3 is a magnified view of the joint between the retainer (I 1) and the “valve sprig retainer lock” (11A), a part of the flat valve stem (7A), and the spring (9). This conventional thrust system is the same as the one used by the piston-head valve. FIGS. 4 and 5 are magnified views in longitudinal section through the middle of the piston, showing the piston—head valve in the closed (FIG. 4) and open (FIG. 5) positions. These figures clearly show the valve (16), the valve stem (16A), the spring (21) pushing the valve (16) down, and the area of the piston head (4A) that includes the valve (16).
FIG. 5 shows the air flow, represented by flow direction arrows, with the valve (16) in the open position.
FIG. 6 is a bottom perspective view of the semicircular valves (17 and 17A) in the bottom part of the piston, detached from the cylinder, showing the holes for setscrews (22, 22A, 22B, and 22C).
FIG. 7 is a bottom plan view in cross section through the bottom part of the piston cylinder (4B), showing the arrangement of the semicircular valves (17 and 17A), which are located in the bottom part of the cylinder. This figure shows the air intake passages (18 and 18A) at the ends of and behind the valves, as well as the holes for setscrews (22, 22A, 22B, and 22C), the bottom part of the cylinder (4B), and the top part of the cylinder (4A).
FIGS. 8-15 are views in longitudinal section parallel to the axis of the crankshaft and longitudinal section perpendicular to the axis of the crankshaft, showing the piston at specific points on its travel, simply to better describe the operation of the assembly. These figures only list again those components required for a simpler interpretation of the figures. The operation of the assembly is as follows:
FIGS. 8 and 9 show the piston at a specific point on its travel, which will be taken as the initial point of the piston stroke. The force of the crankshaft (which can moved by any motor with the required power) acting on the connecting rod causes the piston to move down, closing the top opening in the piston cylinder via the flat valve (7), and initially creating a vacuum effect in the top part of the cylinder (4A). This, combined with the downward piston movement compressing the air below the piston—with such compression closing the valves (14 and 14A) that allow air from outside through the passages (13 and 13A) into the bottom chamber—, increases the pressure in the bottom part of the cylinder, causing the valve (16) at the center of the piston top surface to open, allowing air into the top part of the cylinder (4A), which prevents a vacuum effect that would apply an opposite force to the downward piston movement (thus preventing a strain on the crankshaft motor and subsequently increasing the compression in the top part of the cylinder.) This valve (16) remains open until the pressure in the top part of the cylinder is higher than that in the bottom part of the cylinder. The downward piston movement creates a vacuum effect in the chamber in bottom part of the cylinder (4B) (above the bottom part (1B) of the piston), causing the immediate opening of the semicircular valves (17 and 17A), and drawing air in from outside through the passages (18 and 18A). During downward piston movement—almost at the end of the piston travel (see FIGS. 10 and 11)—, the piston opens the outlets of the passages (12B and 12C) that connect the top part of the cylinder to the bottom chamber, and some air compressed below the piston flows into the top part of the cylinder (4A), thus balancing the pressure between both ends of the passage, which will be higher than atmospheric pressure.
As the piston begins to move down (see FIGS. 12 and 13), it closes the outlets of the passages that connect the top part of the cylinder to the bottom chamber. Due to pressure difference, this causes the intake valves (14 and 14A) of the bottom chamber to open, drawing air in from outside, while the piston compresses the air that entered the bottom part of the cylinder (4B), closing the intake valves of this part by pressure. The piston compresses the previously compressed air located in the top part of the cylinder, tightly closes the valve that is at the top of the piston (piston head) and that forms part of its top surface. As mentioned above, during its upward stroke, the piston compresses the air located in the top part of the cylinder until (see FIGS. 14 and 15), as the piston is very near the flat valve that closes the top opening of the cylinder, the pressure causes the valve to open. As the piston moves further up and the flat valve begins to move down, due to the exhaust of the air between them, an air shock-absorbing effect is created which allows both components (piston and flat valve) to make gentle contact with each other, to the extent that no significant amount of air will remain between them. As the flat valve makes contact with the piston, the top ends of both rectangular recesses (19 and 19A) in the skirt of the top part of the piston will face the outlet of the passages that connect the top part of the cylinder to the bottom chamber, while the bottom ends of the recesses will continue to face the bottom part of the cylinder; therefore, these recesses act as passages that allow the air compressed in the bottom part of the cylinder into the bottom chamber, and, thus, stop applying an opposite force to the upward piston movement and push the piston from the bottom chamber due to an increase in the air pressure, which closes the intake valves of the bottom chamber.
The arrangement and flat shape of the top valve allow it to expand (due to the temperature reached in the compression stroke) and with no risk of the valve getting caught.
The compressed air released through the openings in the flat valve exits the top chamber through a passage in the chamber for such purpose.
Afterwards, the piston begins to move down and, therefore, the cycle starts again. Both the cooling, air-filter, and lubrication system and the intake-valve system of this assembly are conventionally used in compressors, and, as their operation is in the public domain, no description is necessary herein.
This invention may reasonably be implemented incorporating modifications to its construction, materials, and form, as long as this is done without departure from the fundamental principles clearly specified in the following claims:

Claims

1. (canceled)

2. A compressor, comprising:

a piston cylinder;

an inverted T-shaped piston at least partially disposed in said piston cylinder, wherein said piston has a top part with a top surface and a bottom part with a bottom surface, wherein said top part is forward of said bottom part during an up stroke of said piston, and wherein said bottom part is forward of said top part during a down stroke of said piston, wherein said bottom surface has a larger area than said top surface, wherein said piston cylinder and said piston at least partially define a top part of cylinder and a bottom part of cylinder at least at one point during travel of said piston, wherein said bottom surface of said bottom part at least partially defines a bottom chamber; and

a valve carried by said piston and having an open position to allow air to flow therethrough, wherein said valve has a closed position to prevent air from flowing therethrough, and wherein in said closed position of said valve an upper surface of said valve aligns with said top surface of said top part of said piston to form a flat surface.

3. The compressor as set forth in claim 2, further comprising a flat valve, wherein said flat valve and said top surface of said top part of said piston at least partially define said top part of cylinder when spaced from one another, and wherein said flat valve and said flat surface formed during alignment of said valve with said top surface of said top part of said piston contact one another at least at one point during travel of said piston.

4. The compressor as set forth in claim 3, wherein at least at some point during an up stroke of said piston air pressure in said top part of cylinder increases in order to open said flat valve to subsequently cause air in said top part of cylinder to be released across said flat valve and out of an outlet, and wherein subsequent to releasing air from said top part of cylinder across said flat valve and out of said outlet said flat valve and said flat surface formed during alignment of said valve with said top surface of said top part of said piston contact one another.

5. The compressor as set forth in claim 2, wherein at least at some point during a down stroke of said piston said bottom surface of said bottom part of said piston compresses air in said bottom chamber, and further comprising a bottom part of cylinder valve that is open at least at some point during a down stroke of said piston to allow air to enter said bottom part of cylinder.

6. The compressor as set forth in claim 2, wherein said valve is in said open position at least at some point during a down stroke of said piston to allow air in said bottom chamber to flow through said piston and out of said valve and into said top part of cylinder.

7. The compressor as set forth in claim 2, wherein at least one passage external to said piston is present between said bottom chamber and said top part of cylinder, and wherein said top part of said piston blocks an opening of said passage to prevent air from traveling therethrough at least at some point during a down stroke of said piston, and wherein said top part of said piston clears said opening of said passage to allow air flow from said bottom chamber to said top part of cylinder at least at some point during a down stroke of said piston.

8. The compressor as set forth in claim 2, wherein at least at some point during an up stroke of said piston air is compressed in said top part of cylinder and in said bottom part of cylinder by said piston, and further comprising a bottom chamber valve that is open at least at some point during an up stroke of said piston to allow air to enter said bottom chamber.

9. The compressor as set forth in claim 2, wherein said piston defines at least one rectangular recess, and wherein at least at some point during the travel of said piston air is transferred from said bottom part of cylinder through said rectangular recess and through a passageway external to said piston into said bottom chamber.

10. A compressor, comprising:

a piston cylinder;

an inverted T-shaped piston at least partially disposed in said piston cylinder, wherein said piston has a top part and a bottom part, wherein said top part is forward of said bottom part during an up stroke of said piston, and wherein said bottom part is forward of said top part during a down stroke of said piston, wherein said piston cylinder and said piston at least partially define a top part of cylinder and a bottom part of cylinder at least at one point during travel of said piston, wherein said bottom part at least partially defines a bottom chamber;

a valve carried by said piston and having an open position to allow air to flow therethrough, wherein said valve has a closed position to prevent air from flowing therethrough; and

a passage that allows fluid communication between said bottom chamber and said top part of cylinder at least at one point during travel of said piston, and wherein said passage allows fluid communication between said bottom chamber and said bottom part of cylinder at least at one point during travel of said piston.

11. The compressor as set forth in claim 10, further comprising a flat valve, wherein in the closed position of said valve a flat surface is formed on the top of said top part of said piston, wherein said flat valve and said flat surface contact one another at least at one point during travel of said piston.

12. The compressor as set forth in claim 11, wherein at least at some point during an up stroke of said piston air pressure in said top part of cylinder increases in order to open said flat valve to subsequently cause air in said top part of cylinder to be released across said flat valve and out of an outlet, and wherein subsequent to releasing air from said top part of cylinder across said flat valve and out of said outlet said flat valve and said flat surface of said top part of said piston contact one another, wherein a surface of said flat valve and said flat surface of said top part of said piston are mirror-polished.

13. The compressor as set forth in claim 10, wherein at least at some point during a down stroke of said piston said bottom part of said piston compresses air in said bottom chamber, and further comprising a bottom part of cylinder valve that is open at least at some point during a down stroke of said piston to allow air to enter said bottom part of cylinder.

14. The compressor as set forth in claim 13, wherein said bottom part of cylinder valve is a semi-circular flat metal valve.

15. The compressor as set forth in claim 10, wherein said valve is in said open position at least at some point during a down stroke of said piston to allow air in said bottom chamber to flow through said piston and out of said valve and into said top part of cylinder.

16. The compressor as set forth in claim 10, wherein said top part of said piston blocks an opening of said passage to prevent air from traveling therethrough at least at some point during a down stroke of said piston, and wherein said top part of said piston clears said opening of said passage to allow air flow from said bottom chamber to said top part of cylinder at least at some point during a down stroke of said piston.

17. The compressor as set forth in claim 10, wherein at least at some point during an up stroke of said piston air is compressed in said top part of cylinder and in said bottom part of cylinder by said piston, and further comprising a bottom chamber valve that is open at least at some point during an up stroke of said piston to allow air to enter said bottom chamber.

18. The compressor as set forth in claim 10, wherein said piston defines at least one rectangular recess having curved ends, and wherein at least at some point during the travel of said piston air is transferred from said bottom part of cylinder through said rectangular recess through said passageway and into said bottom chamber.

19. The compressor as set forth in claim 18, wherein said point during the travel of said piston in which air is transferred from said bottom part of cylinder through said rectangular recess through said passageway and into said bottom chamber occurs during the top dead center position of said piston.

20. The compressor as set forth in claim 10, wherein said bottom part of said piston has a larger diameter than said top part of said piston.

21. A compressor, comprising:

a piston cylinder;

a valve carried by said piston and having an open position to allow air to flow therethrough, wherein said valve has a closed position to prevent air from flowing therethrough;

a passage that allows fluid communication between said bottom chamber and said top part of cylinder at least at one point during travel of said piston, and wherein said passage allows fluid communication between said bottom chamber and said bottom part of cylinder at least at one point during travel of said piston;

a flat valve, wherein in the closed position of said valve a flat surface is formed on the top of said top part of said piston, wherein said flat valve and said flat surface contact one another at least at one point during travel of said piston; and

a bottom part of cylinder valve that is open at least at some point during a down stroke of said piston to allow air to enter said bottom part of cylinder;

wherein said top part of said piston clears an opening of said passage to allow air flow from said bottom chamber to said top part of cylinder at least at some point during a down stroke of said piston;

wherein said piston defines at least one rectangular recess having curved ends, and wherein at a top dead center position of said piston air is transferred from said bottom part of cylinder through said rectangular recess through said passageway and into said bottom chamber.