US20080063551A1

US20080063551A1 - Head Discharging Compressor System

Info

Publication number: US20080063551A1
Application number: US11/531,425
Authority: US
Inventors: James P. Cornwell
Original assignee: R Conrader Co
Current assignee: R Conrader Co
Priority date: 2006-09-13
Filing date: 2006-09-13
Publication date: 2008-03-13
Also published as: WO2008033677A2; WO2008033677A3

Abstract

A cylinder arrangement for a reciprocating air compressor system includes a compressor pump having a compression cylinder and piston. An inlet valve moves to an open position and allows air to enter the compression cylinder through an inlet valve clearance during intake strokes of the piston. The inlet valve moves to a closed position and prevents air from exiting the compression cylinder through the inlet valve clearance during compression strokes of the piston.

An orifice has a minimum cross sectional area smaller than the inlet valve clearance. The orifice allows air to enter the compression cylinder during intake strokes of the piston and allows air to exit the compression cylinder during piston compression strokes. The amount of air passing through the orifice is significantly less than the amount of air passing through the inlet valve clearance during each intake stroke. The orifice relieves backpressure within the compression cylinder.

Description

BACKGROUND

Reciprocating air compressor systems are used to provide compressed air for the operation of various types of mechanical and pneumatic devices. Such systems are manufactured in a broad range of sizes and capacities that allow for air deliveries that vary from less than 1 Standard Cubic Foot per Minute (“SCFM”) to more than 100 SCFM. A piston is commonly employed to reciprocate with repeated intake and compression strokes within a compression cylinder. In most reciprocating compressor systems, an arrangement of valves allows air to be drawn from the environment surrounding the compressor system through at least one inlet valve into a compression cylinder where the air is compressed. The compressed air is then channeled through at least one outlet valve and a discharge tube into an air reservoir where air is stored. The air pressure within the air reservoir is normally maintained within a predetermined pressure range by the operation of the compressor.
An air reservoir check valve allows compressed air at a pressure greater than that of the reservoir to flow from the compressor through the discharge tube and into the reservoir. The air reservoir check valve also prevents air from flowing from the reservoir back into the discharge tube when the compressor is off. However, when the compressor turns off, a residual pressure, called a back pressure, remains within the discharge tube and on the piston within the compression cylinder when the compressor starts up again.
It is usually desirable to relieve back pressure on the piston when the piston is not reciprocating within the compression cylinder since the piston must overcome this back pressure as it starts to compress air. Relieving the back pressure significantly improves the performance of the compressor system and extends the operational life of the compressor pump. To relieve back pressure, compressor systems often employ a bleed orifice downstream from the compression cylinder sometimes included as part of an air reservoir check valve. The bleed orifice continuously allows compressed air to flow to the surrounding atmosphere from the discharge tube and connected compression cylinder. When the piston is not reciprocating within the compression cylinder, the bleed orifice unloads backpressure from the piston at a preselected rate of unloading determined by the diameter of the bleed orifice.
When the piston reciprocates within the compression cylinder, the larger clearance of the open outlet valve from the compression chamber and the larger diameter of the discharge tube, compared to the significantly smaller diameter of the bleed orifice, allow an amount of air to be compressed that is sufficient to increase pressurization of the air reservoir. However, as a result of the downstream location of the bleed orifice from the compression cylinder, compressed air is discharged continuously from the bleed orifice while the piston reciprocates within the compression cylinder. Thus, some air pressure within the discharge tube is wasted continuously through the bleed orifice as the piston reciprocates. This causes an inherent inefficiency in the compressor system that is directly related to the amount of air pressure lost through the bleed orifice.
Compressor systems can also become less efficient if the compression cylinder is not substantially sealed from the discharge tube during intake strokes of the piston. During each compression stroke, air that has been compressed and that has moved downstream through the discharge tube tends to acquire additional heat energy. If the compressed air subsequently escapes from the discharge tube back into the compression cylinder, the heated, previously compressed air may be less dense than cooler air entering the compression cylinder through the inlet valve.
The escape of air from the discharge tube back to the compression cylinder can be caused by an incompletely sealed outlet valve or another opening between the compression cylinder and discharge tube. The resulting leakage of air between the compression cylinder and discharge tube during intake strokes of the piston can produce a condition known as reversion. In this condition, since the heated, previously compressed air present within the compression cylinder can have a density less than cooler air entering through the inlet valve, thee amount of air taken from the atmosphere during each piston stroke is reduced and can lead to lower compressed air production by the compressor.
If the compression chamber outlet valve is not substantially leak free or if a bleed orifice is located downstream of the outlet valve at a location such as the discharge tube, the discharge tube will be unable to sustain the pressure of compressed air within the air reservoir when the piston is not reciprocating. As a result, an additional check valve is normally required to maintain air pressure within the compression cylinder. The inclusion of such additional components can significantly increase the overall unit construction cost of the compressor system.
Such typical limitations of prior art systems can be best understood with reference to the example prior art reciprocating air compressor system 20 depicted in FIGS. 1-3. Referring first to the partial cross sectional view of the compressor system 20 depicted in FIG. 1, the compressor system 20 includes an air compressor pump 22 having a compression cylinder 24 in which a piston 26 is positioned to reciprocate in intake strokes (downward in FIG. 1) and compression strokes (upward in FIG. 1). The piston 26 is powered with an electric motor 28 that actuates the piston 26 using a belt 30, flywheel pulley 32, and crankshaft 34, connected to the piston 26 via a piston rod and pin assembly 35. The belt is moved by engaging a pulley (not shown) attached to the rotating shaft (not shown) of the meter 28. The moving belt rotates the flywheel pulley 32 that it engages, rotating the crankshaft 34 that is attached to the pulley 32. The rotating crankshaft 34 causes the piston rod and pin assembly 35, and thus the piston 26, to reciprocate within the compression chamber 24. The compressor pump 22 and electric motor 28 are mounted on an air reservoir 36.
As the piston 26 reciprocates within the compression cylinder 24, each intake stroke of the piston 26, during which the piston 26 moves in a downward direction in the compression chamber 24, causes air to be drawn from the environment surrounding the compressor system 20 through an air filter 40 into a cylinder inlet chamber 42. Referring briefly to FIG. 2, which depicts a magnified cross sectional view of the compressor pump 22, a first reed valve serves as an inlet valve 44. The inlet valve 44 allows a unidirectional flow of air from the cylinder inlet chamber 42 to the compression cylinder 24 throughout the duration of the intake stroke since the pressure created by the downward direction of the stroke pulling the reed of the valve 44 into the compression chamber 24. A second reed valve serves as an outlet valve 46, which is also unidirectional and prevents air from being drawn from a cylinder outlet chamber 48 and a discharge tube 50 connected to it throughout the duration of the intake stroke since the pressure created by the downward intake stroke tends to pull the reed of the outlet valve 40 toward the compression chamber 24. However, the outlet valve 46 does not completely seal the cylinder outlet chamber 48 from the compression cylinder 24 during the duration of the intake stroke. As a result, any backpressure present within the cylinder outlet chamber 48 which would be at a higher pressure than the pressure within the compression cylinder 24 during the downward stroke, can result in some pressurized air entering the compression chamber through the outlet valve 46 during the intake stroke.
During each compression stroke, the piston (not shown in FIG. 2) moves in an upward direction in the compression cylinder 24 and thus forces air through the outlet valve 46 and into the cylinder outlet chamber 48. The inlet valve 44, which is then forced against the valve plate at the top of the compression chamber 24, prevents air from flowing back through the inlet valve 44 and into the cylinder inlet chamber 42. Any air that has returned or reverted to the cylinder outlet chamber 48 back from the discharge tube 50 and the outlet chamber 48 and through outlet valve 46 during the intake stroke ultimately leads to a reduction in the overall amount of air that has been compressed and leads to an increase in intake air temperature leading to lower compressed air production and lower efficiency of the compressor system 20.
Referring again to FIG. 1, as the piston 26 reciprocates within the compression cylinder 24, air that has been compressed and forced through the outlet valve 46 flows through the cylinder outlet chamber 48 to a discharge tube 50 which channels air to a reservoir check valve 52. FIG. 3 depicts a magnified partial cross sectional view of the reservoir check valve 52 connecting the discharge tube 50 to the air reservoir 36.
As best understood by comparing FIG. 1 to FIG. 3, the reservoir check valve 52 includes a valve body 53 and a bleed orifice 54 that is open to the interior cross section of the discharge tube 50 and to the atmosphere surrounding the air compressor system 20. The bleed orifice 54 allows air pressure to constantly escape from the discharge tube 50 and thereby slowly removes backpressure from the cylinder outlet chamber 48 when the piston 26 is not reciprocating in the compression cylinder 24.
The reservoir check valve 52 also includes a plug 56 having a tapered section 58. The plug 56 is shaped with flutes 57 (shown in FIG. 3) to allow an air passage 59 to extend from within the valve body 53 to the air reservoir 36. An elastomeric o-ring 60 is positioned to reciprocate on the tapered section 58 of the plug 56. The o-ring 60 is biased away from an o-ring stop 62 to a closed valve position (shown in FIG. 3) where the o-ring 60 seals between the valve body 53 and the plug 56 to prevent air from passing through the air passage 59 into the air reservoir 36.
When the piston 26 reciprocates in the compression cylinder 24, air forced through the outlet valve 46 by compression strokes of the piston 26 pressurizes the cylinder outlet chamber 48 and discharge tube 50. Some air from within the cylinder outlet chamber 48 escapes back through the unsealed outlet valve 46 through reversion during each subsequent intake stroke of the piston 26. As long as air pressure within the discharge tube 50 is greater than in the environment surrounding the air compressor system 20, air flows continuously through the bleed orifice 54 to slowly but constantly remove air pressure within the discharge tube 50. If the air pressure within the discharge tube 50 is initially sufficient to exert a cracking force against the o-ring 60 of the reservoir check valve 52 and remains sufficiently greater than the air pressure contained within the air reservoir 36 to overcome the biasing force of the o-ring 60, the o-ring 60 is forced to stretch outward and down the tapered section 58 toward the o-ring stop 62 to an open position (not shown in FIG. 3). This open position of the o-ring 60 allows air to flow from the discharge tube 50 into the air reservoir 36.
Although some compressed air from the valve outlet chamber 48 is lost by reversion during intake strokes of the piston 26 and although some pressurized air is constantly lost during operation of the compressor 22 through the bleed orifice 54, the rate at which air is lost is less than the rate at which air can be compressed by the reciprocating piston 26. The cross sectional areas of the air passage 59 (see FIG. 3) and open position clearance between the o-ring 60 and valve body 53 are also sufficiently large to allow flowing compressed air to enter the air reservoir 36 faster than air can be removed by reversion or through the bleed orifice 54. The bleed orifice 54 serves a useful function of removing backpressure from the discharge tube 50 and cylinder outlet chamber 48 when the piston 26 is not reciprocating, reducing the initial load against the piston 26 and therefore reducing the initial burden on the motor 28 at the start of system operation. However, as long as the compressor pump 22 continues to compress air, reversion constantly reduces the efficiency of the compressor pump 22 and air loss through the bleed orifice 54 occurs at a continuous rate.

SUMMARY

A cylinder arrangement for a reciprocating air compressor system includes a compressor pump having a compression cylinder. A piston is positioned to reciprocate with intake and compression strokes within the compression cylinder. An inlet valve has open and closed positions, an inlet valve clearance being present in the inlet valve when the inlet valve is in the open position. The inlet valve moves to the open position and allows air to enter the compression cylinder through the inlet valve clearance during intake strokes of the piston. The inlet valve moves to the closed position and prevents air from exiting the compression cylinder through the inlet valve clearance during compression strokes of the piston.
An orifice has a minimum cross sectional area smaller than the effective area of the inlet valve clearance. The orifice is positioned to allow air to enter the compression cylinder during intake strokes of the piston and to allow air to exit the compression cylinder during compression strokes of the piston. The amount of air passing through the orifice is significantly less than the amount of air passing through the inlet valve clearance during each intake stroke. When the piston is not reciprocating within the compression cylinder, remaining backpressure within the compression cylinder is relieved through the orifice.
A second embodiment also includes a discharge tube and allows compressed air to flow from the compressor pump to an air reservoir. An outlet valve having open and closed positions moves to the open position and allows air to exit the compression cylinder and enter the discharge tube during compression strokes of the piston. The outlet valve moves to the closed position and prevents air from entering the compression cylinder through the outlet valve during intake strokes of the piston. The outlet valve also moves to the closed position to prevent air from the discharge tube and air reservoir from entering the compression cylinder through the outlet valve when the piston is not reciprocating in the compression cylinder. The outlet valve is constructed so that when in the closed position it is substantially leak free and is generally capable of sealing the backpressure of the discharge tube to preserve the pressure of compressed air in the air reservoir.
The placement of the orifice to allow air to enter the compression cylinder through the orifice during intake strokes of the piston and to only allow air to exit the compression cylinder through the orifice during compression strokes of the piston allows for an approximately 50% reduction in the amount of compressed air that is wasted through the orifice while the piston reciprocates within the compression cylinder. This is done without reducing the ability of the orifice to remove backpressure from the piston when the piston is not reciprocating.
This placement of the orifice allows for the usage of a substantially leak free valve, such as an elastomeric o-ring valve, as an outlet valve. If the outlet valve is substantially leak free, it is possible to use outlet valve to seal and allow for pressure of the air reservoir to be maintained within the discharge tube, eliminating the need for an additional check valve to prevent the escape of air pressure from the air reservoir to the surrounding atmosphere.
The use of a substantially leak free valve prevents the leaking or reversion of compressed air back through the outlet valve when the outlet valve is closed during intake strokes of the piston. This allows for an increase in the amount of air that can be drawn into the pump from the surrounding atmosphere and leads to greater efficiency of the compressor pump.
In some embodiments, the use of a substantially leak free valve, such as an elastomeric o-ring valve, as an outlet valve also allows for improved cooling of the compressor pump since a hollow valve shaft can be used to enhance the transfer of heat to cooler air flowing throughout the cooling fins and across the cylinder head of the pump.
Those skilled in the art will realize that this invention is capable of embodiments that are different from those shown and that details of the structure of the disclosed arrangement can be changed in various manners without departing from the scope of this invention. Accordingly, the drawings and descriptions are to be regarded as including such equivalent arrangements as do not depart from the spirit and scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding and appreciation of this invention, and many of its advantages, reference will be made to the following detailed description taken in conjunction with the accompanying drawings.

FIG. 1 depicts a partial cross sectional view of a reciprocating air compressor system of the prior art;

FIG. 2 depicts a magnified cross sectional view of inlet and outlet valves within the prior art compressor system of FIG. 1;

FIG. 3 depicts a magnified partial cross sectional view of a reservoir valve and bleed orifice of the prior art compressor system of FIG. 1;

FIG. 4 depicts a partial cross sectional view of a reciprocating air compressor system of the invention;

FIG. 5 depicts a magnified partial cross sectional view of the reciprocating air compressor system of FIG. 4 during an intake stroke of the piston;

FIG. 6 depicts a more highly magnified cross sectional view of the orifice pin and adjacent components depicted in FIG. 5;

FIG. 7 depicts a magnified partial cross sectional view of the reciprocating air compressor system of FIG. 4, the piston being located at a bottom dead center position;

FIG. 8 depicts a magnified partial cross sectional view of the reciprocating air compressor system of FIG. 4 during a compression stroke of the piston;

FIG. 9 depicts a magnified partial cross sectional view of the reciprocating air compressor system of FIG. 4, the piston being located at a top dead center position;

FIG. 10 is an exploded top perspective view of components of the compressor pump of FIG. 4;

FIG. 11 is an exploded bottom perspective view of the air compressor components depicted in FIG. 10;

FIG. 12 depicts a side cross sectional view of compressor pump used with a compressor system according to one embodiment of the invention;

FIG. 13 depicts a side cross sectional view of compressor pump used with a compressor system according to one embodiment of the invention;

FIG. 14 depicts a side cross sectional view of compressor pump used with a compressor system according to one embodiment of the invention;

FIG. 15 depicts a side cross sectional view of compressor pump used with a compressor system according to one embodiment of the invention;

FIG. 16 depicts a side cross sectional view of compressor pump used with a compressor system according to one embodiment of the invention;

FIG. 17A depicts a magnified, perspective exploded view of the outlet valve used with the compressor pump of FIG. 16;

FIG. 17B depicts a magnified, side cross sectional view of the outlet valve used with the compressor pump of FIG. 16, the outlet valve being in the closed position;

FIG. 17C depicts a magnified, side cross sectional view of the outlet valve used with the compressor pump of FIG. 16, the outlet valve being in the closed position;

FIG. 18A depicts a magnified, side cross sectional view of the inlet valve used with the compressor pump of FIG. 16, the inlet valve being in the closed position; and

FIG. 18B depicts a magnified, side cross sectional view of the inlet valve used with the compressor pump of FIG. 16, the outlet valve being in the closed position.

DETAILED DESCRIPTION

Referring again to the drawings, identical reference numerals and letters designate the same or corresponding parts throughout the several figures shown on the drawings. In some drawings, some specific embodiment variations in corresponding parts are denoted with the addition of lower case letters and/or prime indicators to reference numerals.
A reciprocating air compressor system 64 a according to the invention is depicted in FIG. 4. The air compressor system 64 a includes an air compressor pump 66 a having a compression cylinder 68 a and a piston 70 powered with an electric motor 72 that actuates the piston 70 using a belt 74, flywheel pulley 76, and crankshaft 78, connected to the piston 70 via a piston rod and pin assembly 79. The compressor pump 66 a and electric motor 72 are mounted on an air reservoir 80.
Referring to FIGS. 5 and 7-9, which depicts a magnified partial cross sectional view of the compressor pump 66 a during an intake stroke of the piston 70, each intake stroke causes air to be drawn from the atmosphere surrounding the compressor system 64 a through an air filter 82 a and head assembly 83 a into a cylinder inlet chamber 84 a. A reed valve serves as an inlet valve 86 a allowing a unidirectional flow of air from the cylinder inlet chamber 84 a to the compression cylinder 68 a throughout the duration of each intake stroke.
An orifice 88 a is positioned on a hollow orifice pin 90 a to allow airflow between the cylinder inlet chamber 84 a and compression cylinder 68 a. FIG. 6 is a magnified cross sectional view of the orifice pin 90 a and orifice 88 a depicting the comparative sizing of the minimum cross sectional size of the orifice 88 a with the orifice pin 90 a and adjacent components.
Referring again to FIGS. 5 and 7-9, both the inlet valve 86 a and orifice pin 90 a/ orifice 88 a are positioned on a cylinder valve plate 92 a that is located between the cylinder inlet chamber 84 a and compression cylinder 68 a. Air is therefore allowed to also pass through the cylinder valve plate 92 a when passing through the inlet valve 86 a and orifice 88 a. As shown in FIG. 5, the inlet valve 86 a assumes an open position during each intake stroke of the piston 86 a, creating an inlet valve clearance 87 a with the cylinder valve plate 92 a through which air passes from the cylinder inlet chamber 84 a and compression cylinder 68 a during the intake stroke.
As best understood by comparing FIGS. 5 and 6, when the inlet valve 86 a assumes the open position (shown in FIG. 5) during the intake stroke of the piston 70, the inlet valve clearance 87 a of the open inlet valve 86 a is sufficiently large to allow a substantial amount of air to enter the compression cylinder 68 a. Further comparing FIGS. 5 and 6, the minimum cross sectional size of the orifice 88 a is smaller than the inlet valve clearance 87 a of the inlet valve 86 a that is in the open position during the intake stroke. Thus, a smaller amount of air enters the compression cylinder 68 a through the orifice 88 a than through the inlet valve 86 a during the intake stroke.
The size of the inlet valve clearance 87 a and the corresponding amount of air that can be admitted during each intake stroke is dependent on the size and configuration of the inlet valve 86 a. FIG. 10 depicts an exploded top perspective view of some components from the compressor pump 66 a including the head assembly 83 a, cylinder valve plate 92 a, inlet valve 86 a, and orifice pin 90 a. As best understood with reference to FIG. 10, the inlet valve 86 a includes a valve tab 94 a disposing multiple reeds 96 a in a fanlike configuration. The inlet valve 86 a is constructed of a flexible material having a memory shape such as plastic or metal that enables the inlet valve 86 a to be biased to the closed position. The orifice pin 90 a fits through a spacer hole 97 a of a spacer 98 a, a tab hole 100 a of the inlet valve 86 a, and pin fastening hole 102 a of the cylinder valve plate 92 a to secure and position the inlet valve 86 a to the valve plate 92 a.
FIG. 11 depicts an exploded bottom perspective view of the air compressor components depicted in FIG. 10. As best understood with reference to FIG. 11, the inlet valve 86 a fits within a valve recess 104 a when attached to the cylinder valve plate 92 a. A separate inlet hole 106 a extending from the valve recess 104 a through the cylinder valve plate 92 a corresponds to each reed 96 a of the inlet valve 86 a. As best understood by comparing FIG. 5 with FIGS. 10 and 11, a feature of this embodiment of the invention is that the total inlet valve clearance of the inlet valve 86 a is the combined total of the individual inlet valve clearances 87 a of each reed 96 a. Accordingly, the total amount of air that can be admitted through the inlet valve 86 a into the compression cylinder 68 a during each intake stroke of the piston 70 is the combined total amount of air that can be admitted past each reed 96 a and corresponding inlet hole 106 a during each intake stroke. Thus, the total amount of air that can be admitted through the inlet valve 86 a is much greater, and often several orders of magnitude greater, than the amount of air that that can be admitted through the orifice 88 a during each intake stroke. Although it will be appreciated that the ratio of the minimum cross sectional size of the orifice 88 a to the total inlet valve clearance of the inlet valve 86 a can vary greatly, all such ratios will allow for a total amount of air that can be admitted through the inlet valve 86 a to be greater than the amount that can be admitted through the orifice 88 a during each intake stroke of the piston 70. Such ratios are typically on the order of 1:2,000, and can commonly range from 1:1,000 to 1:4,000, though both larger and smaller ratios are within the contemplated scope of the invention.
Referring again to FIG. 5, an elastomeric o-ring check valve serves as a unidirectional outlet valve 108 a. As best understood by comparing the side cross sectional view of FIG. 5 with the bottom perspective exploded view of FIG. 11, the outlet valve 108 a is constructed around a hollow valve shaft 110 a that is formed from a shaped recess of the head assembly 83 a. Being hollow, the valve shaft 110 a is open at the top to allow air from the surrounding environment to cool the outlet valve 108 a and compressor pump interior with the assistance of cooling fins 112 a. The valve shaft 110 a extends through a cylinder outlet chamber 114 a of the air compressor pump 66 a to an outlet hole 116 a through the cylinder valve plate 92 a.
As best understood with a further comparison of FIGS. 5 and 6-9 with FIG. 11, the valve shaft 110 a includes a cylindrically shaped non-tapered section 118 a and an adjacent semi-conically shaped tapered section 120 a, the tapered section 120 a increasing in diameter in a direction that is away from the outlet hole 115 a. An elastomeric sealing ring 122 a is positioned in the cylinder outlet chamber 114 a around the non-tapered section 118 a to reciprocate between the cylinder valve plate 92 a and the tapered section 120 a. The sealing ring 122 a is biased to a closed position (as shown in FIGS. 5, 7, and 9) by an elastomeric actuation ring 124 a that is positioned in the cylinder outlet chamber 114 a around the tapered section 118 a of the valve shaft 110 a. The actuation ring 124 a has a memory shape that is generally smaller than the smallest diameter of the tapered section 120 a, causing the actuation ring 124 a to move in a direction along the tapered section 118 a that is toward the outlet hole 116 a, biasing the sealing ring 122 a to the closed position.
The sealing ring 122 a and actuation ring 124 a are constructed from materials selected for having optimal properties for their respective functions and interactions. For example, one suitable combination is the use of a Teflon sealing ring 122 a with a silicone elastomer actuation ring 124 a. In such a combination, the Teflon material of the sealing ring 122 a provides effective sealing and low frictional resistance to the operation of the outlet valve 108 a while the silicone material of the actuation ring 124 a is effective for providing elasticity, high-temperature resistance, and hardening resistance while retaining viscosity. Other possible actuation ring materials include nitrile elastomers and viton elastomers. Other possible sealing ring materials include viton elastomers, hard nitrate elastomers, brass, and stainless steel.
Although the invention is shown and described in FIGS. 4-5 and 7-11 with an outlet valve 108 a having a separate sealing ring 122 a and actuation ring 124 a, it will be appreciated that some contemplated embodiments of the invention may include an outlet valve using a single elastomeric o-ring. In such embodiments, the single elastomeric o-ring will generally be constructed of a material that is suitable for performing both actuation and sealing functions of the outlet valve.
Referring again to FIGS. 4-11, when the sealing ring 122 a, under the bias of the actuation ring 124 a, assumes the closed position shown in FIGS. 5, 7, and 9, the sealing ring 122 a makes sealing contact with the cylinder valve plate 92 a to create a substantially leak free sealing closure of the outlet hole 116 a, preventing the movement of air from the cylinder outlet chamber 114 a back into the compression cylinder 86 a.
As best understood by comparing FIGS. 4 with FIGS. 5 and 7-9, a discharge tube 126 a connects the cylinder outlet chamber 114 a to the air reservoir 80. Since the sealing closure of the outlet hole 116 a by the sealing ring 122 a in the closed position is substantially leak free, the sealing closure is sufficient to allow the outlet valve 108 a to prevent air pressure from the discharge tube 126 a and cylinder outlet chamber 114 a from flowing back into the compression cylinder 68 a. The sealing closure therefore enables the outlet valve 108 a to maintain air pressure that is present within the outlet chamber 114 a. Thus, when the piston 70 is not reciprocating in the compression cylinder 68 a, the outlet valve 108 a is also capable of preventing the loss of air pressure within the discharge tube 126 a and air reservoir 80.
The ability of the outlet valve 108 a to maintain air pressure in the outlet chamber 114 a, discharge tube 126 a, and air reservoir 80 eliminates the need for a separate reservoir check valve to preserve air pressure in the air reservoir 80 and further eliminates the need for a bleed orifice 54 a to remove back pressure within the discharge tube 126 a and outlet chamber 114 a when the piston 70 is not reciprocating within the compression cylinder 68 a. As depicted in FIG. 4, the discharge tube 124 a and outlet chamber 114 a are therefore constructed to be open to the air reservoir 80 via an open tube coupling 128 a. Accordingly, an air pressure that is approximately the same as that present within the air reservoir 80 remains present within the discharge tube 124 a and outlet chamber 114 a when the sealing ring 122 a is in the closed position, which is also the closed position of the outlet valve 108 a.
It is usually desirable to remove backpressure that may remain in the compression cylinder 68 a when the piston 70 is not reciprocating. Since the orifice 88 a is much smaller than the inlet valve clearance 87 a of the open inlet valve 86 a, air passes through the orifice 88 a at a much slower rate than through the inlet valve 86 a during the intake stroke. However, given the typical length of intervals during which the piston 70 is not reciprocating within the compression cylinder 68 a, the removal of such backpressure can normally proceed at a rate that is much slower than the rate at which air is compressed by the piston 70. Therefore, the orifice 88 a can be used for the removal of backpressure from the compression cylinder 68 a.
The advantages of using the orifice 88 a to remove backpressure in conjunction with an outlet valve according to the invention are best understood by comparing FIGS. 5-9 with the prior art compressor system 20 of FIGS. 1-3. FIG. 5 depicts the air compressor pump 66 a of FIG. 4 during an intake stroke of the piston 70. Air from the atmosphere surrounding the compressor pump 66 a is drawn through the air filter 82 and cylinder inlet chamber 84 a through the inlet valve clearance 87 a of the inlet valve 86 a. Although the cross sectional area of the inlet valve clearance 87 a of the inlet valve 86 a is much larger than the orifice 88 a, and although most of the air drawn into the compression cylinder 68 a during the intake stroke consequently enters through the inlet valve 86 a, a comparatively small amount of air also enters the compression cylinder 68 a through the orifice 88 a during the intake stroke.
Since air is drawn into the compression cylinder 68 a during the intake stroke, the outlet valve 108 a assumes the closed position, with the sealing ring 122 a moving into sealing contact with the cylinder valve plate 92 a due to the bias of the actuation ring 124 a and suction forces of the piston 70. The sealing contact between the sealing ring 122 a and cylinder valve plate 92 a in the closed position makes the outlet valve 108 a substantially leak free. Thus, the outlet valve 108 a is sufficient to prevent air from the discharge tube 125 a and cylinder outlet chamber 114 a from entering or reverting into the compression cylinder 68 a during the intake stroke. This sealing effect substantially reduces inefficiencies of the compressor pump 66 a that could otherwise be caused by reversion.
FIG. 7 depicts the compressor pump 66 a with the piston 70 in a bottom dead center position between the intake and compression strokes. FIG. 7 also depicts the inlet valve 86 a and outlet valve 108 a in closed positions and can therefore also be considered to represent the compressor pump 66 a when the piston 70 is not reciprocating within the compression cylinder 68 a.
Consider the compressor pump 66 a when the piston 70 is not reciprocating within the compression cylinder 68 a. The sealing ring 122 a moves to the closed position, as depicted in FIG, 7, to seal against the cylinder valve plate 92 a and prevent the loss of air pressure within the air reservoir 80, discharge valve 126 a, and cylinder outlet chamber 114 a. The compressor system 64 a of FIGS. 4-11 includes no orifice similar to the bleed orifice 54 of the prior art compressor system 20 of FIGS. 1-3 and therefore allows air pressure within the air reservoir 80 to be maintained in the air reservoir 80, discharge valve 126 a, and cylinder outlet chamber 114 a.
Backpressure remaining in the compression cylinder 68 a is relieved through the orifice 88 a into the cylinder inlet chamber 84 a and surrounding environment without affecting the air pressure contained within the air reservoir 80, discharge valve 126 a, and cylinder outlet chamber 114 a. This release of backpressure occurs without the need for an additional check valve and bleed mechanism such as the reservoir check valve 52 and bleed orifice 54 in the prior compressor system 20 of FIGS. 1-3, reducing the overall number of components in the compressor system 64 a of the invention in FIGS. 6-11.
Now consider FIG. 8, which depicts the compressor pump 66 a during a compression stroke (upward in FIG. 8) of the piston 70. As the piston 70 moves upward and compresses air, the sealing ring 122 a moves out of sealing contact with the cylinder valve plate 92 a and against the bias of the actuation ring 124 a to the open position of the outlet valve 108 a (depicted in FIG. 8) to create an outlet valve clearance 130 a that allows the compressed air to flow from the compression cylinder 68 a through the outlet hole 116 a of the valve plate 92 a into the cylinder outlet chamber 114 a and discharge tube 126 a. The sealing ring 122 a and outlet valve 108 a remain in the open position at least until the piston 70 completes the compression stroke and reaches a top dead center position within the compression cylinder 68 a as depicted in FIG. 9. Referring briefly to FIG. 9, once the compression stroke has been completed, the sealing ring 122 a returns to the depicted closed position under the combined forces of the actuation ring 124 a and any backpressure that may be present within the cylinder outlet chamber 114 a.
Referring again to FIG. 8, the inlet valve 86 a moves to a closed position during the compression stroke to prevent air from escaping through the inlet valve 86 a back into the cylinder inlet chamber 84 a. Some compressed air does escape through the orifice 88 a during the compression stroke. However, as best understood by comparing FIG. 8 with the magnified cross sectional view of the orifice 88 a and orifice pin 90 a in FIG. 8, while the sealing ring 122 a remains in the open position, the cross sectional size of the outlet valve clearance 130 a is substantially larger than that of the orifice 88 a. Due to this difference in cross sectional sizing, a much larger amount of air enters the cylinder outlet chamber 114 a than the cylinder inlet chamber 84 a during each intake stroke. As a result, the net air flow through the compressor pump 66 a during a complete intake and compression stroke (reciprocation) of the piston 70 results in positive air compression through the cylinder outlet chamber 114 a and discharge tube 126 a to the air reservoir 80.
Although reciprocation of the piston 70 results in some air being lost through the orifice 88 a during each compression stroke, the positioning of the orifice 88 a between the cylinder inlet chamber 84 a and compression cylinder 68 a and the use of the substantially leak free outlet valve 108 a allows for a substantial reduction in the overall amount of compressed air that is wasted. Rather than being bled continuously, air is lost from the compression cylinder 86 a through the orifice 88 a to the inlet chamber 84 a only during each compression stroke. After a quantity of air is lost through the orifice 88 a during each compression stroke, a roughly equal amount of air is drawn back through the orifice 88 a from the cylinder inlet chamber 84 a to the compression cylinder 68 a during each subsequent intake stroke. Air is not lost through the orifice 88 a during the intake strokes.
By limiting the loss of compressed air through the orifice 88 a to compression strokes, the invention increases the overall efficiency of the compressor system 64 a. For example, since the placement of the bleed orifice 54 in the prior art compressor system 20 of FIGS. 1-3 is positioned downstream of the compression cylinder 24 and outlet valve 46, the loss of compressed air from the discharge tube 50 through the bleed orifice 54 is constant while the piston 26 reciprocates within the compression cylinder 24. However, since the placement of the orifice 88 a in the compressor system 64 a of the invention of FIGS. 4-11 allows for the loss of compressed air through the orifice 88 a only during compression strokes, the amount of compressed air lost during piston reciprocation in reduced to approximately 50% of the level lost by the prior art compressor system 64 a depicted in FIGS. 1-3.
Referring to FIG. 9, the compressor pump 66 a is depicted with the piston 70 in a top dead center position between the compression and intake strokes. FIG. 9 also depicts the inlet valve 86 a and outlet valve 108 a in closed positions and can therefore also be considered to represent the compressor pump 66 a when the piston 70 is not reciprocating within the compression cylinder 68 a. Once piston reciprocation has ended, the sealing contact of the sealing ring 118 a with the cylinder valve plate 92 a is sufficient to allow the outlet valve 108 a to preserve air pressure within the cylinder outlet chamber 114 a, discharge tube 126 a, and air reservoir 80 until the piston 70 is again reciprocated or the air pressure contained within the reservoir 80 is consumed. However, it will be appreciated that other types of outlet valves can be similarly implemented within the intended scope of the invention and also allow for substantially leak free sealing of air pressure.
For example, FIG. 12 depicts a side cross sectional view of compressor pump 66 b used with a compressor system 64 b according to one embodiment of the invention in which a check valve is used as an outlet valve 108 b. The outlet valve 108 b extends downward from the head assembly 83 b on a valve stanchion 132 b toward the outlet hole 116 b. A valve piston 134 b is positioned to reciprocate (vertically in FIG. 12) along the valve stanchion 132 b.
The valve piston 134 b is constructed of a polymer, elastomer, rubber, or other material suitable for creating a sealing contact with the cylinder valve plate 92 b. A valve spring 136 b biases the valve piston 134 b to a closed position that is also the closed position of the outlet valve 108 b and depicted in FIG. 12. In the closed position, the valve piston 134 b contacts the cylinder valve plate 92 b over and around the outlet hole 116 b to seal the outlet hole 116 b and prevent air from moving from the cylinder outlet chamber 114 b to the compression cylinder 68 b.The material of the valve piston 134 b allows the outlet valve 108 b to be substantially leak free in the closed position and therefore prevents compressed air within the outlet chamber 114 b, discharge tube 126 b, and reservoir (not shown in FIG. 12) from flowing back into the compression cylinder 68 b.
When the piston 70 reciprocates within the compression cylinder 68 b, the valve piston 134 b moves against the bias of the valve spring 136 b away from sealing contact with the cylinder valve plate 92 b to an open position (not shown) during each compression stroke. The open position results in an outlet valve clearance that allows air to exit the compression cylinder 68 b through the outlet hole 116 b. The inlet valve 86 b closes to prevent air from exiting the compression cylinder 68 b through the inlet hole 106 b. Although some air escapes the compression cylinder 68 b into the inlet chamber 84 b through the orifice 88 b, the cross sectional size of the outlet valve clearance of the outlet valve 108 b is much larger than the orifice 88 b, resulting in a net movement of compressed air into the outlet chamber 114 b and discharge tube 126 b. During subsequent intake strokes, the valve piston 134 b moves back into the closed position and prevents backpressure from flowing back into the compression cylinder 68 b while the inlet valve 86 b opens to allow air to enter the compression cylinder 68 b from the inlet chamber 84 b.
It is contemplated that in some embodiments of the invention, orifices provided to relieve compression cylinder backpressure may be reconfigured or combined with other compressor components. For example, FIG. 13 depicts a side cross sectional view of a compressor pump 66 c used with a compressor system 64 c according to one embodiment of the invention in which orifices 88 c extend through each reed 96 c of the inlet valve 86 c.
During each intake stroke of the piston 70, the inlet valve 86 c opens to allow a valve clearance that is much larger than each orifice 88 c, allowing a substantial amount of air to enter the compression cylinder 68 c while the outlet valve 108 c prevents backpressure in the outlet chamber 114 c from flowing through the outlet hole 116 c. During each compression stroke, the outlet valve 108 c opens and the inlet valve 106 c closes, though some compressed air escapes through the inlet hole 106 c via each orifice 88 c during the compression stroke. However, the cross sectional size of the orifice 88 c is sufficient to allow the relief of backpressure from within the compression cylinder 68 c during intervals when the piston 70 is not reciprocating. During such intervals, the outlet valve 108 c continues to seal off backpressure in the outlet chamber 114 c and discharge tube 126 c and prevent the backpressure from entering the compression cylinder 68 c.
FIG. 14 depicts a side cross sectional view of a compressor pump 66 d used with a compressor system 64 d according to one embodiment of the invention in which an orifice 88 d is contained within an air passage that is an exterior orifice tube 138 d that leads from the upstream cylinder inlet chamber 84 d through the head assembly 83 d to the exterior of the compressor pump 66 d, then directly into the compression cylinder 68 d.
During each intake stroke of the piston 70, the inlet valve 86 d opens to allow a valve clearance that is much larger than the orifice 88 d, allowing a substantial amount of air to enter the compression cylinder 68 d while the outlet valve 108 d prevents backpressure in the outlet chamber 114 d from flowing through the outlet hole 116 d. Some air from the inlet chamber 84 d enters the compression cylinder 68 d through the orifice tube 138 d. During each compression stroke, the outlet valve 108 d opens and the inlet valve 106 d closes, though some compressed air escapes through the orifice tube 138 d and orifice 88 d back into the inlet chamber 84 d. During intervals when the piston 70 is not reciprocating, the orifice tube 138 d and orifice 88 d relieve backpressure directly from the compression cylinder 68 d into the inlet chamber 84 d without first channeling air through the inlet hole 106 d or through the cylinder valve plate 92 d.
FIG. 15 depicts a side cross sectional view of a compressor pump 66 e used with a compressor system 64 e according to one embodiment of the invention in which an orifice 88 e is contained within an air passage that is an exterior orifice tube 138 e that leads directly from the upstream exterior of the compressor pump 66 e to the compression cylinder 68 e. During each intake stroke of the piston 70, the inlet valve 86 e opens to allow a valve clearance that is much larger than the orifice 88 e, allowing a substantial amount of air to enter the compression cylinder 68 e while the outlet valve 108 e prevents backpressure in the outlet chamber 114 e from flowing through the outlet hole 116 e. Some air from exterior of the compressor pump 66 e enters the compression cylinder 68 d through the orifice tube 138 e. During each compression stroke, the outlet valve 108 e opens and the inlet valve 106 e closes, though some compressed air escapes through the orifice tube 138 e and orifice 88 e into the environment surrounding the compressor pump 66 e. During intervals when the piston 70 is not reciprocating, the orifice 88 e relieves backpressure directly from the compression cylinder 68 e into the environment surrounding the compressor pump 66 e without first channeling air through the cylinder valve plate 92 e or into the inlet chamber 84 c.
It will be further appreciated that outlet valves that are both metallic sealing check valves and substantially leak free can be implemented within the contemplated scope of the invention. It will also be appreciated that inlet valves that are substantially leak free can also be used. For example, FIG. 16 depicts a side cross sectional view of a compressor pump 66 f used with a compressor system 64 f according to one embodiment of the invention in which a metallic sealing check valve that is substantially leak free is used as an outlet valve 108 f and positioned in the outlet hole 116 f of the cylinder valve plate 92 f.
A magnified, perspective exploded view of the outlet valve 108 f is depicted in FIG. 17A. The outlet valve 108 f includes a steel valve disk 140 having multiple radially-extending guides 142 and reliefs 144 and a center positioned spring seat 146 for engaging and positioning a valve spring 148. The valve spring 148 is positioned between the valve disk 140 and a steel spring retainer 150 having a plurality of air holes 152 arranged in a circular pattern and extending between the major planar surfaces through the spring retainer 150.
FIG. 17B depicts a magnified, side cross sectional view of the outlet valve 108 f positioned within the outlet hole 116 f of the cylinder valve plate 92 f between the compression cylinder 68 f and outlet chamber 114 f. As best understood by comparing FIGS. 17A and B, the spring retainer 150 is positioned above the valve spring 148 and locked in place with a steel snap ring 154. The valve spring 148 biases the valve disk 140, which is positioned to reciprocate vertically within the outlet hole 116 f, downward to a closed position against a steel valve seat 156 that extends from the cylinder valve plate 92 f into the outlet hole 116 f. The guides 142 center the valve disk 140 and the reliefs 144 provide spacing within the outlet hole 116 f to allow air to flow past the valve disk 140 when in the open position.
Referring again to FIG. 16, a similar metallic sealing check valve that is also substantially leak free is used as an inlet valve 86 f and positioned in the inlet hole 106 f of the cylinder valve plate 92 f. Consider the magnified cross sectional side view of the inlet valve 86 f in FIG. 18A and compare the outlet valve 108 f depicted in FIG. 17B. The inlet valve 86 f differs from the outlet valve 108 f in that the inlet valve 86 f includes a valve disk 140 f ′ that is biased upward to a closed position against the valve seat 156′. The inlet valve 86 f includes a steel valve disk 140′ with a center positioned spring seat 146′, a valve spring 148′, a steel spring retainer 150′ having a plurality of air holes 152′, spring retainer 150′, and a steel snap ring 154′ that are similar to those of the outlet valve 108 f but inverted to allow for the upward biasing of the valve disk 140′.
The compressor pump 66 f also includes an orifice 88 f positioned within an orifice tube 138 f leading directly from the compression cylinder 68 f to the environment surrounding the compressor pump 66 f.
Operation of the compressor pump 66 f is best understood by comparing FIGS. 16 with FIGS. 17A-C and 18A and B. During each intake stroke of the piston 70, the valve disk 140′ of the inlet valve 86 f moves downward against the bias of the valve spring 148′ from the closed position depicted in FIG. 18A to the open position depicted in FIG. 18B. The open position of the valve disk 140′ is also the open position of the inlet valve 86 f and results in the valve disk 140′ moving away from contact with the valve seat 156′. The open position of the inlet valve 86 f leaves a valve clearance 87 f between the valve disk 140′ and valve seat 156′ having a cross sectional size that is much larger than the orifice 88 f, resulting in a much larger amount of air being drawn into the compression cylinder 68 f through the inlet valve 86 f than through the orifice 88 f during the intake stroke. As air is drawn in from the cylinder inlet chamber 84 f through the inlet valve 86 f, it proceeds into the inlet hole 106 f along a path indicated with air flow arrows 158′ through the valve clearance 87 f′, around the reliefs 144′, and through air holes 152′ into the compression cylinder 68 f.
During each intake stroke, the valve disk 140 of the outlet valve 108 f remains in the closed position, as depicted in FIG. 17B, the valve disk 140 remaining in sealing contact with the valve seat 156. Both the valve seat 156 and valve disk 140 are typically constructed of steel. However, one or both of the valve seat 156 and valve disk 140 typically include a polished steel surface and also utilize oil carry over that may be present if the compressor system 64 f is a lubricated system. The mating shapes of the valve seat 156 and valve disk 140 can also enhance the sealing characteristics of the outlet valve 108 f. These features allow the outlet valve 108 f to be substantially leak free in the closed position, enabling the outlet valve 108 f to seal and prevent air pressure from the outlet chamber 83 f and discharge tube 126 f from flowing back into the compression cylinder 68 f during the intake stroke.
During each compression stroke of the piston 70, the valve disk 140′ of the inlet valve 8 f returns to the closed position under the combined force of air compression by the piston 70 and the bias of the valve spring 148′, as depicted in FIG. 18A. The closed position of the inlet valve 86 f results in the valve disk 140′ moving into contact with the valve seat 156′, preventing compressed air from flowing into the inlet chamber 84 f.
The compression forces of the piston 70 during the intake stroke also result in the valve disk 140 of the outlet valve 108 f moving against the bias of the valve spring 148, as depicted in FIG. 17B, the valve disk 140 moving upward away from sealing contact with the valve seat 156. The open position of the outlet valve 108 f also results in a valve clearance 87 f between the valve disk 140 and valve seat 156, having a cross sectional size that is much larger than the orifice 88 f. A much larger amount of air is therefore capable of exiting the compression cylinder 68 f through the outlet valve 108 f than through the orifice 88 f during the compression stroke stroke. As air from the compression cylinder 68 f enters the outlet valve 108 f, the air flow proceeds along a path through the outlet hole 116 f indicated with air flow arrows 158 through the valve clearance 87 f, around the reliefs 144′, and through the air holes 152 into the outlet chamber 114 f.
Those skilled in the art will recognize that the various features of this invention described above can be used in various combinations with other elements without departing from the scope of the invention. Thus, the appended claims are intended to be interpreted to cover such equivalent air compressor systems as do not depart from the spirit and scope of the invention.

Claims

1. A compressor head for a reciprocating air compressor, the air compressor having a compressor pump having a compression cylinder, the compression cylinder having a piston positioned to reciprocate with intake and compression strokes within the compression cylinder, the compressor head comprising:

an inlet valve, said inlet valve having an open position and a closed position, said inlet valve having a valve clearance when said inlet valve is in said open position, said inlet valve moving to said open position and allowing air to enter the compression cylinder through said valve clearance during intake strokes of the piston, said inlet valve moving to said closed position and preventing air from exiting the compression cylinder through the valve clearance during compression strokes of the piston; and

an orifice having a cross sectional size that is significantly smaller than the effective area of said valve clearance of said inlet valve, said orifice positioned to allow air to enter the compression cylinder during intake strokes of the piston and to allow air to exit the compression cylinder during compression strokes of the piston.

2. The compressor head for a reciprocating air compressor of claim 1, said compressor head further comprising an outlet valve having an open position and a closed position, said outlet valve moving to said open position and allowing air to exit said compression cylinder during compression strokes of said piston, said outlet valve moving to said closed position and preventing air from entering said compression cylinder through said outlet valve during intake strokes of said piston, said outlet valve moving to said closed position and preventing air from entering said compression cylinder through said outlet valve when said piston is not reciprocating in said compression cylinder, said outlet valve being substantially leak free when in said closed position.

3. The compressor head for a reciprocating air compressor of claim 1, said compressor head further comprising an outlet valve having an open position and a closed position, said outlet valve moving to said open position and allowing air to exit said compression cylinder during compression strokes of said piston, said outlet valve moving to said closed position and preventing air from entering said compression cylinder through said outlet valve during intake strokes of said piston, said outlet valve moving to said closed position and preventing air from entering said compression cylinder through said outlet valve when said piston is not reciprocating in said compression cylinder, said outlet valve being substantially leak free when in said closed position, said outlet valve comprising an elastomeric o-ring check valve.

4. The compressor head for a reciprocating air compressor of claim 1 further comprising:

an outlet valve that is an elastomeric o-ring check valve,

a hollow valve shaft, said valve shaft having a tapered portion, a non-tapered portion, an open top, and an inside surface;

a sealing ring having a closed position and an open position, said sealing ring being capable of reciprocating along said non-tapered portion of said valve shaft from said closed position and said open position;

an actuation ring positioned to reciprocate along said tapered portion of said valve shaft, said actuation ring biasing said sealing ring to said closed position; and

said open top of said valve shaft being positioned to allow air from the environment surrounding said cylinder arrangement to flow across and cool said inside surface of said valve shaft.

5. The compressor head for a reciprocating air compressor of claim 1 having an outlet valve comprising a spring-actuated elastomeric o-ring check valve.

6. The compressor head for a reciprocating air compressor of claim 1 having an outlet valve comprising a metallic sealing check valve.

7. The compressor head for a reciprocating air compressor of claim 1, said inlet valve comprising a reed valve.

8. The compressor head for a reciprocating air compressor of claim 1 having an outlet valve comprising a spring-actuated check valve.

9. The compressor head for a reciprocating air compressor of claim 1 further comprising an outlet valve, said outlet valve being capable of sealing and preventing air that has been compressed by said piston from flowing back through said outlet valve when said outlet valve is closed during intake strokes of said piston.

10. The compressor head for a reciprocating air compressor of claim 1 further comprising:

a cylinder valve plate, said inlet valve being positioned on said valve plate to allow air to pass through said valve plate into said compression cylinder during intake strokes of said piston, said orifice being positioned on said valve plate to allow air to pass through said valve plate to said compression cylinder during intake strokes of said piston and being positioned to allow air to exit said compression cylinder through said valve plate during compression strokes of said piston; and

an outlet valve positioned relative to said valve plate to allow air to exit from said compression cylinder through said valve plate during compression strokes of said piston.

11. The compressor head for a reciprocating air compressor of claim 1 further comprising:

a cylinder inlet chamber for receiving air from the environment surrounding said compressor pump and for providing air to said compression cylinder;

a cylinder outlet chamber for receiving air that has been compressed by said piston in said compression cylinder;

a cylinder valve plate positioned between said cylinder inlet chamber and said compression cylinder and between said compression cylinder and said cylinder outlet chamber;

said inlet valve being positioned on said valve plate to allow air to pass from said cylinder inlet chamber into said compression cylinder during intake strokes of said piston;

said orifice being positioned to allow air to pass through said valve plate from said cylinder inlet chamber to said compression cylinder during intake strokes of said piston and positioned to allow air to pass through said valve plate from said compression cylinder to said cylinder inlet chamber during compression strokes of said piston; and

an outlet valve being positioned relative to said valve plate to allow air to pass from said compression cylinder to said cylinder outlet chamber during compression strokes of said piston,

12. The compressor head for a reciprocating air compressor of claim 1 further comprising:

said orifice being positioned to allow air to flow from said cylinder inlet chamber to said compression cylinder during intake strokes of said piston; and

said orifice being positioned to allow air to flow from said compression cylinder to said cylinder inlet chamber during compression strokes of said piston.

13. The compressor head for a reciprocating air compressor of claim 1 further comprising:

said orifice extending from said cylinder inlet chamber to said compression cylinder;

14. The compressor head for a reciprocating air compressor of claim 1 further comprising:

said inlet valve comprising a reed valve; and

said orifice being positioned to extend through said reed valve to allow air to flow into said compression cylinder during intake strokes of said piston and to allow air to exit from said compression cylinder during compression strokes of said piston.

15. The compressor head for a reciprocating air compressor of claim 1 further comprising:

said orifice extending from said compression cylinder to the environment surrounding said compressor pump;

said orifice being positioned to allow air to flow from the environment surrounding said compressor pump to said compression cylinder during intake strokes of said piston; and

said orifice being positioned to allow air to flow from said compression cylinder to the environment surrounding said compressor pump during compression strokes of said piston.

16. The compressor head for a reciprocating air compressor of claim 1 further comprising:

said orifice including an orifice tube extending from said cylinder inlet chamber to the exterior of said compressor pump and to said compression cylinder;

17. The compressor bead for a reciprocating air compressor of claim 1 further comprising an outlet valve, a discharge tube, and an air reservoir, said outlet valve being positioned to prevent the loss of air pressure within said air reservoir and said discharge tube through said compressor pump when said piston is not reciprocating.

18. A compressor head for a reciprocating air compressor, the air compressor having a compressor pump having a compression cylinder, the compression cylinder having a piston positioned to reciprocate with intake and compression strokes within the compression cylinder, the compressor head comprising:

an air passage extending from upstream of said inlet valve to said compression cylinder, said air passage having a cross sectional size that is significantly smaller than the effective area of said valve clearance of said inlet valve, said air passage positioned to allow air to enter the compression cylinder during intake strokes of the piston and to allow air to exit the compression cylinder during compression strokes of the piston.

19. The compressor head for a reciprocating air compressor of claim 18, said air passage further comprising an orifice, said orifice having a cross sectional size that is significantly smaller than the effective area of said valve clearance of said inlet valve, said orifice positioned to allow air to enter the compression cylinder during intake strokes of the piston and to allow air to exit the compression cylinder during compression strokes of the piston.

20. The compressor head for a reciprocating air compressor of claim 18, said compressor head further comprising an outlet valve having an open position and a closed position, said outlet valve moving to said open position and allowing air to exit said compression cylinder during compression strokes of said piston, said outlet valve moving to said closed position and preventing air from entering said compression cylinder through said outlet valve during intake strokes of said piston, said outlet valve moving to said closed position and preventing air from entering said compression cylinder through said outlet valve when said piston is not reciprocating in said compression cylinder, said outlet valve being substantially leak free when in said closed position.

21. The compressor head for a reciprocating air compressor of claim 18, said compressor head further comprising an outlet valve having an open position and a closed position, said outlet valve moving to said open position and allowing air to exit said compression cylinder during compression strokes of said piston, said outlet valve moving to said closed position and preventing air from entering said compression cylinder through said outlet valve during intake strokes of said piston, said outlet valve moving to said closed position and preventing air from entering said compression cylinder through said outlet valve when said piston is not reciprocating in said compression cylinder, said outlet valve being substantially leak free when in said closed position, said outlet valve comprising an elastomeric o-ring check valve.

22. The compressor head for a reciprocating air compressor of claim 18 further comprising:

an outlet valve that is an elastomeric o-ring check valve,

23. The compressor head for a reciprocating air compressor of claim 18 having an outlet valve comprising a spring-actuated elastomeric o-ring check valve.

24. The compressor head for a reciprocating air compressor of claim 18 having an outlet valve comprising a metallic sealing check valve.

25. The compressor head for a reciprocating air compressor of claim 18, said inlet valve comprising a reed valve.

26. The compressor head for a reciprocating air compressor of claim 18 having an outlet valve comprising a spring-actuated check valve.

27. The compressor head for a reciprocating air compressor of claim 18 further comprising an outlet valve, said outlet valve being capable of sealing and preventing air that has been compressed by said piston from flowing back through said outlet valve when said outlet valve is closed during intake strokes of said piston.

28. The compressor head for a reciprocating air compressor of claim 18 further comprising:

a cylinder valve plate, said inlet valve being positioned on said valve plate to allow air to pass through said valve plate into said compression cylinder during intake strokes of said piston, said air passage being positioned on said valve plate to allow air to pass through said valve plate to said compression cylinder during intake strokes of said piston and being positioned to allow air to exit said compression cylinder through said valve plate during compression strokes of said piston; and

29. The compressor head for a reciprocating air compressor of claim 18 further comprising:

said air passage being positioned to allow air to pass through said valve plate from said cylinder inlet chamber to said compression cylinder during intake strokes of said piston and positioned to allow air to pass through said valve plate from said compression cylinder to said cylinder inlet chamber during compression strokes of said piston; and

an outlet valve being positioned relative to said valve plate to allow air to pass from said compression cylinder to said cylinder outlet chamber during compression strokes of said piston.

30. The compressor head for a reciprocating air compressor of claim 18 further comprising:

said air passage being positioned to allow air to flow from said cylinder inlet chamber to said compression cylinder during intake strokes of said piston; and

said air passage being positioned to allow air to flow from said compression cylinder to said cylinder inlet chamber during compression strokes of said piston.

31. The compressor head for a reciprocating air compressor of claim 18 further comprising.

said air passage extending from said cylinder inlet chamber to said compression cylinder;

32. The compressor head for a reciprocating air compressor of claim 18 further comprising:

said inlet valve comprising a reed valve; and

said air passage being positioned to extend through said reed valve to allow air to flow into said compression cylinder during intake strokes of said piston and to allow air to exit from said compression cylinder during compression strokes of said piston.

33. The compressor head for a reciprocating air compressor of claim 18 further comprising;

said air passage extending from said compression cylinder to the upstream environment surrounding said compressor pump;

said air passage being positioned to allow air to flow from the upstream environment surrounding said compressor pump to said compression cylinder during intake strokes of said piston; and

said air passage being positioned to allow air to flow from said compression cylinder to the upstream environment surrounding said compressor pump during compression strokes of said piston.

34. The compressor head for a reciprocating air compressor of claim 18 further comprising:

said air passage comprising an orifice tube extending from said cylinder inlet chamber to the exterior of said compressor pump and to said compression cylinder;

35. The compressor head for a reciprocating air compressor of claim 18 further comprising an outlet valve, a discharge tube, and an air reservoir, said outlet valve being positioned to prevent the loss of air pressure within said air reservoir and said discharge tube through said compressor pump when said piston is not reciprocating.

36. A cylinder arrangement for a reciprocating air compressor comprising:

a compressor pump having a compression cylinder, said compression cylinder having a piston positioned to reciprocate with intake and compression strokes within said compression cylinder;

an inlet valve, said inlet valve having an open position and a closed position, said inlet valve having a valve clearance when said inlet valve is in said open position, said inlet valve moving to said open position and allowing air to enter said compression cylinder through said valve clearance during intake strokes of said piston, said inlet valve moving to said closed position and preventing air from exiting said compression cylinder through said valve clearance during compression strokes of said piston;

an orifice having a minimum cross sectional size that is smaller than said valve clearance of said inlet valve, said orifice allowing air to enter said compression cylinder during intake strokes of said piston, said orifice allowing air to exit said compression cylinder during compression strokes of said piston;

a discharge tube and an air reservoir, said discharge tube allowing air to flow from said compressor pump to said air reservoir; and

an outlet valve having an open position and a closed position, said outlet valve moving to said open position and allowing air to exit said compression cylinder and enter said discharge tube during compression strokes of said piston, said outlet valve moving to said closed position and preventing air from entering said compression cylinder through said outlet valve during intake strokes of said piston, said outlet valve moving to said closed position and preventing air from said discharge tube and from said air reservoir from entering said compression cylinder through said outlet valve when said piston is not reciprocating in said compression cylinder, said outlet valve being substantially leak free when in said closed position.

37. The cylinder arrangement for a reciprocating air compressor of claim 36, said outlet valve comprising an elastomeric o-ring check valve.

38. The cylinder arrangement for a reciprocating air compressor of claim 36, said outlet valve being an elastomeric o-ring check valve further comprising:

39. The cylinder arrangement for a reciprocating air compressor of claim 36, said outlet valve comprising a spring-actuated elastomeric o-ring check valve.

40. The cylinder arrangement for a reciprocating air compressor of claim 36, said outlet valve comprising a metallic sealing check valve.

41. The cylinder arrangement for a reciprocating air compressor of claim 36, said inlet valve comprising a reed valve.

42. The cylinder arrangement for a reciprocating air compressor of claim 36, said outlet valve comprising a spring-actuated check valve.

43. The cylinder arrangement for a reciprocating air compressor of claim 36, said outlet valve being capable of sealing and maintaining air pressure within said discharge tube to prevent the escape of air from the air reservoir to the environment surrounding said cylinder arrangement when said piston is not reciprocating within said compression cylinder.

44. The cylinder arrangement for a reciprocating air compressor of claim 36, said outlet valve being capable of sealing and preventing air that has been compressed by said piston from flowing back through said outlet valve when said outlet valve is closed during intake strokes of said piston.

45. The cylinder arrangement for a reciprocating air compressor of claim 36 further comprising a cylinder valve plate, said inlet valve being positioned on said valve plate to allow air to pass through said valve plate into said compression cylinder during intake strokes of said piston, said orifice being positioned on said valve plate to allow air to pass through said valve plate to said compression cylinder during intake strokes of said piston and being positioned to allow air to exit said compression cylinder through said valve plate during compression strokes of said piston, said outlet valve being positioned relative to said valve plate to allow air to exit from said compression cylinder through said valve plate during compression strokes of said piston.

46. The cylinder arrangement for a reciprocating air compressor of claim 36 further comprising:

a cylinder outlet chamber for receiving air that has been compressed by said piston in said compression cylinder:

said outlet valve being positioned relative to said valve plate to allow air to pass from said compression cylinder to said cylinder outlet chamber during compression strokes of said piston.

47. The cylinder arrangement for a reciprocating air compressor of claim 36 further comprising:

48. The cylinder arrangement for a reciprocating air compressor of claim 36 further comprising:

49. The cylinder arrangement for a reciprocating air compressor of claim 36 further comprising:

said inlet valve comprising a reed valve; and

50. The cylinder arrangement for a reciprocating air compressor of claim 36 further comprising:

51. The cylinder arrangement for a reciprocating air compressor of claim 36 further comprising:

52. The cylinder arrangement for a reciprocating air compressor of claim 36, said outlet valve being positioned to prevent the loss of air pressure within said air reservoir and said discharge tube through said compressor pump when said piston is not reciprocating.

53. A compressor pump for a reciprocating air compressor comprising:

a compression cylinder, said compression cylinder having a piston positioned to reciprocate with intake and compression strokes within said compression cylinder;

an orifice having a minimum cross sectional size that is smaller than said valve clearance of said inlet valve, said orifice allowing air to enter said compression cylinder during intake strokes of said piston, said orifice allowing air to exit said compression cylinder during compression strokes of said piston; and

an outlet valve having an open position and a closed position, said outlet valve moving to said open position and allowing air to exit said compression cylinder during compression strokes of said piston, said outlet valve moving to said closed position and preventing air from entering said compression cylinder through said outlet valve during intake strokes of said piston, said outlet valve moving to said closed position and preventing air from entering said compression cylinder through said outlet valve when said piston is not reciprocating in said compression cylinder, said outlet valve being substantially leak free when in said closed position.

54. The compressor pump of claim 53, said outlet valve comprising an elastomeric o-ring check valve.

55. The compressor pump of claim 53, said outlet valve being an elastomeric o-ring check valve further comprising:

56. The compressor pump of claim 53, said outlet valve comprising a spring-actuated elastomeric o-ring check valve.

57. The compressor pump of claim 53, said outlet valve comprising a metallic scaling check valve.

58. The compressor pump of claim 53, said inlet valve comprising a reed valve.

59. The compressor pump of claim 53, said outlet valve comprising a spring-actuated check valve.

60. The compressor pump of claim 53, said outlet valve being capable of sealing and maintaining air pressure within said discharge tube to prevent the escape of air from the air reservoir to the environment surrounding said compressor pump when said piston is not reciprocating within said compression cylinder.

61. The compressor pump of claim 53, said outlet valve being capable of sealing and preventing air that has been compressed by said piston from flowing back through said outlet valve when said outlet valve is closed during intake strokes of said piston.

62. The compressor pump of claim 53 further comprising a cylinder valve plate, said inlet valve being positioned on said valve plate to allow air to pass through said valve plate into said compression cylinder during intake strokes of said piston, said orifice being positioned on said valve plate to allow air to pass through said valve plate to said compression cylinder during intake strokes of said piston and being positioned to allow air to exit said compression cylinder through said valve plate during compression strokes of said piston, said outlet valve being positioned relative to said valve plate to allow air to exit from said compression cylinder through said valve plate during compression strokes of said piston.

63. The compressor pump of claim 53 further comprising:

said outlet valve being positioned relative to said valve plate to allow air to pass from said compression cylinder to said cylinder outlet chamber through said valve plate during compression strokes of said piston.

64. The compressor pump of claim 53 further comprising:

65. The compressor pump of claim 53 further comprising:

66. The compressor pump of claim 53 further comprising:

said inlet valve comprising a reed valve; and

67. The compressor pump of claim 53 further comprising:

68. The compressor pump of claim 53 further comprising:

69. A cylinder valve plate for a reciprocating air compressor having an air compressor pump, the compressor pump having a compression cylinder and a piston positioned to reciprocate with intake and compression strokes within the compression cylinder, said cylinder valve plate comprising:

a valve plate body for mounting within the compressor pump;

an inlet valve positioned on said valve plate body, said inlet valve having an open position and a closed position, said inlet valve having a valve clearance when said inlet valve is in said open position, said inlet valve moving to said open position and allowing air to enter the compression cylinder through said valve clearance during intake strokes of the piston, said inlet valve moving to said closed position and preventing air from exiting the compression cylinder through said valve clearance during compression strokes of the piston;

an orifice having a minimum cross sectional size that is smaller than said valve clearance of said inlet valve, said orifice allowing air to enter the compression cylinder during intake strokes of the piston, said orifice allowing air to exit the compression cylinder during compression strokes of the piston; and

an outlet valve positioned relative to said valve plate body, said outlet valve having an open position and a closed position, said outlet valve moving to said open position and allowing air to exit the compression cylinder during compression strokes of the piston, said outlet valve moving to said closed position and preventing air from entering the compression cylinder through said outlet valve during intake strokes of the piston, said outlet valve moving to said closed position and preventing air from entering the compression cylinder through said outlet valve when the piston is not reciprocating in the compression cylinder, said outlet valve being substantially leak free when in said closed position.

70. The cylinder valve plate of claim 69, said outlet valve comprising an elastomeric o-ring check valve.

71. The cylinder valve plate of claim 69, said outlet valve being an elastomeric o-ring check valve further comprising:

a scaling ring having a closed position and an open position, said sealing ring being capable of reciprocating along said non-tapered portion of said valve shaft from said closed position and said open position;

72. The cylinder valve plate of claim 69, said outlet valve comprising a spring-actuated elastomeric o-ring check valve.

73. The cylinder valve plate of claim 69, said outlet valve comprising a metallic sealing check valve.

74. The cylinder valve plate of claim 69, said inlet valve comprising a reed valve.

75. The cylinder valve plate of claim 69, said outlet valve comprising a spring-actuated check valve.

76. The cylinder valve plate of claim 69, said outlet valve being capable of sealing and maintaining air pressure within said discharge tube to prevent the escape of air from the air reservoir to the environment surrounding the reciprocating air compressor when said piston is not reciprocating within said compression cylinder.

77. The cylinder valve plate of claim 69, said outlet valve being capable of sealing and preventing air that has been compressed by said piston from flowing back through said outlet valve when said outlet valve is closed during intake strokes of said piston.

78. The cylinder valve plate of claim 69, the compressor pump having a cylinder inlet chamber for receiving air from the environment surrounding the compressor pump and for providing air to the compression cylinder, said orifice being positioned to allow air to flow from the cylinder inlet chamber to the compression cylinder during intake strokes of the piston, said orifice being positioned to allow air to flow from the compression cylinder to the cylinder inlet chamber during compression strokes of the piston.

79. The cylinder valve plate of claim 69, the compressor pump having a cylinder inlet chamber for receiving air from the environment surrounding the compressor pump and for providing air to the compression cylinder, said orifice extending from the cylinder inlet chamber to the compression cylinder, said orifice being positioned to allow air to flow from the cylinder inlet chamber to the compression cylinder during intake strokes of the piston, said orifice being positioned to allow air to flow from the compression cylinder to the cylinder inlet chamber during compression strokes of the piston.

80. The cylinder valve plate of claim 69, said inlet valve comprising a reed valve, said orifice being positioned to extend through said reed valve to allow air to flow into the compression cylinder during intake strokes of the piston and to allow air to exit from the compression cylinder during compression strokes of the piston.

81. The cylinder valve plate of claim 69 further comprising:

said orifice extending from the compression cylinder to the environment surrounding the compressor pump;

said orifice being positioned to allow air to flow from the environment surrounding the compressor pump to the compression cylinder during intake strokes of the piston; and

said orifice being positioned to allow air to flow from the compression cylinder to the environment surrounding the compressor pump during compression strokes of the piston.

82. The cylinder valve plate of claim 69, the compressor pump having a cylinder inlet chamber for receiving air from the environment surrounding the compressor pump and for providing air to the compression cylinder;

said orifice including an orifice tube extending from the cylinder inlet chamber to the exterior of the compressor pump and to the compression cylinder;

said orifice being positioned to allow air to flow from the cylinder inlet chamber to the compression cylinder during intake strokes of the piston; and

said orifice being positioned to allow air to flow from the compression cylinder to the cylinder inlet chamber during compression strokes of the piston.

83. A compressor pump for a reciprocating air compressor comprising,

an outlet valve positioned between said compression cylinder and said discharge tube, said outlet valve being the only valve positioned between said compression cylinder and said discharge tube, said outlet valve having an open position and a closed position, said outlet valve moving to said open position and allowing air to exit said compression cylinder during compression strokes of said piston, said outlet valve moving to said closed position and preventing air from entering said compression cylinder through said outlet valve during intake strokes of said piston, said outlet valve moving to said closed position and preventing air from entering said compression cylinder through said outlet valve when said piston is not reciprocating in said compression cylinder, said outlet valve being substantially leak free when in said closed position.

84. The compressor pump of claim 83, said outlet valve comprising an elastomeric o-ring check valve.

85. The compressor pump of claim 83, said outlet valve being an elastomeric o-ring check valve further comprising:

86. The compressor pump of claim 83, said outlet valve comprising a spring-actuated elastomeric o-ring check valve.

87. The compressor pump of claim 83, said outlet valve comprising a metallic sealing check valve.

88. The compressor pump of claim 83, said inlet valve comprising a reed valve.

89. The compressor pump of claim 83, said outlet valve comprising a spring-actuated check valve.

90. The compressor pump of claim 83, said outlet valve being capable of sealing and maintaining air pressure within said discharge tube to prevent the escape of air from the air reservoir to the environment surrounding said compressor pump when said piston is not reciprocating within said compression cylinder.

91. The compressor pump of claim 83, said outlet valve being capable of sealing and preventing air that has been compressed by said piston from flowing back through said outlet valve when said outlet valve is closed during intake strokes of said piston.

92. The compressor pump of claim 83 further comprising a cylinder valve plate, said inlet valve being positioned on said valve plate to allow air to pass through said valve plate into said compression cylinder during intake strokes of said piston, said orifice being positioned on said valve plate to allow air to pass through said valve plate to said compression cylinder during intake strokes of said piston and being positioned to allow air to exit said compression cylinder through said valve plate during compression strokes of said piston, said outlet valve being positioned relative to said valve plate to allow air to exit from said compression cylinder through said valve plate during compression strokes of said piston.

93. The compressor pump of claim 83 further comprising:

said inlet valve being positioned on said valve plate to allow air to pass from said cylinder inlet chamber into said compression cylinder during intake strokes of said piston,

94. The compressor pump of claim 83 further comprising:

95. The compressor pump of claim 83 further comprising:

96. The compressor pump of claim 83 further comprising:

said inlet valve comprising a reed valve; and

97. The compressor pump of claim 83 further comprising;

98. The compressor pump of claim 83 further comprising:

99. A reciprocating air compressor system comprising:

an engine for reciprocating said piston within said compression cylinder;

an outlet valve having an open position and a closed position, said outlet valve moving to said open position and allowing air to exit said compression cylinder and enter said discharge tube through said outlet valve during compression strokes of said piston, said outlet valve moving to said closed position and preventing air from entering said compression cylinder through said outlet valve during intake strokes of said piston, said outlet valve moving to said closed position and preventing air from said discharge tube and from said air reservoir from entering said compression cylinder through said outlet valve when said piston is not reciprocating in said compression cylinder, said outlet valve being substantially leak free when in said closed position.

100. The reciprocating air compressor system of claim 99 further comprising a pressure switch for operating said motor, said pressure switch being positioned to cause said motor to reciprocate said piston and cause said air compressor system to compress air when air pressure in said air reservoir is below a predetermined minimum level, said pressure switch being positioned to cause said motor to stop reciprocating said piston and cause said air compressor system to stop compressing air when air pressure in said air reservoir is above predetermined maximum level.

101. The reciprocating air compressor system of claim 99, said outlet valve comprising an elastomeric o-ring check valve.

102. The reciprocating air compressor system of claim 99, said outlet valve being an elastomeric o-ring check valve further comprising:

103. The reciprocating air compressor system of claim 99, said outlet valve comprising a spring-actuated elastomeric o-ring check valve.

104. The reciprocating air compressor system of claim 99, said outlet valve comprising a metallic sealing check valve.

105. The reciprocating air compressor system of claim 99, said outlet valve being capable of sealing and maintaining air pressure within said discharge tube to prevent the escape of air from the air reservoir to the environment surrounding said air compressor system when said piston is not reciprocating within said compression cylinder.

106. The reciprocating air compressor system of claim 99, said outlet valve being capable of sealing and preventing air that has been compressed by said piston from flowing back through said outlet valve when said outlet valve is closed during intake strokes of said piston.

107. The reciprocating air compressor system of claim 99, said inlet valve comprising a reed valve.

108. The reciprocating air compressor system of claim 99, said outlet valve comprising a spring-actuated check valve.

109. The reciprocating air compressor system of claim 99 further comprising a cylinder valve plate, said inlet valve being positioned on said valve plate to allow air to pass through said valve plate into said compression cylinder during intake strokes of said piston, said orifice being positioned on said valve plate to allow air to pass through said valve plate to said compression cylinder during intake strokes of said piston and being positioned to allow air to exit said compression cylinder through said valve plate during compression strokes of said piston, said outlet valve being positioned on said valve plate to allow air to exit from said compression cylinder during compression strokes of said piston.

110. The reciprocating air compressor system of claim 99 further comprising:

111. The reciprocating air compressor system of claim 99 further comprising:

112. The reciprocating air compressor system of claim 99 further comprising:

113. The reciprocating air compressor system of claim 99 further comprising:

said inlet valve comprising a reed valve; and

114. The reciprocating air compressor system of claim 99 further comprising:

115. The reciprocating air compressor system of claim 99 further comprising:

116. The reciprocating air compressor system of claim 99, said outlet valve being positioned to prevent the loss of air pressure within said air reservoir and said discharge tube through said compressor pump when said piston is not reciprocating.

117. A cylinder arrangement for a reciprocating air compressor comprising:

an inlet valve comprising a reed valve, said inlet valve having an open position and a closed position, said inlet valve having a valve clearance when said inlet valve is in said open position, said inlet valve moving to said open position and allowing air to enter said compression cylinder through said valve clearance during intake strokes of said piston, said inlet valve moving to said closed position and preventing air from exiting said compression cylinder through said valve clearance during compression strokes of said piston;

a discharge tube and an air reservoir, said discharge tube allowing air to flow from said compressor pump to said air reservoir:

an outlet valve comprising a spring-actuated elastomeric check valve, said outlet valve having an open position and a closed position, said outlet valve moving to said open position and allowing air to exit said compression cylinder and enter said discharge tube during compression strokes of said piston, said outlet valve moving to said closed position and preventing air from entering said compression cylinder through said outlet valve during intake strokes of said piston, said outlet valve moving to said closed position and preventing air from said discharge tube and from said air reservoir from entering said compression cylinder through said outlet valve when said piston is not reciprocating in said compression cylinder, said outlet valve being substantially leak free when in said closed position; and

a cylinder valve plate, said inlet valve being positioned on said valve plate to allow air to pass through said valve plate into said compression cylinder during intake strokes of said piston, said orifice being positioned on said valve plate to allow air to pass through said valve plate to said compression cylinder during intake strokes of said piston and being positioned to allow air to exit said compression cylinder through said valve plate during compression strokes of said piston, said outlet valve being positioned relative to said valve plate to allow air to exit from said compression cylinder through said valve plate during compression strokes of said piston.

118. A cylinder arrangement for a reciprocating air compressor comprising:

a cylinder inlet chamber for receiving air from the environment surrounding said compressor pump and for providing air to said compressor cylinder;

an inlet valve comprising a reed valve, said inlet valve having an open position and a closed position, said inlet valve having a valve clearance when said inlet valve is in said open position, said inlet valve moving to said open position and allowing air to enter said compression cylinder from said cylinder inlet chamber through said valve clearance during intake strokes of said piston, said inlet valve moving to said closed position and preventing air from exiting said compression cylinder through said valve clearance during compression strokes of said piston;

a discharge tube and an air reservoir, said discharge tube allowing air to flow from said compressor pump to said air reservoir;

an outlet valve comprising a spring-actuated elastomeric check valve, said outlet valve having an open position and a closed position, said outlet valve moving to said open position and allowing air to exit said compression cylinder and enter said cylinder outlet chamber and said discharge tube during compression strokes of said piston, said outlet valve moving to said closed position and preventing air from entering said compression cylinder through said outlet valve during intake strokes of said piston, said outlet valve moving to said closed position and preventing air from said cylinder outlet chamber, from said discharge tube and from said air reservoir from entering said compression cylinder through said outlet valve when said piston is not reciprocating in said compression cylinder, said outlet valve being substantially leak free when in said closed position; and

119. A cylinder arrangement for a reciprocating air compressor comprising:

an outlet valve comprising a spring-actuated elastomeric check valve, said outlet valve having a hollow valve shaft, said valve shaft having a tapered portion, a non-tapered portion, an open top, and an inside surface, said outlet valve having a sealing ring having a closed position and an open position, said sealing ring being capable of reciprocating along said non-tapered portion of said valve shaft from said closed position and said open position, said outlet valve having an actuation ring positioned to reciprocate along said tapered portion of said valve shaft, said actuation ring biasing said sealing ring to said closed position, said open top of said valve shaft being positioned to allow air from the environment surrounding said cylinder arrangement to flow across and cool said inside surface of said valve shaft;

said sealing ring moving to said open position and allowing air to exit said compression cylinder and enter said discharge tube during compression strokes of said piston, said actuation ring moving said sealing ring to said closed position and preventing air from entering said compression cylinder through said outlet valve during intake strokes of said piston, said actuation ring moving said sealing ring to said closed position and preventing air from said discharge tube and from said air reservoir from entering said compression cylinder through said outlet valve when said piston is not reciprocating in said compression cylinder, said sealing ring being substantially leak free when in said closed position; and