Compressor valve

A compressor valve with annular valve members or rings instead of the usual spring-urged engagement of the rings with the valve seat, the rings are drawn into engagement with the seat by air or other gas passing through the valve in a direction reverse to that opening the valve. Thus, on reversal of the flow, the rings are virtually instantly brought into engagement with the seat without the need for springs bringing the valve rings into closed state. Both faces of the valve rings are identical. When one face is worn, the rings can be turned over to utilize the second valve face. The advance is in simplified structure, increased reliability and in longer operation life of the valve rings.

THE FIELD OF INVENTION 
The present invention relates to compressor valves sometimes also referred 
to as "plate valves". The valves of this type are associated with 
compressors or vacuum pumps, for instance with piston-type compressors 
wherein a piston reciprocates within a cylinder to draw air or other 
gaseous substance into the cylinder and to then discharge same in a 
compressed state to a suitable means for storage of the compressed gaseous 
medium. The compressors of this type must be provided at least with one 
intake valve and one discharge valve. The valves can also be referred to 
as "automatic one-way valves" as distinguished from the mechanically 
actuated type. That is to say, the valves are designed to allow the 
passage of the gaseous medium from one end of the valve to the other but 
to close automatically when the direction of flow of the gaseous medium is 
reversed. 
Thus, if an intake valve is associated with a respective piston compressor, 
it allows passage of the respective gaseous medium in a direction towards 
the cylinder. The direction can also be referred to in functional terms as 
being the direction of movement of the piston as it moves on intake of the 
gaseous medium towards its bottom dead centre. 
When the piston reaches its bottom dead centre, its movement becomes 
reversed with the result that the gaseous medium previously drawn into the 
cylinder by the piston now becomes compressed and discharged from the 
cylinder. The intake valve now must close while the discharge valve (which 
had been closed during the suction step of the compressor) now opens 
allowing the discharge of the gaseous medium either to the atmosphere or 
to a suitable storage means, depending on the particular application of 
the compressor. 
Thus, the two valves alternate their operational stage in accordance with 
the instant movement of the piston of the cylinder. 
There may be other applications for this type of valve. For convenience, 
however, the valves described hereinafter will be referred to as 
"compressor valves" since they are predominantly used in the field of the 
compressors.

DESCRIPTION OF PRIOR ART 
Turning firstly to FIGS. 1 and 2 of the accompanying drawings, and in 
particular to FIG. 1, a typical compressor valve of prior art is comprised 
of a disc-shaped valve seat 10 and a disc-shaped valve guard 11, the two 
being arranged to be firmly secured to each other to form a disc-shaped 
body of the valve. The inner faces of the valve seat 10 and valve guard 11 
define therebetween a valve chamber which houses valves or valve plates 
12, 13 and 14 and the spring assembly associated therewith and formed by a 
plurality of buttons 15 operatively associated with the valve plate 12 
having the largest diameter. Buttons 16 are similarly arranged to abut 
upon the intermediate valve plate 13 and the innermost buttons 17 are 
disposed underneath and in engagement with the valve plate 14 having the 
smallest diameter. There are only 3 buttons 18, whereas the number of the 
remaining buttons 15, 17, is 6. 
Each of the buttons 15, 16, and 17 is disposed on top of a coil spring such 
as coil springs 18, 19 and 20, respectively. 
The valve guard 11 has a set of 3 concentric support surfaces 21, 22 and 23 
which are all of annular configuration complementary with the annular 
shape of the valve plates 12, 13 and 14, respectively. 
The grooves between the supporting surfaces 21, 22 and 23 are designated 
with reference numerals 24, and 25, the latter being the slot having the 
smaller diameter. At the downwardly facing axial end of the valve guard 
11, the face not being visible in FIG. 1, a set of radial ribs holds the 
annular ribs forming the support surfaces 21, 22, 23 in a concentric 
arrangement to thus maintain uniform width of each of the grooves 24, 25. 
The valve seat 10 is provided with a total of 3 annular rows of circular 
passages. The outermost row of passages 26 has the same pitch diameter as 
the medium diameter of the valve plate 12. The diameter of the passages 26 
is smaller than the width of the associated valve plate 12, the last 
mentioned width being generally identical with the width of the 
corresponding supporting surface 21 in the valve guard 11. The remaining 
rows of openings 27 and 28 are similarly disposed on pitch circles 
corresponding in size to the valve plates 12, 13 and 14. 
It will be appreciated from FIG. 1 that, on assembly, the annular spaces 
between the respective rows of passages 26, 27 and 28 are disposed 
directly above the grooves 24 and 25. 
Turning back to the valve guard 11, it will be observed that it also has 
machined in it a number of cylindric openings such as cylindric openings 
29, each of which provides a seat for the respective one of the springs 
18, 19 and 20. The threaded stem 30 protruding from the top surface of the 
valve guard 11 is arranged to engage the thread in a threaded central 
opening 31 for suitable securement of the valve seat 10 to the valve guard 
11 with the described parts disposed within the valve chamber. 
The arrangement of FIG. 1 has several drawbacks. In particular, it is 
relatively expensive to produce due to a relatively large number of parts 
required. Furthermore, springs such as springs 18, 19 or 20 have the 
tendency to break. The buttons such as buttons 15, 16 and 18 present 
further manufacturing expense. In order to assure a good sealing effect, 
the valve plates 12, 13 and 14 which are made both from metallic and 
non-metallic materials must be accurately dimensioned in order to 
effectively seal the porting of the valve. Broken springs give rise to 
serious damages to the accurately machined interior of the valve chamber 
thus often impairing the operation of the valve and sometimes even 
rendering the valve completely inoperative. 
The embodiment of prior art shown in FIG. 2 presents certain improvement 
over what is shown in FIG. 1. A number of the parts of the arrangement in 
FIG. 2 corresponds to that of FIG. 1 and is therefore referred to with the 
same reference numerals indexed with "a". Thus, there is a valve seat 1Oa, 
a valve guard 11a, a number of passages 26a, 27a and 28a and, finally, a 
threaded stem 30a received in a central opening 31a. The latter two 
elements correspond in function to the stem 30 and to the central opening 
31 of the embodiment of FIG. 1, even though their position relative to the 
valve seat 1Oa and the valve guard 11a is reversed. 
Instead of flat valve plates 12, 13 and 14 shown in FIG. 1, the embodiment 
of FIG. 2 has a set of 3 valve rings 12a, 13a and 14a. The top surface of 
the valve rings 12a, 13a and 14a is not flat as in the embodiment of FIG. 
1. Instead, it is bevelled to form two conical surfaces, one having its 
apex above and the other below the respective ring. The two conical 
surfaces define a generally centrally disposed ridge. The peripheral 
grooves machined in the valve seat 10a and receiving the respective rings 
12a, 13a and 14a are provided with correspondingly shaped seats at the 
lowermost end of each of the peripheral grooves. In the representation of 
FIG. 2, of course, all of the peripheral grooves in valve seat 1Oa 
coincide with the respective passages 26a, 27a and 28a. 
The improvement of the arrangement of FIG. 2 over that of FIG. 1 is seen in 
the omission of the buttons 15, 16 and 18 and also in the provision of the 
bevelled surfaces much in the fashion of the bevelled closing surfaces of 
a combustion engine valve. The drawback is in that the arrangement still 
requires a large number of springs 18a, 19a and 20a having the tendency to 
break as referred to above. The valve rings 12a, 13a and 14a have a 
relatively short operational period and require frequent replacement as 
the section of their surfaces contacting the respective seating surfaces 
in the passage grooves of the valve seat 1Oa wear out. 
In operation, the valve allows the passage of air or other gas from top to 
bottom of FIG. 2. As the associated compressor draws air in (assuming that 
the shown valve is an intake valve), the pressure of the springs 18a, 19a 
and 20a is overcome and the air flows through passages 26a, 27a and 28a, 
then through the respective slots, along the top surface of now open valve 
rings 12a 13a and 14a and into the passages 24a and 25a forming functional 
counterparts of the grooves 24 and 25 of the embodiment of FIG. 1. On 
reversal of the gas flow, the springs 18a, 19a and 20a close the grooves 
in the valve seat 1Oa thus preventing passage of air upwards of FIG. 2. 
The common feature of most recent plate valves is that they all use some 
kind of spring means to retain the porting of the respective valve seats 
closed. This is so despite the fact that many valve constructions are 
known in which the medium flowing through the valve is utilized to move 
the valving member. Reference may be had in this context, only as an 
example, to U.S. Pat. No. 1,613,145 (Trump) issued Jan. 4, 1927, U.S. Pat. 
No. 2,333,288 (Benzel) issued Nov. 2, 1943; U.S. Pat. No. 3,412,563 (Sharp 
Jr.) issued Nov. 6, 1968 and in particular U.S. Pat. No. 3,158,175 
(Jaklitsch) issued Nov. 24, 1964, the latter reference relating to the 
compressor valves. The last mentioned reference shows that the abandonment 
the use springs has been subject to investigations in the field of 
compressor valves. Prior attempts to abandon the use of springs are 
described as having resulted in an untimely destruction of the valve 
rings. The reason for this seems to be the fact that a small delay in the 
disengagement of the valve ring from the damper in high speed compressor 
results in tremenduously high closing impact. The demolition of the valve 
rings is thus reported as being only a question of time. The solution in 
the Jaklitsch patent provides a valve in which the area of a damper member 
is reduced to a minimum so that the maximum surface area of the valve ring 
is exposed to the closing ring of the gaseous flow. The rings themselves 
are flat annular rings which are so designed as to provide a maximum 
surface area at the face of the ring turned away from the valve seat. The 
medium flowing through the valve is used to act predominantly on the axial 
surface of the ring with the resulting heavy impact of the valve ring on 
each closing of the valve. The idea of producing compressor valves with 
springless arrangement thus appears to have been subsequently abandoned, 
as shown by the most recent prior art arrangement described above. 
SUMMARY OF THE INVENTION 
It is an object of the present invention to provide further improvement in 
the art of compessor valves. 
In general terms, the present invention provides a compressor or plate 
valve comprising a valve seat and a valve guard, said valve seat and valve 
guard being fixedly secured to each other and defining therebetween a 
valve chamber housing valve means arranged to allow, in one terminal 
position thereof, passage of gaseous medium through the valve in a first 
direction, said first direction being oriented from the valve seat to the 
valve guard, and to prevent passage through said valve in a second 
direction opposite to the first direction, by sealingly engaging 
respective groove means in the surface of the valve seat facing the valve 
chamber, wherein the surface of said valve guard facing said valve chamber 
includes support means protruding into the valve chamber in register with 
the respective groove means, said support means freely supporting thereon 
the respective valve means in a position relative to the respective groove 
means such that the respective valve means is in register with the 
respective groove means and allows free passage of gaseous medium in the 
first direction; said valve guard forms passage means disposed to each 
side of each of the valve means; and said passage means in the valve 
guard, said support means and said annular valve means are so arranged and 
disposed as to cause displacement of the valve means from the state of 
being freely supported on said support means into a sealing engagement 
with the respective annular groove means when a predetermined gas flow 
oriented in the second direction passes through the valve. 
It is most preferred that the valve means and the groove means be of an 
annular configuration and that the said passage means formed in the guard 
be disposed to each radial side of a respective annular valve means. It is 
also preferred that the valve means be one or more valve rings. The valve 
rings are preferably symmetrical about a plane extending generally 
radially with respect to the ring and located centrally between the 
respective axial ends of the ring. The most preferred cross-sectional 
configuration of the valve ring is that of a V-shaped first end, a 
V-shaped second end and two straight sides (cylindric) disposed 
therebetween. The annular groove means can then be preferably provided 
such that their angular size corresponds to that of the axial faces of the 
rings. 
In another aspect, the present invention provides, for use in a compressor 
valve of the type including a valve seat and a valve guard, said seat and 
guard being fixedly secured to each other and defining therebetween a 
valve chamber, said valve seat having annular groove means in the surface 
of the valve seat facing the chamber: a valve ring comprising a first 
axial face section and a second axial face section, said axial face 
sections being symmetrical with respect to a plane perpendicular to the 
axis of the ring and disposed centrally with respect to the axial length 
of the ring, each of said face sections having a first portion inclined 
radially and axially inwardly and a second portion inclined radially 
outwardly and axially inwardly. 
Preferably, the face sections are each of a V-shaped cross-sectional 
configuration, said ring further comprising a cylindric central portion 
disposed between the axial face sections, whereby an annular ridge is 
formed at each axial end of the ring, the intermediate central portion 
thereof being generally cylindric. 
DESCRIPTION OF A PREFERRED EMBODIMENT 
Reference may now be had to FIGS. 3-10. The valve of the present invention 
is comprised of a valve seat 40 and of a valve guard 41. The valve seat 40 
and valve guard 41 are fixedly connected with each other by way of a 
securement member such as a threaded stem 42 whose head 43 is disposed 
centrally of the valve seat 40 at an exterior surface thereof. The 
threaded portion of the stem 43 is engaged in a thread 44 tapped in a 
cylindric central portion 45 of the valve guard 41. The top face of the 
central portion 45 is engaged within a recess provided at the bottom face 
of a central portion 46 of the valve seat 40. At the outer periphery of 
the valve seat 40 a shoulder section 47 is formed and the outer periphery 
of the valve guard 41 forms a complementary shoulder section 48 (FIG. 3). 
The mutually engaged portions of the shoulder sections 47 and 48 and of 
the central portions 45 and 46 maintain the valve seat and valve guard at 
a position wherein a valve chamber 49 is defined between the two parts. 
As in the case of the prior art valve, the guard seat 40 is provided at the 
top surface thereof with a number of concentric rows of circular passages. 
The passages of the outermost row are designated with reference numerals 
50, the next one with 51, then with 52 and the fourth row having the 
smallest diameter has passages 53. Each passage 50-53 communicates with a 
continuous annular groove at the end of the valve seat 40 facing the valve 
chamber 49. Thus, the series of passages 50 are maintained in 
communication with a groove 54, while the passages 51, 52 and 53 
communicate with grooves 55, 56 and 57, respectively. The lowermost edge 
of each of the grooves 54-57 is bevelled at 58, 59, 60 and 61. The bevel 
of the shown embodiment is approximately 45.degree.. 
Disposed in register with each of the grooves 54-57 is a respective valve 
ring 62, 63, 64 and 65. 
The valve rings 62-65 are made, in the preferred embodiment, from nylon 
reinforced by fiberglass fibres, the content of fiberglass fibres being 
approximately 30%. 
As regards the structural configuration of each of the rings, this is best 
seen from FIGS. 8-10. Each ring 65 has a first axial face section 66 and a 
second axial face section 67. The axial face section 66 and 67 are 
symmetrical with respect to a plane 68 which is perpendicular to the axis 
69 of the ring and is disposed centrally with respect to the axial length 
70 of the ring. Each of the face sections 66 and 67 has a first portion 71 
and 72 inclined radially and axially inwardly, and a second portion 73 and 
74. The portions 73 and 74 are at an angle with respect to the portions 71 
and 72, respectively, generally corresponding to the bevels 58-61 of the 
respective grooves 54-57. In other words, a V-shaped cross-sectional 
configuration is presented by each axial end of the ring. A cylindric 
central portion 75 is disposed between the axial face sections. Its width 
is designated with reference numeral 76. The angle of portions 74, 72 and 
73, 71 are the same. Accordingly, it is not of essence as to which face of 
the individual valve rings faces the valve seat 40. 
Each of the valve rings 62-65 rests on the top surface of an annular rib 
77, 78, 79 and 80. The width of each of the ribs 77-80 is equal, in the 
preferred embodiment, to the width 76 of the cylindric portion of the 
respective valve ring as shown in FIG. 9. Therefore, the width of the rib 
79 in FIG. 4 is referred to with the same reference numeral 76. Each of 
the ribs 77-78, 79, 80 has a V-shaped groove 81 in its top surface. The 
groove 81 being complementary with the V-shaped configuration of the 
respective valve ring. At the centre of each rib such as rib 80, the 
V-shaped groove is provided with a recess 82 which extends over the entire 
periphery and provides an air cushion for the respective valve ring. Each 
of the ribs 77-80 is further provided with a number of equidistantly 
spaced relieve passages 83 through which any impurities accumulated in the 
area of the respective V-shaped groove 81 can be removed. The concentric 
ribs 77-80 are so arranged that there is an annular channel to each side 
of each of the ribs 77-80. Thus, annular channels or passages 84, 85 is 
disposed one to each radial side of the rib 77. The next rib 78 is 
surrounded by the above passage 85 and by a next passage 86. Passages 87, 
88 are disposed one to each side of the rib 80. At a location flush with 
the lower outer surface of the valve guard 41, three ribs 89, 90, 91 (FIG. 
7) of rectangular cross-section are disposed. They serve the purpose of 
maintaining the ribs 77, 78, 79 and 80 at an equidistant spacing from each 
other and from the central portion 45 and to hold the entire guard 
together. 
Before proceeding with the description of operation of the valve according 
to the present invention, it is noteworthy that the drawing of the 
cross-sectional view of FIGS. 4, 5 and 6 are deliberately out of scale to 
facilitate the understanding of the operation. In particular, those 
skilled in the art know that the spacing between the respective rings 
62-65 and the bevels 58-61 is in fact substantially less than shown. This 
results in the upper ridge sections of the rings 62, 63, 64 and 65 being 
much deeper within the respective grooves 54, 55, 56 and 57 than shown in 
the drawing. This feature is important since it is advantageous that the 
valve rings 62, while being freely moveable and unattached to any part of 
the valve seat 40 or valve guard 41, they are still maintained in registry 
each with the respective groove so that the valve can be positioned in 
virtually any operative position, not necessarily in that shown in the 
drawing of FIG. 4. 
In operation and assuming that the valve of FIG. 4 is a suction or intake 
valve of a compressor, the open state of the valve is typical by the rings 
62, 63, 64 and 65 being remote from the respective seats or bevels 58-61. 
Air is drawn through the passages 50, 51, 52 and 53, through the 
associated grooves 54, 55, 56 and 57, by the respective valve rings 62-65 
and through the annular slots 84, 85, 86, 87 and 88 into the cylinder of 
the associated air compressor. The securement to the compressor per se is 
not shown and can be done by many different means known to those skilled 
in the art. As soon as the piston of the associated compressor reaches the 
lower dead point, the air previously drawn into the cylinder has the 
tendency to flow back through channels 84, 85, 86, 87 and 88. This flow 
virtually instantly lifts or displaces the valve rings 62, 63, 64 and 65 
into engagement with the seats or bevels 58, 59, 60 and 61, respectively, 
thus sealingly engaging same and preventing further flow of air through 
the valve in the reverse direction. The sequence of this operation is 
indicated diagramatically in FIGS. 5 and 6, of which FIG. 5 shows the 
intermediate stage very shortly after the reversal of the movement of the 
piston of an associated compressor while FIG. 6 shows the valve closed. 
As is well known, during the time period the valve is closed, another valve 
which is oriented in opposite fashion for discharge of the air from the 
compressor cylinder is open. As soon as the movement of the compressor 
piston is again reversed, the valve rings are drawn by the intake air back 
from the position of FIG. 6 over that of FIG. 5 to the arragement as seen 
from FIG. 4. The whole operation is now repeated. 
Those skilled in the art will immediately appreciate that many 
modifications may exist of the preferred arrangement as shown without 
departing from the present invention. For instance, the V-shaped 
configuration of the axial ends of the valve rings can be substituted by 
semi-cylindric shape which might be associated with a different kind of 
the seating 58, 59, 60 and 61 in the grooves of the valve seat 40. The 
number of valve rings is also optional. As a matter of fact, a valve 
having merely a single valve ring would also be operable and is within the 
scope of the present invention. The arrangement of the valve ring wherein 
the axial faces of same are a mirror image of each other is preferred 
because it enables reversal of the position of the individual valve rings 
when one end is worn. Thus, the life of the valve ring is in fact doubled 
in comparison with the valve rings of prior art shown in FIG. 2. It is 
believed that annular valve members (rings) are the best solution for the 
valve members which is not to say that the valve members could not have a 
different shape. For instance, the basic features of the present invention 
as far as the valve itself is concerned are also adaptable for use in 
valves having straight valve members somewhat similar to those shown in 
Canadian Pat. No. 1,069,019 (Kucenty), issued Jan. 1, 1980. In such case, 
of course, the valve rings 62-65 would have to be replaced by staight rods 
complimentary with remaining parts of the valve. 
The above are but a few examples of many other modifications of the present 
invention which may depart from the arrangement of the preferred 
embodiment described above, without departing from the present invention 
as recited in the accompanying claims.