U.S. patent number RE32,553 [Application Number 06/661,233] was granted by the patent office on 1987-12-08 for exhalation valve assembly.
Invention is credited to Clifford D. Bennett, Charles Odenthal.
United States Patent |
RE32,553 |
Bennett , et al. |
December 8, 1987 |
Exhalation valve assembly
Abstract
An exhalation valve assembly for use in a volume ventilator
circuit is disclosed. The valve assembly comprises a valve body
defining a chamber with a gas inlet conduit and a gas outlet
conduit, both in flow communication with the chamber. A diaphragm
extends across the chamber and selectively closes off the gas inlet
conduit. Upwardly extending strut members are disposed on an inside
surface of the valve body and are used to position a removable ring
member adjacent the diaphragm. The ring member is configured so as
to support a portion of the diaphragm over the chamber.
Inventors: |
Bennett; Clifford D. (Alta
Loma, CA), Odenthal; Charles (Upland, CA) |
Family
ID: |
27098270 |
Appl.
No.: |
06/661,233 |
Filed: |
October 15, 1984 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
Reissue of: |
964682 |
Nov 29, 1978 |
04241756 |
Dec 30, 1980 |
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Current U.S.
Class: |
137/271;
128/204.18; 128/205.24; 137/528; 137/859; 137/906; 137/908 |
Current CPC
Class: |
A61M
16/20 (20130101); A62B 18/10 (20130101); F16K
7/12 (20130101); A61M 16/206 (20140204); F16K
15/144 (20130101); Y10T 137/7895 (20150401); Y10T
137/5283 (20150401); Y10T 137/7904 (20150401) |
Current International
Class: |
A61M
16/20 (20060101); A62B 18/00 (20060101); A62B
18/10 (20060101); F16K 15/14 (20060101); F16K
7/12 (20060101); F16K 015/14 () |
Field of
Search: |
;137/102,269,271,496,528,859,908,906 ;251/61.1 ;92/6R,6D
;91/25 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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673007 |
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Dec 1964 |
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BE |
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422407 |
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Jan 1935 |
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GB |
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1007029 |
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Oct 1965 |
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GB |
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1014614 |
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Dec 1965 |
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GB |
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1260934 |
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Jan 1972 |
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GB |
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1264709 |
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Feb 1972 |
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GB |
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1462176 |
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Jan 1977 |
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GB |
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1553939 |
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Oct 1979 |
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GB |
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2015349 |
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Sep 1979 |
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GB |
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Primary Examiner: Schwadron; Martin P.
Assistant Examiner: Hepperle; Stephen M.
Attorney, Agent or Firm: Spensley Horn Jubas &
Lubitz
Claims
What is claimed:
1. A valve assembly for use in a volume ventilator, comprising:
(a) a valve body in part defining a pressure chamber.Iadd., said
valve body having an annular diaphragm seat.Iaddend.;
(b) a gas inlet conduit joined to and in flow communication with
said pressure chamber for directing a gas into said pressure
chamber, said gas inlet conduit forming a discharge port in said
pressure chamber;
(c) a gas outlet conduit joined to and in flow communication with
said pressure chamber for directing gas out of said pressure
chamber;
(d) diaphragm means removably disposed in and extending across said
valve body adjacent said discharge port for selectively closing off
said discharge port, said diaphragm means defining the remainder of
said pressure chamber;
(e) a removably disposed ring member extending into said pressure
chamber from a position adjacent the periphery thereof;
(f) a plurality of positioning members disposed on said body for
positioning said ring member in said pressure chamber such that
said ring member supports a predetermined portion of said diaphragm
means; and
(g) a cover having a gas inlet joined to said valve body and
extending across said diaphragm means on the opposite side thereof
from said pressure chamber.Iadd.;
(h) said cover having an annular lip and said diaphragm means is
sealed at its periphery between said annular lip and said diaphragm
seat; and
(i) the removably disposed ring member interfitting with a portion
of the diaphragm means and the valve body such that by removing
said ring member a valve assembly having a substantially different
valve area ratio may be achieved, permitting the valve assembly to
be used in different volume ventilator circuits.Iaddend..
2. A valve according to claim 1 wherein said chamber is cylindrical
and said discharge port is centrally disposed in said chamber.
3. A valve according to claim 1 wherein said positioning means
comprises a plurality of strut members.
4. A valve according to claim 1 wherein the ratio of the area of
said diaphragm means extending across said pressure chamber to the
area of said discharge port is approximately 2:1.
5. A valve according to claim 1 wherein said ring member supports a
portion of said diaphragm means such that the ratio of the
unsupported area of said diaphragm means extending across said
pressure chamber to the area of said discharge port is
approximately from 1:1 to 2:1.
6. A valve according to claim 1 wherein said positioning members
comprise a plurality of strut members located on said valve body,
and said ring member is removably disposed on said strut
members.
7. A valve according to claim 1 wherein said diaphragm means
includes a section which is positioned between said cover and said
ring member. .Iadd.
8. A valve assembly for use in a volume ventilator, comprising:
(a) a valve body in part defining a pressure chamber, said valve
body having an annular diaphragm seat;
(b) a gas inlet conduit joined to and in flow communication with
said pressure chamber for directing a gas into said pressure
chamber, said gas inlet conduit forming a discharge port in said
pressure chamber;
(c) a gas outlet conduit joined to and in flow communication with
said pressure chamber for directing gas out of said pressure
chamber;
(d) diaphragm means removably disposed in and extending across said
valve body adjacent said discharge port for selectively closing off
said discharge port, said diaphragm means defining the remainder of
said pressure chamber;
(e) a removably disposed ring member extending into said pressure
chamber from a position adjacent the periphery thereof;
(f) a plurality of positioning members disposed on said body for
positioning said ring member in said pressure chamber such that
said ring member in said pressure chamber such that said ring
member supports a predetermined portion of said diaphragm
means;
(g) said ring member being of substantial area, thus significantly
decreasing the effective area of the diaphragm means with respect
to the area of the discharge port, and in turn decreasing the valve
area ratio; and
(h) a cover having a gas inlet joined to said valve body and
extending across said diaphragm means on the opposite side thereof
from said pressure chamber, said cover having an annular lip and
said diaphragm means is sealed at its periphery between said
annular lip and said diaphragm seat; and
(i) by removing said ring member a valve assembly having a
substantially different valve area ratio may be achieved..Iaddend.
.Iadd.9. A valve assembly according to claim 8 wherein, when the
ring member is removed, the effective area of the diaphragm means
with respect to the discharge port is substantially changed,
significantly increasing the valve area
ratio..Iaddend. .Iadd.10. A valve assembly according to claim 8
wherein said ring member includes a portion that extends into said
pressure chamber and mates with a section of the diaphragm means,
said ring member thereby substantially changing the amount of force
required to disengage the diaphragm from said discharge
port..Iaddend. .Iadd.11. A valve assembly according to claim 8
wherein the plane defined by the inner portion of the ring member
is laterally offset from the plane defined by the rim of the ring
member, said laterally offset inner portion of the ring member
supporting said predetermined portion of said diaphragm means
thereby occluding said portion of the diaphragm from extending
across said discharge port..Iaddend. .Iadd.12. A valve assembly
according to claim 11 wherein said ring member is positioned
between said diaphragm means and said discharge port, and wherein
said diaphragm means includes a section extending away from said
discharge port and configured to arch over said ring
member..Iaddend.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to respiratory therapy devices, and more
particularly, to the design and construction of an exhalation valve
assembly which can be modified for use in various volume ventilator
circuits.
2. Prior Art
Volume ventilator circuits utilize an exhalation valve assembly to
hold and maintain pressure within the circuit and selectively
allowing gases to be exhaled by the patient and to escape
therefrom. Such valve assemblies are comprised of a valve body and
have a gas inlet conduit, which forms a gas discharge port within
the valve body, and a gas outlet conduit. A flexible diaphragm
selectively closes off the discharge port during inspiration. When
the patient exhales, the diaphragm is pushed away from the port so
as to allow the exhaled gases to escape from the valve body through
the gas outlet conduit.
The pressure holding capability of a volume ventilator circuit is
dependent upon a number of factors including the ratio of the area
of the diaphragm which extends across the chamber of the valve
(hereinafter referred to as the "effective area") to the area of
the gas discharge port. For ease of reference, the ratio of the
effective area of the diaphragm to the area of the discharge port
is referred to herein as the "valve area ratio."
One of the most widely used volume ventilators in the respiratory
therapy field has a limited capability for holding elevated
Positive End Expiration Pressure ("P.E.E.P.") when using a circuit
with a valve assembly having a valve area ratio usually below 1.5.
The valve assembly used in such a circuit is specifically designed
to achieve this ratio and cannot be modified so as to be used in
another circuit requiring a different ratio.
Another popular volume ventilator works on a somewhat different
principal. This machine is not dependent upon the valve area ratio
for high P.E.E.P. pressures, but is dependent on the valve area
ratio for low patient exhalation effort beyond P.E.E.P. pressures.
To achieve the required valve area ratio, the valve assembly is
specifically designed and cannot be modified to provide a different
valve area ratio for use in a different machine.
Thus, prior art volume ventilators have required the use of
specifically designed valve asemblies in order to achieve the
desired valve area ratio. Notwithstanding the increased costs of
manufacturing one specific valve for one type of machine and yet
another valve for another type of machine, the prior art has been
unable to provide any interchangeability of such valve
assemblies.
In other pressure circuits, the valves are also specifically
designed for each circuit. An example of a prior art valve assembly
for use in a pneumatic control system is shown in U.S. Pat. No.
3,633,605. This valve assembly employs a flexible diaphragm which
selectively closes off one of two inlet ports. When the pressure
from gas entering one inlet port is greater than that in the other
inlet port, the diaphragm is pushed away from that port with the
higher pressure, opening it to gas flow. The other port is
occluded, thereby preventing gas flow. This valve assembly is
designed such that there is no easy way to change the valve area
ratio without constructing a whole new housing and diaphragm each
having different dimensions. Because of this fact, such valve
assembly cannot easily be used in a different system requiring a
different valve area ratio.
Yet another valve assembly is disclosed in U.S. Pat. No. 3,419,031.
The valve shown in that patent also suffers from the above
identified limitations. More specifically, such valve assembly
includes a specifically designed resilient valve element which has
dimensions related to the dimensions of the inlet and outlet
conduits. As discussed hereinabove, it is not readily apparent how
one could alter such assembly so as to use the valve in a different
system.
Thus, the prior art valve assemblies suffer from the shortcoming of
using a specifically configured valve assembly. This leads to a
proliferation of valve assemblies all fundamentally designed to
perform the same function. The present invention overcomes these
problems by providing a valve assembly which can be easily modified
so as to achieve different valve area ratios. In this manner, one
valve body can be made for use in different environments. The
expense of constructing entirely different valve assemblies for use
in different pressure circuits is thereby obviated.
SUMMARY OF THE INVENTION
It is one object of the present invention to provide an exhalation
valve assembly with a simple, inexpensive means for changing the
area ratio of the valve without entirely reconstructing such
valve.
Another object of this invention is to provide an exhalation valve
assembly which can be used in different volume ventilator
circuits.
In general, the exhalation valve assembly of the present invention
is designed for use in gas flow circuitry such as a volume
ventilator circuit. The valve assembly includes a valve body having
a chamber in flow communication with a gas inlet conduit and a gas
outlet conduit. The gas inlet conduit is configured to be coupled
to a patient connection such that exhaled gases from the patient
are directed through a gas discharge port into a chamber formed in
the valve body. The gas outlet conduit directs the exhaled gas out
of the chamber.
A diaphragm extends across the chamber formed in the valve body,
and is configured to selectively close off the discharge port. The
diaphragm is held in position by a removable cap which permits the
easy replacement of the diaphragm with diaphragms of different
configurations.
Circumferentially disposed around the chamber on the internal wall
of the valve body are a plurality of upwardly extending strut
members. These strut members are used to support a ring member
which supports a portion of the diaphragm from extending across the
chamber. This reduces the effective area of the diaphragm.
Accordingly, when the ring member is used, the ratio of the
effective area of the diaphragm to the area of the discharge port
is decreased.
By the use of the valve assembly of the present invention, the
valve area ratio can easily be modified so as to meet the needs of
the specific circuit in which the assembly is to be used. More
specifically, one need merely remove the cap from the assembly,
remove the diaphragm and ring member, and insert a different
diaphragm or diaphragm/ring combination. The cap is then replaced
and the assembly is now ready to be used.
The operation of the valve assembly in any configuration basically
is the same. During inspiration, the diaphragm closes off the
discharge port thus preventing any gas from traveling through the
valve assembly. This action is achieved by the application of
positive pressure over the diaphragm as more fully discussed
herein. Upon exhalation, the exhaled gas travels through the inlet
conduit. The pressure exerted by the gas forces the diaphragm to
disengage from the discharge port thereby allowing the exhaled gas
to enter the body of the valve where it is directed out of the
valve body through the outlet conduit. If a ring member is being
used, the pressure needed to disengage the diaphragm from the
discharge port is less than if a diaphragm is used without a ring
member. This is because the ring member supports a portion of the
diaphragm thus reducing its effective area. The valve area ratio
(effective area of the diaphragm--area of discharge port) is
greater without the ring member than with the ring member. Thus, by
using a specific diaphragm and ring combination or omitting the
ring member, the valve assembly can be modified so as to meet the
specific valve area ratio needs of a given volume ventilator
circuit.
The novel features which are believed to be characteristic of the
invention, both as to its organization and method of operation,
together with further objectives and advantages thereof, will be
better understood from the following description considered in
connection with the accompanying drawings in which a presently
preferred embodiment of the invention is illustrated by way of
example. It is to be expressly understood, however, that the
drawings are for the purpose of illustration and description only,
and are not intended as a definition of the limits of the
invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded perspective view of the exhalation valve
assembly of the present invention;
FIG. 2 is a perspective view of one of the diaphragms used with the
valve assembly of the present invention;
FIG. 3 is a cross-sectional view taken along lines 2--2 of FIG. 1
and showing the internal aspects of the valve assembly using a
first diaphragm; and
FIG. 4 is a cross-sectional view taken along lines 2--2 of FIG. 1
and showing the internal aspects of the valve assembly using a
second diaphragm.
DETAILED DESCRIPTION OF THE INVENTION
1. The Device
Referring first to FIG. 1, the valve assembly 10 of the present
invention is shown. The valve assembly 10 is comprised of a valve
body 12 forming a generally circular housing 14 defining a chamber
16. An inlet conduit 18 and an outlet conduit 20 are in flow
communication with chamber 16. Disposed on the inside wall of the
valve body 12 are a plurality of upwardly extending support members
or struts 28. As is hereinafter discussed, such support members 28
are used to position a ring member inside the housing 14. Also
disposed on the valve body 12, adjacent the bottom thereof, is an
outwardly extending and generally rectangular mounting support
member 22. Such mounting support member 22 enables the valve
assembly 10 to be attached to a support structure (not shown) and
thereby held in a predetermined position.
One end of the inlet conduit 18 includes a section 26 which extends
into the chamber 16 and forms a circular gas discharge port 24. In
the preferred embodiment, port 24 is circumferentially disposed in
chamber 16. The other end of the inlet conduit 18 as well as the
outlet conduit 20 each have specifically configured coupling ends
30 as are well known in the art. Such ends 30 enable the conduits
to be readily joined to flexible tubing (not shown) or to other
elements in a volume ventilator circuit.
The valve assembly 10 also includes a flexible, circular diaphragm
member 32 which is disposed across the chamber 16. A cap or cover
34 snap locks onto the body 12 as hereinafter described and holds
the diaphragm 32 across the chamber 16. Centrally located on the
cover 34 is a gas inlet port 36 which can be used to direct a gas
into the assembly 10. Note, however, that in the preferred
embodiment, gas from part 36 does not flow into chamber 36, but
only into the area above diaphragm 32. In this manner, the pressure
above the diaphragm 32 can be regulated.
In the first embodiment of the present invention, a circular,
plastic ring member 38 is disposed in the valve body 12 and rests
on the support members 28. This is illustrated in FIGS. 1 and 3. In
the preferred embodiment, ring member 38 is disposed in the body 12
adjacent the periphery of chamber 16 and circumferentially
surrounds the gas discharge port 24. It is to be understood,
however, that other means for supporting ring member 38 in the
valve body 12 are within the scope of this invention. Once the ring
member 38 is in position, the diaphragm 32 is then placed over it.
The diaphragm 32 includes an upwardly extending section 54
configured to arch over the ring member 38, and a generally
circular section 56 which is used to selectively close off the gas
discharge port 24. The diaphragm 32 rests on a grooved area 46
formed by an inner wall 42 and an outer wall 44 on the valve body
12. When the cover 34 is disposed over the diaphragm 32, as is more
clearly shown in FIG. 3, it snap locks over lip 40. More
specifically, a rim 52 on cover 34 snap locks over the lip 40 and
is held in position by outwardly extending tab members 48 formed on
the periphery of the lip 40. A circular ledge 50 formed on an
inside surface of the cover 34 presses the diaphragm 32 into the
groove 46. This holds the diaphragm 32 in position. It is to be
understood, however, that other means for holding the diaphragm 32
in position are within the scope of the invention.
Again referring to FIG. 3, one can see that ring member 38 supports
a portion of the diaphragm 32 thereby occluding such portion of the
diaphragm 32 from extending across the chamber 16. Thus, the
effective area of the diaphragm 32 over the chamber 16 is decreased
thereby decreasing the valve area ratio. In turn, less pressure is
required to raise the diaphragm 32 off of the gas discharge port
24.
A second embodiment of the present invention will now be discussed
with reference to FIGS. 2 and 4. In the second embodiment, the ring
member 38 has been removed and a circular diaphragm 32A of slightly
different configuration than diaphragm 32 is inserted into the
valve body 12. In the second embodiment, with the ring member 38
removed, the diaphragm 32A is configured so as to have a generally
downwardly extending section 58 and a circular section 60 which is
disposed above and adjacent to the discharge port 24. Section 60
acts to close off discharge port 24 in the same manner as section
56 of the first diaphragm 32. All the other elements of the valve
body 12 in the second embodiment remain the same.
2. Operation of the Valve Assembly
The operation of the valve assembly 10 of the present invention
will now be discussed. In operating the valve assembly 10 in one
manner, a patient connection hose (not shown) is joined to the gas
inlet conduit 18 and secured thereto by means of the coupling end
30. Likewise, an outlet hose (not shown) is joined to the gas
outlet conduit 20 and secured thereto by coupling end 30. During
inspiration, it is necessary to maintain a positive pressure above
diaphragm 32. Therefore, a gas supply tube is joined to the gas
inlet port 36 on the cover 34 such that a gas is directed into the
assembly 10 above the diaphragm 32 or 32A. This enables a positive
pressure to be created above the diaphragm. During exhalation, it
is sometimes desirable to maintain a positive pressure above the
diaphragm, thus forcing the patient to exert an elevated pressure
in order to exhale past the diaphragm. The elevated pressure
exerted is determined by the air pressure applied above the
diaphragm and the valve area ratio. It is to be understood,
however, that in other applications, it may be desirable not to
maintain such positive pressure. In that case, no pressure would be
maintained above diaphragm during exhalation.
Referring now to FIG. 3 one can see arrows 70 which generally
indicate the flow of gas for example, exhaled gas from a patient,
as it would be directed through the assembly 10 in the first
embodiment of the present invention. More specifically, when the
patient exhales with sufficient pressure, the pressure above the
diaphragm 38 (positive pressure supplied by a gas source or
atmospheric) is overcome. This causes the diaphragm 32 to disengage
port 24. The exhaled gas then flows through the inlet conduit 18,
through gas discharge port 24 and into the chamber 16. The exhaled
gas would flow out of the chamber 16 through the outlet conduit 20.
During inspiration a positive pressure is created in the assembly
10 above diaphragm 32 causing section 56 of the diaphragm 32 to
engage port 24. This prevents gas from escaping from the patient
circuit through the valve assembly 10. Air or other gas to the
patient comes from the ventilator, connected to patient circuit
upstream from valve assembly 10.
As discussed hereinabove, prior art ventilator circuits were
designed such that specific amounts of pressure were required in
order to cause the diaphragm 32 to disengage the discharge port 24
thereby permitting escape of the exhaled gas. The present invention
enables this to take place, and further enables such pressure to be
regulated by the use of a specifically designed ring member and
diaphragm. Ring member 38 extends towards the center of the chamber
16 and in one embodiment supports a portion of the diaphragm 32.
Because ring 38 acts as a support for a section of the diaphragm
32, the amount of force necessary to disengage the diaphragm 32
from the discharge port 24 is decreased. If one desired to increase
the force necessary to disengage the diaphragm 32 from the port 24,
the ring member 38 could be removed and/or a different diaphragm or
ring used. For example, in the second embodiment the pressure
necessary to disengage the diaphragm from the port 24 is increased
by interchanging diaphragm 32 with diaphragm 32A and by removing
the ring member 38 from the assembly 10. Diaphragm 32A is not
supported by any ring member and therefore a larger effective area
is presented. This larger effective area necessitates the use of
more pressure in order to disengage the diaphragm 32A from the
discharge port 24. It has been found that by using diaphragm 32 and
ring member 38, the valve area ratio is approximately 1:1 although
modification in the ring 38 or diaphragm 32 can lead to a valve
area ratio between 1:1 and 2:1. Using diaphragm 32A without any
ring member yields a valve area ratio of approximately 2:1. Other
valve area ratios greater than 2:1 are also within the scope of the
present invention.
Thus, the present invention provides a solution whereby one valve
body may be produced and used in a variety of pressure circuits. If
one desires to change the effective area ratio of the valve
assembly 10, the cover 34 can easily be removed from the body 10 by
merely snapping the cover 34 off the lip 40 and by removing the
diaphragm 32 as well as the ring member 38. Another diaphragm, for
example, diaphragm 32A, can then be inserted and the cover 34 again
snapped on to the valve body 12. The assembly 10 is now ready for
use in a different circuit requiring a different valve area
ratio.
A wide variety of materials, shapes and other configurations can be
used in this invention. It should therefore be understood that
changes can be made without departing from the overall scope or
spirit. For example, in the preferred embodiment all of the parts
of the present invention are made out of plastic material such as
nylon, PVC, acrylic resins and the like. Of course, other materials
such as reinforced plastics or even metals are within the scope of
the present invention. Further, the shape of the diaphragm and the
ring member can be modified so as to achieve various valve area
ratios. This invention, therfore, is not to be limited to the
specific embodiments discussed and illustrated herein.
* * * * *