U.S. patent number 3,900,276 [Application Number 05/360,819] was granted by the patent office on 1975-08-19 for diaphragm pump method and apparatus.
This patent grant is currently assigned to McCulloch Corporation. Invention is credited to John Lewis Dilworth.
United States Patent |
3,900,276 |
Dilworth |
August 19, 1975 |
Diaphragm pump method and apparatus
Abstract
An improved method and apparatus in a diaphragm pump of the type
including a frame and a motor connected to the frame. A connecting
rod is eccentrically mounted at one end upon a drive shaft of the
motor and is directly connected at the other end to a flexible pump
diaphragm. A fluid housing is connected to the frame and includes a
fluid entry port and a fluid exit port. The flexible pump diaphragm
is intercalated between the frame and the fluid housing. The
improved apparatus includes a tubular wall coaxially positioned
within the interior of the housing and defining thereby an inlet
chamber within the interior of the tubular wall and an outlet
chamber exterior of the tubular wall and circumferentially
extending about the inlet chamber. A conduit is provided to place
the fluid entry port into fluid communication with the inlet
chamber. A valve plate is mounted between the diaphragm and one end
of the coaxial tubular wall means and defines a pumping chamber
coaxially extending above the inlet and outlet chambers. The valve
plate is provided with a plurality of inlet ports above the inlet
chamber and a plurality of outlet ports above the outlet chamber. A
first valve operably covers the inlet port for permitting fluid to
flow from the inlet chamber into the pumping chamber but preventing
fluid from flowing from the pumping chamber into the inlet chamber.
A second valve operably covers the outlet ports for permitting
fluid to flow from the pumping chamber into the outlet chamber but
preventing fluid from flowing from the outlet chamber into the
pumping chamber. The improved method utilizing the foregoing
apparatus includes the steps of drawing fluid into the coaxial
inlet chamber and pumping the fluid into the circumferential outlet
chamber coaxially disposed about the inlet chamber.
Inventors: |
Dilworth; John Lewis (Santa
Monica, CA) |
Assignee: |
McCulloch Corporation (Los
Angeles, CA)
|
Family
ID: |
23419519 |
Appl.
No.: |
05/360,819 |
Filed: |
May 16, 1973 |
Current U.S.
Class: |
417/542;
417/566 |
Current CPC
Class: |
F04B
43/02 (20130101); F04B 53/1037 (20130101); F04B
11/0033 (20130101); F04B 53/1065 (20130101) |
Current International
Class: |
F04B
11/00 (20060101); F04B 53/10 (20060101); F04B
43/02 (20060101); F04b 011/00 () |
Field of
Search: |
;417/566,542,471,38 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Husar; C. J.
Assistant Examiner: Sessions; O. T.
Attorney, Agent or Firm: Burns, Doane, Swecker &
Mathis
Claims
What is claimed is:
1. In a diaphragm pump including,
a frame means;
a motor connected to said frame means;
a connecting rod eccentrically mounted at one end thereof to a
drive shaft of said motor;
fluid housing means mounted upon said frame means, including
a fluid entry port, and
a fluid exit port; and
flexible pump diaphragm means affixed to said connecting rod at the
other end thereof and intercalated between said frame means and
said fluid housing means;
the improvement comprising:
a first cylindrical tubular wall means coaxially positioned within
said housing means for defining,
an inlet chamber within said tubular wall means, and an outlet
chamber exterior of said tubular wall and interior of said fluid
housing means, said outlet chamber circumferentially extending
about said tubular wall means;
a cylindrical sleeve of volumetrically compressible material
positioned within said inlet chamber about and disposed in full
contact with said first tubular wall means for attenuating fluid
pulsations within said inlet chamber;
a second cylindrical wall concentrically extending radially
outwardly of said tubular wall means to define a concentrically
annular fluid outlet chamber;
a cylindrical sleeve of volumetrically compressible material
positioned within said outlet chamber contiguously extending about
said second cylindrical wall for attenuating fluid pulsations
within said outlet chamber;
conduit means extending between and placing in fluid communication
said inlet port and said inlet chamber;
valve plate means mounted between said diaphragm and one end of
said coaxial tubular wall means and defining a pumping chamber
coaxially extending above said inlet chamber and said outlet
chamber, said valve plate having
a plurality of inlet ports communicating between said inlet chamber
and said pumping chamber, and a plurality of outlet ports
communicating between said pumping chamber and said outlet
chamber;
first valve means operably covering said inlet ports for permitting
fluid to flow from said inlet chamber into said pumping chamber but
preventing fluid from flowing from said pumping chamber into said
inlet chamber;
second valve means operably covering said outlet ports for
permitting fluid to flow from said pumping chamber into said outlet
chamber but preventing fluid from flowing from said outlet chamber
into said pumping chamber, whereby upon actuation of said motor
said eccentric mounted connecting rod will serve to reciprocate
said diaphragm coaxially with said inlet chamber to draw fluid
through said conduit means into said inlet chamber, past said first
valve means into said pumping chamber, and force fluid from said
pumping chamber past said second valve means into said
circumferential outlet chamber and out said exit port.
2. An improvement in a diaphragm pump as defined in claim 1
wherein:
said volumetrically compressible cylindrical sleeve within said
outlet chamber and said volumetrically compressible cylindrical
sleeve within said inlet chamber each are composed of a closed cell
silicone rubber foam.
3. In a diaphragm pump including,
a frame means;
a motor connected to said frame means;
a connecting rod eccentrically mounted at one end thereof to a
drive shaft of said motor;
fluid housing means mounted upon said frame means, including
a fluid entry port, and
a fluid exit port; and
flexible pump diaphragm means affixed to said connecting rod at the
other end thereof and intercalated between said frame means and
said fluid housing means;
the improvement comprising:
a first cylindrical tubular wall means coaxially positioned within
said housing means for defining an inlet chamber within said first
cylindrical wall means;
a second cylindrical wall means concentrically extending radially
outwardly of said first wall means to define a concentrically
annular fluid outlet chamber exterior of said first cylindrical
wall and interior of said second cylindrical wall means, said
outlet chamber circumferentially extending about said first
cylindrical wall means;
a cylindrical sleeve of volumetrically compressible material lining
said first cylindrical wall means within said inlet chamber for
attenuating fluid pulsations within said inlet chamber;
a cylindrical sleeve of volumetrically compressible material
positioned within said outlet chamber contiguous about said second
cylindrical wall for attenuatig fluid pulsations within said outlet
chamber;
said volumetrically compressible cylindrical sleeve within said
outlet chamber and said volumetrically compressible cylindrical
sleeve within said inlet chamber each are composed of a closed cell
silicone rubber foam;
a cylindrical filter screen coaxially positioned within said inlet
chamber in a posture contiguous to and interiorly of said
cylindrical sleeve of volumetrically compressible material within
said inlet chamber for supporting said sleeve within said inlet
chamber and for filtering foreign matter from fluid entering said
inlet chamber;
conduit means extending between and placing in fluid communication
said inlet port and said inlet chamber;
valve plate means mounted between said diaphragm and one end of
said coaxial tubular wall means and defining a pumping chamber
coaxially extending above said inlet chamber and said outlet
chamber, said valve plate having
a plurality of inlet ports communicating between said inlet chamber
and said pumping chamber, and a plurality of outlet ports
communicating between said pumping chamber and said outlet
chamber;
first valve means operably covering said inlet ports for permitting
fluid to flow from said inlet chamber into said pumping chamber but
preventing fluid from flowing from said pumping chamber into said
inlet chamber;
second valve means operably covering said outlet ports for
permitting fluid to flow from said pumping chamber into said outlet
chamber but preventing fluid from flowing from said outlet chamber
into said pumping chamber, whereby upon actuation of said motor
said eccentric mounted connecting rod will serve to reciprocate
said diaphragm coaxially with said inlet chamber to draw fluid
through said conduit means into said inlet chamber, past said first
valve means into said pumping chamber, and force fluid from said
pumping chamber past said second valve means into said
circumferential outlet chamber and out said exit port;
said cylindrical sleeve of volumetrically compressible material
positioned within said inlet chamber is cut at one end by an
inclined plane; and
a landing column is fashioned within the interior of said inlet
chamber in a posture diametrically opposed to said conduit means
extending into said inlet chamber, whereby the greatest height of
said cylindrical sleeve is operable to rest upon said landing
column and be supported thereby while the shortest height of said
cylindrical sleeve longitudinally extends above the opening of said
conduit means and wherein said cylindrical sleeve of volumetrically
compressible material is held in a circumferential posture adjacent
the inlet ports within said valve plate.
4. In a diaphragm pump including
a frame means;
a motor connected to said frame means;
a connecting rod eccentrically mounted at one end thereof to a
drive shaft of said motor;
fluid housing means mounted upon said frame means, including
a fluid entry port, and
a fluid exit port; and
flexible pump diaphragm means affixed to said connecting rod at the
other end thereof and intercalated between said frame means and
said fluid housing means;
the improvement comprising:
tubular wall means coaxially positioned within said housing means
for defining,
an inlet chamber within said tubular wall means, and an outlet
chamber exterior of said tubular wall and interior of said fluid
housing means, said outlet chamber circumferentially extending
about said tubular wall means;
a sleeve of volumetrically compressible material lining the
interior wall of said tubular wall means for attenuating fluid
pulsations within said inlet chamber;
conduit means extending between said and placing in fluid
communication said inlet port and said inlet chamber;
valve plate means mounted between said diaphragm and one end of
said coaxial tubular wall means and defining a pumping chamber
coaxially extending above said inlet chamber and said outlet
chamber, said valve plate having
a plurality of inlet ports communicating between said inlet chamber
and said pumping chamber, and a plurality of outlet ports
communicating between said pumping chamber and said outlet
chamber;
first valve means operably covering said inlet ports for permitting
fluid to flow from said inlet chamber into said pumping chamber but
preventing fluid from flowing from said pumping chamber into said
inlet chamber;
second valve means operably covering said outlet ports for
permitting fluid to flow from said pumping chamber into said outlet
chamber but preventing fluid from flowing from said outlet chamber
into said pumping chamber, whereby upon actuation of said motor
said eccentric mounted connecting rod will serve to reciprocate
said diaphragm coaxially with said inlet chamber to draw fluid
through said conduit means into said inlet chamber, past said first
valve means into said pumping chamber, and force fluid from said
pumping chamber past said second valve means into said
circumferential outlet chamber and out said exit port.
5. An improvement in a diaphragm pump as defined in claim 4 and
further comprising:
a volumetrically compressible material positioned within said
outlet chamber for attenuating fluid pulsations within said outlet
chamber.
6. An improvement in a diaphragm pump as defined in claim 5
wherein:
said volumetrically compressible cylindrical sleeve within said
outlet chamber and said volumetrically compressible cylindrical
sleeve within said inlet chamber each are composed of a closed cell
silicone rubber foam.
7. In a diaphragm pump including,
a frame means;
a motor connnected to said frame means;
a connecting rod eccentrically mounted at one end thereof to a
drive shaft of said motor;
fluid housing means mounted upon said frame means, including
a fluid entry port, and
a fluid exit port; and
flexible pump diaphragm means affixed to said connecting rod at the
other end thereof and intercalated between said frame means and
said fluid housing means;
the improvement comprising:
a first cylindrical tubular wall means coaxially positioned within
said housing means for defining,
an inlet chamber within said tubular wall means, and an outlet
chamber exterior of said tubular wall and interior of said fluid
housing means, said outlet chamber circumferentially extending
about said tubular wall means;
a second cylindrical wall concentrically extending radially
outwardly of said tubular wall means to define a concentrically
annular fluid outlet chamber;
a cylindrical sleeve of volumetrically compressible material
positioned within said outlet chamber contiguously extending about
said second cylindrical wall for attenuating fluid pulsations
within said outlet chamber;
conduit means extending between and placing in fluid communication
said inlet port and said inlet chamber;
valve plate means mounted between said diaphragm and one end of
said coaxial tubular wall means and defining a pumping chamber
coaxially extending above said inlet chamber and said outlet
chamber, said valve plate having
a plurality of inlet ports communicating between said inlet chamber
and said pumping chamber, and a plurality of outlet ports
communicating between said pumping chamber and said outlet
chamber;
first valve means operably covering said inlet ports for permitting
fluid to flow from said inlet chamber into said pumping chamber but
preventing fluid from flowing from said pumping chamber into said
inlet chamber;
second valve means operably covering said outlet ports for
permitting fluid to flow from said pumping chamber into said outlet
chamber but preventing fluid from flowing from said outlet chamber
into said pumping chamber, whereby upon actuation of said motor
said eccentric mounted connecting rod will serve to reciprocate
said diaphragm coaxially with said inlet chamber to draw fluid
through said conduit means into said inlet chamber, past said first
valve means into said pumping chamber, and force fluid from said
pumping chamber past said second valve means into said
circumferential outlet chamber and out said exit port;
a cylindrical sleeve of volumetrically compressible material
positioned within said inlet chamber for attenuating fluid
pulsations within said inlet chamber;
said volumetrically compressible cylindrical sleeve within said
outlet chamber and said volumetrically compressible cylindrical
sleeve within said inlet chamber each are composed of a closed cell
silicone rubber foam; and
a cylindrical filter screen coaxially positioned within said inlet
chamber in a posture contiguous to and interiorly of said
cylindrical sleeve of volumetrically compressible material within
said inlet chamber for supporting said sleeve within said inlet
chamber and for filtering foreign matter from fluid entering said
inlet chamber.
Description
BACKGROUND OF THE INVENTION
This invention relates to improvements in a diaphragm pump method
and apparatus. More particularly, the invention pertains to
improved methods and apparatus within the pumping chamber of a
diaphragm pump.
A continuing demand exists in the pump industry for relatively
small, inexpensive fluid pumps of the type which may, for example,
be advantageously utilized in connection with recreational
vehicles. In this connection, bilge pumps for boats, water pumps
for mobile trailers, etc. are generally representative of current
industry requirements.
Previously known pump designs operable to be used for recreational
vehicles, etc. frequently entail the use of a small electric motor
which is mounted upon the frame and serves to drive an
eccentrically mounted connecting rod. The connecting rod is
connected to a flexible diaphragm which is intercalated between the
frame and a cylindrical fluid housing. The fluid housing is divided
into halves by a central diametrical wall. An inlet is fashioned
into the housing on one side of the wall and an outlet is fashioned
into the housing on the other side of the wall. Therefore, one of
the halves comprises an inlet chamber and the other half comprises
an outlet chamber.
A valve plate is mounted on top of the fluid housing and beneath
the flexible diaphragm to define a pumping chamber above the inlet
and outlet chambers. The valve plate carries an inlet check valve
assembly above the inlet chamber and an outlet check valve assembly
above the outlet chamber.
In operation the foregoing briefly described diaphragm pump
structure serves to draw fluid into the inlet chamber and pump the
fluid over the dimetrical wall into the outlet chamber.
In order to reduce fluid pulsations within the pumping system,
hollow dome bladders are mounted at the bottom of the inlet and
outlet chambers. These bladders serve to flex against closed air
pockets to absorb fluid pulsations.
For a more detailed description of at least one previously known
diaphragm pump of the type briefly described above, reference may
be had to a Russell U.S. Pat. No. 3,606,597 issued Sept. 20,
1971.
Notwithstanding the advantageous aspects at least theoretically
attributable to small fluid pumps of the foregoing design, room for
significant improvement remains.
In this connection, it would be highly desirable to provide an
improved diaphragm pump of increased efficiency or performance.
Further, it would be desirable to provide a simplified pump design
which is readily manufacturable, easily servicable and
characterized by long life of the individual components. Still
further, it would be highly desirable to provide an improved
diaphragm pump where water hammer and pressure pulsations within
the pumping chamber are effectively attenuated.
OBJECTS AND BRIEF SUMMARY OF THE INVENTION
Objects
It is therefore a general object of the invention to provide a
novel diaphgram pump method and apparatus which will provide
desired results of the type previously described.
It is a specific object of the invention to provide a novel
diaphragm pump method and apparatus wherein the performance or
efficiency of the pumping system is facilitated.
It is a related object of the invention to provide a novel
diaphragm pump method and apparatus wherein the volume of fluid
flow is increased without increasing the exterior size of the fluid
housing.
It is a further object of the invention to provide a novel
diaphragm pump method and apparatus wherein higher fluid pressures
may be accommodated.
It is still a further object of the invention to provide a novel
diaphragm pump method and apparatus wherein the concentricity of
pumping inlet and outlet chambers is maximized with resultant
better distribution of pumping forces upon a flexible
diaphragm.
It is yet a further object of the invention to provide a novel
diaphragm pump method and apparatus wherein water hammer pulsations
within the inlet chamber are effectively attenuated.
It is another object of the invention to provide a novel diaphragm
pump method and apparatus wherein pumping fluid pulsations within
an outlet chamber are effectively attenuated.
It is still another object of the invention to provide a novel
diaphragm pump method and apparatus which is compact and relatively
simple in design, easily manufacturable and servicable.
It is yet another object of the invention to provide a novel
diaphragm pump method and apparatus wherein the individual fluid
chamber components including vibration attenuation means exhibit
rugged long-life characteristics which minimize service
requirements to the pump.
Brief Summary
A diaphragm pump method and apparatus intended to accomplish at
least some of the foregoing objects includes a diaphragm pump
having, a frame and a motor connected to the frame. A connecting
rod is eccentrically mounted at one end upon a drive shaft of the
motor and is directly connected at the other end of a flexible pump
diaphragm. A fluid housing is connected to the frame and includes a
fluid entry port and a fluid exit port. The flexible pump diaphragm
is intercalated between the frame and the fluid housing.
The improved apparatus includes a tubular wall coaxially positioned
within the interior of the housing and defining thereby an inlet
chamber within the interior of the tubular wall and an outlet
chamber exterior of the tubular wall and circumferentially
extending about the inlet chamber. A conduit is provided to place
the fluid entry port into fluid communication with the inlet
chamber. A valve plate is mounted between the diaphragm and one end
of the coaxial tubular wall means and defines a pumping chamber
coaxially extending above the inlet and outlet chambers. The valve
plate is provided with a plurality of inlet ports above the inlet
chamber and a plurality of outlet ports above the outlet chamber. A
first valve operably covers the inlet port for permitting fluid to
flow from the inlet chamber into the pumping chamber but preventing
fluid from flowing from the pumping chamber into the inlet chamber.
A second valve operably covers the outlet ports for permitting
fluid to flow from the pumping chamber into the outlet chamber but
preventing fluid from flowing from the outlet chamber into the
pumping chamber. The improved method utilizing the foregoing
apparatus includes the steps of drawing fluid into the coaxial
inlet chamber and pumping the fluid into the circumferential outlet
chamber coaxially disposed about the inlet chamber.
THE DRAWINGS
Further objects and advantages of the present invention will become
apparent from the following detailed description taken in
conjunction with the accompanying drawings wherein:
FIG. 1 is an axonometric view of a small diaphragm fluid pump;
FIG. 2 is a plan view of a diaphragm fluid pump including a
generally square fluid housing having entrance and exit fluid
ports;
FIG. 3, note sheet 2, is a partial broken-away end view of the
diaphragm pump disclosed in FIGS. 1 and 2 and particularly
illustrates an inlet chamber coaxially mounted within a fluid
housing and a circumferential outlet chamber surrounding the inlet
chamber;
FIG. 4, note sheet 3, discloses a cross sectional view taken along
section line 4--4 in FIG. 2 and illustrates the provision of a
pressure switch tapped into the circumferentially extending outlet
chamber;
FIG. 5 is a cross sectional view taken along section line 5--5 in
FIG. 3 and discloses a partially broken-away plan view of a valve
plate mounted within the fluid housing;
FIG. 6, note sheet 2, discloses a cross sectional view taken along
section line 6--6 in FIG. 3;
FIG. 7, note sheet 1, discloses an axonometric view of a generally
cylindrical elastomeric body composed of a closed cell silicone
rubber foam which is operable to be positioned within the inlet
chamber to attenuate water hammer pulsations within the inlet
chamber; and
FIG. 8 discloses an axonometric view of an expanded cylindrical
elastomeric sleeve composed of closed cell silicone rubber foam and
being operable to attenuate fluid pulsations within the outlet
chamber of the diaphragm pump.
DETAILED DESCRIPTION
Diaphragm Pump Context of the Invention
Before discussing the improvement aspects of the invention, a brief
summary of the diaphragm pump context of the invention will be
discussed.
More particularly, and with reference to FIGS. 1 and 2, there will
be seen a diaphragm type pump 10 including a frame 12 which serves
to support a small electric motor 14. A connecting rod 16 is
eccentrically mounted at one end by a cam 18 which is mounted upon
a drive shaft 20 of the motor. A generally square fluid housing 22
is connected to a top plate 24 of the frame 12 by the provision of
conventional threaded fasteners 26 mounted at each of the corners
of the frame. A fluid inlet port 28 is fashioned within the housing
22 on one side thereof and a fluid exit port 30 is fashioned into
the housing 22 on a generally opposite side thereof. A flexible
diaphragm 32, note FIG. 3, is connected to the other end of the
connecting rod 16 by interior and exterior diaphragm discs 34 and
36 and a threaded fastener 40.
Improved Fluid Chamber
Referring now particularly to FIGS. 3-6, there will be seen various
views of an improved fluid chamber comprising the subject matter of
the instant invention.
As noted in FIG. 6, the generally square fluid chamber 12 is
provided with a central longitudinally extending axis 42. A tubular
cylindrical wall 44 is coaxially positioned with respect to axis 42
within the interior of the housing 22 and serves to define by the
interior surface thereof a fluid inlet chamber 46.
A second cylindrical tubular wall 48 is coaxially positioned within
the interior of the fluid chamber 22 and is concentrically
outwardly positioned with respect to the wall 44. The annular
cylinder between the exterior surface of wall 44 and the interior
surface of wall 48 defines a generally cylindrical outlet chamber
50 circumferentially extending about the inlet chamber 46.
In order to provide fluid communication between the entry or inlet
port 28 and the inlet chamber 46, a conduit 52 is fashioned through
the wall of the housing 22, through the tubular wall 44, and opens
into the inlet chamber 46.
A valve plate 54 is mounted upon the upper surface of cylindrical
wall 44 and a plurality of supporting columns 56 positioned at
regular intervals about the inner periphery of wall 48. The valve
plate 54 is formed with an inner cup 57 including a cylindrical
side wall 58 and a bottom plate 60. The cylindrical side wall 58 is
coaxially disposed with respect to axis 42 and upwardly projects
into abutting contact with the flexible diaphragm 32. The
cylindrical wall 58 serves to pin the diaphragm against the under
portion of plate 24 to define coaxially above the inlet and exit
chambers a pumping chamber 62.
The bottom wall 60 of the cup 56 is fashioned with a plurality of
fluid inlet ports 64 having axes which lie upon an imaginary ring
coaxially disposed with respect to central axis 42. Radially
outwardly from the inlet ports 64 are a plurality of outlet ports
66 which lie upon an imaginary circle concentrically outwardly
disposed with respect to the imaginary circle of the inlet ports
(note FIG. 5).
An aperture 68 is fashioned through the center of the valve plate
54 and is operable to receive a mounting stub 70 of an umbrella
valve 72. The umbrella valve 72 is composed of an elastomeric
material and serves to overlie and normally cover each of the inlet
ports 64 lying within the confines of the cylindrical wall 44 which
defines the inlet chamber 46. It will be appreciated that umbrella
valve 72 is in essence an elastomeric check valve in that fluid is
free to flow from the inlet chamber 46 to the pumping chamber 62
but upon pressurization of the pumping chamber 62 the umbrella
valve 72 will flex into sealing abutment above the ports 64 and
thus prevent fluid from entering the inlet chamber.
The valve plate 54 is fitted with a second valve 74 composed of an
elastomeric disc or washer which is mounted between a lower portion
of the valve plate 54 and the upper free end of the cylindrical
wall 44 as at 76.
The elastomeric ring 74 like the umbrella valve 72 in essence
serves as a check valve in that fluid confined within the pumping
chamber 62 will serve to flex the valve 74 downwardly and thus
permit the flow of fluid through outlet ports 66 peripherally about
the inlet chamber 64. However, in the event pressure within the
outlet chamber 50 is greater than pressure within the pumping
chamber 62, the elastomeric valve will flex closed and prevent
fluid from flowing from the outlet chamber 50 into the pumping
chamber 62.
In order to limit the downward flexure of the elastomeric disc
valve 74 a valve guard or disc 77 is also mounted at the free end
of the cylindrical wall 44 and is normally flexed slightly downward
to permit a normal flexing of elastomeric valve 74. The guard or
backup disc 76 is perferably composed of a metallic material such
as, for example, stainless steel, which will exhibit
characteristics of long life while providing appropriate strength
to prevent the elastomeric valve 74 from overflexing. In this
connection, overflexing of valve 74 may produce excessive wear at
the flexure point 78. Alternatively, the valve may open too wide to
accommodate rapid osscillations of the pumping diaphragm 32.
In order to reduce and attenuate momentum pulsations created within
the inlet chamber 46 by the rapid opening and closing of the
umbrella valve 72, a cylindrical sleeve 80 composed of a
volumetrically compressable material such as closed cell silicone
rubber foam is positioned within the interior of the cylindrical
inlet chamber 46. The sleeve 80 is cut at one end by a plane lying
normal to the axis of the sleeve as at 82 and is positioned to abut
against the bottom face of the valve plate 54. The other end of the
sleeve 82 is cut by an inclined plane (note FIG. 3) such that the
longest height of the sleeve 80 abuts against an inwardly
projecting column 84 which is integrally fashioned with respect to
cylindrical wall 44. Column 84 serves to maintain the
volumetrically compressable sleeve 80 in a posture adjacent to the
inlet ports 64 and thus facilitate attenuation of "water hammer"
vibration produced by the rapid shutting of umbrella valve 72.
The shortest height of the sleeve 80 which is diametrically opposed
to the landing column 84 extends above the inlet of the conduit 52
as at 86 to enable fluid to freely enter into the inlet chamber
46.
A cylindrical sleeve 88 composed of a fine mesh screen is mounted
coaxially within the inlet chamber 46 and contiguously lies against
the inner surface of the elastomeric sleeve 80. The screen 88
provides a dual function of removing foreign particles from the
flow of fluid into the inlet chamber 46 and assisting the landing
tab 84 in maintaining the elastomeric sleeve 80 in a posture
adjacent to the inlet ports 64.
To minimize and attenuate fluid pumping pulsations within the
outlet chamber 50 a second cylindrical sleeve 89 is positioned
within the clinder 48. The sleeve 89 lies in a posture contiguous
with the inner wall of the cylinder 48 and is preferably composed
of a volumetrically compressable elastomer such as closed cell
silicone rubber foam. The sleeve 89 is fashioned with a first
aperture 90 operable to be positioned within the outlet chamber 50
in a posture adjacent to the exit port 30. Therefore, fluid within
the outlet chamber may freely flow through the sleeve 89 and into
the exit port.
The sleeve 89 (not FIG. 8) is evered in a location diameetrically
opposed to the axis of the first port 90 and formed with channels
92 and 94. Thus, when the sleeve 89 is curved and placed within the
wall 48 during assembly of the fluid housing, the cutouts 92 and 94
form a generally U-shaped recess which is suitable to extend upon
either side of the inlet conduit 52 (note FIG. 6).
In order to control actuation of the motor 44 in accordance with a
preferred pressure ratio within the outlet chamber 50 a commercial
pressure switch 100 is tapped through the fluid housing and opens
through a second aperture 102 formed within the volumetrically
compressable sleeve 89. The pressure switch per se does not form a
part of the invention and may be selected from commercially
available devices such as, for example, the 25 PS series KLIXON
Precision Pressure Switch manufactured by Texas Instruments, Inc.
at Attleboro, Mass.
The pressure switch 100 is operably connected (not shown) to the
motor 14 and serves to turn the motor on and off in response to a
preselected range of pressures such as, for example, 15 to 27
psig.
Operation
In operation, once fluid within the outlet chamber 50 falls below
the 15 psig the switch 100 will actuate the motor 14 thus driving
the connecting rod 16 in an up-and-down reciprocating mode. The
diaphragm 32 will accordingly reciprocate to draw fluid through
conduit 52 into the inlet chamber 46. The umbrella check valve 72
opens during the upstroke of the diaphragm 32 within the pumping
chamber 62. On each downstroke of the diaphragm 32 the elastomeric
umbrella valve 72 will be snapped closed and the disc valves 74
will simultaneously open to permit the fluid to enter outlet
chamber 50.
The foregoing process is rapidly repeated so as to provide a
substantially continuous pumping operation until the pressure
within the outlet chamber 50 reaches a preselected maximum such as,
for example, 27 psig, at which time the pressure switch 100 will
turn the motor 14 off.
SUMMARY OF THE MAJOR ADVANTAGES
In illustrating and describing the foregoing improvements in a
diaphragm pump several novel and advantageous aspects of the
invention have been specifically and inherently disclosed.
A primary advantage provided by the concentric inlet and outlet
chambers is the provision of a greater valving area within
substantially the same exterior fluid chamber configuration whereby
geater flow rates or efficiency may be achieved without
substantially increasing power requirements.
Further significant advantages are realized by the provision of
volumetrically compressable cylindrical sleeves within the inlet
and outlet chambers which serve to attenuate fluid pulsations
within the chambers while minimizing the possibility of incidental
cracks and the like resulting in failure of the vibration
attenuation system. Another advantage is realized by the
cylindrical nature of the outlet or high pressure chamber which
permits a build-up of higher fluid pressures without unduly
stressing the fluid chamber housing members.
Still further, it will be appreciated that the subject improved
fluid chamber in a diaphragm pump is compact and simple in design
which facilitates manufacturing ease and is readily servicable in
the event of failures. In this connection, the vibration
attenuation sleeves, while being extremely long-lifed, may be
readily removed and replaced. Further, the metallic backup ring
prevents overstressing of the second, elastomeric check valve.
Although the invention is disclosed with reference to a preferred
embodiment it will be appreciated by those skilled in the art that
additions, deletions, modifications, substitutions and other
changes not specifically described and illustrated may be made
which will fall within the purview of the appended claims.
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