U.S. patent application number 14/168731 was filed with the patent office on 2014-05-29 for pump actuator and method for pump operation.
The applicant listed for this patent is Stephen B. Maguire. Invention is credited to Stephen B. Maguire.
Application Number | 20140147288 14/168731 |
Document ID | / |
Family ID | 50773463 |
Filed Date | 2014-05-29 |
United States Patent
Application |
20140147288 |
Kind Code |
A1 |
Maguire; Stephen B. |
May 29, 2014 |
PUMP ACTUATOR AND METHOD FOR PUMP OPERATION
Abstract
Method and apparatus for controlling a moveable pumping
diaphragm and a liquid color diaphragm pump, including a housing, a
movable pin slidably residing within the housing, a potentiometer
connected to and residing within the housing for sensing movement
of the pin, riding against the diaphragm of the pump and a spring
for biasing the pin against the diaphragm.
Inventors: |
Maguire; Stephen B.; (West
Chester, PA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Maguire; Stephen B. |
West Chester |
PA |
US |
|
|
Family ID: |
50773463 |
Appl. No.: |
14/168731 |
Filed: |
January 30, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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13913375 |
Jun 7, 2013 |
|
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14168731 |
|
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61660326 |
Jun 15, 2012 |
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Current U.S.
Class: |
417/15 ;
92/172 |
Current CPC
Class: |
F04B 49/12 20130101;
F04B 43/02 20130101; F04B 49/20 20130101; F04B 13/00 20130101; F04B
2203/0204 20130101; F04B 43/073 20130101; F04B 51/00 20130101; F04B
2201/0201 20130101; F04B 49/06 20130101 |
Class at
Publication: |
417/15 ;
92/172 |
International
Class: |
F04B 43/02 20060101
F04B043/02 |
Claims
1) A method for operating a pump having a movable pumping member
and a pumping chamber, comprising: a) positioning a movable
reciprocable member in contact with the pumping member to move
reciprocally in concert with the pumping member; b) sensing
position of the reciprocable member and producing signals
indicative thereof; c) periodically applying force to the pumping
member to move the pumping member and thereby effectuate pumping of
fluid from the chamber; d) using the signals to regulate frequency
of force application to the pumping member to achieve a preselected
rate of output from the pump.
2) The method of claim 1 further comprising: a) recording the
signals at the extremities of reciprocable member travel; b) using
those signals and known length of reciprocable member travel to
determine location of the reciproable member based on signal
received at a given time; c) adjusting the frequency of application
of force to the pumping member according to the location of the
reciprocable member to maintain a desired output from the pump.
3) The method of claim 2 wherein the step of using those signals
and known length of reciprocable member travel to determine
location of the reciproable member based on signal received at a
given time further includes determining the relationship between
duration of force application to the pumping member and pumping
member displacement.
4) The method of claim 1 wherein the pumping member is a
diaphragm.
5) The method of claim 1 wherein the sensing is performed by a
potentiometer.
6) The method of claim 1 wherein the force is pneumatically
applied.
7) The method of claim 1 wherein the pumping chamber is
air-tight.
8) The method of claim 5 wherein the potentiometer is within an
actuator chamber.
9) The method of claim 8 wherein the actuator chamber is
sealed.
10) The method of claim 9 wherein the actuator chamber is within
polymer foam.
11) The method of claim 1 further comprising adjusting the
frequency of application of force to the pumping member according
to the location of the reciprocable member to maintain a desired
output from the pump.
12) The method of claim 2 wherein the force is applied to the
pumping member by bursts of air.
13) The method of claim 1 further comprising the steps of: a)
noting position of the reciprocable member as indicated by a
potentiometer signal; b) applying a burst of air to the pumping
member; c) recording a second potentiometer signal indicative of
reciprocable member position; and d) determining pumping member
movement as a function of applied force duration from the movement
of the reciprocable member in response to the air burst applied to
the pumping member.
14) The method of claim 1 wherein periodically applying force to
the pumping member to move the pumping member and thereby
effectuate pumping of fluid from the chamber is performed by
controlling duration and timing of air bursts applied to the
pumping member.
15) A method for operating a liquid color diaphragm pump,
comprising controlling duration and sequencing of bursts of air
applied to a diaphragm contacting the liquid color being
pumped.
16) A method for operating a liquid color pump having a movable
pumping member and a sealed pumping chamber, comprising: a)
positioning a movable reciprocable member within an actuator
chamber in contact with the pumping member to move reciprocally in
concert with the pumping member; b) sensing position of the
reciprocable member within the actuator chamber and producing
signals indicative thereof; c) periodically pneumatic applying
force to the movable pumping member to move the pumping member and
thereby effectuate pumping of liquid color; d) using the signals to
regulate frequency of pneumatic force application to the pumping
member to achieve a desired rate of output from the pump.
17) An actuator for controlling a movable pumping member in a pump,
comprising: a) a housing; b) a movable pin slidably residing within
the housing, having an extremity portion passing through the
housing for contacting the movable pumping member and moving
unitarily therewith; c) a potentiometer connected to and residing
within the housing for sensing movement of the pin and producing a
signal indicative thereof; and d) a spring for biasing the pin
against the pumping member.
18) Apparatus of claim 17 wherein the housing has a first aperture
for connection to a supply of pulsed air, wherein the housing has a
sealed chamber within the pin, spring and potentiometer reside.
19) Apparatus of claim 17 wherein the potentiometer has a movable
portion positioned between and contacting the spring and the pin,
for movement with the pin.
20) Apparatus of claim 18 wherein a portion of the housing
comprising the chamber is polymer foam.
21) Apparatus of claim 17 wherein the signals are electrical
signals, the potentiometer has terminals providing the electrical
signals indicative of movement of the pin, and the apparatus
further comprises: a) signal carriers electrically connected to the
terminals and passing through housing; and b) electrical connectors
mounted on the housing exterior and being electrically connected to
the signal carriers.
22) Apparatus of claim 20 wherein the signals are electrical
signals, the potentiometer has terminals providing the electrical
signals indicative of movement of the pin, and the apparatus
further comprises: a) signal carriers electrically connected to the
terminals and passing through the polymer foam; and b) electrical
connectors mounted on the chamber exterior and being electrically
connected to the signal carriers.
23) Apparatus of claim 17 wherein the pumping member is a
diaphragm.
24) An actuator for controlling a movable pumping diaphragm in a
liquid color diaphragm pump, comprising: a) a housing; b) a movable
pin slidably residing within the housing, having an extremity
portion passing through the housing for contacting the movable
pumping member and moving unitarily therewith; c) a potentiometer
connected to and residing within the housing for sensing movement
of the pin and producing a signal indicative thereof; and d) a
spring for biasing the pin against the pumping member; wherein the
housing comprises a sealed chamber within which the pin, spring and
potentiometer reside; the potentiometer comprises a movable portion
positioned between and contacting the spring and the pin for
movement with the pin; a portion of the housing comprising the
chamber is polymer foam; the potentiometer has terminals providing
the signals indicative of pin movement; and further comprising e)
signal carriers electrically connected to the terminals and passing
through the polymer foam.
Description
CROSS-REFERENCE TO RELATED PATENT APPLICATION
[0001] This patent application is a continuation-in-part of U.S.
patent application Ser. No. 13/913,375 filed 7 Jun. 2013 in the
name of Stephen B. Maguire and published as U.S. 2013/0334258 A1,
the priority of which is claimed under 35 USC 120. The '375
application claims the benefit of the priority under 35 USC 119 and
35 USC 120 of provisional U.S. patent application Ser. No.
61/660,326 filed 15 Jun. 2012 in the name of Stephen B. Maguire and
entitled "Molded Diaphragm Pump." The instant application similarly
claims the benefit of the priority of the '326 application through
the parent '375 application noted above. The disclosures of both of
these preceding applications are hereby incorporated by reference
in their entireties.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention pertains to pumps and more specifically to
diaphragm and piston pumps used to pump liquid color. The patent
application even more specifically pertains to a device used to
actuate the pumping action of a liquid color diaphragm pump. The
liquid color diaphragm pump is preferably, but not necessarily, a
liquid color pump installed on the lid of a liquid color container.
Most preferably the liquid color pump is an integral part of the
lid of a drum of liquid color container.
[0004] 2. Description of the Prior Art
[0005] Diaphragm pumps and piston pumps are known. In both
diaphragm pumps and piston pumps, the pump provides a reciprocating
action whereby the pump alternately displaces liquid and then pulls
in additional liquid to be pumped from a pumping chamber. All such
pumps involved two check valves. An inlet check valve allows liquid
to enter the pumping chamber, but prevents liquid from exiting back
out of the pumping chamber through the inlet check valve. An outlet
check valve allows the pumped liquid to exit the pumping chamber
and prevents the liquid from returning to the pumping chamber
through the outlet check valve.
[0006] In a diaphragm pump, the moving diaphragm serves to suck
liquid through the inlet into the pumping chamber and then pumps
the liquid by applying pressure to the liquid to force the liquid
out of the pumping chamber via the liquid outlet.
SUMMARY OF THE INVENTION
[0007] In one of its aspects, this invention provides a method for
operating a pump having a moveable pumping member within a pumping
chamber, where the method preferably includes positioning a
moveable reciprocable member in contact with a pumping member to
move reciprocally in concert with the pumping member. In this
aspect, the invention preferably proceeds with sensing position of
the reciprocable member, which is indicative of the position of the
pumping member, and producing a signal indicative thereof. The
method then preferably proceeds in this aspect by periodically
applying force to the pumping member to move the pumping member and
thereby effectuate pumping of liquid from the chamber. The method
preferably further involves using the signals to regulate frequency
of force application to the pumping member to achieve a preselected
rate of output from the pump.
[0008] In one application of the actuator of the invention,
addition of color to a plastic molding or processing operation
requires careful metering, which this invention provides. When such
color is added, the rate of color dispensing must exactly match the
rate requirement of the process machine. Consequently, speed of the
liquid color pumping process must be carefully controlled. In the
instant invention, rate of pumping is controlled and even partial
pumping strokes may be effectuated by the invention preferably
pulsing very small bursts of air into the liquid color pump above
the diaphragm portion of the pump. By regulating the duration of
each air pulse and regulating the time between air pulses, the
invention facilitates metering liquid color at a desired precisely
controlled flow rate.
[0009] The actuator of the invention preferably provides continuous
feedback of the exact position of a liquid color pump diaphragm at
all times as air pushes the diaphragm downward during the pumping
stroke. Such continuous feedback information regarding the exact
position of the diaphragm at all times preferably allows continuous
monitoring and correction of liquid color flow rate by regulation
of the frequency and duration of the air pulses applied to the
diaphragm and also preferably facilitates accurate, partial strokes
of the pumping diaphragm. The invention accomplishes this by
preferably providing a moveable pin that follows the diaphragm of
the liquid color pump as the diaphragm moves down and up. The
invention further accomplishes this by using a linear potentiometer
in a position so that the potentiometer is within the actuator and
senses movement of the pin.
[0010] In a typical application, total movement of the diaphragm
portion of the liquid color pump is preferably about one-quarter of
one inch. The preferred slide potentiometer portion of the actuator
of the invention is preferably capable of about 20 millimeters, or
about three-quarters of an inch, of movement of the sensing slide
of the potentiometer. In the course of practice of the invention,
the upper and lower limits of potentiometer movement are preferably
recorded using a microprocessor and readings in between these upper
and lower limits are preferably used to calibrate the actuator to
determine the precise location of the pin and hence of the
diaphragm as the diaphragm moves up and down and pumps the liquid
color.
[0011] In the most preferred operation of the invention, the
invention utilizes only about one-quarter inch of the diaphragm
movement, which translates into about 300 different position
readings of the moveable potentiometer arm, and hence the position
of the pin riding the diaphragm, and the position of the diaphragm
itself, thereby assuring precise location information at all times
respecting the position of the pumping diaphragm.
[0012] In the preferred manifestation of the invention, the
potentiometer preferably is entirely within a chamber interior of
the actuator, which chamber is pressurized. Electrical signals from
the potentiometer are brought out of the actuator and out of the
pressurized chamber within the actuator preferably via screws that
make contact with the potentiometer connections inside the actuator
that are themselves sealed against air leakage where they enter the
actuator body. The absence of any moving, sliding seals assures
correct operation of the potentiometer and actuator for many years
with there being no wear points to fail.
[0013] A light spring, above the slide arm of the potentiometer and
biasing the actuator pin downwardly, assures that the potentiometer
slide arm or "T-bar" and the actuator pin follow the diaphragm
downwardly as air pushes the diaphragm down.
[0014] The actuator is removable from the pump using a one-quarter
turn locking system with an O-ring base. This allows the actuator
to be installed or removed easily and frequently, while effectively
sealing the actuator against the pump surface whenever the actuator
is installed.
[0015] The method aspect of the invention may preferably further
include recording signals at the extremities of actuator pin
travel, using those signals and the known length of actuator pin
travel to determine location of the actuator pin based on signal
received at a given time and adjusting the frequency of application
of force to the pumping diaphragm according to the location of the
actuator pin and the potentiometer slide arm or T-bar, to maintain
the desired output from the pump.
[0016] The method may further involve using the signals and known
length of the actuator pin travel to determine location of the
actuator pin based on signal received at a given time and may
further include determining the relationship between the duration
of force application to the pumping diaphragm and the pumping
diaphragm displacement.
[0017] In another one of its aspects, this invention provide
apparatus for controlling a moveable pumping member and a pump,
where the apparatus includes a housing, a reciprocally moveable pin
slidably residing within the housing, and having an extremity
portion passing through the housing for contacting the moveable
pumping diaphragm and moving unitarily with the moving pumping
diaphragm. The apparatus aspect of the invention further preferably
includes a potentiometer connected to and residing within the
housing for sensing movement of the pin and producing a signal
indicative thereof, and spring for biasing the pin against the
pumping member. A microprocessor is also included, as is a solenoid
valve, for regulating air bursts applied to the diaphragm to
facilitate pumping.
[0018] In the apparatus aspect of the invention, the housing may
have a first aperture for connection to a supply of pulsed air,
where the housing is otherwise sealed and air tight except
optimally for passage of air along the pin where the pin passes
through the housing.
[0019] In the apparatus aspect of the invention, the potentiometer
desirably has a moveable slide arm or T-bar portion positioned
between and contacting both the light upper spring and the pin. In
the apparatus aspect of the invention, the actuator housing is
preferably at least partially polymer foam. In the apparatus aspect
of the invention, the signals are desirably electrical signals and
the potentiometer desirably has terminals providing the electrical
signals indicative of movement of the pin. In such aspect of the
invention, the apparatus further comprises signal carriers
electrically connected to terminals in passing through the housing,
and electrical connectors mounted on the housing exterior and being
electrically connected to the signal carriers, for connection to
the microprocessor, to in turn activate the solenoid valve to apply
bursts of pumping air to the diaphragm. In the apparatus aspect of
the invention, the pumping member is desirably a diaphragm.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is a front elevation of an actuator embodying aspects
of the invention.
[0021] FIG. 2 is a left side elevation of the actuator illustrated
in FIG. 1.
[0022] FIG. 3 is a right side elevation of the right side actuator
illustrated in FIGS. 1 and 2.
[0023] FIG. 4 is an isometric view of the actuator illustrated in
FIGS. 1 through 3 showing the bottom of the actuator and the left
quarter of the actuator, namely the side portion of the actuator
shown partially in FIG. 1 and partially in FIG. 2.
[0024] FIG. 5 is an isometric view of the actuator illustrated in
FIGS. 1 through 4 showing the right quarter of the actuator, namely
the side portion of the actuator illustrated in FIGS. 1 and
partially in FIG. 3.
[0025] FIG. 6 is an isometric view of the actuator showing the top
of the actuator and the front left quarter side portion illustrated
in FIG. 4.
[0026] FIG. 7 is an isometric view of the actuator showing the top
of the actuator and the front right quarter side portion
illustrated in FIG. 5.
[0027] FIG. 8 is a top view of the actuator illustrated in FIGS. 1
through 7.
[0028] FIG. 9 is a sectional view of the actuator illustrated in
FIGS. 1 through 8, with the section taken at lines and arrows A-A
in FIG. 8.
[0029] FIG. 10 is a sectional view of the actuator illustrated in
FIGS. 1 through 9, with the section taken at lines and arrows B-B
in FIG. 8.
[0030] FIG. 11 is a schematic view, partially in section, showing
the actuator illustrated in FIGS. 1 through 10 together with a
connected microprocessor and a connected solenoid valve.
DESCRIPTION OF THE PREFERRED EMBODIMENTS AND BEST MODE KNOWN FOR
PRACTICE OF THE INVENTION
[0031] The actuator 43 of this invention has specific applicably to
liquid color diaphragm pumps; the actuator may also be used with
piston-type pumps.
[0032] In a pump to which the actuator is best adapted for use,
such as that disclosed in pending U.S. Ser. No. 13/913,375, air is
applied to the top side of the diaphragm, to press the diaphragm
down. This downward movement of the diaphragm defines the "pumping
stoke". In the pump, a spring on the bottom side of the diaphragm
acts against the diaphragm to move the diaphragm up. Upward
movement of the diaphragm in response to the spring pressure
defines the "suction stroke".
[0033] In the preferred pump, normally the diaphragm is operated in
full strokes, moving through the full range of motion for which the
diaphragm is designed in the pump. Moving the diaphragm downward
through the full range of motion is preferably accomplished by
opening a solenoid actuated air valve 70 and applying air pressure
to move the diaphragm preferably all the way to the bottom of its
range of motion, which may be to the bottom of the pumping
cavity.
[0034] When liquid color is used to color plastic parts during
fabrication, careful metering of liquid color consumption is
required as the liquid color is added while the plastic resin is
melted and processed by a process machine. The rate the liquid
color is dispensed by the pump must exactly match the rate at which
the liquid color is consumed by the process machine.
[0035] The rate or speed of the liquid color pumping process must
be precisely controlled. In some applications only require partial
pump strokes are required. The rate at which liquid color is
supplied by the pump is controlled by carefully pulsing only very
small bursts of air into the pump, into the space above the
diaphragm. Regulating the duration of each air pulse and regulating
the time between pulses results in metering the liquid color to the
process machine at exactly the desired flow rate so that the
process machine receives precisely the amount of liquid color the
process requires, at exactly the right rate of supply of liquid
color.
[0036] Critical to the success of this process for supplying liquid
color is having continuous feedback of the exact position of the
diaphragm at all times as compressed air released by solenoid valve
70 pushes the diaphragm downward. Knowing the exact position of the
diaphragm at all times allows accurate continuous monitoring and
correction of the liquid color flow rate by regulation of the
solenoid valve by the potentiometer and microprocessor, and also
allows accurate metering of partial stokes of the diaphragm.
[0037] The actuator of this invention accomplishes this by
providing a pin 42 that lightly rides the surface of the diaphragm,
following the diaphragm as the diaphragm moves down and up. The
actuator 43 of this invention further involves positioning a
potentiometer 36, most desirably a linear potentiometer, so that
potentiometer 36 is actuated by movement of pin 42. In one
preferred embodiment, total diaphragm movement in the invention may
be about 0.25 inch. The potentiometer arm 40 and pin 42 may move
about 0.75 inch or more, but in the preferred embodiment, the
invention typically uses only 0.25 inch of that stroke.
[0038] Initially, a microprocessor 68 records the upper and lower
extreme positions of the linear potentiometer slider arm 40,
corresponding to the upper and lower limits of diaphragm travel.
The microprocessor 68 then uses the readings of the potentiometer
slider arm 40 that are between the corresponding upper and lower
limits of diaphragm travel to determine the exact location of the
diaphragm as the diaphragm moves up and down and pumps liquid
color. The 0.25 inch of stroke of the diaphragm translates into
about 300 different position readings of the pin 42 and
potentiometer slider arm 40, which may be stored and used by the
microprocessor, assuring precise readout of diaphragm location at
any time.
[0039] The invention provides pin 42 for physical connection of
potentiometer 36 with the top side of a diaphragm. This is to sense
the movement of the diaphragm. Using a moving pin passing through
an air pressure seal would risk leaking air around the seal. Any
such air leak, even the slightest air leak, would compromise
metering accuracy.
[0040] The invention has no parts moving through a seal. The
potentiometer and pin are enclosed entirely within an actuator
internal chamber 274 that is pressurized.
[0041] Electrical signals from the potentiometer are brought out of
the pressurized volume of actuator internal chamber 274 through
screws 257 making contact with potentiometer electrical leads 268,
which in turn connect with the potentiometer electrical leads 270
inside the pressurized volume; the screws themselves are sealed
against air leakage where they enter the pressurized chamber.
Absence of any moving or sliding seals assures correct operation
for many years with no wear points to fail.
[0042] A light spring 38, above slide portion 40 of potentiometer
36 and bearing on pin 42, assures that pin 42 follows the diaphragm
down as the air pushes the diaphragm down. Preferably a heavy pump
spring, inside a preferred pump, pushes the diaphragm up at the end
of a pump stoke, and the diaphragm then pushes pin 42 and
potentiometer slide portion 40 up against the bias of light spring
38.
[0043] The actuator 43 is removable from the pump. Preferably a
one-quarter turn locking system with an O-ring base seal allows the
actuator to be installed or removed easily while effectively
sealing against the pump surface.
[0044] In the drawings it can be seen that that actuator 43 is
generally cylindrical in form, with an air inlet 44 at the top
thereof being fed by an air supply line 45, which supplies air
indirectly with the air being controlled by solenoid valve 70
preferably operating off of a house air line 74. A microprocessor
68 receives signals from the slide potentiometer designated
generally 36 which is resident within actuator 43. Also resident
within actuator 43 is light biasing spring 38 which works to bias
actuator pin 42 and intervening T-bar portion 40 of slide
potentiometer 36 downwardly. This downward bias of actuator pin 42
assures that the end of actuator pin 42 is always riding on the
diaphragm of a pump being controlled by actuator 40.
[0045] The diaphragm of the pump does the actual pumping. Spring
38, slide potentiometer 36 and actuator pin 42 monitor the position
of the diaphragm in the pumping chamber as the diaphragm moves in
response to air pressure, most desirably bursts of air pressure,
applied to the top side of the diaphragm as air passes downwardly
around the edges of actuator pin 42, as the air is released by
intermittent operation of solenoid valve 70 when triggered by
microprocessor 68. The air maintains a pressurized condition within
actuator internal chamber 274.
[0046] Actuator 43 has an upper portion 250 and a lower portion 252
which are connected and held together by hold down bolts 256. An
actuator internal gasket 254 resides between actuator upper portion
250 and actuator lower portion 252.
[0047] Actuator upper portion 250, within which actuator chamber
274 is located, is preferably insulative, air tight polymer
foam.
[0048] Actuator 43 further includes actuator signal connection
external terminals designated 258 in the drawings which have
associated therewith tubular connection covers 260, so that
suitable wire connections can be made to actuator signal connection
external terminals 258, with the wire connections desirably passing
through tubular connection covers 260.
[0049] Actuator 43 further includes a pair of lugs 262 which form
the male potion of a preferable quarter turn quick disconnect
assembly which allows actuator 43 to be quickly removed from the
liquid color pump and replaced if need be. A handle 264 is provided
as part of actuator 43 to assist in manual, preferably quarter
turn, rotational movement of actuator 43 to remove it from the
liquid color pump.
[0050] An abutment plug is provided at the top of pin biasing
spring 38, as illustrated in FIG. 11, with a tiny passageway
optionally being provided through abutment plug 266 to facilitate
air passage from the solenoid valve downwardly through actuator 43
into contact with the upper service of a diaphragm portion of a
liquid color pump to which actuator 43 is connected. Alternatively,
air from solenoid valve 70 may pass around the sides of a solid
abutment plug 266, between abutment plug 266 and the annular
interior surface of actuator upper portion 250, to reach the
pumping diaphragm.
[0051] Electrical leads from slide potentiometer 36 that are
internal to actuator 43 are designated generally 268. These leads
extend from potentiometer electrical terminals 270 that are shown
in FIG. 11. An actuator chamber 274 is present within upper portion
250 of actuator 43 with slide potentiometer 36, pin biasing spring
38, and the upper portion of actuator pin 42 all being resident
therewithin, as illustrated in FIGS. 10 and 11. The actuator
chamber 274 present within upper portion 250 of actuator 43 houses
slide potentiometer 36, pin biasing spring 38 and the upper portion
of actuator pin 42. Upon microprocessor 68 actuating solenoid valve
70 to provide a pulse of air via air inlet 44, the air passes
downwardly through inlet 44 into actuator chamber 274 and around
and between pin 42 and the surrounding lower portion 252 of
actuator 43 to escape at the bottom of pin 42 into the pumping
chamber where the air is on the upper side of the pumping diaphragm
of the diaphragm pump.
[0052] O-rings 52 are provided so that in combination with the
quarter turn release mechanism of which lugs 262 are a part, the
actuator upon a quarter turn thereof is in tight facing connection
with the frame portion of the associated pump such that an air
tight seal is created between the lower planar surface 276 of
actuator lower portion 252 and the pumping chamber in which the
diaphragm resides. Once the air applied to the diaphragm has pushed
the diaphragm downwardly, thereby forcing liquid color below the
diaphragm out through the outlet portion of the associated pump, a
strong spring also located in the associated pump pushes the
diaphragm upwardly, back into the neutral position, whereupon
another pulse of air, signaled by the microprocessor and released
by action of the solenoid valve, passes downwardly through actuator
chamber 274 as described above and applies force in the form of air
pressure to the upper side of the pumping diaphragm.
[0053] Actuator chamber 274 is sealed such that air cannot enter
actuator chamber 274 other than through the action of
microprocessor actuating the solenoid valve and providing air in
pulses via air inlet 44. All electrical connections to
potentiometer 36 are provided by potentiometer electrical leads
268, typical ones of which have been illustrated in the drawings.
These potentiometer electrical leads pass through the polymer foam
body of actuator upper portion 250 and are sealed within that
polymer foam body so that no air can enter into actuator chamber
274 other than the air provided by solenoid valve 70.
[0054] While the actuator of the invention has been illustrated in
generally cylindrical form, the actuator may be in any other form
such as with a triangular horizontal cross-section, a rectangular
horizontal cross-section, a hexagonal horizontal cross-section, and
an octagonal horizontal cross-section, etc.
[0055] Gasket 254 provides a tight seal between the upper portion
250 and lower portion 252 of actuator 43. The presence of air
pressure within actuator chamber 274 assures that air will not flow
into chamber 274 other than through air inlet 44 as air provided by
inlet 44 is on its way to the top surface of the pumping
diaphragm.
* * * * *