U.S. patent number 3,781,141 [Application Number 05/161,464] was granted by the patent office on 1973-12-25 for air pressure actuated single-acting diaphragm pump.
This patent grant is currently assigned to Dorr-Oliver Incorporated. Invention is credited to Robert A. Schall.
United States Patent |
3,781,141 |
Schall |
December 25, 1973 |
AIR PRESSURE ACTUATED SINGLE-ACTING DIAPHRAGM PUMP
Abstract
A single-acting fluid pressure actuated diaphragm pump wherein a
high suction lift is attainable by connecting the pump diaphragm to
a piston or auxiliary diaphragm operating in an auxiliary fluid
pressure-actuated chamber connected to the pump housing, and
equipped with a control system for maintaining the pump operating
cycle, which control system in turn is actuated by the pump
diaphragm.
Inventors: |
Schall; Robert A. (Stamford,
CT) |
Assignee: |
Dorr-Oliver Incorporated
(Stamford, CT)
|
Family
ID: |
22581279 |
Appl.
No.: |
05/161,464 |
Filed: |
July 12, 1971 |
Current U.S.
Class: |
417/395; 92/13.8;
92/100; 417/401 |
Current CPC
Class: |
F04B
9/1235 (20130101); F04B 9/127 (20130101); F01L
25/063 (20130101); F04B 43/073 (20130101); F01L
25/08 (20130101) |
Current International
Class: |
F01L
25/06 (20060101); F04B 9/127 (20060101); F01L
25/08 (20060101); F04B 43/06 (20060101); F01L
25/00 (20060101); F04B 9/00 (20060101); F04B
9/123 (20060101); F04B 43/073 (20060101); F16j
003/00 (); F04b 043/00 () |
Field of
Search: |
;417/394,395,398,399,400
;91/314 ;92/100,103 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Husar; C. J.
Assistant Examiner: Smith; Leonard
Claims
I claim:
1. A single acting diaphragm pump system which comprises a pump
housing, a diaphragm dividing the housing into a pumping chamber
having means for pump intake and pump discharge, and a pump
actuating chamber having an opening opposite to, and concentric
with the diaphragm, said actuating chamber having a supply- and
vent connection for introducing into said pump actuating chamber a
fluid pressure medium effective to move the diaphragm to execute
the delivery stroke of the pump, as well as for venting said
actuating chamber during the return suction stroke of the pump,
a pump actuating self-contained power cylinder unit detachably
mounted upon said pump housing concentric with said opening in the
pump housing, and comprising a cylindrical body portion, a top
plate having a vent opening, a bottom plate provided with a central
bottom opening, a piston having a piston rod extending through said
bottom opening, said bottom plate having formed therein a flow
passage communicating with the interior of the cylinder, for
admission of pressure fluid during the pump delivery stroke, and
for venting during the pump return suction stroke,
a sealing device connected to said bottom plate, to provide sealing
relationship between the piston rod and said bottom plate, a set of
external bolt connections between said top plate and said bottom
plate, whereby said cylindrical portion is endwise compressed
between said plates, and a set of anchoring studs for detachably
mounting said power cylinder unit on said pump housing,
and a control system which comprises a first three-way control
valve unit having a valve housing provided with communicating
connections extending respectively to a supply of said fluid
pressure medium, to said auxiliary actuating means and to the
atmosphere, and having a first valve member shiftable in said
housing, said valve member, said housing and said communicating
connections being so constructed and arranged relative to one
another that shifting the valve member in one direction will
condition the valve unit for admitting said fluid pressure medium
to said auxiliary fluid pressure actuated means to execute the pump
filling stroke, and shifting of the valve member in the opposite
direction will condition the valve unit for venting said auxiliary
means during the delivery stroke,
a second three-way control valve unit having a valve housing with
communicating connections respectively to a supply of fluid
pressure medium and to said actuating chamber and to the
atmosphere, and having a second valve member, said valve member and
said housing and said communicating connections being so
constructed and arranged relative to one another, that shifting the
valve member in one direction will condition the valve unit for
admitting said fluid pressure medium to said actuating chamber to
execute the pumping stroke, and shifting the valve member in the
opposite direction will condition the valve unit for venting said
actuating chamber during the pump filling stroke,
and a pilot valve cooperatively associated with said first and
second control valves, and constructed and arranged so as to be
operable to cause the first control valve member to shift in said
one direction while causing the second control valve member to
shift in said other direction, for executing the delivery stroke,
and to cause reversal of the movements of said first and second
control valve members for executing the return stroke of the
pumping cycle,
and an outward extension member for said piston rod provided with
means for engaging said pilot control valve in a manner to operate
said first and second control valve units, for maintaining the
operating cycle of the pump.
2. A single acting diaphragm pump system which comprises a pump
housing, a diaphragm dividing the housing into a pumping chamber
having means for pump intake and pump discharge, and a pump
actuating chamber having an opening opposite to, and concentric
with, the diaphragm, said actuating chamber having a supply- and
vent connection for introducing into said pump actuating chamber a
fluid pressure medium effective to move the diaphragm to execute
the delivery stroke of the pump, as well as for venting said
actuating chamber during the return suction stroke of the pump,
a pump actuating power cylinder unit detachably mounted upon said
pump housing concentric with said opening in the pump housing, and
having a piston and a piston rod extending through a central bottom
opening of the power cylinder into said pump housing, and connected
to the diaphragm,
said power cylinder being in the form of a self-contained unit
which comprises a cylindrical body portion, a top plate having a
vent opening, a bottom plate through which said piston rod extends,
said bottom plate having formed therein a flow passage
communicating with the interior of the cylinder for admission of
pressure fluid and for venting, a sealing device connected to the
underside of said bottom plate, to provide sealing relationship
between the piston rod and said bottom plate, thereby sealing the
cylinder and the pump housing relative to each other, a set of
external bolt connections between said top plate and said bottom
plate, whereby said cylindrical portion is endwise sealingly
compressed between said plates, with a set of anchoring studs
provided for detachably mounting said power cylinder on said pump
housing,
and a control system for maintaining the pumping cycle, which
comprises
a. separate main control valve means movable in one direction to
admit pressure fluid into said pump actuating chamber while
allowing said power cylinder connection to be vented, and movable
in the opposite direction to admit pressure fluid into said power
cylinder, while allowing said actuating chamber to be vented,
b. actuator means supported by said cylinder, and cooperatively
associated with said piston rod, as well as operatively connected
to said separate main control valve means for moving the same in
alternate directions incident to the reciprocations of the piston
rod,
c. and an outward extension member for said piston rod, provided
with means for engaging said associated actuator means in a manner
to operate said control valve means, for maintaining the operating
cycle of the pump.
3. The pump system according to claim 2, wherein said control
system comprises a main plug valve unit having a pressure fluid
supply connection, and having a reciprocable main plug valve
member, operatively connected to said actuating chamber and to said
pressure fluid-actuated auxiliary means, so that said main plug
valve member when moved to one end position will allow pressure
fluid to pass to said actuating chamber, while a vent connection is
established with said auxiliary fluid pressure-actuated means, and
that said main plug valve member when moved to the opposite end
position will cause the flow through said main plug valve unit to
be reversed,
said control system further comprising a pilot plug valve unit
having a pressure fluid supply connection, and a reciprocable pilot
plug valve member, operatively connected to said main plug valve
unit, so that moving the pilot plug valve member by said extension
member in one direction will admit fluid pressure through said
pilot valve unit to said main plug valve unit, effective to move
the main plug valve member in one direction, and that moving the
pilot plug valve member by said extension member in the opposite
direction will cause said main plug valve member to move in the
opposite direction.
Description
This invention relates to a diaphragm pumps and pumping systems
embodying a diaphragm pump. Such pumps are well suited and reliable
for handling sludges and slurries, for example, sewage sludges and
metallurgical pulps. These volumetrically effective displacement
pumps are relatively immune to wear and tear by the slurry solids,
and are self-priming when installed with a negative suction head.
Also, their capacity and mode of operation are readily adjustable
by adjusting the length and/or frequency of the pumping stroke.
Thus the diaphragm pumps, as a class, are distinct from rotary
pumps such as centrifugal pumps or Moyno pumps or other rotating
pumps which as a class are subject to wear and tear due to the
rotation of the parts and the sealing means required, especially
where abrasive materials are being handled.
More in particular, this invention relates to fluid
pressure-actuated diaphragm pumps wherein a diaphragm divides the
pump housing into a pumping chamber at one side of the diaphragm
and a pump actuating chamber at the opposite side thereof. In a
conventional diaphragm pump of this type, the pumping -- or
delivery stroke is effected by means of a fluid pressure medium
such as air admitted into the actuating chamber, which moves the
free floating diaphragm so as to displace the contents of the
pumping chamber against a pumping head. Thus, diaphragm stresses
are compensated irrespective of the height of the pumping head.
The return stroke may be effected either by gravity filling of the
pump chamber under positive suction head, while the actuating
chamber is being vented, or else by the application of vacuum to
the actuating chamber for effecting or assisting the return stroke
of the pumping cycle. The vacuum facility although costly to
provide and operate, is nevertheless limited in its effectiveness.
A control system usually including a timing device regulates the
admission of the pressure fluid alone, or the admission of the
pressure fluid alternating with vacuum where the pump chamber is to
operate with a negative suction head.
The diaphragm pumps, while stress-compensated in that they avoid
high diaphragm stresses during the pumping stroke, are somewhat
sluggish especially where a negative suction lift with the
aforementioned vacuum assist is involved. Consequently, their
capacity is relatively limited due to the time-consuming character
of the operating cycle which in the case of negative suction lift
operation, and with air as the pressure medium, comprises:
A. ADMISSION, BUILD-UP, AND MAINTAINING OF PRESSURE IN THE
ACTUATING CHAMBER TO EFFECT THE PUMPING STROKE,
B. VENTING THE AIR PRESSURE CHAMBER TO THE ATMOSPHERE AT THE END OF
THE PUMPING STROKE,
C. ADMISSION, BUILD-UP, AND MAINTAINING OF VACUUM INSTEAD OF AIR
PRESSURE IN THE ACTUATING CHAMBER, TO EFFECT THE PUMP-FILLING
STROKE, AND
D. AGAIN VENTING THE CHAMBER TO THE ATMOSPHERE IN PREPARATION FOR
THE NEXT PUMPING CYCLE.
The conventional diaphragm pumps operating in this manner are
therefore relatively sluggish especially in the handling of sludges
of higher densities and/or viscosities, yet they provide a
relatively smooth and cushioned operating cycle due to the gradual
transition from one stroke to the next, a characteristic that is
lacking in the mechanically actuated class of diaphragm pumps.
Diaphragm pumps of the class that are wholly mechanically or
positively actuated, although requiring only a power supply for
their operation, suffer from the disadvantage that the diaphragm
due to its positive mechanical connection to a reciprocating drive,
is subject to a combination of high shearing, bending, and tension
stresses in the operation of the pumping cycle, especially so when
operating against a high pumping head. These stresses are
aggravated by the uncushioned reversal of the forces affecting the
diaphragm at the end of the respective strokes of the pumping
cycle. This in turn limits diaphragm life, as well as discharge
head capability. Such stresses then lead to shutdowns and the need
for replacing the diaphragm when destruction thereof is imminent or
has occurred.
Thus, maximum stresses in the diaphragm occur during the pumping
stroke when the actuating rod acting like a punch upon the central
portion of the diaphragm, must push against the full pumping head
which may be in the order of, say, 100 ft. By comparison, the
average diaphragm stresses developing during the return -- or pump
filling stroke with negative suction lift are much smaller, namely
a fraction of the 34 ft. maximum lift as determined by the
atmospheric pressure. A practical average suction lift frequently
required may be in the order of 10 to 12 ft., as compared with a
pumping head that may be, say, 10 times that much.
Another drawback of the mechanically actuated diaphragm pump lies
in the fact that the diaphragm bending stresses are aggrevated due
to the abrupt stress reversal occurring at the end of each stroke,
and furthermore due to mass action stresses, if the pumping speed
should be increased.
In view of the foregoing criteria of conventional machines, it is a
general object to provide an improved diaphragm pump that is free
from the essential drawback of the aforementioned two groups of
diaphragm pumps.
Consequently it is among the more specific objects to provide a
fluid pressure-actuated diaphragm pump
which avoids the high diaphragm stresses of the mechanically
actuated diaphragm pump;
which is capable of substantial capacity increase through higher
speeds at minimum wear and tear on the diaphragm;
which overcomes the sluggishness and capacity limitations of the
fluid pressure-actuated diaphragm pump, while maintaining the
cushioning effects in the operating cycle, whereby excessive
diaphragm stresses are avoided even at increased pumping
speeds;
which is operable at a negative suction head higher than was
heretofore practically feasible, to an extent approaching the
atmospheric limit;
which has simple controls for the adjustment of pumping speed,
capacity, and stroke while the pump is in operation;
which is operable without the use of the conventional vacuum
assist, against any desired negative suction head within the
atmospheric limit;
and which is economical to operate, requiring only a supply of
fluid pressure medium.
Another object is to provide means for converting a fluid
pressure-actuated diaphragm pump arranged for operation with
positive -- or gravity suction head, into one capable of negative
suction lift operation, while utilizing a pressure fluid supply
instead of vacuum.
Another object is to provide means for substantially increasing the
capacity of fluid pressure-actuated diaphragm pumps irrespective of
whether or not they operate with gravity -- or negative suction
head.
Still another object is to provide a diaphragm pump of great
versatility, applicable to a large spectrum of operating conditions
and requirements relative to capacity, pumping discharge head, and
suction head.
To attain the foregoing objectives, the invention provides a fluid
pressure-actuated diaphragm pump provided with a fluid
pressure-actuated auxiliary actuating device connected to the
diaphragm, and operable in such a manner that the fluid pressure
applied to the auxiliary device will impart to the diaphragm a
positive suction lift stroke, whereupon fluid pressure applied to
the diaphragm will effect the pump delivery stroke. The fluid
pressure effecting the suction stroke, and the fluid pressure
effecting the pump delivery stroke, are applied in alternation
automatically through a control system governed by the
reciprocating movement of the diaphragm.
In one embodiment illustrating the invention, the auxiliary
actuating device is in the form of an actuating cylinder unit
mounted upon the pump housing, with the piston rod coaxially
connected to the diaphragm.
In another embodiment, the auxiliary actuating device comprises a
second diaphragm concentric with the pump diaphragm, and a
force-transmitting rod inter-connecting the centers of the two
diaphragms.
The operating air pressure for effecting both the suction stroke
and the delivery stroke may be derived from a single source of
supply, although the pressures admitted to the actuating device and
the pumping chamber respectively, may be individually controlled.
Thus it is a highly practical feature that the pumping speed is
adjustable simply by controlling the operating pressures without
stopping the operation of the pump.
Other features lie in the arrangement and details of the system
that controls the pumping cycle, and maintains continuous pump
operation.
Other features are found in the structural combination of the pump
housing with an actuating cylinder unit.
Other features lie in the combination of the pump housing with the
actuating cylinder, and with the control system.
Other features and advantages will hereinafter appear.
As this invention may be embodied in several forms without
departing from the spirit or essential characteristics thereof, the
present embodiment is illustrative and not restrictive. The scope
of the invention is defined by the appended claims rather than by
the description preceding them, and all embodiments which fall
within the meaning and range of equivalency of the claims are
therefore intended to be embraced by those claims.
FIG. 1 is a vertical sectional view of the diaphragm pump according
to one embodiment of this invention, showing the mounting of the
auxiliary actuating device in the form of an actuating cylinder
unit, with the piston rod extending into the pump housing in
sealing relationship therewith.
FIG. 2 is a cross-sectional view taken on line 2--2 of FIG. 1.
FIG. 3 is a top view taken on line 3--3 in FIG. 1.
FIG. 4 is an enlarged detail view taken from FIG. 1, clearly
showing the sealing means for the piston rod.
FIG. 5 is a schematic view of the diaphragm pump of FiG. 1, showing
one embodiment of a control system of fluid actuated valves for
maintaining the pumping cycle controlled by the movement of the
diaphragm, in condition for the pump delivery.
FIG. 6 is a schematic view showing the control system of FIG. 5
conditioned for the pump filling or return stroke of the pumping
cycle.
FIG. 7 is a schematic view of another embodiment of the pump
operating control system employing solenoid-actuated control
valves, conditioned for the pump delivery phase.
FIG. 8 is a schematic view showing the control system of FIG. 7,
conditioned for the pump filling return stroke of the pumping
cycle.
FIG. 9 is a detail view showing another embodiment of the solenoid
actuated valve of FIGS. 7 & 8.
FIG. 10 shows schematically the diaphragm pump in another
embodiment of the invention, using an actuating diaphragm instead
of the cylinder unit.
FIGS. 11 and 12 are schematic views similar to FIGS. 5 and 6,
showing another embodiment of the control system, with the pumping
cycle controlled by the movement of the diaphragm.
FIGS. 13 and 14 show a control system similar to FIGS. 11 and 12,
actuated by the movement of the diaphragm, although functionally
limited to gravity pump intake operation.
The diaphragm pump of this invention, as exemplified in the
embodiment of FIG. 1, comprises as main component sections a pump
housing 10 having inlet and outlet connections 11 and 12 at the
bottom provided with inlet and outlet check valves 11a and 12a
respectively (see FIGS. 5 and 6), an actuating cylinder unit 13
mounted upon the top of the housing coaxial therewith, and a
control box 14 mounted atop the actuating cylinder unit, which
control box is part of a control system for maintaining the pumping
cycle. The control system itself is shown in the schematic FIGS. 5
and 6.
The pump housing contains a pump diaphragm 15 of suitable flexible
material, which diaphragm is peripherally clamped between a lower
housing section 16 and an upper housing section 17 as indicated by
the bolt connections 18. The diaphragm thus divides the housing
into a lower pumping chamber 19 communicating with said pump inlet
and pump outlet connections, and an upper pump actuating chamber
20. This chamber 20 has a pipe connection 21 whereby a fluid
pressure medium is admitted to execute the pumping stroke, and
through which the chamber is vented during the return stroke of the
pumping cycle, all as will be furthermore described below in
connection with the control system of FIGS. 5 & 6.
The diaphragm has a central opening 22 closed by a pair of circular
clamping plates 23 & 24 tightly engaging the inner beaded edge
25 of the diaphragm. The pumping chamber is shown to be provided
with protective or abrasion resistant rubber -- or composition
lining 26 covering the lower housing section, and a coating of
similar material 26a on the exposed surfaces of the lower clamping
plate 23.
The clamping plates are positioned relative to each other by
locating pins 27, and are held together by screw bolts 28a.
The screw bolts are threaded into the lower clamping plate 23 with
their heads 28a located adjacent to and preferably countersunk in
the upper clamping plate, and preferably countersunk therein as
shown in FIG. 1. The upper clamping plate is rigidly although
detachably connected to an actuating rod 29 by means of a screw
bolt 28b threaded into the lower end of the rod coaxial therewith.
In this way, all fastening bolts in the clamping plate assembly are
protected from contact with the contents of the pumping chamber,
thus allowing the lower clamping plate to present an unbroken
surface "S" which may be coated with a protective material similar
to the lining of pump chamber. This coating provides a cushion when
contacting the lining of the pump housing at the lower end of the
delivery stroke. It is also noted that the coating on the lower
clamping plate will remain undisturbed in case the clamping plates
are to be dismounted.
The piston rod 29 rigidly connected to the clamping plate assembly,
extends upwardly through an opening 30 in the upper housing
section, and into the actuating cylinder unit 13 concentric with
the housing.
The actuating cylinder unit 13 comprises a straight cylindrical
member 30a endwise confined between a bottom plate 31 and a top
plate 32, all in concentric relationship to one another, as well as
concentric with the axis of the pump housing. The parts
constituting the cylinder are held together tightly by means of tie
rods 32a threaded into the bottom plate 31 (see FIGS. 2 & 3).
This cylinder assembly is detachably fixed to the upper housing
section 17 by means of screw bolts 33 (see FIG. 2).
This cylinder assembly contains a piston 34 fixedly connected to
the upper end of piston rod 29 which extends downwardly from the
piston through an opening 36 in the bottom plate, and also through
the opening 30 in the pump housing. The lower end of the piston rod
is rigidly connected to the clamping plate assembly on the
diaphragm, by means of the detachable bolt connection 28b concealed
between the two clamping plates, and thus protected against contact
with the material being handled by the pump.
A pipe connection 39 through a radial bore 40 in the bottom plate
31 provides communication between the interior of the actuating
cylinder and the control system of FIGS. 5 & 6, whereby fluid
pressure medium is admitted into the cylinder to execute the pump
filling -- or return stroke of the pumping cycle, and whereby the
cylinder may also be vented to the atmosphere during the pump
delivery stroke of the cycle.
A sealing device 41 surrounds the piston rod, connected to
underside of bottom plate 31 of the cylinder assembly. The sealing
relationship thus established between the piston rod and the pump
housing is required in order to contain the fluid pressure in the
pump actuating chamber 20 while the cylinder is being vented during
the pump delivery stroke, and conversely to contain fluid pressure
in the cylinder while the pump actuating chamber is being vented
during the pump filling return stroke of the cycle. Referring to
the detail of FIG. 4, the sealing device comprises an upwardly
directed sealing ring 42 and a downwardly directed sealing ring 43,
both being retained in an annular holder 44 bolted to the underside
of bottom plate 31 of the cylinder assembly.
An extension -- or actuating rod 45 extends upwardly from the upper
end of the piston rod, and through an opening 46 in top plate 32
into the control box 14. This actuating rod has mounted thereon a
pair of vertically spaced trip members or stop members 47 and 48
each of which is adjustable along the rod. The rod may be in the
form of a threaded element, and the stop members in the form of
nuts.
With these nuts or stop members in properly adjusted position on
the rod, it will be shown that at the end of each stroke of the
pumping cylce, a respective stop member will actuate a control
member 49, thereby causing the control system of FIGS. 5 and 6 to
initiate a pump stroke in the opposite direction.
Briefly then, the operating cycle of the pump as governed by the
setting of the stop members 47 & 48 moving with the piston rod,
is as follows:
Fluid pressure admitted through pipe 39 into actuating the
cylinder, will move the piston together with the diaphragm to the
upper end position of the pump filling -- or pump suction stroke
(see FIG. 1), while the actuating chamber 20 is being vented
through pipe connection 21. At this point, the lower stop 47 on the
extension rod will have thrown the control member 49 in the control
box 14 to a position causing the associated control system (FIGS. 5
& 6) to admit fluid pressure through pipe 21 into the pump
actuating chamber 20, while allowing the actuating cylinder to be
vented through pipe 39. This fluid pressure continues until the
diaphragm together with the piston will have reached their lower
end position of the pump delivery stroke, indicated in dot-and-dash
(See FIG. 1). At this point, the upper stop 48 on the extension rod
will have thrown the control member 49 in the control box to the
opposite position causing the associated control system (FIGS. 5
& 6) to again admit fluid pressure to the actuating cylinder
through pipe 39, while allowing the actuating chamber to be vented
through pipe 21, thereby completing the pump operating cycle.
In the control system itself, as implemented according to the
embodiment of FIGS. 5 and 6, a first control valve 50 communicating
with the actuating cylinder through pipe 39, is operable to admit
fluid pressure during the pump filling stroke, and to vent the
cylinder during the pump Delivery stroke. For that purpose, the
valve unit 50 has a plug valve member 50a normally urged by a coil
spring 50b into the FIG. 5 position whereby a vent connection 50c
is established between the actuating cylinder and the atmosphere,
as indicated by flow arrows A-1. But when this valve member 50a is
moved or depressed against spring pressure from the FIG. 5 to the
FIG. 6 position, it will establish a connection 50d for fluid
pressure supply to the cylinder as indicated by flow arrows A-2,
while a vent connection 50c is closed.
A second similar control valve unit 51 communicating with the pump
actuating chamber through pipe 21, is operable to admit fluid
pressure through pipe 21 during the pump delivery stroke.
For that purpose, the valve unit 51, has a plug valve member 51a
normally urged by coil spring 51b into the FIG. 6 position, whereby
a vent connection 51c is established between the actuating chamber
20 and the atmosphere, as indicated by flow arrows A-3. But when
this valve member 51a is moved or depressed against spring pressure
into the FIG. 5 position, it will establish a connection 51d for
pressure supply to the actuating chamber, as indicated by flow
arrows A-4 in FIG. 5.
With the foregoing in mind, the cyclic operation of the control
system will be understood by reference to FIGS. 5 and 6, as
follows:
The operation of the two control valve units 50 and 51 in properly
timed relationship to each other is governed by a pilot valve unit
52 located in the control box atop the actuating cylinder. The
reciprocating piston 34 through stops 47 and 48 and control member
49 will shift a plug valve member 53 in the pilot valve unit
between the positions of FIG. 5 and FIG. 6 at the end of each
piston stroke.
Thus, the pilot valve passes fluid pressure or air pressure (see
flow lines A-5) from a source or pipe 54 through pipe 55 to the
second control valve unit 51, thereby holding the plug valve member
51a depressed against spring 51b. In this position, the valve
member 51a keeps the vent connection 51c closed, while passing
fluid pressure or air pressure (see arrows A-4) from a source or
pipe 57 and through a pipe 21 into the actuating chamber 20.
At the same time, the FIG. 5 position of the pilot plug valve
member 53 will, through a port 58 in the valve member, and through
a pipe 59, establish a vent connection 59a with the first control
valve unit 50 as indicated by flow arrows A-6. This allows spring
50b to hold the plug valve member 50a biased in the FIG. 5
position, which in turn establishes the vent connection 50c (see
arrows A-1) with the actuating cylinder.
Thus, as the piston and diaphragm under fluid pressure from the
actuating chamber reach the lower end position of the pump delivery
stroke, the upper stop 48 engaging the control member 49 will shift
the pilot valve member 53 from the FIG. 5 to the FIG. 6 position.
Consequently, fluid pressure or air pressure from pipe 54 will now
act through the pilot valve unit and pipe 59 (see flow lines A-7)
upon plug valve member 50a, holding the same depressed against the
spring 50b, whereby fluid pressure or air pressure is admitted from
supply pipe 50d through control valve 50 and transfer pipe 39 into
the actuating cylinder, while the vent connection 50c is
closed.
At the same time, a port 60 in the pilot valve member will, through
pipes 55 and 61 establish a vent connection (see flow lines A-8) to
the second control valve unit 51, allowing the spring 51b to move
the plug valve member 51a from the FIG. 5 to the FIG. 6 position.
This in turn establishes and maintains a vent connection from pipe
51c to the actuating chamber 20 (see flow lines A-3), until the
piston and diaphragm under fluid pressure in the cylinder, reach
the upper end of the pump filling -- or return stroke. At this
point, the lower stop 47 engaging the control member 49, will shift
the pilot plug valve member back to the FIG. 5 position, thereby
initiating the next pumping cycle. The control member 49 may be in
the form of a flexible finger or blade, to allow for a slight
overrunning of the stops 47 and 48 in the reciprocation of the
extension rod.
The supply of fluid -- or air pressure through the control system
to the pump as shown in FIGS. 5 and 6 is provided from a main
supply pipe 62. A branch pipe B-3 leading from the main supply pipe
62 supplies the pilot valve unit 52 with the fluid -- or air
pressure required for the operation of the control valve units 50
and 51. Branches B-1 and B-2 of the pipe 62 supply the control
units 50 and 51 respectively. Advantageously, each of these
branches is provided with a constant pressure control valve, which
valves are designated as P-1 and P-2 respectively. These constant
pressure control valves are of a kind that will hold the pressure
on the control valves 50 and 51 constant at an adjustable
magnitude, and they may be identified as Norgren Pressure
Regulators No. 11-024-0008. In this way, the actuating chamber and
the actuating cylinder may be operated at different adjusted
pressures. The respective pressures may be raised or lowered,
thereby varying the pumping speed or pump delivery rate, without
stopping the operation of the pump.
Furthermore, by varying the setting of the stops 47 and 48 on the
extension rod, one may vary the length of the pumping stroke, or
varying the position of the upper stop alone.
By combining the pressure adjustments with the stroke adjustments
in the control system of this invention, a wide range of pump
operating requirement can be met.
Hand controlled shut-off valves V-1, V-2, V-3 and V-4 may be
provided in the main supply line 62, and in the branches B-1, B-2
and B-3 respectively.
A modification of the pump control system as shown in FIGS. 7 and 8
is functionally equivalent to the system shown in the above
described FIGS. 5 and 6 representing the control of the operating
cycle. Accordingly, the operating conditions shown in FIG. 7 and
FIG. 8 correspond to the conditions shown in FIG. 5 and FIG. 6
respectively.
The difference is due to the fact that the pilot valve unit 52 is
replaced by an electrical switch box S, while the air
pressure-actuated control valves 50 and 51 are replaced by a pair
of solenoid-actuated control valves C-1 and C-2. The switch member
M is engaged alternatingly by stops 47 and 48 in the same manner as
the control member 49 in FIG. 5.
Thus, with the switch in the FIG. 8 position, a current from a
power supply 63 keeps a solenoid L-1 energized, thereby keeping a
pilot plug valve member 64 in a retracted position against the
pressure of a spring 65. The pilot valve member thus closes a vent
connection 66, while allowing air pressure from pipe 67 acting
through passages 68, 69 and 70 to keep a main plug valve member 71
in a position whereby the air pressure is admitted to the actuating
cylinder unit through transfer pipe 71a, thus executing the upward
pump filling -- or suction stroke.
At the same time, the FIG. 8 switch position keeps a solenoid L-2
of valve unit C-2 de-energized, thereby allowing a spring 72 to
keep a pilot plug valve member 73 in a position whereby a vent
connection 74 is kept open, but passage 75 is closed. Thus, air
pressure from pipe 76 acting through passage 77 keeps a main plug
valve member 78 in a position whereby a vent connection is
established with the pump-actuating chamber 20 by way of vent 79,
valve passage 80 and transfer pipe 81.
At the end of the upward pump filling stroke, when the lower stop
47 has thrown the switch member M to the FIG. 7 position, the
condition of the solenoids L-1 and L-2 is reversed rendering
solenoid L-1 de-energized and solenoid L-2 energized, thereby
initiating the downward pump delivery stroke, as indicated by the
various flow arrows in FIG. 8.
FIG. 9 represents a modification of the solenoid-actuated control
control valves of FIGS. 7 and 8, in that solenoids are directly
connected to respective main plug valve members of the conrol valve
units.
In another embodiment of the invention according to FIG. 10, the
auxiliary actuating device connected to the pump housing and pump
diaphragm, comprises an auxiliary pressure-actuated diaphragm
instead of the cylinder unit shown in the embodiment of FIG. 1. The
pump section 81a itself may remain unchanged, having an actuating
chamber 81b and pump delivery chamber 81c on respective sides of
the pump diaphragm, and having a connection 81d for admitting air
pressure to the actuating chamber during the pump delivery stroke,
and for venting the actuating chamber during the pump intake
stroke.
Accordingly, a connecting rod 82 connects the clamping plates of
the pump diaphragm with similar circular clamping plates 83 and 84
of an auxiliary diaphragm 85. These clamping plates fit over a
reduced upper threaded end portion 86 of the connecting rod,
secured by a nut 86a. A rod extension 87 of the length E, and
preferably of the same diameter as connecting rod 82, has internal
thread at its lower end, engaging the threaded upper end of the
connecting rod, and tightened against nut 86a as by means of flat
faces 88.
The auxiliary diaphragm 85 is contained in an auxiliary diaphragm
housing 89, clamped between the lower housing section 90 and the
upper housing section 91. The auxiliary diaphragm housing is
connected to the pump housing by means of screw bolts or studs 85a
arranged internally of the housing. The auxiliary diaphragm thus
divides the housing 89 into a lower auxiliary actuating chamber 92,
and an upper chamber 93 which is permanently vented at 93a. The
lower chamber has a connection 94 communicating with the control
system, for supplying air pressure during the suction stroke, and
for venting the chamber during the pump delivery stroke.
The connecting rod 82 extending through the bottom 95 of the
auxiliary diaphragm housing, is surrounded by a sealing device D
similar to the one shown in FIGS. 1 and 4, attached to the
underside of bottom 95.
The rod extension 87 is guided in the top portion 96 of the
diaphragm housing, and has an upwardly extending coaxial auxiliary
rod 97 carrying a pair of vertically spaced adjustable stops or
nuts 98 and 99 engaging a control member 100 in control box 101 at
the end of each stroke of the pumping cycle, thereby actuating the
control system in the manner previously described in connection
with FIGS. 1, 5 and 6.
The rod 82 is guided in sealing device D.
Another embodiment of the control system as shown in FIGS. 11 and
12 differs from the system of FIGS. 5 and 6, in that a single main
plug valve unit 102 takes the place of the two main control valve
units of FIGS. 5 and 6. This single main control valve unit 102 is
actuated by an auxiliary -- or pilot plug valve unit 103 actuated
by the reciprocations of the extension rod.
FIG. 11 illustrates the condition of this control system during the
pump suction -- or pump filling stroke. Accordingly, the pilot plug
valve member 103a is positioned so that air pressure from supply
line 104 passing through the pilot valve and pipe 105 has moved the
main plug valve member 102a to a position where air pressure from
supply line 106 passing through the main valve and through pipe 107
acts upon the piston 34 moving the same upwardly until it in turn
through the extension rod 45 moves the pilot plug valve member to
the FIG. 12 position. During this pump suction stroke the pilot
valve unit has an open vent connection 108, while the main valve
unit has an open vent connection 109.
FIG. 12 illustrates the condition of this control system during the
pumping -- or pump delivery stroke. Accordingly, the pilot plug
valve member 103a is positioned so that air pressure from supply
line 104 passing through the pilot valve and pipe 110 has moved the
main plug valve member 102a to a position where air pressure from
supply line 106 passing through the main valve and through pipe 111
acts upon the pump diaphragm 15 moving the same downwardly against
the pump delivery head, until the extension rod 45 again reverses
the position of the pilot plug valve member. During this pump
delivery stroke the pilot valve unit has an open vent connection
112, while the main valve unit has an open vent connection 113.
In a comparison of the embodiments of the control systems of FIGS.
5 and 11 respectively, it may be seen that the springs 50b and 51b
in the twin control valve arrangement of FIG. 5 produce a
relatively snappier or more instantaneous movement of the
respective plug valve members 50a and 51a, over the single control
valve arrangement in FIG. 11, whereas the single control valve 102
may have the advantage of greater simplicity and lower cost.
The two identical air pressure actuated control valve units 50 and
51 in the FIGS. 5 and 6 embodiment are available from Mac Valves
Inc., Detroit, Michigan, Model 4444. The pilot valve unit 52 in the
same embodiment is available from In-Val-Co., Tulsa, Oklahoma,
Model No. 416EF1.
The two identical solenoid-actuated control valve units C-1 and C-2
in the FIGS. 7 and 8 embodiment, are available from Mac Valves
Inc., Detroit, Michigan, Model 4624C.
The single air-actuated control valve 10 in the FIGS. 11 and 12
embodiment is available from Mac Valves Inc. Detroit, Michigan,
Model 2733, while the pilot valve unit 103 is Model 1807-1-07 from
the same source.
The feature of controlling the valve system and thereby the pumping
cycle, from the movement of the diaphragm itself, is further
illustrated in FIGS. 13 and 14 which differ from respective FIGS.
11 and 12 in that the pumping cycle operates with the pump located
for gravity feed supply to the pumping chamber.
As represented in FIGS. 13 and 14, this pumping cycle operates as
follows:
In this embodiment, the pump body or housing 114 is divided by a
diaphragm 115 into a pumping chamber 116 and a pump actuating
chamber 117. The central opening 118 of the diaphragm is closed by
a pair of circular clamping plates 118a and 118b such as described
above in connection with FIG. 1. A rod 119 is fixed to, and
extending rigidly from the center of the clamping plates through
the actuating chamber 117, is guided in a pair of bushings 120 and
121 mounted in a guide member 122 having a flange connection 123
with the pump body. The lower bushing 121 contains a seal 121a
surrounding the rod, and effective to contain air pressure supplied
to the actuating chamber 117.
A pilot valve unit 124 is identical to the one in FIGS. 11 and 12,
and is similarly actuated by an extension rod 125, to operate a
control valve unit 126. Accordingly, at the end of a downward
pumping stroke, with the pilot valve member 127 in the FIG. 13
position, air pressure from supply line 128 and branch line 129,
will have reached the left hand end of the control valve 126 via a
passage 130 in the pilot valve and a transfer pipe connection 131,
and will have moved the control plug valve member 132 to its right
hand end position. In this FIG. 13 condition of the two plug valve
members, the actuating chamber 117 is being vented through transfer
pipe 133 and passage 134 in the control valve unit, thus allowing
gravity pump feed to fill the pumping chamber 116, moving the
diaphragm to its upper end position (see arrow B-1).
At the end of this upward pump filling stroke, the stop member 135
through bridge member 136 will move the pilot plug valve member 127
to the FIG. 14 upper end position, allowing fluid pressure from
branch line 129 via passage 137 in the pilot valve and transfer
pipe 133a to move the control plug valve member 132 to its left
hand end position. In this FIG. 14 condition of the two plug valve
members, fluid pressure from branch supply pipe 129a will reach the
pump actuating chamber 117 via passage 138 in the control valve
unit and transfer pipe 133, initiating the downward pump delivery
stroke of the diaphragm (see arrow B-2). At the end of this pump
delivery stroke, the position of the two plug valve members will be
reversed by stop member 135a, thus initiating the next pumping
cycle.
In the FIG. 13 condition, it will be seen that the right hand end
of the control valve unit 126 is vented via transfer pipe 133a and
passage 138 in the pilot valve. In the FIG. 14 condition it will be
seen that the left hand end of the pilot valve is vented via
transfer pipe 131 and passage 139 in the pilot valve. A constant
pressure control valve 140 is shown in branch supply pipe 129a.
Hand operated valves 141, 142, and 143 fluid pressure supply pipes
are similar to those shown in FIGS. 11 and 12.
* * * * *