Note: Descriptions are shown in the official language in which they were submitted.
BACKGROUND OF THE INVENTION
This invention relates to a pneumatically-
operatcd diaphragm pump utilized in a Post-mix
beverage syrup dispensing system and more specifically
to a reciprocating pump including a spring actuated
reversing means for reversing the direction of a
reciprocating pump at the end of its respective
strokes.
Diaphragm pumps are widely used particularly for
pumping liquid so~utions and highly viscous materials
and are frequently,used under conditions such that
the viscosity of the fluid being pumped, the head of
the suction side of the pump and the back pressure on
the pump discharge may all vary as conditions under
which the pump is operating vary. The speed of such
pumps has generally been controlled by inserting an
adjustable valve in the air line leading to ~he pump,
However, this approach, requires that the operation
of the pump be kept under continuous obserYation and
the valve adjusted ~o suit Yarying conditions, otherwise
the speed of the pump w;ll vary substantially depending
upon the conditions of operatior~. For example, if the
back pressure on the pump should increase or decrease
--2--
for any particular reason, or if the viscosity of the
liquid being pumped should vary, then the speed of operation
and the quantlty of liquid being pumped per unit of time
will accordingly be affected. Therefore, it is hiyhly
S desirable that the pump be controlled such tha-t i-t operates
at a substantially constant speed under varying conditions.
Furthermore, it is essential that the en-tire pumping cycle
be completed so as to ensure continuous delivery of the
medium being pumped at a constant consistency or concentra-
-tion. In order to ensure the latter, means have been
suggested such as disclosed in ~. S. Patent 4,008,984
wherein opposed coil springs are provided for assisting
the respective valve member in -the completion of its
pumping cycle. The coil compression springs of identical
force under the pressurized gas system assist in completion
of the pumping cycle first in one direction, and then by
asserting a positive reversing effect when either of the
springs becomes fully compressed. Although providing a
reversing mechanism for the double acting pump disclosed,
there are inherent disadvantages with such a system. For
example, if for some reason the pressurized system is
effected in such a ~ay that a back pressure is created or
established so as to inhibit or reverse the pumping
cycle before it is completed, there is no means for over-
coming the undesirable effect, and the fully compressedstate of the spring is not reached. I'hus, it is possible
that the pumping cycle cou]d be reversed regardless of the
presence of the compression springs, before the cycle is
completed, thus effecting the efficiency, if not the
complete purpose, of the reciprocating pump.
It is, therefore, an object of an aspect of the present
invention to provide a reciprocating diaphragm pump for deliver-
ing under constant pressure, syrup to a Post-mix beverage
dispensing systern which will overcome the above noted
disadvantages.
It is an object of an aspect of the present invention
to provlde a double-acting reciprocating pump for syrup
in a Post-mix beverage dispensing system wherein a
reversing means is provided for reversing the direction
of the purnp at the end of each respective stroke.
An object of an aspect of the present invention is to
provide a gas-operated diaphragm pump including a
specialized valve, actuated by a springloaded member
attached to a common shaft, which alternates the supply
of pressurized gas to the respective diaphragms.
An object of an aspect of the present invention to
provide a double-acting reciprocating pneumatic pump for
dispensing syrup to a dispensing outlet wherein the pump
cycle reversing system includes a snap-acting reversing
means which ensures the completion of -the pumping cycle
and precludes the sticking of the pneumatic reversing
mechanism in an in-termediate position.
An object of an aspect of the present invention
is to provide a pneumatic double-acting reciprocating
pump having a reversing system which includes a valve,
a valve actuating member, and a snap-acting spring
member which reliably directs the supply of pressurized
gas to the surface of either one of the two diaphragms
in a cyclic manner.
An object o-f an aspect of the present invention is to
provide a reciprocating pneumatic diaphragm pump
including a reversing rneans which allows for the dis-
persing of fluid from either one of two diaphragmchambers at the respective ends of -the pump in a
systematic, controlled manner.
Other objects and further scope of applicability of
the present invention will become more apparent from
". . . .
--4--
the detailed description given hereinafter. It
should be understood, however, that the detailed
description and accompanying drawings, while
indicating preferred embodiments of the present
invention, are given by way of illustration only
since various changes and modifications within the
spirit and scope of the invention will become apparent
to those skilled in the art. Any such changes and
modifications should be considered to be within the
scope of this invention.
SUM~IARY OF THE INVENTION
The foregoing objects and others are accomplished
in accordance with the present invention generally
speaking by providing a pumping device comprising a
pair o~ flexible diaphragms mounted on the respective
ends of a common shaft. The outer surface of the
diaphragms are in contact with the liquid tc be
dispensed by the system, more particularly syrup for a
Post-m;x beverage dispensing system. The chamber
within the pump housing contains an inner wall in
which passages are provided for directing compressed
air, introduced into the reciprocating pump, to the
surfaces of the diaphragms. The flow of air is
controlled by a reversing valve adapted so as to
redirect the flow of compressed air to the respective
diaphragm at the completion of each stroke of the
pump in a cyclic manner. A valve actuating member
or yoke is provided which engages the shaf~ within the
inner chamber of the pump housing and travels with
the pumping action of the shaft. The yoke i5 designed
so as to engage the reversing valve during the terminal
phase of the pumping stroke, thus activating the valve
~ -5~
and reversing the piston action of the pump. To
complete the pump reversing system, a snap-act;ng spring
actuating means interconnected with the yoke of the
shaft, is centered within the inner chamber of the
housing of the pump, pivotably mounted beneath the
shaft connecting the diaphragms. The valve is provided
with O-rings positioned within the valve body with
respect to the air passages oE the valve such that
during the first half of the reciprocating cycle,
pressurized gas is introduced through the respective
passageways and directed to the air chamber of one of
th diaphragms. At the same time, a passa~e is prsvided
for exhaust gases to be released from the air chamber
of the remaining diaphragm. Upon interaction with the
shaft yoke and the spring mounted actuating means,
the relationship of the valve openings to the
pressurized gas acting on the surface of the respective
diaphragm is changed at the completion of the pumping
stroke so as to reverse the action of the pump. The
snap-action mechanism provided precludes the sticking
of the pneumatic reversing system in an intermediate
position.
ln operation, pressurized gas is introduced throu~h
a passageway into a valve member and is directed via
a passageway within the inner wall of the pump housing
to the air chamber o- one of the diaphragms within
the pump. As the piston action of the diaphragm
forces syrup from the diaphragm chamber out the appro-
priate passage to the dispensing outlet, movement of
the shaft also moves the remaining diaphragm in a
non-pressulizing direction. This same shaft movement
also engages the shaft yoke. As the shaft yoke moves,
it initiates the pivotal actlon of a pair of snap-
acting compression springs which, prior ~o rotating
-6- ~ 2
off-center, are pushing against each other. As the springs
rotate off-center, they uncoil and push the shaft and yoke along
in the direction of the established movement. The action of the
spring mechanism ensures that the movement of the diaphragm,
initiated by the air pressure, is ta~en to completion by the
snap action of the compression springs, while at the same time
reversing the flow of pressurized air within the valve member.
This procedure is then repeated as long as the dispensing outlet
is open and the s~rup is being dispensed as a pressurized stream.
When the dispensing outlet is closed, sufficient back pressure is
e~e~ted on the diaphragms to prevent shaft movement.
Thus the present invention provides an article for use with
a double-acting reciprocating pump comprising: (1) a module
housing; (2) said module housing including guide means therein;
(3) a valve actuating member mounted for reciprocating movement
within said guide means back and forth between ~wo end positions,
said valve actuating member having a first actuating means
extending transversely from said member on one side o~ said
member, said valve actuating member also having a second actuating
means extending transversely from said member on the opposite
side of said member; (4) snap-acting means operatively connected
to the second actuating means of said valve actuating member for
rapidly completing the movement of said mernber from one of its
two end positions to the other after said member has already
been moved part way to said other end position; and (5) control
valve means for providing driving fluid to said double-acting
reciprocating pump including a reciprocable valve element movable
between two alternate positions to alternately direct driving
fluid to driving sections of said double acting reciprocating
pump, causing said pump to reciprocate, said valve element having
means for operative engagement by said first actuating means on
said valve actuating mer~er.
-6a-
It has been determined in the course of the presen'c
invention that a reciprocating diaphragm pump for syrup in
a Post-mix beverage dispensing system can be provided such
that the liquid can be delivered under controlled pressure
conditions in a reliable manner. A reversing valve is
; provided which includes a pair of compression springs
bearing one on the other so as not to apply pressure of
the bearing surfaces on the pump shaft.
2,.
~7--
In an alternative embodiment of the present
invention, the control or reversing valve, the recip-
rocating actuating member and the opposed coil
springs are provided in a common housing or rnodule.
This module is removably secured to the pump body
adjacent to the pump shaft and can be removed as
a unit for ease of repair. The module housing is
preferably molded from plastic in two pieces which
slide together with suitable tongue and groove
elementsO A top one o said pieces houses ~he
control or reversing valve, and has a slot on the
underside thereof for receiving the yoke or actuating
member of the reversing mechanism. The sides of the
slot form bearing surfaces parallel to the longitudinal
axis of the pump shaft. In ~his embodiment, the
yoke slides or rec;procates on these bearing surfaces
defined by the slot rather than on the pump shaft.
A bottom one of said two pieces comprises a support
for the opposed snap-acting spring mechanism of the
present invention which is sandwiched between said
top and bottom pieces. The yoke or actuating me~ber
has a pair of upwardly extending spaced arms for
engaging opposite ends of the control valve element
when it reciprocates, and a pair of downwardly
extending spaced arms for engaging a transverse pin
in the pump shat as the shaft reciprocates. A
central pin in the yoke couples it to the snap-
acting spring mechanisrn. This embodiment oE the
present invention also provides an improved spring
moun~ing means for the opposed compression springs and
a unique bearing structure therefor.
The present invention Fur~her provides a
keying or coding technique to assure proper assembly of
the iillet and outlet check valves o the pump. These
valves are disposed in cylindrical cartridges with coded pro-
trusions on the surface thereof to be received by cornplementary
coded slots in the respective inle~ and outlet ports. These
protrusions and slots are so arranged that it is impossible to
insert a cartridge into the ports backwards with respect to the
proper direction of operation. Thus, replacement o~ the valve
cartridges can be properly performed by an unskilled operator
and one valve cartridge can be used as either an inlet or outlet
valve~
In another embodiment the present invention provides a
houslng for a fluid operated double actin~ diaphragm pump com-
prlslng:
(a) a one-piece molded plastic pump body including
(1) a pair of spaced-apart end sections each of
which includes a central circular recess, for use as a
dxiving fluid chamber, a connecting 1ange surrounding
said end section and extending radially outwardly from
said recess, and a central shaft opening concentric ~o
said circular recess, said end sections being located
in-line on an axis passing through said shaft upenings
and being arranged in a plane perpendicular to said
axis and each of said end sections facing outwardly
away from the other end section such that said
recesses open outwardly away from said pump bodv,
25~ ~2) a ~luid inlet manifold enclosing a fluid
inlet passageway and extending be~ween and
connecting together said end sections, said inlet
manifold being parallel to said axis and being located
radially outwardly beyon~ said recesses, and terminating
at each end thereof in a fluid inlet port in each of
said connecting flanges and located radially outwardly
from said recesses, and said fluid inlet manifold
including a single fluid inlet located in-between
said ends thereof,
(3~ a fluid outlet manifold enclosing a fluid
outlet passageway and extænding between and connecting
together said end sections, said outlet manifold being
parallel to said axis and heing located radially
-8a~
outwardly beyond sald recC~ses, ancl terminating at each
end thereof in a fluid outlet por-t in each of sald con-
necting flanges and located radially outwardly from sald
recesses, and said flu1d outlet manifold including a
single fluid outle-t located in-between said ends thereof,
and
(4) a driving fluid manifold enclosing a driving
fluid passageway and extending between and connecting
together said end sections, said driving fluid manifold
being parallel to said axis and being located radi.al.Ly
inwardly of the peripheral edge of said recesses and
belng located radially outwardly from sa1d axis passing
through said central shaft opening and terminating at
each end thereof in a single driving fluid port in a
respective one of said end sections and in fluid com-
munication with the recess therein,
(b) a pair of identical, one-piece, molded plastic end
caps connected one each to a respective one of said end
sections, each of said end caps including
(1) a cen-tral section including a circular recess
concen-tric to sa1d pump body recesses, for use as a
discharge chamber,
(2) a connecting flange surrounding said central
section and extending radially outwardly from said
end cap recess and matingly engaging the adjacen-t end
section connecting flange, said end cap recess facing axially
inwardly toward the adjacent end section recess,
(3) a fluld inlet port located in said end cap
connecting flange and located radially outwardly from
said end cap recess and mating with said fluid inle~
port in the adjacent pump body connecting flange,
and a fluid inlet passageway extending between said
end cap fluid inlet port and said end cap recess to
provide fluid communication therebetween, and
(~) a fluid outlet port located in said end cap
connecting flange and located radially outwardly from
said end cap recess and mating with said fluid outlet
port in -the adjacent pump body connecting flange, and
-8b~
a fluid outlet passageway extending between said end
cap fluid outlet port and said end cap recess to provide
fluid communicatiQn therebetween, and
(c) means for connecting each of said pump body flanyes
to a respective one of said end cap flanges~
In another embodiment the present invention provides a
housing for a fluid operated double-actiny diaphragm pump com-
prising:
(a) a one-pi.ece molded plastic pump body including
a pair of substantially identical, spaced-apart in-llne,
end sections, each having an axially outwardly facing circular
recess for forming a drivirlg fluid chamber, surrounded
by a radially outwardly extending connecting flange, each
o~ said recesses being concentr:ic to the same axis and each
of said ~nd sections being oriented in a plane perpendicular
to said axis, manifold means t including an inlet manifold,
an outlet manifold and a driving fluid manifold, cxtending
betwe-~n and connecting sald end sections together and terminatlng
in fluid ports including an inlet port and an outlet port in
each of said connecting flanges and a driving fluid port in
direct fluid communication with said dri~ing fluid recess;
(b) a pair of id~ntical, one-piece, molded plastic
end caps connected one each to a respective one of said end
sections, each of said end caps having an axially inwardly
facing circular recess and each having a radially outwardly
extending connecting flange that mates with a respective
one of said end section connecting rlanges for use in
assembling said end caps to said pump body, each ~f said
end caps also having an inlet port and an outlet port in
each of said flanges located so as to mate with the
respective inlet and outlet ports~ resp~ctively, in the
respective end section when said end c,lps are con.nected to
said pump body, and a fluid passageway extending between
each of said end cap i.llet and outlet ports and said end
cap recess,
(c~ a single, elongated check valve cartridg2~
including a check valve and a cax~ridge body~ located one
in each of said two fluid lnlet ports and one .in each of
said outlet ports, and mear~s for sealing one end of each of
said check valve cartridges to the respective port in the
pump body and the other end to a respective port in the end
cap, and
-8c-
(d) means for connecting each of said pump body connecting
flanges to the connecting flanye o~ a respective one of said
end capsO
BP~lEF DESCRIPTXON OF T}lE DRAWINGS
The present inven~ion will become more fully
understood from the detailed description given
hereinbelow and the accompanyin~ drawings which are
given by way of illustration only and thus are not
limitative of the present invention.
Figure 1 is a cross-sectional view of a first
embodiment of the pump of the present invention
representing the initial position of a pressure stroke
in the direction indiea~ed;
Figure lA is a top view of the pump of Figure 1,
illustratin~ the details of the fluid input and
output manifolds and the inlet and out~et valves of
the pump of the present invention;
Figures 2A ~nd 2B are part;al side and bot~om
v;ews respec~ively of the pump of Figure 1, illustra~ing
a first embodiment o the spring reversing sys~em of
the present invention as they snap over center toward
the right;
Figure 2C illustrates an alternate embodiment of
compressio~ springs to those illustrated in Figure 2B.
--9--
Figures 3A and 3B are pa~tial side and bottorn
views, respectively9 of the purnp of Figure 1,
illustrating the spring reversing ~echanism of
the present invention immediately after the snap-
over position of ~igures 2A, 2B, which causes the pump
shaft to reverse directions and Move to the left;
Figure 4 is a cross-sec~ional view of the
reversing valve of the present ivention in the
position that it occupies when ~he pump shaft of
Figure 1 is driven to the right;
Figure 5 is a cross-sectional view of the
reversing valve of the present invention in the
position that it occupies when the pump shaft of
Figure 1 is driven to the left;
Figure 6 is an exploded view illustrating the
details of how the yoke of the present invention
is mounted on the pump shaft;
Figure 7 is a partial view illustrating another
embodiment of the pump diaphragm of the present
invention;
Figure 8 is an exploded view of a second
embodiment of the pump o~ the present invention
and reversin~ mechanisnl t.herefor;
F;gure 9 is a cross-sectional view Or a fully
assembled pump of the embodiment of Figure 8;
Figure 10 is an exploded view of the control
valve and reversing mechanism ~odule of the present
invention attached to the pump of Figure 8;
Figure llA is a side view of a check valve
cartridge of the present invention illustrating
coded protrusions thereon;
-- l o--
Fi~ure llB is a diagrammatic view of only the
protrusion configuration adjacent the right en~ of
the cartridge of Figure llA;
Figure llC is a diagra~matic view of only
the protrusion configuration adjacent the le~t-hancl
end of the cartrid~e of Figure llA; and
Figure 12 is an end view of an end section of
the pump of Figures 8 and 9 including inlet and
outlet ports with coded groove configurations therein
or selectiYely receiving either the front or back
ends of the valve cartridge of Figure llA.
DETAILED DESCRIPTION OF THE DRAWINGS
Referring now to Figures 1 and lA there is seen
a cross-sectional side and top view respectively of a
first embodiment of the reciprocating pump of the
present invention generally designated 10 comprising
a housing 11 having an input manifold 12A and an
output manifold 12B in its top wall for carrying the
syrup to be pulnped from the inlet SI through the
respective chambers discussed below to the pump
outlet SO. Within an inner chamber 13 of the pump is
positioned a shaft 14 interconnecting diaphragMs 16A
and 16B. An actuating member or yo~e 17 with
protrusions or arms 17A is slida~ly supported on the
shaft 14 by the longitudinal bore 17B, Figure 67 passing
therethrough. A reversing valve 40 is attached to
the inner wall 21 of housing 11 w;thin the inner
chamber 13 of the pump. The shaft 14 is press-fit
with a pin 25 which UpOR operation of the pump7
travel~ with the movement o~ ~he shaft a predetermined
distance ~efore enga~ing an end of slot ~6 provided
in the yoke 17. Shaft 14 is mounted for sliding
f~ 2
movement in O-ring seals OR at its respecLive ends.
Pivotally mounted beneath the yoke and interconnected
therewith i5 a spring actuating member 27 (Figures
2A, 2b, 3A, 3B) within the housing charnber 13. The
reversing effect of the valvP 40 is facilitated as
a resu]t of the interrelationship between the
actuating yoke member 17 and the spring actuating
means 27 and alternately directs pressurized gas
introduced through passageway 22 to the respective
air chambers 15A and 15B9 through passageways 23
and 24, to apply pressure to the respective
diaphragms 16A and 16B. The reversing valve 40
comprises a valve body 41 and spool element 42 with
O-rings 43. A more complete discussion of the operation
cf the reversing valve can be found below with
respect to Figures 2A, 2B, 3A, 3B, 4 and 5. Each
diaphragm of the pump is constructed of a flexible
material, such as rubber, secured to the inner
walls of the pump housing at positions 20.
In a preferred embodiment of the present invention,
the diaphragms further include a rnetal or plastic
piston on the outer face of the respective diaphragm
and a metal retaining cap on the inner surface of
the respective diaphragm, as illus~rated in Fi~ure
7 to be discussed hereinafter.
The pumping cycle of the pump of the present
invention and the flow of fluid therethrough can be
best illustrated by reference to Figure lA~ Fluid
to be purnped is introduced through an inlet SI to
input manifold 12A which extends across the top of
the pump and communicates with fluid chambers 28 and
29 via normally closed check valv2s 31L, 31R. When
the fluid pressure in input rnanifold 12A exceeds
the pressure in either chamber 28 or 29, check
valves 31L, 31R open. Since the pump of the present
invention is a reciprocating pump, the fluid
pressures in chambers 28, 29 are always in the
opposite state. That is, iE the pump shaft ir,
Figure lA is moving to the right,chamber 28 has a
higher fluid pressure than manifold 12A, and chamber
29 has a lower fluid pressure than manifold 12A.
Under these conditions, check valve 31L opens,
introducing fluid into chamber 29 and check valve
31R is closed. Thus, as the pump cycles, check
valves 31L, 31R alternately open and close.
Outlet check valves 32L, 32R, disposed in an
outpue maniEold 12B, function in subst~ntially the
same manner. That is, when the pressure output
manif~ld 12B is less than the pressure in one of the
respective chambers 28, 29, the check valve in that
chamber opens, discharging fluid therefrom to pump
outlet SO. In the above example, with the pump
shaft 14 movin~ to the right, the pressure in
chamber 28 is high, thus opening valve 32R and
permitting the fluid therein to discharge via manifold
12B and pump outlet SO.
The check valves 31L, 31R9 32L, 32R are substan-
tially identical except for the respective orientations
thereof. Each is formed from rubber and includes a
central stern fixedly mounted in the purnp wall, and
a disc-shaped seat B, which normally seats on fluid
ports C. When biased by fluid pressure ~o open~
disc-shaped seat B flexes as~ay from ports C~ permitting
fluid to pass therethrough.
-13-
The above-described outlet check valves are
disposed at the highest positions of chambers 28,
29 to preclude the formation of air pockets which
could be sucked OUL through pump outlet SO, resulting
in an uneven flow of fluid.
Figure 6 illustrates the details of actuating
me~ber or yoke 17, which is mounted for movement on
shaft 140 Yoke 17 includes a pair of upstanding
arms 17A described hereinbefore for engaging the
valve 40 and switching the same from one state to
another. A longitudinal bore 17B is provided in
yoke 17 for receiving pump shaft 14. After pump
shaft 14 is inserted in bore 17B, pin 25, described
hereinbefore is press-fit into aperture 14A in
Shaft 14. A bcttom plate 17C is suitably attached
to the bottom of yoke 179 thus supporting a pair of
pins 39 therein. As will be discussed hereinafter,
pins ~9 support one pair of ends of spring members
of the snap acting mechanism illustrated in Figures
2B and 3B.
Re~erring now to Figure 2A, 2B, there is seen
in cross-section the pump mechanism set forth in
Figure 1 representing a pressure stroke of the pump
in the direetion indicated at tlle point o~ engagement
of the pin 25 of shaft 14 with an end of slot 26 in
the shaft yoke 17. At this instant, the yoke is
picked up by pin 25 and begins to move with the shaft
and the spring actuating member 27, connected to ~he
yoke, begins to pass over center. The diaphragm 16
applies pressure to the liquid present in the chamber
289 which is released ~ia check valve 32R ;nto pas-
sageway 12B and direc~ed out through the pump ou~let SO
to the respective discharge stations. Figures 2B, 3B
represent the position of the diaphragm9 sha~t and
yoke at the completion of the stroke, As the reversing
mechanism, generally indicated 27, moves over center, I
there is produced a snap action effect which thrusts
one arm 17A o~ the yoke against the protruding end
of the spool 42, thus changing immediately the
position of the O-rings of the valve so as to suddenly
reverse the flow of pressurized air through the
valve 40 at the comple~ion of the stroke,and reverse
the piston action of the pump.
Figures 2B and 3B illustrate the details of the
spring reversing mechansim 27. The spring reversing
mechanism in one embodimen~ comprises a coil spring
36 wrapped about a pin 37 and pivotally attached by
way of pin 38 to the housing and pin 39 to the yoke
17. Upon engagement by the pump shaft, the yo~e 17
will move in the direction of the stroke of ~he
pump, which in turn rotates pins 37 over center
about pins 38 such that the springs 36 take over
and push the yoke in the direction of the established
movement at a speed faster than the shaft movement,
until the yoke hits agains~ the spool 42 of the
valve mechanism so as to reverse the direction of
the flow of pressurized air within the system and
establish the piston action of the pump in the
opposite direction. The position of the compression
springs and yoke at the ends of the stroke are
represented in Figure 3B. The presence of the pins
37 within the coil spring 36 prevents the spring
member from buckling during the movement of the
piston during the operation of ~he pump. Al~ernately,
torsion spring~ 36T may be substituted for the coil
springs 36 of Fig. 2B a~ illustrated in Fig. 2C to provide
the snap-acting actuating means of the present
invention. The yoke 17 slides or is pushed along
by the shaft and spring mechanism 27 oE the pump~
first in one direction then in a reverse direction
according to the reversing action of the valve 40.
In Figures 4 and 5, there is illustrated a
simplified enlarged cross-sectional view of the
reversing valve 40 of the present invention which
is represented herein as a spool valve comprising a
valve body 41, the spool 42 having three O-rings 43
intermittently positioned thereon within the valve
cavity 44. Within the upper area of the valve body
are located air passages 45 coupled to passage 22
of ~igure 1, for -introducing the pressurized gas into
the valve cavity 44, and 46 and 47 are coupled to
passages 23, 24 of Figure 1, for directing air through
the valve to the surface of the respective diaphragms
of the pump. The valve 40 herein represented shows
air under pressure being introduced ~o the valve
cavity 44 through passa~eway 45 such tha~ during the
first half of the reciprocating cycle, ~he air is
directed to the respective air chamber 15B, through
passageway 46 and passage~ay 24 (see Figure l~,while
at the same time remaining passageway 47 provides for
exhaust gases to be released as illustrated from
the air chamber of the remaining or opposite diaphragm
air chamber lSA. Upon contact by the left protruding
end of the spool 42 w;th the yoke 17 as discussed
above, the spool 42 is thrust ~o the right such
that at the end of the pumping action the O-rings
43 shift their position as illustrated in Figure 5~
and the pressurized gas is now directed in the opposiee
direction so as to be introduced into the air
chamber 15A of the diaphragm 16A, thus driving the
pump in ~he opposite direction. In this position,
the right end of the spool now projects from the
valve cavity 44 and awaits to be engaged by an arm
17A of the shaft yoke in the reverse action of the
piston.
In operation9 the valve 40 al~ernates the air
flow through the respective passages 23, 24 to the
air chambers 15A, 15B of the diaphragms 16A, 16B.
The compression springs 36 or 36T interconnected to
the yoke continuously urge the shaft of the
diaphragm pump first in one direction then the
other, responsive to the location of the yoke 17
along the shaft. The pressurized air is introduced
intc the air chambers 15A, 15B behind the respective
diaphragms 16A, 16B and drives the diaphragms so as
to discharge the liquid from the diaphragm chambers.
As staLed above, the yoke 17 on the shaft 14
initially moves in conjunction with the movement of
the shaft upon engagement of an end of slot 26 with
the pin 25 in shaft 14. The co~pression springs 36
or 36T, which at the time of engagement are pushing
against each other, with substan~ially no net force
in a direction transverse to the pump shaft, pivot
over center and apply a further driving force to
the yoke which is then caused to move quickly by
the snap-action of the springs 36 to seat the
projecting portions or arms 17A of the yoke 17
against the protruding spool 42 of the valve 41.
This changes ~he positions of the O rings within
the valve body and reverses the flow of pressurized
air therein thus completing the first half of the
cycle of the diaphragm pump. The continuous
~æ
introduction of pressurized air into the valve 40
ini~iates the pumping action of the shaft mounted
piston in the opposite direction, first compressing
the springs 36 or 36T and then repeating the action
described above in the opposite direction, the
compressed springs now pushing in the opposite
direction. The spring reversing mecharlism ensures
that the movement of either of the diaphragms
initiated by the air pressure, is completed, thus
preventing premature reversal of the pumping stroke
or sticking of the valve 40 in a central position.
Referring now to Figure 7, there is seen in
crosssection a pu~p construction similar to that
discussed above with respect to Figures 1 and lA7
except with respect to the structure of diaphragms
16A, 16B. The diaphra~ls 16A and 16B further include
cup-shaped plastic or metal plates 52 on the outer
face of the respective diaphragm surface and cup-
shaped retaining cap 54 on the inner surface of the
respective diaphragms. This configuration eliminates
the formation of crevices in the flexible diaphragm.
Preferably, the pump housing is construcLed of
a molded plastic, as herein represented in Figure 1,
such that the valves are mounted through the pump and
all the lines or passageways run inside the plastic
housing. This construction eliminates unnecessary joints
and external lines which contribuLes to a more reliable
system. As is seen in Figure 1, the inner wall of the
housing comprises one continuous member which surrounds
the pump reversing system components. The outer ~alls
of the housing 11 are also fabricated of molded plastic
which provides for an overall more desirable construction
of the diaphragm pump vf the present invention.
~$~
Referring in detail to Figures 8 and 9, there
is illustrated an additional embodiment of a pump
construc~ion in accordance with the present
invention. Figure 8 is an exploded view to illustrate
how the pump is assembled, and Figure 9 is a cross-
sectional view illustrating the pump in a fully
assembled condition. The main pump body includes
end sections 102 having fluid discharge chambers
105 formed therein and inlet and outlet ports 142,
144, respectively. In addition, each end section
102 has an annular groove or recess for receiving
the flexible diaphragms 118 therein about the periphery
thereof. The diaphragms 118 may include metal or plastic
piston members 119 nested therein. The end sections
102 of the main pump body also include central
apertures 107 for slidably receiving the pump shaft
104 extending between and into the respective
discharge chambers 105. The shaft 104 is mounted
within apertures lû7 by suitable 0-rings 110,
bushings 112 and retainer 114. The ends of the pump
shaft 104 are coupled to the diaphragm assembly and, more
specifically, pistons 119 by retainers (not shown in Fig. 8
but generally illustrated in ~ig. 9) and a suitable washer 116.
The two end seceions 102 of ~he main pump body
are molded as one piece with inlet and outlet manifold
tubes 143 and 141, respectively, which connect the
two end sec~ions 102 and the respective inlet and
outlet ports 142~ 4, therein. Fluid inlet 139 is
provided in manifold tube 143 and fluid outlet 140
is provided in manifold tube 141. Suitable connectors
for flexible rubber hoses such as 132 may be secured
to the respective inlet and outle~s 139 and 140 by
suitable O-tings 134, screws 136 and retainer
hooks 138.
_19_
A plurality of check valves to be described
further hereinafter with reference to Figures 11 to
12 are provided for in.sertion into the inlet and
outlet ports 142, 144 in the end sections 102.
These check valve cartridges include a main
cylindrical body 122 with 0-rings 124 at the ends
thereof and a flexible flapper type of check valve
125 including a flexible disc on a central stem.
The external surface of the cylindrical cartridges
is provided with coded protrusions or bumps to be
described further hereinafter with reference to
Figures 11 to 12. As will become more fully
apparent hereinafter, these coded protrusions 123
fit into coded slots 146 in the respective inlet
and outlet chambers 142, 144, the respective config-
urations of the protrusions and slots being such as
to preclude the insertion of the check valve
cartridges into the inlet and outlet ports in the
wrong direction.
Once all of the respective components such as
diaphragms 118, check valve cartridges 122, pump
shaft 104 and so forth are inserted into the end
section 102 of the main pump body, the end caps 100
may be secured to the end sections 102 by suitable
screws 126 which extend throu~h apertures in a
peripheral flan~e of ~he caps 100 into threaded
apertures in the periphery of a flange extending
around end sections 102. Thus, the end sections
102 of the main pump body and the end caps 100
screwed thereto define the respective discharge
chambers of the pum~ of this embodiment of the
present invention.
It should be noted at this juncture that the
check valve cartridges 122 of the present invention
become sandwiched between the end sections 102 of
-2(~- `
the pump body and the end caps 100 and both end
sections 102 and end caps 100 are provided with
coded slot configurations 146 for receiving the
coded protrusions on the surface of the check valve
artridge. The end caps 100 are further provided
with molded pins extendin~ from the ends thereof
disposed in a symmetrical pattern. These pins may
be utilized for supporting the pump in a mounting
bracket (not shown).
A control valve and reversing mechanism module
200 to be further described in connection with
Figure 10 is secured to an appropriate portion of
the manifold section of the pump by screws 130
adjaeent to and just above the shaf~ 104 on a
bracket 201A which is integrally formed with a driv:ing
gas manifold. The gas manifold communicates with both
discharge chambers and ~he outputs of the control valve
within module 200. A like bracket 201B is provided at
the bottom of the pump housing as illustrated in Figure
8 and faces the opposite direction from bracket 201A.
As illustrated in Figure 9, the control
valve and reversing mechanism module 200 is disposed
in operative engagement with a washer 106 fixedly
secured to pump shaft 104 by retainer rings 108.
As will become more fully apparent hereinafter with
respect to Figure 10, the washer 106 performs a
similar function to the pin 25 disposed in the pump
shaft of the embodirnent of Figure 1.
Referring in detail to Fig~re 10, there is
illustrated an exploded view of a comLined control
valve and reversing mechanism module oE the present
inventiorl for use wi th t:he pump of Figures 8 and 9.
The module housing is generally indicated 200 and
in~ludes a top housing portion 202 and a bottom
housing par~ion 2049 the bottom housing por~ion 204
being slidably received within the top housing
portion 202 in an assembled condition by means o
slots 214 which receive tongue port;ons 215
-21-
extending upwardly from the bottom housing portion
204. On the underside oE housing portion 202,
~here is provided a slot 210 which extends
transversely across the entire top portion 202 and
the side walls 212 thereof define bearing surfaces
on which the edges of a yoke or actuating member to
be described hereinafter may slide parallel to the
pump shaft 104. The top of housing portion 202 is
molded with chambers therein for receiving the
control valve of the present invention which is
similar in operation and construction to the control
valves 40 illustrated in Figures 4 and 5 described
hereinbefore. That is, the cylindrical chamber 206
is molded in housing portion 2û2 for receiving a
plurality of interconnected bushing elements and
dividing O-rings 230 which define the different
sections of the control valve body bore. The bushings
include a central inlet bushing 228 which would be
juxtaposed within inlet ports such as 45 of the
valve of Figures 4 and 5 and outlet bushings 226
which would be juxtaposed with the outlet paths 46
and 47 of the valve of Figures 4 and 5. These
bushings would include peripheral apertures in
align~ent with respective channels 45, 46 and 47 to
permit the flow of fluid therethrough. Disposed
for reciprocal sliding movement within the bushings
226 and 228 is a spool member 220 with spaced O-
rings 222 thereon of a similar construction to the
spool 42 illustrated in the valve of Figurc 4 and
5. This spool 220 is retained within the cylindrical
chamber 206 and the respective bushings described
hereinbefore by a screw-type retainer 224 s~hich is
scre~ed into one end of the chamber 206 in housing
portion 202. Both retainer 224 and the opposlte
f~
end of cy]indrical chamber 206 are provided with
keyholetype ports 218 having enlarged wing portions
219 which permit the escape of exhaust gas during
the reciprocal action of the valve. The wing
portions 219 provide for better exhaust venting of
the gas from the valve and assist in a self-clearling
action of the spool 220. The top housing portion
202 is further provided with an upstanding flange,
including apertures 216 therein for receiving
screws 130 which attach the entire module 200
to the pump assembly in communication with a suitable
manifold structure 141 which supplies driving gas
to either one of the pump discharge chambers on the
inboard side of the diaphragms to thereby drive the
pump in a reeiprocating action, as described in
detail hereinbefore. The supply of driving gas to
the module 200 of Figure 10 is through inlet port
208 in the top housing portion 202. This inlet
port 20~ may be fitted with an adaptor 132, retainer
hook 138 and 0-ring 134 secured thereto by a screw
136 of a similar construction to the adaptors
described i~ connection with Figure 8 hereinbefore.
The provision of these adaptors enables the pump
and control valve unit of Figure 10 to be connected
to flexible hoses or tubes.
The module 200 has a reciprocating yoke or
actuating member therein between the top and bottom
sections 202 and 204. Yoke member 240 slides in
slot 210 in top section 202 on bearing surfaces
provided by walls 212 thereof Yoke or actuating
member 240 is stamped from sheet Metal and is configured
with upstalldlrlg arms 242 at the opposite end thereo
with anv;1 portions ?41 stamped therein ~or engaging
the opposite ends of spocl valve elemen~ 220 as it
-23-
reciprocates with the action of the pump shaft. In
this regard, a pair of spaced arms 246 extend
downwardly from the yoke 240 for engaging the
washer 106 on the pump shaft 104, as illustrated in
Figure 9. Yoke240 is also provided with a
downwrdly extending pin 244 which firts into
apertures 258 in the end of pins 254 of a snap-
acting spring mechanism to bve described hereinafter.
The bottom housing portion 204 is provided with
slots 264 to permit the reciprocal movement of arms
246.
The opposed compression spring snap-acting
reversing mechanism utilized in the module 200 of
Figure 10 includes a pair of tubular spring support
sockets 248 having bores 250 therein for receiving
bothe coil compression springs 252 and support pins
254 therefor. The springs 252 may be inserted
within bores 250 and the pins 254 then inserted
within the springs to provide a quick and easy
assembly method of this snap-acting mechanism.
Extending from the top and bottom of members 248
are pivot pins 249 awhich are received in aligned
apertures 262 in the bottom portion 204 and the top
portion 202. Thus, the socket members 248 are
sandwiched between the top and bottom housing
portions of the module 200 and are pivotally
mounted in the apertures 262 in the respective to[
and bottom portions of the houding, Thje apertures
262 in the top housing portion 202 are not illustrated,
but they are directly aligned within the slot 210
above apertures 262, illustrated in the bottom
housing portion 204. The support pins 254 of this
embodiment of the present invention alsdo have a
unique end bearing structure, including circular
-2~-
end members 256 and arcuate engaging bearing flanges
260. When assembled together, these two end bearing
structures, including circular members 256 and
arcuate bearing ~]anges 260, nest one within the
other, and the respective circular end members bear
a~ainst the opposed arcuate bearing flan~e members
260 of the opposing support spring mechanism. This
structure is particularly ~nique and significant
for increasing the life of this spring-acting mechanism
and also more compact in size. That is, because of
this increased bearing area and nesting arrangement,
the bearings have a long life. In addition, this
bearing arrangement is particularly efficient and
unlikely to bind or stick as the coil springs move
over center in the snap-acting fashion described
hereinbefore with respect to Figures 2 and 3.
All ~f the parts of the module 200 of Figure 10
are fabricated from plastic with the exception of
yoke member 240, springs 252, spool 220 and bushings
226, 228. Of course, it is also preferable that
the screws, such as 266 which hold the two housing
portions togethers be fabricated from metal. Of
course, all parts may be plastic if desired.
The operation of the control valve in reversing
mechanism module 200 o~ Figure 10 should be readily
apparent from the description of the alternate
embodiments of the present invention described in
conjunction with Fi&ures 1 to 7. That is, the
reciprocation of the spool 220 within the control
valve bore 206 causes driving gas to be a]ternately
provided to the discharge chambers of the pump on
the inboard side of ~he diaphragms, depending upon
the position of the spool. This movement of one or
the other of the diaphragms creates the pumping
.
action and simul~aneously reciprocates the pump
shaft, causing the shaft and the ring or bushing
150 thereon to engage one of the downwardly
extending arms 246 of the yoke member 240. This, in
turn, causes the yoke member 240 to reciprocate,
and the pin 244 extending downwardly there~rom to
apertures 258 in the ends of spring support pins
254 causes pins 254 to rotate about pins 249 of
recaining sockets 248. IJhen pins 254 and coil
springs 252 thereon move over center (past a line
perpendicular to the longi~udinal axis of yoke
240), esil springs 252 cause ~he springs to snap
and accelerate the yoke. The arm 242 on the trailing
end then bangs against the associated end of spool
220, causing the valve to switch to its opposite
bistable position. As in the spring configuration
of ~igures 2 and 3, the symmetrical opposed springs
in a common plane precludes the occurrence of
transverse forces on the bearing surfaces 212.
Thus, yoke 240 will not stick in an intermediate
position of the extreme positions of travel. The
bearing structure 256, 260 on the ends of pins 254
further decreases any possibility of sticking cr
binding of the reversing mechanism.
Referring in detail to Figures 11 and 12, there is
illustrated the novel coded valve cartridge of the
present invention in conjunction with the inlet and
outlet ports in which it is contained. Figure llA
shows a side elevational view of the valve cartridge
of the present invention, including at its ront
end or the right end, as viewed in Figure llA, a
pair of diametrically-opposed protrusions 123F, and
at the rear or left end, as viewed in Figure llA,
three spaced protrusions 123R. It should be
82
understood that the third protrusion 123R in Figure
llA is not illustrated in the side view. However7
the third protrusion is illustrated in Figure llC,
to be described hereinafter. In this regard,
Figures llB and llC are diagrammatic i~lustrations
of only the protrusion configurations of the
respective right and left sides of the cartridge
illustrated in Figure llA. That is, Figure llB
illustrates two diametrically-opposed protrusions
123F and Figure llC illus~rates three spaced
protrusions 123Ro
Figure 12 illustrates an end section 102 of the
pump of Figures 8 and 9 of the present invention
and inlet and outlet ports 142 and 144~ respectively.
Inlet port 142 includes three spaced grooves 146R
for receiving only the three-spaced protrusions
123R vf the configuration of Figure llC. Therefore,
only the rear or left end of the valve cartridge of
Figure llA can be inserted into inlet port 142~
This assures that the check valve within the valve
cartridge of Figure llA cannot be inserted backwards
within the inlet port 142~ In a like manner, the
diametrically-opposed pair of grooves 146F in outlet
port 144 will only receive the protrusion
configuration of Figure llB which has two
~ diametrically-opposed protrusions 123F. Thererore,
only the front or right end o~ the valve cartridge
of ~igure llA may be inserted nto the outlet port
144 in the end section 102 o the pump of the present
invention.
Thus, it can be clearly seen ~hat a single
valve cartridge having the protrusion coding config-
uration of Figure llA may be utilized for insertion
into any one of the four inlet and outlet ports
142, 144 o~ the pump of the present inven~ion; and
-27-
Z
it is impossible to insert the cartridges
improperly.
In the preferred embodiment of the present
invention, the end caps 100 of the pump of Figures
8 and 9 also have coded groove confi~urations for
receiving the end of the valve cartridge of Figure
llA, which is not contained within the inlet and
outlet ports 142, 144 of Figure 12. That is, if
the cartridge of Figure 11 is inserted in the inlet
port of Figure 142, the three spaced protrusions
123R are contained within that port while the
diametrically-opposed protrusions 123F at the opposite
end of the cartridge extend from the port 142.
Therefore, a chamber 147 in end cap 100 of the purnp
would have a diametrically-opposed pair of slots
therein Eor receiving the pair of diametrically-
opposed protrusions 123F. In a similar manner,
with the pair of diametrically-opposed protrusions
123F inserted in outlet port 144 and slot 146F, the
three spaced protrusions 123K of the cartridge
would ex~end out of outlet port 144. Thus, a
chamber 149 in end cap 100 of the pump in Figure 8
would require the presence of three spaced slots to
receive the protrusions 1~3R therein. In this
manner, a double coding of the parts is achieved,
so that it is impossible to insert the valve
cartridges backwards into the inlet and outlet
ports 142 and 144, and it is also impossible to
assemble the end caps 100 to the end section 102
without having the check valve cartridges properly
inserted within the inle~ and outlet ports 142,
144.
-2~-
The invention being thus described, it will be
obvious that the ~same rnay be varied in many way~.
Such variations are not to be regarded as a
departure from the spirit and scope of the present
invention, and a]l such modifications as wou]d be
obvious to one skilled in the art are intended to
be inc]uded within the scope of the following
claims.
