U.S. patent number 3,640,433 [Application Number 04/842,793] was granted by the patent office on 1972-02-08 for beverage dispenser for metering a plurality of liquids.
This patent grant is currently assigned to The Coca-Cola Company. Invention is credited to Joseph J. Rodth.
United States Patent |
3,640,433 |
Rodth |
February 8, 1972 |
BEVERAGE DISPENSER FOR METERING A PLURALITY OF LIQUIDS
Abstract
Apparatus including a plurality of coaxial pistons reciprocable
in unison in a chamber of a pump body for simultaneously admitting
different fluids to and discharging them from the chamber, the
pistons defining fluid-metering compartments and an operating
compartment in the chamber, means for supplying fluids to the
chamber including a tank for one of the fluids, and supply and
return means including a conduit in permanently open communication
with the operating compartment for alternatively supplying said one
fluid in raw condition thereto for operating the pistons and for
returning said one fluid when spent to the tank to be conditioned
for subsequent discharge.
Inventors: |
Rodth; Joseph J. (Swansea,
MA) |
Assignee: |
The Coca-Cola Company (Atlanta,
GA)
|
Family
ID: |
25288249 |
Appl.
No.: |
04/842,793 |
Filed: |
July 11, 1969 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
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681219 |
Nov 7, 1967 |
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Current U.S.
Class: |
222/129.2;
222/129.4; 222/137; 222/146.6 |
Current CPC
Class: |
B67D
1/107 (20130101) |
Current International
Class: |
B67D
1/10 (20060101); B67D 1/00 (20060101); B67d
005/56 () |
Field of
Search: |
;222/129.1,129.2,129.3,129.4,146C,148,137,133,146HE,146 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Reeves; Robert B.
Assistant Examiner: Scherbel; David A.
Parent Case Text
This application is a continuation-in-part of applicant's prior
copending application Ser. No. 681,219, filed Nov. 7, 1967, now
abandoned and assigned to the assignee of this invention.
Claims
I claim:
1. An apparatus for simultaneously dispensing different fluids in a
blended beverage of measured proportions and comprising a body
having a chamber, a pumping member reciprocable in the chamber
between loaded and discharged positions and dividing the chamber
into a plurality of fluid-measuring chamber portions and an
operating chamber portion, fluid circuit means in communication
with the measuring chamber portions for admitting different fluids
to and discharging them simultaneously from the measuring chamber
portions respectively, the fluid circuit means including a
pressurized source of supply for one of the fluids, means for
holding said one fluid for discharge, and a common inlet and outlet
passage connected to the operating chamber portion and serving to
communicate the operating chamber portion alternately to the source
of supply, for driving the pumping member to discharged position,
and to the holding means for conveying said one fluid thereto from
the operating chamber portion for subsequent discharge.
2. The apparatus of claim 1 wherein said chamber portions are in
coaxial alignment, and wherein the pumping members comprises a pair
of coaxially spaced pistons and a connecting rod joining the
pistons to form a one-piece operating unit.
3. The apparatus of claim 1 wherein the pressurized source of
supply includes a water tank, and wherein the apparatus further
includes a concentrate tank in separated relation to the water
tank, the fluid circuit means further including separate inlet
passages and outlet passages connected to each of the measuring
chamber portions for simultaneously admitting concentrate and water
thereto when the pumping member moves to loaded position and
simultaneously conducting discharged concentrate and water away
from the measuring chamber portions when the pumping member moves
to discharged position.
4. The apparatus of claim 3 further including a serving nozzle
having a mixing chamber and a discharge orifice downstream thereof,
the outlet passages of the measuring chamber portions respectively
opening into the mixing chamber for independent delivery of
accurately measured quantities of concentrate and water to be mixed
and discharged in a blended beverage of measured proportions.
5. The apparatus of claim 3 wherein the fluid circuit means further
includes valve means between the pressurized source of supply and
the operating chamber portion for controlling longitudinal movement
of the pumping member, and an additional valve means for closing
the inlet passages to each of the measuring chamber portions during
movement of the pumping member from loaded to discharged
position.
6. The apparatus of claim 1 wherein a metal extension sleeve of
high thermal conductivity is secured to the body between the
plurality of fluid measuring chamber portions so as to provide a
high rate of heat exchange between said chamber portions.
7. An apparatus for simultaneously dispensing different fluids in a
blended beverage of measured proportions and comprising a metering
pump including a body having a longitudinally extending chamber,
coaxially aligned pistons joined together for simultaneous
reciprocating movement in the chamber between loaded and discharged
positions and dividing the chamber into a plurality of fluid
measuring chamber portions and an operating chamber portion, a
plurality of isolated tanks respectively containing different
fluids, inlet and outlet means for each of said chamber portions
including separate inlet connections between the tanks and the
fluid measuring chamber portions, respectively, and supply and
return passage means connected with the operating chamber portion,
a fluid supply line for supplying one of the fluids in a raw state
under pressure, and a fluid valve in the supply and return passage
means for alternatively connecting the operating chamber portion to
the fluid supply line and one of the tanks to respectively drive
the pistons into discharged position and, upon their return to
loaded position, to exhaust spent raw fluid to said one tank for
discharge in a subsequent dispensing operation:
8. The apparatus of claim 7 wherein said tanks include a water tank
and a concentrate tank in isolated relation to the water tank,
wherein heating means is provided for the water tank and heat
absorbing means is provided for the concentrate tank, and wherein
heated water and refrigerated concentrate are independently
conducted to the measuring chamber portions of the pump,
respectively, through the separate inlet connections thereto
responsive to piston movement from discharged to loaded
position.
9. The apparatus of claim 8 wherein a part of the body surrounding
at least a portion of the water-measuring chamber portion of the
pump is received within the water tank in good heat-conducting
relation to its heated contents, the concentrate-measuring chamber
portion being positioned in its entirety outside the confines of
the water tank.
10. The apparatus of claim 8 wherein the fluid valve in the supply
and return passage means is normally closed to the fluid supply
line and normally open to the water tank, and wherein a second
fluid valve is provided in the inlet connection to the water
measuring chamber portion of the pump, the second fluid valve
normally being open to permit communication between the water tank
and the water-measuring chamber portion for charging the same with
a supply of heated water to be discharged, said fluid valves being
simultaneously operable to effect reversal of their operative
positions for supplying raw water to the operating chamber portion
while closing the water tank to both the operating and water
measuring chamber portions during piston movement from loaded to
discharge position.
11. The apparatus of claim 8 wherein the supply and return passage
means is connected for exhausting spent raw water into a bottom
portion of the water tank, and wherein the inlet connection for the
water measuring chamber portion of the pump is connected to open
into an upper portion of the water tank.
12. The apparatus of claim 7 further including a return spring
received in the chamber and seated against the body and one of the
pistons for continuously urging them toward loaded position.
13. An apparatus for simultaneously dispensing two different fluids
in a blended beverage of measured proportions and comprising a
metering pump including a body having a longitudinally extending
chamber, a pair of coaxially spaced pistons and a connecting rod
joining the pistons to form a one-piece operating unit
longitudinally reciprocable in the chamber in unison between a
loaded limit position and a discharged limit position, the pistons
dividing the chamber into coaxial chamber portions including a pair
of fluid-measuring chamber portions and an operating chamber
portion, a return compression spring in the chamber continuously
urging the pistons toward said loaded limit position, one of the
pistons being of U-shaped half-section opening toward the spring
and receiving the same in concentric relation thereto, fluid
circuit means in communication with the measuring chamber portions
for simultaneously admitting two different fluids to and
discharging them from the measuring chamber portions respectively,
the fluid circuit means including a fluid valve and a common supply
and return passage connecting the fluid valve with the operating
chamber portion for controlling longitudinal movement of the
pistons, the common supply and return passage being in permanently
open communication with the operating chamber portion and providing
a highly responsive pumping action with minimal time delay.
14. The apparatus of claim 13 wherein said one piston has an
annular end wall, and wherein a rolling diaphragm is secured to the
body and to one side of the end wall of said one piston opposite
the spring for supporting said one piston for frictionless,
self-centering movement relative to the longitudinal axis of the
chamber.
15. The apparatus of claim 14 wherein a ball bearing assembly is
mounted on an opposite side of the end wall of said one piston with
a thrust plate interposed between the spring and the ball bearing
assembly, whereby said one piston is free to rotate relative to the
spring for ensuring minimal twisting of the diaphragm.
16. An apparatus for simultaneously dispensing two different fluids
in a blended beverage of measured proportions and comprising a
metering pump including a body having a longitudinally extending
chamber, a pair of coaxially spaced pistons and a connecting rod
joining the pistons to form a one-piece operating unit
longitudinally reciprocable in the chamber in unison between loaded
and discharged positions, the pistons dividing the chamber into
coaxial chamber portions including a pair of fluid-measuring
chamber portions and an operating chamber portion, a guide tube
coaxially mounted in the chamber between the pistons, one of the
pistons being of U-shaped half-section having an elongated hub
portion slidably received in the guide tube for maintaining the
pistons in radially self-centering alignment in the chamber, and
fluid circuit means in communication with the measuring chamber
portions for simultaneously admitting two different fluids to and
discharging them from the measuring chamber portions respectively,
the fluid circuit means including a fluid valve and a common supply
and return passage connecting the fluid valve with the operating
chamber portion for controlling longitudinal movement of the
pistons, the common supply and return passage being in permanently
open communication with the operating chamber portion and providing
a highly responsive pumping action with minimal time delay.
17. An apparatus for simultaneously dispensing two different fluids
in a blended beverage of measured proportions and comprising a body
having a chamber, a pair of pumping members movable in unison in
the chamber between loaded and discharged positions and dividing
the chamber into a pair of fluid-measuring chamber portions and an
operating chamber portion, a water tank having heating means and a
concentrate tank having refrigerating means, the water tank and
concentrate tank each connected to one of the measuring chamber
portions, common supply and return passage means connected with the
operating chamber portion, a water supply line for supplying water
under pressure, and a fluid valve alternatively connecting the
common supply and return passage means to the water supply line and
the water tank for alternately supplying water under pressure to
the operating chamber portion to drive the pumping members into
discharged position and for returning spent water to the water tank
responsive to the pumping members moving into loaded position,
whereby the spent water is heated for subsequent discharge.
18. The apparatus of claim 17 wherein a part of the body
surrounding at least a portion of the water-measuring chamber
portion is received within the water tank in good heat-conducting
relation to its heated contents, the concentrate-measuring chamber
portion being positioned in its entirety outside the confines of
the water tank.
19. An apparatus for simultaneously dispensing different fluids in
a blended beverage of measured proportions and comprising a body
having a chamber, a pumping member movable in the chamber between
loaded and discharged positions, the pumping member dividing the
chamber into a plurality of fluid-measuring chamber portions and an
operating chamber portion, the measuring chamber portions each
having inlet and outlet means for simultaneously admitting
different fluids to the measuring chamber portions and discharging
the different fluids simultaneously from the measuring chamber
portions respectively, a conditioning tank for treating one of the
fluids and supplying the same for subsequent discharge, a
pressurized source of supply for said one fluid, a passage between
the operating chamber portion and the conditioning tank, and a
valve in said passage alternatively connecting the operating
chamber portion to the pressurized source of supply for said one
fluid and the conditioning tank to respectively drive the pumping
member into discharged position and, upon its return to loaded
position, to discharge said one fluid to the conditioning tank to
be treated for discharge in a subsequent dispensing operation.
20. An apparatus for dispensing a plurality of different fluids in
a beverage of measured proportions and comprising a body having a
chamber, pumping means movable in the chamber between loaded and
discharged positions and dividing the chamber into a plurality of
fluid compartments including an operating compartment, a tank, and
heating means for heating the fluid in the tank, the tank being
connected between the operating compartment and one of the other
fluid compartments for receiving fluid from the operating
compartment while additionally providing a source of heated fluid
for said one fluid compartment for subsequent discharge in a
beverage, the operating compartment having a maximum volume less
than that of said one fluid compartment to compensate for fluid
expansion upon heating the fluid received in the tank from the
operating compartment, thereby promoting a constant fluid level in
the tank.
21. The apparatus of claim 20 wherein a fluid displacement member
is fixed within the operating compartment for establishing the
volume differential between the operating compartment and said one
fluid compartment.
22. The apparatus of claim 20 further including a fluid supply
passage connected to the tank, and a fluid level control including
valve means in said passage and control means for opening and
closing the valve means responsive to the height of the fluid level
in the tank between predetermined minimum and maximum levels of
fluid in the tank.
23. The apparatus of claim 22 wherein the fluid level control
includes magnetically actuated switch means for controlling the
valve means, and a float controlled magnet for actuating the switch
means.
24. The apparatus of claim 20 wherein the chamber extends
longitudinally of the body and its fluid compartments are coaxially
aligned, the pumping means being reciprocable in unison within the
chamber between said loaded and discharged positions, and wherein a
fluid displacement member is coaxially fixed within the body for
providing the maximum volume differential between the operating
compartment and said one fluid compartment.
25. The apparatus of claim 24 wherein throw adjustment means is
releasably secured in a selected adjusted position on the fluid
displacement member to provide a stop for the pumping means upon
its return movements from discharged position to loaded
position.
26. The apparatus of claim 20 further including throw adjustment
means releasably fixed to the body in a selected adjusted position
and providing a stop limiting movement of the pumping means between
its loaded and discharged positions.
27. The apparatus of claim 26 wherein the stop provided by the
throw adjustment means is positioned within the chamber for
limiting return movements of the pumping means from its discharged
position to its loaded position, permitting uninterrupted travel of
the pumping means to a fully discharged position at an end of at
least one of the fluid compartments for ensuring self-purging of
said one fluid compartment irrespective of the adjusted position of
the throw adjustment means.
28. The apparatus of claim 1 further including throw adjustment
means providing a variable stop limiting movement of the pumping
member between its loaded and discharged positions and adjusting
the stroke of the pumping member therebetween for selectively
adjusting the maximum volume of fluid discharged from the fluid
compartments, the throw adjustment means permitting uninterrupted
travel of the pumping means to a fully discharged position at an
end of at least one of the fluid compartments for ensuring
self-purging of said one fluid compartment irrespective of the
adjusted stroke of the pumping means.
29. The apparatus of claim 28 wherein the throw adjustment means
provides a stop for return movements of the pumping means from its
discharged position to its loaded position.
30. An apparatus for simultaneously dispensing a plurality of
different fluids in a blended beverage of measured proportions and
comprising a body having a chamber, pumping means movable in the
chamber in unison between loaded and discharged positions and
dividing the chamber into a plurality of fluid compartments, fluid
circuit means in communication with the fluid compartments for
admitting fluids to and discharging them from the compartments, a
fluid tank, a passage connecting the tank to one of the fluid
compartments, and a valve in the passage for connecting the tank to
said one compartment, the valve establishing an open passage after
the pumping means is in discharged position but before return
movement of the pumping means to loaded position.
31. The apparatus of claim 30 wherein the valve is operable
independently of the pumping means.
32. The apparatus of claim 30 further including throw adjustment
means providing a variable stop limiting movement of the pumping
means between its loaded and discharged positions and adjusting the
travel of the pumping means therebetween for selectively adjusting
the maximum volume of fluid discharged from the fluid
compartments.
33. The apparatus of claim 30 wherein electrically actuated
solenoid means are provided for operating the valve.
34. The apparatus of claim 30 wherein the chamber extends
longitudinally of the body, wherein the pumping means is
reciprocable in the chamber and divides the chamber into three
different fluid-measuring compartments and an operating
compartment, the fluid-measuring compartments each having separate
fluid inlet and outlet means, and the operating compartment having
a common supply and return passage connected to the fluid tank.
35. The apparatus of claim 1 wherein the elongated pumping member
includes at least two piston portions joined by a rod of reduced
diameter reciprocable within the chamber and dividing it into
separate fluid-measuring chamber portions, wherein the fluids
dispensed from the fluid-measuring chamber portions are at
different temperatures, one of the fluid-measuring chamber portions
having a maximum volume establishing a preselected measured
quantity of fluid for discharge in a blended beverage, one of the
piston portions corresponding to said one fluid-measuring chamber
portion having a length greater than its stroke and minimizing
thermal conduction between adjacent fluid-measuring chamber
portions to promote discharge of the fluid from said one
fluid-measuring chamber portion at a preselected generally uniform
temperature.
36. The apparatus of claim 35 wherein the said one piston portion
has a low-friction fluid seal extending about its periphery, the
fluid seal being formed of a material of low thermal conductivity,
wherein the said one piston portion is dimensioned to provide a
preselected maximum clearance between the said one piston portion
and the chamber wall, and wherein fluid from one of the
fluid-measuring portion is received within said clearance to
provide a thin lubricating fluid film for the said one piston
portion.
37. The apparatus of claim 35 wherein a maximum clearance in the
order of 0.005-inch thickness exists between the said one piston
portion and the chamber wall.
38. A metering pump usable in a beverage dispenser for
simultaneously dispensing two different fluids in a two stroke
cycle and comprising a body having a longitudinally extending
chamber, a pair of coaxially aligned pistons reciprocable in the
chamber and connected in longitudinally spaced relation for
simultaneous movement between loaded and discharged positions, a
flexible rolling diaphragm secured to the body and supporting one
of the pistons for radially self-centering frictionless movement in
the chamber, the diaphragm and said one piston jointly forming a
movable partition within the chamber, the movable partition and the
other of the pistons dividing the chamber into a pair of
fluid-measuring chamber portions and an operating chamber portion,
a guide tube coaxially mounted in the chamber between the pistons,
said one piston being of U-shaped half-section having an elongated
hub portion slidably received in the guide tube, the measuring
chamber portions each having inlet and outlet means formed in the
body for simultaneously admitting two different fluids to and
exhausting them from the measuring chamber portions respectively,
and a return spring in the chamber continuously urging the pistons
toward loaded position, the return spring being coiled about the
guide tube and urging said one piston into loaded position, whereby
the guide tube assists in maintaining the pistons in radially
self-centering alignment in the chamber while additionally
supporting the spring to prevent excessive radial movement
thereof.
39. A metering pump usable in a beverage dispenser for
simultaneously dispensing two different fluids in a two-stroke
cycle and comprising a body having a longitudinally extending
chamber, a pair of pistons reciprocable in the chamber and
connected in longitudinally spaced relation for simultaneous
movement between loaded and discharged positions, a flexible
rolling diaphragm secured to the body and supporting one of the
pistons for radially self-centering frictionless movement in the
chamber, the diaphragm and said one piston jointly forming a
movable partition within the chamber, the movable partition and the
other of the pistons dividing the chamber into a pair of
fluid-measuring chamber portions and an operating chamber portion,
the measuring chamber portions each having inlet and outlet means
formed in the body for simultaneously admitting two different
fluids to and exhausting them from the measuring chamber portions
respectively, and a return spring in the chamber continuously
urging the pistons toward loaded position, said one piston being of
U-shaped half-section opening toward the spring and having an
annular end wall, the rolling diaphragm being secured to a side of
said end wall opposite the spring, and a ball bearing assembly
being mounted on an opposite side of said end wall with a thrust
plate interposed between the spring and the ball bearing assembly,
whereby said one piston is free to rotate relative to the spring
for ensuring minimal twisting of the rolling diaphragm.
Description
This invention generally relates to beverage dispensers and
particularly concerns a dispenser for discharging two or more
different liquids in a blended mixture of preselected
proportions.
A principal object of this invention is to provide an improved
beverage dispenser particularly suited for mixing precisely
measured proportions of two or more different fluids at the moment
of serving.
Another object of this invention is to provide an improved
dispenser of the above-described type capable of trouble-free
dependable operation in dispensing blended beverages in high speed
operating cycles.
Still another object of this invention is to provide such a
dispenser which discharges a mixture of liquids, one of which may
be heated almost to its boiling point, and which is particularly
suited to discharge such liquids in precisely metered amounts
without danger of vaporizing the heated liquid.
A further object of this invention is to provide an improved
beverage dispenser having minimal energy requirements and wherein
one of the fluids to be conditioned and dispensed is actually used
in a raw condition as an actuating fluid for effecting an operating
cycle and is then recycled to be conditioned and subsequently
dispensed in a beverage.
A still further object of this invention is to provide a metering
pump which not only meters and dispenses fluids in measured
proportions but also serves to assist in maintaining a desired
fluid level in a tank which receives spent actuating fluid to be
conditioned for subsequent discharge in a beverage.
Another object of this invention is to provide a dispenser capable
of simultaneously dispensing hot water and a cold concentrate and
wherein the arrangement of parts is particularly suited to
separately maintain each of the liquids at selected uniform
temperatures under widely varying conditions until they are mixed
and discharged.
A still further object of this invention is to provide an improved
metering pump of rugged compact construction having a minimum
number of moving parts and which exhibits significantly improved
operating characteristics in positively dispensing different
fluids.
Still another object of this invention is to provide a metering
pump of the above-described type which is quick and easy to
assemble and service.
Other objects will be in part obvious and in part pointed out more
in detail hereinafter.
A better understanding of the invention will be obtained from the
following detailed description and the accompanying drawings of
illustrative applications of the invention.
In the drawings:
FIG. 1 is a schematic view, partly in section and partly broken
away, showing one embodiment of a dispenser constructed in
accordance with this invention and wherein the dispenser is shown
in a loaded condition;
FIG. 2 is a view similar to FIG. 1 showing the dispenser in a
discharged condition;
FIG. 3 is an enlarged section view, partly broken away, showing
details of a metering pump embodied in this invention;
FIG. 4 is an enlarged section view, partly broken away, showing
details of a discharge nozzle embodied in this invention;
FIG. 5 is an enlarged view, partly in section and partly broken
away, showing another embodiment of a dispenser incorporating this
invention;
FIG. 6 is an enlarged section view showing a pump housing extension
arrangement;
FIG. 7 is an enlarged section view showing a piston seal
construction of the metering pump;
FIG. 8 is a reduced side view of a liquid level control
incorporated in this invention; and
FIG. 9 is a top view of the liquid level control of FIG. 8.
Referring to the drawings in detail wherein one embodiment of a
dispenser incorporating this invention is shown in FIGS. 1-4, it
will be understood that a housing, not shown, may be provided for
supporting and enclosing various operating components
(schematically illustrated in FIGS. 1 and 2) in operative assembled
relation. While the dispenser is capable of quickly and positively
discharging fluids of various types in different applications, it
is particularly suited for dispensing both hot and cold liquid
beverages. The term beverage will be understood to include a
variety of consumable liquids such as coffee, soup, beer, fruit
juices, vegetable juices, milk, tea and similar liquid foods and
drinks. Separate metered quantities of either hot or cold liquids
may be dispensed from each metering compartment of the dispenser,
but for purposes of illustration, the embodiment shown in FIGS. 1-4
will be described in connection with the metering and dispensing of
separate slugs of hot water and cold concentrate, or syrup, to
provide a blended hot beverage.
To effect precision metering and simultaneous discharge of water
and beverage concentrate in precisely proportioned quantities for a
single serving, a two-stroke cycle-metering pump 10 is provided in
accordance with this invention as best seen in FIG. 3. The pump 10
has a tubular body 12 and an attached coaxial housing portion 14
jointly defining a longitudinally extending chamber 16 wherein a
piston subassembly is received for reciprocating movement.
The piston subassembly includes a water piston 18 of U-shaped
half-section opening toward the housing portion 14 and a
concentrate piston 20 which is of reduced size and is reciprocable
within a cylindrical liner 22 preferably formed of stainless steel
for increased abrasion resistance while minimizing any resistance
to piston movement. The liner 22 projects beyond housing portion 14
and into a concentrate plug 24 suitably fixed to the housing
portion 14 by a nut 26 tightly drawn up against a snapring 28 fixed
around the concentrate plug 24.
Concentrate inlet and outlet fittings 30, 32 are provided in the
concentrate plug 24, and in the preferred embodiment, the inlet
fitting 30 is shown having a check valve 34 exclusively providing
one-way flow of concentrate into the plug 24 through a supply line
35 connected to an insulated concentrate tank 36 (FIGS. 1 and 2)
shown having a conventional heat-absorbing unit 37 for maintaining
the concentrate in a refrigerated condition until discharged in a
drink. Other arrangements, of course, could be provided, e.g.,
wherein a container is simply positioned within a refrigerated
compartment of the dispenser so that the container may be readily
removed and replaced for purposes of repair, cleaning or refilling
with any one of a number of different beverage concentrates. If
desired, the tank 36 could also be adapted to serve as a source of
concentrate to be dispensed at room temperature or even at elevated
temperatures depending on the uses to which the dispenser is to be
applied.
A throw adjustment screw 38 is threadably secured in a sleeve 40
pinned within an end of the plug 24. The screw 38 may be set to
project a preselected distance beyond an inner end of the sleeve 40
and then locked in position by a hex nut 42 to provide a left-hand
stop for the concentrate piston 20 defining a discharged position
for the piston subassembly.
The piston 20 is secured by a pin 44 to an axially extending
connecting rod 46 integrally fixed to a circular end plate 48 of a
cylindrical hub 50 of the water piston 18 which is reciprocable
within chamber 16 to an extent limited by the throw adjustment
screw 38 and a spacer plug 52 coaxially mounted inside the water
piston hub 50 to provide a right-hand stop defining a loaded
position for the piston subassembly. The spacer plug 52 is secured
to an end plate 54 fixed to body 12 by a retaining ring 56 secured
within an annular end cap 58 suitably retained on the right-hand
end of the body 12.
To provide a radially self-centering piston subassembly virtually
free of frictional resistance to piston movement, the water piston
18 in the preferred embodiment is supported by a rolling diaphragm
comprising an outer diaphragm sac 60 and an inner diaphragm sac 62,
each of which are clamped at one of their ends against end cap 58
and the spacer plug 52, respectively, by outer and inner peripheral
portions of a disk 64 fixed in position between end plate 54 and a
shoulder on the end cap 58. The diaphragm sacs 60, 62 have meeting
ends secured to an end wall portion of the water piston 18 by a
clamping flange 66 retained by a screw stud and locking hex nut
arrangement 68.
While the diaphragm sacs 60, 62 can be formed of any suitable
strong, tough flexible material, polymers and copolymers of
polypropylene are preferred and have been found to work
satisfactorily to effectively maintain the piston subassembly in
frictionless self-centering alignment relative to the longitudinal
axis of the chamber 16.
To assist self-centering reciprocating movement of the pump 10, a
perforated guide tube 70 is coaxially received within the chamber
16 and has a flared end 71 abutting housing portion 14 for seating
one end of a return compression spring 72 coiled about the guide
tube 70 and the water piston hub 50. It is to be noted that the
guide tube 70 additionally serves to maintain the return spring 72
in proper position. To continuously urge the water piston 18 toward
its loaded position (FIGS. 1 and 3), an opposite end of the return
spring 72 seats against an annular thrust plate 74 in abutment with
a ball bearing assembly 76. The latter is mounted on the end wall
portion of the diaphragm supported water piston 18, permitting it
to seek a properly oriented angular position independently of the
continuously applied biasing force of the return spring 72 to
minimize undesired twisting of the rolling diaphragm.
To maintain the ball bearing assembly 76 in assembled relation when
the pump 10 is stripped for servicing, the thrust plate 74 is
preferably maintained against excessive axial movement by a bearing
retaining ring 78 secured to a peripheral wall portion of the water
piston 18.
The piston 20 and the diaphragm-supported water piston 18 thus
divide chamber 16 into separate concentrate and water-measuring
chamber portions 80, 82 and a rear operating chamber portion 84,
the pistons 18, 20 and their respective chamber portions or
compartments being of predetermined sizes for precisely metering
measured quantities of concentrate and water in a fixed preselected
ratio which may be controlled in volume by setting the throw
adjustment screw 38. The forward concentrate compartment 80 is
provided with separate concentrate inlet and outlet fittings 30 and
32 as described above, and the intermediate water compartment 82 is
also provided with separate inlet and outlet fittings 86 and 88
secured to the body 12 and the housing portion 14 respectively.
While not described in detail, suitable fluidtight seals and
packing rings are provided as shown in the drawings to ensure
against undesired fluid leakage between component body parts as
well as between the different compartments of the chamber 16 and
their respective fittings in accordance with well-known
conventional techniques.
Radial mounting flanges 89 are shown in the specific illustrated
embodiment integrally formed on the housing portion 14 in abutting
engagement with the body 12 for quick and easy mounting of the pump
10 to a wall of a second tank 90.
For illustrative purposes, the tank 90 is shown having a suitable
heating unit 91, although it is to be understood that the dispenser
could be easily modified to permit tank 90 to serve in a different
capacity, e.g., wherein another cold liquid is desired to be mixed
with the refrigerated concentrate to provide a blended, cold
beverage.
In this specifically illustrated first embodiment, water will be
understood to be contained in tank 90, and the water, like the
concentrate, is desirably maintained at a uniformly controlled
preselected temperature with minimal heat transfer between the
water and the concentrate. For this purpose, the water tank 90 is
arranged in spaced isolated relation to the concentrate tank 36.
The body 12 and its inlet fitting 86 are received within the
confines of the water tank 90 with the body 12 being in good
heat-conducting relation to the heated water contained within the
tank 90.
To operate the pump 10 at high-speed dispensing cycles with minimal
energy requirements, as well as to provide for minimum water
consumption, a common supply and tank return conduit 92 is
connected in permanently open communication with the operating
compartment 84 for supplying tap water under pressure to drive the
piston subassembly from its loaded position (FIGS. 1 and 3) to its
discharged position (FIG. 2). Thereafter, the spent tap water
returns from the operating compartment 84 via conduit 92 to the
water tank 90 to be heated such that it is conditioned to be
dispensed in a subsequent cycle. Moreover, the fluid circuit of the
preferred embodiment is particularly suited for operation wherein
ordinary city water is supplied at approximately 35 p.s.i. to 15
p.s.i. gage pressure.
More specifically, the supply and tank return conduit 92 is
connected to an open service port 94 in a solenoid-operated main
flow control valve 96. The main control valve 96 has a normally
closed inlet port 98 communicating with an ordinary water supply
line 100, preferably provided with a pressure-regulating valve 102,
and a normally open outlet port 104 of the main control valve 96 is
connected with the water tank 90. Immediately downstream of the
pressure-regulating valve 102 is a branch inlet line 105 for
supplying water to the tank 90, excessive flow being accommodated
by an overflow line 103 connected to a suitable drain, not shown.
The inlet water is controlled by a float-operated valve 106 in the
line 105 to assist in maintaining a substantially constant volume
within the tank 90.
The main control valve 96 is provided with suitable electrical
connections to be energized in response to a demand signal in a
well-known manner. Energization of the main valve 96 causes a valve
member 107 to shift from an OFF position shown in FIG. 1 to an ON
position shown in FIG. 2, closing outlet port 104 to the water tank
90 and simultaneously opening inlet port 98 to direct water under
full line pressure through service port 94 and conduit 92 into the
operating compartment 84 of the pump 10. Pistons 18 and 20 are
immediately thrust forward against the spring force into discharged
position to simultaneously dispense cold concentrate and hot water
from the pump 10 through their respective outlets 32 and 88.
During this power stroke, the fluid circuit inlets to the
concentrate and water compartments 80, 82 of the pump 10 are
closed. While the check valve 34 effectively prevents reverse flow
of concentrate into tank 36, the inlet 86 to the water compartment
82 is closed off to the water tank 90 by a valve member 108 of a
solenoid-operated auxiliary control valve 110 seating against a
normally open working port 112 between a pump inlet line 114 and a
hot water conduit 116 extending upwardly in the tank 90 for
conducting hot water from the top of the tank 90 into the water
compartment 82 of the pump 10. Although the auxiliary control valve
110 is normally open, it is energized in phase with the main
control valve 96 to close off the inlet 86 between the pump 10 and
the tank 90 during the power stroke of the pump.
Upon deenergizing the control valves 96 and 110, auxiliary valve
110 opens working port 112 connecting water compartment 82 to the
tank 90, and the main valve 96 returns to its normal position shown
in FIG. 1, closing inlet port 98 against the full line supply
pressure. Thus, it will be seen that piston 18 is returned under
the force of the return spring 72 after the working port 112 of the
auxiliary control valve 110 shifts back to its normally opened
position and the main control valve 96 shifts to close off the
supply water and open the outlet port 104, whereby the spent raw
water in operating compartment 84 immediately discharges into the
water tank 90 via the permanently open supply and return tank
conduit 92 upon return of the water piston 18 into loaded position.
Accordingly, a normally open passageway under normal atmospheric
pressure is established between the water compartment 82 and the
water in the tank 90 before piston 18 returns under the action of
the return spring 72.
While the water in the tank 90 may be heated to a temperature near
boiling, any tendency of the water in the conduit 114 to "flash" or
vaporize within a partially evacuated water compartment 82 during a
return stroke of the pistons is completely eliminated, thereby to
overcome a problem normally associated with the use of conventional
pressure-responsive check valves in conduits such as at 116. Such
problems are particularly troublesome at high elevations when even
a slight suction in the water compartment 82 tends to cause
vaporization of hot water past a conventional check valve. The
above-described construction utilizing the disclosed
solenoid-operated auxiliary control valve 110 thus serves to ensure
a uniform volume discharge of water in metered quantities from the
pump 10 and avoids even slight variations in the volume of water
being discharged during a succession of servings.
During this return stroke, the pressure in the concentrate and
water compartments 80 and 82 drops and the resultant differential
pressure causes new charges of concentrate and water to be
automatically injected into the pump 10 through their respective
inlets 30 and 86, thereby conditioning the pump 10 for the next
dispensing cycle. Due to the above-described diaphragm mounting of
the water piston 18, the return stroke of the pump 10 is
accomplished in about 2 seconds. A bleed passage 117 is formed in
spacer plug 52 to provide pressure relief behind the water piston
(FIG. 2). By virtue of the common supply and return conduit 92, the
need for complex valving normally associated with apparatus of this
type is eliminated while additionally minimizing the number of
moving parts.
The return discharge of the spent raw water materially assists in
maintaining a water supply of constant volume and of a closely
controlled uniform temperature in tank 90. To ensure that the
dispenser can be operated under "dry stand" conditions even when a
drain such as at 103 is unavailable to pipe off overflow water, a
predetermined differential in the volume of cold and hot water on
opposite sides of the water piston 18 is provided by spacer plug
52. That is, the volume of relatively cold raw water required to
fill the operating compartment 84 to drive the piston 18 is less
than the volume of hot water which fills the water compartment 82.
Accordingly, less cold water will be discharged into tank 90 during
a return stroke of the piston 18 than the volume of hot water
removed from tank 90 to fill the water compartment 82 for
subsequent discharge. The volume differential between the operating
compartment 84 and the water compartment 82 thus compensates for
the volume expansion of the raw water discharged into tank 90 as
the temperature of the raw water is increased to be conditioned to
be drawn into the water-metering compartment 82. Such construction
also serves to maintain a substantially constant liquid level in
the tank 90 even when a number of servings are being made in
relatively quick succession. However, it will be appreciated that
steady, prolonged operation of a pump having the disclosed
differential in its water and operating compartments would
gradually empty the tank 90, and the provision of the previously
described valve 106 serves to maintain the desired liquid level in
the tank 90.
Referring now to FIG. 4 in conjunction with FIGS. 1 and 2, the
outlet fittings 32 and 88 from the concentrate and water
compartments 80 and 82 are connected by outlet lines 118 and 120 to
a serving nozzle 122, a suitable check valve 124 being provided in
the water outlet line 120 downstream of the pump 10 to prevent
water flowing back into water compartment 82 during the return
stroke of the pump 10.
Specifically, the serving nozzle 122 is provided with an adapter
126 connected to the outlet line 118. The adapter 126 is fitted
within a tubular housing 128 and secured in position by a nut 130
threadably connected to the housing 128. At the lower axial end of
the adapter 126, a sleeve 132 is fitted within the housing 128 for
receiving a ball 134 serving as a check valve with the ball 134
being continuously urged toward sealing engagement with the lower
axial end of the adapter 126 under a biasing force of a coil
compression spring 136 seated on a reduced collar portion of a
perforated seal holder 138.
Thus, the outlet line 118 is normally closed off from a mixing
chamber 140 formed within the serving nozzle 122, while yet
permitting one-way flow of concentrate into the mixing chamber 140
during a power stroke of the pump 10, whereby measured quantities
of concentrate and water are turbulently mixed before being
dispensed as a blended beverage through a discharge orifice 141 at
a downstream end of the nozzle 122. Fluidtight connections between
the above-described cooperating parts are ensured by the provision
of suitable elastomeric O-ring seals such as at 139.
As will be recognized by those skilled in the art, a longstanding
difficulty in utilizing a concentrate such as a coffee or tea
concentrate, soup syrups, beer and other liquid beverage
concentrates is that the concentrate or syrup solidifies or is
chemically changed upon being exposed to air and essentially forms
a high-grade protein glue. To overcome this objectionable
difficulty, a lipped seal 142, formed of a tough resilient
material, is mounted inside the lower axial end of the housing 128
and maintained in place by the seal holder 138, and an expandable
tip 144 is provided for the seal 142 to project into the mixing
chamber 140 such that the tip 144 is disposed in the water path
downstream of the water inlet to the mixing chamber 140.
By virtue of this construction, the seal 142 directs concentrate
flow into the nozzle 122 during a power stroke of the pump 10 while
otherwise effectively preventing air passing upstream of the seal
142 from the mixing chamber 140 as well as minimizing undesired
concentrate leakage into the mixing chamber. The seal 142 is
relieved from the pressure head of the concentrate in the outlet
line 118 by the above-described ball check arrangement 134, and
with the tip 144 being disposed in the water path, it will be seen
that the seal tip 144 is provided a water wash to prevent excessive
accumulation of concentrate and ensure a dependable controlled
delivery of the beverage concentrate at the serving nozzle 122.
Referring now to another embodiment of the dispenser pump as shown
in FIGS. 5-9, by virtue of the above-described construction and
arrangement of parts, an additional, third metering compartment 200
is readily formed in the pump 202 for dispensing three different
fluids with minimal structural changes to the body of the pump
202.
The third metering compartment 200 is shown defined in part by an
imperforate sleeve 204 coaxially fixed within the chamber 206
between the rear fluid compartment 208 and the forward fluid
compartment 210, and a piston 212 is received within the sleeve 204
and secured on a forward end of hub 214 of rear piston 216 for
simultaneous reciprocable movement therewith. As in the previous
embodiment, piston 216 separates the rear fluid compartment 208
from the rear operating compartment 218.
To ensure that any undesired heat transfer among the fluids to be
dispensed is minimized, the forward piston 220 is secured by a pin
221 to a rearwardly extending body 222, and an intermediate
metering pump housing portion 224, also of extended length and
preferably formed of a material such as plastic having low thermal
conductivity, is suitably secured between the end housing portions
226 and 228 surrounding compartments 208 and 210. In the
illustrated preferred embodiment, the forward piston 220 includes
an elongated body 222 having a length greater than its stroke. A
piston cup seal 230 at an end of the piston 220 prevents fluid flow
between compartments 200 and 210 past the piston 220.
A check valve housing 232 is threadably secured to the intermediate
housing portion 224, and intake and discharge check valves 234, 236
are fitted within the check valve housing 232 for communicating
with a passage 238 connecting to the third metering compartment 200
of the pump.
To provide lubrication for the piston 220 in an essentially
self-lubricating manner while yet minimizing any unintended heat
transfer between high- and low-temperature portions of the pump, a
minimal clearance of predetermined dimension, say, not greater than
0.005 inch may be intentionally introduced at 240 between the
forward piston body 222 and its guide sleeve 242 for maintaining
therebetween a thin annular lubricating film of fluid from
compartment 200. The essentially negligible mass of the fluid film
not only eliminates any turbulence but also prevents unacceptable
heat transfer through the film.
Thus, when the piston subassembly moves forwardly toward a
discharged position, proportionally metered fluid will
simultaneously flow through the discharge check valve 236 at the
time the rear and forward compartments 208 and 210 are being
discharged, to make a blended three part mixture. When the piston
subassembly returns, the intake check valve 234 permits compartment
200 to be filled. Intake and discharge from the other metering
compartments 208, 210 and the operating compartment 218 is effected
as described in the previous embodiment.
If the dispenser pump is to be used for dispensing a variety of
cold drink mixtures in blended proportions, a relatively high rate
of heat exchange may be desired between the pump-housing portions,
and in this regard still another modification of the metering pump
housing is shown in FIG. 6 wherein a metal extension sleeve 244 of
high thermal conductivity is threadably secured to the body of an
intermediate housing portion 246 which, if desired, also may be
formed of metal or a similar material having a low resistance to
heat transfer to promote such heat transfer between the housing
components of the metering pump.
The body of the forward housing portion 228 may also be extended in
length to readily permit the housing portion to be positioned in
its entirety within a heated or refrigerated part of the dispenser
in spaced isolated relation to the intermediate housing portion 224
of the pump.
When it is also desired to locate the concentrate discharge check
valve (such as that shown at 134 in the previous embodiment) in a
remote position from the discharge outlet of the dispenser, an open
capillary line such as at 248 is preferably connected to the
dispenser outlet (not shown in FIG. 5). Capillary action is relied
upon to hold concentrate in the line, and the concentrate
compartment, e.g., the forward compartment 210 of the illustrated
pump, is provided with a suitably modified outlet incorporating a
pressure-responsive mechanical check valve 250 at the forward
extremity of the chamber 210.
To reduce any tendency of a portion of the concentrate remaining in
the forward compartment 210 for any prolonged period of time, the
throw adjustment device 252 disclosed in FIG. 5 provides an
additional advantage ensuring that the forward piston 220 will
always travel to the forward extremity of the chamber 206 during
each power stroke of the pump regardless of the adjusted position
of the tubular throw adjusting screw 254. For this reason, the
screw 254 is adjustably mounted in fixed relation to the end wall
255 of the pump 202 to provide a variable stop limiting the return
of the piston subassembly from discharged to loaded positions when
piston shaft 256 engages end 257 of screw 254. The latter is
releasably locked by a clamp nut 258 which upon being loosened from
a fixed nut 259 permits longitudinal adjustment of the screw 254
coaxially within a tubular stem 260 of a fluid displacement member
or piston 262 fixed within the movable piston hub 214. Forward
movement of the piston subassembly terminates when piston 212
engages an internal boss 264 within the intermediate housing
portion 224. It will also be noted that both sides of the piston
262 may be desirably wetted by virtue of the tubular screw 254
which is suited to extend beyond the end wall 255 for immersion in
a fluid tank such as tank 90 in the first embodiment.
Such construction ensures that only a minimal amount of concentrate
remains in the pump 202 after each power stroke thereby providing
for self-purging and further minimizing any possibility of a
chemical change in the concentrate which might affect the nature of
the beverage being served, particularly those beverages which have
only a narrow latitude of taste tolerance.
As in the previously described embodiment, the diameter of the
displacement piston 262 is of a predetermined size, much like that
of the spacer plug 52, to provide a desired differential in the
volumetric quantities of the fluids which are to be passed through
the pump 202 on opposite sides of rear piston 216. The displacement
piston stem 260 is shown threadably secured to the nut 259 to fix
the displacement piston 262 in position within the chamber 206.
Adjustment of the effective maximum volume of the operating
compartment 218 may be effected by providing a displacement piston
of a different diameter, and adjusting the inside diameter of the
piston hub 214 correspondingly.
Additional modifications which will be noted in the second
embodiment of the pump 202 include a variety of different piston
seal constructions. A piston cup arrangement is shown provided on
the relatively large rear piston 216 which incorporates
back-to-back cup seals 266, 268 of C-shaped half-section,
preferably of plastic, secured between a pair of plates 270, 272
clamped in position against a shoulder 274 of the piston hub 214 by
means of a nut 276 threaded onto the rear end of the piston hub
214. The diameter of the plates 270, 272 are dimensioned to provide
a preselected clearance relative to the inside wall of the rear
housing portion 226 whereby the perimeter of each piston cup seal
266, 268 readily expands under pressure radially outwardly against
the cylinder wall to provide a reliable seal of increased
integrity, while readily providing sliding contact within the rear
housing portion 226.
Another modification of a piston seal arrangement is shown wherein
a slipper ring 278 (FIGS. 5 and 7) is fitted about the piston 212
received in the third metering compartment 200. It will be noted
that a prestressed O-ring 280 is fitted within a circumferentially
extending groove 282 in the piston 212, and a plastic slipper ring
278 of U-shaped half section is fitted over the O-ring 280 to
extend about the piston 212, providing a dry, self-lubricating
bearing surface for sliding contact with the inside wall of the
sleeve 204.
Still another modified piston cup seal construction is shown formed
on the displacement piston 262 and on the forward piston 220. In
both constructions, cup seals such as at 230 and 284 are fixed
coaxially of their respective pistons in contact engagement with
their cylinder walls to effectively prevent fluid leakage past the
pistons regardless of whether the piston is intended to be fixed or
slidably mounted within the chamber 206 of the pump 202.
Each of the above-described piston seal constructions are
preferably formed of a suitable, commercially available, dry
bearing plastic material exhibiting low-abrasive characteristics
and minimal deformation under load while possessing high wear
resistance and high compressive strength over a wide range of
temperatures to provide a suitable low-friction piston seal.
An alternate valve control system for automatically introducing
controlled quantities of fluid on a demand basis into a tank is
also shown in FIGS. 8 and 9 in conjunction with this second
embodiment. A support bracket 286 is secured to a sidewall of a
tank 288 (which could be a tank similar to that of tank 90 in the
first embodiment) to provide a fulcrum for a generally L-shaped
pivot arm 290 of a float 292 which causes the arm 290 to move
toward and away from the sidewall of the tank 288 respectively in
response to the float 292 being lowered and raised by the fluid
level (such as indicated by broken line 294) within the tank
288.
To automatically control the fluid level within the tank 288, a
solenoid operated control valve 296 is provided in a supply line
298 leading to a feed tube 300 for introducing supply fluid to the
tank 288 from an outside source. To selectively open and close the
control valve 296, a magnetically actuated reed switch 302 is
connected in series with a suitable source of electrical power (not
shown) and with the solenoid winding of the control valve 296
whereby the latter will be operated in response to movement of the
float assembly. Specifically, a magnet 304 carried on the float arm
290 causes the reed switch 302 to close and open when the magnet
304 is moved toward and away from the sidewall of the tank 288 by
the action of the float 292, thereby to automatically open the
supply line 298 when the float 292 is lowered to a predetermined
level and shut off the flow of supply fluid when the increased
height of the fluid within the tank 288 raises the float 292 to a
preselected level.
In view of the above-described embodiments it will be seen that a
dispenser can be readily constructed in accordance with this
invention for dispensing metered quantities of a plurality of
different fluids each of which can be either hot or cold, depending
on the requirements of the beverage desired to be dispensed. The
beverage dispenser of this invention will be seen to be of rugged,
compact construction which is quick and easy to assemble in
addition to being capable of providing high speed, dependable
operation over extended periods of time with minimal maintenance
and service requirements.
As will be apparent to persons skilled in the art, various
modifications, adaptations and variations of the foregoing specific
disclosure can be made without departing from the teachings of the
present invention.
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