U.S. patent number 3,596,675 [Application Number 04/888,115] was granted by the patent office on 1971-08-03 for overflow control system for automatic beverage brewer.
This patent grant is currently assigned to Reynolds Products, Inc.. Invention is credited to Harvey R. Krueger, Arthur A. Morgan.
United States Patent |
3,596,675 |
Krueger , et al. |
August 3, 1971 |
**Please see images for:
( Certificate of Correction ) ** |
OVERFLOW CONTROL SYSTEM FOR AUTOMATIC BEVERAGE BREWER
Abstract
There is disclosed herein an overflow control system for use in
an automatic beverage brewer or the like, comprising, in
combination, a tank for holding fluid therein, discharge means
associated with the tank for discharging fluid therefrom, fluid
inlet means including first valve means for introducing fluid into
the tank when the first valve means is in an open position, means
for operating the first valve means to the open position, means for
operating the first valve means to a closed position after a
predetermined quantity of fluid has been introduced into the tank,
and magnetically controlled valve means disposed in the fluid inlet
means and having a normally open position permitting fluid to flow
therethrough and into the tank so long as the first valve means is
in the open position and having a closed position preventing the
flow of fluid to the tank, the magnetically controlled valve means
being operable to the closed position thereof in response to the
introduction into the tank of a quantity of fluid in excess of the
predetermined quantity, thereby to prevent flooding of the
tank.
Inventors: |
Krueger; Harvey R.
(Carpentersville, IL), Morgan; Arthur A. (Palatine, IL) |
Assignee: |
Reynolds Products, Inc.
(Rolling Medows, IL)
|
Family
ID: |
25392548 |
Appl.
No.: |
04/888,115 |
Filed: |
December 18, 1969 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
|
756592 |
Aug 30, 1969 |
3527172 |
|
|
|
708121 |
Feb 26, 1968 |
3443508 |
|
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Current U.S.
Class: |
137/389 |
Current CPC
Class: |
A47J
31/461 (20180801); A47J 31/057 (20130101); A47J
31/54 (20130101); Y10T 137/7297 (20150401) |
Current International
Class: |
A47J
31/46 (20060101); A47J 31/04 (20060101); A47J
31/44 (20060101); A47J 31/54 (20060101); A47J
31/057 (20060101); F16k 003/18 () |
Field of
Search: |
;137/389,400,401,402,414,334,340,341 ;251/45,65 ;99/282,300 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Klinksiek; Henry T.
Parent Case Text
This application is a division of the copending application, Ser.
No. 756,592, filed Aug. 30, 1969, now U.S. Patent No. 3,527,172,
for OVERFLOW CONTROL SYSTEM FOR AUTOMATIC BEVERAGE BREWER, which is
a continuation-in-part of U.S. application Ser. No. 708,121, filed
Feb. 26, 1968, now U.S. Pat. No. 3,443,508, entitled Automatic
Beverage Brewer.
Claims
What we claim is:
1. A fluid control system comprising, in combination, a tank for
holding fluid therein, discharge means associated with said tank
for discharging fluid therefrom, fluid inlet means including first
valve means for introducing fluid into said tank when said first
valve means is in an open position, means for operating said first
valve means to an open position, means for operating said first
valve means to a closed position after a predetermined quantity of
fluid has been introduced into said tank, and magnetically
controlled valve means disposed in said fluid inlet means and
having a normally open position permitting fluid to flow
therethrough and into said tank so long as said first valve means
is in the open position and having a closed position preventing the
flow of fluid to said tank, said magnetically controlled valve
means being operable to said closed position thereof in response to
the introduction into said tank of a quantity of fluid in excess of
said predetermined quantity, thereby positively to terminate the
flow of fluid to said tank regardless of the position of said first
valve means.
2. The fluid control system set forth in claim 1, wherein said
first valve means comprises an electrically controlled valve.
3. The fluid control system set forth in claim 2, wherein said
magnetically controlled valve means is disposed in said water inlet
means downstream of said electrically controlled valve.
4. The fluid control system set forth in claim 1, wherein said
discharge means includes means operative to prevent discharge of
fluid from said tank until said predetermined quantity of fluid has
been introduced therein.
5. A fluid control system comprising, in combination, a tank for
holding fluid therein, discharge means associated with said tank
for discharging fluid therefrom, fluid inlet means including first
valve means for introducing fluid into said tank when said first
valve means is in an open position, means for operating said first
valve means to said open position, means for operating said first
valve means to a closed position after a predetermined quantity of
fluid has been introduced into said tank, an overflow line
connected to said tank for directing excess fluid from said tank, a
vessel positioned to receive fluid from said overflow line, a float
disposed in said vessel and operative between upper and lower
positions of operation in response to the introduction of fluid
from said overflow line into said vessel, said float carrying first
magnetic means thereon, a casing having an inlet and an outlet
secured to said vessel, said vessel and said casing defining a
chamber therebetween, apertured means disposed within said chamber
between said inlet and outlet, second magnetic means disposed
within said chamber between said vessel and said apertured means
and being reciprocally movable between an obstructing position of
engagement with said apertured means for preventing the flow of
fluid through the aperture thereof at substantially one end limit
of movement thereof and a nonobstructing position at substantially
the opposite end limit of movement thereof permitting the flow of
fluid therethrough when said first valve means is in the open
position, said first magnetic means carried by said float being
operative to maintain said second magnetic means in the
nonobstructing position thereof only so long as said float is in
the lower position thereof, whereby the introduction of a quantity
of fluid into said tank in excess of said predetermined quantity
causes excess fluid in said tank to flow into said vessel and to
move said float to the upper position thereof and thereby cause
said second magnetic means to shift to the obstructing position
thereof so as positively to terminate flow of fluid through said
fluid inlet means into said tank.
6. The fluid control system set forth in claim 5, wherein said
sidewall of said vessel includes a vertically extending pocket
formed therein for receiving the lower end of said overflow line
and a passage in said side between said pocket and said vessel
whereby water from said overflow line enters said vessel from the
sidewall thereof and thereby does not interfere with upward
movement of said float.
7. The fluid control system set forth in claim 5, wherein said
vessel and said float and said casing are all formed of a
nonmagnetic material.
8. The fluid control system set forth in claim 5, wherein said
bottom wall of said vessel includes means integrally formed therein
defining a guide surface for said second magnetic means and stop
means integrally formed therein for preventing said second magnetic
means from moving with said first magnetic means carried by said
float when said float rises in response to the introduction of
water into said vessel.
Description
This invention relates generally to an overflow fluid control
system and more particularly to an overflow control system adapted
for use in an automatic beverage brewing machine such as the type
capable of automatically brewing predetermined amounts of
coffee.
Generally, an automatic beverage brewer includes a water inlet
system for automatically introducing a predetermined quantity of
cold water to a water tank, means for heating the water in the
tank, and means for delivering the heated water to a spray or
discharge head to be sprayed or discharged over a predetermined
amount of beverage producing material, whereby extract of the
material is brewed and delivered to a beaker or the like for
consumer usage.
In the majority of automatic beverage brewers now manufactured, an
electrically operated valve and suitable controls are provided for
introducing a predetermined quantity of cold water from the
municipal supply system into the water heating tank of the beverage
brewing machine. Such valves and controls are also used in other
machines which are connected to a source of fluid and are
cyclically operated, such as dish washers and clothes washers. It
is desirable to provide suitable safety devices in all such
machines which will operate in the event of malfunction of the
electrically operated valve, and particularly to terminate the
input flow of water to the receiving tank should the water in the
tank exceed a predetermined quantity, thereby to prevent the tank
from overflowing and damaging the machine.
Accordingly, it is a primary object of the invention to provide an
overflow control system capable of preventing entry of fluid into a
receiving tank in the event of a malfunction in the normal fluid
inlet system which causes fluid in the tank to exceed a
predetermined quantity.
It is a further object of the invention to provide an overflow
control system which employs a novel float-operated magnetically
controlled valve as part of the water inlet system, said valve
being operative to terminate flow of water to the water tank in the
event the amount of water within the tank exceeds a predetermined
quantity.
It is a further object of the invention to provide an overflow
control system employing a magnetically controlled valve means in
an automatic type water system, the machine further employing a
unique water inlet control arrangement that operates without a
timer or scale to control the input quantity of water to the
machine.
It is a further object of the invention to provide an automatic
beverage brewer of the character described which includes a
hydraulically operated discharge valve to control discharge of hot
water from the water tank of the machine, the discharge valve being
controlled by operation of the water inlet system so that while
cold water is flowing into the tank the valve remains closed to
prevent discharge of hot water therefrom.
Still another object of the invention is to provide an improved
float-operated magnetically controlled valve which is of a positive
and rapid action and which is economical of manufacture and is
relatively compact in size.
In accordance with one aspect of the invention, there is provided
an automatic beverage brewing machine for brewing coffee or the
like, the machine including a water tank having a sidewall and a
bottom wall and a top wall. Thermostatically controlled heating
means is disposed within the water tank for heating and maintaining
water therein at a beverage brewing temperature. Discharge means is
associated with the water tank for discharging hot water therefrom
and means is provided for receiving a beverage producing material
to be covered by hot water from the discharge means. The automatic
machine also includes water inlet means including an electrically
controlled valve for introducing cold water into the tank to cause
hot water in the tank to be discharged therefrom in an amount
corresponding to the quantity of cold water introduced thereto;
means being provided for opening the electrically controlled valve
to cause cold water to flow into the water tank, and means being
provided for closing the electrically controlled valve after a
predetermined quantity of cold water has been introduced into the
water tank. In accordance with the invention, float-operated
magnetically controlled valve means also is disposed in the water
inlet means, the magnetically controlled valve means having a
normally open position permitting water to flow therethrough and
into the water tank so long as the electrically controlled valve is
in the open position and having a closed position preventing the
flow of water to the water tank. The magnetically controlled valve
means is operable to the closed position thereof in response to
introduction into the water tank of a quantity of cold water in
excess of the predetermined quantity of cold water, thereby
positively terminating the inlet flow of water so as to prevent
flooding of the machine.
Further features of the invention pertain to the particular
arrangement of the elements of the automatic beverage brewing
machine and the overflow control system therefor whereby the
above-outlined and additional operating features thereof are
attained.
The invention, both as to its organization and method of operation,
together with further objects and advantages thereof, will best be
understood by reference to the following specification when taken
in connection with the accompanying drawings, in which:
FIG. 1 is a perspective view of an automatic beverage brewing
machine embodying the present invention;
FIG. 2 is an enlarged view in vertical section of the beverage
brewing machine of the present invention taken along the line 2-2
of FIG. 1, and illustrating the beverage brewing machine
preparatory to a brewing cycle with the water tank partially full
and a beverage producing material in the basket provided
therefor;
FIGS. 3 and 4 are enlarged views of the encircled area of FIG. 2,
illustrating the construction of the hydraulically operated
discharge valve in greater detail;
FIG. 5 is an enlarged plan view taken along the line 5-5 of FIG. 2,
illustrating the vessel forming part of the float-operated
magnetically controlled valve means of the present invention, with
the float removed therefrom;
FIG. 6 is a sectional view of the float-operated magnetically
controlled valve means of the present invention, taken along the
line 6-6 in FIG. 5 and illustrating the position of the various
parts thereof prior to the initiation of a brew cycle of the
machine;
FIG. 7 is a sectional view similar to FIG. 6, illustrating the
position of various parts of the magnetically controlled valve
means in an open position when water is being introduced into the
machine;
FIG. 8 is a view similar to FIGS. 6 and 7, illustrating the
position of the various parts of the magnetically controlled valve
means in the closed position; and
FIG. 9 is one form of electrical circuit which may be employed with
the automatic beverage-brewing machine disclosed herein.
Referring now to the drawings and more particularly to FIGS. 1 and
2 thereof, there is illustrated an automatic beverage brewing
machine 10 which may be used for brewing coffee or the like. The
beverage-brewing machine 10 includes a generally rectangular base
portion 11 having a forward control panel 12. A plurality of
adjustably mounted legs 13 is provided in the base 11 for properly
seating the machine on a counter top or the like.
A lower heating unit 14 is provided immediately below the upper
surface of the base 11 and is disposed adjacent the front end
thereof. The lower heating unit 14 is adapted to receive an
associated beverage receiving beaker thereon. A lighted switch 15
is provided on the control panel 12 for controlling operation of
the lower heating unit 14.
The machine 10 further includes a lower housing designated
generally as 16, defined by an upstanding front wall 17, a pair of
sidewalls 18 and a rear wall 19. An upper housing 20 is mounted on
the lower housing 16 and includes the forwardly extending sidewalls
21, a front control panel 22, a rear wall 23, a top wall 24 and a
bottom wall 25. As seen in the drawings, the upper housing 20 is
substantially coextensive in length to the base 11.
The top wall 24 of the upper housing is provided with an upper
heating unit 26 disposed substantially adjacent to the front end
thereof. The upper heating unit 26 is provided with a centrally
disposed thermal-responsive switch 27, a manual control switch 26
being provided on the front control panel 22 for controlling
operation of the heating unit 26. A pilot light 29 is also provided
on the front panel 22 and is energized when the switch 28 is in an
"on" position. A cycle control switch 30 is also provided on the
front panel 22 of the upper housing, depression of the switch 30
effecting operation of the machine in the manner hereinafter
described.
The top wall 24 of the upper housing 20 is further provided with an
opening therein defined by an annular flange 31, (FIG. 2) which
opening is normally closed by a domed cover 32 held in position by
a plate 33 disposed below the top wall and a screw 34 holding the
plate and cover 32 in engagement with the top wall.
The bottom wall 25 of the upper housing 20 is provided with a
raised portion within which is disposed a discharge head 35, the
discharge head being connected to the hot water discharge system as
hereinafter described. The bottom wall 25 is also provided with a
pair of longitudinally extending slides 36 (one only being shown),
the slides 36 being provided to operably position a brew basket 37
below the discharge head 35. In operation, the brew basket 37 is
provided with a filter paper cup containing the beverage-producing
material, in this case ground coffee as shown at 38. An associated
beverage receiving beaker 39 is disposed on the lower heater 14
below the brew basket to receive the coffee extract flowing
therefrom. The discharge head 35 may be of the type illustrated and
described in the copending application of Peterson et al. Ser. No.
736,091, filed June 11, 1968, now U.S. Pat. No. 3,490,356, for
Spray Discharge Head, and assigned to the same assignee as the
present application; and the brew basket 37 may be of the type
illustrated and described in the copending application of Reynolds
et al. Ser. No. 668,384, filed Sept. 18, 1967, now U.S. Pat. No.
3,479,949 also assigned to the same assignee.
The upper and lower housings 16 and 20 cooperate to provide an
enclosure for a water tank 40. The water tank 40 includes a bottom
wall 41 and a cylindrical sidewall 42, the tank 40 being disposed
upon a partition 43 which is provided in the lower housing 16. The
upper end of the water tank 40 is provided with an outwardly turned
annular lip 44. A cover 45 is disposed over the tank 40, the cover
having a downwardly extending annular channel 46 formed thereon
about the periphery thereof adapted to cooperate with the annular
lip 44 on the water tank 40, thereby to prevent lateral movement of
the cover 45 relative to the water tank 40. The cover 45 is
provided with a centrally disposed and upwardly extending annular
flange 47 which defines a centrally disposed opening therein
adapted to receive the upper end of an upstanding tube 50 as
hereinafter described.
A heating coil 60 is disposed within the water tank 40
substantially adjacent to the bottom wall 41 thereof, the terminals
61 of the heating coil 60 extending through the bottom wall 41 of
the water tank and the partition 43 in the lower housing for
connection through a fuse 63 with suitable conductors (not shown)
to a terminal block 63 carried below the partition 43. A
temperature-responsive element or thermostat 65 is disposed within
the water tank 40, the lower end 66 of the thermostat 65 extending
through aligned openings in the bottom wall 41 of the tank and the
partition 43 for connection to a tank thermostat switch 67 in a
conventional manner. The arrangement is such that water is the
water tank 40 is constantly maintained at an elevated temperature.
This makes it possible to promptly draw off a supply of hot water
from the water tank for the purpose of making coffee extract in the
manner to be described.
Provision is made for automatically displacing a predetermined
quantity of hot water from the upper portion of the water tank 40
by introducing an equal amount of water, preferably cold water, in
the lower portion of the water tank; the upstanding tube 50 being
provided for this purpose. The upper end 51 of the tube 50 is
provided with a plurality of nibs (not shown) adapted to engage the
upstanding annular flange 47 of the cover 45, whereby the tube 50
is removably carried by the cover.
The tube 50 extends downwardly within the tank 40, the lower end 52
thereof terminating near the bottom wall 41 of the tank. The upper
end of the tube 50 is provided with a generally rectangular notch
53 which begins below the cover 45 and extends upwardly beyond the
flange 47. The notch 53 places the interior of the water tank 40 in
direct communication with atmosphere and provides for the escape of
air from the upper end of the water tank 40 when hot water within
the tank is upwardly displaced therein in response to the pouring
of cold water through the tube 50. The upper end of the tube 50 is
also provided with a plurality of openings 54 therein which permit
the discharge of air from the tank and also permit water to flow
out of the tube 50 and directly into the tank in the event water
floods the tube and is prevented from entering the tank through the
lower end of the tube.
In a typical construction of the tube 50, the tube itself is formed
of stainless steel and is approximately 85/8 inches long and it has
an outer diameter of approximately 11/4 inches, the wall thereof
being approximately 0.035 inch thick. The openings 54 are
approximately one-quarter inch in diameter with the centers thereof
being disposed approximately thirteen thirty-secondths of an inch
below the upper end of the tube. The relatively large diameter of
the tube provides twofold advantages: (1) it permits rapid
introduction of the cold water to the bottom of the tank without
great turbulence and (2) any liming effect or buildup of scale on
the inner wall thereof will not interfere with the flow of incoming
water as in the case where a tube having a small diameter is
used.
With continued reference to FIG. 2, it will be seen that a
foraminous or screenlike inlet cover 55 including an outer
peripheral flange 56 is secured to the tank cover 45 by a plurality
of screws 57. One sidewall 58 of the inlet cover 55 is provided
with an annular flange 59 which receives one end of a delivery
conduit of the water inlet system hereinafter described, the inlet
cover serving as an air break for the water inlet system to prevent
back siphonage into the inlet water line in the event of a
malfunction therein, such air break being required by virtually all
local ordinances.
Still referring to FIG. 2, it will be seen that the cover 45 for
the tank 40 also is provided with a float actuated switch mechanism
designated generally as 70. The switch mechanism 70 includes a
float 71 disposed within the tank 40 and having an upwardly
extending float stem 72 secured thereto. The float stem 72 extends
through an opening provided therefor in the tank cover 45. A
generally rectangular bracket 73 is rigidly affixed to the cover
45, the bracket having an opening therethrough which receives the
float stem 72 so as to permit reciprocal movement of the float stem
therein. An arm 74 is rigidly secured to the float stem 72 within
the bracket 73 and is movable therewith. The major portion of the
arm 74 is disposed substantially normal to the stem 72, the outer
end of the arm 74 being formed to provide a holding flange within
which is disposed a horizontally extending magnet 75.
Downward movement of the float is limited by engagement of the arm
74 with a generally U-shaped bracket 76. A reed switch 77 is
mounted within the bracket 76 and is operable in response to
movement of the magnet 75 carried by the arm 74. The reed switch 77
includes terminals (not shown) for connection to suitable
conductors. The U-shaped bracket 76 is held in position on the
bracket 73 by a screw 78 which extends through tabs formed on the
bracket 73 and the laterally extending arms of the bracket 76, the
bracket 76 being vertically adjustable relative to the cover 45 by
rotation of the screw 78, whereby the operative position of the
switch 77 can be adjusted. The reed switch 77 may be of the type
manufactured by Hamlin, Inc. as its switch number KRL-2.
In operation, as the hot water rises within the tank 40 and engages
the float 71, the float 71 will rise within the tank causing the
stem 72 also to rise, thereby raising the arm 74 and the magnet 75
mounted therein. When the magnet moves about one-half inch above
the reed switch 77, the reeds therewithin will separate and thereby
break the circuit through the switch. As the water level in the
tank drops and the float 71 descends therein, the magnet 75 will
approach the reeds of the reed switch 77, and, when the magnet is
approximately one-fourth inch away, the magnetic force thereof will
cause the reeds to close and again complete a circuit through the
switch 77. The float actuated switch mechanism 70 is provided to
control an electrically operated water inlet valve for the machine
in a manner hereinafter described, suffice it to say for now that
when the switch 77 is opened it breaks a circuit for the water
inlet valve and terminates the input of cold water to the water
tank.
The hot water discharge system for the machine also is illustrated
in FIG. 2, wherein it is seen that the side wall 42 of the water
tank 40 is provided with an opening therein which is disposed
substantially below the upper end of the water tank and is adapted
to receive and support a discharge block 80 therein, hot water
being delivered from the tank 40 through the discharge block
80.
The discharge block 80 includes a vertically disposed passage 81
extending upwardly from the bottom surface 82 of the block and
terminating as a discharge outlet 83 disposed normal to the passage
81. The discharge outlet 83 extends through the opening in the side
wall of the water tank 40, a rubber gasket 84 being disposed about
the discharge outlet 83 where it passes through the opening thereby
to prevent water from leaking therebetween.
One end of a discharge line 85 is connected to the discharge outlet
83 of the block 80, the other end thereof being connected to a
first inlet of a discharge valve 100, the discharge outlet from the
valve 100 being connected to the spray discharge head 35. As
illustrated, the discharge head 35 is mounted in spaced relation to
the water tank 40 and is disposed below the discharge block 80 in
the side wall of the water tank, the discharge head 35 being
located below the upwardly deformed portion of the bottom wall 25
of the upper housing 20.
It will be understood that upward displacement of hot water within
the tank 40 causes hot water to rise in the passage 81 until it
reaches the discharge outlet 83, at which time hot water will flow
through the discharge block 80, the discharge line 85, the
discharge valve 100 (when open) and the discharge head 35 until the
water level in the water tank drops below the lower surface 83 of
the discharge block. When the water level drops below the lower
surface 82 of the discharge block, to the level indicated as 90 in
FIG. 2, the passage 81 of the discharge block provides an air gap
between the discharge outlet 83 and the bottom surface 82 thereof
which prevents the drawing off of additional water from the water
tank 40. The lowest portion of the discharge outlet 83 and the
lower surface 82 of the block are sufficiently spaced so that the
passage 81 accommodates the expansion of cold water being heated in
the tank without drippage thereof through the discharge outlet
83.
In a typical construction of the discharge block 80, the block
itself is molded of silicone rubber with a hardness of
approximately 0.40 durometer, the passage 81 has an inner diameter
of approximately five-eighths inch, the discharge outlet 83 and the
discharge line 85 each have an inner diameter of approximately
five-sixteenths inch, and the lowest portion of the discharge
outlet 83 is disposed about eleven thirty-secondths of an inch
above the bottom surface 82 of the block. The passage 81 is formed
of a larger diameter than the discharge outlet 83 to insure that a
full stream of hot water enters the outlet 83, whereas if the
passage 81 and the outlet 83 were of complementary diameters, it is
possible that air bubbles might be entrained therein.
The discharge block 80 is suitably positioned in the side wall 42
of the water tank so that the volumetric capacity of the water tank
40 between the lower surfaces 82 of the discharge block and the
actuated position of the float 71 is sufficient to receive at least
about 60 ounces of water when the hot water in the water tank is
displaced to the upper portion of the tank, as indicated by the
dashed line 95 in FIG. 1; the volumetric capacity of the tank 40
below the discharge block 80 being about 6 quarts of water. By
adjusting the float stem 72 in the manner heretofore described, the
capacity of the upper portion of the tank can be varied by
approximately .+-.6 ounces.
The upper portion of the water tank above the discharge block 80 is
intended to have a capacity corresponding to that of the associated
beaker 30, whereby the introduction of a predetermined quantity of
cold water into the water tank 40 will cause a substantially equal
amount of hot water to be upwardly displaced therein and ultimately
discharged as a beverage extract into the beaker 30.
As noted, the discharge line 85 is connected through the discharge
valve 100 to the discharge head 35, the discharge head 35 being
adapted to spray hot water in a plurality of streams at
substantially uniform flow rates and in a particular overall
pattern over the material 36 in the brew basket 37, the head 35
being illustrated and described in the aforementioned copending
application Ser. No. 736,091, filed June 11, 1969, entitled SPRAY
DISCHARGE HEAD.
The discharge valve 100 for controlling discharge of hot water from
the tank 40 is best illustrated in FIGS. 3 and 4. The valve 100
includes a generally T-shaped hollow body 101; one end of the head
of the T providing a first inlet passage 102 adapted to be
connected to the discharge line 85, the opposite end thereof being
formed substantially larger and defining a generally cylindrical
chamber 103 therein. The branch of the T defines a discharge
passage 104 which is adapted to be connected by a conduit 105 to
the inlet side of the discharge head 35.
An inlet fitting designated generally as 110 is rigidly secured to
the body 101 and extends within the chamber 103 thereof. A plunger
designated generally as 120 carrying a molded valve seat 125
thereon is disposed within the chamber 103 for reciprocal movement
relative to the inlet fitting 110 and the inlet passage 102, the
plunger 120 serving as a closure member which precludes flow of
fluid through passage 104 when the plunger is in a closed
position.
To complete the description of the body 101, it will be seen that
the inlet passage 102 is provided with a first shoulder 106 formed
therein immediately to the right of the discharge passage 104. The
inner wall of the body 101 continues as a straight section for a
short distance from the shoulder 106 and then tapers outwardly as
at 107, terminating in a second shoulder 108 which forms the inner
end of the chamber 103. The shoulder 108 is provided with an
inwardly extending lip 109 thereon. The various sections 106
through 109 cooperate with the plunger 120 and with the valve seat
125 carried by the plunger to provide a relatively watertight seal
between these parts so as to prevent leakage of fluid from the
chamber 103 to the inlet passage 102, or in the opposite direction,
the lip 109 providing a relatively small surface area upon which
the valve seat 125 abuts, thereby to provide a good seal
therebetween even under relatively low pressures.
The inlet fitting 110 is provided with an inlet passage 111
therethrough, the outer portion of the fitting 110 being adapted to
be connected by an appropriate connector to a branch conduit 115 of
the water inlet system hereafter described, whereby the inlet
passage 111 is adapted to discharge water against the valve seat
125 and into the chamber 103.
The inlet fitting 110 is provided with a first annular flange 112
which seats within an appropriately provided recess formed in the
end of the valve body 101; the inlet fitting 110 being held in
position by a washer 113 which overlies one portion of the flange
112. The washer 113 is held in position by a screw 114 which
engages an appropriately provided portion of the body 101. The
inlet fitting 110 includes a second annular flange 116 at the inner
end thereof, an O-ring 117 being disposed between the flanges 112
and 116 and the body 101 so as to provide a suitable seal
therebetween. The inner end of the fitting 110 is provided with a
generally cylindrical recess 118 for reasons hereafter
explained.
The plunger 120 includes a generally cylindrical main body portion
121 which is of a diameter only slightly less than the diameter of
the inlet passage 102 and is movable therein. The plunger includes
an annular base 122 formed thereon, the base 122 being of a larger
diameter than the main body portion 121. The plunger 120 further
includes a second cylindrical portion 123 which extends outwardly
from the base 122. The base 122 and the cylindrical portion 123 are
provided to receive and retain the valve seat 125 thereon. A washer
126 holds the valve seat 125 on the plunger 120, the washer 126
overlying the valve seat 125 and being held in position by a
plurality of retaining tabs 124 which are formed in the cylindrical
portion 123 and which overlie the washer 126, thereby to maintain
the valve seat 125 in firm engagement on the plunger 120. The valve
seat 125 is provided with an annular pointed ridge 127, the ridge
127 being provided so as to minimize the surface contact between
the valve seat 125 and the inner surface of inlet fitting 110,
thereby to insure a good seal therebetween under relatively light
pressures. The recessed portion 118 is formed in the inner end of
the inlet fitting 110 to receive the retaining tabs formed on the
plunger when the plunger is in the position shown in FIG. 3,
whereby the ridge 127 of the valve seat can engage the fitting
110.
A compression spring 129 is disposed about the main body portion
121 of the plunger and extends between the lower surfaces of the
annular base 122 and the first shoulder 106 formed in the valve
body, the spring 129 acting to bias the plunger 120 to the right so
that the seat 125 sealingly engages the inner end of the inlet
fitting 110, thereby to prevent entry of water through the passage
111 of the inlet fitting and into the chamber 109.
In operation, when the discharge valve 100 is in the normal "open"
position, with the plunger 120 to the right as shown in FIG. 3, hot
water may flow from the water tank through the discharge block 80,
the discharge line 85, into the inlet passage 102 thereof and out
of the valve 100 via outlet passage 104 and conduit 105 to the
inlet of the discharge head 35, whereupon it will be sprayed
therefrom over the coffee grounds in the brew basket 37.
The discharge valve 100 is operable to a "closed" position when the
plunger 120 is biased to the left, as shown in FIG. 4, at which
time the main body portion 121 of the plunger operates to seal off
the inner end of the outlet passage 104 and thereby prevent the
flow of hot water therethrough. The discharge valve is operated to
the "closed" position thereof by the pressure of cold water flowing
through conduit 115 into the inlet passage 111 of the inlet fitting
110 and against the seat 125, such pressure being developed by the
inlet water system in the manner hereinafter explained.
In a typical construction, the valve body 101 may be formed of a
nylon material sold under the trade name Zytel 31; the valve body
101 being approximately 2.187 inches in length with the center of
the discharge passage 102 thereof being disposed approximately
0.014 inch from the left-hand end of the valve body. The shoulder
106 defining the end of the inlet passage 102 is disposed at
approximately the midpoint of the head portion of the body, and the
passages 102 and 104 are each five-sixteenths inch in diameter. The
shoulder 108 formed in the side wall of the body 101 is disposed
approximately 0.791 inches from the end of the body, the lip 108
being raised approximately 0.020 inches thereon; the tapered
portion 107 being disposed at an angle of approximately 30.degree.
relative to the sidewall of the body, and the sidewall of the body
defining the chamber 103 being approximately 0.640 inches in
diameter.
The inlet fitting 110 is formed of yellow brass, the inlet passage
111 therein being approximately 0.109 inch in diameter. When the
inlet fitting 110 is positioned within the chamber 103, the inner
end thereof is disposed approximately 0.32 inch from the shoulder
108.
The plunger 120 is also formed of nylon as Zytel 31. The main body
portion 121 of the plunger is approximately 0.695 inch in length
and is approximately 0.295 inch in diameter; the base 122 thereof
being approximately 0.065 inch in length and approximately 0.41
inch in diameter; the cylindrical portion 123 being approximately
0.19 inch in length including the retaining tabs 124 and being
approximately 0.190 inch in diameter. The valve seat 125 is formed
of hard rubber such as BUNA-"N" and is approximately 0.65 inch in
diameter and 0.187 inches in height, including the annular ridge
127 thereon. As illustrated in the drawings, the body portions 121
and 123 of the plunger are hollow for molding purposes.
The water inlet system for the machine is illustrated in FIG. 2 and
includes a water supply line 130 which is adapted to be connected
to an available source of cold water. The supply line 130 is
connected through an appropriate fitting 131 to the inlet side of
an electrically controlled valve 135, the outlet of the valve 135
being connected through a conduit 136 to the inlet of a normally
open float-operated magnetically controlled valve 140, the valve
140 forming part of the present invention.
The valve 140 is intended to operate as a safety valve so as
positively to prevent the introduction of cold water to the water
tank 40 in the event of a malfunction of the electrically
controlled valve 135, or some other component of the system, which
malfunction would cause overflow of water from the tank 40.
A conduit 141 connects the outlet of the magnetically controlled
valve 140 to the inlet of a flow restrictor 145 through a T-shaped
fitting 146. The fitting 146 has a branch outlet 147, to which is
connected the conduit 115 which leads to the inlet fitting 110 of
the discharge valve 100. The flow restrictor 145 serves to regulate
the output flow of water therethrough to a relatively uniform flow
rate of approximately 1 gallon per minute, regardless of the inlet
water pressure thereto. The flow restrictor 145 may be of the type
manufactured by the Dole Valve Company as their model No. M-39.
The outlet end of the flow restrictor 145 has a delivery conduit
150 connected thereto which extends upwardly above the water tank
40. The upper end of the delivery conduit 150 is bent to provide a
downwardly directed portion 151 which is disposed within the
flanged opening 59 formed in the sidewall 58 of the inlet cover 55,
thereby to discharge cold water into the upper end of the tube 60
where it flows by gravity to the lower end of the tank 40. By
directing the water discharging from the conduit 150 toward the
side of the tube 50 instead of directly downward, it is possible to
minimize agitation of the hot water in the tank as the cold water
is introduced.
The flow restrictor 145 causes the cold water to be discharged at a
fairly uniform flow rate regardless of the incoming pressure
thereto. When the pressure of the incoming water to the flow
restrictor exceeds a certain value, back pressure is developed
therein which causes some of the entering cold water to be diverted
through the branch 147 of the T fitting and through the conduit 115
to the water inlet passage 111 of the discharge valve 100. The
pressure of the water flowing through the passage 111 and against
the valve seat 125 causes the plunger 120 to move to the "closed"
position thereof illustrated in FIG. 4, whereby the main body
portion 121 of the plunger closes off the discharge outlet 104 and
prevents hot water from flowing therethrough. At this time the
valve seat 125 abuts against the lip 109 formed in the chamber 103
so as to prevent flow of cold water from chamber 103 into the
passage 102.
A pressure of approximately 1 1/2 p.s.i. is required to hold the
plunger 120 in the "closed" position thereof. This pressure will be
developed when the line pressure to the flow restrictor 145 is
approximately 10 p.s.i., whereby the minimum operating pressure for
the machine using components of the type herein described is
approximately 10 p.s.i. The back pressure created by the flow
restrictor 145 generally increases in direct ratio to the increase
in line pressure thereto.
In addition to providing the back pressure which controls the
discharge valve 100, the flow restrictor 145 also insures that the
water will flow into the water tank at a substantially uniform
rate, whereby the water inlet cycle for the machine 10 will be
relatively constant. The flow restrictor 145 also prevents rapid
flooding of the tank should the inlet supply of water be at a high
pressure.
The water inlet system and the hot water discharge system cooperate
to admit only a predetermined quantity of water to the tank 40. In
normal operation, when the electrically controlled valve 135 is
energized, cold water flows through the supply line 130, the valve
135, conduit 136, valve 140 and into flow restrictor 145, wherein
the back pressure created therein causes some of the incoming water
to flow through the T passage 147 and thence through the conduit
115 so that it impinges upon and applies a constant pressure to the
seat 125 of the plunger 120 in the discharge valve 100, the
pressure being sufficient to cause the plunger 120 to move to the
"closed" position thereof.
Concurrently with the closing of the discharge valve 100, cold
water also flows out of the flow restrictor 145 through the
delivery conduit 150, whereupon it is discharged through the inlet
cover 55 into the upper end of the upstanding tube 50. The incoming
cold water flows downwardly through the tube 50 to the bottom of
the tank and causes hot water contained therewithin to be upwardly
displaced within the tank. As the hot water in the water tank rises
some of it will flow through the discharge block 80, the discharge
line 85 and into the inlet passage 102 of the discharge valve 100.
However, the pressure of the water flowing through the discharge
head 80 is equal only to the head pressure of that water within the
water tank which is disposed above the discharge block 80. The head
pressure of the water and the force of the compression spring 129
on the left side of the plunger 120 are substantially less than the
pressure of the cold water flowing through conduit 115 and against
the seat 125 of the plunger 120, whereby the plunger 120 remains
closed and prevents the discharge of hot water through the valve
100 and the discharge head 35.
Because the hot water is prevented from flowing out of the water
tank 40 by the discharge valve 100 while the electrically
controlled inlet valve 135 is open, cold water continues to flow
into the bottom of the tank causing the hot water in the tank to
rise above the discharge block 80 and to raise the float 71. The
float stem 72 also rises and lifts the magnet 75 carried thereby
away from the reed switch 77, whereby the switch 77 opens to break
the electrical circuit to the valve 135 and thereby close same to
prevent further introduction of cold water to the tank.
When the electrically controlled valve 135 closes, the back
pressure developed by the flow restrictor 145 terminates and
relieves the water pressure against the seat 125 of the plunger
120, whereby the head pressure of the hot water in the inlet
passage 102 and the force of the spring 129 on the left side of the
plunger 120 cause it to move to its normally open position as shown
in FIG. 3, at which time the hot water can flow through the valve
120 via the discharge passage 104, through the conduit 105 and
through the discharge head 35 and over the coffee grounds disposed
in the brew basket 37. The water will continue to flow out of the
discharge head until the water level within the tank drops to just
below the bottom surface 82 of the discharge block 80, as indicated
at 90 in FIG. 2, the air drawn into the tank through the notch 83
and the openings 54 in the upper end of the tube 50 providing an
air gap in the passage 82 so that the flow of hot water from the
water tank positively terminates.
As heretofore noted, discharge of hot water from the tank 40
terminates when the water reaches the level 90 illustrated in FIG.
2. Because the bottom surface 82 of the block 90 is disposed below
the discharge outlet 83 therein, the standby level of water within
the tank 40 is normally disposed below the discharge outlet 53,
and, as previously described, the distance between the discharge
outlet 83 and the bottom surface 82 of the block 80 is sufficient
to accommodate expansion of the cold water within the tank upon the
heating thereof to prevent drippage of water through the discharge
outlet 83.
As previously noted, it is a primary object of the invention to
provide an overflow control system for use in a beverage brewing
machine of the type herein described, the overflow control system
serving positively to terminate the flow of cold water into the
water tank 40 in the event the amount of water therein exceeds a
predetermined amount. To this end, the float-operated magnetically
controlled valve means 140 has been provided.
To operate the valve means 140 in the manner hereinafter described,
the water tank 40 is provided with an overflow pipe 155, the upper
end of the pipe 155 being disposed at a predetermined maximum
permissible water level within the tank. The pipe 155 extends
through the bottom wall 41 of the tank 40 and the partition 43 for
discharge into an overflow vessel 160, the vessel 160 being secured
to the partition 43. The overflow pipe 155 is held in position
within the water tank 40 by a pair of nuts 156 which are threaded
thereon and are disposed on opposite sides of the bottom wall
41.
The float-operated magnetically controlled valve means 140 of the
present invention is best illustrated in FIGS. 5 to 8 and includes
a vessel 160 comprising a generally cylindrical sidewall 161 and a
bottom wall 162. The sidewall 161 is provided with a vertically
extending pocket 163 integrally formed therein, (FIG. 5), the
pocket 163 receiving the lower end of the overflow pipe 155 as
illustrated by the dashed lines in FIG. 6. The pocket 163 is formed
in the sidewall 161 in a manner such that a vertically extending
passage 164 is provided between the pocket and the interior of the
vessel 160, the passage 164 permitting water to flow from the
overflow pipe and the pocket into the vessel proper.
The bottom wall 162 of the vessel is provided with a first upturned
portion 165 which cooperates with a separate valve casing 180 to
provide a chamber 166 therebetween. The bottom wall 162 is further
provided with a second upturned portion 167 in the form of a
cylinder, the internal surface thereof defining a vertical guide
passage for a plunger 190 disposed therein. The upturned portion
167 defining the guide passage terminates in an upper stop member
168 which limits upward movement of the plunger 190 therein. As
shown in FIG. 5, an outwardly extending tab 169 is provided on the
vessel side wall 161 whereby the vessel 160 is secured to the
partition 43 of the beverage brewer.
A float 170 is disposed within the vessel 160 and includes a
generally cylindrical sidewall 171, a top wall 172 and a bottom
wall 173. The diameter of the float 170 is only slightly less than
the inner diameter of the vessel 160, whereby the side wall 161 of
the vessel serves as a guide surface for the float. The bottom wall
173 of the float is provided with an upturned portion 174 within
which is disposed a permanent magnet 175, the magnet being heat
staked to the float as at 176. The float normally assumes the
position illustrated in FIGS. 6 and 7 wherein the magnet 175 abuts
the stop position 168 of the vessel, the float being movable away
from the stop member upon the introduction of water into the
vessel.
As previously noted, a valve casing 180 is secured to the bottom
wall 162 of the vessel, the casing being held in position by a
plurality of screws 181 which are threaded into appropriately
provided thickened portions of the bottom wall 162 of the vessel.
The casing 180 is provided with a threaded inlet passage 182 which
is adapted to be connected by an appropriate fitting to the conduit
136, and a threaded outlet passage 183 which is adapted to be
connected to the conduit 141 which leads to the flow restrictor
145. A centrally located ported valve seat 184 is provided in the
casing between the inlet and outlet passages 182 and 183
respectively.
As previously noted, the valve casing 180 and the first upturned
portion 165 of the bottom wall of the vessel 160 cooperate to
define a chamber 166 therebetween. Extending across the chamber is
a flexible diaphragm 185 of rubber or the like which is engageable
with the valve seat 164 for effecting a closed valve condition. The
diaphragm 185 includes a main body portion 186 for engagement with
the valve seat 184 and is provided with a relatively flexible
annular portion 187 which terminates in a peripheral bead whereby
the diaphragm is mounted between the vessel bottom wall and the
valve casing in a manner which provides a fluid tight connection
therebetween. The diaphragm 185 divides the chamber 166 into upper
and lower compartments 166U and 166L, respectively.
The diaphragm 185 has a centrally located aperture 188 therein and
a pair of side apertures 189 disposed along the flexible annular
portion thereof, the central aperture 188 being located over the
valve seat 184 and being substantially larger than the apertures
189 which are exposed to the inlet passage 182 at all times.
As previously noted, a plunger 190 is disposed within the guide
surface defined by the wall portion 167 of the vessel, the plunger
190 having a pointed tip at 191 which is engageable at the lower
end of movement thereof with the diaphragm 185 to close off or seal
the central or discharge aperture 188 therein, as illustrated in
FIG. 8.
The plunger 190 is formed of magnetic stainless steel and in the
absence of water within the vessel 160, so that the float 170 is in
the position illustrated in FIG. 6, the magnetic field of
attraction between the magnet 175 and the magnetic plunger 190 is
sufficient to maintain the plunger 190 in an "open" position of
engagement with the stop portion 168.
In operation, when the electrically operated valve 135 is opened to
permit water to flow therethrough, the water will flow through the
conduit 136 into the inlet passage 182 of the valve 140. The water
will then flow through the side apertures 189 in the diaphragm 185
and out the central or discharge aperture 188 thereof. Because the
discharge aperture 188 is substantially larger than the side
apertures 189, the water passing through the side apertures into
the upper compartment 166U flows out of the central or discharge
aperture 168 as fast as it enters so as to provide a lower pressure
in the upper compartment. The inlet pressure on the lower side of
the diaphragm 185 thereby is able to raise the diaphragm 185 off of
the ported seat 184 to the position illustrated in FIG. 7, whereby
the major portion of the water flow is directed beneath the
diaphragm 185 and directly out of the outlet passage 183 and
through the rest of the water inlet system heretofore
described.
In the event of a malfunction which results in an incomplete
closing of the electrically controlled valve 135, or a malfunction
in the float mechanism 70, the water within the tank will rise
until it exceeds the height of the overflow pipe 155, whereupon
excess water will flow through the pipe 155 into the pocket 163 of
the vessel 160 and through the passage 164 between the pocket and
the vessel side wall so as to cause the float 170 to rise therein.
As the water continues to enter and the float continues to rise,
the magnet 175 moves away from the plunger 190 which is limited in
upward movement by the stop portion 163 of the bottom wall. The
plunger 190 will remain in position until the magnetic field of
attraction between it and the magnet 175 is weakened to a point
where the magnet 175 can no longer hold the plunger 190 in its
upper or "open" position. When this occurs, the plunger 190 drops
immediately into the lowermost position thereof as indicated in
FIG. 8, thereby closing the discharge passage 196 of the
diaphragm.
Upon the closing of the central or discharge aperture 198 by
engagement of the plunger 190 therewith as described, the inlet
water passing through the side apertures 189 immediately builds up
substantial pressure within the upper compartment 166U sufficient
to exert a differential downward force upon the diaphragm 185 so as
to cause an immediate snap action closing of the main body portion
of the diaphragm into watertight engagement with the valve seat
184, thereby positively to terminate the flow of water out of the
outlet passage 183 and through the various components into the
water tank 40. It will be appreciated that even though the inlet
flow of water to the machine is terminated the plunger 190 remains
in a closed position until such time as the pressure caused by the
incoming water through inlet passage 192 is relieved.
When the cause of the malfunction has been terminated, the water
within the vessel 160 is removed via a drain opening 192 in the
bottom wall 162 thereof, an appropriate threaded plug (not shown)
being provided to seal the drain opening during normal operation.
When excess water drains out of the vessel, the float 170 drops to
the position illustrated in FIG. 6, wherein the magnet 175 rests
against the stop portion 163 of the bottom wall. When the back
pressure in the inlet passage 182 is relieved, the magnetic field
between the magnet 175 and the magnetic plunger 190 causes the
plunger to rise to the open position illustrated in FIG. 6.
In a typical embodiment, the vessel 160 is formed of nylon such as
Zytel 31 and has an inner diameter of approximately 1 29/32 inches
and an overall length of 4 inches; the stop portion 168 of the
bottom wall being disposed approximately 0.70 inch from the bottom
surface of the bottom wall; the first upturned portion being
disposed approximately 0.265 inch from the lower surface of the
bottom wall; the inner diameter of the second upturned portion 167
defining the guide surface being approximately 0.437 inch, the
diameter of the first upturned portion being approximately 0.825
inch. The float is approximately 1 27/32 inches in diameter and is
approximately 15/8 inches in height. The magnet 175 is about 0.750
inch in diameter and 0.375 inch in height, the magnet being formed
of a material such Indox I. The plunger 190 is approximately 0.468
inch in length, from the upper end to the bottom of the tip 191
thereof, the tip 191 being approximately 0.093 inch in length. The
plunger is formed of stainless steel type 430F which is magnetized
after machining. The valve casing 180 and diaphragm 185 are of the
type included in the valve sold by the Dole Valve Company as its
Model S-30 valve.
The upper end of the overflow pipe 155 is disposed about 8 21/32
inches from the bottom wall of the tank, the upper end of the pipe
being disposed about three-sixteenths inch above the uppermost
adjustable limit of movement of the float 71, in which case the
tank can receive approximately 6 ozs. of water in excess of the
maximum predetermined amount which the float will normally admit
before causing the valve 135 to close. Using a vessel and float
having the dimensions given, the vessel will receive approximately
2 1/2 ounces of overflow water before the float is raised
sufficiently high (about one-fourth inch) to cause the plunger 190
to drop and terminate flow of water through the valve 140.
It will be appreciated from the foregoing that the valve 140 will
operate to the closed position thereof upon the introduction into
the water tank 40 of a quantity of water is excess of the
predetermined quantity admitted for brewing purposes. Furthermore,
the valve 140 is simple in both operation and construction,
including a minimum of moving parts, namely the float 170,
diaphragm 185 and plunger 190. Moreover, by forming the bottom wall
of the vessel in the manner disclosed, the vessel may be combined
with component valve parts currently available, the bottom wall of
the vessel providing one wall of the chamber for the diaphragm and
also the guide surface for the plunger, while permitting direct
operation of the permanent magnet carried by the float on the
plunger.
Referring now to FIG. 9, there is shown a typical electrical
circuit for the beverage brewing machine 10, the input to the
electrical circuit of FIG. 9 being on a pair of line conductors
designated as A and B and connected through suitable switches and
fuses (not shown) to a suitable 115 volt 60 cycle AC supply.
As illustrated, a branch conductor 200 is connected to the line
conductor A, the conductor 200 being connected to a first terminal
of the float actuated reed switch 77, the second terminal of the
switch 77 being connected through a conductor 201 to one terminal
of a first switch 202 of a double pole, double throw relay,
designated generally as 203. The switch 202 is normally disposed in
the position shown in FIG. 8 wherein it contacts a dead terminal
204 in the relay 203. When the relay is energized as hereinafter
described the switch 202 is caused to move to a second position
thereof wherein it engages a contact 205 of the relay 203, the
contact 205 being connected through a conductor 206, to a first
terminal of the relay coil 207, the second terminal of the relay
coil 207 being connected to the line conductor B, thereby to
provide a holding circuit through the relay.
The branch conductor 200 is also connected to one terminal of the
manually operated switch 30, the switch 30 having two operative
positions. The switch 30 is normally in the position shown in FIG.
8 where it engages contact 208 thereof, contact 208 being connected
by the conductor 209 to one terminal of a second switch 210 in the
relay 203.
When the switch 30 is depressed by the operator it momentarily
engages the second contact 211 thereof which is connected through
conductor 206 to the coil 207 as previously described, whereby
depression of the switch 30 causes the relay 203 to be energized,
causing switch 202 therein to close and provide the holding circuit
for the relay.
The second switch 210 in the relay is normally in the position
shown in FIG. 8, wherein it engages a dead contact 212 in the
relay; energization of the relay 203 causing the switch 210 to move
to a second position thereof wherein it engages contact 213 in the
relay, contact 213 in the relay being connected by a conductor 214
to the coil 215 of the solenoid operated water inlet valve 135, the
second terminal of the coil 215 being connected to the line
conductor B.
When the switch 30 is closed to engage contact 211, a completed
circuit is provided through the line conductor A, conductor 200,
switch 30, conductor 206, relay coil 207 and line conductor B. At
this time the relay 203 is energized and causes switches 203 and
210 to engage contacts 205 and 213 respectively. When the relay 202
is energized a holding circuit therefor is completed through
conductor 200, float operated switch 77, conductor 201, switch 202,
contact 205, conductor 206, relay coil 207 and line conductor
B.
The switch 30 is a momentary type switch which is normally spring
biased so that after it completes the circuit through conductor 200
is returns to the position shown in FIG. 8. At this time a circuit
is also completed through conductor 200, switch 30, conductor 209,
switch 211, contact 215, conductor 214 and the coil for the valve
135, whereby cold water is allowed to flow through the water inlet
system as previously described.
When the hot water in the water tank reaches the maximum
predetermined level therein, indicated as 95, the float actuated
switch 77 opens to deenergize relay 203, thereby causing the switch
210 to engage the dead contact 212 in the relay and thus deenergize
the coil 15 to prevent further introduction of cold water to the
hot water tank.
Also as illustrated, the conductor A is connected to one terminal
of a tank thermostat switch 67, the other terminal of the
thermostat switch 67 being connected through a conductor 221 to one
terminal of the heating coil 60 for the water tank 40. The second
terminal of the coil 60 is connected to the conductor B. The
operation of the heating unit 60 under control of the thermostat
switch 67 is fairly conventional, the switch 67 being closed to
provide a circuit through the heating coil 60 when the temperature
of the water within the tank drops below a preselected value.
As previously noted, the upper heating unit 26 is controlled by
both a thermostatically controlled switch 27 and a manual switch
28, one terminal of the switch 27 being connected to the main
conductor A and the other terminal thereof being connected to a
conductor 222 which in turn is connected to one terminal of the
manually controlled switch 28. The other terminal of the manual
switch 28 is connected to a conductor 223, one terminal of the
pilot light 29 being connected to one branch of the conductor 223
and the upper heating unit 26 also having one terminal connected to
the conductor 223. The other terminal of the pilot light 29 is
connected to the line conductor B; similarly, the other terminal of
the heating element 26 is also connected to the line conductor
B.
The upper heating unit 26 is used to maintain a previously brewed
beaker of coffee at a predetermined temperature. In operation, the
beaker containing the brewed coffee is placed on the upper heating
unit 26, and the manual control switch 26 is closed. If the brewed
beverage within the beaker is already at the predetermined
temperature, the thermostatically controlled switch 27 will remain
open so as to open the circuit through the heating element 26, the
switch 27 remaining open so long as the beverage is at the
predetermined temperature. As the beverage within the beaker cools
below the predetermined temperature, the thermostatically
controlled switch 27 closes to complete the circuit through the
line conductor A, the switch 27, the conductor 222, the switch 29,
the conductor 223, the upper heating unit 26, the pilot light 29
and the line conductor B, thereby to energize the heating unit 26
so as to heat the beverage within the beaker. When the temperature
of the beverage in the beaker reaches the predetermined value, the
thermostatically controlled switch 27 opens to break the circuit
and deenergize the heater 26. The preferred temperature at which
the beverage should be maintained by the heating unit 26 is
175.degree..times.5.degree. F.
One terminal of the switch 15 for the lower heater 14 is also
connected to the main conductor A, a second terminal of the switch
15 being connected through a conductor 224 to one terminal of a
light 225, the second terminal of the light 225 being connected to
the line conductor B. A third terminal of the switch 15 is
connected through a conductor 226 to one terminal of the heating
element 14, the other terminal of the heating element 14 being
connected to the main conductor B, whereby closing of the switch 15
causes both the heating element 14 and the light 225 to be
energized.
In operation, it will be assumed that the water tank 40 is
initially filled with water to the level indicated at 90 in FIG. 2
and that the tank heater 60 under the control of the tank
thermostat 65 is energized to bring the water within the tank to a
predetermined temperature, the thermostat switch 67 being closed
and opened in such manner as to maintain the temperature of the
water in the water tank 40 in the neighborhood of
191.degree..+-.4.degree. F.
When it is desired to cause coffee extract to flow into the beaker
39 the latter is positioned on the heating element 14 and the
control switch 15 is closed to energize the heating element 14 and
also to cause the indicating light 225 for the switch to be
energized. A supply of fresh ground coffee is placed in a cup of
filter paper within the brew basket 37. The basket 37 is then
inserted below the discharge head 35.
The manual cycle control switch 30 is then momentarily depressed
causing the relay 203 to be energized in the manner heretofore
described, energization of the relay causing the switch 210 therein
to complete a circuit through the coil 215 of the inlet valve 135
and thereby causing cold water to flow through the water inlet
valve 135, the magnetically controlled valve 140, the flow
restrictor 145 and through the delivery conduit 150 into the upper
end of the tube 50. The cold water flows directly through the tube
50 into the lower portion of the water tank 40 thereby causing hot
water contained therein to be upwardly displaced in the tank
40.
Concurrently therewith, the flow restrictor 145 develops a back
pressure which causes some of the entering cold water to flow
through the conduit 115 to the inlet passage 111 of the discharge
valve 100, the inlet water pressure causing the plunger 120 in the
valve 100 to move to the closed position thereof as illustrated in
FIG. 4. When the valve 100 is in the closed position thereof hot
water is prevented from discharging from the water tank 40 through
the discharge block 80.
As the hot water continues to rise in the water tank 40, the float
71 will eventually rise therewith until such time as the magnet 75
carried by the arm 74 moves sufficiently far away from the reed
switch 77 to permit the reed switch to open, thereby deenergizing
the relay 203 and the coil 215 for the water inlet valve 135.
When the water inlet valve 135 is deenergized and the inlet flow of
water terminated, there is no longer back pressure developed by the
flow restrictor 145, whereby the force of the spring 129 and the
head pressure of the hot water in the inlet passage 102 are
sufficient to cause the plunger 120 to move to the discharge
position thereof as illustrated in FIG. 3, at which time hot water
can flow through the discharge block 80, the discharge line 85, the
discharge valve 100 and the discharge head 35 to be sprayed over
the ground coffee in the brew basket 37, until all of the hot water
in the upper portion of the water tank flows out of the discharge
water line and the water level in the water tank reaches the
standby position 90 therein, at which time the brewing cycle is
completed.
Using a tank having a "fill" capacity of approximately 60 ounces
and using a flow restrictor which introduces water to the tank at
the rate of approximately 1 gallon per minute, it will take
approximately 30 seconds to fill the tank with the predetermined
quantity of cold water. It will then take approximately 2 minutes
to discharge a like quantity of hot water from the tank through the
discharge block, the discharge valve and the discharge head, and
approximately another 11/4 minutes for the hot water to completely
filter through the coffee grounds in the brew basket for discharge
into the beaker, whereby the total elapsed time for a brewing cycle
is approximately 33/4 minutes to 4 minutes.
It will be apparent from the foregoing that the discharge valve 100
and the float actuated switch mechanism 70 cooperate with the water
inlet valve 135 in a unique manner, the discharge valve being
operable in response to operation of the water inlet valve 135 to
prevent discharge of hot water from the tank while the valve 135 is
open to introduce cold water into the tank, whereupon upward
displacement of hot water in the tank to a predetermined level
therein is effective to close the inlet water valve.
Because the volumetric capacity of the tank between the lower end
of the discharge block 80 and the actuating position of the float
is substantially constant, only a predetermined quantity of cold
water can be introduced to the machine during each cycle, and,
because of the location of the discharge block in the tank
sidewall, only that predetermined quantity of cold water which is
admitted to the tank will be discharged as hot water therefrom. By
providing predetermined amounts of ground coffee 38 on the
disposable filter cup in the brew basket 37 and by maintaining the
temperature of the water in the water tank 40 at a predetermined
value, it is possible to make the coffee extract under identical
controlled conditions for each brewing cycle.
Furthermore, the overflow control provided by the overflow pipe 155
and the float-operated magnetically controlled valve 140 insure
that in the event of a malfunction in the machine which results in
the introduction of a quantity of water in excess of the
predetermined quantity, the flow of input water to the machine will
positively terminate.
While there has been described what is at present considered to be
the preferred embodiment of the invention, it will be understood
that various modifications may be made therein, and it is intended
to cover in the appended claims all such modifications as fall
within the true spirit and scope of the invention.
* * * * *