U.S. patent application number 10/078183 was filed with the patent office on 2002-06-27 for automatic popcorn popper with thermal controller.
This patent application is currently assigned to Gold Medal Products Co.. Invention is credited to Hodgson, Lee Kindly, Weiss, Ronald R..
Application Number | 20020078832 10/078183 |
Document ID | / |
Family ID | 27407682 |
Filed Date | 2002-06-27 |
United States Patent
Application |
20020078832 |
Kind Code |
A1 |
Weiss, Ronald R. ; et
al. |
June 27, 2002 |
AUTOMATIC POPCORN POPPER WITH THERMAL CONTROLLER
Abstract
Apparatus and methods for popping popcorn comprise a heated
kettle which is controlled and monitored according to the
temperature of the kettle. The kettle is initially heated to a
start cook temperature and a buzzer and light alert an operator to
add uncooked popcorn and oil to the kettle which lowers the
temperature of the kettle below a predetermined start temperature
and initiates a cooking cycle. An oil pump system is enabled at the
initiation of the cooking cycle for adding oil to the kettle. As
the popcorn and oil cook, the kettle temperature increases and
passes through a predetermined dump temperature and the kettle
automatically tilts and dumps the cooked popcorn. After the dump,
the kettle temperature increases to the start cook temperature
again and the buzzer and light are activated to alert the operator
to add another batch of ingredients for consecutive batches of
popcorn.
Inventors: |
Weiss, Ronald R.; (Okeana,
OH) ; Hodgson, Lee Kindly; (Cincinnati, OH) |
Correspondence
Address: |
WOOD, HERRON & EVANS, L.L.P.
2700 Carew Tower
441 Vine St.
Cincinnati
OH
45202
US
|
Assignee: |
Gold Medal Products Co.
10700 Medallion Drive
Cincinnati
OH
45241-4807
|
Family ID: |
27407682 |
Appl. No.: |
10/078183 |
Filed: |
February 19, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10078183 |
Feb 19, 2002 |
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09589944 |
Jun 7, 2000 |
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6354191 |
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09589944 |
Jun 7, 2000 |
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09416856 |
Oct 12, 1999 |
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6092458 |
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09416856 |
Oct 12, 1999 |
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09212667 |
Dec 16, 1998 |
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6000318 |
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09212667 |
Dec 16, 1998 |
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08910756 |
Aug 13, 1997 |
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5871792 |
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08910756 |
Aug 13, 1997 |
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08633580 |
Apr 17, 1996 |
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5743172 |
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08633580 |
Apr 17, 1996 |
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08345303 |
Nov 28, 1994 |
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5694830 |
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Current U.S.
Class: |
99/323.5 ;
99/323.7 |
Current CPC
Class: |
G07F 17/0085 20130101;
G07F 17/0078 20130101; A23L 7/187 20160801 |
Class at
Publication: |
99/323.5 ;
99/323.7 |
International
Class: |
A23L 001/18 |
Claims
What is claimed is:
1. Apparatus for popping corn comprising: a kettle; a kettle
operating system for heating and operating the kettle and popping
popcorn placed therein; a control system responsive to a kettle
temperature condition and operably coupled to the kettle operating
system to control kettle operation in response to said kettle
temperature condition.
2. Apparatus as in claim 1 wherein the operating system is operable
to tilt the kettle, the control system being further responsive to
said kettle temperature condition to automatically tilt the kettle
and dump the popcorn when it is popped.
3. Apparatus as in claim 2 wherein the kettle operating system
includes a dump motor operably coupled to tilt the kettle and dump
popped popcorn from the kettle, the control system operating the
dump motor to automatically dump the popcorn when it is popped.
4. Apparatus as in claim 2 wherein the control system causes the
popcorn to dump when the kettle temperature exceeds a predetermined
dump temperature.
5. Apparatus as in claim 4 wherein the kettle operating system
further includes a temperature sensor coupled to the kettle for
providing a kettle temperature signal indicative of the kettle
temperature, the control system operably coupled to receive the
kettle temperature signal for dumping the popcorn when the kettle
temperature exceeds said predetermined dump temperature.
6. Apparatus as in claim 1 wherein the control system is further
responsive to provide a humanly perceptible indication when the
kettle temperature is heated to reach an equilibrium start cook
temperature to alert the operator that the kettle is ready to
cook.
7. Apparatus as in claim 6 wherein the kettle operating system
includes an indicator and a heater operably coupled to heat the
kettle to said start cook temperature, the control system providing
said indication through the indicator when the heater heats the
kettle to said start cook temperature to alert the operator to load
the kettle with uncooked popcorn.
8. Apparatus as in claim 7 wherein said indicator includes a
speaker element for providing an audible indication to alert the
operator that the kettle is ready to cook.
9. Apparatus as in claim 7 wherein said indicator includes a
flashing light for providing a visual indication to alert the
operator that the kettle is ready to cook.
10. Apparatus as in claim 1 wherein the kettle operating system
includes a temperature sensor coupled to the kettle for providing a
kettle temperature signal indicative of the kettle temperature, the
control system operably coupled for receiving the kettle
temperature signal and operable for initiating a popcorn cooking
cycle when the kettle temperature decreases below a predetermined
start temperature.
11. Apparatus as in claim 1 wherein the kettle is tiltable and the
kettle operating system includes a temperature sensor coupled to
the kettle for providing a kettle temperature signal indicative of
the kettle temperature and a dump motor operably coupled to tilt
the kettle, the control system operable to receive the kettle
temperature and initiate a popcorn cooking cycle when uncooked
popcorn is added to the kettle and the kettle temperature decreases
below a predetermined dump temperature and further operable to
actuate the dump motor and dump cooked popcorn from the kettle when
the kettle temperature subsequently rises back up to and exceeds
said predetermined dump temperature.
12. Apparatus as in claim 1 further comprising an oil delivery
system including a pump system and a reservoir of oil, the pump
system operable to deliver oil from the reservoir to the kettle to
pop popcorn therein, the control system further operable to disable
the pump system in response to said kettle temperature
condition.
13. Apparatus as in claim 2 further comprising a stir blade
operably mounted to turn inside said kettle, the stir blade being
operable to rotating to a position when the kettle is tilted to
allow generally unhindered dumping of the popcorn.
14. Apparatus as in claim 13 wherein said stir blade is weighted on
one side thereof for rotating to said position when the kettle is
tilted.
15. Apparatus for popping popcorn comprising: a tiltable kettle
including a heater to heat the kettle during a cooking cycle for
popping uncooked popcorn placed therein; a sensor operably coupled
to sense the temperature of the heated kettle and generate a
temperature signal indicative of the kettle temperature; a dump
motor operably coupled to selectively tilt the kettle from an
upright position and dump the popcorn; a control system operable to
receive said sensed kettle temperature signal from the sensor and
coupled to the dump motor to automatically tilt the kettle from an
upright position and dump the popcorn when the kettle temperature
exceeds a predetermined dump temperature upon completion of the
cooking cycle.
16. Apparatus as in claim 15 wherein the kettle temperature
decreases to a minimum temperature below said dump temperature when
uncooked popcorn is placed in the kettle, the control system being
responsive to the minimum temperature signal and dumping the
popcorn only when a dump temperature signal is preceded in time by
the kettle minimum temperature signal.
17. Apparatus as in claim 15 wherein the control system is further
operable to disable the dump motor and prevent the dumping of
popcorn when the kettle temperature is below said dump
temperature.
18. Apparatus as in claim 15 wherein said dump temperature is in
the range of 425.degree. F. to 500.degree. F.
19. Apparatus as in claim 15 wherein the heater is operable to
maintain the kettle at an equilibrium start temperature above said
dump temperature when no popcorn is being cooked, the kettle
temperature decreasing below a predetermined low temperature when
uncooked popcorn is added to the kettle, the control system
responsive to a decrease in kettle temperature from said start
temperature to a temperature below said predetermined low
temperature and initiating a cooking cycle thereupon.
20. Apparatus as in claim 19 wherein said equilibrium start
temperature is in the range of 500.degree. F. to 550.degree. F.
21. Apparatus as in claim 19 wherein the kettle temperature
subsequently increases as the popcorn in the kettle is cooked
during a cooking cycle and the control system is responsive to such
an increase, the apparatus further comprising an indicator coupled
to the controller and operable to provide a humanly perceptible
indication when the kettle has risen back up to said equilibrium
start temperature after the popcorn has been cooked and dumped such
that an operator is alerted to add another batch of uncooked
popcorn to the kettle and initiate another cooking cycle.
22. Apparatus as in claim 15 wherein the control system is operable
to move the tilted kettle back toward an upright position and then
to subsequently tilt the kettle to dump the popcorn again.
23. Apparatus as in claim 21 wherein said indicator provides an
audible indication to the operator.
24. Apparatus as in claim 21 wherein said indicator provides a
visual indication to the operator.
25. Apparatus as in claim 15 further comprising an oil pump system
for pumping cooking oil to the kettle at the initiation of a
cooking cycle, the controller system further responsive to the
sensed kettle temperature signal and operably coupled to disable
the oil pump system in response to the kettle temperature.
26. Apparatus as in claim 25 further comprising a kettle position
sensor to sense when the kettle is in an upright position, the
control system coupled to the position sensor and operable for
disabling the oil pump system when the kettle is not in an upright
position.
27. Apparatus as in claim 25 wherein the control system is operable
to enable the oil pump system when the kettle temperature has
exceeded the dump temperature.
28. Apparatus for popping popcorn comprising: a tiltable kettle
including a heater to heat the kettle for popping uncooked popcorn
placed therein, the heater maintaining the kettle at an equilibrium
start temperature when no popcorn is being popped; a sensor
operably coupled to sense the temperature of the heated kettle and
to sense a fall in kettle temperature from said start temperature
which occurs when uncooked popcorn is placed in the kettle; a
control system operable for receiving said sensed kettle
temperature from the sensor and responsive to the kettle
temperature for initiating a cooking cycle when the kettle
temperature falls below a predetermined temperature; the control
system further responsive to the kettle temperature while popcorn
is being popped during the cooking cycle and the sensor sensing the
rise in kettle temperature which occurs as the popcorn is popped,
the control system operable to end the cooking cycle and
automatically produce tilting of the kettle and dumping of the
popped popcorn when the kettle temperature subsequently rises above
said predetermined temperature.
29. Apparatus as in claim 28 wherein the control system is further
operable to cause a humanly perceptible indication to be generated
by an indicator when the kettle temperature rises back to a start
temperature above said predetermined temperature after the popcorn
has been dumped such that an operator is alerted to add another
batch of uncooked popcorn to the kettle and initiate another
cooking cycle.
30. Apparatus as in claim 28 wherein the control system is further
operable for heating the kettle back up to the start temperature
after the dumping of the popcorn so that the kettle is ready to
receive and cook another batch of popcorn.
31. Apparatus for popping popcorn comprising: a kettle including a
heater to heat the kettle for popping uncooked popcorn placed
therein; a sensor operably coupled to sense the temperature of the
heated kettle and generate a temperature signal indicative of the
kettle temperature; an oil pump system for pumping cooking oil to
the kettle for popping the popcorn; a control system response to
said temperature signal and operably coupled to the oil pump system
for enabling and disabling the oil pump system in response to the
kettle temperature.
32. Apparatus as in claim 31 wherein the control system is operable
for disabling the oil pump system when the kettle temperature falls
to a level below a predetermined minimum temperature.
33. Apparatus as in claim 31 wherein the heater is switchable
between an ON position and an OFF position, the control system
being operable for disabling the oil pump system when said heater
is switched to an OFF position.
34. Apparatus as in claim 31 wherein the kettle is tiltable between
an upright position for popping popcorn and a dump position for
dumping the popped popcorn, the apparatus further comprising a
position indicator for determining the position of the tiltable
kettle, the control system operable for disabling the oil pump
system when the position indicator indicates that the kettle is not
in an upright position.
35. Apparatus as in claim 31 wherein the heater is operable to heat
the kettle to a start temperature for popping the popcorn, the
control system operable for enabling the oil pump system to
automatically pump oil to the kettle when the kettle temperature is
proximate said start temperature.
36. Apparatus as in claim 31 wherein the control system is further
operable for automatically pumping oil to the kettle in response to
the sensed kettle temperature.
37. Apparatus as in claim 31 wherein the control system is further
operable for initiating a cooking cycle when the kettle temperature
drops below a predetermined minimum point after uncooked popcorn is
placed therein, the control system enabling the oil pump system for
pumping oil to the kettle for the cooking cycle and subsequently
disabling the oil pump system until a subsequent cooking cycle
begins whereby to generally prevent excess oil in the kettle in a
single cooking cycle.
38. A method for popping popcorn comprising: placing uncooked
popcorn in a kettle; heating the kettle for cooking and popping the
uncooked popcorn placed therein and dumping the kettle for
dispensing the popped popcorn; monitoring a kettle temperature
condition and selectively heating and dumping the kettle in
response to said monitored kettle temperature condition.
39. The method of claim 38 further comprising providing a humanly
perceptible indication when the kettle is heated to a predetermined
start temperature to alert an operator to load the kettle with
unpopped popcorn.
40. The method of claim 38 wherein the kettle is tiltable and
further comprising tilting the kettle in response to said
temperature condition to dump the popcorn from the kettle after it
has been popped.
41. The method of claim 40 further comprising sensing a temperature
drop in the kettle indicating loading of the kettle with uncooked
popcorn after the kettle is heated and sensing a subsequent
temperature rise in the kettle indicating that the popcorn is being
popped; tilting the kettle and dumping the popcorn when the kettle
temperature subsequently rises and exceeds a predetermined dump
temperature indicating that a portion of the popcorn is popped.
42. The method of claim 41 further comprising initiating a cooking
cycle when the kettle temperature drops when the uncooked popcorn
is added and decreases below a predetermined cycle temperature.
43. The method of claim 42 wherein said cycle temperature is
approximately equal to said dump temperature.
44. The method of claim 38 further comprising delivering an amount
of cooking oil to the kettle in response to said monitored kettle
temperature condition.
45. The method of claim 44 further comprising preventing the
delivery of any additional oil to the kettle after said amount is
delivered until after the kettle is dumped.
46. The method of claim 38 further comprising pumping oil to the
kettle with an oil pump system and disabling the oil pump system in
response to said monitored kettle temperature condition.
47. The method of claim 38 wherein the kettle is movable between an
upright position for cooking the popcorn and a dump position for
dumping the popped popcorn, the method further comprising pumping
oil to the kettle with an oil pump system and disabling the oil
pump system when the kettle is not in an upright position.
48. The method of claim 44 further comprising automatically pumping
oil to the kettle from an oil pump system in response to said
monitored kettle temperature condition.
49. A method for popping popcorn comprising: heating a kettle for
cooking and popping uncooked popcorn placed therein; monitoring the
temperature of the heated kettle; providing a humanly perceptible
indication when the kettle has been heated up to a predetermined
start temperature to alert an operator to load the kettle with
uncooked popcorn.
50. The method of claim 49 wherein said predetermined start cook
temperature is in the range of approximately 500.degree. F. to
550.degree. F.
51. The method of claim 49 further comprising sensing a drop in
kettle temperature indicating loading of the kettle with uncooked
popcorn to be cooked and popped; and, initiating a cooking cycle
when the monitored kettle temperature decreases below a
predetermined cycle temperature.
52. The method of claim 51 wherein said predetermined cycle
temperature is in the range of approximately 425.degree. F. to
500.degree. F.
53. The method of claim 49 further comprising providing an audible
indication in response to said kettle being heated.
54. The method of claim 49 further comprising providing a visual
indication in response to said kettle being heated.
55. The method of claim 49 further comprising: sensing a drop in
kettle temperature indicating loading of the kettle with uncooked
popcorn to be cooked and popped and sensing a subsequent rise in
the kettle temperature indicating that the popcorn is being popped;
tilting the kettle and dumping the popcorn when a portion of the
popcorn has been popped and the kettle temperature subsequently
rises and exceeds a predetermined dump temperature.
56. The method of claim 55 wherein said predetermined dump
temperature is in the range of approximately 425.degree. F. to
500.degree. F.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of application
Ser. No. 08/345,303 entitled, "Automated Corn Popper" and filed
Nov. 28, 1994; which application is incorporated herein by
reference in its entirety.
FIELD OF THE INVENTION
[0002] This invention relates generally to popcorn poppers and more
specifically to an automatic popcorn popper which produces popcorn
in consecutive batches while reducing the amount of attention
required from an operator. This invention also relates to an
improved method for popping popcorn.
BACKGROUND OF THE INVENTION
[0003] Popcorn is mass-produced for sale at movies and other events
in commercial popcorn poppers which include an enclosed,
transparent cabinet containing a tiltable kettle suspended above a
catch area or platform. The kettle is heated and uncooked popcorn
kernels are placed therein to be cooked and popped. Once the
kernels are popped, the kettle is manually tilted and the popcorn
spills onto the platform to be scooped up, packaged and sold to
customers.
[0004] Conventionally, commercial popcorn poppers have been
manually operated and have required an operator's constant
attention for cooking the kernels and subsequently dumping the
popped popcorn. For example, an operator would load the kettle with
popping oil and unpopped corn kernels and then listen and watch for
the unpopped corn to pop. When the operator decided, somewhat
arbitrarily, that the corn was sufficiently popped, they would then
dump the kettle and spill the popcorn onto the serving platform.
Additional oil and corn would then be added for the next batch.
While such conventional popcorn poppers are generally effective in
mass-producing popcorn; the constant attention they require
prevents the operator from other important tasks, such as selling
the popcorn and other concession products, taking money and
generally servicing customers.
[0005] As may be appreciated, the multiple duties entrusted
concessionaire operators are not conducive to having them
constantly monitor a popcorn popper. If attention is diverted for
an extended length of time, the popcorn is susceptible to being
burned or overcooked. In addition to the waste of burned popcorn,
the aroma of the burned popcorn is not attractive to customers and
may actually discourage purchases. Furthermore, if the operator
inadvertently dumps the burned corn onto the platform, it will
contaminate the usable popcorn which has already been produced and
may render the entire batch inedible and thus unusable. Still
further, the results and mess from burned popcorn is not easy to
clean. The kettle is hot and must be allowed to cool before the
burned popcorn is removed and the kettle placed back in
service.
[0006] Additionally, the arbitrary nature of the dumping process
with conventional poppers makes them subject to messes associated
with premature dumping. For example, if the operator mistakenly
believes that the corn has been completely popped and the oil used
when indeed uncooked corn and oil remains in the kettle, tilting
the kettle will spill oil onto the serving platform and possibly
onto the counter. Such spills ruin and waste popcorn and create a
mess which must be cleaned, adding to the already numerous tasks of
a concessionaire.
[0007] Still further, too much oil may be added for a particular
cooking cycle, and even if the cooking cycle is completed, excess
oil might be left, again resulting in a mess upon dumping of the
batch. For example, one operator may load the uncooked corn and oil
for a batch, and another operator may subsequently and
inadvertently load more oil, believing it had not been added. The
excess oil does not burn off or cook and remains in the kettle. Not
only is a mess created upon dumping, but the excess oil may also
foul the batch of popcorn.
[0008] Another drawback of conventional popcorn poppers is the
inherent delays which will occur between cooked batches of popcorn.
When the popcorn has been cooked and dumped, the operator may begin
serving it to customers without replenishing the supply of corn and
oil and starting the next batch. Therefore, the next batch of
popcorn will not be produced until the operator consciously sets
aside time from his other activities to do so. Such delays
interrupt production rates and introduce inefficiencies into the
operation which reduce popcorn sales.
[0009] It is also desirable to pop popcorn consistently so that it
produces consistent taste from batch to batch. The vagaries of
prior systems leave much to chance in this regard so that batches
of corn are undercooked, burned or the like and at the least are
inconsistent in taste.
[0010] Still another drawback to conventional popping mechanisms is
that they sometimes provide inconsistent or improper heating of the
popcorn so that proper expansion of the kernels upon popping is not
achieved. Particularly, when the heat is too high, the steam from
the kernel is prematurely forced out and the popped kernel is
small. If the temperature is too low, the kernels do not experience
proper hull expansion and brittleness at popping and the popped
kernels are small. As may be appreciated, small popcorn kernels
reduce the yield of popped popcorn per unit of uncooked kernels,
thus reducing the efficiently of the popping apparatus and raising
the cost of the operation.
[0011] As a result, it is one objective of the present invention to
provide improved apparatus and/or methods to pop popcorn
continuously in consecutive batches with minimal attention by an
operator.
[0012] It is another objective to ensure that the popcorn is
consistently and properly cooked in each batch.
[0013] It is a further objective of the present invention to reduce
the burning of popcorn sometimes associated with conventional
machines and operator inattention.
[0014] It is also an objective of the invention to always provide
the proper amount of cooking oil and thus reduce the messes
associated with such burned popcorn or spilled, uncooked oil and
thereby allow an operator to focus upon customers and popcorn
sales.
[0015] It is a still further objective of the invention to reduce
the delays between fresh batches of popcorn attributable to lack of
attention by the operator.
[0016] It is a still further objective of the invention to increase
the production rate of consecutive batches of fresh popcorn to
thereby increase the sales from and the profitability of a
commercial popcorn popper.
[0017] Still further, it is an objective to provide the proper and
consistent temperature to the kernels as they cook to ensure proper
popping conditions and to maximize the popcorn yield per unit of
kernels.
SUMMARY OF THE INVENTION
[0018] Addressing these objectives, the present invention comprises
a popcorn popper which may be left unattended to automatically cook
and dump popcorn once it has been loaded with the proper
ingredients, such as uncooked popcorn. The proper, premeasured
amount of oil pump is then added by the oil pump system upon the
initiation of a cooking cycle so that the operator does not have to
worry about measuring oil or excess oil in the kettle. The popcorn
popper of the invention is responsive to kettle temperature
conditions to automatically cook popcorn kernels, subsequently dump
the finished popcorn, and then alert the operator to load more
ingredients such as oil and uncooked kernels, and start the next
batch. In that way, all of the batches of fresh popcorn are
properly cooked at regular periods with the proper amount of oil
and heat, and the operator is left to attend to other tasks.
[0019] According to the invention, popcorn is consistently cooked
by introducing an amount of popcorn and oil to a cooking system,
comprising a heated kettle, for a duration sufficient to heat the
corn and oil a predetermined amount, and then automatically dumping
popped popcorn after a sufficient amount of heat energy has been
absorbed by the corn and the oil to pop the corn. The application
of heat energy to the corn and oil is not monitored and controlled
by time, but rather by the heat conditions of the cooking system
for each batch. In this regard, a kettle is heated to a start
temperature and cycled about that temperature through a small
temperature range. When unpopped corn and oil are introduced, a
thermocouple on the kettle senses a temperature drop (cycle point)
and a cooking or popping cycle begins. The corn and oil absorb the
heat energy and are heated in the kettle until the kettle
temperature climbs back to a predetermined temperature (dump point)
indicating sufficient heat energy has been applied to the corn and
oil to pop the corn. At that point, the kettle is automatically
dumped.
[0020] Since the controller is temperature, rather then time
responsive, the operator is assured a consistent amount of heat is
always applied to the corn and oil for consistent popping. If the
kettle dump was controlled by time alone, and the environment
changed, such as a cabinet door being open, the cooking cycle might
time out before sufficient heat energy was applied to consistently
cook that batch of corn. Moreover, since the start temperature is
held within a narrow predetermined range, the oil and corn will not
be prematurely burned and the temperature gradients applied thereto
will be more consistent. Also, such a method accommodates at least
some variations in the amount of corn and oil introduced to the
kettle. If too little, the temperature drop will not be as great
and the rise to the predetermined dump temperatures takes a shorter
time, thus sufficient but less heat is introduced so this batch is
consistently popped. In a corresponding manner, larger amounts of
corn and oil will slow the climb of temperature to the dump point
insuring that sufficient heat is imparted to pop the corn
consistently with other batches.
[0021] To further ensure proper cooking by the invention, a
premeasured amount of oil is introduced to the kettle at the
beginning of a cooking cycle. The controller is coupled to an oil
pump system which is operably in fluid communication with the
kettle. Upon the kettle reaching the proper start temperature or
cooking temperature, the oil pump system and an oil pump switch are
enabled. The operator then actuates the oil pump switch to activate
the pump system and deliver a proper, premeasured amount of oil to
the kettle. The oil pump system and switch are disabled by the
controller if the kettle heat is not ON (no cooking cycle) or the
kettle is tilted from an upright position, such as to be cleaned.
Furthermore, in accordance with the principles of the present
invention, the oil pump system will only deliver one load of oil
per cooking cycle to prevent an oil overload or spilling of oil
when the cooked batch of popcorn is dumped. Therefore, the oil pump
switch may be actuated numerous times and only one load of oil will
be delivered per cooking cycle.
[0022] In an alternative embodiment of the invention, the
controller is operable to activate the oil pump system
automatically upon the initiation of a cooking cycle. To that end,
the controller provides an output signal to the oil pump system to
pump a premeasured amount of oil to the kettle at a predetermined
time in the cooking cycle. For example, the oil might be added when
the kettle has risen to a start temperature or might be added after
the popcorn has been added. If the oil pump system has a
mechanically adjusted timer mechanism for pumping a premeasured
amount, an output signal is provided by the controller to activate
the pump and pump oil into the kettle. If the oil pump system
includes a programmable timer mechanism, the controller is operable
to provide additional timer outputs to adjust the amount of time
that the pump will deliver oil when activated. In either case, a
premeasured and proper amount of oil is delivered to the kettle
each cooking cycle. The controller will not activate the pump
system until the kettle is hot and ready to cook and is
upright.
[0023] More specifically, the popper apparatus includes a kettle
which is coupled to a dumping motor and a heater which are
controlled by a controller which monitors the kettle temperature.
The controller includes a temperature sensor, such as a
thermocouple, which is operably connected to the kettle proximate
the heaters. By monitoring the temperature of the kettle, the
controller is operable to dump the kettle at the proper time and to
alert the operator when another batch of uncooked corn kernels
should be added to the kettle. Since the kettle temperature is
constantly monitored, and the dump cycle is automatically
controlled, the burning of popcorn is prevented. Furthermore, an
operator does not have to constantly monitor the procedure to
prevent such burning and can thus turn his attention to other
tasks. The popper begins a cooking or popping cycle when fresh
ingredients are added, and by alerting the operator at the end of
each popping cycle, the popper effectively reduces the delay
between batches to increase its productivity.
[0024] In a preferred embodiment of the invention, a programmable
logic controller (PLC) is coupled to a temperature controller
which, in turn, is coupled to a kettle thermocouple and to kettle
heaters. When the popper is turned ON and the kettle heat is turned
ON, the kettle is heated to an equilibrium start or cooking
temperature of, for example, approximately 525.degree. F. The
thermocouple and temperature controller preferably maintain the
desired 525.degree. F. kettle cooking temperature in a small cycled
range of +/-10.degree. F. When the kettle has reached the
equilibrium start temperature, the PLC activates indicators which
provide visual and audible indications that the kettle is ready to
make popcorn. The oil pump system and pump switch are enabled and
the operator actuates the oil pump switch to load the oil which is
pumped in by the oil pump, and also loads the uncooked popcorn
kernels.
[0025] Alternatively, the oil might be loaded by hand by the
operator. In still another alternative embodiment of the invention,
as discussed above, the PLC provides outputs directly to the oil
pump system to automatically pump oil to the kettle at the
initiation of a cooking cycle. The PLC is operably coupled to the
oil pump system to activate the pump for a predetermined amount of
time to ensure a premeasured amount of oil. A timer determines how
long the pump runs once activated to ensure the proper amount of
oil. The invention may incorporate an oil pump system having a
mechanically adjusted timer, such as a dial timer, or may
incorporate a system having a separate programmable timer. In the
latter case, the PLC is operable to provide separate output signals
to the programmable timer to set the pump time in addition to any
output signals to the pump for delivering oil for the amount of
time set by the timer.
[0026] The temperature controller senses the rapid drop in kettle
temperature associated with the absorption of heat from the kettle
by the corn and oil. When the temperature drop exceeds a set
amount, for example, 50.degree. F. below the equilibrium start
temperature, the PLC initiates a cooking cycle. The point of
initiation of the cooking cycle is designated the cycle temperature
or cycle point.
[0027] As the cooking cycle progresses, the PLC senses through the
temperature controller, that the kettle has dropped to a minimum
temperature below the cycle temperature. The minimum temperature
will depend upon the heat load added to the kettle. As the popcorn
pops, the temperature of the kettle begins to rise above the
minimum temperature. When the kettle temperature reaches a
predetermined dump temperature or dump point and the PLC that the
minimum temperature was previously reached and was preceded by the
cycle temperature, the popper indicates that the end of the cooking
cycle has occurred. Preferably, the predetermined kettle dump
temperature associated with the dump point for determining the end
of a cooking cycle is equal to the cycle temperature associated
with the start of the cooking cycle, i.e., approximately 50.degree.
F. below the equilibrium start temperature, for example. Upon
sensing the end of the cooking cycle at the dump point, the PLC
initiates a dump cycle and controllably energizes the dump motors
to tilt the kettle and dump the finished popcorn onto the surface
platform. The popcorn is immediately and automatically dumped at
the end of a proper cooking cycle, therefore preventing the popcorn
from burning. Furthermore, because of the unique temperature-driven
control of the popper, the popcorn is consistently and properly
cooked and may be served at the peak of freshness. The greater the
amount of corn and oil added, the longer the cooking cycle.
Conversely, the less the amount of corn and oil, the shorter the
cooking cycle.
[0028] Preferably, the motors are controlled to dump the kettle
twice to ensure complete dumping. After the first dump, the kettle
is only partially returned to a cooking or popping position. It is
then dumped again before fully returning to a popping position.
[0029] When the temperature controller indicates that the kettle
temperature is below the cooking cycle point and the machine is in
a cooking cycle, the PLC disables the dump motors and thus prevents
inadvertent dumping of the kettle contents.
[0030] When the popcorn has been dumped at the end of a cooking
cycle, the kettle will heat back up to the start cook point again,
and audible and visual indications are again initiated to remind a
busy operator to reload the kettle with fresh ingredients. This
prevents delays in between consecutive batches of popcorn and thus
increases the efficiency of the operator and the popcorn popper,
increasing production rates and profitability.
[0031] The present invention provides the proper application of
heat energy consistently to batches of corn kernels. In that way,
the kernels are heated to a sufficient temperature to provide
proper hull brittleness and expansion when the kernels pop but the
heat is not so high so as to force out the steam in the kernel
prematurely. Therefore, the invention achieves the desired corn
temperature and peak steam pressure for proper expansion. Expansion
rates of approximately 1:50 have been achieved with the invention
which is a significant improvement over some conventional devices
which achieve expansion rates of 1:44 or lower.
[0032] Therefore, the present invention automates the cooking and
dumping of popcorn and eliminates the need for constant operator
attention to the process. Production of consistently popped corn is
increased as is the profitability of the operation while incidents
of burned corn and inadvertently spilled oil or uncooked corn are
eliminated. Furthermore, the temperature control of the kettle
operation and the cooking cycle provides properly and consistently
cooked batches of popcorn.
[0033] The above and other objectives and advantages of the present
invention shall be made apparent from the accompanying drawings and
the description thereof.
BRIEF DESCRIPTION OF THE DRAWING
[0034] The accompanying drawings, which are incorporated in and
constitute a part of this specification, illustrate embodiments of
the invention and, together with a general description of the
invention given above, and the detailed description of the
embodiments given below, serve to explain the principles of the
invention.
[0035] FIG. 1 is a perspective view of a popcorn popper apparatus
in accordance with the principles of the invention;
[0036] FIG. 1A is a perspective view of the top of the popcorn
popper of FIG. 1;
[0037] FIG. 1B is perspective view of the popcorn popper of FIG. 1
illustrating the oil pump system.
[0038] FIG. 2 is a cross-sectional view of a popcorn popping kettle
as seen on line 2-2 of FIG. 1;
[0039] FIG. 3 is a cross-section taken along lines 3-3 of FIG.
2;
[0040] FIG. 4 is a perspective-view of the kettle of the popcorn
popper of FIG. 1;
[0041] FIG. 5 is a perspective view of the kettle of FIG. 4 removed
from its housing for cleaning;
[0042] FIG. 6 is a diagrammatic view of the electrical components
of the popcorn popper of FIG. 1;
[0043] FIG. 7 is an operation flowchart of the popcorn popper
apparatus of the invention; and,
[0044] FIG. 8 is a temperature graph versus time of the kettle
during a popcorn cooking cycle.
DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS
[0045] Turning now to the drawings, there is shown in FIG. 1 an
automated corn popper 10 according to the invention. It will be
appreciated that the popper is operable to cook or to pop popcorn
and is particularly useful for cooking consecutive batches of
popcorn for sale for use by concessionaires at movie theaters,
sport events, fairs and the like.
[0046] The corn popper 10 includes a cabinet having transparent
wails including two sidewalls 11, 12, a rear wall 13, front wall
14, and a service platform 17 for catching popcorn. Front wall 14
includes two doors 15, 16, which can be opened to gain access, both
to the popped corn on the platform 17 of the cabinet and to the
kettle 18. Sidewalls 11, 12 and rear wall 13, as well as the front
wail 14 including doors 15, 16, are all made preferably of
transparent glass or plastic material so that the interior of the
cabinet can be viewed from the exterior. The cabinet may also
include various operating switches and light indicators on an
operating panel 25 for turning ON kettle heat, the dump motor, a
warmer (not shown) under platform 17 and lights inside the cabinet
as well as turning ON the heaters and pumps of an oil pump system
(see in FIG. 1B) for providing cooking oil for the operation. The
lights may indicate that one or more of these systems are ON.
Various of these systems will now be described in greater detail in
accordance with the principles of the present invention.
[0047] The cabinet of popper 10 also preferably includes an oil
pump system 36 which would rest below the platform in the cabinet
(see FIG. 1B). The oil pump system 36 provides oil to the kettle
during a cooking cycle and might be one of various different
systems. For example, Gold Medal Products Co. of Cincinnati, Ohio,
which is the owner/assignee of the present patent application,
markets the Model 2114 Accumeter Bucket Pump for pumping popcorn
oil. Another system, Model 2257 Rack Oil Delivery System, is also
available from Gold Medal Products and is discussed in U.S. patent
application Ser. No. 08/541,469 entitled "Oil Supply for Popcorn
Poppers", which application is incorporated herein by reference in
its entirety. While those oil systems manufactured by Gold Medal
Products Co. are preferable, the present invention might be
utilized with other systems as well.
[0048] The popping kettle 18 is of any suitable variety having a
heater (not shown in FIG. 1) interconnected by a control line 19 to
a power plug 20 mounted inside on the top 21 of the cabinet, It
will be appreciated that the kettle 18 is tiltable about a tilt
axis 22 (FIG. 2) and is provided with covers 23 and 24 which are
pivoted on the kettle 18. When the corn is popped, it pushes these
covers open and falls out the sides of the kettle onto platform 17.
Moreover, it will be appreciated that the cover 23 is located over
a so-called "dump section" or side of the kettle 18. When the
kettle is tilted, this cover pivots open to facilitate dumping of
popcorn onto platform 17.
[0049] Positioned between covers 23, 24 is an oil funnel 29 which
has a flared funnel mouth 30. When the kettle 18 is upright as
shown in FIG. 1, the funnel 29 aligns with an oil outlet 37 which
is coupled via a delivery tube 39 to oil pump system 36. Oil is
pumped up by system 36 to drain into funnel tube 29 and kettle 18
for use during a cooking cycle as discussed in greater detail
hereinbelow.
[0050] The kettle 18 includes an internal agitator, stir blade or
rotor 38 (FIG. 3) driven by a rotor drive shaft 26 having an upper
pilot end 27 and a driven gear 28 thereon. Referring to FIG. 4,
when the kettle is in a cooking position as shown in FIG. 1, the
upper pilot end 27 of the rotor drive shaft 26 is located in a
socket 31 defined in a rotor drive housing 32 adjacent a drive
shaft 33 and a drive gear 34. The drive gear 34 intermeshes with
the driven gear 28 on the upper pilot end 27 of the rotor drive
shaft 26 to drive the rotor within the kettle to promote popping.
Directly above socket 31 in drive housing 32 is a position sensor
35 which determines that shaft 26 is seated in socket 31 and kettle
18 is in a cooking position. The sensor 35 promotes more accurate
positioning of the kettle after it is tilted as discussed in
greater detail below. The stir blade and shaft 26 are rotated by
stir motor 68 which is activated by an appropriate operating switch
on the panel 25 or by the controller of the invention as discussed
below.
[0051] Referring again to FIG. 3, the blade 38 of the invention is
weighted to prevent popcorn from being trapped against the blade
during a dump cycle. As discussed further hereinbelow, the kettle
18 is tilted or dumped during a cycle to dump out the cooked
popcorn. To prevent hindrance of the popcorn by blade 38, the blade
is weighted on one side with an appropriate weight element 47 which
causes the blade to rotate to a downward or generally vertical
position during a kettle dump cycle. The blade 38 is then out of
the way of the dumped popcorn so that popcorn falls freely from the
kettle.
[0052] The kettle is mounted in the cabinet of the popper 10 by way
of a drive housing 40 and a spring-like hanger bracket 41. The
spring-like hanger bracket 41 includes an L-shaped bracket having a
foot 42 for interconnection to the top 21 of the cabinet. The
depending flat spring leg 43 is provided with an aperture or slot
44, as will be further described.
[0053] On the other side of the kettle, the drive housing 40 houses
the drive shaft 48, which is provided with a worm gear 49 on the
bottom end thereof. A drive stub shaft 50 is provided with a gear
51 for intermeshing with the worm gear 49. The opposite end of the
drive stub shaft 50 is provided with a drive stub 52 disposed in a
socket 53 of the drive housing 40. The upper end of the drive
housing 40 is provided with a mounting foot 54 for securing the
drive housing 40 to the top 21 of the cabinet of the popper 10. In
addition, it will be appreciated that the drive shaft 48 can be a
one-piece drive shaft or it can be coupled through a coupling 55 to
the depending drive shaft 56 of a dump motor 58 (FIGS. 1 and 1A).
Drive shaft 48 is journaled in a blind bore 45 located in an
externally threaded bushing 46 in the bottom of housing 40 (FIG.
3). This prevents lubricants from leaking into the popped pop
corn.
[0054] The kettle 18 is provided with a drive boss 60 and a hanger
boss 61. The drive boss 60 is provided with a slot 62 for receiving
the drive stub 52, supported by the drive housing 40. The hanger
boss 61 extends from the other side of the kettle with respect to
the drive boss 60 and is provided with a groove 63 for receiving
the depending leg 43 of the hanger bracket 41. In this regard, the
groove 63 fits within a slot or aperture 44 of the hanger bracket
41 so that the kettle can be rotated about the pivot axis 22. At
the other drive side of the kettle, the drive boss 60 resides in
the socket 53, defined by the drive housing 40, so that the drive
boss 60 can rotate in that socket. It will be appreciated that the
socket has an opening 64 for accommodating radial movement of the
drive boss 60 with respect to the socket and to the drive stub 52
when the drive stub 52 and the recess 62 in the drive boss 60 are
aligned with the opening 64 to permit the drive boss to be moved
outwardly of the socket.
[0055] Alternatively, the kettle could be supported in a
cantilevered fashion only by the drive boss or other supporting
apparatus as will be appreciated.
[0056] Turning now momentarily to FIG. 1A, there is shown a
perspective view of the top of the popper 10 showing various
components of the popper mounted outside the cabinet on the top 21
thereof including parts of the kettle operating system. The kettle
operating system as it is termed herein includes the kettle heaters
(not shown) and the kettle dump motor 58 as well as the control
components which operate the popper in accordance with the
principles of the invention.
[0057] As shown in FIG. 1A, the dump motor 58 is mounted on the top
21, such that drive shaft 56 extends downwardly through the top 21
and into the drive housing 40 (FIG. 3). A rotor drive motor or stir
motor 68 is also positioned on the top 21 so that its drive shaft
33 extends downwardly through the top 21 and through the housing 32
for interconnection with the drive gear 34. A buzzer 70 is
positioned preferably on the top 21 as shown, as well as a cabinet
light 75, a ventilator 76 and various support circuitry for the
components, including a Programmable Logic Controller (PLC) 77, a
temperature controller 82, and a solid state relay 86 to the kettle
heaters.
[0058] The control components for the control system of the
invention comprise a Programmable Logic Controller, or PLC, such as
a PLC made by Omron Electronics, Inc., One East Commerce Drive,
Schaumburg, Ill. 60173, under the Model No. C20R. PLC 77 is
connected to dump motor 58 through an UP relay 78 and a DOWN relay
79. The PLC is also connected to the audible buzzer 70 and to light
71 for audibly and visually notifying an operator when the kettle
18 is ready to receive another batch of popcorn, oil, salt and
other ingredients. The visual indicator light 71, which may be
positioned on control panel 25, flashes to visually alert an
operator that the kettle is ready for another batch of ingredients
simultaneous with the buzzing of buzzer 70. The visual indicator
light 71 will provide a visual indication to an operator and is
particularly helpful in the case of multiple machines in an area
where it may be difficult to determine which one is buzzing. The
PLC 77 provides output signals to the dump motor relays 78 and 79
to tilt the kettle and dump the popcorn cooked therein at the
cessation of a cooking cycle. Output signals from the PLC 77 to the
buzzer 70 and light 71 produce an audible signal and a visual
signal which ensure consecutive batches of fresh popcorn without
delays between batches as are normally associated with conventional
popcorn machines.
[0059] The present invention is operable to monitor the temperature
of the kettle to automatically alert the operator to load
ingredients to automatically begin a cooking cycle when ingredients
are loaded, and to end the cooking cycle and automatically initiate
a dump cycle to empty the popcorn and again alert the operator to
load more ingredients for the next batch. The invention monitors
the kettle temperature and determines at certain temperature
checkpoints which operations are to be automatically executed.
Therefore, the popper of the invention may be loaded with corn
and/or oil and then ignored until the next ingredients load to free
the operator to handle other tasks. To that end, the control system
of the invention further comprises a temperature controller 82 to
control the heating of kettle 18 and to provide input signals to
the PLC 77 for initiating a popcorn cooking cycle and subsequently
for controlling dump motor 58 to dump finished popcorn from the
kettle after a cooking cycle is complete. The temperature
controller 82 has an output line 84 which is operably coupled to a
solid state relay 86 connected to kettle heater 88. To provide a
temperature input to the PLC, a thermocouple 90 is operatively
connected to kettle 18 close to kettle heater 88 to monitor the
temperature of the kettle. An output signal on line 92 from the
thermocouple is input into the temperature controller 82. Through
thermocouple 90 and line 92, the temperature controller 82 monitors
the temperature of kettle 18 and turns power to the heater 88 ON
and OFF through solid state relay 86 to maintain the temperature at
a predetermined start temperature or equilibrium temperature.
Preferably, the start temperature is approximately 500.degree. F.
to 525.degree. F., although it will be appreciated by one of
ordinary skill in the art that such a temperature might be varied
up or down for a particular size kettle or other variable cooking
conditions.
[0060] The temperature controller 82 communicates on line 94
directly with the PLC 77. Line 94 is a low temperature alarm line
which is utilized to set the beginning of the cooking cycle and to
initiate a kettle dump at the end of the cooking cycle. As
described further hereinbelow, temperature controller 82 sends an
input signal on line 94 to the PLC 77 when thermocouple 90
indicates that the kettle temperature has dropped below a
predetermined temperature or low alarm temperature, such as when
uncooked popcorn kernels and oil are poured into the kettle 18, and
through thermal loading, cause a rapid decrease in the kettle
temperature. The falling temperature passing through the low alarm
temperature point 149 indicates that a cooking cycle has been
started (See FIG. 8). As may be appreciated, as the popcorn in
kettle 18 cooks, the thermal load is reduced and the temperature of
kettle 18 begins to rise again. The kettle temperature will again
pass through the low alarm 150 temperature point, except this time
as a rising temperature rather than a falling temperature, the
rising temperature passing through the alarm point indicates the
end of the cooking cycle (See FIG. 8). At such a time, a signal is
sent on line 94 to the PLC 77 to initiate a kettle dump procedure
to dump the cooked popcorn onto service platform 17 as discussed
below. While the low alarm temperature may be variably adjusted in
temperature controller 82, it is preferably set to be approximately
50.degree. F. to 75.degree. F. below the start temperature
referenced above, e.g., it may be set to be approximately around
425.degree.-500.degree. F., depending upon the preferred start
temperature. The temperature point indicating the temperature 149
as it first falls through the low alarm temperature when uncooked
popcorn is added to the kettle is designated the cycle temperature
or cycle point as it indicates to the PLC the beginning of an
official cooking cycle. A cooking cycle is not begun until the
kettle drops below the cycle temperature 149 to prevent false
cycles which might occur as the empty kettle fluctuates around the
start temperature (see FIG. 8). That is, the substantial drop from
the start temperature will indicate that corn and oil have been
added to the kettle. The subsequent point 150 wherein the
temperature increases back up to the low alarm temperature after
the popcorn is cooked and popped is considered the dump point or
dump temperature because the PLC initiates a kettle tilt to dump
the popcorn at that temperature. Preferably, the cycle temperature
149 and 150 and dump temperature are approximately the same (see
FIG. 8), e.g., approximately 475.degree. F. However, it may be
appreciated that the temperatures might also be offset from each
other. Both the cycle temperature and dump temperature are below
the start temperature point.
[0061] In order to ensure stable heating of kettle 18, the
temperature controller 82 will preferably cycle solid state relay
86 and heater 88 ON and OFF numerous times as the kettle
temperature closely approaches the equilibrium start temperature.
This reduces substantial conditions beyond levels 142 and 152 of
the kettle temperature which might occur should the heater be
turned OFF only at the time that the kettle reaches the start
temperature due to thermal transients in the system. A suitable
temperature controller for use with the invention is the Model 935
Proportional Integral Derivative or PID, programmable temperature
controller available from Watlow, 1241 Bundy Blvd., P.O. Box 5580,
Winona, Minn. 55987-5580. The Model 935 temperature controller 82
is capable of monitoring when the kettle temperature is getting
close to the equilibrium start temperature and operably slowing
down the heating process as that start temperature is approached.
The Model 935 temperature controller also has an alarm silence
feature which prevents kettle dumping when the kettle is heating up
upon initial powerup. For example, as discussed above, temperature
controller 82 monitors a rising temperature which reaches the
predetermined low alarm temperature in order to indicate the end of
a cooking cycle and to control the dump motor 58 to dump the
kettle. As may be appreciated, a rising temperature passing through
the low alarm temperature is a scenario which will occur upon
initial powerup as the kettle heats from a cold state to an
equilibrium start temperature. In order to prevent a kettle dump at
initial powerup, temperature controller 82 has a start override
feature to ignore the first rising pass 151 through the
predetermined low alarm temperature (See FIG. 8).
[0062] As the temperature controller 82 monitors the kettle
temperature, it controls the operation of the heater 88 through
solid state relay 86. The present invention alerts an operator when
the kettle is ready to cook, and to indicate to the PLC 77 when
kettle temperature has reached the equilibrium start temperature, a
slave relay 96 is coupled to the output of relay 86 and provides an
input to the PLC 77 on line 93. When the solid state relay 86 is
closed to provide power to the heaters 88 to heat kettle 18, a 24V
signal is delivered to PLC 77 through slave relay 96. When the
solid state relay 86 closes and turns power to heater 88 OFF and
remains OFF, indicating that the kettle has reached start
temperature, (e.g., 525.degree. F.) the slave relay 96 stops the
signal to the PLC 77 and the PLC, in response, provides an output
to buzzer 70 and light 71 to produce an audible and visual
indication and alert the operator that the kettle is ready to cook
popcorn. With consecutive batches of popcorn, buzzer 70 and light
71 will again be energized to provide an audible and visual
indication indicating that the popcorn has been cooked and dumped
and the kettle is ready for another batch of popcorn kernels. In
that way, consecutive batches are made without delay.
[0063] The PLC 77 is also coupled to the kettle heat switch 80 to
monitor when the kettle heat to popcorn popper 10 is turned ON and
OFF. When power to the kettle heater 88 is turned OFF, the PLC 77
will internally reset a status bit. Thus, the PLC is not fooled
into initiating a kettle dump when the power is turned OFF and then
ON again, and in that way, the PLC 77 further prevents inadvertent
dumping. For example, when the power and the heat to the kettle are
turned ON by turning on switch 80 to deliver power to relay 86, the
PLC 77 monitors the kettle temperature through temperature
controller 82. If the heat 80 is then turned OFF, kettle
temperature would drop, simulating thermal loading of the kettle
with fresh popcorn and oil when indeed no popcorn or oil is loaded.
If the kettle heat is then again turned ON, the PLC 77 may note the
rising temperature passing through the low alarm temperature point
and thus may believe that a batch of popcorn has been cooked and
that it is time to dump the kettle. By resetting the PLC 77 status
bit upon an interruption of power to the heater 88, such a scenario
is avoided. A high limit switch 98 is coupled to the kettle heater
88 to cut off the power to the heater if the kettle temperature
exceeds a set upper limit, such as if the solid state relay 86
stays open or the temperature controller malfunctions.
[0064] The stir motor 68 turns a blade (not shown) during the
cooking of the popcorn. In one version of the invention, stir motor
68 is turned on by a switch at the operating panel 25 and stays on.
Alternatively, power to the stir motor is routed through PLC 77 and
is controlled by PLC 77 as noted by line 73. PLC 77 operates the
stir motor 68 so that the blade stirs automatically only during a
cooking cycle and stops when the cooling cycle is complete
independent of operator attention.
[0065] The oil for cooking the popcorn may be delivered either by
hand, by the operator actuating a switch on the operating panel 25
which is coupled to pump system 36, or alternatively may be handled
automatically through PLC 77 to automatically deliver oil at the
initiation of a cooking cycle. Oil pump system 36 preferably
includes a reservoir 101, a control housing 103, and a pump 104 to
pump oil from the reservoir. The pump system 36 will also usually
include a heater (not shown) for heating congealed oil to a liquid
state before pumping. The heater may be operably coupled to the
control panel so that the oil may be properly heated for being
pumped to kettle 18.
[0066] In one embodiment of the invention, the oil pump 104 is
operably coupled to an oil pump switch 106 which is located at the
operating panel 25. When the kettle heat switch 80 is ON and the
kettle heats to the start temperature, oil will be needed for a
cooking cycle in accordance with the principles of the invention,
oil pump switch 106 will be effectively disabled until all
conditions are proper for a cooking cycle. Switch 106 is operably
coupled to PLC 77 as indicated by line 111 and the PLC 77 is
operably coupled to oil pump 104 as indicated by line 113. PLC 77
disables switch 106 until the kettle heat switch 80 is ON, as
indicated by control line 115 between switch 80 and PLC 77, until
kettle 18 is upright, as indicated by proximity switch 35 coupled
to PLC 77, and until kettle 18 is properly heated as indicated by
the thermocouple 90 and controller 82. This prevents oil from being
pumped to funnel 29 from reservoir 101 until the kettle is hot and
in the proper position.
[0067] Upon enablement of the oil pump switch 106, the operator may
engage the switch to deliver a premeasured amount of oil from
reservoir 101. Generally, pump 104 will be controlled by a timer
129 (see FIG. 6) which may be adjusted by a mechanically adjusted
dial 117. In that way, the pump 104 will pump oil to kettle 18 for
a predetermined amount of time to deliver the proper premeasured
amount of oil. When the timer 129 times out, the pump 104 stops.
Upon delivery of the oil, PLC 77 will disable switch 106 so that no
more oil may be added until the next cooking cycle. In that way
excess, uncooked oil is generally not present in the kettle, thus
preventing any spills or messes. Pump 104 is coupled to line 39 for
oil delivery.
[0068] FIG. 1B illustrates the oil pumping system which is the
subject of U.S. patent application Ser. No. 08/541,469 and greater
detail about the operation of the system is given therein. Pump
system 36 is usually referred to as a bag-in-box system and
includes a container 118 on top of control housing 103 which holds
a flexible bag of oil 121. An oil tube 123 connects bag 121 and
reservoir 101. Alternatively, an oil bucket or pail system, such as
the Model 2114 Accumeter Bucket Pump (not shown) may be used.
[0069] In an alternative embodiment of the invention, the PLC 77 is
operably coupled to pump 104 and timer 129 by control lines 131, so
that delivery of oil is automatic. When the kettle 18 heats up, and
is in the proper upright position as discussed hereinabove, the PLC
77 will automatically actuate pump 104, instead of enabling switch
106 and requiring the operator to actuate the switch 106.
Therefore, oil is delivered automatically at the beginning of a
cooking cycle. The operator then only has to add popcorn kernels,
as the cooking cycle begins. Timer 129 will control how long pump
104 runs once it is actuated to deliver the proper amount of oil.
Timer 129 may be a programmable timer which is set by the PLC 77
control lines 131 and may be programmed for certain, preselected
amounts of oil for a batch. That is, the PLC 77 controls the timer
129 as opposed to a mechanical mechanism such as dial 117. Once the
timer 129 times out, pump 104 stops and will not be reactuated
until the next cooking cycle. As with the previous scenario, if the
kettle heat switch 80 is OFF, no oil is added to the kettle.
[0070] It will be understood that various combinations of oil
loading steps might be utilized in accordance with the principles
of the invention. For example, the oil pump 104 may require switch
actuation while the timer 129 is automatically programmed by PLC
77. In another version, the pump 104 may be automatically actuated
by PLC 77 while timer 129 is manually set by a dial 117 or other
mechanical device. The oil system 36 will generally include a
preheater (not shown) for liquefying the oil prior to pumping. The
preheater may be actuated at the control panel 25 or directly at
the control housing 103 of oil system 36.
[0071] As the popcorn and oil are cooked during the cooking cycle
and the kettle temperature begins to rise, it rises through the low
alarm temperature 150 point or dump point as discussed above. A
kettle temperature rise through the low alarm point or dump point
which was preceded by a cycle point indicates the end of a cooking
cycle and the invention is then operable to initiate a dump cycle.
At the initiation of the dump cycle, the PLC 77 actuates the DOWN
relay 79 to direct the dump motor 58 to rotate the kettle
downwardly and thus dump the contents. The down relay is actuated
for a predetermined period of time and then the relay is
deactuated. Assuming that the cooking position of the kettle as
illustrated in FIG. 1 is 0.degree., the kettle is rotated
approximately 180.degree. for the first dump to dump the popcorn
contents therefrom. That is, the kettle is turned upside down.
Subsequently, the PLC 77 actuates the UP relay 78 to energize dump
motor 58 and move the kettle 18 toward the cooking position.
However, the UP relay is only actuated to return the kettle
partially to its cooking position and in fact is preferably
energized for a time period sufficient to move the kettle to an
approximately 60.degree. angle between the 0.degree. cooking
position and the dump 180.degree. position. This partial return is
obvious to the operator and prevents him from believing the kettle
is in the cooking position. Therefore, the operator is not misled
into prematurely loading popcorn and oil into the kettle.
[0072] After the partial return toward the cooking position, the
DOWN relay 79 is again actuated to make the dump motor 58 rotate
the kettle downwardly to 180.degree. to again dump the popcorn
contents. The two-stage dump cycle of the present invention
provides proper and complete dumping of all the contents from
kettle 18 so that little or no popcorn remains in the kettle to be
burned during the next cooking cycle. After the second dump, the UP
relay 78 is actuated to energize dump motor 58 to return the kettle
to the upright cooking position. Thus, the kettle 18 is rotated to
a full dump position, partially returned, rotated to a full dump
position again, and then fully returned to the cooking position for
another cooking cycle.
[0073] Referring again to FIG. 4, when kettle 18 is returned to the
cooking position, the upper pilot end 27 of drive shaft 26 engages
socket 31, and in doing so will actuate the proximity switch 35.
Proximity switch 35 is preferably a metal detecting proximity
switch which indicates the presence of the shaft end 27. Upon
sensing the shaft end 27, the proximity switch 35 provides an input
to PLC 77 which then simultaneously actuates both the UP and DOWN
relays 78, 79 to lock the dump motor 58 and provide a secure stop
when the kettle is returned to the cooking cycle. Proximity switch
35 provides secure placement of the kettle in the cooking position
and allows rapid return of the kettle to that position without
slowing the motor down as the kettle approaches. The present
invention thereby prevents overshoot of the shaft end 27 and socket
31 and also ensures that the gears 28 and 34 are properly seated
for the next cooking cycle. The proximity switch also ensures that
oil can be added to the kettle 18 only when the kettle is
upright.
[0074] Upon the return of the kettle 18 to the cooking position
with the kettle heated back up to the start position, PLC 77 again
actuates buzzer 70 to provide an audible indication to the operator
that another batch of ingredients should be added to the kettle. In
that way, consecutive batches of popcorn are made with very little
delay between the batches. Thus, the productivity of the operator
and the popper 10 and the profitability of the entire operation, is
increased. PLC 77 operates to actuate buzzer 70 at ten second
intervals until new ingredients are loaded into the kettle 18. In
that way, the operator cannot ignore the popper 10 of the invention
as it will continue to alert him until another batch of ingredients
is loaded. If the buzzer is ignored for ten minutes, it will begin
to sound continuously.
[0075] Kettle 18 may also be removed and cleaned as described in
the parent application entitled AUTOMATED CORN POPPER referenced
above. To that end, the PLC 77 is operably coupled to a clean
switch 99. When the clean switch is actuated, PLC 77 is operable to
actuate the DOWN relay 79 and dump motor 58 to tilt the kettle 18
to a position between the cooking position and the full dumping
position. In this intermediate position, the plane of the drive
stub 52 is aligned with the opening 64 and the socket 53, thereby
permitting the drive bar 60 of the kettle to be lifted out of the
socket, cleaned, and then subsequently replaced for further popcorn
cooking as illustrated in FIG. 5.
[0076] Further understanding of the present invention may be
obtained by a discussion of the operation of the invention and
particularly to operation of PLC 77. An operational flowchart is
illustrated in FIG. 6.
[0077] Prior to beginning a cooking cycle or in order to clean the
kettle, the heat switch 80 should be OFF (block 95). The PLC 77
then checks to see if the kettle is cool (block 100). If the kettle
is cool, the clean switch 99 is enabled by the PLC 77 (block 102).
The clean switch may then be actuated to tilt the kettle 18 for
cleaning. The kettle is then cleaned and returned to the upright
position (block 127). As will be recognized, the kettle does not
always have to be cleaned, and an operator may proceed directly to
a cooking cycle wherein the process begins at block 105.
[0078] To begin a popping operation, the operator turns on the
various systems of the popper. For example, the operator would turn
ON the heat switch 80 to the kettle heater 88 to deliver power to
kettle heater 88 through the relay 86. If necessary, the kettle
stir motor 68 would be turned ON at panel 25 or may automatically
be controlled by the PLC 77. The oil pump system 36 and any
components, such as an oil preheater, might also be turned ON as
indicated by block 105. When the kettle heat switch is ON, the PLC
77 monitors the kettle temperature through temperature controller
82 as indicated at block 107 in FIG. 7. As the PLC 77 monitors the
temperature, it continuously checks to determine if the kettle
temperature has risen to the low alarm temperature point which may
indicate either that the kettle is initially heating up or is
returning to its equilibrium start temperature after having cooked
a batch of popcorn (see block 108). As indicated by line 109, the
PLC 77 will continue to monitor the kettle temperature until it has
risen to the low alarm temperature point. When it has reached the
low alarm point, as indicated by line 110, the PLC 77 determines
whether the system is initially being powered up and has not yet
cooked the first batch of popcorn (see block 112). As discussed
hereinabove, the temperature controller has a start override
feature which ignores the first rising temperature pass through the
low alarm temperature which indicates that the system is initially
being powered up. By ignoring the first low alarm temperature
point, the dump cycle is not initiated as indicated by block 114.
Otherwise, when the rising temperature returns to and passes
through the low alarm temperature point, a dump cycle would
normally be initiated according to block 116 because a low alarm
temperature point preceded by another low alarm point (cycle point)
will indicate the end of a cooking cycle and a dump point as
described above.
[0079] As the PLC 77 and temperature controller monitor the kettle
temperature, the PLC 77 checks to see if the kettle temperature has
risen to the equilibrium start temperature which is preferably
approximately 500.degree. F. to 525.degree. F., as indicated by
block 118. If the kettle temperature has not reached the start
temperature, the PLC 77 continues to monitor the kettle until that
temperature is reached according to line 119. When the equilibrium
start temperature has been reached, the system indicates that the
kettle is ready to be loaded with ingredients to cook a batch of
popcorn (line 120). At the start temperature, a buzzer is sounded
and a light flashed intermittently by the PLC 77 to notify the
operator that it is time to load popcorn ingredients and to start
cooking according to block 122. The buzzer will sound
intermittently at ten second intervals and will continue to sound
for ten minutes. If the operator ignores the buzzer for ten
minutes, and no ingredients have been loaded, the buzzer will then
sound continuously.
[0080] When the kettle is ready to cook, the PLC 77 checks to see
if the kettle is upright (block 130). If not, the buzzer sounds
continuously (block 132). If the kettle is upright, the oil pump
switch 106 is enabled (block 134). At this point, the oil pump
switch 106 may be manually actuated to add a premeasured amount of
oil to the kettle as described above (block 135). After oil is
added, the switch 106 will be disabled as discussed above, so that
no more oil may be added until the next cooking cycle.
Alternatively, the PLC 77 may automatically actuate the oil pump
system (block 137) as described above. At that point, popcorn is
also added to initiate a cooking cycle. As may be appreciated, the
automatic pumping of oil may be prevented until after the popcorn
is loaded and a cooking cycle is initiated, as shown by block 139.
In that way, oil introduction is not premature, such as when the
kettle heat switch is turned OFF while the buzzer is sounding and
light flashing to clean the kettle as discussed above. For example,
oil might not be automatically added until after the temperature of
the kettle full of popcorn drops, indicating the initiation of a
cooking cycle.
[0081] The PLC 77 then monitors the kettle temperature in order to
determine if the ingredients have been loaded. As discussed above,
the uncooked ingredients such as corn and oil will act as a heat
load and reduce the kettle temperature when they have been placed
therein. As noted in block 124, the PLC 77 will continue to monitor
the kettle temperature and if no ingredients have been loaded,
i.e., kettle temperature has not dropped (line 125), the buzzer
will continue to sound. If ingredients are loaded, the kettle
temperature will drop somewhat rapidly and will plunge below the
low alarm temperature point (cycle point) 149 of the temperature
controller (see FIG. 8). The buzzer then stops buzzing and the
light stops flashing. Popcorn is then cooked by the kettle (block
128).
[0082] As the buzzer 70 is sounding and light flashing 71, the
operator has the alternative options of turning the machine off or
loading ingredients. If the kettle heat switch 80 is turned OFF,
the system operation essentially returns to block 95 to determine
if it is safe to clean the kettle.
[0083] Returning now to block 128, as the popcorn is cooked, the
kettle begins to again heat up and the temperature controller 82
and the PLC 77 continue monitoring the kettle temperature to
determine if it has recovered or risen back up to the low alarm
temperature point (dump point) 150 and proceeded through that point
on its way back to an equilibrium start temperature (block 108). If
the kettle temperature has risen to the dump point and it is not an
initial power-up situation, as indicated by line 136, a dump cycle
will be initiated as described hereinabove (block 116). After the
dump cycle is initiated, the system either returns to block 95 if
the kettle heat switch is turned OFF to clean the kettle (line 138)
or will continue to heat the kettle up to its equilibrium start
temperature and will be ready for the next load of ingredients to
cook the next batch of popcorn. As illustrated by block 118 when
the start temperature has again been reached, the buzzer will again
sound to notify the operator to load ingredients. Also, the oil
pump switch will be enabled (block 134), after having been disabled
after oil was added for the previous batch.
[0084] In that way, the automated corn popper 10 of the present
invention only has to be loaded with ingredients to continually
produce successive batches of popcorn. Once the ingredients are
loaded, the operator can ignore the popper and the corn will be
properly cooked and dumped to be ready for serving. An audible
buzzer 70 and flashing light 71 will constantly remind the operator
when a new ingredients load is need and a cooperative working
relationship between the operator and the popper is developed for
producing consecutive batches of fresh popcorn efficiently and
safely while leaving the operator to more important tasks such as
selling the product. Furthermore, the temperature control of the
popper ensures that the right amount of heat is applied to each
batch of popcorn for consistently cooked popcorn. Still further,
the invention controls an oil pump system to ensure that the proper
amount of oil is added without excess.
[0085] FIG. 8 schematically illustrates the kettle temperature as a
function of time through initial power-up and a single cooking
cycle. When the kettle heat is turned on, the kettle 18 heats up
steadily until it reaches an equilibrium start temperature as
indicated by line 140. Preferably, an equilibrium start temperature
will be around 500.degree. F. to 525.degree. F., but may be
adjusted accordingly, depending upon the popcorn load and the size
of the kettle and other heating factors as understood by a person
of ordinary skill in the art. The temperature controller 82 of the
invention is programmed with the equilibrium start temperature and
will automatically monitor the kettle temperature to determine when
it begins to approach the start point 144. The temperature
controller 82 will cycle the heater 88 accordingly to prevent a
large amount of overshoot as indicated by the decreasing slope of
the curve as it approaches line 140. When the start temperature is
reached, the kettle heater 88 is cycled ON and OFF by relay 86 to
maintain the kettle close to the start temperature as indicated in
the curve section designated by reference numeral 142. When
ingredients, such as kernels and oil, are loaded, as indicated by
the load point 144, the kettle temperature drops off somewhat
rapidly as indicated on the curve by reference numeral 146.
Depending upon the popcorn and oil load, the kettle temperature
would drop to a low point 147, for example in FIG. 8, indicated
around 325.degree. F. As the kettle temperature drops, it will drop
through a low alarm point 149. This first low alarm point is
designated the cycle point or cycle temperature, because the PLC 77
sees it as the beginning of a cooking cycle.
[0086] As the popcorn cooks, the kettle temperature again begins to
rise as indicated by reference numeral 148 and will again pass
through the low alarm set point or dump point 150. At dump point
150, the end of the cooking cycle is indicated, and the PLC 77
responds by initiating a dump cycle. Therefore, the cooking cycle
is defined between the cycle point 149 and the dump point 150,
although some cooking of the popcorn will occur before the cycle
point 149 and after the dump point 150.
[0087] The dump cycle is a two-stage dump and empties the cooked
popcorn onto the serving platform to be sold. After the dumping
cycle, the kettle temperature again rises to the equilibrium start
temperature of 525.degree. F. and the heater will again be cycled
ON and OFF to keep the kettle at that temperature indicated on the
curve by reference numeral 152. At the start temperature, the
buzzer 70 will again sound and the light 71 will flash to indicate
to the operator that a batch of popcorn has just finished cooking
and that a new load of ingredients should be added to the
kettle.
[0088] Line 154 illustrates the signal on line 94 from temperature
controller 82 to the PLC 77. When the low alarm temperature points
are reached and exceeded (either cycle point or dump point) the
output from the temperature control cycles oscillates from high to
low at an internal frequency. The square wave signal is used
preferably to drive the intermittent buzzer 70 and flashing light
71. When the temperature of the kettle drops below the low alarm
temperature point, the output of temperature controller 82 stays
high, which indicates that a cooking cycle is ongoing.
[0089] As described, the present invention continuously and
properly cooks popcorn in consecutive batches with minimal
attention by the operator. Because the kettle is controlled by
temperature and the dump cycle is initiated automatically depending
upon the kettle temperature, the popcorn is not burned and is not
affected by operator inattention. Furthermore, the introduction of
oil is controlled for a proper, premeasured amount only once during
each cooking cycle. Messes and spills associated with the prior art
devices are reduced, and a reduction in the delays between fresh
batches of popcorn will increase the production rate of the popper
and thereby increase sales and profitability of the popper.
Furthermore, the present invention insures that a consistent and
proper amount of heat energy is always applied to the corn for
popping. The invention is not particularly susceptible to
environment variations, and will ensure that the proper amount of
heat energy is applied to a batch of corn. Larger batches will get
more heat energy and small batches will get less heat energy to
insure consistent popping.
[0090] The present invention also provides the proper amount of
heat to maximize kernel expansion at popping. With the heat
maintained at the proper level, the temperature of the corn and the
steam pressure in the kernels will cooperate to provide consistent
and high kernel expansion. With the present invention, popping
expansion of rates of 1:50 have been achieved which are a
significant improvement over the 1:44 or lower rates achieved by
the prior art.
[0091] While the present invention has been illustrated by a
description of various embodiments and while these embodiments have
been described in considerable detail, it is not the intention of
the applicants to restrict or in any way limit the scope of the
appended claims to such detail. Additional advantages and
modifications will readily appear to those skilled in the art. The
invention in its broader aspects is therefore not limited to the
specific details, representative apparatus and method, and
illustrative example shown and described. Accordingly, applicant
intends to be bound only by the claims appended hereto.
* * * * *