U.S. patent application number 11/443795 was filed with the patent office on 2006-12-14 for ice making machine and method of controlling an ice making machine.
This patent application is currently assigned to Manitowoc Foodservice Companies.Inc.. Invention is credited to Cary J. Pierskalla, Scott R. Rozmarynowski, Charles E. Schlosser, Robert L. VanMeter.
Application Number | 20060277937 11/443795 |
Document ID | / |
Family ID | 36930341 |
Filed Date | 2006-12-14 |
United States Patent
Application |
20060277937 |
Kind Code |
A1 |
Schlosser; Charles E. ; et
al. |
December 14, 2006 |
Ice making machine and method of controlling an ice making
machine
Abstract
An ice forming apparatus capable of forming ice pieces is
provided, including, a transfer zone between the ice forming
apparatus and a storage area, and an ice sensing apparatus
configured to both detect migration of the ice pieces through the
transfer zone and to detect build-up of the ice pieces in the
transfer zone. The ice forming apparatus is preferably an
auger-type device, such as a flaker-type or a nugget-type
device.
Inventors: |
Schlosser; Charles E.;
(Manitowoc, WI) ; Pierskalla; Cary J.; (Manitowoc,
WI) ; Rozmarynowski; Scott R.; (Greenville, WI)
; VanMeter; Robert L.; (Manitowoc, WI) |
Correspondence
Address: |
BRINKS HOFER GILSON & LIONE
P.O. BOX 10395
CHICAGO
IL
60610
US
|
Assignee: |
Manitowoc Foodservice
Companies.Inc.
|
Family ID: |
36930341 |
Appl. No.: |
11/443795 |
Filed: |
May 31, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60689387 |
Jun 10, 2005 |
|
|
|
Current U.S.
Class: |
62/344 ; 62/135;
62/340 |
Current CPC
Class: |
F25C 1/147 20130101;
F25C 5/20 20180101; F25C 2600/04 20130101 |
Class at
Publication: |
062/344 ;
062/340; 062/135 |
International
Class: |
F25C 1/00 20060101
F25C001/00; F25C 1/22 20060101 F25C001/22; F25C 5/18 20060101
F25C005/18 |
Claims
1. An ice making machine, comprising: a) an ice forming apparatus
capable of forming ice pieces; b) a transfer zone connecting the
ice forming apparatus with a storage area so as to permit migration
of ice pieces from the ice forming apparatus to the storage area;
and c) an ice sensing apparatus configured to detect at least some
of the ice pieces during the migration of the ice pieces through
the transfer zone.
2. The ice making machine of claim 1 wherein the transfer zone is
located with respect to the storage area so that a build-up of ice
pieces occurs in the transfer zone when the storage area is
full.
3. The ice making machine of claim 2 wherein the ice sensing
apparatus is configured to detect at least some of the ice pieces
during the build-up of the ice pieces in the transfer zone.
4. The ice making machine of claim 3 wherein the ice sensing
apparatus includes a movable portion having a first position
corresponding to the migration of the ice pieces and a second
position corresponding to the build-up of the ice pieces in the
transfer zone.
5. The ice making machine of claim 4 wherein the ice sensing
apparatus includes a first sensor to detect the first position of
the movable portion and a second sensor to detect the second
position of the movable portion.
6. The ice making machine of claim 4 wherein the movable portion
comprises a contact plate positioned along a path of the migration
of the ice pieces in the transfer zone.
7. The ice making machine of claim 6 wherein the ice sensing
apparatus further includes a rod coupled with the contact plate and
a signal member coupled with the rod, and wherein the contact plate
and the signal member are configured to pivot in unison between a
neutral position, said first position, and said second
position.
8. The ice making machine of claim 3 further comprising a
controller in electrical connection with the ice sensing apparatus
and the ice forming apparatus, wherein the controller is configured
to deactivate the ice forming apparatus if the ice sensing
apparatus fails to detect the migration of the ice pieces through
the transfer zone during a predetermined time period.
9. The ice making machine of claim 8 wherein the predetermined time
period is equal to a first duration during an initial start-up
operation of the ice making machine and is equal to a second
duration shorter than the first duration after the initial start-up
operation of the ice making machine.
10. The ice making machine of claim 9 wherein the controller is
configured to deactivate the ice forming apparatus if the build-up
of the ice pieces in the transfer zone is detected.
11. The ice making machine of claim 10 wherein the controller is
configured to immediately deactivate the ice forming apparatus if
the build-up of the ice pieces in the transfer zone is
detected.
12. The ice making machine of claim 1, the ice making apparatus
further comprising an auger.
13. A combination of the ice making machine of claim 1 and an ice
storage bin, the ice storage bin providing at least a portion of
said storage area.
14. An ice making machine, comprising: a) an ice forming apparatus
having an outlet section and being configured to form ice pieces
and; b) a transfer zone connecting the outlet section of the ice
forming apparatus with a storage area so as to permit migration of
ice pieces from the ice forming apparatus to the storage area; the
outlet section of the ice forming apparatus and the transfer zone
together comprising a clean zone; and c) an ice sensing apparatus
configured to detect the presence of ice pieces within the transfer
zone, wherein the ice sensing apparatus includes a first portion
located within the clean zone and a second portion positioned
outside the clean zone.
15. The ice making machine of claim 14 wherein the first portion of
the ice sensing apparatus comprises a contact plate positioned
along a path of the migration of the ice pieces through the
transfer zone.
16. The ice making machine of claim 15 wherein the second portion
of the ice sensing apparatus includes a signal member coupled with
the contact plate such that the contact plate and the signal member
are configured to pivot in unison between a first position and a
second position.
17. The ice making machine of claim 16 wherein the ice sensing
apparatus includes a sensor for sensing whether the signal member
is in the first position.
18. The ice making machine of claim 17 wherein the sensor is
substantially separated from moisture in the clean zone.
19. The ice making machine of claim 14 wherein the ice forming
apparatus includes an auger rotating about an axis within a cooling
chamber.
20. The ice making machine of claim 14 wherein the ice sensing
apparatus is configured to detect at least some of the ice pieces
during the migration of the ice pieces through the transfer
zone.
21. The ice making machine of claim 20 wherein the transfer zone is
located with respect to the storage area so that a build-up of ice
pieces occurs in the transfer zone when the storage area is full
and wherein the ice sensing apparatus is configured to detect at
least some of the ice pieces during the build-up of the ice pieces
in the transfer zone.
22. The ice making machine of claim 21 wherein the first portion of
the ice sensing apparatus is a contact portion located within the
clean zone and the second portion of the ice sensing apparatus is a
non-contact portion separated from the clean zone by a generally
fluid-tight seal.
23. A method of controlling an ice making machine, comprising: a)
forming ice pieces with an ice forming apparatus; b) permitting
migration of the ice pieces from the ice forming apparatus through
a transfer zone to a storage area; c) detecting at least some of
the ice pieces migrating through the transfer zone; and d)
deactivating the ice forming apparatus if no migrating ice pieces
are detected within a predetermined time period.
24. The method of claim 23 further comprising calculating the
predetermined time period based on a frequency at which the ice
pieces are formed.
25. The method of claim 23 wherein the step of forming ice pieces
includes rotating an auger about an axis within a cooling
chamber.
26. The method of claim 23 wherein the predetermined time limit is
equal to a first time during an initial start-up operation of the
ice making machine and is equal to a second time shorter than the
first time after the initial start-up operation of the ice making
machine.
27. The method of claim 23 further comprising, after the step of
deactivating the ice forming apparatus, reactivating the ice
forming apparatus after a delay time period.
28. The method of claim 27 wherein the step of reactivating the ice
forming apparatus includes randomly selecting the delay time period
from a database of potential delay time periods.
29. A combination of the ice making machine of claim 1 and an ice
dispenser configured to dispense at least a portion of the ice
pieces formed by the ice forming apparatus.
Description
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS
[0001] This patent application claims the benefit under 35 U.S.C.
.sctn. 119(e) of U.S. provisional patent application Serial No.
60/689,387, filed Jun. 10, 2005, which is hereby incorporated by
reference.
BACKGROUND 1. Field of the Invention
[0002] The present invention relates generally to an ice making
machine and a method of controlling an ice making machine. More
particularly, the invention relates to an ice making machine having
an ice sensing apparatus for the detection of ice pieces and a
method of controlling the ice making machine based on the
detection. Although the present invention is related to all types
of ice making machines, it is particularly suitable for use in an
auger-type ice making machine, such as a flake or a nugget making
machine. 2. Related Technology
[0003] In a conventional auger-type flake ice making machine, an
ice forming apparatus includes an ice making chamber that is cooled
to a relatively low temperature by a cooling fluid, such as
refrigerant. Water is delivered to the ice making chamber and
contacts the wall of the ice making chamber to form ice.
Furthermore, an auger is positioned within the ice making chamber
and has an auger flight with a diameter slightly less than that of
the ice making chamber wall. Therefore, as the auger rotates, the
auger flight removes portions of the ice from the chamber wall and
transports the ice in the upward direction towards an opening in
the top of the ice making chamber. The ice is expelled from the
opening and migrates towards an ice storage bin, where it is stored
until removed for consumption. More particularly, the storage bin
is typically located below the top of the ice making chamber so
that the ice pieces naturally fall through or slide along a
transfer zone, such as an ice chute.
[0004] Ice making machines currently include a control system to
ensure that all of the various ice-making components are properly
functioning. More particularly, the control system measures system
conditions to prevent possible damage to the system components,
such as the auger, the auger motor, and the ice making chamber.
[0005] One such control system, disclosed in U.S. Pat. No.
6,463,746, measures the current in the auger motor during
ice-making to prevent potential damage to the ice producing
machine. For example, if the current flow through the motor exceeds
a predetermined threshold, the system compressor is turned off.
However, this system may not be able to detect other types of
system failures, such as a failure to reach or maintain an
effective ice-making temperature in the chamber.
[0006] A similar control system to the one described above is an
auger rotation sensor disclosed in U.S. Pat. No. 6,609,387. A
sensor is coupled with the inner surface of the ice making cylinder
and a magnet is coupled to the auger rotating within the cylinder.
The sensor and the magnet cooperate to detect abnormal rotation of
the auger. However, as with the above-described design, this
control system fails to detect failures other than those relating
to the rotation of the auger.
[0007] Another control system, disclosed in U.S. Pat. No.
6,601,399, measures the rate of water consumption by measuring the
water level in the reservoir over a period of time. If the water is
not consumed at a minimum threshold rate, a controller adjusts the
capacity of the freezing circuit. However, as with the other known
designs, this system only detects a particular type of system
failure and is not able to detect if ice is actually being
produced.
[0008] In addition to failing to detect if ice is being produced,
the above control systems fail to detect the ice level within the
storage bin. Therefore, additional sensors are required to detect
when a desired amount of ice is in the storage bin, while
preventing an undesirable overflow condition in the storage bin or
in a transfer zone connecting the ice forming apparatus to the
storage bin.
[0009] One type of ice level detector, which is disclosed in U.S.
Pat. No. 5,172,595, is an ultrasonic sensor that is positioned at a
top portion of the storage bin. In this design, once the ice sensor
detects ice pieces at a relatively high threshold level in the
storage bin, a controller deactivates the compressor and prevents
the formation of ice until some of the ice is removed from the
storage bin and the ice drops below the threshold level. However,
the optical sensor is unable to detect normal ice migration from
the ice maker and therefore cannot be utilized to determine whether
the ice maker is functioning properly.
[0010] Another type of ice level detector, which is disclosed in
U.S. Pat. No. 5,142,878, includes a movable detection plate 32b
mounted at the top of a vertical delivery chute 31 that leads to a
storage bin 41. When the storage bin 41 becomes filled and the ice
pieces accumulate within the delivery chute 31, the ice pieces
cause displacement of the detection plate 32b, thereby opening a
proximity switch and stopping the ice making process. However, the
detection plate is only displaced when the ice pieces accumulate in
the delivery chute; not when ice pieces migrate through the
delivery chute 31 during normal ice making. Therefore, the
detection plate is unable to detect normal ice migration from the
ice maker and therefore cannot be utilized to determine whether the
ice maker is functioning properly.
[0011] Yet another type of ice level detector, which is disclosed
in U.S. Pat. No. 5,390,504, includes a switch assembly 20 mounted
at the top of a horizontal discharge passage and a movable
detection plate 15c mounted at the top of a vertical delivery chute
14. Both the switch assembly 20 and the detection plate 15c are
configured to be displaced by accumulated ice within the horizontal
discharge passage and the vertical delivery chute 14, respectively.
However, due to their location at the top of the horizontal
discharge passage and the vertical delivery chute 14, the switch
assembly 20 and the detection plate 15c are unable to detect normal
ice migration from the ice maker and therefore cannot be utilized
to determine whether the ice maker is functioning properly.
[0012] It is therefore desirous to provide an improved, low cost,
simple ice making machine, and an improved method of controlling
the machine, so as to reduce the risk of damage to the auger, the
auger motor, and the ice making chamber, and to achieve and
maintain a desired ice level in the storage bin.
SUMMARY
[0013] In overcoming the limitations and drawbacks of the prior
art, the present invention provides an ice making machine including
an ice forming apparatus capable of forming ice pieces, a transfer
zone between the ice forming apparatus and a storage area, and an
ice sensing apparatus configured to detect at least some of the ice
pieces during the migration of the ice pieces through the transfer
zone.
[0014] In one aspect of the invention, the ice sensing apparatus
further detects a build-up of the ice pieces in the transfer zone.
Furthermore, the ice sensing apparatus in this design may include a
movable portion having a first position corresponding to the
migration of the ice pieces and a second position corresponding to
the build-up of the ice pieces in the transfer zone. The ice
sensing apparatus in this design may also include a first sensor to
detect the first position of the movable portion and a second
sensor to detect the second position of the movable portion.
[0015] In another aspect, a method of controlling an ice making
machine is provided, including the steps of: a) forming ice pieces
with an ice forming apparatus, b) permitting migration of the ice
pieces from the ice forming apparatus through a transfer zone to a
storage area; c) detecting at least some of the ice pieces
migrating through the transfer zone; and d) deactivating the ice
forming apparatus if no migrating ice pieces are detected within a
predetermined time period.
[0016] The above aspects of the present invention therefore permit
monitoring of the ice-making operation to provide a simple, low
cost design for detecting the migration of ice pieces through the
transfer zone; thereby reducing part complexity and cost of the ice
making machine.
[0017] In yet another aspect of the present invention, the ice
forming apparatus includes an outlet section that cooperates with
the transfer zone to at least partially define a clean zone. The
ice sensing apparatus includes a first portion located within the
clean zone and a second portion positioned outside of the clean
zone. This aspect of the present invention reduces the amount of
moisture that is exposed to the second portion, thereby improving
the performance and the effective life of the sensor
components.
[0018] Further objects, features and advantages of this invention
will become readily apparent to persons skilled in the art after a
review of the following description, with reference to the drawings
and claims that are appended to and form a part of this
specification.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 is an isometric view of an ice making machine
embodying the principles of the present invention and including an
ice forming apparatus and an ice chute extending to the inlet of an
ice storage area;
[0020] FIG. 2 is an enlarged, isometric view of the ice making
machine and the ice chute shown in FIG. 1, having various
components removed therefrom for clarity purposes;
[0021] FIG. 3 is a cross-sectional view of the ice chute taken
along line 3-3 in FIG. 2, showing an ice sensing apparatus coupled
with the ice chute;
[0022] FIG. 4a is an enlarged view of the ice chute in FIG. 3,
where the ice sensing apparatus is in a first position, indicative
of migration of ice pieces down the ice chute;
[0023] FIG. 4b is an enlarged view similar to that shown in FIG.
4a, where the ice sensing apparatus is in a second position,
indicative of a build-up of the ice pieces in the ice chute;
[0024] FIG. 5a is a flowchart showing a method for operating an ice
making machine during a normal operation mode;
[0025] FIG. 5b is a flowchart showing a method for restarting an
ice making machine after a safety shutdown has occurred;
[0026] FIG. 6 is a top view of a water reservoir shown in FIG.
1;
[0027] FIG. 7 is a side view of the water reservoir shown in FIG.
6;
[0028] FIG. 8 is a front view of the water reservoir shown in FIG.
6;
[0029] FIG. 9 is an enlarged cross-sectional view taken along line
9-9 in FIG. 3, showing a portion of the ice sensing device; and
[0030] FIG. 10 is an exploded view of the auger and the casing of
the ice forming apparatus shown in FIG. 1.
DETAILED DESCRIPTION
[0031] The present invention will now be further described. In the
following passages, different aspects of the invention are defined
in more detail. Each aspect so defined may be combined with any
other aspect or aspects unless clearly indicated to the contrary.
In particular, any feature indicated as being preferred or
advantageous may be combined with any other feature or features
indicated as being preferred or advantageous.
[0032] Referring now to an embodiment of the present invention,
FIG. 1 shows an ice making machine 10 generally including an ice
forming apparatus 12 capable of forming ice pieces, a storage area
for storing the ice pieces (represented by an inlet tube 53 and an
ice bin 14, which is shown in phantom lines), a transfer zone, such
as an ice chute 16, for delivering the ice pieces to the storage
area, and an ice sensing apparatus 18 configured both to detect the
migration of the ice pieces along the ice chute 16 and to detect
the build-up of the ice pieces in the ice chute 16.
[0033] The ice making machine 10 includes components of a
refrigeration system that promotes heat exchange between a
circulating fluid, such as a refrigerant, and the ambient air. As
is well known in the art, gaseous refrigerant is drawn into a
compressor 11, which causes an increase in both the pressure and
temperature of the refrigerant. Exiting the compressor 11 in a
gaseous phase, the refrigerant is then condensed into a liquid
phase by a condenser 13. More specifically, a condenser fan 15
forces ambient air across heat exchange tubes 17 within condenser
13, thereby cooling the refrigerant flowing through the heat
exchange tubes 17. Next, the refrigerant flows through an expansion
valve (not shown), which causes the refrigerant to expand into a
low-pressure, low-temperature mixture of gas and liquid. The
mixture of gas and liquid then flows into an evaporator section
(not shown) of the ice forming apparatus 12 and cools an ice making
chamber 20 (as shown in FIG. 10) to a freezing temperature that is
preferably close to or below 5 degrees Fahrenheit (-15 degrees
Celsius).
[0034] As shown in FIGS. 2 and 10, a heat exchange tube 22 carrying
the refrigerant is utilized for cooling the ice making chamber 20.
More specifically, the heat exchange tube 22 extends into the ice
forming apparatus 12 near a lower portion of the ice making chamber
20, coils around a housing defining the ice making chamber 20, and
exits the ice forming apparatus 12 near an upper portion of the ice
making chamber 20. The coiled portion of the heat exchange tube 22
is surrounded by a casing 24 for insulative and protective
purposes. The casing 24 is preferably made of metal, such as a
tin-based solder.
[0035] Referring back to FIG. 1, ice making water is delivered from
a water reservoir 26 to a lower portion of the ice making chamber
20 via a supply tube 28. The ice making water is preferably
delivered to the ice making chamber 20 via natural flow forces. The
ice making water typically fills the ice making chamber 20 to the
same level as the water reservoir 26.
[0036] Furthermore, as shown in FIG. 10, an auger 30 is positioned
within ice making chamber 20 and includes a generally spiral-shaped
auger flight 32. The auger flight 32 has a diameter that is
slightly less than the diameter of the ice making chamber 20 so
that the auger flight 32 removes most of the ice build-up from the
ice making chamber 20 wall. For example, the auger flight diameter
is preferably between 0.001 and 0.01 inches smaller than the ice
making chamber diameter so that all but a thin layer of ice is
removed from the ice making chamber wall when the auger 30 rotates.
An auger motor 33 rotates the auger 30, via an auger drive gear
system 35 (FIG. 1), in a direction so that the flight generates a
lifting motion. As mentioned above, the ice making chamber 20 is
generally filled with water along the length of the auger 30 so
that the water adjacent to the ice making chamber wall is frozen
into ice crystals. Therefore, as the ice crystals are being formed,
the rotating auger flight 32 scrapes the layer of ice from the
inner surface and transports the newly-formed ice in the upward
direction.
[0037] Next, as shown in FIG. 10, the ice is separated into pieces
by an ice cutting head 37 having a plurality of generally vertical
blades 39. The leading edge of each of the blades 39 preferably has
a tapered portion 41 to act as a wedge and split the ice into ice
pieces 38 (FIGS. 4a and 4b). The ice cutting head 37 shown in the
figures is coupled to the auger 30 via a pair of bearings 43 so
that the ice cutting head 37 does not rotate along with the auger
30. Based on the size and shape of the cutting head, the ice
forming apparatus 12 can be used to form ice pieces 38 into a
desired shape and size.
[0038] Referring back to FIG. 2, the ice pieces 38 are then forced
upwards past the ice cutting head 37 and through an opening 34
defined by the ice making chamber 20 and the ice cutting head 37,
where a rotating ice wiper 36 sweeps the ice pieces 38 away from
the opening 34. The ice wiper 36, which includes a pair of
projections 40 coupled to a body portion 42, is connected to the
auger 30 such that the respective components 30, 36 rotate in
unison with each other. The body portion 42 has an arcuate, tapered
underside surface that gradually urges the ice pieces 38 in a
radial direction out of the opening 34. The ice that is extruded
through the ice cutting head 37 breaks into one of the ice pieces
upon contact with the underside of the body portion 42, thereby
forming one of the ice pieces 38. Therefore, the distance between
the tapered underside of the body portion 42 and the opening 34
controls the length of the ice pieces 38. Furthermore, as the auger
30 and the ice wiper 36 rotate, the projections 40 sweep the ice
pieces 38 further away from the opening 34.
[0039] Additionally, a nugget forming device (not shown) may be
positioned at the top portion of the auger 30 to compact the ice by
forcing the ice through generally small extrusion orifices. The
compacted ice is then cut or broken into relatively small nuggets
by an ice cutting component within the nugget forming device. In
addition to altering the shape and the size of the ice described
post-formation treatments squeeze out water clinging to the ice,
thereby causing the ice pieces 38 to have a higher cooling capacity
per pound of ice and increasing the cooling potential of the ice
pieces 38.
[0040] After being expelled from the ice making chamber 20, the ice
pieces 38 move through a transfer zone and into the ice storage
area. The transfer zone is defined by a path between the ice making
chamber 20 and the ice storage area. For example, the transfer zone
in the figures includes, but is not limited to, the area adjacent
to the ice making chamber opening 34, a strainer 50 (which will be
discussed in more detail below), and the ice chute 16.
[0041] The transfer zone is part of what is known as the food zone;
the area that often contains ice during normal operation of the
machine. For example, in the figures, the food zone includes, but
is not limited to, the following: the ice making chamber 20, the
area adjacent to the ice making chamber opening 34, the ice chute
16, and the storage bin inlet tube 53 and the ice bin 14. Because
the ice pieces 38 are typically used for consumption by people,
National Sanitation Foundation guidelines require that surfaces
that potentially contact food are made of food grade materials. For
example, a housing 45 defining the ice chute 16 and the storage bin
14 is preferably formed by food grade plastic and the auger 30 and
the inner surface of the ice making chamber 20 are formed by food
grade metal.
[0042] For purposes of the present invention, a portion of the food
zone is defined as a "clean zone". The clean zone 44 includes the
outlet section of the ice forming apparatus and the transfer zone.
Furthermore, a protective lid 46 (FIG. 1) covers the ice chute 16
and the area above the ice making chamber opening 34 to prevent
dust, dirt, and other contaminants from entering the clean zone 44
(the protective lid 46 has been removed in FIGS. 2, 4a, and 4b for
illustrative purposes only). The protective lid 46 is also
preferably constructed of food grade plastic. Additionally, the
protective lid 46 is preferably connected to the housing 45 by a
plurality of flanges 48 (FIG. 2) to prevent contaminants from
entering the clean zone 44 and to prevent heat exchange between the
ice pieces 38 and the ambient air.
[0043] As shown in FIG. 2, the strainer 50 is located between the
opening 34 and the ice chute 16 to prevent water, from melting ice,
from flowing down the ice chute 16. The strainer 50 preferably
permits drainage of water into a water recirculation tube 52. More
specifically, water flows through the strainer 50, along the water
recirculation tube 52, and back into the supply tube 28 to be
supplied to the ice making chamber 20. Alternatively, the water may
be discarded or recirculated to a different component in the ice
making machine 10. The strainer 50 has a slight, upward slope to
further prevent water from flowing down the ice chute 16.
[0044] After being formed in the ice making chamber 20, the ice
pieces 38 are forced away by the ice wiper 36, across the strainer
50, and towards the ice chute 16 by the rotating projections 40.
For example, the ice pieces 38 are initially directly contacted by
the ice wiper 36 and are forced onto the strainer 50. Next, due to
the upward slope of the strainer 50, the ice pieces 38 do not
typically migrate into the ice chute 16 by natural gravity forces
alone. However, subsequently-formed ice pieces 38 that are expelled
from the ice making chamber 20 force the ice pieces 38 across the
strainer 50 and into the top of the ice chute 16. The ice chute 16
is generally downwardly-sloping so that the ice pieces 38 are able
to naturally migrate down the ice chute 16 and are detected by the
ice sensing apparatus 18. After the ice sensing apparatus 18, the
ice pieces 38 migrate down a storage bin inlet tube 53.
[0045] The ice sensing apparatus 18 shown in the figures includes a
contact mechanism, the movement of which is caused by engagement
with the ice pieces 38. For example, the contact mechanism includes
a contact plate 54 positioned along the path of migration of the
ice pieces 38 such that the ice pieces 38 contact the contact plate
54 during migration towards the ice storage area. The contact plate
54 is pivotally supported via a rod 56 that extends along an axis
58 and that is rotatably supported by a pair of saddles 60,
sometimes known as bearings, on opposing sides of the housing 45.
More specifically, the saddles 60 are relatively smooth, low
friction surfaces conforming to the shape and the size of the rod
56 such that a low friction seal 62 is formed by the respective
components 56, 60, to permit low-friction rotation of the rod 56
and the contact plate 54. The low friction seal 62 may also prevent
some moisture from migrating along the rod 56.
[0046] As best shown in FIG. 3, the rod 56 includes an
enlarged-diameter collar portion 64 to prevent axial travel of the
rod 56 and to reduce the moisture migrating along the rod 56 by
forming an overlapped engagement with the housing 45. The rod 56
preferably snaps into engagement with the saddles 60 to prevent
disengagement therefrom. However, alternatively, the protective lid
includes a securing mechanism such as a tab with a semi-circular
recess to prevent vertical displacement of the rod 56.
[0047] The contact plate 54 is located within the clean zone 44,
and is therefore preferably made of a food grade material, such as
food grade plastic. Additionally, the contact plate 54 preferably
includes one or more slots 55 to permit water or small ice
fragments to flow past the contact plate 54 without causing the
displacement thereof. When the ice sensing apparatus 18 is not
being moved by the ice pieces 38, the contact plate 54 hangs
generally vertically in a neutral position 57, as will be discussed
in more detail below.
[0048] At least one of the end portions of the rod 56 preferably
extends through the housing 45 and out of the clean zone 44. For
example, a first end portion 66 extends through a first side of the
housing 45 and a second end portion 68 extends through the opposing
side of the housing 45. A signal member, such as an interrupting
vane 70, is coupled to the first end portion 66 of the rod 56 such
that the contact plate 56, the rod 56, and the interrupting vane 70
rotate in unison with each other. The interrupting vane 70 in the
figures is a generally thin, metal plate intersected by the rod 56.
The interrupting vane 70 is positioned adjacent to a sensor device
72 that detects the position of the interrupting vane 70, thereby
determining the position of the contact plate 54.
[0049] As shown in FIG. 9, the sensor device preferably includes
two Hall-effect sensors, including two magnets 74a, 74b facing a
first side of the interrupting vane 70 and two sensor elements 76a,
76b facing a second side of the interrupting vane 70. In the
figures, the magnets 74 are positioned on the inboard side of the
interrupting vane 70 and the sensor elements 76 are positioned on
the outboard side, but a reverse configuration may be used. In one
design, the Hall-effect sensors have a supply voltage between 4.5
and 5.5 VDC filtered, at least a 10 K.OMEGA. pull-down resistor
connected from the output to the ground, and a nominal 10 nF noise
capacitor connected from output to ground. When the interrupting
vane 70 is positioned between a magnet 74 and its sensor element
76, an electromagnetic field is disrupted and the sensor element 76
sends a signal to a controller 78 (FIG. 1). Whether the
interrupting vane 70 disrupts the electromagnetic field between
one, both or neither sets of the magnets and sensors 74, 76
indicates the position of the interrupting vane 70 and the contact
plate 54.
[0050] FIGS. 2, 3, and 9 show the interrupting vane 70 and the
contact plate 54 in the neutral position 57 so that the
interrupting vane 70 interrupts the electromagnetic field with two
sets of magnets and sensors 74a, 74b, 76a, 76b(causing the first
and second sensor elements 76a, 76b to be "closed"). The
interrupting vane 70 and the contact plate 54 are in the neutral
position 57 when the forces acting thereon are negligible or
non-existent. More specifically, the interrupting vane 70 and the
contact plate 54 are typically in the neutral position 57 when no
ice pieces 38 are migrating along the ice chute 16.
[0051] FIG. 4a shows migration 79 of the ice pieces 38 along the
ice chute 16 during normal ice making operation. More specifically,
a relatively low number of ice pieces 38 are discharged from the
ice making chamber 20 and permitted to migrate towards the inlet
tube 53 and ice storage bin 14, thereby actuating the contact plate
54 forward into a first position 80. When the contact plate 54 and
the interrupting vane 70 are in the first position 80, the
interrupting vane 70 is positioned between only the first magnet
74a and the first sensor element 76a of the sensor device 72,
thereby opening the first sensor element 76a and indicating to the
controller 78 the position of the contact plate 54. In this
position, the interrupting vane 70 defines a first angle 82 with
the vertical direction. In other words, when the contact plate 54
is contacted by the migration 79 of the ice pieces 38, the
interrupting vane 70 pivots forward from the neutral position 57 by
an amount equal to the first angle 82. After the ice pieces 38
migrate past the ice sensing apparatus 18, the contact plate 54
swings back to the neutral position 57 due to gravitational forces,
as will be discussed further below. Additionally, a magnetic force
from the magnets 74a, 74b also cooperates with the above-discussed
gravitational forces to urge the interrupting vane 70 towards the
neutral position.
[0052] FIG. 4b shows a build-up 83 of the ice pieces 38 along the
ice chute 16 when the ice storage area is full. More specifically,
a relatively high number of ice pieces 38 are prevented from
entering the ice storage area and become stacked upon each other
underneath the contact plate 54, thereby actuating the contact
plate 54 further forward into a second position 84. When the
contact plate 54 and the interrupting vane 70 are in the second
position 84, the interrupting vane 70 is positioned between neither
of the magnets 74 and the sensor elements 76 of the sensor device
72, thereby maintaining the open state of the first sensor element
76a, opening the second sensor element 76b, and indicating to the
controller 78 the position of the contact plate 54. In this
position, the interrupting vane 70 defines a second angle 86 with
the vertical direction that is greater than the first angle 82.
[0053] After the build-up 83 of the ice pieces 38 has been removed,
the contact plate 54 swings back to the neutral position 57 due to
the gravitational and magnetic forces. However, the build-up 83 is
typically not removed until some or all of the ice pieces melt or
until some of the ice pieces 38 have been removed from the ice
storage area, such as during ice dispensing. The latter of the two
events is more preferable and more likely to occur due to the
relatively cold temperature within the housing 45.
[0054] The second end portion 68 of the rod 56 includes a
counterweight 88 for balancing the weight of the interrupting vane
70. More specifically, the sensor element 70 and the counterweight
88 have generally equal weights to prevent the end portions 66, 68
of the rod 56 from being urged out of the saddles 60. Additionally,
the counterweight 88 may be designed to rotationally counter the
weight of the interrupting vane 70 to urge the contact plate 54
into the neutral position 57 (FIG. 2). For example, the
cantilevered nature of the counterweight 88 creates a rotational
torque on the rod 56, the contact plate 54, and the interrupting
vane 70 to urge the contact plate 54 into the neutral position 57.
More specifically, as shown in FIG. 4a, when the contact plate is
in the first position 80, the counterweight is in a first position
92 and urges the contact plate 54 into the neutral position 57.
Similarly, as shown in FIG. 4b, when the contact plate 54 is in the
second position 84, the counterweight is in a second position 94
and also urges the contact plate 54 into the neutral position
57.
[0055] Although unnecessary, a trough 96 is preferably formed in
the housing 45. This matches the trough in the sensor device 72 on
the opposing side of the housing 45 through which the interrupting
vane swings, to simplify tooling of the manufacturing machines. In
this manner the same part can be molded for both sides, although
magnets and sensors are added only to the sensor element 72.
[0056] The ice sensing apparatus 18 may alternatively be an
electronic apparatus, such as an optical sensor, an infrared
sensor, or any other suitable device. As another alternative
design, an alternative sensor element may be coupled with the
above-described, mechanically actuated ice sensing apparatus 18,
such as an optical sensor element to determine the position of a
mechanically actuated plate. In yet another alternative design, the
ice sensing apparatus 18 includes a single pair of sensor
components, such as a single magnet 74 and a single sensor element
76 that detect the position of the interrupting vane 70. In this
design, the ice sensing apparatus 18 may not be able to determine
the extent of rotation of the interrupting vane 70, but it may
determine the duration that the interrupting vane 70 is held in the
rotated state. The duration of the plate displacement is
particularly useful because the plate displacement caused by the
migration 79 of the ice pieces 38 typically occurs for a shorter
duration than the plate displacement caused by the build-up 83 of
the ice pieces 38. Therefore, the controller 78 can typically
determine which condition (normal ice migration 79 or ice build up
83) is occurring based on the duration of the plate
displacement.
[0057] The water reservoir 26 includes a first mechanism for
controlling the water level in the water reservoir 26 and a second
mechanism for deactivating the ice forming apparatus 12 if the
water level is below a predetermined threshold. For example, as
shown in FIGS. 6-8, the water reservoir 26 includes a float valve
100 configured to control a volume flow of water into the water
reservoir 26 and a water level sensor 102 configured to detect a
water level within the water reservoir 26.
[0058] The float valve 100 is a mechanically-actuated float valve
having a floating element 104, a valve 106, and an attachment arm
108 extending therebeween. When the floating element 104 is
positioned at or above a predetermined height within the water
reservoir 26, the arm 108 causes the valve 106 to be in a closed
position (as shown by the floating element 104 drawn in the phantom
line in FIG. 7). If the floating element moves below the
predetermined height, the arm 108 causes the valve 106 to move into
an open position, thereby permitting water to flow into the water
reservoir 26.
[0059] The water level sensor 102 is electrically connected to the
controller 78 to deactivate the ice forming apparatus 12 if the
water level in the water reservoir 26 drops below a predetermined
level. The water level sensor 102 includes a floating element 110
having a magnet coupled thereto and a guide arm 112 connecting the
floating element to a reed switch 114. The reed switch 114 detects
the position of the magnet on the floating element 110 to determine
a threshold water level within the reservoir 26. The water level
sensor 102 is configured to open an electrical circuit, indicating
to the controller 78 that the water level has dropped below a
predetermined level (as shown by the floating element 110 drawn in
the solid line in FIG. 7). However, if the water level is above the
predetermined level (as shown by the floating element 110 drawn in
the phantom line in FIG. 7), then the water level sensor will close
the electrical circuit. When the electrical circuit is open, the
controller 78 preferably waits 20 seconds before shutting down, as
is discussed in more detail below.
[0060] If the water level in the water reservoir 26 is undesirably
low, or if the water reservoir 26 is empty, the ice making chamber
26 may not receive a sufficient amount of water to make ice.
Additionally, the lack of water in the ice making chamber 20 may
cause the chamber temperature to drop to an undesirable level;
thereby causing damage to the ice forming apparatus 12. For
example, if no water is present in the ice making chamber 20, the
temperature therein will become too cold and the walls of the ice
making chamber 20 may be permanently deformed; thereby preventing
an effective scraping contact between the auger 30 and the walls of
the ice making chamber 20 and potentially damaging the auger
30.
[0061] The water reservoir 26 also includes an overflow tube 116
that diverts water if the reservoir 26 is overflowing. More
particularly, the overflow tube 116 includes a stand-up portion
116a that extends into the water reservoir 26 by a predetermined
distance. The predetermined distance is preferably greater than the
normal operational water level in the water reservoir 26, such that
when the float valve 100 is functioning properly the water level is
below the top of the stand-up portion 116a of the overflow tube
116.
[0062] Furthermore, the water reservoir 26 includes a drainage tube
118 for drain water from the water reservoir 26 when desired. For
example, when performing maintenance on and cleaning of the ice
making machine 10, it may be desirable to drain the water from the
system. During normal operation of the ice making machine 10, a
water dump solenoid valve (not shown) closes the drainage tube 118
to maintain the desired water level within the water reservoir
26.
[0063] Referring to FIG. 5a, a method 120 of controlling an ice
making machine will now be discussed. During an initial start-up
operation 122, the ice making machine 10 is activated and a
start-up operation timer located in the controller 78 resets and
restarts in step 124. Next, in step 126, the controller 78 inputs
signals from the first sensor element 76a to determine whether the
interrupting vane 70 has been displaced forward into the first
position 57. In other words, the controller 78 is determining
whether ice pieces 38 are being produced by the ice forming
apparatus 12. If no ice is formed for a start-up time period of
eight minutes, during step 127, then the ice making machine 10 is
deactivated and switched into a safety shutdown mode in step 128,
as will be discussed in further detail below. During the start-up
time period, if an error has occurred with the formation of ice,
the ice forming apparatus 12 typically does not undergo serious
damage to the auger 30 or the auger motor during the first eight
minutes of operating under this failure condition. More
specifically, upon start-up, the temperature in the ice forming
apparatus 12 is typically warm enough such that water in the ice
making chamber 20 will likely not freeze into a solid block during
the first eight minutes after start-up. Therefore, the eight minute
time period is typically a safe start-up time period. However, in
other configurations the start-up time period may be varied.
[0064] However, if no water is present in the ice making chamber 20
during start-up, the eight minute start-up time period may be long
enough to freeze the walls of the ice making chamber 20; thereby
causing deformation of the walls. Therefore, if the water reservoir
has an undesirably low level, the controller 78 will preferably
shut-down the ice making machine 10. For example, as mentioned
above, once the controller 78 is signaled that the water level is
below a predetermined level, the controller 78 will wait 20 seconds
before switching into safety shutdown mode. However, if the water
level rises to or above the predetermined level during the 20
seconds, the controller 78 will resume normal operation.
[0065] Once the first sensor element 76a indicates the production
of ice, the ice making machine 10 enters a normal mode of operation
in step 129 and resets and restarts the normal operation timer in
step 130. During the normal mode of operation 129, the controller
78 continues to input signals from the first sensor element 76a to
determine whether the interrupting vane 70 has been displaced
forward into the first position 57 in step 132. If no ice is formed
for a predetermined time period, then the ice making machine 10 is
deactivated and switched into a safety shutdown mode in step 128,
as will be discussed in further detail below. The term
"predetermined time period" refers to a time period that is
determined anytime before the predetermined time period begins. For
example, the predetermined time period may be a fixed time period
that is programmed into the controller. As another example, the
predetermined time period may be a variable time period that is
calculated by the controller.
[0066] The predetermined time period in the embodiment shown in
FIG. 5a is a variable activity window time period that is
calculated by the controller based on recent ice activity. If no
ice is detected during the variable activity time period, during
step 131, then the ice making machine 10 is deactivated and
switched into a safety shutdown mode in step 128. For example, the
variable activity window time period is period of time ranging from
a minimum of 90 seconds up to a maximum of 135 seconds that varies
based on recent ice making activity. More specifically, if the
previous X number of ice pieces have been detected at relatively
long time intervals, such as 80 seconds between the respective
displacements of the contact plate 54, then the activity window
will likewise be relatively high (where the variable "x" is a set
number programmed into the controller). However, if the previous X
number of ice pieces have been detected at relatively short time
intervals, such as 20 seconds between the respective displacements
of the contact plate 54, then the activity window will likewise be
equal to 90 seconds.
[0067] If ice is formed during the normal operation time period,
then the controller inputs signals from the second sensor element
76b to determine whether the interrupting vane 70 has been
displaced into the second position 84 in step 134. In other words,
the controller inputs signals to determine whether a build-up of
ice pieces 38 has occurred. If the build-up has occurred, then the
ice making machine 10 is deactivated and switched into a full bin
mode in step 129, as will be discussed in further detail below. If
no build-up has occurred, then the normal operation timer will be
reset and restarted. Therefore, during the normal operation of the
ice making machine 10, the ice forming apparatus 12 will be active
until no migrating ice piece 38 is able to displace the contact
plate 54 for a time period equal to the activity window or until
the build-up 83 of ice pieces 38 occurs.
[0068] Although the flowchart in FIG. 5a shows step 134 occurring
only after step 132 occurs, in an alternative embodiment the
controller immediately switches the system into the safety shutdown
step 129 as soon as the electromagnetic field associated with the
second sensor element 76b is open, regardless of the timing of the
disruption with respect to the ice making operation.
[0069] Referring to FIG. 5b, the safety shutdown mode 128 will now
be discussed. Generally, upon a system failure, the controller 78
will deactivate the ice making machine 10. The controller 78 will
then repeatedly attempt to restart the ice making machine 10 until
the expiration of a primary time period. The primary time period
permits the controller 78 to attempt a limited number of restarts
so that the system is able to overcome naturally solvable problems,
such as a low evaporator start-up temperature, but is not permitted
to perpetually attempt to overcome problems that require
maintenance or other intervention, such as a failed or an
undesirably low water supply.
[0070] After a system failure, the ice making machine waits for a
secondary time period before attempting to restart the ice making
machine 10. This secondary time period will provide the ice making
machine 10 with any time necessary to overcome the above-mentioned
naturally solvable problems.
[0071] As shown in FIG. 5b, in step 136 the controller 78
determines whether a restart indicator signal is equal to yes. If
the restart indicator signal is equal to yes, then the ice making
machine 10 has been restarted recently and the primary timer should
continue to run rather than being reset and restarted in step 137.
In other words, if the restart indicator is equal to yes, then the
primary timer should continue to run without being reset. However,
if the restart indicator is equal to no, then the ice making
machine 10 has not experienced a failure recently and the primary
timer should be reset and restarted.
[0072] Next, in step 138, a secondary timer resets and restarts
regardless of whether the ice making machine 10 has been restarted
recently. As mentioned above, the secondary timer calculates an
appropriate waiting period before attempting to restart. More
specifically, during step 140, a secondary time period is randomly
determined. For example, a predetermined base waiting period (such
as eight minutes) is added to a random time period (such as any
integer between 0 and 52 minutes) to determine the secondary time
period. Once the secondary time period is calculated, during step
142, the controller will continuously determine whether the
secondary time period has expired.
[0073] The random secondary time period may be advantageous to
improve the efficiency of the ice making machine 10 by having less
"down time" due to system errors. Many system failures may be
self-correcting with the deactivation of the ice making machine 10.
For example, if the ice in the ice making chamber 20 becomes too
thick and prevents rotation of the auger 30, the ice will melt
during a certain period of deactivation. However, it is often
impossible for the controller to predict the required duration of
this period of deactivation; thereby leading to the possible
scenarios where the deactivation period is too short and the ice
will fail to sufficiently melt and where the deactivation period is
too long and the ice making machine 10 is unnecessarily sitting
idle. Therefore, the random secondary time period results in a
series of varied deactivation periods over a series of shutdowns,
possibly resulting in an ideal deactivation period.
[0074] Once the secondary time period has expired, during step 144,
the controller determines whether the primary timer has been
running for a threshold amount of time, such as
[0075] 300 minutes. As mentioned above, if the primary timer has
been running for the threshold amount of time, the ice making
machine 10 will shutdown completely in step 146 and cease automatic
restarting attempts until the system is manually restarted by a
technician. However, if the primary timer has not been running for
the threshold amount of time, then the system will set the restart
indicator equal to yes in step 148 and restart the system in step
150, thereby returning to step 122 in FIG. 5a. When the primary
timer has expired and the ice making machine 10 enters shutdown
mode 146, the restart indicator is automatically set equal to "NO"
in step 145 so that the ice making machine 10 will not register a
recent restart event after the system is manually restarted.
[0076] The ice making machine 10 is further capable of operating in
various control modes. Generally, in a preferred design, the modes
are as follows: startup mode, normal ice mode, clean mode, safety
shutdown mode, bin full mode, and off mode.
[0077] Generally speaking, the startup mode is the mode when power
is applied or reapplied, commonly referred to as P.O.R. If a bypass
switch is not depressed during this state, then a five minute delay
is enforced prior to moving to the next state. The purpose of the
five minute delay is to protect the auger drive gear system 35 and
the compressor 11. For example, if the water in the ice making
chamber 20 happened to have been frozen to a point that the auger
drive gear system 35 would be damaged, this time period will allow
the ice to melt. Also, if the ice making machine 10 was running
when power was interrupted, the evaporator and the refrigerant
stored therewithin may still be cold upon reapplication of power.
If the relatively cold refrigerant is allowed to enter the
compressor 11, the compressor 11 may be damaged. Therefore, the
five minute time delay allows the evaporator to warm up naturally
and allows the liquid refrigerant to change into a gas state before
entering the compressor 11.
[0078] During startup mode of the ice making machine, startup mode
occurs if a toggle switch is in the "Ice"(on) position and the
sensor elements 76a, 76b are both closed. The toggle switch is a
manually operated switch that allows the end user to switch the ice
making machine 10 between different modes (ice making mode, off
mode, and clean mode). The control verifies the water-sensing
switch is closed, after which the gear motor starts immediately.
After a five second delay the compressor and fan motor start.
[0079] If the unit is in a restart situation, where the unit
stopped due to an open second sensor element 76b, a five-minute
time period must be timed out prior to starting. After the
five-minute time period, if the control verifies that the following
conditions are present then the gear motor starts immediately: the
first sensor element 76a is closed, the off time is less than 30
minutes, and the water-sensing switch is closed. After a five
second delay the compressor and fan motor start. The water dump
solenoid is energized for 30 seconds and then de-energized, thereby
opening and closing the drainage tube 118 to flush the water
reservoir 26 and provide fresh ice making water. After the water
sensing switch recloses, the compressor and fan motor start.
[0080] For both a nugget ice machine and a flaked ice machine,
during a power interruption restart (if the unit stops due to a
power interruption), upon restoration of power the unit will have a
five-minute time delay before the startup sequence is initiated.
During the time delay, a signal, such as a bank of LEDs, will
flash. The time delay will be bypassed if the bypass switch is
pressed. The control board may have seven LED's, which function as
follows: [0081] LED #1: NUGGET--Color RED, will indicate the
control is configured for nugget ice machines when illuminated.
[0082] LED #2: FLAKER--Color RED, will indicate the control is
configured for flaked ice machines when illuminated. [0083] LED #3:
HES#1--Color GREEN, will work in conjunction with Hall Effect
Switch #1. [0084] LED #4: HES#2--Color GREEN, will work in
conjunction with Hall Effect Switch #2. [0085] LED #5: CLEAN--Color
YELLOW, will indicate the unit is in a clean sequence when
illuminated. [0086] LED #6: MAINT--Color RED, will indicate that
maintenance is required. This LED is only used when the control is
configured for a nugget ice application. [0087] LED #7: WATER
OK--Color GREEN, will work in conjunction with the water-sensing
switch, when thee switch is closed, (adequate water to operate),
the light on, when the switch is open the light is off.
[0088] During normal operation mode, as described above, the ice
discharged from the evaporator will intermittently contact the ice
contact plate 54 as it falls into the bin. The control will see
intermittent opening and re-closing of the first sensor element
76a: this is used to determine that the unit is functioning
normally. During the first eight minutes of operation, the control
must see at least one opening and re-closing the first sensor
element 76a. After the first eight minutes of operation the control
must see at least one opening and re-closing of the first sensor
element 76aduring the activity window. If the control fails to see
this opening and re-closing of the first sensor element 76a, the
unit goes into a safety shutdown mode as described below. If at any
time during normal operation the water sensor switch stays open for
20 continuous seconds, the unit goes to a safety shutdown mode as
described below, and a "WATER OK" LED will flash.
[0089] At any point in the operation, if the second sensor element
76b is open, the unit goes into the full bin mode. In the shutdown
mode, the compressor/fan motor and the gear motor are de-energized
immediately. Once the unit stops, it must remain off for five
minutes before it is allowed to restart as described above. During
the shutdown period, the LED associated with HES#2 will flash
indicating a full bin condition if the second sensor element 76b is
active.
[0090] In order to determine when the system is to be cleaned, a
timer monitors and tracks the time (in hours) between clean or
flushing activities. On power up, this timer is set to zero. After
each hour of operation, the timer is incremented. The exception is
that during the "random timeout" as described in the SAFETY
SHUTDOWN MODE, the timer IS NOT incremented. The cleaning sequence
listed below can be initiated if the Ice (on)-Off-Clean toggle
switch is placed in the "Clean" position. A clean sequence can also
be initiated automatically. When the Clean Timer reaches 50 hours,
the unit will stop making ice and go through a clean sequence as
described below, and goes back to ice making. The Clean Timer is
reset to zero. If a clean cycle is manually initiated by the toggle
switch, the Clean Timer is also reset to zero.
[0091] During the clean mode, the yellow LED, CLEAN, on the control
board is illuminated. The water sensor switch will open and close
during a clean sequence; this is normal and should be ignored by
the control. The time periods and component operation during a
clean cycle are provided by Table 1. TABLE-US-00001 TABLE 1 Water
Time Evaporator Dump Refrigeration (Minutes) Gear Motor Solenoid
Compressor Comments 0.00-0.75 Off On Off Dump 0.76-10.00 On* Off
Off Wash (add cleaner) 10.01-10.75 On On Off Dump 10.76-12.75 On
Off Off Rinse 12.76-13.50 On Off Off Dump 13.51-15.50 On Off Off
Rinse 15.51-16.25 On On Off Dump 16.26-18.25 On Off Off Rinse
18.26-19.00 On On Off Dump 19.01-21.00 On Off Off Rinse *Gear motor
will not turn on until the water level switch is closed.
[0092] If the toggle switch is switched from "Clean" to "Off" or
"Ice"(on) prior to the completion of the initial 0.75-minute dump
cycle, the "Clean" sequence will abort. After the initial
0.75-minute dump cycle, if the toggle switch is turned to the "Off"
position, the unit stops, and when the switch is turned to another
position, the unit will resume and completes the clean sequence. If
the unit is turned back to the "Clean" position, the unit stops
after the sequence is complete. After the initial 0.75-minute dump
cycle, if the toggle switch is turned to the "On" position, the
unit completes the cleaning sequence and goes to a startup sequence
and starts making ice. If the toggle switch is turned to "Off"
within the first 15 seconds of being turned to "Clean", then the
cleaning sequence will be cancelled.
[0093] The unit ice making machine 10 goes into a safety shutdown
mode if any of the following occur: [0094] A. The water sensor
switch is open for 20 continuous seconds or more while the unit is
in the normal operating sequence mode: [0095] 1. If the control
senses open water-sensing switch for more than 20 seconds during a
normal freezes cycle, the unit goes into a safety shutdown mode.
[0096] 2. In the shutdown mode, the compressor/fan motor and the
gear motor are de-energized immediately. [0097] 3. It must remain
off for five minutes no matter the position of water sensing
switch. [0098] 4. During the five-minute shutdown period, the LED
for WATER OK flashes. [0099] 5. After the 5-minute shutdown period
and the water-sensing switch is closed, the control initiates
startup sequence as outlined in the sequence of operation. [0100]
Or [0101] B. The Hall-Effect Switch (HES)#1 fails to open and
re-close at least once during the first eight minutes of operation
after start-up or re-start. [0102] Or [0103] C. The HES#1 fails to
open and re-close at least once during any activity window, after
the initial eight minute startup period, when the unit is in a
normal operating mode: [0104] 1. The unit goes into a safety
shutdown mode. [0105] 2. In the shutdown mode, the compressor/fan
motor and the gear motor are de-energized immediately. [0106] 3.
The control times out for a period of {8 +random [0, 52]} minutes
then tries the restart sequence. In other words, the time out
period is equal to 8 minutes plus a random number between 0 and 52
minutes. [0107] 4. During the timeout period the LED for HES#1
flashes if it is active; else, it will not illuminate. [0108] 5.
During the restart sequence, the dump valve is energized for 30
seconds, the evaporator gear motor is energized, and the control
waits for the water-sensing switch to be closed before energizing
the compressor and fan motor contactor. [0109] 6. If safety
condition is still detected, the control generates another random
timeout period then tries the restart sequence again. [0110] 7.
These random restarts will occur until one of the following: [0111]
a. a total of 300 minutes from the first safety shutdown has
elapsed and no successful restart has been achieved. At that time
the unit will turn off and will require manual intervention to
restart. [0112] b. Within the 300 minutes a successful restart (10
minutes of normal ice-making) is registered. With this event, the
elapsed clock is reset to zero. [0113] 8. When the unit turns off
due to 7a, the LED for HES#1 flashes until the toggle switch is
toggled to "Off" and back to "Ice"(on). [0114] 9. If the control is
reset in this manner, the board will flash the problem related
LED's if the switch is turned to the "Off" position at anytime
during the first 48 hours after the reset occurred, after which
time the reset is erased from the memory.
[0115] During bin full mode, when the ice chute is full and the bin
can not accept any more ice, the second sensor element 76b opens
and the unit shuts down immediately. After a 5 minute time delay,
the unit checks for "full bin" status prior to progressing to the
"Restart" mode.
[0116] During the off mode, the unit is idle. This mode is entered
when the ice-off-clean selector switch is in the "Off"
position.
[0117] In another embodiment of the present invention, the ice
storage area is a device for dispensing ice, such as a medical
dispenser, which is able to be used in sanitary applications, such
as medical applications in hospitals or the like. More
specifically, the medical dispenser is positioned below the ice
making machine 10 and is generally sealed from the atmosphere to
prevent contamination of the ice located within. The medical
dispenser includes an inlet connected to the storage bin inlet tube
53 to receive ice pieces 38 from the ice making machine 10. The ice
pieces are then stored within a body portion of the medical
dispenser, which is preferably a one-piece component made of food
grade plastic.
[0118] Additionally, the medical dispenser includes an outlet
formed in the body and a dispensing device coupled with the outlet
to automatically dispense ice when indicated by a user. For
example, the dispensing device may include a sensor for detecting
the presence of a user's drinking cup (or any other container
utilized by the user) or an actuating arm that is to be actuated by
the user's drinking cup. The sensor or the actuating arm will then
send a signal (mechanical or electrical) to an agitator located
within the body of the medical dispenser. The agitator then rotates
and forces ice pieces out of the dispensing device and into the
user's drinking cup. The dispensing device may also include a
pivoting door that prevents ice from exiting the body of the
medical dispenser until indicated by a user. Any other suitable ice
storage and/or ice dispensing device may be used with the present
invention. The dispensing device may also include a blue LED light
to indicate that the ice making machine 10 is on and to illuminate
the front of the medical dispenser unit for a user.
[0119] Referring back to FIG. 10, the auger 30 and the casing 24 of
the ice forming apparatus 12 will now be discussed in more detail.
A water seal 160, a C-clip 162, a bearing bush 164 and the upper
bearing 43 are received by an upper shaft portion 172 of the auger
30 and are positioned above the ice cutting head 37 to form a
watertight seal between the auger upper shaft portion 172 and the
ice cutting head 37 while permitting relative movement between the
respective components 30, 37. Similarly, the lower bearing 43, a
bearing bush 166, a C-clip 168, and a shaft seal 170 are received
by an upper shaft portion 172 of the auger 30 and are positioned
below the ice cutting head 37 to form a second seal and permit
relative movement between the respective components 30, 37.
Additionally, a run-on ring 174 and an O-ring 176 are received by a
lower shaft portion 178 of the auger 30 to form a watertight seal
between the auger 30 and the casing 24 and to prevent water from
leaking into the auger motor 33. The auger lower shaft portion 178
also includes a key slot 182 that receives a feather key 180 to be
coupled with the auger motor 33. For example, the lower shaft
portion 178 is received within a rotatable sleeve (not shown) of
the auger motor 33 and the feather key 180 is received within a
slot in the sleeve to rotate the auger 30 when the auger motor 33
is activated.
[0120] The above components are received within the casing 24 and
are further secured therewith by a water seal 184, a C-clip 186, a
roller bearing 188, a shim ring 190, and a second C-clip 192. More
specifically, the water seal 184 cooperates with the run-on ring
174 to form the lower seal between the auger 30 and the casing 24.
Additionally, the roller bearing 188 permits relative movement
between the auger 30 and the casing 24 during rotation of the motor
sleeve. Additionally, a plurality of screws 194 are received within
openings 195 in the casing and secured to the ice cutting head 37
via threaded openings 196 to prevent rotation of the ice cutting
head 37 with respect to the casing 24.
[0121] The ice making chamber 20 is preferably manufactured by
Ziegra, which is located in Isernhagen, Germany, and is
commercially available as model numbers ZNE125, ZNE200, ZNE300,
ZNE400, ZNE500, ZNE1000, ZNE200FE, ZNE300FE, ZNE400FE, ZNE500FE,
and ZNE1000FE, where the number in each model number indicates the
capacity of the ice making chamber 20 in kilograms per hour and the
designation "FE" indicates that flaked ice is made (no designation
means that nugget ice is made). The auger drive gear system 35 is
preferably a gear system that prevents the auger motor 33 from
undesirably operating in the reverse direction due to loads present
on the auger 30 during system startup. The water level sensor 102
is preferably a Gems type LS-3 water level sensor manufactured by
Gems Sensors, which is located in Plainville, Conn.
[0122] The above described embodiment provides a low cost, simple
design and method for detecting the migration of the ice pieces
through the transfer zone and for detecting the build-up of the ice
pieces in the transfer zone. Furthermore, the above described
embodiment provides an improved ice sensing apparatus by
substantially separating a portion of the apparatus from the clean
zone and the naturally-occurring moisture located therein.
[0123] While the invention has been described in connection with an
auger-type ice machine, it can also be used with other types of
machines, such as cube-type machines, nugget-type machines, or
medical dispenser machines.
[0124] It is therefore intended that the foregoing detailed
description be regarded as illustrative rather than limiting, and
that it be understood that it is the following claims, including
all equivalents, that are intended to define the spirit and scope
of this invention.
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