Ice removal device for use in an ice maker and method for controlling same

An ice removal device for use in an ice maker comprises a driving motor; a cam gear; a cam provided with a smaller and a larger circular portions with concentrical circumferential surfaces, respectively; a plurality of gears; and a rotation reversing sensor having a knob switch. The rotation reversing sensor is disposed adjacent to the cam in such a way that the knob switch is pressed by either one of edges of the circumferential surface of the larger circular portion of the cam at a time.

FIELD OF THE INVENTION 
The present invention relates to an ice maker; and, more particularly, to 
an ice removal device for use in the ice maker having a reduced number of 
components and a method for controlling same. 
DESCRIPTION OF THE PRIOR ART 
As shown in FIG. 1A, an ice maker for use in a refrigerator normally 
comprises an ice manufacturing unit 20, a temperature sensor 21 for 
sensing the temperature of the ice manufacturing unit 20, a driving motor 
10 for rotating the unit 20, a rotation reversing switch 22 for changing 
the rotational direction of the driving motor 10, an ice box 30 for 
receiving ice cubes falling from the unit 20, a sensor 33 provided with a 
sensing member 34 for detecting whether or not the ice box 30 is fully 
filled, a water tank 40, a water reservoir 42, a water supplying hose 44, 
and a pumping motor 41. 
The pumping motor 41 supplies water from the water reservoir 42 to the ice 
manufacturing unit 20 through the water supplying hose 44. 
There is shown in FIG. 1B a perspective view of the ice manufacturing unit 
20 and a supporting member 25. The unit 20 and the supporting member 25 
are provided with a protrusion 27 and a restrainer 26, respectively, in 
such a way that the rotation of the protrusion 27, and hence the unit 20 
is limited by the restrainer 26. 
There is shown in FIG. 2A a conventional ice removal device for use in the 
automatic ice maker. The conventional ice removal device 100 includes a 
driving motor 10, a plurality of (e.g., five) gears 11 to 15, a cam gear 
60, a cam 50 having an upper and a lower faces 51, 52 and a 
circumferential surface 53, a pair of stoppers 61, a normal position 
sensor 23 having a knob, a rotation reversing switch 22 having a knob, an 
actuator 70, and a base 90. 
The driving motor 10 rotates the cam gear 60 through the plurality of gears 
11 to 15 either clockwise or counterclockwise. 
The cam gear 60 and the cam 50 are, in turn, secured on one end of the 
shaft 20' of the ice manufacturing unit 20 (see FIG. 2B), so that they can 
rotate integrally in response to the rotation of the driving motor 10. 
The pair of stoppers 61 protruding from the base 90 and facing each other 
are spaced out by a desired distance from the circumferential surface 53 
of the cam 50. 
The actuator 70 includes a pair of wings 71, 72 resiliently coupled 
together via a spring member (not shown), one wing 71 disposed between the 
pair of stoppers 61 in such a way that one end thereof optionally contacts 
with either one of the edges of the upper face 51 of the cam 50 at a time 
and the other wing 72 disposed to press the knob of the rotation reversing 
switch 22. The remaining ends of the wings 71, 72 are held by a shaft 73 
so that the pair of wings 71, 72 extend in opposite directions from each 
other. 
The normal position sensor 23 is so disposed that the knob thereof is 
pressed by the circumferential surface of the lower face 52 of the cam 50. 
FIG. 2B is a cross sectional view taken along a line I--I of FIG. 2A, 
showing the upper and the lower faces 51, 52 of the cam 50 in detail. 
There is shown in FIG. 3 another conventional ice removal device 200. Such 
an ice removal device 200 is similar to the above-mentioned device 100 
except for the shape of a cam 150 and an actuator 170 used therein. 
The cam 150 is provided with a smaller circular portion 151 and a larger 
circular portion 152, the larger circular portion 152 having a pair of 
contact faces 161. 
The actuator 170 includes a pair of wings 171, 172 resiliently coupled 
together via a spring member (not shown), one wing 171 disposed between 
the pair of contact faces 161 in such a way that one end thereof 
optionally contacts with either one of the pair of contact faces 161 of 
the cam 150 at a time and the other wing 172 disposed so that one end 
thereof may press the knob of the rotation reversing switch 22. The 
remaining ends of the wings 171, 172 are held by a shaft 173 so that the 
pair of wings 171, 172 extend in opposite directions from each other. 
Furthermore, a pair of protrusions (not shown) formed on the bottom 
surfaces of the wings 171, 172 are fitted into a pair of the guide slots 
174, 175 formed on the base 190, respectively. The movement of the wings 
171, 172 are, therefore, restricted by the guide slots 174, 175, 
respectively. 
Such conventional ice removal devices 100, 200 include many components, 
resulting in a poor productivity at an increased manufacturing cost. 
Furthermore, since the rotation of the driving motor, and hence the ice 
manufacturing unit, is controlled through the actuator, the operating 
process thereof and the configuration of the cam are complicated, thereby 
increasing the possibility of malfunctioning thereof. 
SUMMARY OF THE INVENTION 
It is, therefore, a primary object of the present invention to provide an 
improved ice removal device for use in an ice maker having a reduced 
number of components, thereby facilitating the assembly thereof and 
reducing the likelihood of malfunctioning, and a method for controlling 
thereof. 
In accordance with one aspect of the present invention, there is provided 
an ice removal device for use in an ice maker having a controller and an 
ice manufacturing unit with a shaft, the device comprising: a driving 
motor; a cam gear secured on one end of the shaft of the unit; a plurality 
of gears for transmitting the rotational force of the driving motor to the 
cam gear; a cam secured on the end of the shaft of the unit in such a way 
that the cam gear is interposed therebetween, the cam provided with a 
smaller and a larger circular portions with concentrical circumferential 
surfaces, respectively, the circumferential surface of the larger circular 
portion having a pair of edges; and a rotation reversing sensor having a 
knob switch, the sensor disposed adjacent to the cam in such a way that 
the knob switch is optionally pressed by either one of the edges of the 
circumferential surface of the larger circular portion of the cam at a 
time. 
In accordance with another aspect of the present invention, there is 
provided a method for controlling an ice removal device for use in an ice 
maker having a controller and an ice manufacturing unit with a shaft, the 
ice removal device including a driving motor, a cam gear and a cam secured 
on the shaft of the ice manufacturing unit, a plurality of gears for 
transmitting the rotational force of the driving motor to the cam gear, 
and a rotation reversing sensor having a knob switch, the method 
comprising the steps of: 
A. rotating the cam and the ice manufacturing unit in a first direction; 
B. checking whether or not the rotation reversing sensor is activated, 
wherein, if the sensor is determined to be activated, step B proceeds to 
step C, but if not, returns to step A; 
C. rotating the cam and the ice manufacturing unit in a second direction; 
D. checking whether or not the rotation reversing sensor is deactivated, 
wherein, if the sensor is determined to be deactivated, step D proceeds to 
step E, but if not, returns to step C; 
E. continuously rotating the cam and the ice manufacturing unit in the 
second direction; 
F. checking whether or not the rotation reversing sensor is activated, 
wherein, if the sensor is determined to be activated, step F proceeds to 
step G, but if not, returns to step E; 
G. rotating the cam and the ice manufacturing unit in the first direction; 
H. checking whether or not the rotation reversing sensor is deactivated, 
wherein, if the sensor is determined to be deactivated, step H proceeds to 
step I, but if not, returns to step G; and 
I. stopping the driving motor after a predetermined time has elapsed.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
There is shown in FIG. 4 a schematic view of a preferred embodiment of an 
inventive ice removal device 400 for use in an automatic ice maker having 
a controller (not shown), e.g., a micro computer, an ice manufacturing 
unit 20 with a shaft 20' and a supporting member 25 (see FIGS. 1A and 1B). 
The inventive ice removal device 400 includes a driving motor 410, a cam 
gear 460, a plurality of (e.g., five) gears, 411 to 415, a cam 450, and a 
rotation reversing sensor 430 having a knob switch 431. 
The plurality of gears, 411 to 415, are arranged between the driving motor 
410 and the cam gear 460 in such a way that the first and the last gears 
411, 415 are engaged with the driving motor 410 and the cam gear 460, 
respectively, thereby transmitting the rotational force of the driving 
motor 410 to the cam gear 460. 
The cam 450 is provided with a smaller and a larger circular portions 451 
and 452 with concentrical circumferential surfaces 453 and 454, 
respectively. The circumferential surface 454 has a pair of edges, and an 
opening angle .THETA. thereof (see FIG. 5A) is preferably less than or 
equal to 202 degrees. 
The cam gear 460 and the cam 450 are, in turn, secured on one end of the 
shaft 20' of the ice manufacturing unit 20 so that they rotate integrally 
in response to the rotation of the driving motor 410. 
The rotation reversing sensor 430 is disposed adjacent to the cam 450 in 
such a way that the knob switch 431 is optionally pressed by either one of 
the edges of the circumferential surface 454 of the larger circular 
portion 452 of the cam 450 at a time. 
The controller incorporated in the ice maker receives a series of signals 
from the sensor 430 and controls the rotation of the driving motor 410. 
With reference to FIGS. 5A to 5D, operation of the cam 450 and the rotation 
reversing sensor 430 of the ice removal device of the present invention 
will now be described. 
FIG. 5A represents an initial position of the cam 450 with respect to the 
rotation reversing sensor 430. 
In the ice maker, when an ice manufacturing process is completed, the 
controller starts to integrally rotate the cam 450 and the ice 
manufacturing unit 20 clockwise by rotating the driving motor 410 in one 
direction, e.g., clockwise. 
As shown in FIG. 5B, when the cam 450 and the ice manufacturing unit 20 
rotate clockwise by a predetermined angle, e.g., 125 degrees, a protrusion 
27 of the ice manufacturing unit 20 is stopped by a restrainer 26 of the 
supporting member 25, as mentioned before, and the ice manufacturing unit 
cannot rotate any further. Therefore, when the cam 450 is forced to 
further rotate, the ice manufacturing unit 20 is subjected to a 
distortion, making the ice cubes therein fall into an ice box 30 disposed 
below the ice manufacturing unit 20 (see FIG. 1A). 
If the cam 450 is forced to further rotate clockwise by, e.g., 25 degrees, 
and if one edge of the circumferential surface 454 of the larger circular 
portion 452 of the cam 450 comes to press the knob switch 431 of the 
rotation reversing sensor 430, as shown in FIG. 5C, the controller 
reverses the rotational direction of the driving motor 410, which, in 
turn, will start to rotate the cam 450 and the ice manufacturing unit 20 
counterclockwise. As soon as the cam 450 begins to rotate 
counterclockwise, the knob switch 431 will be released, while the driving 
motor 410 continues to rotate in the reversed direction. 
As shown in FIG. 5D, if the other edge of the larger circular portion 452 
of the cam 450 presses the knob switch 431 of the rotation reversing 
sensor 430, the controller reverses the rotational direction of the 
driving motor 410 again, rotating the cam 450 and the ice manufacturing 
unit 20 clockwise. The controller then stops the driving motor 410 after a 
further rotation by a predetermined degree, e.g., 8 degrees, or when the 
cam 450 and the ice manufacturing unit 20 are restored to the initial 
position. 
Such an ice removal device 400 in accordance with the present invention can 
be assembled more easily than a conventional one owing to a reduced number 
of components therein, and decrease the possibility of malfunctioning 
thereof. 
There are shown in FIGS. 6A and 6B flow charts illustrating a process for 
controlling the ice removal device 400 in accordance with the present 
invention. 
In step 1 of the controlling process, when an ice manufacturing process is 
completed, the controller rotates the driving motor 410 in one direction, 
e.g., clockwise, in order to rotate the cam 450 and the ice manufacturing 
unit 20 clockwise. 
At step 2, the controller checks whether or not the rotation reversing 
sensor 430 is activated. The rotation reversing sensor 430 is activated by 
one edge of the circumferential surface 454 of the larger circular portion 
of the cam 450 pressing the knob switch 431 thereof, as shown in FIG. 5C. 
If it is determined that the sensor 430 is activated, the process proceeds 
to step 3, wherein the controller rotates the cam 450 and the ice 
manufacturing unit 20 counterclockwise by reversing the rotational 
direction of the driving motor 410. In step 4, the controller checks 
whether or not the rotation reversing sensor 430 is deactivated, i.e., 
checks whether or not the knob switch 431 thereof is released. If the 
sensor 430 is determined to be deactivated, the process proceeds to step 
5, wherein the controller continues to rotate the cam 450 and the ice 
manufacturing unit 20, but if not, returns to step 3. 
In step 6, the controller checks again whether or not the rotation 
reversing sensor 430 is activated. As shown in FIG. 5D, the sensor 430 is 
activated by the other edge of the larger circular portion 452 of the cam 
450 pressing the knob switch 431 thereof. If the rotation reversing sensor 
430 is determined to be activated, the process proceeds to step 7, wherein 
the controller rotates the cam 450 and the ice manufacturing unit 20 
clockwise again by reversing the rotational direction of the driving motor 
410. If not, however, the process returns to step 5. 
Finally, the process proceeds to step 8, wherein the controller checks 
whether or not the sensor 430 is deactivated. If the rotation reversing 
sensor 430 is determined to be deactivated, the process goes to step 9, 
wherein the controller stops the driving motor 410 after a predetermined 
time, e.g., 0.2 second, has elapsed. However, if not, the process returns 
to step 7. 
On the other hand, if the automatic ice maker is re-energized after an 
electric power thereto has been cut-off, the ice manufacturing unit 20 
must be reset in the initial position. Therefore, as shown in FIG. 6B, it 
is preferable to first check whether or not the ice maker is re-energized 
step 10) prior to step 1. If it is determined that the ice maker has been 
re-energized, the process proceeds to step 11 to reset the unit 20, but if 
not, the process proceeds to step 1 and performs the ice removing process 
shown in FIG. 6A. 
In step 11, the controller checks whether or not the rotation reversing 
sensor 430 is activated, and if the sensor 430 is determined to be 
activated, the process goes to step 17, but if not, the process proceeds 
to step 12, wherein the controller rotates the cam 450 counterclockwise by 
rotating the driving motor 410 in another direction, e.g., 
counterclockwise. 
In step 13, the controller checks again whether or not the rotation 
reversing sensor 430 is activated. If the sensor 430 is determined to be 
activated, the process proceeds to step 14, but if not, the process 
returns to step 12. 
In step 14, the controller rotates the cam 450 clockwise by reversing the 
rotational direction of the driving motor 410. At step 15, the controller 
checks whether or not the rotation reversing sensor 430 is deactivated. If 
the sensor 430 is determined to be deactivated, the process goes to step 
16 and the controller stops the driving motor 410 after a predetermined 
time, e.g., 0.2 second has elapsed, but if not, the process returns to 
step 14. Then, the process proceeds to step 1 and performs the ice 
removing process S1 to S9. 
On the other hand, in step 17, the controller rotates the cam 450 clockwise 
by rotating the driving motor 410 clockwise. In step 18, the controller 
checks whether or not the rotation reversing sensor 430 is deactivated. If 
the sensor 430 is determined to be deactivated, the process returns to 
step 16, but if not, the process proceeds to step 19, wherein the 
controller checks whether or not a predetermined time, e.g., 2 seconds, 
has elapsed after, in step 17, the cam 450 began to rotate clockwise. In 
step 19, if it is determined that the predetermined time has elapsed, the 
process proceeds to step 20, but if not, returns to step 17. 
In step 20, the controller rotates the cam 450 counterclockwise by 
reversing the rotational direction of the driving motor 410. In step 21, 
the controller checks whether or not the sensor 430 is deactivated, and if 
the sensor 430 is determined to be deactivated, the process proceeds to 
step 16, but if not, returns to step 20. 
Although the invention has been shown and described with respect to the 
preferred embodiments, it will be understood by those skilled in the art 
that various changes and modifications may be made without departing from 
the spirit and scope of the invention as defined in the following claims.