Making ice in a refrigerator

An icemaker for a refrigerator having a stationary tray with plural curved-bottom cavities for molding crescent ice. An electrical heater melts the ice surface of the tray bottom to permit freeze embedded ejector tine of a rotary harvesting means to sweep the crescent ice from the tray. A stationary stripper cam surface forces the ice radially from the ejector tine which has wedging surfaces thereon to facilitate fracture of the ice for harvesting into half-crescent sections.

CROSS-REFERENCE TO RELATED APPLICATION 
The present invention is related to the subject matter described in 
co-pending application Ser. No. 258,308 filed Oct. 17, 1988, in the name 
of Frank Karlovits entitled "Making Ice In A Refrigerator" and assigned to 
the assignee of the present invention. 
BACKGROUND OF THE INVENTION 
The present invention relates to devices for molding and harvesting formed 
ice in a refrigerator for use in cooling beverages and particularly in 
cooling beverages in individual drinking containers. In providing 
icemakers for household refrigerators, it is known to form ice in a 
stationary tray having individual compartments with a curved bottom to 
provide the formed ice with a generally crescent-shaped configuration. 
Crescent-shaped ice is typically harvested by heating the tray an amount 
sufficient to cause a slight amount of melting at the tray/ice interface 
to enable the crescent ice to be swept from the curved bottom cavity by a 
rotating comb. 
In the above-referenced Karlovits application, such a rotary melt-out 
icemaker for harvesting crescent ice has been described wherein an arm or 
tine of the comb is immersed in the waterfill in the cavity or mold and 
embedded in ice frozen therein to enable harvesting by rotating the 
embedded comb for sweeping the crescent ice from the cavity. As the 
crescent ice is swept out of the cavity the level surface of the ice 
contacts stationary ejectors to cause stripping of the ice from the tine 
and simultaneous fracturing to thereby provide two half-crescent or 
quarter-round ice shapes from a single crescent-shaped ice formation. 
However, in providing the simultaneous stripping and fracturing of the 
crescent ice from the rotating harvesting tine by cam action of the 
crescent ice against the stationary ejector or stripper, problems have 
been encountered in providing the optimization of stripping and fracturing 
by pressing the ice against the stationary stripper as the tines of the 
comb are rotated during the harvesting cycle. In particular, difficulty 
has been encountered in causing the crescent ice to fracture as it is 
radially stripped from the rotating harvesting tine, inasmuch as the 
forces of the camming surface of the stripper tend to move the ice in a 
radial direction from the rotating tine; and in some instances, 
insufficient forces have been provided to cause fracturing and splitting 
of the crescent into the half-crescent shape. 
Accordingly, it has been desired to provide a way or means of ensuring that 
harvested crescent ice in a refrigerator icemaker is split or fractured 
into two half-crescent sections as it is harvested from the mechanism for 
providing the optimum configuration for iced beverages in individual 
glasses or cups. 
SUMMARY OF THE INVENTION 
The present invention provides an icemaker for a household refrigerator 
having a stationary ice forming tray provided with a plurality of curved 
bottom compartments and a heater for melting the ice/tray interface to 
enable rotary sweep harvesting of the individual crescent ice from the 
mold cavities. Harvesting comb tines are immersed in the cavity water fill 
and frozen embedded in the crescent ice. Upon energization of the tray 
heater, melt-out occurs at the ice/tray interface along the curved bottom 
and partition sides thereby permitting rotation of the harvesting comb to 
sweep the ice from the mold cavity. Stripping and splitting of the ice 
from the comb into two half-crescent sections from each molded ice 
crescent occurs as the crescent ice contacts a camming surface on 
stationary strippers. 
The present invention provides a unique tapered or wedge shape to the 
harvesting comb tines to effect a splitting action to the crescent ice to 
augment and facilitate fracture of the crescent-shaped ice into two 
half-crescent sections simultaneously as the ice is radially stripped from 
the harvesting tines. The present invention thus ensures simultaneous 
fracturing and splitting of crescent ice during stripping of the ice from 
the harvesting comb.

DETAILED DESCRIPTION 
Referring to FIG. 1, the icemaker assembly is indicated generally at 10 and 
has a stationary tray 12 preferably formed of a light metal such as 
aluminum or other material having a high coefficient of thermal 
conductivity and has formed therein a plurality of curved bottom ice 
forming cavities one of which is indicated by reference numeral 14. Tray 
12 has a generally U-shaped groove provided in the bottom thereof in which 
is pressed an electrical resistance heater having a generally U-shaped 
configuration, one leg of which is denoted by reference numeral 16 in FIG. 
1. The curved bottom ice cavity is separated from the adjacent cavity by a 
partition or side wall 18 which has a suitable weir 20 formed therein to 
permit water fill to flow between adjacent cavities for complete filling 
of the tray. Water fill is provided by a suitable electrically operated 
valve 22 which is actuated by a solenoid 24 which has electrical leads 26, 
28 adapted for attachment to an electrical programmer (not shown). The 
valve has an inlet 30 adapted for connection to a source of water and an 
outlet 32 positioned to discharge water into the tray cavity adjacent the 
valve. In the presently preferred practice the valve 22 is disposed at the 
end of the tray opposite that shown in the foreground in FIG. 1. 
A harvesting means, indicated generally at 34, is disposed immediately 
above the center of the row of ice cavities, such as the cavity 14 and 
includes a shaft 36 disposed above the tray and oriented generally 
longitudinally with the length of the tray and journalled in suitable 
supports (not shown) for rotation with respect thereto. One end of the 
shaft 36 has drive engaging surfaces shown as a pair of flats 38, 40 which 
engage a suitable speed reducer driving mechanism 42 disposed on the near 
end of the tray as shown in FIG. 1. Speed reducer 42 is driven by a 
suitable timing motor 44 with leads 46, 48 adapted for connection to a 
source of power as, for example, a thermostatic switch (not shown) 
connected to a power line. 
Shaft 36 has mounted thereon at a longitudinal station corresponding to 
each of the ice forming cavities such as cavity 14 a member having a 
plurality of arms or tines one of which comprises an ejector indicated 
generally by the reference numeral 50. At least one and preferably two 
auxiliary tines 52, 54 are provided in accurately spaced arrangement with 
respect to the ejector tine 50, with the tines 50, 52 and 54 being 
preferably disposed in equally spaced arrangement. 
The ejector tine 50 beginning at its root adjacent shaft 36, tapers 
outwardly to have its greatest transverse width, e.g. width in a direction 
at right angles to the radius thereof, located radially at approximately 
four-fifths (4/5ths) of its length and the tine 50 tapers from its maximum 
width in a converging manner to an apex at its radial extremity with the 
plane of the taper generally at right angles to the axis of rotation of 
shaft 36. 
The outwardly tapering sides of the ejector tine 50 are denoted by 
reference numerals 56, 58 in FIG. 1; and, the converging surfaces denoted 
by the reference numerals 60, 62 in FIG. 1. 
Referring to FIGS. 1 and 2, each of the curved bottom mold cavities, such 
as cavity 14, has a stationary stripper 64 disposed thereabove and has the 
upper surface thereof formed in a generally constant radius curvature in a 
region around shaft 36 with the remaining portion of the upper surface 66 
disposed to the right of shaft 36 in the drawings, formed as a camming 
surface to provide a radially outwardly stripping action as will 
hereinafter be discussed. 
In operation, solenoid 24 is energized by a suitable program switch (not 
shown) and the tray 12 has its mold cavities filled to the desired water 
level indicated by reference numeral 68 whereupon the power to the 
solenoid is terminated and valve 22 closes. The harvesting means 34 is 
positioned such that the ejector tine 50 is disposed vertically downward 
into the water fill as shown in solid outline in FIG. 1. 
The water fill in the mold cavity is then permitted to freeze forming 
crescent ice in each of the cavities having the curved bottom 14. Upon 
thermostatic detection by any convenient means (not shown) that the water 
fill in tray 12 has frozen, the electrical heater 16 is energized by a 
suitable electrical switch (not shown) and motor 44 is simultaneously 
energized. However, in view of the friction forces of the ice against the 
curved bottom 14 of each cavity, the motor is stalled and harvesting means 
34 is unable to rotate. However, upon the heater 16 raising the tray 
temperature to a point whereupon surface melting occurs along the curved 
bottom of each cavity, the ejector tine 50 begins to rotate in a clockwise 
direction. When the harvesting means has rotated from the position shown 
in FIG. 1 through a central angle of approximately 135 degrees to the 
position shown in FIG. 2, the formed crescent ice 70 is in the position 
shown in FIG. 2 whereupon the straight surface 72 of the crescent ice has 
just made contact with the cam surface 66 of the stripper 64. 
Referring to FIG. 3, continued clockwise rotation of the shaft 36 from the 
position of FIG. 2 through a central angle of approximately 45 degrees, to 
the position shown in FIG. 3, causes the cam surface 66 to force the 
crescent ice radially outwardly along the ejector 50 whereupon the edges 
56, 58 have caused fracture of the crescent ice into two half sections 71, 
73 as shown in solid outline in FIG. 3. 
Referring to FIG. 4, continued clockwise rotation of the shaft 36 from the 
position shown in FIG. 3, through a central angle of approximately 45 
degrees to the position shown in FIG. 4 causes the half-crescent ice 
section 73 to be ejected from the strippers to fall into a receptacle (not 
shown). The second half-crescent portion of ice 71 falls upon the 
auxiliary harvesting arm or tine 54 which prevents the section 71 from 
falling back into the tray cavity. 
Referring to FIG. 5, continued clockwise rotation of the shaft 36 from the 
position shown in FIG. 4 through a central angle of approximately 60 
degrees causes the auxiliary arm or tine 54 to eject the remaining half 
crescent ice section 71 from the strippers 64 and thus completes the 
harvesting of the ice. Upon return of the ejector tine 50 to the position 
shown in FIG. 1, the icemaker is in condition for refilling of the tray 
with water and start of another freezing cycle. 
Referring to FIGS. 6 and 7, the ejector arm or tine 50 preferably has 
undercuts, indicated by reference numerals 74, 76 in FIGS. 6 and 7 
provided along opposite faces thereof and these are inclined in the radial 
direction to facilitate fracture of the ice during radial movement along 
the ejector arm 50. 
Referring to FIGS. 8 through 10, an alternate form of the harvesting means 
is illustrated at 134 as having a plurality of arms or tines 150, 152, 155 
rotatable shaft 136. The ejector tine indicated generally by reference 
numeral 150 has a radially curved or scimitar-shaped configuration as 
shown in FIG. 8 and is circumferentially equally spaced with a pair of 
auxiliary arms 152, 154. With reference to FIG. 9, a typical cross-section 
of the auxiliary arms is illustrated for arm 152 and has a 
rectangular-shape in tranverse section with the elongated side of the 
rectangle inclined at an angle to the axis of the shaft 136 to thereby 
provide an inclination or axial pitch to the auxiliary arms shown 
typically in FIG. 9. The inclination to the arms 152, 154 facilitates 
circulation of cold air above the tray for freezing. 
Referring to FIG. 10, the ejector tine 150 is shown in transverse section 
as having inclined undercuts 153, 155 provided on opposite faces thereof 
to facilitate fracture of the crescent ice. It will be understood that the 
undercuts 153, 155 are similar to the undercuts 74, 76 of FIGS. 6 and 7. 
The invention thus provides melt-out rotary icemaker having an ejector tine 
of the rotary harvesting means embedded in the crescent ice. The sides of 
the ejector tine have a reverse taper to provide a wedging action during 
stripping to facilitate fracture and splitting of the molded crescent ice 
formed in each mold cavity into two half-crescent sections. 
Although the invention has hereinabove been described with respect to the 
illustrated embodiments, it will be understood that the invention is 
capable of modification and variation and is limited only by the following 
claims.