System for making frozen food article

System for making frozen food article comprises a refrigeration source of high capacity, a food-freezing chamber normally maintained at ambient temperature and of low thermal capacity, a source of food or vegetable juice or puree for freezing, and a controller. The controller controls the refrigeration source to maintain an adequate supply of chilled coolant, controls the discharge of the coolant liquid to a coolant jacket around the frozen food chamber for rapid chilling, controls the discharge of food material to the chamber, controls the beating of the food material while it is freezing, and finally controls the discharge of the resultant beaten frozen food article into a receiving cup.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention is directed to a system for making a frozen food article and 
particularly a system which is sufficiently completely automated that no 
operator skills are required, and it is adaptable to coin operation. 
2. Brief Description of the Prior Art 
The conventional freezing device comprises a compressor for compressing a 
refrigerant gas which is then condensed into a liquid which is expanded to 
a lower pressure so that it evaporates taking up heat to cause 
refrigeration. The expanding refrigerant is usually in direct thermal 
communication with the material to be chilled so that cooling rate of the 
material to be chilled is limited by the steady state operation of the 
compressor. In some cases, a coolant is cooled by the expanding 
refrigerant gas. Submerged in the cooled liquid are containers which 
contain food material which is to be frozen. Spreen U.S. Pat. No. 
1,764,653 shows a structure of this nature. In O'Neil U.S. Pat. No. 
2,058,098, the expanding refrigerant cools beverage liquid so that, upon 
demand, a cooled beverage can be dispensed. Palmer U.S. Pat. No. 3,041,852 
shows a compressor and evaporator which are contained in one unit and a 
separate container which receives the evaporating coolant to cool an 
article contained therein. This prior art is not directly pertinent, but 
it is generally directed to refrigeration systems for food materials. Ash 
U.S. Pat. No. 2,590,061 discloses a system wherein a fluid is maintained 
at a relatively constant temperature for dispensing to and cooling a 
remote vat, but this fluid is not recirculated back to the reservoir 
because the fluid is not a coolant. Bright U.S. Pat. No. 2,040,828 is 
similar to Ash, and its fermentation tank is substantially greater in 
volumetric capacity than the capacity of the cooling apparatus. 
Furthermore, while Haley U.S. Pat. No. 2,720,084 employs separate 
refrigeration for chilling a circulating coolant, the coolant is for 
air-conditioning service, and there is no teaching of a particular type of 
food-freezing chamber. 
SUMMARY OF THE INVENTION 
This invention is directed to a system for making a frozen food article, 
and particularly a system which includes a cooling system of high 
refrigeration capacity, a beating and mixing chamber of low thermal 
capacity, a food material supply, and a controller for controlling the 
various parts of the system so that a frozen food article is produced 
without requiring operator skills. 
It is thus an object of this invention to provide an integrated system 
whereby a frozen food article can be produced. It is another object to 
provide a system which is sufficiently automated that it can be arranged 
to be operated by a simple switch or by a coin acceptor so that a frozen 
food article can be obtained on demand. It is another object to provide a 
system for making a frozen food article which includes a refrigeration 
source of high thermal capacity and a food-freezing and beating chamber of 
low thermal capacity so that the chamber can be maintained at ambient 
until it is required for chilling and thereupon quickly cooled down, the 
cooling being achieved by demand and controlled by the control unit. 
The features of the present invention which are believed to be novel are 
set forth with particularity in the appended claims. The present 
invention, both as to its organization and manner of operation, and 
together with further objects and advantages thereof may be understood 
best by reference to the following description taken in connection with 
the accompanying drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Refrigeration for making the frozen food article is achieved by cooler 10. 
Compressor 12 is driven by motor 14 and draws refrigerant vapor from line 
16. It delivers high pressure refrigerant gas at line 18 to condenser 20. 
The high pressure refrigerant vapor is condensed to a liquid giving off 
heat. Fan 22 is driven by motor 14 and delivers air across condenser 20 so 
that the heat is rejected to the atmosphere. Refrigerant liquid is 
delivered by line 24 to expansion valve 26 which expands the high pressure 
liquid to low pressure causing evaporation in cooling coil 28. Suction 
line 16 is connected to cooling coil 28 so that the refrigerant is in the 
closed system. The usual freons provide a satisfactory system. 
Cooling coil 28 is in coolant tank 30. Coolant 32 substantially fills the 
tank and extends almost to the top thereof leaving a small air space at 
the top. The top of the tank is closed to minimize both thermal and 
evaporation losses. Insulation 34 surrounds coolant tank 30 to minimize 
thermal losses. The line from expansion valve 26 to cooling coil 28 and 
the suction line 16 from the bottom of cooling coil 28 to the suction of 
the compressor are both preferably insulated also to minimize thermal 
losses. Temperature sensor 36 senses the temperature of the coolant in the 
tank. 
Coolant-circulating pump 38 draws suction through line 40 and delivers 
circulating coolant at line 42. Three-way valve 44 can be operated to 
deliver to the coolant out through delivery line 46 or through 
recirculating line 48. In standby operation, valve 44 is directed so that 
recirculating line 48 receives the coolant pumped by pump 38. Refrigerator 
compressor 12, sensor 36, coolant pump 38, and control valve 44 are all 
connected to master control unit 50 which controls the cycling of the 
entire system. Coolant pump 38 is operated on a sufficient cycle to 
prevent stratification of coolant 32 in coolant tank 30 to keep the 
coolant pump, its lines and valve 44 cooled and thus ready to deliver 
coolant in delivery line 46 as required. 
The range of temperature suitable for coolant 32 in coolant tank 30 is from 
0 degrees F. to 25 degrees F. below zero. For these purposes, a coolant 
mixture of half ethylene glycol and half water is useful. Compressor 12 is 
cycled, and valve 26 is operated to maintain the desired temperature of 
coolant 32. For example, pressure operated expansion valve 26 would be 
satisfactory with temperature sensor 36 establishing the on-cycle of 
compressor 12. The temperature at line 40 could be sensed to control the 
cycling of pump 38, if desired. Coolant pump 38 is positioned exteriorly 
of coolant tank 30 to permit maintenance thereof, and it is preferably 
sufficiently low that gravitational priming of the pump is achieved. 
Furthermore, the pump, valve 44, and the associated lines are preferably 
insulated to minimize thermal loss. 
Freezer 52, shown in the system in FIG. 1 and shown in more detail in FIGS. 
2 and 3, has as its principal part tube 54 which defines freezing chamber 
56 in its interior. Surrounding chamber 56 is cooling jacket 58 which is 
connected to line 46 and contains coolant 32 when cycled. Return line 60 
returns coolant 32 to the interior of coolant tank 30. Bleed line 62 
bleeds the top of coolant jacket 58 back to tank 30 so that, when valve 44 
is opened in a direction to deliver coolant 32 up delivery line 46, the 
air which might otherwise be trapped in the top of coolant space 64 is 
delivered out of bleed line 62 back to the interior of tank 30. Since the 
total amount of liquid and total amount of air in the lines and the 
interior of tank 30 and the interior of coolant jacket 58 are constant, 
the air thus returned to tank 30 takes up the space of coolant which was 
transferred from tank 30 to fill jacket 58. Thus, upon actuation of valve 
44, coolant quickly fills coolant space 64 to quickly chill tube 54 which 
serves as the wall of freezing chamber 56. Tube 54 is maintained as thin 
as practical in order to minimize the thermal capacity of the system. 
Insulation 65 around the jacket and appropriate parts of the freezing 
chamber aids in limiting thermal loss. 
At the end of the freezing cycle, it is desirable that all coolant return 
to tank 30. In order to achieve this, vent line 66 is connected from the 
air space at the top of tank 30 to the highest point of the coolant system 
(in the present instance, where delivery line 46 enters the coolant 
jacket). Thus, with closing of valve 44, air vents via line 66 to the top 
of the system while the coolant liquid in coolant jacket 58 and return 
line 60 drains back into coolant tank 30. 
Bearing housing 68 is mounted on the top of tube 54. It contains bearings 
70 and 72 which rotatably support shaft 74 therein. Wall 76 closes the top 
of freezing chamber 56, and shaft 74 extends downwardly through wall 76 
into the freezing chamber to terminate adjacent the bottom thereof. The 
top of shaft 74 carries motor 78 which rotates the shaft when the motor is 
energized. The motor is controlled by master control unit 50 through timer 
80 which forms part of the control system. 
The lower end of freezing chamber 56 can be closed by hatch 82 (see FIG. 1) 
which is controlled by motor 84. Motor 84 is a solenoid or rotary motor 
which controls the opening and closing of the hatch. Motor 84 is 
controlled by timer 80. When hatch 82 is in its closed position shown in 
FIG. 1, the freezing chamber is totally closed, so that upon the 
introduction of food thereto, air must be discharged. Vent 86 is 
controlled by solenoid valve 88. The valve is also controlled from timer 
80 so that, when food is introduced into the freezing chamber 56, 
displaced air can be vented out of vent 86. 
Beater blades 90, 92 and 94 are equally spaced around shaft 74 and are 
secured to the lower portion thereof. They occupy nearly the entire space 
within freezing chamber 56 and nearly touch top wall 76, hatch 82, and the 
freezing wall of tube 54. A clearance of 0.002 to 0.003 inch in each of 
these places is satisfactory, although more clearance can be tolerated at 
the ends, and there is preferably less clearance between the beater blades 
and the tube wall. 
The scraping edge of the beater blades is provided with a screwthread. The 
screwthread has preferably two starts with a net pitch of 5 threads to the 
axial inch and is cut 0.062 inch deep along the edges of the blade. Thread 
start 96 has a standard 60 degree V. Thread start 98 has a curved bottom 
(again to 0.062 inch deep) but, instead of being V-shaped, it has a 0.120 
radius. The effect of these threads is that the angular action forces the 
product downward, while the radius thread 98 allows a greater portion of 
the product to come into contact with the wall of the freezing chamber to 
produce efficient freezing. Each beater blade has a series of holes 100 
therein. For a beater chamber of 2.50 inches diameter and 5.25 inches 
long, 8 holes 100 of 3/8 inch diameter along each of the beater blades set 
at 3/16 inch from the cutting edge of each blade is suitable. These holes 
are placed along the blade so that each hole overlaps with, but is not 
directly in the line with, the hole on the preceding blade. 
FIG. 1 illustrates the food-dispensing unit 102. Reservoirs 104, 106 and 
108 each contain liquid food material. The food material can be selected 
from fruits or vegetables and can be juice or a puree of pulp and juice. A 
wide variety of foods can be employed. Juices of tree fruits, berries, and 
other fruits, as well as vegetable juices, and purees of fruits and 
vegetables are suitable materials to serve as liquid starting material for 
the present food article. Selected food material liquids are placed in the 
reservoirs. Three reservoirs are employed so that selection of the 
character of the resultant frozen food article can be made. The three 
reservoirs are suitably closed and are pressurized by air pump 110'. The 
outlets of the three reservoirs are selectively controlled by solenoid 
valves 110, 112 and 114 which, in turn, are controlled from the master 
control unit 50. Each of these valves has its outlet discharge to liquid 
food material inlet 116 into freezing chamber 56. Agitation can be 
provided in the reservoirs, if such is necessary to maintain the juices or 
purees in appropriate suspension. 
In standby operation, compressor 12 cycles as necessary to maintain coolant 
32 at the desired temperature (preferably 10 degrees F. below Zero) as 
detected by sensor 36. Coolant pump 38 is cycled often enough to prevent 
stratification of the coolant in tank 30 and to maintain pump 38 and 
associated parts chilled. In this recirculating condition, valve 44 is 
positioned to direct the recirculating liquid back through recirculating 
line 48. In the standby condition, hatch 82 may be opened to maintain the 
freezing chamber 56 in the ventilated condition, but is preferably closed 
to maintain cleanliness. 
In order to start the cycle, first the flavor selector on master control 
unit 50 is actuated to the desired flavor. Next, switch 118 is operated to 
start the cycle. Switch 118 may be a manual switch, or it may be a part of 
a coin acceptor so that the system can be a coin-operated system. First, 
if hatch 82 is open, it is closed by its controller 84. Next, the selected 
solenoid valve 110, 112 or 114 is opened to allow a measured amount of 
liquid food material to be discharged into freezing chamber 56. The liquid 
food material is propelled by the air pressure in its reservoir. Valve 88 
opens vent line 86 during the filling operation. Simultaneously with the 
start of filling, valve 44 is actuated so that coolant is delivered to 
coolant space 64. At the same time, coolant pump 38 is actuated to remain 
on independent of the recirculating requirements. 
Next, about 2 to 3 seconds later, the master control unit starts motor 78 
to actuate the beaters causing the liquid food material to be mixed and 
whipped as it freezes on the chamber walls. The amount of liquid food 
material forced into the freezing chamber is a time function so that, when 
the proper time is elapsed, the liquid food material control valve is 
turned off and, at the same time, vent 86 is closed. About 4 ounces of 
liquid food material is discharged into the freezing chamber which has a 
capacity of about 13 fluid ounces. With the beater operating and the walls 
in the freezing chamber below the freezing point of the liquid food 
material, liquid is thrown against the walls to freeze. The effect of the 
staggered holes 100 in the beater blades is that the product being frozen 
is constantly being beaten, exchanged, and evenly distributed throughout 
each of the three compartments between the three beater blades. This even 
distribution of the product prevents vibration of the product being 
frozen. Furthermore, as the product is being frozen, it is forced through 
the holes 100 in a relatively tubular fashion as indicated at 122 and then 
forms a vertical cylinder of frozen food as indicated at 124, along the 
leading edge of blade. This cylinder 124 is constantly turning and picks 
up the frozen food product from the walls of the chamber which were left 
by the threads in the edges of the beater and the tubular-type trailings 
122 left by the holes 100 in the preceding blades. The result is a 
uniformly smooth frozen product with very fine crystallization. 
This configuration of the holes mixes air from the freezing chamber into 
the liquid and crystalline ingredients producing a light, fluffy frozen 
food article. This override aeration of the structure provides a lighter, 
smoother frozen food article. The override is the difference in volume 
(the output volume minus the input volume) so that a full measure is 
provided. 
After an appropriate length of time (depending on the amount of liquid food 
material and the cooling capacity, and in the preferred embodiment 
disclosed after about 55 seconds), controller 84 opens hatch 82 to 
dispense the frozen food article into cup 120. At the same time, valve 44 
is returned to its recirculation position, all coolant fluid 32 is 
returned to tank 30, leaving chamber 56 empty, ready for the next cycle, 
and coolant pump 38 is returned to demand control. After an appropriate 
length of time after the dispensing of the product, the beater motor is 
turned off and the hatch 82 is closed so that the system is ready for the 
next cycle. The system is in standby condition ready to quickly produce 
another frozen food article; however, in the standby condition, no rime 
ice is formed in the freezing chamber to dilute subsequent articles or to 
cause freeze-up of beater blades to cylinder wall. 
This invention having been described in its preferred embodiment, it is 
clear that is is susceptible to numerous modifications and embodiments 
within the ability of those skilled in the art and without the exercise of 
the inventive faculty. Accordingly, the scope of this invention is defined 
by the scope of the following claims.