Apparatus for cutting blocks of ice

An apparatus for cutting blocks of ice has a frame which defines a feed chute slightly larger than the uncut block of ice. Four saws are mounted to the frame in pairs. Each pair of saws includes two counter rotating, radial saw blades aligned opposite each other and extending toward one another into the feed chute of the frame. To facilitate the transfer of the uncut block of ice into the feed chute, a feed assembly is attached to the frame. A discharge assembly is secured to the frame to assist in removing the cut ice from the frame. The frame is mounted on a stand in an inclined position with the feed assembly higher than the discharge assembly to allow gravity feed of the ice. A gang of blades may be used with the saws in order to cut the block of ice into smaller sized blocks with one pass through the feed chute. The saw blades have carbide-tipped saw teeth to extend the amount of use between resharpening or replacement. Cutouts are formed in the saw blades to compensate for extreme temperature changes by allowing the saw blades to expand and contract without warping.

FIELD OF THE INVENTION 
The present invention relates to an apparatus for cutting blocks of ice and 
particularly to an apparatus for cutting blocks of dry ice. 
SUMMARY OF THE INVENTION 
Blocks of dry ice are normally produced in the United States in sizes of 
20".times.20".times.12" and weights of up to 240 pounds. Because this 
bulky size is difficult to handle, these blocks are often reduced to 
10".times.10".times.12" blocks weighing about 60 pounds. Large band saws 
are often used to cut these blocks. 
Smaller blocks of dry ice, however, are frequently more suitable to 
customers' needs. For example, 2".times.10".times.12", 
1".times.10".times.12" and 5".times.5".times.12" sizes are popular. The 
conventional way to produce these smaller sizes is by making individual 
cuts of the 60-pound blocks with manually-operated band saws. An apparatus 
constructed in accordance with the present invention, however, cuts a 
block of ice more efficiently and economically than conventional band 
saws. 
In the present invention, a frame defines a straight feed chute through 
which a block of dry ice is passed to cut the block of dry ice into a 
predetermined number and size of smaller blocks of dry ice. The frame 
supports two pairs of saws having at least one radial saw blade. The 
blades of each pair of saws extend into the frame toward one another from 
opposing sides of the frame. Each pair of saw blades are perpendicular to 
the other pair of saw blades to produce rectangular blocks of ice. 
One object of the present invention is to provide an apparatus which 
rapidly cuts dry ice and can be configured to cut the ice in a variety of 
sizes. 
A second object of the present invention is to cut blocks of ice with less 
labor and with smaller cutting losses than can accomplished with manually 
operated band saws. 
A third object of the present invention is to provide an apparatus with 
blades which can be maintained for extended periods without resharpening 
and which can be easily replaced when necessary. 
Other objects, features and advantages of the present invention will become 
apparent from the following detailed description when read in conjunction 
with the accompanying drawings and appended claims.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Referring to the drawings in detail and to FIG. in particular, reference 
character 10 generally designates an ice-cutting apparatus constructed in 
accordance with the present invention. Reference numeral 20 indicates an 
uncut block of dry ice with typical dimensions of 10".times.10".times.12". 
The block of ice 20 has lateral surfaces 22 which are 10".times.12" and 
end surfaces 24 which are 10".times.10". Reference character 20C 
designates a cut block of ice. As shown in FIG. 1, the block of ice 20 is 
cut into four 5".times.5".times.12" blocks of ice. 
As illustrated by FIG. 1, the ice-cutting apparatus 10 includes a frame 30 
with an open input end 32 communicating with an open output end 34. The 
frame 30 is sized and shaped to define a straight feed chute for feeding 
the block of ice 20 through the frame 30 from the input end 32 of the 
frame 30 to the output end 34 of the frame 30. Preferably the feed chute 
is slightly larger than the block of ice 20 to be cut. 
Four saws 36 are mounted to the frame 30. Two saws 36a and 36b are 
positioned toward the input end 32 of the frame 30 and two saws 36c and 
36d are positioned toward the output end 34 of the frame 30. Two mounting 
plates 38 secured by a pair of supports 42 are attached to the frame 30 to 
provide a mounting surface for each pair of saws 36a-36b and 36c-36d. 
A feed assembly 44 is attached to the input end 32 of the frame 30 to guide 
the block of ice 20 into the input end 32 of the frame 30. A discharge 
assembly 46 is connected to the output end 34 of the frame 30 to receive 
the cut block of ice 20C. 
The frame 30, feed assembly 44 and discharge assembly 46 are preferably 
attached to a stand 48. The stand 48 is mounted on a set of wheels 50 to 
facilitate movement of the apparatus 10 from one location to another. The 
stand 48 also includes a pair of stops 52 to prevent the apparatus 10 from 
moving while in operation. As shown in FIG. 1, the frame 30, feed assembly 
44 and discharge assembly 46 are mounted on the stand 48 in an inclined 
position with the input end 32 higher than the output end 34. The inclined 
position allows the block of ice to be fed into the frame 30 with the 
assistance of gravity. Also attached to the stand 48 is a control panel 54 
containing circuit devices for providing electrical power to the saws 36. 
FIGS. 2 and 3 illustrate one of the saws 36 in detail. As shown in FIG. 2, 
each saw 36 includes a motor 56, a shaft 58, a radial blade 60 affixed to 
the shaft 58, and a pair of bearing assemblies 62. The bearings 62 are 
fixed to the frame 30 and the shaft 58 is located between each pair of 
bearings 62 with the shaft end 74 extending through one of the bearings 62 
to connect to a coupling 64 between the motor 56 and the shaft 58. The 
coupling connection between the motor 56 and the shaft 58 is keyed and 
set-screwed. A lock nut 66, lock washer 68, two spacers 70 and a 
compression plate 72 position the blade 60 at the desired location on the 
shaft 58. Spacers 70 having various lengths may be used to change the 
position of the blade 60 on the shaft 58. The blade 60 is keyed to the 
shaft to prevent rotation of the blade about the shaft 58. Each bearing 
assembly 62 has a plurality of mounting holes 78 for attachment of the 
bearing assembly 62 to the frame 30. The motor 56 has a mounting plate 80 
with mounting holes 82 for attachment of the motor 56 to the frame 30. 
Each motor 56 is preferably an electric, five horsepower motor, although 
hydraulic or pneumatic power sources could be utilized if available. For 
simplicity of operation, it is preferred that the shafts 58 are directly 
driven by the motors 56, but the shafts 58 could be belt-driven to allow 
for speed adjustments. The blades 60 are driven at approximately 3600 
revolutions per minute. 
The blades 60 of the saws 36 are preferably high-tensile steel with 
carbon-tipped blades. The hardness and durability of certain grades of 
carbide allows such blades to be used at high surface cutting speeds 
without resharpening for extended periods of time. The surface cutting 
speed is calculated by multiplying the circumference of the blade in feet 
times the revolutions per minute of the blade. A 14-inch diameter blade at 
3600 revolutions per minute would have a surface cutting speed of 13,195 
surface feet per minute. High surface cutting speeds, such as speeds above 
10,000 surface feet per minute, enable the blades 60 to cut an ice block 
in rapid fashion. The 14-inch diameter carbon-tipped blade at 3600 
revolutions per minute would typically cut a 10".times.10".times.12" block 
of ice in just a few seconds. 
Referring now to FIG. 4, the frame 30, feed assembly 44, discharge assembly 
46 and stand 48 are described in detail. The open input end 32, the open 
output end 34 and the four sides of the frame 30 define a straight feed 
chute, indicated by the arrow 83, for the block of ice 20 through the 
frame 30. The shafts 58 of the saws 36 pass through slots 84 of the frame 
30 and the bearing assemblies 62 mount to the outside of the frame 30 over 
the slots 84. Mounting the bearing assemblies 62 on the outside of the 
frame 30 allows easy removal of the bearing assemblies 62 and shaft 58 for 
replacement of saw blades 60. The mounting surface 38 for each pair of 
saws 36 is attached to the frame 30 and braced by support members 42. With 
the motors 56 fastened to the mounting surfaces 38 and the bearing 
assemblies 62 attached to the frame 30, the saws are securely mounted to 
the frame 30. 
Each side of the frame 30 comprises a plurality of side members extending 
from the input end 32 of the frame 30 to the output end 34 of the frame 30 
and separated from each other by spaces. One of the side members, 
designated by reference numeral 86, is generally representative of the 
side members. The side members 86 keep the block of ice straight as the 
block of ice moves through the frame 30 and each space between the side 
members 86 is available to receive one of the saw blades 60. With the 
shaft 58 of each saw 36 positioned in one of the slotted areas 84 of the 
frame 30, a portion of the respective saw blade 60 extends through one of 
the spaces into the feed chute of the frame 30. Several spaces are defined 
by the side members 86 in each side of the frame 30 so that various 
numbers and arrangements of saw blades 60 may be used. A portion of each 
saw blade 60 also extends outside the frame 30. To protect the operator 
from the blades 60 and rotating parts outside the frame 30, a blade guard 
88 is attached to the frame 30 to enclose each saw blade 60. The blade 
guards 88 also provide a containment for the "ice-dust" produced by the 
blades 60 in cutting the block of ice 20. 
Continuing to refer to FIG. 4, the feed assembly 44 is attached to the 
input end 32 of the frame 30 and comprises a plurality of rollers mounted 
between two support members 90. One of the rollers is designated by 
reference number 92 and is generally representative of the feed assembly 
rollers. The rollers 92 are adapted to rotate as indicated by direction 
arrow 94 to facilitate the feeding of the block of ice 20 into the feed 
chute 83 of the frame 30. A feed guide member 96 is attached to each feed 
support member 90 to maintain the block of ice 20 in proper alignment as 
the block of ice 20 is fed into the feed chute 83 of the frame 30. 
The discharge assembly 46 is similar to the feed assembly 44 in 
construction. The discharge assembly 46 has a plurality of rollers 98 
between two discharge support members 100. The discharge rollers 98 rotate 
as indicated by direction arrow 102 to facilitate the removal of the cut 
block of ice 20C from the frame 30. A pair of discharge guide members 104 
maintain the block of ice 20C in proper alignment on the discharge 
assembly rollers 98. 
As pictured in FIG. 4, the frame 30, feed assembly 44 and discharge 
assembly 46 are mounted on the stand 48. Also mounted to the stand 48 is 
the control panel 54 which is connected to an electrical power source (not 
shown) via an electrical power cord 106. The control panel 54 provides 
electrical connections and control circuitry for the saws 36. 
FIG. 5 illustrates the use of pairs of saw blades 60 to cut the block of 
ice 20. An advantage of the present invention is the use of two smaller 
blades rather than one larger blade in order to obtain a narrower cut. As 
the diameter of a radial saw blade is increased, the thickness of the 
blade must also increase to provide the strength and rigidity required to 
withstand the additional circumferential and radial forces resulting from 
the increased size. To use a single blade to cut through a 10-inch depth 
requires a blade of at least 22 inches in diameter and more probably 24 
inches in diameter (allowing for the diameter of the supporting shaft). 
Assuming that the blades are made of the same material, a 22- or 24-inch 
diameter blade is more than twice as thick as two narrower opposing blades 
14 inches in diameter. The use of two narrower opposing blades, therefore, 
results in a narrower cut in the ice and less material loss. 
As FIG. 5 indicates, the two opposing blades 60a and 60b are adapted to 
rotate on shafts 58a and 58b respectively in directions counter to one 
another. The counter rotation of the two blades 60a and 60b is shown by 
the direction arrows 110 and 12. The direction of the movement of the 
block of ice 20 is indicated by reference numeral 114. This design 
prevents "climb cutting," which is the riding up of the blade on the 
material to be cut. By the use of counter-rotation, each blade 60a pushes 
the block of ice 20 toward the other blade 60b and vice versa, causing a 
more efficient cut of the block of ice 20. 
The opposing blades 60a and 60b are in near engagement with one another but 
do not contact one another. A space, indicated by reference number 115, is 
present between the blades 60a and 60b. Accordingly, a thin strip of uncut 
ice results from the space 115 between the blades 60a and 60b. The strip 
of uncut ice is easily broken by applying pressure to the cut block of 
ice. 
FIG. 6 illustrates that a gang of blades rather than a single blade may be 
attached to the shaft 58 of each saw 36. The saw 36A in FIG. 6 has two 
radial blades 60A equally spaced on the shaft 58 of the saw 36A. The use 
of the saw 36A to cut a 10-inch block of ice, therefore, would result in 
three 3.33-inch blocks of ice. 
Referring now to FIG. 7, the construction of the saw blade 60 is described 
in detail. Each saw blade 60 is generally circular with a plurality of 
circumferential saw teeth. One of the saw teeth is designated by reference 
numeral 116 and is generally representative of the saw teeth of each saw 
blade 60. Each saw tooth 116 is preferably carbide-tipped to extend the 
length of time between replacement or resharpening of the saw blades 60. 
One of the carbide tips is indicated by reference number 118. 
Between the saw teeth 116 are gullets. One of the gullets is designated by 
reference numeral 120 and is generally representive of the gullets. A 
temperature-compensating cutout 122 extends from the root of four of the 
gullets 118 to the interior of the saw blade 60. The four cutouts 122 are 
spaced at ninety-degree intervals around the saw blade 60 and are in the 
shape of an elongated slot 124 open at the root of the gullet 120 and 
enlarged into a round hole 126 at the interior of the saw blade 60. The 
cutouts 122 allow movement of the saw blade 60 along the slots 124 as the 
saw blade 60 expands and contracts with extreme changes in temperature. 
This temperature-compensating design reduces compressive forces on the saw 
blade 60 as the saw blade 60 is subjected the low temperatures of dry ice 
and helps prevent warping of the saw blades 60. 
Continuing to refer to FIG. 7, the direction of the saw blade 60 rotation 
is indicated by direction arrow 128. A mounting hole 130 in the center of 
the saw blade 60 is provided to attach the saw blade 60 to the shaft 58. 
The mounting hole 130 includes a keyway 132 to fit with a key (not shown) 
on the shaft 58 to ensure that the blade 60 rotates with the rotation of 
the shaft 58. 
Because dry ice is widely used in conjunction with food preparation and 
storage, all surfaces of the apparatus 10 which come into contact with the 
ice must be made of materials conforming to state and federal health 
standards. Accordingly, the inner surfaces of the frame 30, the feed 
assembly 44, the discharge assembly 46 and the saw blades 60 are be 
constructed with approved materials. 
Changes may be made in the combinations, operations and arrangements of the 
various parts and elements described herein without departing from the 
spirit and scope of the invention as defined in the following claims.