Potato cleaning table

A cleaning table for sorting newly harvested potatoes or other vegetables from vines, dirt, clods, rocks and other debris. The table includes a deck comprised of a plurality of spaced apart, parallel longitudinal rollers that operate in pairs of counterrotating rollers which rotate toward one another when viewed from the top. The rollers are formed of an elastically deformable material such as rubber, soft plastic or the like. One of each pair of rollers can have an elongate helical rib or flight extending from end to end. As potatoes and associated debris move longitudinally along the rollers, the dirt, vines, clods and other debris are separated from the potatoes and fall between the spaces between the rollers. Hard objects pass between the rollers without damage to the rollers.

SUMMARY OF THE INVENTION 
The invention pertains to a table for cleaning vegetables such as potatoes 
by separating the vegetables from dirt, vines, clods, rocks and like trash 
or debris that is lifted from the ground with the vegetable. Potatoes and 
like vegetables present a unique problem upon harvest because they are 
well rooted in the ground and are lifted from the ground with considerable 
quantity of stem, dirt, clods, rocks and other such debris. In addition, 
potatoes are fragile and must be handled carefully upon separation from 
the trash. 
The invention comprises a cleaning table for sorting newly lifted potatoes 
from vines, dirt, clods, rocks and other trash. The table includes a deck 
comprised of a plurality of spaced apart, parallel longitudinal rollers. 
The rollers operate in pairs of counter rotating rollers which rotate 
toward one another when viewed from the top. The rollers are formed of an 
elastically deformable material such as rubber, soft plastic or the like. 
One of each pair of rollers has an elongate helical rib or flight 
extending from end to end. The other roller can be smooth or can have a 
corresponding helical rib or can be formed with straight longitudinal 
ribs. The table is disposed with the rollers at a longitudinal 
inclination. Newly harvested potatoes, along with the corresponding trash, 
are deposited on the upper end of the table. The potatoes travel down the 
table toward the lower end. Under the influence of the rotating rollers, 
the vines, trash, clods, rocks and the like are separated from the 
potatoes and fall through the spaces between the rollers. The helical ribs 
advance the potatoes and break up dirt clumps and other debris to force it 
between the rollers while moving the potatoes off the end of the table. 
The soft covering of the rollers prevents damage to the potatoes. Rocks 
which pass through the spaces between the rollers do not damage the 
rollers.

DESCRIPTION OF PREFERRED EMBODIMENTS 
Referring to the drawings, there shown in FIG. 1 a cleaning table 20 
according to the invention installed for receipt of potatoes from an input 
elevator or conveyor 21 and poised for discharge of potatoes to an output 
conveyor or spud chain conveyor 22. Potatoes 24 along with associated 
debris 25 such as vines, dirt, rocks, clods and the like travel along 
input conveyor 21 and are deposited on cleaning table 20. The potatoes 
travel along the cleaning table 20 and are discharged at the opposite end 
thereof onto output conveyor 22. Associated debris and trash 25 are 
eliminated along the length of table 20. 
Table 20 includes a frame having a lateral forward frame member 26 and a 
lateral rear frame member 27 (see FIGS. 2 and 4), and longitudinal 
sidewalls 28, 29. The lower edges 31 of the sidewalls 28, 29 are comprised 
as outwardly extended upwardly open channels and are connected at their 
respective forward and rearward edges to the outer ends of the forward and 
rearward members 26, 27 by suitable means such as welding. Sidewalls 28, 
29 present upstanding side surfaces for cleaning table 20 to prevent 
spillage of potatoes as they travel longitudinally along the table. 
A plurality of cleaning rollers extend longitudinally between forward and 
rear frame members 26, 27 and laterally between the sidewalls 28, 29. The 
rollers are assembled in coplanar relationship and are disposed in pairs 
of first and second rollers 32, 33. As shown in FIG. 2, there are five 
such pairs of rollers 32A, 33A through 32E, 33E. The rollers of each pair 
are counterrotating or rotate toward one another as viewed from the top. 
Roller support means for each roller is comprised as a central, axial 
roller shaft 34. The forward and rearward ends of each roller shaft 34 are 
rotatably mounted in bearing blocks 36 mounted respectively on the forward 
frame member 26 and the rearward frame member 27. The bearing blocks 36 
are adjustably mounted on the forward and rearward frame members 26, 27 
for limited lateral adjustment to vary the space between the rollers of 
each pair. As shown in FIG. 3, forward frame member 26 has a plurality of 
elongate mounting slots 37. Mounting bolts 38 extend downward from bearing 
blocks 36 through the mounting slots 27 and are secured by nuts 39. 
Loosening of the nuts 39 permits some measure of lateral adjustment of the 
location of the mounting block 36 and the corresponding roller held by the 
bearing block 36. Spacing between corresponding rollers of each pair can 
be varied as desired and according to conditions of potatoes or other 
vegetables being cleaned on the table. 
Power means are provided to counterrotate the pairs of rollers 32, 33. 
Roller shafts 34 extend rearwardly beyond the rear frame member 27. The 
rearward end of each roller shaft 34 is equipped with a circumferencially 
grooved roller pulley 41. As shown in FIG. 4, an endless loop roller drive 
belt 42 is comprised as a double V belt trained along the grooves of the 
roller pulleys 41. Endless loop belt 42 is trained about a roller belt 
drive pulley 43 mounted on a shaft 45 rotatably fixed to sidewall 28 by 
clamps 46 (See FIGS. 1 and 2). Belt 42 is also trained about an idler 
pulley 47 mounted on a shaft 48 located beneath the drive pulley 43 and 
rotatably mounted to a plate 49 by clamps 51. Plate 49 is affixed to the 
lower edge of sidewall 28 extending beneath the drive pulley 43. Plate 49 
can be adjustably mounted with respect to the lower edge 31 of sidewall 28 
in order to adjust tension in endless loop belt 42. Belt 42 extends from 
idler pulley 47 to the roller pulley of the extreme end roller 32A and 
passes around and over the top of the roller pulley of end roller 32A. 
Belt 42 extends under and engages the next adjacent roller pulley, then 
alternately over and under adjacent roller pullies of the rollers until 
the opposite end pulley is reached. When belt 42 is driven, adjacent 
rollers are rotated in opposite directions giving rise to the pairs of 
counterrotating rollers. 
Belt 42 is driven by a chain and sprocket power transmission. A first 
sprocket 50 is secured to the shaft 45 of roller belt drive pulley 43. A 
second sprocket 51 is secured to a shaft 52 rotatably mounted on a plate 
53 depending from opposite sidewall 29 of table 20. A chain 55 is trained 
between the first and second sprockets 50, 51. A tension adjusting 
sprocket 56 is rotatably mounted on an arm 57 which extends from the frame 
of table 20. Tension adjusting sprocket 56 is in engagement with the drive 
chain 55 and is moveably mounted on the arm 57 so as to take up or relieve 
tension on the chain 55. 
Second sprocket 51 is driven by hydraulic motor 59 through a universal 
linkage assembly 60. One end 61A of an adjustable link is equipped with a 
first universal coupling 63 which is connected to the second sprocket 51. 
The outer end 61B of the adjustable link is telescopically engaged in the 
first end 61A and has an end equipped with a second universal coupling 64. 
Motor 59 is located on a stand 65 and has an output shaft 66. A chain and 
sprocket assembly 68 connects the output shaft 66 to an intermediate shaft 
69 carried by bearings 70 mounted on a plate 71 and held on a column 73 
fixed to the stand 65. Intermediate shaft 69 is connected at its opposite 
end to the second universal coupling 64 whereby the operation of the motor 
59 results in rotation of the second sprocket 51 with the result of 
counterrotation of the rollers 32, 33 of cleaning table 20. Universal 
linkage assembly 60 is extendable and retractable and, by virtue of the 
universal coupling 63, 64 it is operable at selected angular orientations. 
The cleaning table rollers 32, 33 are comprised of a soft, resilient 
elastically deformable material such as rubber or plastic or the like 
having a durometer value between forty and fifty-five. The first roller 32 
of each pair includes an elongate helical or spiral rib 74 extended from 
end to end wound about the cylindrical roller surface or body portion 72. 
The helical rib is comprised of the same resilient material as the body 
and can be integrally formed with the body of the roller. As shown, the 
cylindrical roller surface or body of the second roller 33 is smooth. A 
particular construction of the spiral roller 32 is shown in FIGS. 6 
through 9 where a portion of a first roller 32 is shown in FIG. 6. Roller 
32 is comprised of a plurality of roller segments shown to include the 
segments 75, 76 and 77 assembled on the roller shaft 34. Each of the 
segments has a central opening to be slip-fitted on the roller shaft 34. 
Each segment is cylindrical and carries a fragmented helical rib portion 
74A, 74B, 74C along its surface. In assembled relationship, the helical 
rib segment portions 74A, 74B, 74C are aligned to form a continuous 
helical rib 74. Each roller segment has a circular opening 79 on one end 
surface thereof, and an outwardly extended projection or finger 80 on the 
opposite surface. The openings 79 and fingers 80 are so positioned such 
that the finger 80 of one segment 75 is insertable in the opening 79 of 
the next segment 76 with the helical segment portions 74A in proper 
alignment. 
As shown in FIGS. 3 and 10 the second roller 33 of each roller pair has a 
cylindrical body portion 80 with a central opening for accommodation of 
the roller shaft 34. Body portion 82 is formed of a soft, resilient 
elastically deformable material such as rubber or plastic. The body 
portion 82 can also be formed of a plurality of cylindrical segments 
assembled together on the roller shaft 34. End caps 83 are provided on the 
roller shaft 34 at the ends of the body portion 82 to hold the roller body 
portion in place. 
As shown in FIGS. 1, 2, 4 and 5, cleaning table 20 is adjustably assembled 
to the discharge end of input conveyor or elevator 21. Input conveyor 21 
includes a housing having sidewalls 84 connected between a top wall 85 and 
bottom wall 86. The housing is supported at an inclination on a leg 87 
attached to a boss 89 fixed to the bottom wall 86. A conveyor belt 90 is 
disposed within the housing of the input conveyor 21 and driven in 
conventional fashion by a motor 91 to carry potatoes 24 to and through the 
output end of the conveyor. 
A pair of brackets 93A, B pivotally connect cleaning table 20 to the 
discharge end of input conveyor 21. As shown in FIG. 4, the upper end of 
an elongate bracket 93A is fastened to sidewall 84 of input conveyor 21 by 
a pair of fasteners such as bolts 94A. The lower end of bracket 93A 
extends rearwardly and downwardly, and is connected to the sidewall 28 of 
cleaning table 10 by a pivotal connection such as a bolt 95A. The upper 
end of the opposite bracket 93B is connected by a pair of fasteners such 
as bolts 94B to the opposite sidewall 84 of cleaning table 10. The lower 
end of bracket 93B is pivotally connected to the opposite sidewall 29 of 
cleaning table 10 by a pivotal connection such as a bolt 95B in axial 
alignment with the first bolt 95A to pivotally connect the cleaning table 
20 to the end of input conveyor 21. 
Cleaning table 20 is further connected to input conveyor 21 by adjustable 
linkage means shown to include a first turn-buckle assembly 97 (FIGS. 1 
and 4). A first side plate 98 extends upwardly along the first sidewall 28 
of table 20. The base of side plate 98 is located in and rests in the open 
channel of the lower edge 31 of sidewall 28. Side plate 98 extends beyond 
the upper edge of sidewall 28. A second side plate 99 is similarily 
positioned with respect to the second sidewall 20 of cleaning table 20. A 
transverse bar or brace 101 extends laterally across the top of cleaning 
table 20 and is connected at either end to the upper ends of the side 
plates 98, 99 (See FIG. 4). 
Turnbuckle assembly 97 includes a first bar 102 having a clevis end 103 
pivotally connected to an ear 104 fixed to brace 101. The opposite end 106 
of first bar 102 is reduced in diameter and is threaded. A second arm 107 
has a clevis end 108 pivotally connected to a lug 109 fixed at the end of 
input conveyor 21 on top wall 85. The opposite end 111 of second bar 107 
is reduced in diameter and is threaded oppositely to the end 106 of first 
bar 102. A turnbuckle yoke 112 engages the threaded ends 106, 111 of the 
first and second bars 102, 107. Rotation of the turnbuckle yoke 112 is 
effective either to move the bars 102, 107 toward one another or away from 
one another. 
A second turnbuckle assembly 113 is provided to assist in holding cleaning 
table 20 with respect to output conveyor 21 and is identical in 
construction to the first turnbuckle assembly 97 (See FIG. 5). Second 
turnbuckle assembly 113 is located laterally opposite the first turnbuckle 
assembly 97 with respect to the deck of cleaning table 20 and includes a 
first bar or rod 114 having a clevis end 116 in pivotal engagement with an 
ear 117 which is securely fixed to the transverse brace 101. The opposite 
end 118 of first bar 114 is reduced in diameter and is threaded. A second 
bar 119 has a clevis end 121 in pivotal engagement with a lug 122 fixed to 
the top wall 85 of the housing of input conveyor 21. The opposite end 123 
of second bar 119 is reduced in diameter and is threaded oppositely to 
that of the end 118 of first bar 104. A turnbuckle yoke 124 threadably 
engages both threaded 118, 123 of first and second bars 114, 119. Rotation 
of the turnbuckle yoke 124 is effective to draw together or move apart the 
first and second bar 114, 119. The turnbuckle yoke 124 of second 
turnbuckle assembly 113 and turnbuckle yoke 112 of first turnbuckle 
assembly 97 are rotated simultaneously to move the respective bars 
together or apart and pivotally move the cleaning table 20 with respect to 
the end of input conveyor 21. Such adjustment of the turnbuckle assemblies 
permits angular adjustment of the forward inclination of the rollers of 
cleaning table 20 as between positions shown in FIG. 1 and FIG. 5. 
The deck of cleaning table 20 formed by the pairs of rollers 32, 33 
discharges potatoes onto the output conveyor or spud chain conveyor 22 for 
movement of potatoes to a place of packing or storage. Output conveyor 22 
is of conventional construction having a conveyor comprised of a plurality 
of transverse rods 126 interconnected and driven by an electric motor 127 
and supported by legs 128. 
As shown in FIG. 5, in use of the cleaning table of the invention, freshly 
dug potatoes 24 together with associated debris 25 are delivered to the 
belt 90 on input conveyor 21. Turnbuckle assemblies 97, 113 are used to 
adjust the inclination of the rollers of table 20 according to the type 
and nature of debris associated with the potatoes 24. The spacing between 
the rollers of each pair or set is adjusted according to the size of small 
potatoes to be eliminated. If the rollers are set close enough so that the 
pitch angle of the roller pair, or that space between the rollers which 
will result in an object wedging between then upon counterrotation, is 
less than the diameter of the smallest potato, then no potatoes will be 
eliminated. If small potatoes are to be eliminated, then the pitch angle, 
or spacing between the rollers, is increased and the small potatoes pass 
between the rollers with the trash. 
Motor 57 is operated to drive the rollers with a surface velocity 
preferable between 200 ft. (61 m.) per minute and 450 ft. (137 m.) per 
minute. Potatoes and associated debris are discharged upon the rearward 
ends of the rollers 32, 33. The inclination of the table and helical 
spiral of the first rollers 32 cause movement of potatoes along the table. 
Dirt, clods of dirt, weeds, vines, and trash are removed from the potatoes 
and fall between the rollers. The rollers gently pass the potatoes without 
damage and discharge them off the end. Due to the resiliency of the 
rollers, the potatoes are moved to an elevation above the debris and 
quickly move over the rollers at a level higher than the dirt and trash 
and permit the dirt and trash to be captured by the rollers. The resilient 
material of the rollers also aids through its high friction coefficient in 
breaking up and pulling through the weeds, vines, trash, dirt and clods. 
As shown in FIG. 10, when a stone 135, or other hard material is 
introduced to the cleaning roller set and, if its size falls within the 
pitch angle of the rollers, rather than jamming the mechanism and causing 
stalling and possible damage, the resilient material compresses and 
permits the hardened material to be sorted with the trash, vines, dirt and 
the like. The resilient rollers are soft and prevent damage to the 
potatoes. The durometer value of the roller body can be between 40 and 55. 
Since the surface velocity of the rollers generates high inertia, the 
power requirement is less when a hard object is compressed between the 
rollers as it passes through. The centrifugal force of the rollers at the 
given velocity prevents wet dirt from clinging to the rollers and causing 
operational problems. 
The pitch of the helical rib of the first roller is related to the volume 
of dirt and trash to be removed from volume of potatoes to be cleaned. For 
example, if the volume of dirt, clods, trash and the like is high as 
compared to the volume of potatoes, the pitch will be smaller than when 
the volume of dirt, clods, trash and the like is low compared to the 
volume of potatoes. The helical rib, as it passes a dirt clod, breaks a 
piece from the clod with the broken piece passing between the rollers. The 
clod is broken again as the helical rib passes and so on until the clod is 
smaller than the pitch angle of the rollers and passes between the 
rollers. The helical rib serves to move the potatoes longitudinally across 
the table. While the trash, dirt, rocks, clods and the like are also moved 
by the helical rib, these different materials are moved slower than the 
potatoes and tend to remain close to the rollers, which greatly increases 
the opportunity for them to be captured by the rollers and discharged from 
the table. The pitch of the helical rib can, for example, be between one 
revolution in 20 inches of axial length to one revolution in 3 inches of 
axial length of the roller. 
As shown in FIG. 3, the second roller of each pair of rollers has a smooth 
outer surface. The second roller of each set of rollers could be comprised 
of another roller with a helical rib to remove exceedingly high volumes of 
dirt, vines and the like as compared to the volume of potatoes with a 
corresponding loss of some small potatoes. The second roller could also be 
comprised as a roller like the roller segment as shown in FIG. 11. A 
roller segment 130 has a central axial roller shaft 131 and a generally 
cylindrical body portion 132. Body portion 132 is formed of a soft, 
resilient material such as rubber. A plurality of longitudinal, parallel 
spaced apart straight ribs 134 are formed along the circumference of the 
body portion 132 and extend from end to end along the length of the 
roller. The ribbed roller 130 is effective in the removal of heavy volumes 
of dirt when required with only the loss of a few small potatoes. 
An alternative means of driving the pairs of rollers in counterrotating 
relationship is illustrated in FIG. 12. The ends of roller shafts 34 
extended rearwardly beyond rearward frame member 27 are equipped with 
circular spur gears 136 with each gear in meshing engagement with gears on 
either side. A power gear 137 is in engagement with an end gear 136. Power 
gear 137 is driven by a suitable source (not shown) as a hydraulic motor 
or the like. Power gear 137 drives the end gear 136 with resultant 
counterrotation of adjacent gears and resultant opposite rotation of 
rollers of each pair. 
While there has been shown and described certain preferred embodiments of 
the invention, it will be apparent to those skilled in the art that 
deviations and changes may be had from the embodiment shown in and 
described without departing from the scope and spirit of the invention.