Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
P~ETHOD ~D AP~ARAT~S FOR HELICAL CUl~IN~ OF POTATOES
.
Field of the Invention
The present invention relates to the cutting of vege-
tables preparatory to processing and in particular to the cut-
ting of potatoes into a plurality of helical strips.
Backgroun__Q~tbe Invent on
Raw potatoes and other vegetables have in the past been
cut into pieces for cooking or freezing in a variety of ways
using various apparatus. One method of cutting potatoes for
making a french fried potato product strip involves a fixed
i blade cutter against which a potato is rotated to cut it into a
plurality of helical strips. This mechanism incluaes a cutting
plate on which is mounted a pivot pin for engaging one end of a
~15 potato. The other end of the potato is engaged by a toothed
drive disk which is mounted opposite the plate on a crank driven
shaft. A set of slitting knives protrude from the surface of
the cutting plate and a cutting knife is mounted to the cutting
plate adjacent the pivot pin. The blade of this knife extends
radially from the pivot pin in a plane parallel to the surface
of the cutting plate. These knives cut the potato into a plu-
rality of helical strips as it is rotated against the cutting
plate.
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Although this device produces helically-cut potato
strips, it suffers from several problems. First, since the
potato is rotated against the cutting plate, a center core of
the potato is produced and progressively crushed against the
plate resulting in wastage and degradation of the product. The
toothed drive disk further results in waste since the potato
cannot be cut into helical strips Erom end to end without inter-
ference between the teeth of the drive disk and the cutting
knives. The speed of operation of this device is further limit-
ed by the time required to load a potato into axial alignment
with the pivot pin and drive disk and by the limitations on
rotational speed of the potato.
Brief Description of th-el nvention
The present invention overcomes the difficulties of the
prior art cutting device and provides a method for rapidly
cutting a potato into a plurality of helical strips without
~wastage of significant portions thereof. It has been found that
superior and rapid cutting of the potato can be achieved by
holding the potato against rotation and moving it into engage-
ment with a rotating cutter head. A high rotational speed of
the cutter head relative to the potato can thus be achieved,
resulting in the rapid reduction of the potato into a plurality
of helical strips. In order to achieve this result, a cutter
head is used which includes a plurality of slitting knives which
I extend outward in generally parallel alignment with the axis of
j rotation of the cutter head. These knives are positioned to
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form concentric longitudinal cuts in the potato. Helical strips
are then produced by a transverse blade, the cutting edge of
which protrudes from the face of the cutter head, as the cutter
head is rotated against the potato. The cutting head may in-
clude a center pin for engaging the potato or, alternately, may
include an upstanding cutting tube mounted at the center of
rotation of the cutting head. The end of this tube is sharpened
and cuts a cylinder of material from the center of the potato.
The remainder of the potato is reduced to helical strips which
have an internal radius at least as great as the radius of the
cutting tube. All of the helical strips are thus able to expand
lengthwise more freely and breakage thereof is less likely to
occur during the cutting process.
It has also been discovered that the potato can be held
against rotation during the cutting process without the use of
devices which penetrate and cut the potato and which may inter-
fere with the cutting of the entire potato into helical strips.
This is accomplished by use of a tubular potato holder which
includes a plurality fingers mounted to bear inwardly against
the potato. The inner sùrfaces of these fingers are blunt to
prevent cutting of the potato. In addition to their function in
holding the potato, these fingers also center the potato as it
is inserted into the holder.
The potato is forced into engagement with the cutting
head by means of a plunger. The sides of the plunger are deeply
d;~
grooved at locations corresponding to each of the Eingers so
that the plunger may be extended through the cup without inter-
fering with the holding and centering action of the fingers. In
order to maximize utilization of the potato, the plunger is
designed to be extended into the cup down to the rotating cut-
ting head. Concentric grooves are provided in the end of the
plunger to accommodate the upstanding slitting knives which
extend upward above the level of the transverse blade.
During operation of the cutting mechanism, the cutter
head is kept free from excessive debris by flowing water up-
wardly along its sides and over its surface. This water washes
through the aperture in the cutting head beneath the transverse
blade.
The cutting head is mounted on a rotatably driven tube.
This tube serves not only to conduct the rinsing water away from
the cutting head but also to conduct the helically cut potato
strips to a conveyor or bin. At high rotational speeds of the
cutting head, however, the helically-cut strips oE potato may be
held against the walls of the drive cylinder by centrifugal
force. In order to avoid this problem, a sleeve is mounted in
the tube to provide a non-rotating chute through which the water
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and potato strips are conducted away from the cutting head. In
addition, the base of the drive tube is surrounded by a splash
~5
shield which contains any water that may leak outward past the
top of the sleeve.
The feeding and cutting of the potatoes may be auto-
mated as a result of the aforementioned configuration of the
cutting mechanism. Preferably, one or more cutting mechanisms
are mounted on a table. An indexed table is provided with a
plurality of cups for receiving potatoes. The bottom of these
cups are open and positioned above a support plate. An indexing
mechanism is provided to rotate the indexed table in predetermi-
nal increments. When one of the cups is indexed into position
above the potato holder and cutter head, it drops through a hole
in the support plate and into the holder. A plunger mechanism
is then energized to force the potato downward against the
cutting head. When the cutting cycle is completed, the plunger
withdraws to a position above the cup, the indexing mechanism is
actuated, and the next cup is moved into position to deliver a
potato for cutting. Workers may be positioned about the periph-
ery of the machine to manually insert potatoes into the cups in
the indexed table. Potatoes may be supplied to these workers by
means of a conveyor ring around the machine which continuously
circulates the potatoes until they- are picked up for loading.
This conveyor may be supplied with potatoes by a vibrating
conveyor or other known conveyor mechanism.
Alternately, potatoes may be supplied to the cups by
means of an automatic feed mechanism. This feed mechanism may
comprise an annular conveyor which circulates about the machine
0
at a level above the cups. An ,infeed conveyor feeds potatoes to
the annular conveyor and is controlled in response to a sensor
to maintain an adequate supply of potatoes on the annular
conveyor. Diverter gates are positioned at various locations
about the annular conveyor to divert potatoes from the annular
conveyor to feed hoppers. Potatoes are fed from the hopper to a
vibrating chute which aligns the potatoes for cutting and trans-
ports them past an indexing mechanism which insures that no more
than a single potato is loaded into any cup. A curved gravity
biased plate engages potatoes released by the indexing mechanism
to guide them to the cup and prevent them from tumbling as they
are guid,ed into the cup. Potatoes may be swept onto the annular
convyeor from a belt conveyor and through a door by a diverter
gate which is movable between a retracted position, an extended
position and an intermediate position in response to signals
from two sensor pairs which monitor the presence of potatoes on
the annular conveyor.
The apparatus is preferably controlled by an automatic
sensing and control mechanism which automatically senses the
position of various of the elements of the apparatus and of the
sequences the operation thereof in response to this sensing.
Brief Descripti_n of the Drawings
Fig. 1 is a perspective view of an apparatus according
to the present invention.
Fig. 2 is an explo(3ed perspective view of the feeding,
holding and eutting meehanism of Fig. 1 with parts broken away.
Fig. 3 is a eross-seetional view of the feeding, hold-
ing and cutting meehanisms of Fig. 1 taken along the line 3-3 of
Fig. 1 with parts broken away.
Fig. 4 is a cross-sectional view of the plunger and
holding meehanisms of Fig. 3 taken along the line 4-4 of Fig. 3
with parts broken away.
Fig. 5 is a top plan view of the apparatus of Fig. 1
i with parts broken away.
Fig. 6 is a eross-seetional view of the eonveyor of
1 10
¦ Fig. 1 with parts broken away.
Fig. 7 is a top plan view of a cutter aecording to the
present invention.
¦ Fig. 8 is a eross-seetional view of a cutter assembly
15according to the present invention taken along line 8-8 of Fig.
Fig. 9 is an eleetrical schematie of the automatie
sensing and eontrol mechanism.
Fig. 10 is a schematie representation depicting the
loading of a potato into the holding means.
20Fig. 11 is a schematic representation of a potato in
position for eutting.
Fig. 12 is a schematic representation of a potato in
position for eutting.
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Fig. 13 is a perspective view of a helical strip of
potato,
Fig. 14 is a perspective view of an alternate potato
holding means.
I Fig. 15 is a view of a cutting blade assembly including
! 5 a center cutting tube.
Fig. 16 is a schematic representation of a potato being
cut by the cutting blade assembly of Fig. 15.
, Fig. 17 is a perspective view of an automatic feed
j system with parts broken away.
Fig. 18 is a perspective view of the indexing mechanism
of the feed system with parts broken away.
Fig. 19 is a perspective view of the feed chute and
indexing assembly with parts broken away.
Fig. 20 is a cross-sectional schematic of the feed
system with parts broken away.
Fig. 21 is a top schematic view of the feed system with
parts broken away.-
Fig. 22 is a cross-sectional schematic of the feed
system with parts broken away and showing the indexing mechanism
activated to stop the flow of potatoes along the chute.
Fig. 23 is a top schematic view of the feed mechanism
system with parts broken away and showing the hopper doors open
and the diverter gate extended.
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Fig. 24 is a flowchart of a programmable controller
used to control the sequence of operation of the present
~ apparatus.
j Detailed Descripti_n of ~he Preferred Em odiment
The present invention provides a new method and appara-
tus for rapidly and automatically cutting vegetables such as
potatoes into elongated helical strips. As best shown in Figs.
1, 2 and 3 this mechanism includes a frame 11 to which is mount-
ed a rotatable feed mechanism 12, which is driven by an indexing
~ system 13. A plunger system 14 and cutting system 16 are posi-
! lo tioned about the periphery of the device. A vibrating conveyor
3 mechanism 17 transports potatoes to an annular supply tray 18
which is rotatably mounted to the frame 11.
~ As best illustrated in Figs. 1-3 and 5 the feed mecha-
¦ nism 12 includes a feed table 19 mounted on a rotatable vertical
¦15 shaft 21. The table 19 is of generally circular configuration
and includes a plurality of open-bottomed feed cups 22 mounted
in apertures about its periphery. The open lower ends of the
i cups 22 are positioned immediately above an annular supporti plate 23 which is mounted to the frame 11 and supported above
the surface of the table 24 by a plurality of support legs 26.
As best illustrated in Figs. 2 and 3, a strip of low
friction plastic material 27 is positioned beneath the cups 22
and mounted to the support plate 23 by means of a plurality of
_ g _
countersunk screws 28. Apertures are provided in the support
plate 23 and plastic material 27 at positions such that potatoes
can be loaded into the eutting system 16.
Referring next to Figs. 1 and 5, the indexing mechanism
13 is operated by means of a pneumatie drive cylinder 29 and
pneumatie loeking eylinder 31. One end of the drive eyllnder 29
is mounted to the frame 11 and the other is attached to the free
end of a ratchet arm 32. The other end of the ratchet arm 32 is
pivotably mounted to the shaft 21. A pawl 33 is pivotably
mounted to the arm 32 ad]acent the attachment point of the drive
eylinder 29 and is spring biased into engagement with a ratchet
wheel 36 which is, in turn, mounted on the shaft 21. A pair of
limit switches 34, 35 are positioned, respeetively, to elose
when the eylinder 29 is in its fully retraeted and extended
positions. Extension of the drive eylinder 29 thus results in
rotation of the arm 32, pawl 33, ratchet wheel 36 and shaft 21.
Since the feed table 24 is also attached to the shaft 21, opera-
tion of the drive cylinder results in rotation of the table 24.
The length of the arm 32 and stroke of the cylinder 29 are
chosen such that operation of the eylinder further results in
sufficient movement of the table to position the next set of
cups 22 above the apertures 30 in the support plate 23.
The lock eylinder 31 actuates a locking mechanism 37
which prevents rotation of the cups 22 past the desired
location. As best shown in Figs. 1 and 5, this lock mechanism
37 comprises a lateh 38 which is mounted to the frame 11 and
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biased into en~agement with the teeth 39 formed in the edye of
the feed table 19 by a spring 41. The teeth 39 and latch 38 are
configured to restrict rotation of the table 19 such that each
feed cup 22 may be locked into position above the cutting system
16 in turn. Actuation of the lock cylinder 31 retracts the
latch 38 and frees the feed table 19 to rotate. The index table
I
may also, of course, be driven by an electric motor and the
position of the table sensed by cam actuated switches as is
known in the art.
Referring next to Figs. 1-3, the plunger mechanism 14
comprises four identical plunger units 42. Each plunger unit 42
1 10
¦ includes a double acting pneumatic cylinder 43 mounted to the
¦ frame 11 by upper and lower brackets 44, 46. The plunger head
47 is mounted on the shaft of the pneumatic cylinder 43. A rod
48 is mounted to the plunger head 47 and is slideably supported
¦ by the lower bracket 46 for vertical movement with the plunger
¦ 15 head 47. Upper and lower limit switches 49, 51 are mounted on
the upper and lower brackets 44, 46 in position for actuation by
i a tab 52 mounted on the free end of the rod 48, respectively,
when the pneumatic cylinder is fully retracted or extended.
Referring more particularly to Figs. 2-4, the plunger
~ ~ head 47 is formed with deep grooves 53 extending longitudinally
i along it sides. In addition, concentric circular grooves 54 are
formed into the lower surface of the plunger head 47. These
grooves 53, 54 cooperate with elements of the cutting mechanism
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16 as described below to provide complete and accurate cutting
of potatoes or other vegetable.
The cutting mechanism 16 comprises four identical
cutting units 56. As best shown in Figs. 1-3, these cutting
units 56 include a holder 57 for receiving and aligning potatoes
for cutting. The holder 57 also secures the potatoes against
rotation during the cutting process. The cutting units 56
include a rotatable cutter mechanism 58, a support 59 for rotat-
ably mounting the cutter mechanism to the table 24, and a drive
unit 61 for rotatably driving the cutter mechanism 58.
` 10 Referring more particularly to Figs. 2 and 3, the
holder ~7 includes a tubular body 62 mounted on a base plate 71
for receiving potatoes. A plurality of fingers 63 are hinged to
the body 62 adjacent its upper lip and extend into the body 62
through corresponding slots 64. The inner surface 66 of each
finger 63 is blunt-to prevent cutting of the potatoes held in
the body 62.
A pin 68 is pivotably connected to each of the fingers
63 and mounts a spring for independently biasing the correspond-
ing finger 63 into the interior of the tubular body 62. The
outer end of the springs 67 bear against a ring 69 which is not
mounted on the base plate 71 but rather is free to float as the
fingers 63 move upon positioning of a potato in the holder 57.
This allows the holder 57 to accommodate and align even highly
irregular potatoes concentrically with the tubular body 62. The
pins 67 extend through slots 72 in the ring 69 and include heads
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which bear against the outer surface of the ring 69 to limit
inward travel of the fingers 63.
As shown in Figs. 2 and 3, a pair of nozzles 65 are
mounted on the base plate 71 for supplying rinse water to the
cutting head 58. Some of the rinse water supplied to the cut-
ting head 58 may be impelled upward into the tubular body 62 of
the holder 57 and exit through the slots 64. The holder may
alternatively be constructed to remedy this problem. As shown
in Fig. 14, the water can be contained and prevented from flow-
I ing out onto the table 24 by mounting the ring 69 in a groove 70
! lo in the base plate 71. Any water which accumulates within the
confines of the ring 69 is drained away through one of the drain
¦ holes 75 in the base plate 71.
¦ As shown in Figs. 2, 3, 7 and 8, the cutter mechanism
¦ 58 includes a blade assembly 74 and a flanged blade mount 76.
I The blade assembly 74 is generally disk shaped and includes a
1 15
I raised transverse blade 77 the edge of which extends radially
! from the center of the assembly 74. The transverse blade 77 is
supported above the surface of the assembly 74 by a shoulder 75
on the opposite side of the center of the assembly 74. A plu-
¦ rality of upstanding slitting knives 78 extend upwardly from the
surface of the blade assembly 74 and are removably attached
thereto for example by soldering. The slitting knives extend
, upward from the surface oi the assembly 74 to a position ap-
', proximately 1/16 of an inch above the upper surface of the
transverse blade 77. A center pin 79 is attached to the trans-
verse blade 77 at the center of the blade assembly 74. The pin
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79 does not extend below the lower surface of the transverse
blade 77 nor do any obstructions depend from the lower surface
of the blade assembly. This minimizes damage and breakage of
the spiral strips of potatoes as they are cut and eliminates
crushing of any portion of the potato against the surface of the
blade assembly 74. The piercing action of pin 79 adjacent the
edge of blade 77 produces an inner helical strip in lieu of a
core.
The blade assembly 74 includes a plurality of mounting
holes 81 about its periphery which correspond to holes 82 in the
recessed interior flange 83 of the blade mount 76. Flush mount-
ing screws (not shown) are used to secure the blaæe assembly 74
to the blade mount 76 and do not project from either the upper
or lower surface of the cutter assembly 58. As best shown in
Fig. 3, the outer flange 84 of the blade mount 76 is threaded
for mounting on the cutter drive assembly 61. As best shown in
- Figs. 2 and 3, rinse water is conducted form the nozzles 65 to
the cutting head 58 through channels 70 in the table 24. Water
from the nozzles 65 flows upward along the side of the cutter
head 58 and onto the blade assembly 74, washing scraps of potato
out through the aperture below the transverse blade 77.
Although this blade assembly 74 produces the complete
helical cutting of the potato, the innermost helical strip cut
by the blade assembly 74 has only the internal radius produced
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i
i by piercing of the potato by the pin 79. As such, this helical
strip is extremely tightly coiled and to some extent is subject
to breakage.
As illustrated in Fig. 15, this problem can be overcome
! by the use of a blade assembly 103 which includes a cutting tube
104 at its center in place of the pin 79 of the blade assembly
74 illustrated in Figs. 7 and 8. The upper end 106 of this tube
is cut off at a 45 degree angle and is sharpened about its
pe~iphery so that it not only penetrates the potato but actually
cuts a cylindrical core from the center of the potato. The
, 10 cutting tube 104 is attached to the mounting plate 107 about
¦ most of' its periphery but is not mounted to the transverse
' blade. The demountable transverse blade 108 is attached to the
J mounting plate 107. The corner 109 of this blade which abutts
¦ the cutting tube 104 is notched to conform tc the periphery of
-, 15 the tube 104. The tube 104 can extend below the level of the horizontal knife without causing breakage of the innermost
helical strip cut by the blade assembly 103, since this strip
has a radius approximately equal to the radius of the cutting
! tube 104.
Breakage of the helical strips can also be reduced by
selection of the proper shape for the slitting knives 111. These
knives 111 extend vertically from the blade assembly 74 and
travel in a circular path as the blade assembly is rotated. It
! has been found that bending the knives 111 such that the radius
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of curvature of each knife 14 is approximately equal to the
radius of the circular path traveled by such knife 111 advanta-
geously reducing the tendency of the helical strips of potato to
break during cutting and handling.
The cutter drive assembly 61 includes a drive tube 86
which is rotatably supported in the cutter support housing 59 by
upper and lower ball bearings 87. The upper end of the drive
tube is threaded to receive the cutter assembly 58 and a seal 88
is positioned between the support housing 59 and drive tube 86
to seal out water from the nozzles 65. A pulley is mounted
adjacent the lower end of the drive tube 86 and is driven by an
electric motor 89 by means of a -toothed belt 91. The cutter
housing 59 and holder 57 are both mounted to the table 24 and
~ are maintained in alignment with an aperture 92 therein by bolts
93 which extend through the base plate 71 of the holder 57 to
engage the housing 59.
A spray shield 94 is mounted to the frame 11 and en-
circles the lower end of the drive tube 86. A tubular chute 96
is mounted to the spray shield and extends upwardly into the
drive tube 86 to a position just beneath the cutter assembly 58.
This chute 96 conducts the strips of helically-cut potato strips
and rinse water away from the cutter assembly 58 and prevents
contact between the helically-cut potato strips and the rotating
; drive tube which otherwise could result in the strips being held
against the walls of the tube by centrifugal force. Any water
which leaks between the drive tube 86 and cute 96-drains to the
-16-
bottom of the drive tube 86 and is caught by the spray shield 94
and drains out through the holes 97 in the bottom of the shield
94.
Referring next to Figs. 1, 3, 4 and 6, -the annular
¦ conveyor 18 surrounds the frame 11. A flanged track 98 is
! 5 attached to the bottom of the conveyor 18 to receive the support
wheels 99 which are rotatably mounted to the frame 11. A drive
chain 100 is also attached to the bottom of the conveyor 18
along a circular path. A conveyor drive motor 101 drives a
sprocket 102 which is positioned to engage the chain 100 and
rotate the conveyor 18.
Although the present apparatus as illustrated in Fig. 1
is shown as including only four plunger units 42 and eutting
units 56, additional plunging units and cutting units 42, 56 may
be spaced about the apparatus. OE course, it is neeessary that
these units be spaced apart by at least one feed cup 22 so that
potatoes can be fed to all cutting units 56.
As illustrated in Figs. 17-23, the loading of potatoes
into the feed cups 22 may be automated. Such automation is
particularly important when a large number of closely spaced
plunger units 42 and cutting units 56 are mounted about the
machine. As shown in Fig. 18 these cutting units may be spaced
with only a single feed cup 22 between them. The automatic feed
mechanism of the present invention includes an annular conveyor
112 which is similar in construction to the conveyor 18 shown ln
Fig. 1. As shown in Figs. 20-23, however, this conveyor 112 is
. , .
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mounted above the level of the feed cups 22 so that potatoes can
be fed to the cups 22 along a downward path. A plurality of
pneumatically operated diverter assemblies 113 are provided at
; positions spaced above the conveyor 112 for diverting potatoes
from the conveyor 112 into the hoppers 114 associated with the
diverter assemblies 113. As shown in Figs. 21 and 23, each
hopper is associated with a pair of chutes 116 which feed the
potatoes past an indexing system 116 which prevents more than
one potato from entering a feed cup 22.
Referring next to Figs. 17 and 20-23, the conveyor 112
is rotatably mounted to the frame 14 and driven in like manner
to the conveyor 18 shown in Fig. 1. The inner and outer walls
117, 118 bounding the annular conveyor 112, however, are fixed
and do not rotate with the conveyor 112.
Each pneumatic diverter assembly 113 is positioned
adjacent a hopper and may be actuated to sweep potatoes off the
conveyor 112 and into an associated hopper 114. The diverter
assembly includes a diverter gate 119 which is pivotably mounted
adjacent the wall 117 by means of a hinge 121. The diverter
gate 119 is moved between a retracted position as illustrated in
Fig. 21 and an advanced position as illustrated in Fig. 23 by
means of a pneumatic actuator 122 and is formed so that, it
conforms to the interior wall 117 which bounds the conveyor 112.
As such, when the gate is in its retracted position, the con-
veyor can circulate potatoes past the retractor diverter gate
119. The pneumatic actuator 122, like the remaining pneumatic
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actuators of the present apparatus are controlled by servo
values which operate in response to electrical signals from the
control system.
In order that potatoes may be swept off the conveyor
112 and into the hopper 114 by the diverter gate 119, an aper-
ture is provided in the wall 118 opposite the diverter gate 119.
A pair of doors 123, 124 are positioned to fill this aperture
and are operated by a second pneumatic actuator 126. The first
I door 123 is pivotably mounted to the wall 118 by means of a
¦ vertically extending hinge 127, while the second door 124 is
hinged along its top. A pin 129 extends upwardly from the first
door and passes through an aperture in a block 131 which is
j mounted to the second door 124. Thus, movement of the second
! door 124 by the pneumatic actuator 126 also results in opening
or closing of the door 123. The pneumatic actuator 122,126 and
The hopper 114 is positioned to receive potatoes di-
verted into it by the diverter gate 119 and conducts the pota-
toes downward to a pair of chutes 132 each of which is vibrated
along its longitudinal axis by a vibrator 133. As illustrated
' in Figs. 19 and 21, each of these cutes is deeply troughed and
'' 20 becomes narrower with increasing distance from the hopper. The
i chute is inclined downwardly away from the hopper 114 to guide
potatoes downward away from the hopper and towards the feed cups
22. Preferably, the chutes 132 are made of sheet metal which
has been formed with an irregular, textured surface such as by
embossing the sheet metal with a pattern of recesses and
19
3.f3L~
prominences. Such a textured surface aids both the movement of
the potatoes along the chute 132 and the alignment of the longi-
, tudinal axis of the potato with the longitudinal axis of the
! chute 132.
The vibrating chute 132 terminates at the mouth of a
descending, funnel shaped vertical chute 134 which ends just
I above the loading position of a feed cup. The chute 132 and the
! vertical chute 134 are not connected. A small gap is provided
between the two chutes 132, 134 such that the vibrating chute
¦ 132 is free to vibrate while the funnel shaped chute remains
stationary.
! An indexing mechanism 116 is positioned near the end of
I each chute 132. As shown in Fig. 18, this indexing mechanism
! 116 includes a tongue 136 which is hinged at one end to a sup-
port arm 137. The tongue is moved between a retractéd position
¦15 as illustrated in Fig. 20 and an advanced position as illus-
trated in Fig. 22 by means of a double acting pneumatic cylinder
138 which is pivotably connected at one end to the tongue 136
and at the other to the support arm 137. The tongue is bent
such that the free end thereof extends generally parallel to the
bottom of the chute 132 when the pneumatic cylinder 138 moves it
~, 20
i into its advanced position as illustrated in Fig. 22. The lower
surface of this free end 139 is generally concave to conform to
, the upper surface of a potato.
il A curved plate 141 is positioned to hang in the funnel
shaped vertical chute 134. This plate is hinged to a support
, 25
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142 so that its concave potato-engaging surface 143 may be
pivoted away from the end of the vibrating chute 132. A coun~
terbalance support arm 144 is connected to the top of the plate
141 and extends away from the end of the chute 132. A weight
146 is threaded onto the counterbalance arm 144 and can be
positioned thereon to bias the concave surface 143 of the plate
142 toward the end of the chute 132.
Potatoes are loaded onto the annular conveyor 112 by
means of a belt type loading conveyor 115. This conveyor is
controlled to load potatoes onto the annular conveyor 112 as
needed to maintain an adequate supply of potatoes.
The automatic loading mechanism is controlled in re-
sponse to three sensors. As shown in Figs. 17 and 20, a pair
first sensors 147 is mounted above the annular conveyor 112 on
a support 148. These sensor each comprises a light source 149
and a light detector 151. The light source 149 and a light
detector 151. The light source 149 emits a beam of light down-
ward onto the surface of the annular conveyor 112, The light
detector 151 is mounted on the arm 148 in position to receive
light reflected from the annular conveyor 112. When potatoes
are not present on the conveyor, the beam emitted by the light
source is reflected back to the light detector. When the con-
veyor is full of potatoes, however, the bean is scattered and
the light senses the absence of the beam.
As shown in Figs. 20-23, the second sensor 152 com-
prises a light source 153 and light detector 154 mounted on
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opposite sides of the two adjacent chutes 132. The light source
153 projects its beams through apertures 156 in the walls of the
chutes 132 which beam is received by the light detector 154
unless blocked by potatoes in the chutes 132. The apertures 156
are of sufficient size that the oscillatory motion of the chutes
132 does not result in periodic interruption of the beam.
As shown in Fig. 18, the third sensor 157 is mounted at
the end of the chute 132. The light source and detector 158,
159 that comprise this detector are mounted on opposite sides of
the chute. The beam projected from the light source 158 to the
detector 159 is positioned at an elevation above the bottom of
the chute such that it will be blocked by a potato moving down
the chute 132 into the funnel shaped vertical chute 134.
The feed system 115 comprises a conveyer 161 which
extends generally tangentially to the annular conveyor 112.
¦ 15 Potatoes are swept from the conveyor 161 out the annuiar con-
veyor 112 by means of a sweep gate which is operated by a two
stage pneumatic cylinder 163 such that it can be moved between a
retracted, closed position, a position in which it extends
completely across the conveyor 161 at an angle, and a position
' 20 in which it extends only partially across the conveyor 161.
In operation, potatoes are circulated past the several
diverter assemblies 113 by the annular conveyor 112. During
this circulation, the first sensor 147 monitors the supply of
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potatoes on the annular conveyor 112. When no potatoes are
detected by either of the sensors 147 the cylinder 163 is ener-
gized to fully open the sweep gate 162 to load potatoes onto the
conveyor 112. If potatoes are not present under only one of the
sensors 147, the pneumatic cylinder 163 is energized only to
open the sweep gate only part way. Since the feed system 115 is
positioned downstream from the sensors 147, potatoes are added
to the conveyor 112 at approximately the location where the
deficiency was detected. Potatoes are loaded onto the conveyor
112 until the sensors 147 detects that an adequate supply of
I 10 potatoes is present, after which the gate is closed. Prefer-
¦ ably, the feed system 115 is energized to supply potatoes only
I when approximately six inches or more of conveyor 112 has passed
j beneath the sensors 147 without detection of a potato.
The several pneumatic diverter assemblies likewise
l 15 operate only as needed to replenish the supply of potatoes in
! the hoppers 114. The diverter assembly 113 operates in response
to the second sensor pair 152. So long as the light beam be-
tween the light source 153 and light detector 154 of this sensor
152 remain blocked by the presence of potatoes in the chutes
132, the diver-ter gate 119 remains in its retracted position
against the inner wall 117. When the light beam between the
source 153 and detector 154 is unblocked, indicating an absence
of potatoes in the hopper 114 and the chutes 132, the pneumatic
' cylinder 121 is energized to advance the diverter gate 119 to
the position illustrated in Figs. 22 and 23. Simultaneously,
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,f,~
the pneumatic actuator 126 is energized to open the doors 123,
124 and admit potatoes into the hopper 114. As soon as the
sensor 152 detects the presence of potatoes in the chutes 132,
the doors are closed and the diverter gate 119 and doors 123,
124 are retracted to the positions shown in Figs. 20 and 21.
As explained above, the chutes 132 are downwardly
inclined and are reciprocated at a high rate by the vibrator
133. The potatoes thus move downward and inward toward the end
of the chute. As illustrated ln Figs. 18-23, the chutes 132
narrow toward their end and the adjacent, interior walls of each
pair of chutes 132 gradually becomes higher. As a result of
this chute 132 configuration and of the vibration imparted by
I the vibrator 133, the longitudinal axis of the potatoes becomes
¦ aligned with the longitudinal axis of the chutes as the potatoes
¦ move toward the indexing system 116.
The indexing system 113 is controlled in response to
the third sensor 157. The function of the index system is to
ensure that only a single potato is deposited in each feed cup
22 and that potatoes are not permitted to enter the funnel
shaped vertical chute 134 when the feed cups 22 are being moved
into position above one of the cutting heads 56 as described
above.
In operation, potatoes are transported to the annular
conveyor 18 by a vibrating conveyor 19. Workers are positioned
about the periphery of the machine to take potatoes from the
conveyor 18 and insert them into the cups 22 mounted on the feed
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s~
table 19. As illustrated in Fig. 9, when the power is turned on
power flows to the control circuit throuyh the fuse Fl. The
machine remains inactive until energized by the pressing of the
start switch P~l. When this switch is pressed, power flows
through the normally closed switch PB2 to the coil of the first
relay CRl causing the contacts CRla to close and bypass the
start switch PB2. The contacts CRSb also close, providing power
to the rest of the circuit. When power is applied, the pneu-
matic cylinders 43 are in their retracted position and the upper
limit switches 49 are therefore closed. Consequently, the
delay-on-operate time delay relay TDRl is energized. In addi-
tion the ratched drive cylinder 29 is retracted and the limit
I switch 34 is closed. The contact of this relay is normally
; closed and thus the energizing of this relay supplies power to
j the energizing line 103 of the delay-on-release time delay relay
TDR2. Voltage is thus applied to the delay-on-operate relay
TDR4 and the bypass relay CR2. When TDR2 energizes, the con-
tacts TDR2a open, releasing the delay-on-operate relay TDR4, the
relay CR2 and the ratchet solenoid valve releases, retracting
the cylinder and closing the limit switch 34. The time delay
relay TDR2 then de-energizes, closing the contacts TDR2a. On
closure of the limit switch 34, the delay-on-operate relay TDR4
is energized and the relay CR2 closes. The energizing of this
relay CR2 bypasses the limit switch 34 maintaining current
through the closed contacts TDR2a. The contacts TDR2b also
close, energizing the delay-on-release time delay relay TDR3.
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This results in the closure of the contacts TDR3a, actuating the
solenoid valve SOL2 which supplies air to the lock cylinder 31.
This cylinder then retracts the latch 38 to free the feed table
19 to rotate.
The time delay relay TDR4 then de-energizes opening the
contacts TDR4a and TDR4b. This supplies current to the ener-
gized line 104 of the delay-on-release time delay relay TDR3. As
a result, the contacts TDR3a close causing the solenoid valve
controlling the ratchet drive cylinder is energized causing the
cylinder to extend. This results in rotation of the ratchet
wheel 36 and feed table 19. As the drive cylinder extends, the
time deiay on TDR3 runs out and the contacts TDR3a open the
solenoid valve SOL2 which controls the lock cylinder 31. The
latch 38 then moves into contact with the edge of the feed table
19. The stroke of the ratchet cylinder 29 continues until it is
fully extended at which time the limit switch 35 closes. This
signals that the feed table 19 has been rotated to bring one of
the teeth 39 into contact with the latch 38 and that cups 22 are
in position above the cutting units 56. Accordingly, when the
limit switch 35 closes, the relay CR3 is energized. The con-
tacts CR3a then close, energizing the plunger cylinder solenoid
valves SOL3-6 which supply compressed air to extend the plunger
cylinders 43. The cylinders 43 then begin to extend, opening
the limit switches 49 and extending the plunger head 47 to each
push a potato from the cups 22 into the holder 57. The fingers
63 in the holder 57 are pushed outward as the potatoes enter the
--26--
tubular bodies 62 and grip the potatoes by their sides, aligning
them vertically and holding them against rotation as shown in
Figs. 10 and 11.
The downward stroke of the cylinders 43 forces the
potatoes into contact with the rotating cutter assemblies 58.
The slitting knives 78 first cut a plurality of concentric
grooves in the potatoes and the potato is then helically sliced
by the transverse blade 77 as shown in Figs. 12 and 13. The
cutting continues until the cylinder reaches full extension at
which time the plunger head 47 has moved down to the level of
the transverse blade 77. The slitting knives 78, which extend
upward past the level of the transverse blade 77 are received in
the concentric grooves 54 in the lower end of the plunger. As
the plunger head moves downward through the holder, the vertical
I grooves 53 in the plunger head 47 receive the fingérs. These
,15 grooves 53 are of sufficient depth to avoid interference with the fingers, which must continue to hold the potato against
I rotation throughout the entire downward stroke of the cylinder
1 43. If the blade assembly of fig. 15 is used, of course, a
' cylindrical core is also cut from the potato as shown in Fig.
16
' 20
Full extension of all of the cylinders 43 also results
in the closing of the lower limit switches 51 and the energ-
- ization of the delay-on-operate time delay relay TDR5. Since
the circuit is not complete until all of the cylinders 43 are
, fully extended, potatoes of different size requiring different
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~%~
cutting times may be simultaneously cut by the apparatus After
a brief delay to allow for completion of the cutting process,
the contacts TDRSa open to de-energize the solenoid valves
SOL3-6, resulting in retraction of the plunger head 47. When
all of the cylinders 43 have retracted, closing the upper limit
switches 49, the cycle commences again with actuation of the
ratchet mechanism 13.
The operation of the device may also be advantageously
monitored and controlled by a conventional programmable
I controller. One such programmable controller which may be used
j 10 is the Texas Instrument 530 programmable controller which is
provided by the industrial systems division of Texas
I Instruments, Inc. of Johnson City, Tennessee. This programmable
¦ controller may be interfaced in a known manner to the various
switches, sensors and servo valves of the apparatus to control
its function.
The Texas Instruments, Inc., model 530 programmable
controller is designed to control machines by stepping through
its program and performing specific functions in response to
various internal pulses which may have a duration, for example,
of one complete program cycle. As such, the computer may re-
peatedly bypass an instruction to energize the servo valve which
controls a cylinder until conditions are satisfied in a preced-
ing instruction and a pulse is sent on an internal control line
.
-28-
to indicate establishment of the desired condition precedent to
operation of the cylinder. As such, the processor in the pro-
grammable controller may examine each instruction and the condi-
I tions precedent for its execution many times per second. This
ensures that all machine functions are carried out on a timely
, 5 basis and that it is not necessary, for example, to wait for the
index table to complete its movement before the next function
can be carried out. Setting up a machine control program to
operate in this manner is well known in the art. For sake of
clarity in explaining the program, the various functions and the
conditions for their execution have been grouped and described
I in conventional flow chart form.
I As illustrated in Fig. 24, the first step 164 is the
¦ initialization of the machine including the setting of timers
¦ for later use. Rotation of the index table is next initiated.
In subsequent sweeps through the program, the programmable
controller will turn off the drive to the index table 19 when it
has completed its indexing as indicated by cam actuated limit
switches (not shower). Once movement of the table is complete,
the vibrator 133 is then turned on and the tongue 136 is re-
'' 20 tracted to allow the feeding of a potato to the feed cup 22. The
programmable controller next executes a step 166 to determine
whether the third sensor positioned at the end of the chute 132
has been unblocked. In repeated passes through the program, the
programmable controller monitors the state of this third sensor
! 157 to determine when the light beam between the source and
-29-
detector pair 158, 159 has been blocked and then unblocked
indicating the passage of a potato through the sensor 157. Also
after the motion of the index table has stopped, the cylinders
43 which operate the plunger 47 are energized to move downward.
At this point 167, a timer is also started in order to set a
maximum transit time for the stroke of the cylinder 43. If the
timer expires before one or more of the plungers reach the
bottom of their stroke, as indicated by closure of the lower
limit switches 51, such plungers are retracted and disabled. In
addition, if any of the third sensors have not been blocked and
unblocked either before this timer expires or before all
cylinders 43 reach the bottom of their stroke, the tongue 153
associated with such sensors is extended and disabled. If both
indexing systems 112 which are supplied by the same hopper 114
are disabled, the diverter assembly 113 serving that hopper 114
is also disabled.
In the next step, all plungers which have not been
retracted and disabled are retracted. Likewise, with respect to
all indexing systems which have not been disabled, the tongues
136 are extended and the vibrators 133 are turned off.
In the next step, 169, if the machine is still
operating and the feed system has not been disabled, the
programmable controller checks for blockage of each of the
second sensors 153.
If any one of the second sensors is not blocked, the
supply of potatoes in the associated hopper has been depleted.
In order to replenish the supply, the diverter gate 119 is
e x t e n d e d a n d t h e d o o r s 1 2 3, 1 2 4 o p e n e d t o
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admit potatoes into the hopper 114. After the sensor 152 has
been blocked for a predetermined period oE time, the diverter
gate is retracted and a short time later the doors 123, 124 are
closed.
During each cycle, the programmable controller also
checks the pair of first sensors for blockage by potatoes. In a
subsequent step 171, if only one oE the sensors is blocked, the
sweep gate 162 is opened part way. If neither sensor is blocked
by potatoes, however, the sweep gate will be fully opened. After
the gate 162 has been opened, the programmable controller moni-
tors the sensors and closes the sweep gate when an adequate
supply of potatoes is detected by blockage of both sensors. The
programmable controller then returns to continue execution of
the program.
Although the present invention may be adapted to the
~5 cutting of other vegetables, it is described herein with par-
i ticular reference to potatoes for illustrative purposes and is
not limited solely to the helical cutting of potatoes.
,20
,
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