Note: Descriptions are shown in the official language in which they were submitted.
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BACKG~OUND OF THE INVENTION
The present invention relates generally to apparatuses
for cleaning grain and more particularly to gravity-fed apparatuses
employing screens without having external vibrating means.
The notion of separating fines from clean grain by
gravity feeding the material to be screened through a zig-zag
path with the underside of each zig and each zag being a screen
has long been recognized in the art, as is evidenced. for example,
by U.S. Patent Nos. 1,16~,282, issued January 18, 1916
(Burgeson); U.S. Patent 1,173,249, issued February 29, 1916
(Burgeson); U.S. Patent 1,185,595, issued ~ay 30, 1916
(Daly); U.S. Patent 1,945,242, issued January 30, 1934
(Walker) and U.S. Patent 2,203,152, issued June 4, 1940
(Johnson). While generally satisfactorily accomplishing
their goal without the need for moving parts and accompanying
machinery, such screeners had the common disadvantage of shortly
becoming clogged with material such as broken pieces of grain
without affording efficient and simple access to their interiors
for cleaning, replacing screens and general maintenance. Hence,
other configuratlons of screens which are mechanically vibrated
or powered rotary screeners which tumble the material to be
screened are frequently employed. By maintaining the grain or
other material to be screened in a constant state of agitation,
; the clogging tendency is greatly reduced. While screens thus
employed do not clog as quickly, a more complex and expensive
piece of equipment is req~ired, the separating action is less
efficient and screen rep,lacement is still somewhat difficult.
A rather popular type of gravity feeder which offers
a solution to the screen cleaning and replacement dilemma, is
in the form of a large gem having a silhouette in the shape
of a diamond. The bottom half of the diamond is in the form
of a large funnel having a square cross-section. The upper half
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of the diamond is identically shaped, but inverted, and has
a smaller similarly shaped structure of screen material within
it which is spaced away from its inner surfaces. This screen
structure is connected at its bottom to a smaller solid walled
lower half of what completes an interior diamond-silhouette
structure, the bottom half of which is also spaced away from
the bottom half of the exterior diamond-silhouette structure.
The inverted funnel shaped screen is not open at its top and
when grain enters at the top of the larger exterior structure,
fines passing through the screen are caught by the interior
lower solid wall structure and discharged through its bottom.
Clean grain travels between the interior diamond-silhouette
structure and the exterior diamond-silhouette structure through
a discharge in the bottom thereof.
Such gravity-fed cleaners typically have, at their
mid-sections, a square cross-section with sides 10 feet or longer
in length. The smaller more compact gravity fed grain cleaners
of the zig-zag chute type handle equivalent flow rates to those
of the large diamond-silhouette type, primarily due to the in-
creased agitation of the grain each time its flow path is abruptly
altered by 90. However, the diamond-silhouette type of grav-
ity-fed grain cleaner is, of necessity, large enough a~size
that access to its interior structures for cleaning and replacing
screens does not present a nearly impossible situation.
Nevertheless, a great deal more screen material and
casing material is required to build the diamond-silhouette
style grain cleaner than would be for prior art zig-zag cleaners
and replacing screens is generally still a two man job requiring
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everal hours of ùifficult labor. The present invention provides
a cleaner which is materially more efficient than prior art
zig-zag cleaners and, at the same time allows access for rapid
screen replacement.
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SUMMARY OF THE INVENTION
In the apparatus of this invention a casing is provided
which has a central vertical zig-zag chute formed within it
for receiving the gravity fed material to be screened. Screens
are hinged above and cover opening~ on the underside of each
zig and each zag of the chute. Cleaning or replacing screens
is made simple by a large access door on the front wall of the
casing and by the simple construction of the screens and the
manner in which they are hinged above the openings. Each screen
has a narrow top strip bent at 90 along one horizontal edge
which is used to support the screen within an open-ended slot
at the knee of each zig and zag. Thus, with the access door
open, all screens may be removed and replaced in less than ten
minutes by one person.
Also, greatly enhancing its efficiency as compared
with the prior art gravity-fed zig-zag grain cleaners is the
affect of the resonating action of each screen as it floats
in a more or less hinged fashion about its supporting slot and
above the underside of the zig or zag over which it is positioned.
This floating and resanating action ~sl itself, a result of
the effect of the bombardment of the many particles of grain
as they pass through the zig-zag chute. This non-mechanically
produced vibratory action of each screen enables the present
invention to clean a materially greater flow of grain than prior
¦art zig-zag chute cleaners. The present invention is capable
of independently cleaning grain or the like, or being installed
within a gravity flow system such as a commercial elevator,
¦¦a termlnal vator for export shlpplng, a feed mlll, or a food
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processing facility.
An object of the present invention is the provision
of a zig-zag chute grain cleaner which agitates its screens
without moving parts for enhancing its efficiency and for enabling
its screens to self-clean.
Another object is to provide a grain cleaner in which
screens may be quickly replaced by a single person.
A further object of the invention is the provision
of a grain cleaner flow regulator with a cleaner by-pass for
the avoidance of upstream jamming when the flow of grain exceeds
its designed rate.
Still another object is to provide a gravity-fed grain
cleaner, having access to its interior, of smaller size, lesser
quantities of material, and lesser weight than prior cleaners.
A still further object is to provide total access
to the interior of the casing of a gravity-fed grain cleaner
from one side for inspecting, servicing and screen changing.
Yet another object of the invention is the provision
of a light weight grain cleaner which requires less supporting
structure for installation within gravity-fed systems.
Yet a further ob;ect is to provide an upright rectangu-
lar prism-shaped grain cleaner which is more compact an'd suitable
for installatlon in tight spaces.
An additional object is the provision of a grain cleaner
which can be a standard inventory unit for handling a variety
of commodities requiring different pre-set flow rates which
can be combined with other units for multiple installations
or aomp nts of other gravity-fed systems.
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These and other objects, advantages, and novel features
of the present invention will become apparent from the following
detailed description of the invention when considered in conjunc-
S tion with the accompanying drawings.
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DESCRIPTION OF THE DRAWINGS
Fig, 1 is a front cross-sectional view of the apparatus I
installed in a gravity-flow system, other components thereof
shown in phantom lines, taken along lines 1-1 of Fig. 2;
Fig. 2 is an enlarged front perspective view of the
casing portion of the apparatus with a broken view into one
side and with the access door open for a view into its interior;
and
Fig. 3 is a super-enlarged partial cross-sectional
view of the casing, zig-zag chute and by-pass of the apparatus,
showing grain flowing therethrough, taken along line 3-3 of
Fig. 2,
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~ESC~IPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings wherein like reference
numerals designate identical or corresponding parts throughout
the several views, and more particularly to Fig. 1, whereon
S my apparatus for screening grain and the like 100 is designated
generally at 10, its major components are a casing 20, a zig-zag
chute 30, a plurality of resonating screen mechanisms 40 for
separating clean material from rines, flow regulator So, a receiv l
ing hopper 60, a by-pass 70, a delivery chute 80 and a coarse
screen 90. Phantom lines above and below apparatus 10 in Fig.
1 indicate feed and discharge elements of any of various con- ¦
ventional gravity flow systems within which my apparatus 10
may be installed. Formed within casing 20 are chute 30, screen
mechanisms 40, regulator 50 and hopper 60 to comprise a basic
unitized cleaning apparatus. As casing 20 is of the general
shape of an upright rectangular prism, this portion of the appara-
tus is useful as a standard inventory item for the manufacturer,
¦being suitable for installation in multiples or with other com-
¦ponents tailored to be joined with it. Flow regulator 50 adds
la degree of flexibility for applications for different commo-
¦dities as will be explained later.
¦ Referring now to Fig. 2, casing 20 is seen to be con-
structed of four sheets of elongated rectangular material. One
sheet forms front wall 21 and a sheet of equal size and shape
forms rear wall 22. Connected near the edge of both front wall
21 and rear wall 22, normal thereto, and of equal width are
left side wall 25 and right side wall 24 (see also Fig. 1).
The bottoms of side walls 25 and 24 extend as far as the bottoms
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of front wall 21 and rear wall 22, and the top of left side
wall 23 as far as their tops. The top of right side wall 24
extends to a point somewhat below the top of front wall 21 and
rear wall 22. Front wall 21 has a large elongated rectangular
S opening 25 covering most of its area for access to the interior
of casing 20 and a door 26 capable of o~erably closing in a
well known manner in order to substantially enclose the casing
20 as though there were no opening 25. Furthermore, door 26
has a center portion 27, raised by the same thickness as front
wall 21 and of a size and shape substantially equal to opening
25, whereby the inner surface of wall 21 will be effectively
a single plane when door 26 is closed.
Referring now to Figs. l, 2 and 3, zig-zag chute 30
is comprised, in this embodiment, of four basic units 31 (see
in particular unit 31 in Fig. 2 where a screen is depicted as
having been removed). 8asic unit 31 includes a lower rectangu-
lar element 32 having a horizontal dimension equal to the width
of side walls 23 and 24, and an upper portion 33 of the same
shape and size as lower portion 32 and affixed thereto, normally,
along adjacent horizontal edges. Normal affixation between lower
portion 32 and upper portion 33 is not essential to the functionin
of the apparatus 10, other angles, either shallower or'broader,
also being suitable. Upper element 33 has a centered rectangular
opening 34 dimensioned so as to create a narrow rectangular
screen support out of upper element 33.
Each of the four basic units 31 are mounted inside
of casing 20 along one of their vertical sides to rear wall
22. The juxtaposition of the four basic units 31 within casing
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20 can be readily understood by referring to Fig. l, whereon
they can be seen to form a central vertical zig-zag chute within
casing 20 having a constant cross section, having on the underside
of each of its zigs and zags opening 34, and leaving along the
left outside of two of the opening 34's on one side of zig-zag
chute 30 a clear passageway 28 and along the right outside of
the other two openings 34 a clear passageway 29. Both of the
lower portions 32 on the left side and right side of zig-zag
chute 30 have affixed thereto extension units 36 and 37, respec-
tively, having horizontal dimensions equal to the width of left
and right sides 23 and 24 and appropriately sized and oriented
to direct the clean material 102 discharging from chute 30 to
clean material discharge 38. Fitted around and beneath discharge
38 is fines confluent discharge 29a which interconnects with
lS clear passageways 28 and 29.
In addition, -there is a special unit 39, rectangular
in cross section, having a horizontal dimension equal to the
width of left and right sides 23 and 24 which is mounted along
one of its vertical sides to rear side 22 above the higher basic
unit 31 forming the left side of zig-zag chute 30 at an orientatio~
which will complete the upper zig-zag element of zig-zag chute
30. A slot 41 is functionally formed above each upper portion
54 of each basic unit 31 by leaving a slight space therebetween
and the adjacent structural unit. The adjacent structural unit
is two basic units 31 and simple unit 39 in three instances,
the fourth being a portion of receiving hopper 60 which will
be described below. The purpose of slot 41 will be set forth
in the following paragraphs.
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Referring again to Fig. 2, four resonating screen
mechanisms 40 are each seen to have a screen element 42 which
is rectangular in shape and which has substantially the same
dimensions as upper portion 33 of basic unit 31. As will be
more fully explained later, the size of the openings of screen
elements 42 is such that the clean material 102 of the material
to be screened 101 will remain within chute 30 and the fines
103 passing through screen mechanisms 40 will fall through clear
passageways 28 and 29 to the bottom of casing 20 and then exit
from confluent discharge 29a. Depending normally from one hori-
zontal edge of each screen element 42 is a strip 43 which, in
this embodiment, is formed by a 90 bend in the screen material.
As can be readily appreciated by referrring to Fig. 2, screen
element 42 along with strips 43 may be removably inserted, when
access door 27 is open, into their operating positions by sliding
strips 43 within slots 41.
Screen elements 42 are in their operating positions
hen they are resting flush against upper portions 33 of basic
units 31. In this position, screen elements 42 are free to pivot
pwardly within the interior of chute 30 about the upper horizontal
dges of upper portions 33, being restricted only by the lower
ortions S2 of the adjacent basic units 31. ~lthough it is not
ssential to my concept, it is anticipated that the distance
etween the planes of left and right side basic units 31 will
e less than the heights of upper and lower portions 32 and
4. It should be apparent that this method of hingedly connecting
creen mechanisms 40 within zig-zag chute 30 allows for quick,
asy and efficient removal of screen elements 42 along with
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strips 43, either for changing to different sized screen elements
42, cleaning the screen elements or replacing damaged screen
elements.
. Referring now to both Figs. 1 and 2, flow regulator
S 50 is located immediately above the upper horizontal edges of
simple unit 39 and the highest basic unit 31. Upper and lower
guide plates 51 and s2, respectively, are affixed to the inside
surface of rear wall 22 towards the left side thereof in locations
such as will form a horizontal guide 53 whose bottom is at the
same elevation as the top of simple unit 39 and the top of the
highest basic unit 31. Horizontal slide gate 54 is of the same
width as left and right sides 23 and 24 and is slidably installed
atop of simple unit 39 and guide plate 52. Its thickness is
slightly less than the width of horizontal guide 53 and its
elevation within casing 20 is maintained by guide plate 51.
As my apparatus 10 is suitable for cleaning various
grains having different weight and volume characteristics, it
s anticipated that gate 54 will be pre-set at the factory depend-
ng on what grain or commodity is to be cleaned. Generally,
he other components of the gravity fed system within which
t is connected are also geared to operate at a certain flow
ate, such as 5,000 bushels per hour. Gate 54 would be set to
onstrict the area of the top of zig-zag chute 30 by whatever
mount is required to be in phase with the particular product
o be cleaned.
Referring again to Figs. 1 and 2, receiving hopper
0 is seen to be formed of a left side wall 61 which is primarily
ectangular and, in this embodiment, has a short upwards bend
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of 135. Left side wall 61 has a horizontal dimension equal
to the width of side walls 23 and 24 and the length of its longer
height dimension is approximately equal to the distance from
the top of gate 54 directly above simple unit 39 to a point,
angling upwardly at 45 therefrom, somewhat short of left side
wall 23. The 135 bending portion of left side wall 61 of hopper
60 extends to the top of front and rear walls 21 and 22 when
left wall 61 of hopper 60 is affixed to the inner surfaces of
the front and rear walls 21 and 22 at the location indicated
by the above definition of its height dimensions.
Right side wall 62 of hopper 60 is of essentially
the same configuration as left side wall 61, except that it
is oriented in reverse within casing 20 in order that its 135
bend portion will coincide along its outside surface with the
upper, inner surface of right side wall 24. Its longer height
dimension is equal to a 45 downwardly angling distance to a
oint adjacent to the higher right side basic unit 31. That
point is above said basic unit 31 far enough to allow adequate
width to form a functioning slot 41 therewith. Right side wall
62 is affixed along its vertically oriented edges to front wall
21 and rear wall 22 and along its upwardly bent vertical portion
to the upper, inner surface of right side wall 24. Receiving
hopper 60 is thereby completely formed within casing 20 and
above flow regulator 50.
As explained above, it is anticipated that flow regu-
lator 50 will be factory pre-set for a given flow rate for a
particular application. Any material 101 which accumulates in
hopper 60 when apparatus 10 is charged at a higher rate will
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flow over right side hopper wall 62 and into by-pass 70. By-pass
70 directs overflow material 104 along the outside of casing
20 and long its bottom to where it joins with clean material
discharge 38. sy-pass 70 is formed by an exterior by-pass wall
71 which is spaced away from side wall 23 and parallel thereto,
sloping exterior by-pass top wall 72, sloping exterior by-pass
bottom wall 73, front by-pass side wall 74 (see Fig. 2), rear
by-pass side wall 76 and the outer surface of side wall 23.
These elements are interconnected in a well known manner to
form by-pass 70 which will direct overflow from receiving hopper
60 therethrough to its connection with clean material discharge
38.
It should be apparent that it is possible to construct
confluent fines discharge 29a, clean material dischàge 38 and
by-pass 70 of shapes which will accomplish the required intercon-
nections below casing 20. When the material flow is above the
pre-set rate of gate 54, a small quantity of unscreened material
will by-pass chute 30 through by-pass 70. This alternative is
referable to the usual abuse of upstream components of a gravity
low system when jamming or stuffing occurs. The exterior dimen- ¦
ions of by-pass 70 are such that when added to the right side
f casing 20 its general upright rectangular prism shape is
ot materially altered.
Again referring to Fig. 1 whereon delivery chute 80
s shown in cross section, it is seen to have a single opening
1 at its upper end for receiving gravity fed grain and the
ike 100, a first discharge opening 82 at its lower end for
eeding into receiving hopper 60 materlal to be screened 101,
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',
and a second opening 83 also at its lower end for discharging
large foreign matter 106. In the case of typical farm grain,
foreign matter 106 may include such things as broken glass,
corn cobs, beer cans and rocks.
Delivery chute 80 is inverted funnel-shaped with its
upper opening 81 conformed to match and be connected with the
conventional gravity flow system within which apparatus 10 is
installed. Its first discharge opening 82 has a horizontal linear
configuration which will sealably connect with the rectangle
defined by the upper horizontal edge of hopper left side wall
61, sloping exterior by-pass top wall 72, and the portion of
front and rear walls 21 and 22 contained therewithin. An inclined
upper surface 84 of delivery chute 80 passes above the upper
horizontal edge of hopper left side wall 61 a distance which
defines the front and rear spacing of second discharge opening
B3 (when considered to be oriented face-wise the same a~ casing
20). Upper surface 84 then turns downwards and, along with the
front wall (not shown) and rear wall 86 of delivery chute 80
is extended to complete opening 83. Opening 83 connects with
that portion of the top of casing 20 defined by the upper hori-
zontal edges of left side,25, hopper left wall 61 and the portions
of front wall 21 and rear wall 22 therebetween.
Coarse screen 90 extends through a section of delivery
chute 80 which begins on the left at the conjoinment 91 of first
opening 82 and second opening 83 and continues upwardly and
across delivery chute 80 to a line 92 just below delivery chute
receiving opening 81. Coarse screen 90 is of a size which will
not permit large foreign matter 106 to flow therethrough and
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will permit the material to be screened 101 to enter receiving
hopper 60. Accordingly, large foreign matter 106 will gravity
feed into left clear passageway 28 where it mixes with and is
discharged with fines 104 through confluent discharge 29a.
Having disclosed the structure of the present apparatus
for cleaning grain and the like 100, its functioning will now
be described. Referring to Figs. 1 and 3, arrow 121 shows the
direction of flow of a commodity, such as husked corn, entering
through opening 81 of grain receiving chute 80. Arrow 122 indicate< ,
that large foreign matter 106 will flow into passageway 28 and
arrow 123 shows the material to be screened 101 entering hopper
60. Arrows 124 show the path of clean corn 102 which fails to
pass through any screen 42 flowing through zig-zag chute 30
and, subsequently, out clean material discharge 38. Arrows 126
lS depict the path of fines 103 flowing through screens 42 into
both passageways 28 and 29 and, subsequently, out through fines
confluent discharge 29a. The path of material to be screened
101 which may overflow from receiving hopper 60 through by-pass
70 and, subsequently, beneath casing 20 into clean material
discharge 38 is indicated by arrow 127.
As a consequence ,of the flow of the husked corn, as
in this example, through apparatus 10, screens 42 are caused
to vibrate rapidly above upper portion 33 of basic unit 31 and
about slot 41, thereby further agitating the material to be
screened 101 as it passes from receiving hopper 60. Fines 103
join foreign matter 106 in left passageway 28 and pass on through
fines confluent 29a after having joined with fines exiting from
right passageway 29. In some situations, as explained above,
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a portion of material to be screened 104 will travel through
by-pass 70 through clean material discharge 38, joining clean
corn 102.
l Although many materials which are well known may be
¦ used to fabricate the apparatus 10, a lightweight but strong
unit may be constructed of basic materials universally available.
These materials are angle-iron, 10 gauge steel, high carbon
woven wire, steel strap, and standard nuts and bolts.
l Having hereby disclosed the subject matter of this
l invention, it should be obvious that many modifications, substi-
tutions, and variations of the invention are possible in light
¦of the above teachings. It is therefore to be understood that
¦the invention may be practised other than as specifically de-
¦scribed, and should be limited only by the breadth and scope
¦of the appended Claims.
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