Note: Descriptions are shown in the official language in which they were submitted.
TITLE
[0001] Adjustable Gap Gravity Grader
FIELD
[0002] The adjustable gap gravity grader described was developed for the
purpose of
grading different sizes of fish, but can be used for grading other things
based upon size, such
as fruit or ball bearings.
BACKGROUND
[0003] A gravity grader is used to separate product based upon size. The
gravity grader
consists of series of bars with gaps between the bars and a series of
underlying collectors.
Product moves along the gravity grader from a first end to second end. The
size of the gaps
increase from the first end toward the second end. In operation, a relatively
small product of
a first size will drop by force of gravity through relatively small gaps at a
first end into a first
collector, while relatively larger product continues to move along the bars to
the next
separation section. A next size of product of a second size will drop by force
of gravity
through the gaps, where the size of the gaps have increased, into a second
collector, while
relatively larger product continues to move along the bars.
[0004] It will be appreciated that a single gravity grader may be used to
perform multiple
grade separations or a series of gravity graders may be used in series, with
each gravity
grader having a different separation gap. It will also be appreciated that
there can be any
number of separation gaps with associated collectors, depending upon the
number of grades
desired.
[0005] Although gravity graders originally had fixed bar spacing, gravity
graders are
now available that allow the gaps between the bars in each separation section
to be adjusted
with screw adjustments. It is this ability to adjust the gaps that is the
focus of this patent.
SUMMARY
[0006] There is provided an adjustable gap gravity grader which consists
of a support
frame and a movable carriage. A plurality of bars are supported in parallel
spaced relation by
the support frame with gaps between each of the plurality of bars. Each of the
plurality of
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bars has a longitudinal axis. The plurality of bars are fixed against
longitudinal movement
along the support frame in a direction defined by the longitudinal axis, while
remaining
laterally movable along the support frame toward and away from each other.
Each of the
plurality of bars having either a cam follower or a slotted cam plate. There
is mounted to the
carriage another of the cam follower or the slotted cam plate, such that each
cam follower is
engaged with one slotted cam plate. Movement of the carriage relative to the
support frame
causes relative movement of the cam follower and the slotted cam plate with
which the cam
follower is engaged. The cam follower follows a path defined by the slotted
cam plate,
thereby moving each of the plurality of bars laterally in unison and altering
the size of the
gaps between each of the plurality of bars.
[0007] In the description which follows each of the plurality of bars has two
cam followers
and the slotted cam plate for each one of the plurality of bars is mounted to
the carriage.
Movement of the carriage causes each slotted cam plate to move along the
longitudinal axis
of one of the plurality of bars with the cam followers following the slots in
the slotted cam
plates. It will be appreciated, however, that the positioning of the cam
follower and the
slotted cam plate could be reversed, with the slotted cam plate mounted to the
plurality of
bars and the cam follower mounted to the carriage.
[0008] There are various ways in which the plurality of bars may be
mechanically fixed
against longitudinal movement along the support frame in a direction defined
by the
longitudinal axis, while remaining laterally movable along the support frame
toward and
away from each other. One way will hereinafter be described with respect to a
first
embodiment and another way will be described in relation to the second
embodiment.
[0009] The bars can have various shapes and configurations. One shape and
configuration
will be described with respect to the first embodiment and another shape and
configuration
will be described in relation to the third embodiment.
[0010] It will be appreciated that the above described adjustable gap gravity
grader, provides
for greater ease of adjustment as compared to screw adjustment systems and
provides other
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advantages that will be hereinafter further described.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] These and other features will become more apparent from the
following
description in which reference is made to the appended drawings, the drawings
are for the
purpose of illustration only and are not intended to be in any way limiting,
wherein:
[0012] FIG. 1 is a top perspective view of an adjustable gap gravity
grader.
[0013] FIG. 2 is a side elevation view of the adjustable gap gravity
grader of FIG. 1 in a
first adjustment position.
[0014] FIG. 2A is a perspective view, in section, taken along section lines
2A-2A of FIG.
2.
[0015] FIG. 3 is a side elevation view of the adjustable gap gravity
grader of FIG. 1, in a
second adjustment position.
[0016] FIG. 3A is a perspective view, in section, taken along section
lines 3A-3A of
FIG. 3.
[0017] FIG. 4 is an exploded bottom perspective view of the adjustable
gap gravity
grader of FIG. 1.
[0018] FIG. 4A is detailed perspective view taken from FIG. 4.
[0019] FIG. 5 is a top plan view of the adjustable gap gravity grader of
FIG. 1.
[0020] FIG. 6 is a front elevation view, in section, of the adjustable gap
gravity grader of
FIG. 5.
[0021] FIG. 6A is detailed section view taken from FIG. 6.
[0022] FIG. 7 is a bottom plan view of the adjustable gap gravity grader
of FIG. 1, in a
first position.
[0023] FIG. 7A is a detailed bottom plan view of the adjustable gap gravity
grader of
FIG. 7.
[0024] FIG. 8 is an exploded top perspective view of the adjustable gap
gravity grader of
FIG. 1.
[0025] FIG. 8A is detailed perspective view taken from FIG. 8.
[0026] FIG. 9 is a bottom plan view of the adjustable gap gravity grader of
FIG. 1, in a
second position.
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[0027] FIG. 9A is a detailed bottom plan view taken from grader of FIG.
9.
[0028] FIG. 10 is a top perspective view of a second embodiment of
adjustable gap
gravity grader.
[0029] FIG. 11 is a perspective view, in section, of the second
embodiment of adjustable
gap gravity grader of FIG. 10.
[0030] FIG. 11A is a detailed section view from FIG. 11.
[0031] FIG. 12 is an exploded perspective view of the second embodiment
of adjustable
gap gravity grader of FIG. 10.
[0032] FIG. 13 is a front elevation view, in section, of the second
embodiment of
adjustable gap gravity grader of FIG. 10.
[0033] FIG. 13A is detailed section view taken from FIG. 13.
[0034] FIG. 14 is a top perspective view of a third embodiment of
adjustable gap gravity
grader.
[0035] FIG. 15 is an exploded bottom perspective view of the third
embodiment of
adjustable gap gravity grader of FIG. 14.
DETAILED DESCRIPTION
[0036] A first embodiment of adjustable gap gravity grader, generally
identified by
reference numeral 10, will now be described with reference to FIG. 1 through
FIG. 9A. A
second embodiment of adjustable gap gravity grader, generally identified by
reference
numeral 100, will then be described with reference to FIG. 10 through FIG.
13A. A third
embodiment of adjustable gap gravity grader, generally identified by reference
numeral 200,
will then be described with reference to FIG. 14 and FIG. 15.
Structure and Relationship of Parts:
[0037] Referring to FIG. 1, adjustable gap gravity grader 10 consists of
a support frame
12. A plurality of bars 16 are supported in parallel spaced relation by
support frame 12 with
gaps 18 between each of plurality of bars 16. Each of plurality of bars 16 has
a longitudinal
axis 20.
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[0038] Referring to FIG. 6 and FIG. 6A, each of plurality of bars 16 are
fixed against
longitudinal movement along support frame 12 in a direction defined by
longitudinal axis 20,
while remaining laterally movable along support frame 12 toward and away from
each other.
This is accomplished by connecting each of plurality of bars 16 to guide
sleeves 22 and
.. having a lateral guide pipe 24 forming a portion of support frame 12.
Lateral guide pipe 24
extends through each guide sleeve 22. The engagement between guide sleeve 22
and lateral
guide pipe 24 prevents movement of each of plurality of bars 16 along
longitudinal axis 20.
However, each guide sleeve 22 remains capable of sliding laterally along
lateral guide pipe
24. FIG. 4A provides an exploded view of guide sleeves 22 and lateral guide
pipe 24.
[0039] Referring to FIG. 4 there is provided a movable carriage 14.
Referring to FIG.
2A and FIG. 3A, movable carriage 14 is supported, in part, by lateral pipe
guide 24 of
support frame 12. Referring to FIG. 4, movable carriage has side rails 28.
Support frame 12
has tubular sleeves 26 that receive the side rails 28 of movable carriage 14.
When carriage
14 moves, side rails 28 of movable carriage 14 slide through tubular sleeves
26 of support
frame 12. This relationship can be seen in FIG. 7A, FIG. 8A and FIG. 9A.
[0040] Referring to FIG. 8A, mounted to carriage 14 is a plurality of
slotted cam plates
32. Referring to FIG. 6A each of the plurality of bars has a first cam
follower 30A and a
second cam follower 30B. Referring to FIG. 8A, each slotted cam plate 32 has a
first cam
slot 33A that engages first cam follower 30A and a second cam slot 33B that
engages second
cam follower 30B. First cam slot 33A is longitudinal to accommodate
longitudinal
movement of first cam follower 30A. Second cam slot 33B is angled to impart a
lateral force
through second cam follower 30B to each of plurality of bars 16.
[0041] Referring to FIG. 1, movement is imparted to carriage 14 by a hand
operated
screw mechanism 34. It will be appreciated that a motor driven mechanism could
be
substituted, as long as means is provided to selectively move carriage 14 in
order to move
slotted cam plates 32 toward and away from first cam follower 30A and second
cam follower
30B.
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Operation:
[0042] Referring to FIG. 1, hand operated screw mechanism 34 is used to
selectively
move carriage 14 relative to support frame 12. Referring to FIG. 9 and FIG.
9A, carriage 14
is capable of movement as side rails 28 of movable carriage 14 slide through
tubular sleeves
26 of support frame 12. Referring to FIG. 6A, FIG. 8A and FIG. 9A, movement of
carriage
14 causes relative movement of first cam follower 30A and second cam follower
30B and
slotted cam plate 32 with which first cam follower 30A and second cam follower
30B are
engaged. First cam follower 30A follows a path defined by first cam slot 33A
of slotted cam
plate 32, with first cam slot 33A being longitudinal to accommodate
longitudinal movement
of first cam follower 30A. Second cam follower 30B follows a path defined by
second cam
slot 33B of slotted cam plate 32, with second cam slot 33B being angled to
impart a lateral
force through second cam follower 30B to each of plurality of bars 16.
Referring to FIG. 6
and FIG. 6A, lateral guide pipe 24 extending through guides sleeves 22
prevents movement
.. of each of plurality of bars 16 along longitudinal axis 20, so movement can
only occur with
guide sleeves 22 sliding laterally along lateral guide pipe 24. Referring to
FIG. 2A and
through FIG. 3A, this results in each of plurality of bars 16 moving laterally
in unison and
altering the size of gaps 18 between each of plurality of bars 16.
Variations:
[0043] There will now be described certain aspects of second embodiment
100. Those
elements of second embodiment 100 that do not differ from first embodiment 10
will not be
described in detail and will be assigned the same reference numerals.
[0044] An important aspect of adjustable gap gravity grader is that the
plurality of bars
are fixed against longitudinal movement along the support frame in a direction
defined by the
longitudinal axis, while remaining laterally movable along the support frame
toward and
away from each other. In first embodiment 10, this was achieved by having a
lateral guide
pipe 24 secured to support frame 12 and a guide sleeve 22 is secured to each
of plurality of
bars 16. Lateral guide pipe 24 extended through each guide sleeve 22 and
restricted
longitudinal movement of each of the plurality of bars 16. However, each guide
sleeve 22
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remained movable laterally along lateral guide pipe 24.
[0045] The
purpose of including second embodiment 100 is to show that this may be
achieved in other ways. Referring to FIG. 10 through 13A, each of plurality of
bars 16 is
connected to a guide plate 122. Each guide plate 122 is confined within a
lateral guide
channel 124 mounted to support frame 12. Guide channel 124 confines and
prevents
movement of each guide plate 122, thereby preventing movement of each of
plurality of bars
16 along longitudinal axis 20. However, each guide plate 122 is capable of
sliding laterally
along lateral guide channel 124.
[0046] There
will now be described certain aspects of third embodiment 200. Those
elements of second embodiment 200 that do not differ from first embodiment 10
will not be
described in detail and will be assigned the same reference numerals.
[0047] In first embodiment 10, each of plurality of bars 16 were
cylindrical. Referring to
FIG. 14, third embodiment 200 has been illustrated to show that plurality of
bars 216 may
take other shapes without adversely effecting function.
[0048]
Referring to FIG.15, another reason third embodiment 200 has been selected for
illustration is that these components have been reversed. In first embodiment
10, cam plates
32 were carried by movable carriage 14 and cam followers 30A and 30B were
carried by bars
16. In third embodiment 200, cam followers are carried by movable carriage 14
and cam
plates 32 are carried by bars 16.
[0049] In first embodiment 10, there was a pair of cam followers; first cam
follower 30A
and a second cam follower 30B. Third embodiment 200 has a single cam follower
30.
[0050] In
first embodiment 10, movable carriage 14 had side rails 28 and support frame
12 had tubular sleeves 26, with side rails 28 of movable carriage sliding
through tubular
sleeves 26 of support frame 12 during movement. In third embodiment, support
frame 12
has side rails 28 and movable carriage 14 has tubular sleeves 126, with
tubular sleeves 126 of
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carriage 14 sliding over side rails 28 of support frame during movement.
[0051] Third
embodiment 200 also helps in demonstrating how bars 16 must travel
different distances. Each bar 16 and cam plate set 32 has an increasingly
larger angle as the
bar position is farther from a central position. The increasing angle provides
an increasing
lateral movement as movable carriage 14 moves longitudinally. Gap opening 18
is equal for
all bars 16 due to the increasing lateral movement of each bar 16 to its
adjacent bar 16.
Advantages:
[0052] The above described adjustable gap gravity grader provides a number
advantages
over adjustable gap gravity graders that have screw type adjustments.
[0053] 1. It
is not uncommon for there to be nine or more parallel bars in an adjustable
gap gravity grader. As an adjustment is made, not all bars move an equal
distance.
Outermost bars must move proportionately farther than inner bars. This makes
for a more
time consuming adjustment to ensure accurate placement, unless outer bars are
equipped
with screws that have a thread pitch that causes more travel than the thread
pitch used for the
inner bars. Having differing thread pitches to achieve this objective of
differing bar
movement is expensive, as it requires custom machining.
[0054] 2.
Lubrication and a protective cover are required in order to keep water and
slime out of screws used to make screw adjustments. This necessitates frequent
and costly
maintenance. The adjustable gap gravity grader described above is less
effected by water and
slime.
[0055] In
this patent document, the word "comprising" is used in its non-limiting sense
to mean that items following the word are included, but items not specifically
mentioned are
not excluded. A reference to an element by the indefinite article "a" does not
exclude the
possibility that more than one of the element is present, unless the context
clearly requires
that there be one and only one of the elements.
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[0056] The scope of the claims should not be limited by the illustrated
embodiments set
forth as examples, but should be given the broadest interpretation consistent
with a purposive
construction of the claims in view of the description as a whole.
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