Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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This application is a divisional of Canadian Patent Application No.
2,313,777 filed July 12, 2000 for Driving Mechanism for Shaking Tray.
BACKGROUND OF THE INVENTION
This invention relates to an apparatus for causing material to
advance from one stage to the next in a manufacturing process. More
particularly the invention relates to an apparatus for causing particulate
consumables such as potato chips, corn flakes and -particulate non-
consumables such as pieces of scrap metal to advance on a tray from one
stage to the next in the manufacture of a product.
In the manufacture of particulate consumables, conveyors are
required to move the product from one step in the process to the next. If
the cctnsumable is relatively strong such as rice, sugar, salt, it can usually
be moved on conventional vibrating trays but if the product is fragile such
as potato chips and corn flakes, such trays will cause the product to break
into smaller pieces. The smaller the pieces, the less commercially
acceptable the finished product is.
SUMMARY OF THE INVENTION
The driving apparatus of the present invention causes a shaking tray
to reciprocate. There is provision for adjusting the way in which the tray
reciprocates so that the tray can made to reciprocate jerkily or smoothly.
Thus breakable consumables such as those mentioned above can be
caused to advance smoothly on the tray from one stage to the next
in their manufacture and from the final step to the bagging or package-
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ing operation. Minimal breakage of the product occurs while it
is being moved on the tray.
The apparatus of the invention can be broadly desoribed
as a driving apparatus for a shaking tray on which particulate
material advances. One embodiment of the driving apparatus
comprises a cam rotated by a drive shaft and a follower having
a slot formed therein for receipt of the cam. As the cam ro-
tates, it rolls backwards and forwards in the slot and imparts
rotation to the follower. A connecting rod is affixed to the
follower and is rotated thereby. The connecting rod has an
axis of rotation parallel to, but offset from, the axis of
rotation of the drive shaft. A crank is affixed to the con-
necting rod and is operatively connected to the shaking tray
for imparting reciprocating motion to the tray.
A second embodiment of the driving apparatus comprises a
link which is rotated by a drive shaft and which is rotat-
able about an axis offset from the axis of rotation of the
drive shaft. A follower is rotatably mounted to the link and
is caused to rotate by the link as the link is rotated'by the
drive shaft. A connecting rod is affixed to the follower and
is rotated thereby. The connecting rod has an axis of rotation
parallel to, but offset from, the axis of rotation of the
drive shaft. A crank is affixed to the connecting rod and is
operatively connected to the shaking tray for imparting re-
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ciprocating motion to the tray.
DESCRIPTION OF TIiE DRAWINGS
The apparatus of the invention is described with refer-
ence to the accompanying_drawings in which:
Figure 1 is a perspective view of components of the first
embodiment of the driving apparatus of the invention;
Figure 2 is an elevation of the components illustrated in
Figure 1;
Figure 3 is a perspective view, in enlarged scale, of a
portion of the second embodiment of the driving apparatus of
the invention;
Figure 4 is a perspective view, in smaller scale than
that of the preceding Figures, of the driving apparatus
illustrated in Figures 1 and 2 together with a tray which is
reciprocated by the driving apparatus;
Figure 5 is an elevation of the tray;
Figure 6 i.s an end view of the tray;
Figures 7 to 12 are enlarged fragmentary end views of the
components of the first embodiment of the driving apparatus as
the drive shaft rotates;
['igure 13 is a perspective view of a secorid embodiment of,
the driving apparatus of the invention in conjunction with a
number of trays; and
Figure 14 i.s an el.evat.ion of a tray and a portion of the
driving mechanism i.llustrated in F'igure 13.
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Like reference characters refer to like parts through-
out the description of the drawings.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference to Figures 1 and 2, the driving apparatus
of the invention, generally 10, is shown in conjunction with
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a tray 12. The driving apparatus includes a motor 14 which
rotates a drive shaft 16. The shaft is mounted in bearings in
housing 18 and is connected to a rotating driving block or
member 20.
A cam 22 is mounted in bearings on the driving block and
is positioned eccentrically with respect to the axis of ro-
tation 16a-16a of the drive shaft. The cam is accommodated in
a vertically extending slot 24 formed in a driven block or
follower 26.
The follower is affixed to a connecting rod 28. The con-.
necting rod is mounted in bearings in housing 30 and rotates
about an axis, of rotation 28a-28a. That axis is offset from
the axis of rotation 16a-16a of the drive shaft but is par-
allel to it.
A crank 32 is affixed to the connecting rod 28. A wrist
pin 34 is affixed to the crank and is mounted in bearings in
an arm 36. The arm is pivotally connected to tray 12.
With reference to Figure 3, a drive shaft 40 is affixed
to -a rotating driving block or member 42. A link 44 is ro-
tatably mounted in bearings to the block to rotate about axis
44a-44a. The link is also rotatably mounted in bearings to a
driven block or member 50 to rotate about an axis 48a-48a. A
connecting rod 52 is affixed to the follower.
The axis of rotation 44a-44a of the link is offset from
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the axis of rotation of drive shaft 40 and the axia of ro-
tation of the connecting rod 52 is also offset from the axis
of rotation of the drive shaft.
The mechanism illustrated in Figure 3 may be substituted
for the drive shaft 16, block and follower 20 and 26 and the
connecting rod 28 of Figures 1 and 2. Thus, link 44 of Figure
3 substitutes for cam.22 of Figures 1 and 2.
With reference to Figures 4 to 6, the tray has a lower
wall 58 and side walls 60, 62. Arm 36 is pivotally connected
to side wall 60. The lower wall rests on rollers 64 and the
side walls contact side; rollers 66 to ensure that the tray
remains centred within a stationary bed 68 as it reciprocates.
A first conveyor belt 70 carries particulate material to
the tray and deposits it on the lower wall and a second
conveyor belt 72,carries material which discharges from the
tray.
The position of the components of the first embodiment of
the driving mechanism as the connecting rod rotates increment-
ally is illustrated in Figures 7 to 12. In Figure 7 to 11, the
shaft rotates in increments of 45 degrees and in Figure 12, in
an increment of 90 degrees from the previous Figure.
With reference first to Figure 7, the driving block 20 is
shown in the 2:00 o' clock position with respect to drive shaft
16 and the cam 22, being connected to the driving block is
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likewise in the 2:00 o'clock position. The wrist pin 34
rotates about the connecting rod 28 and is shown in the 4:00
o'clock position.
It will be noted in Figure 7 that the axes of the drive
shaft 16, the connecting rod 28, and the wrist pin 34 are all
offset.from each other. It should also be noted that the drive
shaft and connecting rod rotate about their own axes but the
wrist pin does not. The pin is affixed to the crank and does
not rotate about its axes. It does however rotate about the
axis of the connecting rod.
In Figure 8, the drive shaft 16 has rotated clockwise 45
degrees from the position illustrated in Figure 7 and the
driving block 20 has likewise rotated 45 degrees-. The cam has
rolled toward the left in the slot 24 of follower 26 from the
position illustrated in the previous Figure and the wrist pin
34 has rotated about 22 degrees from the position illustrated
in Figure 7.
In Figure 9, driving block 20 has rotated a further 45
degrees and is now in the 4:00 o'clock position. The wrist pin
34 has rotated about 30 degrees from the position illustrated
in the previous Figure and is now in the 7:00 o'clock
position.
In Figure 10 driving block 20 is now in the 6:00 o'clock
position but wrist pin 34 has rotated 90 degrees from the
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position illustrated in the previous Figure. Thus a rotation
of 45 degrees of the drive shaft has caused a 90 degree ro-
tation of the wrist pin.
In.Figure 11, drive shaft 16 has again rotated about 45
degrees and caused a 90 degree rotation of wrist pin 34 but in
Figure 12 the reverse has occurred. Drive shaft 16 has rotated
90 degrees from the position illustrated in the previous Fig-
ure but wrist pin 34 has rotated only about 45 degrees. As the
drive shaft rotates a further 90 degrees from the position
illustrated in Figure 12 to the position illustrated in Figure
7, the wrist pin rotates only about 45 degrees.
Thus rotationof the drive shaft at a unvarying rate
causes a varying rate of rotation of the wrist pin. At times
the wrist pin rotates more slowly and at other times it ro-
tates more quickly. Such uneven movement of the wrist pin
causes the tray to move in a similar manner and such movement
causes particles on the tray to advance when the tray is
moving slowly forward and to remain stationary when it is
jerked backward.
The operation of the drive mechanism may be summarized as
follows. As the drive shaft rotates, so too does the cam. The
cam also rolls backwards and forward in the slot. Such motion
causes the follower to rotate but the rate of rotation of the
follower is irregular because of the offset between the axes
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of the drive and connecting rods. This irregular movement
causes a like movement in the wrist pin.
The irregularity in the movement of the wrist pin can be
altered by adjustment in the spacing between the axes of the
drive and connecting rods and the spacing between. the axes of
the output and wrist pins. Thus if the movement is so violent
or jerky that the particles on the tray are damaged, the spac-
ing can be altered to reduce the jerkiness or violence.
The wrist pin thus rotates relatively slowly in one dir-
ection. then rapidly in the opposite direction and such move-
ment causes the tray to reciprocate rapidlyin one direction
and slowly in the opposite. Such movement will cause part-
iculate material on the tray to move down the tray with little
damage to the material.
With reference to Figures 13 and 14, trays 80, 82 rest on
the upper wall of a bed 84 and slide forward and backward on
t:l-ie bed. Guide rails 86, 88 atid like rai ls. on ttie opposite
sides of the trays prevent the trays from moving laterally.
Particulate tnaterial such as slugs or blanks 90 drop orito the
trays and are deposited in a bin 92. The material discharges
from the bin into a storage container 93.
A dri.ve block 94 is mounted to the lower wall of each
tray. `1'he block has a concave lower wall 96 of t-he same
curvattire as the outer wal.]. of ati oscillating bar 98 wliich
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extends beneath the tray. The bar is accommodated in the
concave space of the block and gravity ensures that the bar
remains in the space as the bar oscillates. The length of the
oscillating bar can be varied according to the number of trays
that are to be attached to it.
A second rotating bar 100 is located beneath the
oscillating bar. A number of spacers 102 interconnect the two
bars and maintain them in a spaced parallel relationship. The
rotating bar 100 is mounted in bearings 104, 106 and is free
to rotate back and forth in the bearings.
As illustrated in Figure 14, the drive block of the tray
merely rests on the oscillating bar. Otherwise it is not
conriected to ttie bar or to the bed. Should it be necessary to
move the tray along the bed, it is simply lifted as at 90a,
moved along the bar and placed between a pair of guide rails
further along the bed. The tray niay also be removed from the
bar altogether without disconnecting it from the bar or the
bed.
The apparatus 108 for producing reciprocation has the
same components as the apparatus illustrated in F'igures 1 and
2. The apparatus has a coupling or arm 110 similar to arm 36
illustrated in those Figures. An eyelet 112 is attached to the
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forward end of the coupling and receives the end of the
oscillating bar. The bar is thus attached to the coupling and
is caused to reciprocate by it but is free to pivot in the
eyelet.
In operation, coupling 110 causes bar 98 to oscillate in
the direction of arrows 114 in Figure 14. That bar is
supported by the rotating bar 100 which rotates first
clockwise then counter-clockwise in the bearings.
Considerable play between the coupling and the
oscillating bar is possible without detrimentally affecting
the shaking operation. For example, the angle between the
longitudinal axes of the coupling and the oscillating bar need
not be 90 degrees but may be somewhat more or less than that.
Where more deviat:ion of the angle is required, a conventional
spherical tie rod can be used to join the two parts.
Thus careful positioning of the components of the bars
and reciprocating mechanism 108 isnot necessary for the the
mechanism to function. Considerable latitude is possible in
the choice of location of the components. As a result less
time is necessary to position the -components than would be the
case if their positions relative to each other had to be
carefully adjusteci.
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It will be understood of course that modifications can be
made in the preferred embodiments illustrated and described
herein without departing from the scope and purview of the
invention as defined in the appended claims.
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