Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
2136499
CONDITIONING ROLLER ASSEMBLY
This invention relates to a conditioning roller assembly of
the type for use in a hay or other forage crop conditioner.
BACKGROUND OF THE INVENTION
Hay conditioners generally include a pair of rollers
mounted in co-extensive parallel relationship for rotation about
respective axes with the crop arranged to pass between the rollers in
a conditioning action.
Each of the rollers carries a plurality of longitudinally
extending angularly spaced flutes which project outwardly from the
surface of the roller. The rollers are spaced by a distance such that
the flutes intermesh generally without contact between the rollers.
The intermeshing of the flutes causes the crop material to be bent as
it passes between the rollers causing a cracking of the waxy surface
of the crop stem.
It is necessary in such rollers to allow one of the rollers,
generally the top roller, to move in a direction to increase the spacing
between the axes of the rollers to accommodate different amounts of
crop material passing between the rollers and to accommodate
obstacles such as stones and sticks which pass through without
damage to the rollers. Generally this movement is provided by
suspending each end of the top roller on a spring biasing system
which allows each end independently to rise and lower in a floating
action.
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In view of the fact that the rollers carry intermeshing
flutes, it is essential to ensure that the rollers are driven in
synchronism at all times including accommodating the lifting
movement whiie synchronism is maintained.
A number of previous designs have been proposed and
manufactured to provide the drive from the first roller to the second
roller to maintain the necessary synchronism. One arrangement
includes a gear box having an input attached to the bottom roller and
an output shaft attached to the top roller. The output shaft includes
universal joints which allows the output shaft to accommodate the up
and down movement of the top roller shaft. The gear box
arrangement is expensive and is of relatively wide width.
An alternative arrangement includes a double chain drive
system. In this system, a drive sprocket on the end of the bottom
roller and two idler sprockets are located in a common plane at right
angle to the axis of the bottom roller at the apexes of a triangle. A
chain wrapped around these three sprockets engages a fourth
sprocket driven by the chain between the drive sprocket and one of
the idler sprockets. A second chain communicates drive from a fifth
sprocket coaxial with and co-rotatable with the fourth sprocket to a
driven sprocket on the end of the top roller. The top roller is then
positioned within the apexes defining the triangle and can pivot
relative to the axis of the fourth and fifth sprocket. This arrangement
is highly complex involving a high number of idler sprockets thus
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increasing cost and increasing chain wear. The double chain
arrangement also significantly increases the width of the device since
it must accommodate the two chains side by side.
SUMMARY OF THE INVENTION
It is one object of the present invention, therefore, to
provide an improved drive system for conditioning rollers which
accommodates the necessity for a synchronous drive between the
rollers and reduces the number of sprockets and at the same time
minimizes the width of the drive system. It will of course be
10 appreciated that, in order to maximize the width of the rollers, the
drive system should be minimized in width within a predetermined
machine size.
According to one aspect of the invention there is
provided a conditioning roller assembly for a hay conditioner
15 comprising a first roller and a second roller, each roller having thereon
means defining a plurality of flutes extending longitudinally thereof at
angularly spaced positions therearound, means mounting the rollers in
generally parallel relationship each for rotation about its respective
axis at spaced positions defining a spacing between the axes such
20 that the flutes of the first roller intermesh with the flutes of the
second roller as the rollers rotate, the rollers being substantially
coextensive such that a first end of the first roller lies adjacent a first
end of the second roller and a second end of the first roller lies
adjacent a second end of the second roller, said mounting means
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mounting the rollers for first relative movement between the first ends
and for second relative movement between the second ends with said
first and second movements being independent and each in a
direction to increase or decrease said spacing between the axes, drive
5 means for driving rotation of the first roller, and drive communication
means for synchronously driving rotation of the second roller from the
first roller, said drive communication means comprising a first drive
sprocket mounted on the first roller at said first end thereof, a second
driven sprocket mounted on the second roller at said first end thereof,
10 first and second idler sprockets axially aligned with said first and
second sprockets and a chain wrapped around said first and second
sprockets and around said first and second idler sprockets for
communicating drive from the first drive sprocket to the second
driven sprocket, the first drive sprocket and the first and second idler
15 sprockets being located respectively at three apexes of a triangle, the
second driven sprocket being located within the triangle such that the
chain wraps from the first idler sprocket at one apex around the
triangle to the first drive sprocket, around the first drive sprocket at a
second apex, extends from said first drive sprocket inwardly into the
20 triangle to the second driven sprocket, wraps around the second
driven sprocket and extends from the second driven sprocket
outwardly relative to the triangle to said second idler sprocket at a
third apex and wraps around the second idler sprocket and returns to
the first idler sprocket, said mounting means mounting the second
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roller and the second driven sprocket for pivotal movement of said
second axis in an arc within the triangle about a pivot axis generally
parallel to said first and second axes and located at a position such
that a distance of the position from a closest portion of a periphery of
5 the second idler sprocket is substantially equal to a closest portion of
a periphery of the first drive sprocket, such that said pivotal
movement provides said first relative movement while said chain
remains substantially in constant tension and said first ends of the
first and second rollers remain substantially in angular driving
1 0 synchronism.
In place of the chain, a double sided timing belt could
also be used and it is stated that the term "chain" herein is intended
to include such an alternative.
One embodiment of the invention will now be described
15 in conjunction with the accompanying drawings in which:
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is schematic rear elevational view of a
conditioner roller assembly according to the present invention.
Figure 2 is an end elevational view of the apparatus of
20 Figure 1.
Figure 3 is a schematic end elevational view similar to
that of Figure 2 showing the arrangement of the drive sprockets and
the path of the chain for effecting the synchron.ous drive.
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.
In the drawings like characters of reference indicate
corresponding parts in the different figures.
DETAILED DESCRIPTION
The conditioner rollers assembly shown in Figures 1 and
2 comprises a bottom roller 10 and a top roller 11 with respective
axes 12 and 13 which are arranged substantially parallel. The rollers
are substantially coextensive so that each includes first ends 14 and
second ends 15 which are arranged in overlying relationship. Each of
the rollers carries longitudinally extending flutes 16 which extend
along the full length of each roller at angularly spaced positions
therearound. For convenience of illustration, the flutes are shown
only schematically in Figure 1 and only a limited number of the flutes
are shown in Figure 2. It will of course be appreciated that the flutes
extend all around the roller. The flutes are generally formed by
square or rectangular bars which are welded onto the outer surface of
the roller so as to project radially outwardly from the surface of the
roller for intermeshing as shown best in Figure 2. Although shown
directly longitudinal, in most cases the bars or flutes are arranged in a
shallow helix around the cylindrical surface of the roller.
Each of the rollers is fixed to a support shaft so that the
bottom roller 10 is mounted on a support shaft 17 and the top roller
11 is mounted on a support shaft 18. The shaft 17 of the bottom
roller 10 is mounted in bearings 19 carried in end plates 20 and 21 at
respective ends of the rollers. The roller 10 is thus in fixed position
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relative to the end plates 20 and 21 which are in turn carried on a
suitable frame system for the conditioner which is not shown for
convenience of illustration.
The shaft 18 of the top roller 11 passes through slots 22
5 in the end plates 20 and 21 allowing the shaft to move upwardly and
downwardly relative to the roller 10 thus increasing or decreasing
distance between the axes 12 and 13. The shaft 18 is carried at
each end on a respective one of two levers 23 and 24 by bearings 25
mounted on the lever. Each of the levers 23 and 24 is pivotal about a
10 shaft 26 mounted on the end plate parallel to the shaft 18 at a
position spaced rearwardly from the shaft 18. The lever thus extends
from the pivot shaft 26 to the shaft 18 and beyond the shaft 18 to a
forward end 27 at which is provided a suitable biasing system to
provide a downward force on the lever pressing the lever and
15 therefore the roller 11 downwardly toward the roller 10. In the
embodiment shown, the biasing system comprises a spring 28
extending from a mounting pin 29 on the end plate 21 to the lever
23. An adjustable stop member 30 is mounted on the end plate to
limit the downward movement of the lever 23. In the closest position
20 of approach of the roller 11 toward the roller 10 a slight spacing is
maintained so as to prevent the flutes engaging the surface of the
opposed roller. The stop 30 can be adjusted upwardly so as to
increase the spacing between the rollers in conditions where this is
required .
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The bottom roller 10 is driven at the end 14 by a
sprocket 32 driven by a chain or other drive element from a suitable
drive source 33 on the machine. Thus the bottom roller 10 is driven
at a required rate of rotation which can be adjustable if required.
The present invention relates to the drive system for
synchronously driving the top roller 11 from the bottom roller 10.
This arrangement is provided at the right hand end 15 of the rollers
adjacent the end plate 21 and is shown schematically in Figure 2 and
more detail of the location of the various sprockets is shown in Figure
3.
The drive system therefore comprises a drive sprocket
40 carried on the shaft 17 of the bottom roller 11. A driven sprocket
41 is mounted on the shaft 18 for driving the shaft 18. The system
further includes a pair of idler sprockets 42 and 43 each mounted on
a respective shaft 44, 45 carried on the end plate 21. The drive
sprocket 40, the driven sprocket 41, the idler sprocket 42 and the
idler sprocket 43 are all mounted in a common plane parallel to the
end plate 21. A chain 46 wraps around the sprockets for effecting
communication of drive from the drive sprocket 40 to the driven
sprocket 41.
The sprocket 40 includes an axis Iying on the axis 12 of
the shaft 17. The sprocket 41 includes an axis Iying on the axis 13
of the shaft 18. The sprocket 42 includes an axis 47 and the
sprocket 43 includes an axis 48. The axes 12, 47 and 48 are
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_
arranged at apexes of a triangle. The sprocket 41 is positioned within
the triangle so that the chain extends around the first idler sprocket
42 along one side of the triangle to the drive sprocket 40 around the
drive sprocket 40 into the triangle, wraps around the driven sprocket
5 41 and extends therefrom outwardly toward the side of the triangle at
the second idler sprocket 43 positioned at the apex 48. From the
second idler sprocket 43, the chain extends along one side of the
triangle back to the initial position at the idler sprocket 42.
The pivot pin 26 of the lever 23 is located at an axis 49.
Thus the axis 13 of the driven sprocket 41 can pivot on the lever 23
about an arc 50 around the axis 49. Two extreme positions of the
movement are shown in Figure 3. This movement, as previously
explained, increases the spacing between the rollers 10 and 11 to
accommodate the required movement for passage therebetween of
the crop material.
The axis 49 of the pin 26 is located at a position such
that a distance D of the axis 49 from the periphery of the idler
sprocket 43 is equal to a distance E of the axis 49 from the periphery
of the drive sprocket 40. The distances D and E are measured along
a line joining the axis 49 to the axis 12 and the axis 48 so that the
distances D and E are equal to the distance of closest approach of the
periphery of the sprockets. In a circumstance where the drive
sprocket is equal in diameter to the idler sprocket 43, the distances of
the axis 49 from the axes 12 and 48 would indeed be equal. In an
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arrangement as shown, however, the idler sprocket is of slightly
reduced diameter for purposes of manufacturing convenience and
cost.
The position of the axis 49 along the imaginary line
which is equi-distant from the periphery of each of the sprockets 40
and 43 is selected relative to the length of the lever between the axis
49 and the axis 13 so that the amount of movement of the sprocket
41 can be maximized. Thus in the two extreme positions shown in
Figure 3, the sprocket is positioned so that it is relatively symmetrical
in its approach to the sprocket 40 and the length of the chain on the
side of the triangle. As the arrangement is symmetrical, in the
opposed position that is the position of maximum spacing of the roller
11 from the roller 10, again the periphery of the driven sprocket 41 is
symmetrical or equidistantly spaced from the periphery of the idler
sprocket 43 and from the length of the chain along the side of the
triangle.
In the arrangement as shown, this maximizing of the
amount of movement locates the axis 49 at a position just outside a
line interconnecting the axis 12 and 48.
With these positions of the axes of the sprockets and the
pivot axis 49, movement of the axis 13 between the extreme
positions as shown maintains the chain path length of constant length
so that there is no necessity to take up changes in length in the
chain; In addition the movement as shown maintains the ends 15 of
2136~99
the rollers in proper synchronism. This synchronism is required since
it is essential to maintain the flutes in mesh even when that end of
the roller is moved sufficiently apart to separate the in-mesh
arrangement. In such movements the other end of the rollers may
5 remain in mesh and in any event it is necessary of course to keep the
rollers in synchronism when they are fully separated so that when
they return to the meshing arrangement the flutes properly intermesh.
It is also important to maintain constant rotation speed of the top
roller as it moves through the axis 13 since otherwise a change in
10 speed would cause high acceleration and deceleration of the rollers
thus inducing high loads in the chain.
For the purposes of showing the effect on the chain of
the movement of the axis 13 from the first position 1 3A to the
second position 13B, a length of chain is selected extending from a
15 position F on the sprocket 40 to a position G on the sprocket 41.
This same length of chain extends from the position F on the sprocket
40 to the position H on the sprocket 41 when moved to the axis
position 13B. An imaginary line L is drawn from the axis 13 to the
position G and a second imaginary line L1 is drawn from the axis 13B
20 to the position H. It will be noted that these lines are approximately
parallel showing substantially no change in the angular orientation of
the sprocket 41 as it moves from the axis position 13A to the axis
position 13B.
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The pivotal movement of the axis 13 from the position
13A to the position 13~ through the arc 50 maintains the chain at a
substantially constant length so that it is under substantially constant
tension. Again the movement is not exactly that required to maintain
5 the chain path length constant but the minor deviation is insufficient
to cause slackening of the chain or stuttering of the motion.
Adjustment of the path length around the sprockets to
accommodate changes in chain length caused by stretching or
replacement is effected by moving the idler sprocket 43 in the
10 direction of the arrow 60 which is substantially at right angles to the
line joining the axes 12 and 48. Movement in this direction minimizes
variation in the lengths D and E so that these lengths remain
substantially equal to obtain the movement of the sprocket 41 as
described above.
Since various modifications can be made in my invention
as herein above described, and many apparently widely different
embodiments of same made within the spirit and scope of the claims
without departing from such spirit and scope, it is intended that all
matter contained in the accompanying specification shall be
20 interpreted as illustrative only and not in a limiting sense.
