Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02307401 2000-OS-03
TITLE
IMPROVED LOG ELEVATING CONVEYOR
FIELD OF INVENTION
This invention relates generally to a stair type log
conveyor having members that reciprocate and move logs
thereon forward in sequence in increments corresponding to
the forward distance of travel and more particularly to
improvements to the log supporting members and an improved
linkage drive to move such members.
BACKGROUND OF INVENTION
United States Patent 5,374,157,issued Dec.20,1994 to
B. Allard discloses an apparatus for unscrambling and moving
logs up an inclined path. The path has a direction
transverse to the length of the logs and the logs rest in
notches in vertically disposed, parallel, horizontally
spaced apart, plates. In the patented apparatus the logs
have to longer than the spacing between the plates and thus
is limited in that respect. Some of the plates are
interconnected while others are not.
There is debris associated with log conveying that
includes pieces of bark, chips and the like. In the above
patented apparatus this debris falls between the vertically
disposed plates dropping into the drive mechanism below or
alternatively slides down a plate that joins together two
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adjacent plates and accumulates in hard to get at piles at
the front of the apparatus.
SUMMARY OF INVENTION
A principal object of the present invention is to
provide an improved log support surface that will move not
only pieces of various lengths but also short and small
pieces .
A further principal object of the present invention is
to provide a self cleaning log mover that moves the logs
upwardly along an inclined path.
A further principal object is to provide a smooth
operating rigid unit that unscrambles and conveys the logs
in sequence up an inclined path.
In keeping with the forgoing objects there is provided
in accordance with the present invention a log conveyor
comprising a first and second pair of rigid stair flight
units mounted at an incline on a support structure and each
having a series of stair risers and treads, said stair
risers and treads of one unit being disposed in interleaved
overlapping relation with those of the other unit, a
plurality of rocker arms connecting said respective stair
flight units to said support structure for oscillating along
respective arcs off-set a selected distance from one
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another, each said rocker arm being connected at spaced
apart positions to said support frame and the stair unit
associated therewith, and drive means for oscillating said
stair units comprising a linkage system mounted on said
support structure and connected to said respective stair
units to oscillate the same in synchronized 180 degree out
of phase relation.
LIST OF DRAWINGS
The invention is illustrated by way of example in the
accompanying drawing wherein:
Figure 1 is an oblique partial view of applicants
log conveyor;
Figure 2 is a side elevation, part broken away,
view of the apparatus shown in figure 1;
Figure 3 is a side view as in figure 2 but with
less detail and showing the relative position of the two
interleaved stairways and position of the rocker arms and
drive linkages with a log at the beginning of the stairway;
Figure 4 is the same as figure 3 but with the log
moved a portion of one step;
Figure 5 is the as figure 4 at the time of
transfer of the log from one stair of one stair unit to a
stair of the other stair unit;
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Figure 6 is the same as figure 4 but with the log
continuing on the second stair unit; and
Figure 7 is a plan view of the stair mounting
rocker arms, drive linkages and stair mounting stringers.
PREFERRED EMEiUDIMENT
Referring to the drawing there is illustrated a log
conveyor comprising first and second respective rigid stair
flights units 300 and 400 disposed in interleaved
overlapping relation and each mounted on a common rigid
support structure 100 by a plurality of rocker arms and
driven by a linkage system to oscillate in synchronized 180
degree out of phase relation.
The stair flight unit 300 is a rigid assembly
comprising a series of stair risers 301,302,303, and 304
resting on plurality of support members
300A,300B,300C,300D,300E and 300F that project upwardly from
and are carried by a pair of spaced apart cross beams 305
and 306. The stair risers have respective stair treads
301A,302A,303A, and 304A, associated therewith.
The stair flight unit 400 is, like the flight unit 300,
a rigid assembly comprising a series of stair risers
401,402,403,and 404 resting on a plurality of support
members 400A,400B,400C,400D,400E and 400F that project
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upwardly from and are carried by a pair of spaced apart
cross beams 405 and 406.
The support members 300A...300F and 400A...400F are so
positioned as to have the stair risers of unit 300
overlapping and interleaved with the risers of unit 400
leaving sufficient room so as to allow the units to
oscillate 180 degrees out of phase on their respective
rocker arms, to be described hereinafter, without
interfering with one another. The stairway provided by the
two stair units is inclined upwardly and during operation
one of the flights 300 or 400 is moving up while the other
thereof is moving down the incline.
The rigid stair unit 300 is mounted on the frame
structure 300 by a front pair of rocker arms 307,308 and a
rear pair of rocker arms 309 and 310. The rocker arms are
pivotally connected at one end to the support structure 100
and at the other end to the stair unit. The stair unit thus
moves in an arc as it oscillates back and forth.
The rigid stair unit 400 is mounted on the support
frame structure by a front pair of rocker arms 407 and 408
and a rear pair of rocker arms 409 and 410. The rocker arms
are pivotally connected at one end to the support structure
100 and at the other end to the stair unit 400. The pivotal
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connections of the rocker arms are evident from figures 2 to
6 of the drawings.
Each rocker arm is generally "T" shaped and in the
installed position is inverted. Since all of rocker arms are
the same only one will be described in further detail.
Referring to figures 2 and 7 the rocker arm 307 has a stem
307A projecting from a long sleeve 307B with the stem being
reinforced by a pair of webs or gussets 307C and 307D. A
shaft 307E passes through the sleeve 307B and is journalled
therein by a pair of spaced apart tapered roller bearing
units(not shown)and the shaft is securely anchored to the
support structure 100 by a pair of spaced mounting blocks
307F and 3076. A pin 307H is mounted on the stem by a
bearing adjacent the free outer end thereof and that pin is
securely attached to the structure of the rigid unit 300 by
a pair of mounting blocks 307J.
All of the rocker arms 307...310 and 407...410 are the
same length and the two units 300and 400 thus have the same
radius of curvature for their respective arcuate paths of
travel. The positioning of the pivot axes is such that the
two paths are off-set a selected distance from one another.
This permits having the edge of the stair tread of one of
the units 300,400 closely adjacent the riser of the other
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uni t .
As previously mentioned the two units move relative to
one another in opposite directions of travel without
interference and in the embodiment illustrated the support
structures 300A,300B etc and 400A,400B etc are in the form
of webs that have notches for receiving the stair risers of
the other flight unit. Referring to figure 2 the support
400A, mounted on cross beams 405 and 406, has notches A, B
and C to receive respective risers 302,303 and 304 of stair
unit 300. The support 300A has notches D, E and F to receive
respective risers 401,402 and 403 of stair unit 400. While
the supports are shown as webs they could also be in the
form of posts projecting upwardly at an angle from stringers
attached to the cross beams 405,406 or 305,306 as the case
may be. Also in the drawings some of the webs ie 400A, 400C
and 400F of unit 400 and 300A, 300C and 300F of unit 300 are
shown as projecting through the treads and risers associated
therewith but this need not be so. They can terminate at the
under side of the treads and risers as do webs 3008, 300D
and 300E of unit 300 and 4008, 400D and 400F of unit 400.
The rigid stair units 300 and 400 are oscillated back
and forth in their respective arcs in synchronized 180
degree out of phase relation by a drive linkage system 200
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that includes a motor 201 driving a speed reducer 201 via v-
belt 203. The speed reducer 202 is mounted on the support
structure 100 and has an output shaft 204 with a crank arm
205 connected thereto. The crank arm is connected by a pin
206 to one end of a link 207 and the other end of that link
is connected by a pin 208 to a plate 210 that is pivotally
mounted on the support structure 100 by a pivot pin 210A.
The plate 210 has pins 209 and 211 secured thereto and off-
set from one another 180 degrees about the plate mounting
pivot pin 210A. A link 315 is connected at one end to the
pin 211 and at the other end by a pin 3I5A to the rigid
stair unit 300. A link 415 is connected at one end to pin
209 and at the other end by pin 415A to the rigid stair unit
400.
In operation the motor 201 drives the speed reducer out
put shaft 204 and the crank arm 205 causes the plate 210 to
oscillate about the plate mounting pin 210A. With the pins
211 and 209 off-set 180 degrees the respective stair units
300 and 400 move in opposite directions. The units are
synchronized so that as one of the units 300 and 400 is
moving up the incline while the other is moving down at the
same rate and distance in the opposite direction.
Referring to figure 3 there is illustrated a log that
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may be part of a pile of logs in an inlet to the conveyor
that has a deflector plate lI0 securely mounted on the
support structure 100. It will be noted the riser 301 is
concave and this concavity corresponds to the arc through
which the unit 300 moves during reciprocation. In figure 3
the log is resting on the stair tread 301A and as the unit
300 moves upwardly so does the log and at the same time the
unit 400 is moving downwardly as indicated by the arrows. In
figure 5 the stair tread 301A has reached its top position
and the log rolls in to position to be engaged by stair
tread 401A. As unit 400 travels upwardly it takes the log
further along the inclined path as is illustrated in figure
6. The oscillating stair units move logs progressively from
a first position to a second position at a higher elevation.
Since the stair treads will support only one log at a time a
collection of logs at the infeed is unscrambled because of
being moved in sequence one at a time. The unscrambler maybe
used to feed logs in sequence one after another to a
conveyor that is an infeed to a down stream wood processing
apparatus or system.
Since the units 300 and 400 travel in equal but off-set
arcs they can be closely adjacent one another without one
running into interference from the other. The close
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proximity to the risers and treads of the two units prevents
debris from dropping through and thus is carried to the top
and is pushed by the last tread 404A over a plate 125 on the
support structure 100 at the outlet end of the conveyor.
The plate has a convex surface corresponding to the path of
travel during oscillation of the unit 400.
The rigid units are assisted by gravity on their
downward direction of travel and this is transferred to the
ascending unit through the drive linkage system. One or more
air bellows springs or cushions 600 is mounted on the
support structure 100 so as to be struck by some part of the
frame of the rigid unit 300 before reaching the bottom point
of travel. There is also one or more bellows air cushions
650 mounted on the support structure 100 so as to be struck
by some portion of the unit 400 before it reaches its bottom
point of travel. The air cushions not only can cushion the
fall but the energy build up can be used to assist in the
initial acceleration of the stair unit as it begins its
travel upward and thus have a fly wheel effect on the masses
reciprocating in an inclined plane.
A prototype built in accordance with the forgoing is
extremely smooth and quiet in operation handling logs
effortlessly. The rigidity and integrity of the stair units
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remains as such during operation without one engaging the
other despite a close proximity of the two stair units.
The risers and treads on the respective units 300 and
400 are spaced apart to provide alternate steps in the
inclined stairway. This is the referred to interleaving.
The stair riser of one unit overlaps the stair riser of the
other unit as is apparent from the drawings and the forgoing
description in reference to the same. The upper surface of
each unit is effectively provided by a rigid plate like
structure.
