Note: Descriptions are shown in the official language in which they were submitted.
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This invention relates to an apparatus to move a
load between a flrst point and a second polnt. In a pre-
ferred application the invention provides a log bundle lift.
Log bundle lifts to transfer bundles of logs, for
example logs floating on a river, up a bank and into a mill
or into a station from which they may be transported, are
well known. Typically the logs are loaded onto a platform
which is then winched or otherwise drawn up the track to an
unloading station at the top. At the top they may be fed to
a conveyor or to any other means of transporting the logs to
a desired destination.
An example of a prior art machine is described and
claimed in Canadian patent 993,903 issued to Smith et al.
The log bundle conveyor of that patent includes forks that
are used to convey the logs first by being positioned under
~he floating logs and then, as the carriage upon which the
forks are mounted is moved upwardly, lifting the logs
upwardly to a discharge station provided above the water. A
second se~ of forks may be provided to engage the trailing
2~ edge of the log bundle or to squeeze the log bundle between
the two log forks so that the bundles can be unbanded and
the logs handled as individual units.
Examples of other generally similar devices, but
not necessarily used for moving log bundles, are disclosed
in U.S. Patent 652,069 Achee; U.S. Patent 594,577 to Suppes
which describes and claims a means for feeding a blast
furnace; U.S. Patent 2,278,946 to Richard et al; U.S. Patent
1,997,217 to Hite which is concerned with a hoist to handle
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material in a mine; ~I.S. Patent 370,678 to Brown which
describes a skip-car useful in filling a furnace and U.S.
Patent 2,5~8,959 to Campbell which describes an extension
ladder including a hoist that may be moved up and down the
latter.
Particularly when the load is large, as in a log
bundle lift, considerable stress is placed on the structure
by the unloading of the logs. As the log bundle reaches
the top of the track the carriage tips upwardly and the log
bundle sl;des down the remainder of the track with con-
siderable force. As the loads carried are many tons the
structure can suffer considerably and must, in any event,
be of extremely robust construction.
The present invention provides a lift that is
particularly directed to avoiding the damage done to a
structure by the unloading of a heavy load and is of par-
ticular application as a log bundle li~t because it reduces
the damage done by the unloading of the heavy log bundle.
~ccordingly, the present invention is in an
apparatus to move a load between a first point and a second
point and comprising a carriage adapted to run along an
inclined track between the two points and means to recipro-
cate the carriage on the track the improvement comprising
an apex in the track adjacent the second point with a por-
tion of the track being between the apex and the secondpoint and directed downwardl~ towards the second point; the
carriage comprising a main load bearing platform spacedly
attached to a chassis generally horizontal as the carriage
moves along the inclined track, th~ load bearing platform
terminating adjacent the pivotal attachment of the apron;
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an apron pivotally attached to the :Eront of the carriage
and adapted at its leading edge to move along the track
whereby, as the leading edge of the apron mo~es past the
apex .in the track the apro~ pivots downwardly so that the
load bearing platform and the apron form a generally con-
tinuous flat surface, directly downwardly towards the
second point, and down which a load may slide when the
leading edge of the apron passes the apex.
In a further desirable aspect there is an inflec-
tion or change in dir~ction downwardly in the track justprior to the apex.
An embodiment of the invention is illustrated in
the accompanying drawings, in which:
Figure l is a side elevation of a log bundle lift
according to the present invention;
Figure 2 is a further detail of a log bundle lift
of Figure l, at the bottom of a track;
Figure 3 is a section along the line 3-3 in
Figure 2; and
Figure 4 is a perspective view of a further embo-
diment of the invention.
The drawings illustrate an apparatus to move a
load between a first point 2 ~see Figure 2) and a second
point 4 ~see Figure l). There is an inclined track 6 bet-
ween the two points and a carriage 8 is reciprocated on the
track 6. There is an inflection 9 in the track just prior
to an apex 10. The apex 10 is generally adjacent the
second point 4. The track continues at 12 after the apex
10 to the second point 4.
The carriage 8 comprises a main load bearing
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platform 14. There is an apron 16 pivotally attached at 17
to the front of the carriage 14. The apron is adapted
adjacent its leading edge 18 to move along the track 12 by
the provision of a roller 20 which, as shown in Figure 3,
engages a central rail 22.
In addition to the load bearing platform 14 the
carriage 8 has a chassis 24 provided with bogies 26 to
engage side rails 28 of track 6 - see Figure 3. The load
bearing platform 14 is spaced from and attached to the
chassis 24 by the provision of beams 30 and 32. The arrange-
ment is such that as the carriage 8 moves along the inclined
track 6 the load bearing platform 14 is generally hori-
zontal - see Figure 2. There is a restraininq device 3
attached to the trailing edge of the platform 14. This
restrains the logs on the platform 14 and, in particular,
means that the straps used on a log bundle as it i5 floated
downstream can be removed in the water so that the logs may
be lifted as a load of i.ndividual logs rather than as a log
bundle.
The apron 16 is pivotally attached to the front of
the carriage 8 by a hinge 36. The carriage 8 is moved up
the track 6 by a winch 38. A cable 40 leads from the winch
38 around a first sheave 42 located on bracket 44 at the
upper end of the track 6 around a second sheave 46 secured
on a second bracket 48 on the chassis 24 and down to an
adjustable tail hold 5~ on the superstructure used -to mount
the track adjacent the second point 4, that is adjacent the
log unloading position. The superstructure generally
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comprises I-beams 52 and the details will not be described
fully here except to emphasize that generally speaking they
may be of lighter construction than in the prior art.
The illustrated device operates as follows. At
the starting position shown in Figure 2, with the winch 38
at rest, a log bundle is loaded onto load bearing platform
14. The bundle is retained on the pla~form by the restrain-
ing means 34 and, because of the restraining means, if
desired the conventional straps may be removed from the log
bundle in the water. When the load is secured the winch 38
is operated to draw the carriage 8 up the track 6. As the
leading edge of the chassis 24 passes the start of inflec-
tion 9 and the leading edge 18 of the apron 16 passes over
the apex 10, approaching the position shown in Yigure 1, the
apron 16 pivots slowly downwardly around hinge 36 and the
platform 14 tilts to assume the position shown in Figure 1.
The logs move relatively gently down the incline formed by
the load bearing platform 14, the apron 16 and the upper
portion 12 of the track ~.
Tension in the cables 40 is balanced by the tail
hold 50.
In order to facilitate unloading it is desirable
that the platform 14 and the appropriate portions of the
; track be provided wlth low friction inserts, for example
plastic inserts.
It has been found that when the platform is tipped
to an angle of approximately 12 the performance is excel-
lent. The bundle of logs slides smoothly off the carriage
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onto upper portions of the track.
It should be noted that as the carriage 8 moves up
the track 12, that is as it is in the position shown in
Figure 2, the apron 16 is inclined upwardly and the logs
thus abut the apron 16 and not the track. The uniform line,
shown in Figure 1, formed by the carriage the apron and -the
upper portion of the track also ensure smooth unloading of
the device.
The angle of the track is of little importance.
Track angles from 15 to 75 to the horizontal are appro-
priate and, generally, whatever the terrain requires can be
accommoda-ted.
The inflection 9 is not necessary. If platform 14
is inclined so that, referring to Figure 2, it is closer to
being perpendicular to the track the inflection may be
dispensed with. Similarly, the superstructure of I-beams 52
may be replaced by a structure of different beams or by a
concrete structure.
Figure 4 illustrates an embodiment in which a
20 track 106 is formed as a channel and a carriage 108 moves on
wheels within the channel. The carriage 108 is of generally
similar structure to carriage 8 but is simpler. In par-
ticular the replacement of bogies 26 by wheels simplifies
the general structure although the wheels necessitate a
channel track rather than a single rail as is possible with
bo~gies. Generally carriage 108 will have -two wheels on a
common axle at each corner of the carriage 108 and running
in track 106.
~ igure 4 also shows in more detail a suitable
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winch arrangement. The winch has a divided drum 110 driven
by shafts 112 for a motor 114, there is a divided drum 110
on each side of the structure although only one is shown in
Figure 4. Thus there are a total of four cables 116, only
two of whlch are shown. Multiple sheave blocks 118 are
positioned outwardly of the track 106. The sheave blocks
118 on one side of the hoist are reeved with the pair of
cables 116 from the drum 110 coming over the outside sheaves
and continuing back and forth over as many sheaves as is
necessary to provide the required lifting force. The cables
end by coming over the central two sheaves and down to an
adjustable tail hold 120 that will balance the tension in
the cables 116. If necessary the winch can be positioned
well off to one side and, again, the lines may run over as
many turn blocks as necessary.
It will be appreciated to the skilled man that
there is little of invention in the notion of pulling a
carriage up a track by a winch operating through cables and
sheave blocks. It will also be appreciated that there are
wide numbers of other systems that can be used.
Concerning the illustrated structures the apron 16
can be a pair of arms, one over each track, or a full width
platform. It is merely important that the apron facilitate
smooth unloading and also! to a lesser extent, reduces
friction while the load is being raised.
Simllarly the main platform 14 may be a simple
pair of arms or a full width platform or other configura-
tions intermediàte. Again the essential feature of the
invention is the pivoting apron and the actual structure of
these components is the sort of information easily available
to the skilled artisan.
