Note: Descriptions are shown in the official language in which they were submitted.
1~37390
This invention relates to a method and apparatus for
splitting logs and an improved method in logging operations
in general.
Conventionally, logs are split by driving a wedge, i.e.
an axe, into one end of the log either manually or by machine.
l'he process is slow for several reasons, one being that the
axe must be moved back and forth (or the log moved relative to
the a~e) and ano.her being that each log to be split must be
handled individually and appropriately positioned for the
splitting operation. Because of the back and forth or reciprocal
~ovemellt involved, the process may be considered as an inter-
rupted or intermitten~ process. Also, as only one log is
handled at a time it may be referred to as a single stick
process. The drawbacks of a single stick, interrupted process
are obvious and results in low productivity and thus relatively
high cost.
The conventional wood splitting process is not only
slow and costly b-~t also perhaps a determining factor in the
systeMs and procedures employed in a logging operation. In a
conventional process, trees are felled and normally delimbed
at or near the felling site. The delimbed logs are then trans-
ported to a central bucking site (and perhaps a still further
bucking site) and then split at that site or some further site
remote therefrom.
~ne obiect of ~he present invention is to provide a
r:lethod and apparatus for splitting logs whereby the splitting
May be feasibly and economically carriec~ out either at or near the
tree felling or delim~ing site, or a site remote therefrom. Split-
ting also may be done either before or after the delimbinq process.
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In conventional logging procedures logs or whole trees are
piled one on top of another and side-by-side on a vehicle for
transport to another site and this results in a voluminous load
because of voids or open space in the load. The open space
occurs because the logs are round and in many instances croo~ed.
Theloads of logs are transported over roadways and since the
width of a load is limited by law, one can increase the size
of load for a given vehicle only by increasing the height
and that obviously is undesirable.
An object of the present invention is to provide an
improved method of loggin~ whereby more compact loads are
obtained for transport purposes from the felling site to another
site remote therefrom by reducing the voids or open spaces
in a load.
In conventional logging where whole logs are transported
from, for example, a felling site to another site remote
therefrom, a portion of the weight results from moisture con-
tained in the logs.
An object of the present invention is to provide a metl~od
of logging whereby a portion of the moisture content is
removed from the logs after they have been felled and delimbed
and before they are transported to other locations.
A prirnary object of the present invention is to provide
a method and apparat~s for splitting logs which herein is
termed a continuous process and what is meant there~y will
become more obvious and more fully defined hereinafter.
Another object of the present invention ls to provide
a method and apparatus whereby a number of logs can be split
1~37390
simultaneously, thereby increasing productivity.
Another object of the present invention is to provide
a method and apparatus of splitting logs whereby split logs of
considerable length can feasibly and economically be delivered
to a user and later cut by the user into firewood length when
required.
In keeping with the foregoing there is provided in
accordance with one aspect of the present invention a method
of splitting logs comprising moving a log to be split endwise
without interruption in the movement thereof along a selected
path, initiating a crack in the log adjacent the leading end
thereof by forcing wedge means radially inwardly a selected
depth into the periphery of the log and in a direction of the
length thereof as the log moves along said path and causing
said initiated crack to progress longitudinally along the
log toward the other end thereof as it moves along said selected
path until the crack has reached the trailing end of the log.
In accordance with another aspect of the present invention
there is provided an apparatus for splitting logs comprising
a frall~e, a pair of spaced apart parallel rolls journalled for
rotation on said frame for rotation about the longitudinal
axis of the respective rolls, and wedge means on at least one
of said rolls, said wedge means having a longitudinal, narrow,
outer edge extending in a direction around the periphery of
the roll.
The invention is illustrated by way of example in the
accompanying drawings wherein:
Figure 1 is an oblique view of an apparatus provided
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in accordance with the present invention for splitting logs;
Figure 2 is a diagrammatic illustration of a combination
of components including the log splitting apparatus of
Figure 1 which components may be used in various combinations
and sub-combinations for processing logs;
Figures 3A, 3B and 3C are similar end elevational views,
of the type of apparatus shown in Figure 1, illustrating
various modifications;
Figure 4 is a partial, end elevational view, similar
to Figure 3, illustrating a log being split between a pair
of splitting rolls;
Figure 5 is similar to Figure 4 illustrating splitting
previously split pieces of the log;
Figures 6 and 7 are right-hand side elevational views of
respective Figures 4 and 5;
Figures 8A and 8B are two similar views illustrating
minor variations in the relative positioning of the wedge
splitting formations on the splitting rolls;
Figure 9 is a diagrammatic elevational view of a system
for splitting firewood utilizing the device of Figure 1 but
oriented differently;
Figure 10 is an oblique diagrammatic view illustrating
splitting a plurality of logs simultaneously; and
Figure 11 is a side elevational view illustrating a
modified arrange~ent in the mounting of the splitting rolls.
Referring in detail to the drawings illustrated in
Figure 1 is a log splitter 100 consisting of an upper log
splitting roll 101 and a lower log splitting roll 102 each
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journalled for rotation about a horizontal axis. Each log
splitting roll can be driven or only one as illustrated in
Figure 1 wherein the lower is driven by a hydraulic motor 103
througll a speed reduction unit and chain 105. A hydraulic pump
104 supplies fluid pressure for apparatus and is driven by any
suitable power source, for example an internal combustion
engine as represented by tl~e block in broken line designed 106.
The motor, pump and rolls are mounted on a frame consisting
of a weldment of rigid members providing a base 107 and an
upstanding portion 108. The upstanding portion consists of
spaced apart I-beam posts 109 and 110 interconnected by a cross
member 111. The upper log splitting roll 101 is journalled for
rotation in bearings mounted on pillow blocks 112 and 113
vertically slidable on the flanges of respective upright I-beams
109 and 110. Upward and downward movement of the upper log
splitting roll 101 is controlled by respective ones of a pair
of hydraulic cylinder units 114 and 115 provided with fluid
under pressure by the hydraulic pump 103 through suitable
valve means (not shown) manually and/or automatically controlled.
The hydraulic cylinder units may also be suitably controlled
by valving and/or accumulators to resiliently urge the upper
roll downwardly toward the lower roll whereby the upper roll
can move up and down but is always resiliently urged downwardly
a selected amount and toward a selected minimum spacing between
the upper and lower roll.
In Figure 1 each of the upper and lower log splitting
rolls 101 and 102 have a plurality of axe-head like log
splitting formations mounted thereon spaced apart from one
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another both circumferentially around the roll and longitud-
inally therealong. Each axe-head like splitting formation is
identified by the reference numeral 120 and has an outer
sharpened edge 121 extending arcuately around a portion of
the periphery of the roll. The cutting edge 121 of one axe-head
like formation is aligned circumferentially with the next
adjacent formation 120 around the roll and spaced a selected
amount therefrom and the next adjacent one longitudinally along
the roll. A log to be split is fed manually and/or by power
driven feed rolls or other suitable conveying mechanism between
the two log splitting rolls 101 and 102. The log is propelled
end-wise by the power driven lower roll 102 and with the spacing
between the upper and lower roll less than the diameter of the
log, the formations are forced radially inwardly into the logs
from the outer periphery thereof and in the direction of the lengh
of the log as it moves endwise longitudinally between the
rolls. As the first sharpened edge 121 of one formation
contacts the log it initiates a crack in the log and the crack
is continued by the next following formation having the
sharpened edge 121 in alignment therewith. As the log passes
end-wise between the rolls; parallel cracks can occur in
large diameter logs if desired by suitable selection in the
spacing of the axe-like formations axially along the rolls.
The logs are split as they move without interruption
in the movement and thus the process herein is thus referred to
as a continuous process.
A complete log splitting system is illustrated in
Figure 2 and referring to the same t~lere is illustrated a
1~3'7390
iog splitter 100 of the type illustrated in Figure 1 with
a log 200 being propelled end-wise therethrough in the
direction of arrow A and split by the splitter into a plurality
of pieces 201. The log 200 is fed to the log splitter by
conveyor and guide means consisting of rolls 301, 302 and 303.
At least one roll is driven and conveniently so by a hydraulic
motor located at the end of the roll or interiorly thereof.
The rolls may be a simple cylinder as, for example, roll 303
or have one or more sections of reduced area, i.e. V-shaped
notches in the surface for guiding a log along a selected path
between the splitting rolls. Roll 302 can be mounted on a
rigid frame (not shown in Figure 2) while roll 301 may be
mounted by arms and hydraulic cylinders for movement toward
and away from the lower roll 302 (see Figure 1). Roll 303
is a hold down roll mounted by arms 304 on a rigid frame 305
and controlled by hydraulic cylinder units 306.
The log may be cut cross-wise into selected lengths by
severing device 400 upstream of the splitter and additionally
or alternatively, a second severing device 500 located
downstream of the splitter 100. The split logs 201 can be dis-
charged onto a conveyor 600 that moves the split logs to a
bundling or collecting station 700 or alternatively, directly
into a collecting and/or bundling means.
~he log severing device 400 consists of a circular
saw 401 driven by a hydraulic motor 402 and mounted on an
arm 403 suspended from a reciprocably movable carriage 404.
The carriage 404 is mounted for reciprocal movement in a
channel 405, movement of the carriage being effected by a link
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chain 406 passing around idler sprockets mounted respectively
on the channel 405 and the carriage 404. The link chain passes
over a sprocket 407,driven hydraulic motor 40~ and idler
sprockets 409 mounted on the channel. The arm 403 is pivotally
mounted as at 410 and the saw is raised and lowered by
hydraulic cylinder unit 411. The reciprocally movable
carriage 404 allows severing the log with the power driven
saw during movement of the log thereby avoiding interruption
of the movement of the log during splitting. Suitable sensors,
speed control means and/or valves may be provided to initiate
the severing device and coordinate the rate of movement
of the carriage and the log.
The severing device 400 can be located upstream of the
splitter as shown in Figure 2, or alternatively downstream
therefrom. Also, the severing device 400 in place of being
a power driven circular saw may be a hydraulically operated
shear mechanism as, for example unit 500 illustrated havingasingle
blade (or if desired two or more blades). The severing devices
400 and 500 are what may be termed a flying severing device,
as they move with the work piece during severing and as such
devices are known in the art no further description of the same
is believed necessary other than to perhaps point out severing
device 500 can be mounted for reciprocal movement in the
same manner as severing unit 400.
In Figure 1 the upper splitting roll 101 is movable
toward and away from the lower splitting roll 102 by hydraulic
cylinder units 114 and 115. Figures 3A, 3B and 3C illustrate
alternative means for moving the upper splitting roll to adjust
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the space between the splitting rolls and urging the
top roll downwardly toward the bottom roll. Figure 3A is
similar to the embodiment illustrated in Figure 1 but it will
be noted the hydraulic cylinders are located above the roll.
Referring to Figure 3A, lower splitting roll 102 is jourslalled
for rotation on a base 107 by a pair of bearings 120 and
driven by hydraulic motor 103. Projecting upwardly from the
base are a pair of uprights 109 and 110 on which are slidably
mounted a pair of journals 131. The upper splitting roll 101
is journalled for rotation in journals 131, the latter being
movable by a pair of hydraulic cylinders 132. In Figure 3B
the upper splitting roll 101 is vertically movable by a pair of
screws 140 journalled for rotation in the upper cross-bar 111
and illustrated in respectively the left and right-hand side
of the drawing are two different drives for the screws. On the
left-hand side the screw 140 is driven by an electric or
hydraulic motor unit 150 through an angle and gear reduction
drive 151. In such an arrangement, obviously the other screw
would be driven in a similar manner and in timed relation to
raise and lower the upper splitting roll. One motor 150 could
be utilized to drive both screws 140 through any suitable drive
means such as, for example chain and sprockets. On the right-
hand portion of the drawing is illustrated a crank unit 160
that s.lay be manually turned. Numerous variations are possible
~or turning the screws and turning the same in tlmed relation
with respect to one another. In Figure 3C the upper splitting
g _
1~3739(~
roll 101 is suspended from a pair of compression springs 170.
The upper end of the compression springs can be secured to the
frame or alternatively to blocks adjustably movable vertically
on the frame.
Figures 4 and 5 illustrate splitting a log into
portions 201 by the wedge formations on respectively the upper
and lower splitting rolls 101 and 102. The wedge formations
penetrate the log from both the top and bottom inwardly
towards the center of the log. It will ~e observed in Figure 4
the splitting wedges on the upper roll 101 are in alignment
with the splitting wedges on the lower roll 102. In Figure 5
there is illustrated splitting a previously split log into
smaller pieces. This can be done by a second pass between
the rolls or also in instances where the log splits full length
while still between the rolls andthese split pieces roll over.
In the latter instance, should one wish to avoid the additional
splitting suitable controls can be placed in the hydraulic
syster.l and/or control for movement of the upper roll limiting
its amount of movement once the log has entered between the
rolls and splitting commenced. The depth of penetration of the
wedge formations can in any convenient manner be controlled to
cause splitting but limited such that splitting will not occur
in the smaller 5pl it pieces of the log.
As clearly seen in Figures 4 to 7 inclusive, the
sp~itting wedge formations 120 are spaced apart from one another
circumferentially around each splitting roll and also axially
along each roll. Alignment of the wedges on the upper and
lower rolls axially along the rolls is illustrated in Figure ~A
-- 10 --
1137390
and in Figure 8B the wedges are off-set from one another.
In actual tests, wedge formations having a 60 included angle
with axe points 2 cm long were found to work quite satis-
factorily. In the test device, eight such rows of wedge
formations extended axially along a roll 60 cm long and having
a diameter of 22.86 cm. In the test machine the gap between
the rolls could be adjusted from .5 cm to 12 cm between the
axe points and the lower roll.
Referring to Figure 9 there is illustrated an arrangement
for splitting, for example firewood, wherein a splitter, of
the type illustrated in Figure 1, is arranged such that the
splitting rolls 101 and 102 are spaced apart from one another
horizontally and the logs to be split dropped therebetween.
Logs 200 to be split are conveyed one after another along
conveyor 700 and as they pass over the end of the conveyor they
drop endwise vertically downwardly between the splitting rolls.
Suitable guide mechanisms may be employed which are not shown
to ensure the log in its free fall is appropriately aligned
between the splitting rolls and oriented endwise as illustrated.
Splitting roll 102 is power driven and preferably roll 101 is
also driven. The splitting rolls 101 and 102alsopreferably
are driven to rotate such that the peripheral speed of the outer
ends of the splitting formations is greater than the rate of
fall of the log as it enters between the nip of the rolls.
The split logs as they emerge from the splitting rolls can be
dropped onto a conveyor,not shown, (or collecting ~ucket~ for
removal to another site.
Referring to Figure 10, there is illustrated a log
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splitting device 100 as described with reference to FiguLe 1
simultaneously splitting a plurality of logs 200. The logs
as they emerge from the splitter are conveyed to a bundling
or collecting station by a belt or any other suitable conveyor
800. Of particular note in the Figure 10 embodiment is the
upper guide roll 301 which has a plurality of side-by-side
generally V-shaped grooves 305 located side-by-side axially
along the roll for guiding the plurality of logs and separating
one from another.
Another arrangement for mounting the upper and lower
rolls is illustrated in Figure 11. In referring to the same
there is illustrated a frame having a rigid base 900 on which
there is mounted a lower roll 901. At one end of the base 900
there is an upstanding rigid frame portion 902 having a pair
of arms 903 pivotally mounted thereon as at 904. A splitting
roll 101 is journalled for rotation on the pair of arms 903
and driven by suitable power means, not shown. The arms 903
are raised and lowered by one or more hydraulic cylinder units
905 appropriately connected to the arms and the base. The
lower roll 901 may be freely rotatable and is devoid of splitting
formations, i.e. a smooth roll.
From the foregoing it will be seen there are various
alternative arran3ements for moving the upper roll relative
to the lower roll as we~l as various arrangements for the
orientation of the splitting rolls and different pieces of
equipment that may be used in various com~inations and sub-
combinations. Also, numerous variations may be made in the
arrangement and positioning of the splitting wedges. Initial
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37390
tests showed that with certain species there was substantial
dewatering during splitting. The removal of moisture was found
to be such that liquid oozed from the log in sufficient
quantity it could be collected. The amount of liquid removed,
i.e. dewatering, is dependentupon the species and moisture
content; for example, with red oak @ 80% moiture content dry
weight basis, it was found little or no liquid was removed while
in other species substantial liquid was removed at a lower
moisture content. By splitting the logs after the trees are
delimbed and before transporting the logs tG another site there
is the advantage of reducing the weight of the load to be
transported or alternatively, it enables hauling a greater
quantity of wood. Removal of moisture also reduces drying time
wnen used as firewood. The roll splitting is a fast, contin-
uous process with the added advantage of partial drying by
removing some liquid during splitting.
Splitting at or near the tree felling site combined
with bundling the split logs results in a more compact load
for transport purposes.
