Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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1475-1
TREE DELIMBING HEAD FOR BOOM-TYPE DELIMBERS
Field of the Invention
The invention relates to tree delimbing devices,
specifically to attachments to the delimbing machines equipped
with booms.
Discussion of the Prior Art
The felling and harvesting of timber is not an easy task,
especially for larger trees. The timber industry is continually
in search of better and faster methods to harvest and process
felled trees. One necessary task in the harvesting of trees is
the removal of rotten or useless pieces of the tree. This
removal of useless pieces of the tree along with the discarding
of parts of the trunk that have either become rotten or that are
too small in diameter to be of use includes removing parts of the
trunk that have a break or a snag. The above task is
necessary given the conditions surrounding the growth and
harvesting of trees. For the timber industry, the most useful,
and therefore most important part, of the tree is the healthy
trunk with a mostly uniform diameter. Thus, other parts of the
tree, such as its branches, are not as important and can be
discarded. Another part of the tree that can be discarded is its
top. Given that trees grow out from the top most part of its
crown, the top end of the trunk, the most recent growth of the
tree, does not have a diameter similar to the rest of the trunk.
As such, this top end of the trunk must be discarded to yield the
useful parts of the trunk. Furthermore, since trees that are
felled are not immediately processed and sent to a timber plant,
felled trees can lie on the ground for significant periods of
time. Unfortunately, this can result in rot setting at the
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bottom of the trunk. Such rotten ends of the trunk are also
useless and must be discarded.
Another problem with rot arises when the felled tree has a
break in the trunk. Such a break, because of being left on the
ground for significant periods of time, can cause rot in both
parts of the broken trunk. The two ends of the trunk would
therefore have to be cleaned up by removing their rotten ends.
This operation involves cutting the trunk close to the position
of the break on the trunk. Often, this position is somewhere
within the middle portion of the trunk where the tree can be at
its thickest.
From the above, it can be seen that the processing of a tree
trunk to remove the useless portions can have three distinct
steps:
1) removal of the tree top or broken end (topping)
2) removal of the rotten end of the trunk (butting)
3) removal of the branches or limbs (delimbing)
This processing is ideally done at the tree harvesting site
and before the tree trunk is sent to the timber plant. Numerous
machines have therefore been invented to try and make the above
process easier.
A patent issued to Jorgensen, Canadian patent 779,081,
discloses a machine for the trimming of felled trees. The
machine has a telescoping boom and a gripping'tool at the end of
the boom. The machine removes the . limbs of a felled tree by
moving the gripping tool down the trunk of the felled tree. The
gripping tool is equipped with a trimming tool that can remove
the less useful tree tops from the trunk. Also disclosed in the
patent is a second device attached farther down the boom. This
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second device is a cutting tool of the saw or shears type capable
of cutting the tree into specific lengths and removing rotten
portions of the trunk.
Unfortunately, the above device suffers from a number of
draw backs. Specifically, it suffers from having to move the
felled tree up the boom to remove both rotten portions of the
trunk and the tree top. To remove the tree top and rotten
portion of the trunk while preserving the trunk's length, the
machine (1) picks up the tree for the first time from the tree
top end, (2) removes the top, (3) removes the limbs, (4) drops
the tree, (5) picks up the tree for a second time from its bottom
end, then (6) removes the rotten end. This necessitates numerous
steps that the machine operator has to follow along the with the
attendant consumption of fuel and time. Also, the patent notes
that if the trunk is gripped from its bottom end, the total
working range of the machine is reduced.
Another device using a sliding boom mechanism is disclosed
in US Patent 5,568,829 issued to Crawford et al. Crawford et al
discloses a delimber machine with a grappling head having
grappling arms and a topping saw. Unfortunately, this topping
saw is only capable of removing the tops of trees. There is no
means disclosed for removing rotten ends of large trunks.
It is clear from the above that an improved delimbing head
is needed that does not suffer from the above drawbacks. What is
required is a delimbing head that simplifies not only the
delimbing operation but also the topping and butting operations
as well. Such a head would combine all three operations into one
device and can preferably be retrofitted onto existing boom-type
delimbing machines.
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~~"mmar~ of the Invention
The present invention overcomes the deficiencies identified
in the prior art by providing a tree delimbing head which
combines a topping knife assembly with a butting saw assembly in
a single unit.
The present invention provides for a delimbing head for a
tree delimbing apparatus having a boom, the head comprising a
body, boom attachment means to attach the body to the boom, a
chainsaw assembly attached to the body, a topping knife assembly
attached to the body, and a gripping arms assembly attached to
the body wherein
1) the gripping arms assembly grips a felled tree trunk such
that a longitudinal axis of the trunk is substantially parallel
to the boom and
2) the chainsaw assembly, the knife assembly, and the
gripping arms assembly are disposed in a single line on the body
of the head.
Preferably, the chainsaw assembly comprises a chainsaw
pivotally attached to the body by a pivot attachment means, means
to operate the chainsaw, and means to controllably swivel the
chainsaw about the pivot attachment means, wherein a controllable
swivel of the chainsaw defines a cutting plane and said cutting
plane is substantially perpendicular to the boom.
More preferably, the gripping arms assembly includes -at
least one pair of cooperating arcuate gripping arms and means to
operate the or each pair of gripping arms between an open
position and a closed position.
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Most preferably, the knife assembly includes a pair of
cooperating blades defining a cutting jaw and means to operate
the cutting jaw between an open jaw position and a closed jaw
position wherein in the closed jaw position a plane defined by
the cooperating blades is substantially perpendicular to the
boom.
Conveniently, each gripping arm has a lip on an inner
circumference, said lip having at least one cutting edge defining
an arcuate plane, said arcuate plane being substantially parallel
to the longitudinal axis of the trunk.
More conveniently, the gripping arms assembly is between the
chainsaw assembly and the knife assembly.
Most conveniently, the chainsaw assembly further includes a
saw assembly delimbing blade attached to a bottom part of the
chainsaw assembly wherein a plane defined by a cutting edge of
the saw assembly delimbing blade is substantially parallel to the
boom.
Also preferably, the knife assembly further includes a
knife assembly delimbing blade attached to a bottom part of the
knife assembly wherein a plane defined by a cutting edge of the
knife assembly delimbing blade is substantially parallel to the
boom.
In another embodiment of the invention, there is provided a
delimbing head for a tree delimbing machine having a boom, the
head including means to slidably attach the head to the boom,
means to control the position of the head on the boom, chainsaw
cutting means pivotally attached to the head, trunk gripping
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means for gripping a tree trunk, said trunk gripping means being
attached to said head, topping knife means attached to said head,
and a plurality of delimbing blades attached to said head, each
delimbing blade having a cutting edge defining a plane parallel
to a longitudinal axis of the trunk.
Yet another embodiment of the invention provides for a
delimbing head for a tree delimbing machine having a telescopic
boom, the head including means to attach the head to the boom, a
chainsaw pivotally attached to the head, a pair of arcuate
pincers for gripping a tree trunk about a circumference of the
trunk, the pincers having an open and a closed position and at
least a pair of cutting edges parallel to a longitudinal axis of
the trunk, a pair of cutting jaws for cutting tree tops, and
delimbing blades attached to said head, each delimbing blade
having a cutting edge defining a plane parallel to a longitudinal
axis of the trunk wherein the chainsaw, the cutting jaws, and the
arcuate pincers are adjacent to one another.
The advantages of the invention are numerous. The need for
a butting saw close to the cab of a delimbing machine is removed,
thus making the machine cheaper. By combining the butting saw
with the topping knives, less movement of the boom is required.
Also, any length of trunk can be cut off from the main tree trunk
using the butting saw. Furthermore, the head can be retrofitted
to existing delimbing machines, obviating the need to buy a
completely new machine to take advantage of the benefits of the
new head.
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Brief Descri8tion of the Drawing:
A better understanding of the invention may be obtained by
reading the detailed description of the invention below, in
conjunction with the following drawings, in which:
Figure 1 is a diagram of a tree delimbing machine.
Figure 2 is a side view of a tree delimbing head in
accordance with the invention.
Figure 3 is a front view of a chainsaw assembly according to
the invention.
Figure 4 is a front view of a knife assembly as used in the
invention.
Figure 5 is a front view of a gripping arms assembly as used
in the invention illustrating an open position.
Figure 6 is a front view of a gripping arms assembly as used
in the invention illustrating a closed position.
Detailed Description of the Preferred Embodiment
Referring to Figure 1, a boom-type tree delimbing machine 10
is shown. The machine 10 has a boom 20 which can be
telescopically or slidably extended. At the end of the boom 20
is the delimbing head 30.
Referring to Figure 2, the details of the head 30 are
disclosed. The side view of the head 30 shows its three main
components: the chainsaw assembly 40, the grappling arms assembly
50, and the topping knives assembly 60. As can be seen, the boom
20 is above the three assemblies 40, 50, and 60. Figure 2 also
shows the end delimbing blades 70 and 80. The delimbing blade 70
is attached to the door 90 of the chainsaw assembly 40 while the
delimbing blade 80 is attached to the face plate 100 of the knife
assembly 60.
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Figure 3 shows the inside of the chainsaw assembly 40. The
chainsaw 110 is attached to the assembly by means of a pivot 120.
The pivot 120 can swivel the chainsaw 110 by either hydraulic or
electrical means. At its rest position, the chainsaw 110 is
housed within the chainsaw assembly housing 120. The chainsaw
110 is well known and its operations will not be discussed here.
However, it must be noted that the chainsaw 110 is activated and
operated from within the cab 130 of the delimbing machine 10.
The pivot 120, which controls the swivelling action of the
chainsaw 110 is also operated from within the cab 130 by a
combination of hydraulic and electrical means. Upon activation,
the chainsaw 110 is turned on and, when desired, the pivot 120
swivels the chainsaw 110 downwards. This has the effect of
cutting the tree trunk that is held parallel to the boom 20.
After cutting the trunk, the chainsaw 110 is then retracted into
its housing 120. The chainsaw 110 is therefore only activated
and operated when desired.
It should be noted that in previous designs, as in the
Telescopic Boom Delimber DT-3000 produced and sold by Denharco
Inc., a chainsaw attached to the head, without a corresponding
knife assembly as disclosed here, is always active. In the
Denharco design, because the chainsaw is the only cutting tool on
the delimber head, the chainsaw is always running. This
therefore leads to a waste of expensive chainsaw fuel and
increased wear on expensive chainsaw parts.
Figure 4 details the topping knife assembly 60. As can be
seen, the knife assembly 60 has a pair of cooperating blades 150,
160. These blades 150, 160, in the closed position (as shown in
Figure 4 ) meet at a point 170 . In the open position the tree
trunk would be between the blades 150, 160. When desired, the
blades 150, 160, operated by a suitable combination of electrical
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and hydraulic means (not shown), close and cut off the
undesirable top part of the trunk. The topping function of the
head is thus accomplished. Again, it must be noted that the
operation of the knife assembly 60 is accomplished from within
the cab 130. Well known control mechanisms are to be used in
controlling the knife assembly 60.
Figure 5 shows the workings of the gripping arms assembly
50. The arms assembly 50 comprises a pair of arms 170, 180 and
suitable mechanisms to operate the arms 170, 180 between an open
position (shown in Figure 5) and a closed position (shown in
Figure 6). In the closed position, the arms 170, 180 grip the
tree trunk while in the open positions the arms 170, 180 release
the trunk. From Figures 5 and 6, we can see a lip 190. Each arm
170, 180 has a lip 190 which protrudes and has a cutting edge on
at least one side. The relevance of the lip 190 will be
explained below. It should be noted that the control of the arm
assembly 50 is accomplished from within the cab 130. Again,
suitable and well known control mechanisms are used.
An example of the delimbing, topping, and butting of a trunk
best illustrates the workings of the head 30. To begin, the arms
170, 180 are locked in the open position. The boom 20 is then
tilted to enable the arms 170, 180 to grip a felled tree close to
either its top end or its bottom end. If gripping close to the
bottom end, the head 30 activates its chainsaw 110 to remove the
rotten bottom part of the trunk. The boom 20 then retracts and
holds the trunk by a second gripping arms assembly 200. This
secures the trunk 140 so that the delimbing operation can
proceed.
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The delimbing proceeds by extending the boom 20, while
holding the trunk captive by the second arms assembly 200. This
has the effect of running the head 30 along the length of the
trunk 140. By holding the arms 170, 180 in the closed position,
the lip 190 on each arm 170, 180 removes the branches that are in
its path. Also, the delimbing blade 70 accomplishes the same
object with respect to the branches not reachable by the arms
170, 180.
To further remove branches left behind, the boom 20 can be
retracted, while again holding the trunk stationary. Delimbing
blade 80 and the opposite side of lips 190 on arms 170, 180 then
further remove any stumps or branches left behind by the initial
pass of the head 30.
For the topping operation, the head 30 is moved to the top
end of the trunk. The cooperating blades 150, 160 heretofore in
the open position, are then engaged, cutting off the tree top.
The blades 150, 160 thus removes the undesirable tree top.
If, on the other hand, the trunk is gripped close to its top
end, the procedure outlined above is reversed. First, the
topping operation is performed by clipping the tree top using the
cooperating blades 150, 160. This may cause the arms 170, 180 to
lose its grip of the trunk as it now grips the clipped tree top.
Machine 10 can then re-grip the clipped trunk and proceed
normally with the delimbing and butting operation. -
Should the tree have a break in.the middle of the trunk, the
procedure to be followed is similar to that for the topping
operation. The head 30 is moved to a position close to the break
on the trunk. Then, should the use of the cooperating blades 150,
160 be inappropriate, perhaps because the trunk at this point be
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too thick to be sheared by the blades 150, 160, the chainsaw 110
is used. The chainsaw 110 is activated and used to cut the trunk
at a point close to the break. Now that the trunk is in two
sections, the machine 10 then picks up the second section of the
trunk and removes its rotten portion. The normal delimbing and
butting process as outlined above can then proceed on the
separate sections of the trunk.
It must be noted that the arms 170, 180 can have a single
common pivot or be separately pivoted. This pivoting option also
applies to the cooperating blades 150, 160.
Furthermore, while the diagrams in this document show the
arms assembly 50 as being between the chainsaw and the knife
assemblies, this is not the only possibility. It is preferred
that the arms assembly 50 be between the chainsaw and knife
assemblies with the chainsaw assembly 40 nearest to the cab 130.
However, any one of the assemblies can be between the other two.
These alternatives would necessitate a relocation of the
delimbing blades 70,80 to the outside assemblies.
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