Note: Descriptions are shown in the official language in which they were submitted.
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TREE FELLING AND SHAPING APPARATUS
THE FIELD OF THE INVENTION
This invention relates to an improved tree felling
and shaping apparatus. The invention more particularly
relates to an improved tree felling and shaping apparatus
of the type that can be rotated about a vertical axis
regardless of the process in which the apparatus operates
for tree felling or tree shaping.
BACKGROUND OF THE INVENTION
Tree felling machines can be broken into two
categories, feller/bunchers and feller/processors.
Feller/bunchers are use for felling and piling trees. A
feller/buncher has a boom with a head mounted at the end of
the boom. The head has arms or other means of gripping a
tree and a saw for cutting the tree at the base. After the
tree has been cut, the cut tree can be processed by another
machine before being shipped to its ultimate destination.
An example of feller/bunchers is described in United States
Patent 5,291,926, entitled CUTTING AND SAWING UNIT PROVIDED
WITH A TIMBER HANDLING ARRANGEMENT, issued to Jansson on
March 8, 1994.
Feller/processors, or tree felling and shaping
machines are machines which can both cut trees and process
the cut trees. Generally, a tree felling and shaping
machine has a tree processor head which includes a central
post, a cutting device at the bottom of the central post,
and gripper and stripping means attached to the central
post. The tree felling and shaping machine generally has a
boom mounted to a vehicle and the tree processor head is
typically mounted to the boom with a joint link system
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which has at least two degrees of freedom. The head can be
tilted toward, or away from the machine about a first axis
transverse to the boom. The head may also be tilted side
to side about a second transverse axis, which is generally
longitudinal to the boom when the head is upright, or may
be pivoted about a second transverse axis which is at an
angle from the first axis. These two degrees of freedom
allow the head to be aligned with a tree that is not
perfectly vertical. After the tree has been cut the head
can be tilted about the first axis to move relative to the
bottom of the machine to lay trees down transversely to the
bottom for processing. During the processing period the
tree processor head is in a generally horizontal position
and must be freely suspended on the boom or "float" about
the horizontal axis perpendicular to the tree while the
tree is being shaped.
Examples of such tree felling and shaping machines
are described as prior art (referring to Figs. 2A and 2B)
in United States Patent 5,727,610, entitled COMBINED TREE
FELLER AND PROCESSOR, issued to Isley on March 17, 1998.
The prior art feller/processor uses a universal joint to
suspend the processor head from a boom in order to allow
the processor head to pivot freely about a longitudinal
axis and a transverse axis. However, as pointed out by
Isley, mounting a processor head to a boom in a manner
which provides the necessary "floating" action during
processing generally precludes the use of a high speed
continuously rotating saw for tree cutting because such a
mounting would be incapable of controlling the saw under
the action of the large gyroscopic forces. Furthermore,
the un-powered universal joint is not controllable, thereby
reducing the maneuverability of the feller/processor which
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is especially required when the feller/processor is used to
pile and handle the processed trees.
Another example of tree feller/processors is
described in United States Patent 4,800,936, entitled
MACHINE FOR FELLING AND SHAPING TREES, issued to Pomies et
al. on January 31, 1989. Pomies et al. describe a link
system having an un-powered pivoting joint which provides
an additional degree of angular freedom while the tree
processor head is in a recumbent position for shaping
trees, but is disabled while the tree processor head is in
an upright position for felling trees. The un-powered
pivoting joint reduces the maneuverability of the processor
head in the recumbent position. Furthermore, this link
system can not provide any angular adjustment of the
processor head in the upright position for a selected angle
to approach a target tree.
Efforts have been made to improve tree felling and
shaping machines, particularly to improve the joint link
system which operatively links the tree processor head and
the boom in order to make the machine more maneuverable,
thereby increasing the work efficiency of the tree felling
and shaping machine, and reducing operation costs. One
example of such efforts can also be found in United States
Patent 5,727,610 which suggests a fully powered and
controllable link system. This link system however,
compromises a wide selection of approaching angles of the
processor head to a target tree to be cut because of
limited rotational adjustment about a vertical axis when
the head is in the upright position for a tree felling
process so that more boom and vehicle movement is needed to
compensate for this limitation.
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Another example of such efforts can be found in
United States patent 5,709,254 entitled TREE HARVESTING
APPARATUS, issued to Argue on January 20, 1998. A fully
powered and controllable link system described by Argue
includes a helical spline for permitting rotational
movement of a harvesting head about a central vertical axis
thereof. This provides enhanced maneuverability of the
head to prevent damage to saplings or other immature
timber. However, the helical spline provides limited
rotational movement of the head only through a 220° arc.
Therefore, an all direction approach of the head to a
target tree to be cut, cannot be achieved.
The industry continues to search for better tree
felling and cutting machine designs, particularly for one
which provides the capability of angular adjustment of the
tree processor head in all directions of approach to a
target tree during a tree felling process, and in all
orientations during the tree shaping process.
SUN~IARY OF THE INVENTION
It is one object of the present invention to
provide an improved tree felling and shaping system.
It is another object of the present invention to
provide a tree felling and shaping apparatus which is
convenient to manipulate.
It is a further object of the present invention to
provide a link system of a tree felling and shaping
apparatus which is adapted for maximum angular adjustment
about a vertical axis, thereby permitting a processor head
of the apparatus to approach a target tree from any
direction for cutting and de-limbing the target tree.
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The present invention is directed to a fully
powered and controllable link system for operatively
linking a boom and a tree processor. The tree processor
includes a central elongate support member and generally
has an upright position in which the central elongate
support member is substantially vertical for felling a
tree, and a recumbent position in which the central
elongate support member is substantially horizontal for
shaping the tree. The link system includes first, second
and third axes. The first axis is generally horizontal and
a first member is adapted to be pivotally mounted to a free
end of the boom for pivoting about the first axis. A first
axis power actuator is attached to the first member and
adapted to be connected to the boom for tilting the first
member about the first axis. The second axis is
perpendicular to the first axis, and a generally elongate
second member is mounted at a first end thereof to the
first member directly by a rotary coupling, thereby
permitting the second member to rotate more than 300°, but
restraining other movement thereof, relative to the first
member about the second axis regardless of the upright or
recumbent processor head position. A second axis power
actuator is attached to the rotary coupling for actuating
the rotary movement. The third axis is perpendicular to
the second axis and is adapted to extend side to side with
respect to the processor head and to be perpendicular to
the central elongate support member of the processor head.
The second member at a second end thereof is adapted to be
pivotally mounted to the central elongate support member of
the processor head for pivoting about the third axis. A
third axis power actuator is attached to the second member
and is adapted to be connected to the central elongate
support member for pivoting the central elongate support
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member about the third axis between the upright and
recumbent positions.
The present invention is also directed to a tree
felling and shaping apparatus of a type having a tree
processor head which includes a central elongate support
member, a cutting device at a bottom of the central
elongate support member, and gripper and stripping means
attached to the central elongate support member. The
processor head generally has a first position in which the
central elongate support member is substantially vertical
for felling a tree, and a recumbent position in which the
central elongate support member is substantially horizontal
for shaping the tree. The apparatus further includes a
boom having an end mounted to a vehicle and a free end, a
first generally horizontal axis and a first member
pivotally mounted to the free end of the boom for pivoting
about the first generally horizontal axis. A first axis
power actuator is positioned to link the boom and the first
member for tilting the first member about the first axis.
The apparatus has a second axis perpendicular to the first
axis and includes a generally elongate second member
mounted at a first end thereof to the first member by a
rotary coupling, permitting the second member to rotate
more than 300°, preferably 360°, but restraining other
movement thereof, relative to the first member about the
second axis, regardless of the first or second processor
head position. A second axis power actuator is attached to
a rotary coupling for actuating the rotary movement. A
third axis of the apparatus is perpendicular to both the
second axis and the central elongate support member of the
processor head, and the central elongate support member is
pivotally mounted to a second end of the second member for
pivoting about the third axis. A third axis power actuator
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is positioned to link the second member and the central
elongate support member for pivoting the central elongate
support member about the third axis between the
substantially vertical and horizontal positions.
With such a fully powered and controllabe link
system, the processor head is conveniently manipulated
between its upright and recumbent positions for either tree
felling or shaping processes by actuating the third axis
power actuator to thereby pivot the central elongate
support member of the processor head while the second axis
of the apparatus is substantially maintained in a vertical
position. Thus, actuating the second axis power actuation
will rotate the processor header about the second axis
which is in a substantially vertical position, regardless
of the processor head position. This configuration
provides a maximum angular adjustment to the processor head
for approach to a target tree to be cut, from any direction
when the processor head is in its upright position, and
permits shaping and de-limbing of the cut tree in any
direction when the processor head is in its substantially
horizontal position.
The generally elongate second member of the tree
felling and shaping apparatus according to the present
invention comprises a configuration permitting the
processor head to be located below the rotary coupling when
the central elongate support member thereof is in the
substantially vertical position. The pivoting and the
rotary links of the tree felling and shaping apparatus are
preferably arranged in a manner such that under the force
of gravity alone the first member with all parts supported
thereby, is adapted to be freely suspended from the boom
when the processor head without a load is maintained in a
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first position. This feature advantageously allows
convenient manipulation of the apparatus when the processor
head is to be aligned with a target tree to be cut.
The fully powered and controllable link system not
only provides maximum angular adjustment of the tree
processor head for all directional orientations whether the
head is in a recumbent or an upright position by also
advantageously performs a universal joint function to
freely suspend the tree processor head from the boom
without using a conventional uncontrollable universal
. joint. This feature will be better understood with
reference to a preferred embodiment of the present
invention described hereinafter.
Other advantages and features of the present
invention will also be better understood with reference to
a preferred embodiment of the present invention described
hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGS
Having thus generally described the nature of the
present invention, reference will now be made by way of
illustration only to the accompanying drawings, showing the
preferred embodiments thereof, in which:
Fig. 1. is a front elevational view of a tree
felling and shaping apparatus according to one embodiment
of the present invention;
Fig. 2 is a rear elevational view of the embodiment
of Fig. 1;
Fig. 3 is a side elevational view of the embodiment
of Fig. 1, showing the tree processor head of the tree
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felling and shaping apparatus in an upright position for a
tree felling process;
Fig. 4 is a side elevational view of the embodiment
of Fig. 1, showing the tree processor head of the tree
felling and shaping apparatus in a recumbent position for a
tree shaping process;
Fig. 5 is a side elevational view of the embodiment
of Fig. l, showing a different pivoting angle of the
processor head in its recumbent position for the tree
shaping process;
Fig. 6 is an enlarged section of Fig. 2, partially
in a cross-sectional view, showing the details of the
hydraulic motor powered rotary coupling of the embodiment
of Fig. 1; and
Fig. 7 is an exploded view of a mobile gear
connected to the hydraulic motor.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings, particularly to Figs. 1
through 4, a tree felling and shaping apparatus generally
indicated at numeral 10 includes a tree processor head 12.
The tree processor head 12 includes a central beam 14 which
carries two pairs of gripping arms 16 and 18 for gripping a
tree and a cut-off saw 20 attached to the bottom of the
beam 14 for cutting the tree. The beam 14 further supports
processing means such as a set of de-limbing knives (not
shown) for processing the tree, and a tree feeder
comprising a pair of feed rollers 22 for moving the tree
along relative to the de-limbing knives after the tree has
been cut. The de-limbing knives may comprise sharpened
edges on the gripping arms 16 and 18.
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The tree felling and shaping apparatus 10 further
includes a fully powered and controllable link system 24 to
operatively connect the tree processor head 12 to a boom 26
which in turn is operatively mounted to a vehicle (not
shown) .
The link system 24 includes a bracket member 28
which includes parallel brackets 30 extending
perpendicularly from an end plate 32. A pin 34 (as shown
in Figs. 1 and 2) is attached to the bracket member 28 and
extends between the two parallel brackets 30. A free end
of the boom 26 is pivotally connected to the pin 34 so that
the bracket member 28 is pivotable about the axis 36 of the
pin 34, which is generally horizontal. An hydraulic
cylinder 38 is provided between the boom 26 and the bracket
member 28 for tilting the bracket member 28 about the
generally horizontal axis 36.
The link system 24 also includes a generally
elongate arm member 40 which includes a pair of parallel
arms 42 (not shown in Fig. 1) connected together at the top
end thereof by an end plate 44. The end plate 44 of the
arm member 40 is rotatably coupled with the end plate 32 of
the bracket member 28 to form a rotary coupling 46 by which
the arm member 40 is rotatably mounted to the bracket
member 28 in order to allow it to rotate about the axis 48
while restraining other movement of the arm member 40
relative to the bracket member 28. The axis 48 is
substantially perpendicular to the axis 36.
At the other end of the arm member 40, the two
parallel arms 42 are pivotally mounted to the respective
sides of the central beam 14 so that the central beam 14 is
enabled to pivot about an axis 50 (shown in Figs. 3-5)
which is perpendicular to both the axis 48 and the central
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beam 14, and extends side to side with respect to the
processor head 12. A pair of hydraulic cylinders 52 (not
shown in Fig. 1) are pivotally linked between the arm
member 40 and the central beam 14, by means of two pairs of
parallel brackets 54 (not shown in Fig. 1) affixed to a
base part 56 (shown in Fig. 2 only) of the central beam 14.
The hydraulic cylinders 52 are provide to actuate the tree
processor head 12 in pivotal movement about the axis 50.
The rotary coupling 46 further includes a fixed gear 58
co-axially affixed to the end plate 32 of the bracket
member 28 and two hydraulic motors 60 (only shown in
Fig. 2) .
As more clearly shown in Figs. 6 and 7, each of the
hydraulic motors 60 is affixed to the end plate 44 by means
of mounting screws. A pinion 62 is engaged with the
shaft 64 of the hydraulic motor by means of splines 66 so
that the pinion 62 will rotate together with the shaft 64
of the hydraulic motor 60. A bearing 68 and a bearing
spigot 70 are used to secure a slewing guide plate 72 to
the top side of the pinion 62 so that when the hydraulic
motor 60 is actuated to rotate and the pinion 62 thereby
rolls along the periphery of the fixed gear 56, the slewing
guide plate 72 slides on an annular slewing bearing
surface 74 formed on the top side of the fixed gear 58
adjacent to the periphery thereof.
Returning to Figs. 1 to 4, the rolling action of
the pinions 62 around the periphery of the fixed gear 58
provides a continuous rotation of the end plate 44 of the
arm member 40, along with the entire tree processor
head 12, about the axis 48, relative to the end plate 32 of
the bracket member 28. However, the manipulation of the
tree felling and shaping apparatus 10 for an angular
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adjustment of the tree processor head 12 does not require
the tree processor head 12 to be rotated about the axis 48
more than 360°, and the hydraulic hoses (not shown) for
supplying the pressurized hydraulic fluid to the hydraulic
motors 60 and hydraulic cylinders 52 will interfere with
the unrestricted rotation of the tree processor head 12
about the axis 48. Therefore, it is suggested that the
rotation of the tree processor head 12 about the axis 48
relative to the bracket member 28 should not be more
than 360°.
The hydraulic system (not shown) designed for the
respective hydraulic cylinders 38, 52 and the hydraulic
motors 60 are enabled to controllably actuate the hydraulic
cylinders 38, 52 and the hydraulic motors 60 in opposite
directions, and hydraulically lock the hydraulic
cylinders 38, 52 and hydraulic motors 60 in any position.
The hydraulic system is also enabled to withdraw hydraulic
pressure which permits the hydraulic cylinders 38, 52 and
the hydraulic motors 60 to be selectively free for passive
relative movement about the respective axes 35, 48 and 50,
for a "floating" linkage, if it is required during a tree
felling and shaping operation.
More particularly, as shown in Fig. 3, axis 36 and
axis 48 in combination define a common plane which is
represented in the side view of Fig. 3 by the axis 48
extending through the pivoting point which is the axis 36.
Furthermore, the arm member 40 is configured in such a way
as to permit the tree processor head 12 to be positioned
below the rotary coupling 46 when the axis 48 is
substantially vertical and the tree processor head 12 is in
an upright position. The axis 48 preferably extends
through the gravitational center (not shown) of the tree
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processor head 12. More preferably, the axis 50 is located
at the gravitational center of the tree processor head 12
so that the tree processor head 12 is enabled to be freely
suspended from the boom 26 under the force of gravity
alone, without locking any one of the hydraulic
cylinders 38, 52 regardless of whether the tree processor
head 12 is in the upright or recumbent position as
illustrated in Figs. 3 and 4 respectively. Nevertheless,
if the axis 50 is in a proximity of the gravitational
center of the tree processor head 12 but not accurately
located at the gravitational center thereof, the tree
processor head 12 is still enabled to freely suspend from
the boom 26 without locking the hydraulic cylinder 38. The
hydraulic cylinders 52 should however, be hydraulically
locked to maintain a selected position of the tree
processor head 12 relative to the arm member 40.
In operation an operator moves the vehicle and the
attached boom 26 in order to properly position the tree
processor head 12 for an approach to the tree targeted to
be felled, while the tree processor head 12 is maintained
in its upright position and is freely suspended from the
boom 26 as shown in Fig. 3. The rotary coupling 46 is
actuated for an angular adjustment of the tree processor
head 12, of up to 360° in order to allow selection of a
best angle of approach to the target tree. When the rotary
coupling 46 rotates the tree processor head 12 to position
axis 50 at an angle with respect to axis 36 (not parallel
to each other), and if hydraulic cylinders 38 and 52 are
not locked, the combination of the free pivotal movement
about the respective axes 36, 50 provides a universal joint
function. This will permit the tree processor head 12 to
be freely aligned with the target tree when the gripping
arms 16, 18 grip the tree whether or not the tree is
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perfectly vertical. The hydraulic cylinders 38, and
hydraulic motors 60 (not shown in Fig. 3) are hydraulically
locked after the tree is securely gripped by the gripping
arms 16, 18. The cut-saw 20 is then actuated to cut the
tree. The rotary coupling 36 then is actuated again to
select a desired direction within 360° to tilt down the
tree, which is done either by actuating the hydraulic
cylinders 52 to pivot the tree processor head 12 with the
gripped tree to the recumbent position, as shown in Fig. 4,
or by simply dropping the hydraulic pressure in hydraulic
cylinders 52 thereby permitting the tree to freely pivot to
the recumbent position. In the shaping, de-limbing and
piling operation the rollers 22 are actuated to feed the
tree through the tree processor head 12 along its
longitudinal length. The unlocked cylinders 52 permit the
tree processor head 12 to swivel freely about the axis 50
while the tree moves through the tree processor head 12 in
response to changes in the gravitational center of the
combination of the tree and the tree processor head 12. A
swiveled position of the tree processor head 12 is shown in
Fig. 5. At the end of the tree shaping operation, the tree
is cut into selected lengths.
The tree processor head 12 in its recumbent
position as shown in Fig. 4, can also be used for handling
and piling the tree lengths if it is required.
With such a fully powered and controllable link
system, the selective control of hydraulic cylinders 38, 52
and hydraulic motors 60 for actuating, locking the
cylinders and motors, or withdrawing the hydraulic pressure
in the hydraulic cylinders and motors, provides a great
convenience for the manipulation of the tree felling and
shaping apparatus 10. The combination of two pivoting
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joints about the respective axes 36, 48 with a rotary
coupling 46 disposed therebetween in the link system 24 not
only advantageously provides a maximum angular adjustment
of the tree processor head 10 for all directional
orientations but also performs a universal joint function
to freely suspend the tree processor head 12 from the boom
without using an conventional uncontrollable universal
joint which is usually used in prior art tree felling and
shaping apparatuses.
Changes and modifications to the embodiment of the
present invention described above may be made without
departing from the spirit and the scope of the present
invention which are intended to be limited only by the
scope of the appended claims.