Note: Descriptions are shown in the official language in which they were submitted.
The present invention relates to a tree delimbing appar-
atus, and more particularly to a device which is adapted to au'co-
matically delimb a previously harvested tree, while simultaneous-
ly loading the tree for transport.
In the tree harvesting arts a number of different types
of apparatus have been previously proposed which are adapted to
harvest and then delimb a tree prior to transportation to the
facility at which the tree trunk is to be used. Likewise, a
number of different types of apparatus have been proposed which
will delimb trees in conjunction with the h~vestingoperation, or
which will delimb previously harvested trees. Such apparatus are
all relatively large and expensive pieces of equipment, and serve
a relatively limited function. In particular, with such appara-
tus it is generally necessary for a separate piece of equipment
to be utilized in order to place the delimbed tree trunk on a
truck bed or the like for transportation. Moreover, previously
proposed apparatus of this type have limited flexibility in the
area within which they can be used and in the xeach that they can
effect in order to engage and delimb a pre-cut kree trunk.
It is anobject of the present invention to provide a
tree delimbing and loading apparatus which is adapted to pick up
a pre-cut tree, delimb it and load it on a transport vehicle or -
the like.
Another object of the present invention i5 to provide a
delimbing and loading head which is relatively inexpensive in
construction, but reliable in use.
A still further object of the present invention is to
provide a tree delimbing and loading head which is adapted to be
mounted on the extensible boom of a mobile vehicle, so that the
head can be moved to a variety of different positions for engag-
ing the pre~harvested tree and moving it, after or during the de-
limbing operation, to a transport vehicle.
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A still ~urther object of the present invention is to
provide a delimbing head whose position on a support boom can be
selectively varied, in order to facilitate engagement of the
delimbing head with a pre-harvested tree lying on the ground.
A still further object of the present invention is to
provide a delimbing and loading head which automatically alters
its own position on a support boom during certain stages of opera-
tion in order to facilitate tree processing.
A still further object or the present invention is to
provide a delimbing and loading head which is capable of process-
ing two trees simultaneously.
A still further object of the present invention is to
provide a delimbing and loading head which gives the operator
substantial control over the placement of loaded trees.
A still further object of the present invention is to
provide a delimbing and loading head which can be efficiently
usecl in a selective-cutting logging operation.
In accordance with an aspect of the present invention,
a tree delimbing and loader head is provided which is adapted to
be mounted on an articulated and extensible boom supported on a
mobile vehicle. The boom has a free end and can be moved through
a variety of positions with appropriate controls in the mobile
vehicle. The~delimbing and loading head includes a frame which
is swivelably mounted on the free end of the boom for pivotal
movement about at least two perpendicularly related axes. On the
frame a tree supporting and delimbing mechanism is provided which
is adapted to automatically remove limbs from the tree as the
tree trunk is moved past the apparatus. A shearing mechanism may
be provided on the end of the frame opposite the delimbing and ,
supporting arrangementr for selectively cutting off a portion of
the tree top ~rom the trunk at the completion of the delimbing
operation. Between the delimbing arrangement and the location
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of the shearing means, a drive mechanism is provided for moving
the tree trunk past the delimbing apparatus towards the shearing
apparatus while simultaneously supporting the tree in the frame.
By this arrangement the tree is delimbed while being moved to and
loaded on a separate transport vehicle by the boom. When the
tree trunk is in its loaded position the top can be sheared from
the trunk. The tree top remains supported on the frame between
the delimbing apparatus and the drive arrangement. Thus, the
tree top can be moved to another location prior to release from
the delimbing head for proper storage and disposal.
The above and other objects,features and advantages of
this invention will be apparent in the following detailed des-
cription of an illustrative embodiment thereof, which is to be
read in connection with the accompanying drawings, wherein:
Figure :L is an elevational view of a tree delimbing and
loader apparatus constructed in accordance with one embodiment
of the present invention, showing the apparatus holding a tree
for delimbing;
Figure lA is an elevational view, similar to Figure 1,
showing the configuration of the apparatus during the delimbing
operation, while positioning a delimbed tree trunk on a trans-
port vehicle;
Figure 2 is a perspective view from below of a tree de~
limbing and loading head constructed in accordance with the
present invention in its open position prior to engaging the tree;
Figure 3 is a side elevational view of the tree delimb-
ing head shown in Figure 2;
Figure 4 is a partial end view of the tree delimbing
apparatus of Figure 3, taken approximately along line 4-4 of
Figure 3, showing the delimbing mechanism;
Figure 5 is a partial end view taken approximately
along line 5-5 of Figure 3, with parts broken away, showing the
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shearing apparatus;
Figure 6 is a sectional view taken approximately along
line 6-6 of Figure 3 showing the drive apparatus for the delimb-
ing and loading head, and also illustratiny a modified drive
mechanism for moving the tree trunk through the apparatus.
Referring now to the drawing in detail, and initially
to Figure l, the tree delimbing and loading apparatus lO of the
present nvention includes a mobile vehicle 12, of conventional
construction, on which an articulated and extensible boom 14 is
mounted. In the illustrative embodiment of the invention boom
14 includes a first leg 16 pivotally mounted on a turntable 18
that is adapted to rotate through substantially 360 under the
control of an operator in the cab 20, in the conventional manner.
A second arm 22 is pivotally mounted on the end 24 of arm 16.
The latter is pivoted in a vertical plane by a hydraulic ram 26
with respect to the turntable 18, while arm 22 is pivoted in a
vertical plane with respect to the end 2~ of arm 16 by a ram 28,
again in the conventional manner for boorns of this type. Al-
ternatively, other types of articulated extensible and adjustable
booms, could be used in the delimbing and loading apparatus of
the present invention as would occur to those skilled in the art.
The delimbing and loading head 30 of the present inven-
tion is articulated on the end 32 of the arm 22. As seen in
Figure 6, this articulation consists partially of a universal
joint 34 between the end 32 of boom arm 22 and frame 36 of head
30. The universal joint is connected to the head at approximately
its center of gravity so that it can swivel freely on the two
axes 38 and 40 and automatically remain in a substantially hori-
zontal position throughout the delimbing and loading operation.
The articulation of head 30 on the end 32 of arm 22
further consists of means by which the head can be selectively
swiveled with respect to end 32 on a third axis, through shaft
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44. This selective swiveling is accomplished through bearings
48 mounted in housing 50, hydraulic motor 46, and pin structure
42. Housing 50 and motor ~6 are rigidly mounted to frame 36.
Pin structure 42 is pivotally mounted, through pivo-t 40 and uni-
versal joint 34, to end 32 of arm 22. The weight of frame 36 is
supported on pin structure 42, through bearings 48, by a nut 49
threaded on the end of shaft 44. The shaft of motor ~6 engages
the end of shaft 44, which is hollowed out for receiving the
motor shaft. By supplying hydraulic fluid to the motor, the
operator may swivel head 30 through at least 90 and preferably
more than 360 about shaft 44.
Selective swiveling of head 30 with respect to end 32
permits the opera-tor to position the head to pick up a previously
cut tree with the support members of the invention as described
hereinafter, facilitates the placement of delimbed logs on a
transport vehicle, and facilitates the deposit of cut tree tops
in a desired location at the completion of the delimbing opera-
tion.
A further feature of the present invention is the use
of a conventional cushion valve (not ~hown) in conjunction with
motor 46 to permit the head to rotate freely about shaft 44 at
critical times. This feature has been found to be of value when,
for example, a tree being delimbed and loaded meets an obstruction
in a pile of previously loaded trees. Under these circumstances,
the obstruction will generally divert the tree from the course in
which it is being propelled by the head. If the delimbing head
is not free to adjust itself to the new, diverted path of the
tree, the tree may bind in the head, and processing will be in- -
terrupted. Such interruptions are avoided by the use of the
cushion valve, which allows the head to align itself automatically
with the changing path of travel of a tree being processed.
The delimbing head 30 of the present invention, as
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illustrated in Figures 2 and 3, includes a delimbing and tree
supporting structure 52 a-t one end of frame 36, and a shearing
or cutting appara-tus 54 at the opposite end of the frame. Located
between delimbing apparatus 52 and shearing apparatus 54 is a
drive and support structure 56 which is adapted to engage and
draw a tree trunk through delimbing apparatus 52 towards shearing
apparatus 54 so that the tree may be delimbed and its top cut off
at the completion of the delimbing operation.
The delimbing apparatus is illustrated in detail in
Figures 3 and 4. This apparatus includes a fixed top delimbing
plate 58 secured to frame 36 by an extension 60. Plate 58 in-
cludes an outer arcuate shell portion 62 having a knife edge 63.
A pair of delimbing jaws or arms 64 are pivotally mounted on
frame 36 on opposite sides of fixed delimbing shell 62. These
jaws are of essentially identical construction as seen in Figure
4, except that one of the jaws has an extention arm or bell crank
66 formed thereon. The jaws are pivotally mounted on the frame
along axes 68 which extend generally parallel to the path of
travel of the tree trunk through the apparatus; and the leading
edges 70 of the jaws are sharpened to knife edges for the purpose
of delimbing trees drawn therethrough.
Jaws 64 are normally held in their open position by a
control mechanism 74 illustrated in Figure 4. This control
mechanism includes a connecting link 76 which pivotally inter-
connects bell crank 66 to a crank member 78 secured to the other
of the jaws. In addition, control mechanism 74 includes a ~
hydraulic ram 80 which is pivotally mounted at both ends to re- ~`
spective jaw extension members 65. In the retracted position of
piston rod 82 jaws 64 are held in their open solid line position
shown in Figure 4. However, when rod 82 is extended, the jaws
are pivoted evenly to their closed, dotted line position. In
this regard, it is noted that the jaws are longitudinally offset
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from one another in the direction of travel o~ the trees through
the apparatus so that their ends will overlap to form a complete
enclosure about the tree trunk, ~hen the jaws are moved to their
closed position. This longitudinal offset relationship is also
seen most clearly in Figure 3.
In operation of the apparatus, jaws 64 are used for
picking up a tree for delimbing as well as for delimbing and
supporting the tree. To facilitate the picking up of the tree,
jaws 64 hang slightly below any other part of the delimbing and
loading head. Jaws 64 are normally held open until a tree is to
be engaged. At that time boom 14 is operated to position the de-
limbing head over the tree and a more precise position is acheived
by the operation of motor 46. When the jaws 64 are lowered about
the tree trunk they are closed by the operation of the ram 80 to
grip the tree trunk and hold it in position against the delimbing
and loading head. Thereafter the tree is moved into position for
loading and delimbing, suspended substantially horizontally over
the rear of a transport vehicle as shown in Figure lA. The drive
apparatus 56 is operated to pull the tree through jaws 64 towards
cutting apparatus 54. This movement ~ ~ls the limbs o~ the tree
past the knife edges 70 and 63 of jaws 64 and the shell 62 to
remove the limbs from the tree, and to load the tree for trans-
port.
The drive apparatus used to move the tree through the
delimbing head includes an endless belt or conveyor structure 90
mounted within frame 36 between delimbing apparatus 64 and the
shearing apparatus 54. This conveyor is trained about pairs of
sprockets 92, located at opposite ends of the frame, and is
driven through a chain drive 94 from a hydraulic motor 96.
Preferably conveyer 90 consists of a pair of parallel endless
chains 98, see Figure 2, which are interconnected to each other
by a plurality of transversely extending slats 100 connected to
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the chains in any convenient manner. These slats or ribs form a
gripping surface which engage the trunk of the tree T (see Fig-
ure 6) in a tight frictional engagement and pull the tree trunk
through the delimbing and loading head.
In order to assist conveyor 90, a pair of roller mem-
bers 102 are provided on either side of the path of travel of
the tree through the head, and on opposite sides of the conveyor.
These rollers are rotatably mounted on support structures or sub-
frames 104 which in turn are pivotally mounted on pins lS0 or the
like in any convenient manner on frame 36. In the embodiment of
the invention illustrated in Figures 2 and 3, rollers 102 are
freely rotatably mounted on subframe 104. These rollers are also
longitudinally ofEset from one another, and their relative posi-
tion with respect to each other is controlled by a pair of rams
106, respectively controlling subframes 104. These rams have
their casings pivotally mounted onframe 36 at 108 and their piston
rods pivotally secured by pins 112 or the like to subframe 104.
In the retracted position of the piston rods 110 rollers 102 are
helcl in spaced generally parallel relat.ionship to one another, as
seen in Figure 2. However, when a tree trunk is engaged by the
delimbing claws 6~, rams 10~ are operated to extend piston rods
110 and pivot the rollers about pins 150, so that the rollers ~;
move into an angular position with respect to each other as seen
for example in Figure 6. In this position the rollers support
the tree against conveyor 90 and the slats 100 thereof to insure `
a proper frictional engagement between the tree and the bars so
that the drive conveyer will draw the tree through the delimbing
jaws 6~ with sufficient force for proper delimbing to occur. ~i
A guide member 134 is rigidly attached to frame 36 to
stop any twisting action of the tree caused during the inltial
delimbing stage hy the pressure of offset rollers 102.
After the desired length of the tree has been passed ~ ;
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through the delimbing jaws the drive conveyor gO can be stopped,
and the remaining portion of the tree severed from the usable
portion previously delimbed. This severing operation is achieved
by the shearing or cutting apparatus 54. This apparatus includes
a pair of jaws 120 pivotally mounted on frame 36 by pivot pins
122 or the like in any convenient mannex. Each cutting jaw has
a knife edge 124 formed thereon and a bell crank 126 extending
therefrom. These cranks are respectively pivotally connected to
piston rods 128 of hydraulic cylinders 130. The latter have
their casings pivotally mounted at 132 on frame 36. By this con-
struction, upon contraction of piston rods 128 into casings 130,
cutting jaws 120 will be held in their open dotted line position
illustrated in Figure 5; but upon extension of the piston rods,
the jaws will move, as indicated by the arrow in Figure 5, to-
wards a closed position to shear off any portion of the tree
trunk T therebetween.
As previously discussed, while the delimbing operation
is taking place the boom may be moved by the operator to position
the cut end 140 of the tree over a transport vehicle 142 or the
like, so that while the delimbing operation proceeds the tree
trunk will be urged into proper position on the transport vehicle.
When the delimbing operation is completed the tree top T' is
severed by operation of the cutting jaws, and the tree trunk
falls into proper position on the transport vehicle. However,
the tree top T' remains supported in the delimbing head, as illus-
trated in Figure lA, since it is captured between the delimbing
jaws 64 and between the rollers 102. Thus a firm grip is main-
tained on the tree top and the boom can be operated to place the
tree top in a desired disposal location. This procedure saves a
substantial amount of man time in moving and disposing of these
tree tops which are unwieldly to handle manually. Moreover, this
procedure speeds the delimbing and harvesting operation, since
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the delimbing site is ~aintained clear and available far delimb-
ing of fur-ther tree trunks in rapid succession.
In a modified embodiment of the invention illustrated
in Figure 6 rollers 102 are provided as drive rollers. In this
case each roller has a pair of spaced end faces 140 rigidly
interconnected by a plurality of bars 142 which may have sharp-
ened edges to insure a tight frictional engagement with the tree
T. In this case, frame 104, which is similar to the frame 104
previously described and on which the rollers 102 are rotatably
mounted, has mounted on it, in addition, a hydraulic motor 144.
This hydraulic motor is connected through a chain 146 to its
associated roller 102, so that after the rollers are pivoted ;
into position to hold and support the tree trunk T against con-
veyor 90, the motors 144 can be operated in conjunction with the
conveyor motor 96, to provide additional driving force against -
the tree trunk to insure that it is pulled through the delimbing
jaws with sufficient force.
It has been found that by use of the invention in its `; s
above-described modified embodiment, two previously-cut trees ;
can be satisfactorily delimbed, topped and loaded simultaneously. ~ -
To accomplish the simultaneous processing of two trees, the oper-
ator need only position the delimber head 30 so that jaws 64 are
lowered and closed up about two generally parallel tree trunks.
Thereafter, the processing continues as described in reference
to a single tree.
It is noted that the various elements of the present ~-~
invention are operated entirely through hydraulic motors and the
like. The specific hydraulic circuitry used to operate the var-
ious rams and motors is of conventional construction and would be ;~
apparent to those skilled in the art, in view of the above des-
cription of the operations -thereof. Accordingly a detailed des-
cription of the specific hydraulic circuit is not deemed necess~
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ary in this case. Alternatively~ it is contemplated that in
lieu of the hydraulic drive mechanism used herein, pneumatic or
electric motors and the like can also be used.
Althou~h an illustrative embodiment of the present in-
vention has been described herein with reference to the accom-
panying drawings, it is to be understood that the invention is
not limited to that precise emhodiment, and that various changes
and modifications may be effected therein by one skilled in the
art without departing from the scope or spirit of this invention.
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