Tree gripping device

A tree gripping device adapted to be mounted on the top of a bulldozer blade. The device has a base member mounted on top of the blade, the base member projecting past one side of the blade. A gripping arm is pivotally mounted on the projecting portion of the base member, the arm extending along the side of the blade. Actuating structures move the gripping arm toward the side of the blade to grip a tree between them.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The invention is directed toward an improved tree gripping device. 
The tree gripping device is specifically designed to be mounted on a 
bulldozer blade so that the bulldozer can be used to transport trees. 
2. Description of the Prior Art 
In harvesting trees in a forest, the trees are felled, possibly delimbed at 
the felling site, and then transported from the felling site for further 
processing. The trees are often transported by dragging bundles of the 
trees, by their butt ends. Often one or more trees drop out of the bundle 
as they are being dragged. The cost of retrieving these dropped trees, 
using existing forestry equipment, is quite expensive and usually the 
trees are left lying on the ground where they drop. 
In many tree harvesting operations, bulldozers are employed to collect the 
cut-off limbs, to build roads, and to perform other tasks. It is known to 
provide a tree gripping device on the side of the blade on the bulldozer 
so that the bulldozer can be used to collect any trees that drop during 
transport of the trees. A bulldozer equipped with such a tree gripping 
device can economically collect the dropped trees one or two at a time 
thereby improving profitability. 
U.S. Pat. No. 4,645,410 discloses a bulldozer with a blademounted tree 
gripping device. The gripping device operates satisfactorily. However, it 
does have some disadvantages. The hydraulic actuator, which operates the 
gripping device, is located in a relatively exposed position on the side 
of the blade and it, and the line connections to it, can be easily damaged 
during normal operation of the bulldozer. Also, the gripping device 
employs both a fixed jaw and a movable jaw, which makes the device 
expensive. 
SUMMARY OF THE INVENTION 
It is the purpose of the present invention to provide a tree gripping 
device adapted to be mounted on a bulldozer blade which is simpler and 
cheaper to construct than the known gripping device, and which also is 
constructed to locate the actuator means in a more protective position on 
the blade. In accordance with the present invention, the gripping device 
has the actuating means located on the top of the bulldozer blade where it 
is more protected during normal use of the bulldozer. Cover means can be 
mounted on the bulldozer blade, overlying the actuator means, to further 
protect it. Also in accordance with the present invention, the gripping 
device is provided with a single movable jaw. The single jaw cooperates 
with the side of the blade to grip a tree between them. Eliminating the 
fixed jaw simplifies the gripping device making it cheaper to manufacture. 
The invention is particularly directed toward a tree gripping device 
adapted to be mounted on the top of a bulldozer blade. The device 
comprises an elongate base member for attachment in a generally horizontal 
position on the top of, and aligned with, the bulldozer blade with one end 
of the base member projecting past one side of the blade. A gripping arm 
is pivotally attached near one of its ends to the base member adjacent its 
one end. The gripping arm extends generally transverse to the base member 
and is located adjacent the one side of the blade with its other free end 
near the ground when the base member is mounted on top of the bulldozer 
blade. 
Actuating means, generally overlying the base member, are pivotally 
attached adjacent one end to the gripping arm adjacent its one end and 
adjacent its other end to one of the base member and the top of the 
bulldozer blade. The actuating means operates to move the gripping arm to 
grip a tree lying on the ground between the gripping arm adjacent its free 
end and the said one side of the bulldozer blade.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
The tree gripping device 1 of the present invention, as shown in FIGS. 1 to 
3, is adapted to be mounted on the blade 3 of a bulldozer 5. The blade has 
top and bottom sides 7, 9 and end sides 11, 13. The tree gripping device 1 
is mounted on the top side 7 of the blade 3. 
The tree gripping device 1 has an elongate base member 15 having a first 
end 17 and a second end 19. The gripping device 1 also has a tree gripping 
arm 21 having a first end 23 and a second end 25. The arm 21 has a hook 
shaped portion 27 near its second end 25. The gripping arm 21 is pivotally 
connected, near its first end 23, to the base member 15 adjacent its first 
end 17, by a pivot member 29. The gripping arm 21 extends generally 
transverse to the base member 15. 
The gripping device 1 also has actuating means 31 for pivoting the gripping 
arm 21 relative to the base member 15 about pivot member 29. The actuating 
means 31 preferably comprises a hydraulic actuator 33 having a piston rod 
35 projecting from one end 37 of a cylinder 39. One end of the actuator 
33, the free end 41 of the piston rod 35 for example, is pivotally 
connected adjacent the first end 23 of the tree gripping arm 21 by a pivot 
member 43. The other end of the actuator 33, the other end 45 of cylinder 
39 for example, is pivotally connected to the base member 15 adjacent its 
second end 19 by a pivot member 47. The actuator 33 generally overlies the 
base member 15 and is positioned relatively close to the top surface 49 of 
the base member. 
The gripping device 1 is mounted on the top side 7 of the blade 3 at one 
end side 11. The base member 15 is mounted on the top side 7 of the blade 
3, parallel with the blade, with its first end 17 projecting just past the 
one end side 11. The base member 15 can be welded or otherwise suitably 
fixed to the blade 3. The gripping arm 21 extends downwardly from the base 
member 15 adjacent the one end side 11 of the blade 3. The second, free 
end 25 of the gripping arm 21 is close to the ground when the device 1 is 
mounted on the blade. 
In the operative position, the free end 25 of the gripping arm 21 is 
normally positioned close to the end side 11 of the blade 3. When it is 
desired to pick up a tree lying on the ground with the bulldozer, the 
bulldozer is maneuvered to place the blade 3 above the butt end of the 
tree with the gripping arm 21 directly over the tree. The actuator 33 is 
operated to move the free end 25 of the gripping arm 21 away from the 
blade 3 and the blade 3 is then lowered to place the tree butt end "T" 
between the gripping arm 21 and the blade 3. The actuator 33 is again 
operated to move the free end 25 of gripping arm 21 toward the blade 3 to 
pin the butt end between the gripping arm 21, in its hook-shaped portion 
27, and the blade side 11. The bulldozer blade 3 can now be raised, and 
the bulldozer operated to move the tree. 
If desired, a stop member 53 can be mounted on the one end side 11 of the 
blade 3 about midway between its top and bottom sides 7, 9 as shown in 
FIGS. 2 and 3. The stop member 53 extends laterally from the blade 3 and 
prevents the butt end of the tree from riding up the one side 11 of the 
blade as the gripping arm 21 is moved toward the blade 3 to grip the tree. 
A protective cover 55, as shown in FIGS. 2 and 3, supported at its ends by 
legs 57 can be mounted on the blade 3 over the actuator 33 to protect it. 
While the other end 45 of the actuator 33 has been shown as being mounted 
on the base member 15, the other end 45 of the actuator can also be 
mounted directly on the top side 7 of the blade 3 via brackets 59 fixed 
thereon, and via a pivot member 61 as shown in FIG. 4. This can permit the 
use of a shorter base member 15. 
The gripping device 1 has been shown with a single gripping arm 21. It 
could also employ twin gripping arms, one on each side of the blade. As 
shown in FIG. 5 two gripping arms 21A, 21B are mounted, one on either side 
of member 15, by pivot member 29. The first ends 23A, 23B of the gripping 
arms 21A, 21B are joined by pivot member 43. The one end 41 of the 
actuator 33 is pivotally mounted on pivot member 43 between the first ends 
23A, 23B of the gripping arms 21A, 21B. Operation of actuator 33 will move 
the gripping arms 21A, 21B to securely grip a tree between the arms and 
the blade 3. If desired, the side 11 of the blade 3 can be notched or 
otherwise cut away to allow the free ends 25A, 25B of the gripping arms 
21A, 2lB to pass past the side 11 of the blade.