Note: Descriptions are shown in the official language in which they were submitted.
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S ~ E C I F I C A_T I 0 N
This inven-tion consists of front and rear lift mecha-
nism or jacks for machines used in handling of logs in the for-
est where they are first cut. These machines are actually heavy
duty tr~ctors specially designed for dragg;ng logs from the
areas where they are first cut to the storage area for their
next stage of transportation. They are commonly referred to as
"Skidders".
The terrain upon which the skidders operate is usually
virgin ground covered with deep layers of snow in the winter
time and is wet and soggy in the spring and summer. The skidder,
which is a very heavy tractor, quite often becomes stuck in the
ground, and it becomes necessary to pull it out of the rut be-
fore it can continue to operate. Because of the weight of the
skidder and the nature of the ground, conventional jacks have
been found inoperative.
The usual procedure employed in raising a skidder out
of a rut consists of using a heavy cable from a winch on the
skidder, which passes under its frame and the end of which is
then tied to the nearest suitable tree. By rewinding the winch,
the stuck end of the skidder is pulled and raised, at the same
time, and released from the rut.
This method is very effec-tive, however, it is very
costly in material, labor, and lost time, because quite often,
the cable which is at times three quarters of an inch in diameter
gets damaged or breaks due to its contact with the skidder frame
under an extremely high tension; this involves the replacement
of the cable, labor cost, and the lose of valuable time.
The primary object of this invention is therefore to
eliminate the contact of the cable with any sharp edges, thereby
eliminating the damage to the cable and all other expenses
involved.
In describing the invention reference will be made
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to the attached drawings in whichl-
Fîgure 1, is a plan view of the rear skidder jack,
Figure 2, is a front elevation of the rear skidder
jack,
Figure 3, is a plan view of the front skidder jack,
Figure 4, is a front elevation of the front
skidder jack,
Figure 5, is a diagram showing the method of applying
the rear jack, and
Figure 6, is a diagram showing the application o~
the front jack.
The rear jack A is made of heavy steel plate, pre-
ferably of three quarters inch thickness: it consists of a
rectangular back plate 2, from the face of which extend at
rightangles two spaced shorter plates 3,3, which are located
symmetrically about the center of the plate 2~ A brace 4 is
provided between the back plate 2 and each of the extensions 3.
The plate 2 is also provided with a plurality of bolt holes 5
by means of which the rear jack A is attached to the bottom
framework or body of the skidder 22. At the front ~nd bottom
o~ the plates 3,3, is located a roller 6 which is parallel to
the back plate 2, and is free to rotate within the plates 3,3.
A similar roller 6 is spaced from the roller 6, parallel, and
in line with it at the rear o~ the plates 3,3. Two side rollers
8~8, are each attached to the inner faces of the plates 3, are
free to rotate within their supporting blocks 8 they are smaller
in diameter~ spaced from and at right angles to the rollers
6 and 6 . An upper rear roller 7, smaller in diameter than,is
spaced from, and at right angles to the rollers 8, The rollers
6,6',7, and 8 are held within their supports by a circular boss
12, and a retaining ring 11, and are provided with lubrication
fittings 9. The back plate 2 is provided with an indentation
10 for the purpose of clearing the cable 24 as will be described
in connection with Figure 6,
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The front jack B, consists of a back plate 13 to
which is centrally attached a rectangular box 15 which has an
open face and an open baok. Centrally located on the back
plate 13 is a U-shaped cut out area 14 to permit the passage
therethrough of the cable 24 (see Fig.6). Holes 16 are pro
vided in the back plate 13, as means for attaching the ~ack B
to the skidder. A centrally located horizontal roller 17 ro-
tates freely in the said box 15, and a vertical free rotating
roller 18 is located at the rear of and close to each vertical
side of the box 15. The rollers 17 and 18 are held within the
box 15 by bosses 19, and retaining rings 20, and the rollers
are lubricated by lubrication fittings 21.
In Figure 5 is shown the procedure for freeing the
rear wheels of the skidder 22 from a rut 27. The skidder is
15 equipped with a power operated winch 23 and a winch idler rol-
ler 23 located away and above the winch. A cable 24 which
is normally wound upon said winch, runs over the idler 23 ,
down to and between the jack roller 6 and 6 , wraps under and
against the roller 6, and continues on to be tied to the nearest
available tree 25 as shcwn. By rotating the winch in the pul-
ling direction, the cable is tightened, thus raising the skidder
and its rear wheels out of the rut.
In Figure 6 is æhown the method of freeing the front
wheels when they are bogged down. In this case, the cable 24
from the idler 23 goes down between the rollers 6 and 6' and
wraps under and against the roller 6' and also against the rol-
ler 7. The cable 24 then runs under the skidder to the roller
17 in the front jack B. It presses tightly against the bottom
of the roller 17 and is tied to the nearest available tree 26.
~0 By activating the said winch, the front of the skidder with
its wheels are raised out of the rut.
The vertical rollers 8,8, in the jack B and the
vertical rollers 18,18, in the jack A serve the purpose of
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having the cabJe 24 rub agains-t them when the tied cable is
at an angle to the skidder.
This invention besides acting as a jack as above
described, can also be used for dragging a number of cut logs
along a rugged ground by tying the ends of the logs to the
cable, along its length, or for pulling large structures for
relocation. As a safety feature, the use of this invention
eliminates cable burn to the hands of workmen on the job.
Various modifications of the above described
embodiments of the invention will be apparent to those skilled
in the art, and it is to be understood that such modi~ications
can be made without departing from the scope of the invention,
if they are within the spirit and the tenor of the accompanying
claims.
1~
Charles Krassov
220 McEwan Avenue
Windsor, Ontario, Canada. N9B 2E4.
Patent Attorney for the Applicant.
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