Hitachi Koki CS 33EDT Bedienungsanleitung Seite 12

English
WARNING
Do not stand in-line with chain when cutting.
BASIC TECHNIQUES FOR MAKING FELLING, LIMBING AND
BUCKING CUTS
The intention of the following information is to provide you with the
general introduction to wood cutting techniques.
WARNING
○ This information does not cover all specifi c situations, which may
depend on diff erences in terrain, vegetation, kind of wood, form and
size of trees, etc. Consult your servicing dealer, forestry agent or
local forestry schools for advice on specifi c woodcutting problems
in your area. This will make your work more effi cient and safer.
○ Avoid cutting in adverse weather conditions, such as dense fog,
heavy rain, bitter cold, high winds, etc.
Adverse weather is often tiring to work in and creates potentially
dangerous conditions such as slippery ground.
High winds may force the tree to fall in an unexpected direction
causing property damage or personal injury.
CAUTION
Never use a chain saw to pry or for any purpose for which it is not
intended.
WARNING
○ Avoid stumbling on obstacles such as stumps, roots, rocks,
branches and fallen trees. Watch out for holes and ditches. Be
extremely cautious when working on slopes or uneven ground.
Shut off the saw when moving from one work place to another.
Always cut at wide open throttle. A slow moving chain can easily
catch and force the saw to jerk.
○ Never use the saw with only one hand.
You cannot control the saw properly and you may lose control
and injure yourself severely.
Keep the saw body close to your body to improve control and
reduce strain.
When cutting with the bottom part of the chain the reactive force
will pull the saw away from you towards the wood you are cutting.
The saw will control the feeding speed and sawdust will be
directed towards you. (Fig. 19)
○ When cutting with the upper part of the chain the reactive force
will push the saw towards you and away from the wood you are
cutting. (Fig. 20)
○ There is a risk of kickback if the saw is pushed far enough so that
you begin to cut with the nose of the bar.
The safest cutting method is to cut with the bottom part of the
chain. Sawing with the upper part makes it much more diffi cult to
control the saw and increases the risk of kickback.
○ In case the chain locked, immediately release the throttle trigger.
If the throttle trigger keeps rotating at high speed with the chain
locked, the clutch will overheat causing trouble.
NOTE
Always keep the spiked bumper face to a tree, because the
chain may suddenly be drawn into a tree.
FELLING
Felling is more than cutting down a tree. You must also bring it down
as near to an intended place as possible without damaging the tree
or anything else.
Before felling a tree, carefully consider all conditions which may
eff ect the intended direction, such as:
Angle of the tree. Shape of the crown. Snow load on the crown.
Wind conditions. Obstacles within tree range (e.g., other trees,
power lines, roads, buildings, etc.).
WARNING
○ Always observe the general conditions of the tree. Look for
decay and rot in the trunk which will make it more likely to snap
and start to fall before you expect it.
○ Look for dry branches, which may break and hit you when you
are working.
Always keep animals and people at least twice the tree length
away while felling. Clear away shrubs and branches from around
the tree.
Prepare a path of retreat away from the felling direction.
11
BASIC RULES FOR FELLING TREES
Normally the felling consists of two main cutting operations, notching
and making the felling cut. Start making the upper notch cut on the
side of the tree facing the feeling direction. Look through the kerf as
you saw the lower cut so you do not saw too deep into the trunk. The
notch should be deep enough to create a hinge of suffi cient width
and strength. The notch opening should be wide enough to direct
the fall of the tree as long as possible. Saw the felling cut from the
other side of the tree between one and two inches (3–5 cm) above
the edge of the notch. (Fig. 21)
19. Felling direction
20. 45° minimum notch opening
21. Hinge
22. Felling cut
Never saw completely through the trunk. Always leave a hinge.
The hinge guides the tree. If the trunk is completely cut through, you
lose control over the felling direction.
Insert a wedge or a felling lever in the cut well before the tree
becomes unstable and starts to move. This will prevent the guide
bar from binding in the felling cut if you have misjudged the falling
direction. Make sure no people have come into the range of the
falling tree before you push it over.
FELLING CUT, TRUNK DIAMETER MORE THAN TWICE GUIDE
BAR LENGTH
Cut a large, wide notch. Then cut a recess into the center of the
notch. Always leave a hinge on both sides of the center cut. (Fig. 22)
Complete the felling cut by sawing around the trunk as in the Fig. 23.
WARNING
These methods are extremely dangerous because they involve
the use of the nose of guide bar and can result in kickback.
Only properly trained professionals should attempt these
techniques.
LIMBING
Limbing is removing the branches from a feller tree.
WARNING
A majority of kickback accidents occur during Iimbing.
Do not use the nose of the guide bar. Be extremely cautious and
avoid contacting the log, other limbs or objects with the nose
of the guide bar. Be extremely cautious of limbs under tension.
They can spring back towards you and cause loss of control
resulting in injury. (Fig. 24)
Stand on the left side of the trunk. Maintain a secure footing and rest the
saw on the trunk. Hold the saw close to you so that you are in full control
of it. Keep well away from the chain. Move only when the trunk is between
you and the chain. Watch out for spring back of limbs under tension.
LIMBING THICK BRANCHES
When limbing thick branches, the guide bar may get pinched easily.
Branches under tension often snap up, so cut troublesome branches
in small steps. Apply the same principles as for cross cutting. Think
ahead and be aware of the possible consequences of all your actions.
CROSS CUTTING/BUCKING
Before starting to cut through the log, try to imagine what is going to
happen. Look out for stresses in the log and cut through it in such a
manner that the guide bar will not get pinched.
CROSS CUTTING LOGS, PRESSURE ON TOP
Take a fi rm stance. Begin with an upper cut. Do not cut too deeply,
about 1/3 of the log diameter is enough. Finish with a bottom cut.
The saw cuts should meet. (Fig. 25)
23. Relieving cut
24. Cross cut
25. Pressure on top
26. Pressure side
27. Tension side
28. Relative depth of saw cuts
THICK LOG, LARGER THAN GUIDE BAR LENGTH
Begin by cutting on the opposite side of the log. Pull the saw towards
you, followed by previous procedure. (Fig. 26)
If the log is lying on the ground make a boring cut to avoid cutting into
the ground. Finish with a bottom cut. (Fig. 27)