Stihl HT 102 Product Instruction Manual - Page 13

Reactive Forces, WARNING, Kickback, To Avoid Kickback, A = Pull-in, To Avoid Pull-in, B = Pushback

Page 13 highlights

muffler maintained by a STIHL servicing dealer. Some state or federal laws or regulations may require a properly maintained spark arrestor for certain uses. See the "Maintenance, Repair and Storing" section of these Safety Precautions. Remember that the risk of a brush or forest fire is greater in hot or dry conditions. Reactive Forces WARNING Reactive forces may occur any time the chain is rotating.The force used to cut wood can be reversed and work against the operator. If the rotating chain is suddenly stopped by contact with any solid object such as a branch or is pinched, the reactive forces may occur instantly. These reactive forces may result in loss of control, which, in turn, may cause personal injury. An understanding of the causes of these reactive forces may help you avoid the element of surprise and loss of control. Because of the design of the pole pruner, the reactive forces experienced when working with it are generally not as severe as those encountered with a chainsaw. Nevertheless, you should always maintain a proper grip and good footing to control the power tool when you experience such forces. The most common reactive forces are: - kickback, - pushback, - pull-in. Kickback Kickback may occur when the moving saw chain near the upper quadrant of the bar nose contacts a solid object or is pinched. The reaction of the cutting force of the chain causes a rotational force on the pole pruner in the direction opposite to the chain movement. This may cause the bar to move upward. To Avoid Kickback The best protection from kickback is to avoid kickback situations: 1. Be aware of the location of the guide bar nose at all times. 2. Never let the nose of the guide bar contact any object. Do not cut limbs with the nose of the guide bar. Be especially careful near wire fences and when cutting small, tough limbs, which may easily catch the chain. 3. Cut only one limb at a time. A = Pull-in 002BA230 KN 001BA037 KN English A Pull-in occurs when the chain on the bottom of the bar is suddenly stopped when it is pinched, caught or encounters a foreign object in the wood. The reaction of the chain pulls the pole pruner forward. Pull-in frequently occurs when the chain is not rotating at full speed before it contacts the wood. To Avoid Pull-in 1. Be alert to forces or situations that may cause material to pinch the chain at the bottom of the bar. 2. Always start a cut with the chain rotating at full speed. B = Pushback B Pushback occurs when the chain on the top of the bar is suddenly stopped when it is pinched, caught or encounters a foreign object in the wood. The reaction of the chain may drive the pole pruner rapidly straight back toward the 001BA038 KN HT 102, HT 103, HT 132, HT 133 11

  • 1
  • 2
  • 3
  • 4
  • 5
  • 6
  • 7
  • 8
  • 9
  • 10
  • 11
  • 12
  • 13
  • 14
  • 15
  • 16
  • 17
  • 18
  • 19
  • 20
  • 21
  • 22
  • 23
  • 24
  • 25
  • 26
  • 27
  • 28
  • 29
  • 30
  • 31
  • 32
  • 33
  • 34
  • 35
  • 36
  • 37
  • 38
  • 39
  • 40
  • 41
  • 42
  • 43
  • 44
  • 45
  • 46
  • 47
  • 48
  • 49
  • 50
  • 51
  • 52
  • 53
  • 54
  • 55
  • 56
  • 57
  • 58
  • 59
  • 60
  • 61
  • 62
  • 63
  • 64
  • 65
  • 66
  • 67
  • 68
  • 69
  • 70
  • 71
  • 72
  • 73
  • 74
  • 75
  • 76
  • 77
  • 78
  • 79
  • 80
  • 81
  • 82
  • 83
  • 84
  • 85
  • 86
  • 87
  • 88
  • 89
  • 90
  • 91
  • 92
  • 93
  • 94
  • 95
  • 96

HT 102, HT 103, HT 132, HT 133
English
11
muffler maintained by a STIHL servicing
dealer. Some state or federal laws or
regulations may require a properly
maintained spark arrestor for certain
uses. See the "Maintenance, Repair and
Storing" section of these Safety
Precautions. Remember that the risk of
a brush or forest fire is greater in hot or
dry conditions.
Reactive Forces
WARNING
Reactive forces may occur any time the
chain is rotating.The force used to cut
wood can be reversed and work against
the operator. If the rotating chain is
suddenly stopped by contact with any
solid object such as a branch or is
pinched, the reactive forces may occur
instantly. These reactive forces may
result in loss of control, which, in turn,
may cause personal injury. An
understanding of the causes of these
reactive forces may help you avoid the
element of surprise and loss of control.
Because of the design of the pole
pruner, the reactive forces experienced
when working with it are generally not as
severe as those encountered with a
chainsaw. Nevertheless, you should
always maintain a proper grip and good
footing to control the power tool when
you experience such forces.
The most common reactive forces are:
kickback,
pushback,
pull-in.
Kickback
Kickback may occur when the moving
saw chain near the upper quadrant of
the bar nose contacts a solid object or is
pinched.
The reaction of the cutting force of the
chain causes a rotational force on the
pole pruner in the direction opposite to
the chain movement. This may cause
the bar to move upward.
To Avoid Kickback
The best protection from kickback is to
avoid kickback situations:
1.
Be aware of the location of the guide
bar nose at all times.
2.
Never let the nose of the guide bar
contact any object. Do not cut limbs
with the nose of the guide bar. Be
especially careful near wire fences
and when cutting small, tough
limbs, which may easily catch the
chain.
3.
Cut only one limb at a time.
A = Pull-in
Pull-in occurs when the chain on the
bottom of the bar is suddenly stopped
when it is pinched, caught or encounters
a foreign object in the wood. The
reaction of the chain pulls the pole
pruner forward.
Pull-in frequently occurs when the chain
is not rotating at full speed before it
contacts the wood.
To Avoid Pull-in
1.
Be alert to forces or situations that
may cause material to pinch the
chain at the bottom of the bar.
2.
Always start a cut with the chain
rotating at full speed.
B = Pushback
Pushback occurs when the chain on the
top of the bar is suddenly stopped when
it is pinched, caught or encounters a
foreign object in the wood. The reaction
of the chain may drive the pole pruner
rapidly straight back toward the
002BA230 KN
001BA037 KN
A
001BA038 KN
B