Safety Manual

17
ENGLISH
KICKBACK/ OPTIONAL KICK GUARD
TM
Additional Safety Devices Designed to Reduce the
Risk of Injury from Kickback
Your chain saw and its operator’s manual have been certied to meet
the requirements of Voluntary Standard B175.1 of the American National
Standards Institute (ANSI). B175.1 sets forth the minimum safety requirements
for the manufacture of gasoline-powered chain saws.
ANSI B175.1 addresses rotational kickback, which can occur when the chain
saw tip contacts an object and propels the saw upward and rearward toward
the operator at rapid speeds. Kickback can cause severe and even fatal
injuries. ANSI B175.1 requires that chain saws with an engine displacement
of under 3.8 cubic inches (62.3CC) have a maximum Computed Kickback
Angle (CKA) no greater than 45 degrees. CKA is computed (under laboratory
conditions) from a kickback test machine, plus other data including the
dimensions of the chain saw. Any deviation from laboratory conditions may
result in a higher CKA; and thus require chain saws in this class to have at
least two of the following devices to reduce the risk of injury from kickback:
anti-kick tip guard which mounts at the nose of the guide bar, chain brake,
reduced kickback chain, or reduced kickback guide bar. Learn which specic
devices are included on your saw model.
CHAIN BRAKE:
When activated, this device is intended to stop
the saw chain rotation immediately after a
kickback has occurred. A chain brake does not
prevent kickback.
The chain brake can be activated both manually
and automatically. Manual chain brake
engagement occurs if the operator’s left hand or wrist applies a force against
the front hand guard, which is part of the brake lever. Automatically activated
chain brakes are intended to respond to kickback accelerations without brake
lever contact. These are sometimes called inertia brakes, which respond to a
certain level of acceleration, and do not require manual activation by the hand
guard lever. Chain saws combine both hand guard lever and inertia chain
brakes. Review your instruction manual or contact ECHO Incorporated to nd
out the specications of your saw model.
WARNING! It is the responsibility of the owner or operator to ensure
that the brake is serviced, adjusted, and tested in accordance with the
instructions as detailed in your instruction manual in order to ensure that the
brake performance is maintained in compliance with ANSI B175.1- 2000, which
stipulates that the brake shall stop the chain in a maximum of 0.15 seconds
after activation (0.12 Average).
WARNING! Do not rely on the chain brake for protection against
kickback. The chain brake may never activate; and even if it does, its chain-
stopping capability, even under ideal conditions, may not be fast enough to
prevent injury to the operator due to the rapid dynamics of a kickback.
Even with a chain brake, depend on your own good sense and proper cutting
methods just as though there were no chain brake. Additionally, even with
normal use and proper maintenance, the initial stopping time of the chain brake
may increase, or the chain brake may become incapable of stopping the saw
Chain Brake
Lever