14
ADDITIONAL SAFETY DEVICES DESIGNED TO REDUCE THE RISK OF INJURY
FROM KICKBACK
Your ECHO chain saw and its operator’s manual have been certified 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 specific 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 ECHO 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. ECHO
chain saws combine both hand guard lever and inertia chain brakes. Review your
instruction manual or contact ECHO to find out the specifications of your saw model.
Chain Brake
Lever
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, or stopping times may become
inconsistent. Eventually, a major rebuild or complete replacement of the chain brake may be required for the chain brake
to meet the ANSI B175.1 Standard.
The following may interfere with the chain brake’s ability to reduce the risk of injury to the operator:
•
Saw wrongly held too close to operator’s body (no fault of the brake). Kickback may occur faster than
a perfectly maintained brake can be activated.
•
The operator’s hand may not be in position to contact the hand guard. Brake will not be tripped.
•
In the case of certain kickbacks, such as in a low intensity kickback, the inertia brake may not activate
as intended because forces are below the required activation level.
Loss of control of the saw still
may occur!
•
Lack of proper maintenance increases the chain brake’s stopping time, making it less effective.
•
Dirt, grease, oil, pitch, etc. getting into the working parts of the mechanism may increase the stopping
time or render the chain brake inoperable.
