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Procedure to complete the risk assessment
1. Determine the following information
Machine
installation
date
……….
Date of last window change
……….
Maximum cutter outside diameter, including manually
……….mm
loaded tools, d
max
Maximum tip mass, m
max
……….kg
If this value is less than 0.1kg, then use 0.1
Maximum spindle speed, s
max
……….rpm
2. Calculate the following
Cutter periphery speed, v
(
π
d
max
s
max
) / 60000
……….m/s
Possible projectile energy, J
0.5 m
max
v
2
……….Joules
3. Determine the impact resistance of the window from the appropriate graph.
Impact
resistance,
J
(from the graph)
……….Joules
4. Determine the risks.
Compare the calculated energy of the potential projectile against the window impact
resistance energy. It is always sensible to allow a safety margin within the
comparison. A 30% safety margin should be used as an absolute minimum.
If you have any doubts about your use of this procedure contact your local
Hardinge representative or Service Department for advice and help.
It is
important that the person responsible for safety within the factory (Safety
Officer) should consider the actual cutting process being undertaken on the
machine, and ensure that the guard gives complete protection.
If a workpiece, fixture etc files out and breaks a window or cover, or if a window
or cover is scratched by chips and some of the normal field of view is lost,
replace the window or cover as soon as possible. Note that once a window and
cover have been subject to a strong impact, their safety can no longer be
guaranteed even though they may appear to be unaffected.
When changing a window and cover, be sure to contact your machine tool
supplier and use the specified product at the time the order is placed. Your
Machine tool supplier cannot accept responsibility for any trouble arising from
the use of a window and cover not to specification.
If you operate the machine while a window or cover is damaged, a workpiece,
chips or coolant may fly out through the damaged window or cover.
If some of the normal field of view is lost, it will not be possible to properly
ascertain the status of the machine during machining and setup work. This
could cause accidents involving serious injuries or damage to the machine.
