Ergonomics - Atlas Copco

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Working environment
In general, drills have a low impact on the
working environment, particularly the
small models. Large drills can be somewhat
noisy. Most drills do not require lubrication.
Design for good ergonomics
The load on the operator depends on the size
of the hole to be drilled. If a larger hole is to
be drilled, more feed force must be applied
to the machine by the operator. Larger holes
can be pre-drilled to reduce the feed force.
The type of grip chosen will influence
the operator’s posture. A drill with a pistol
grip conveys feed forces more efficiently than
straight or angle grip drills.
The handle must be designed to mini-
mize the torque absorbed by the wrist when
high feed forces are needed.
The pistol grip should allow the operator
to change his hold on the machine. He should
hold the machine lower down the handle
when applying a small feed force and higher
up when high feed force is required. The high
position should result in a straight line from
the center line of the machine to the bones
in the operator’s forearm. The torque in the
operator’s wrist should be kept as low as
possible at all times.
The straight handle should only be
used when low feed forces are required,
particularly where a vertical hole is to be
drilled in a workpiece. If high feed forces
are necessary, a pistol grip machine may be
used, provided the operator can work with
his wrist held straight. If the hole requires
a bent wrist posture, the position of the
workpiece should be rearranged so that the
operator can work with a straight wrist.
The combination of bent wrist and high feed
forces should always be avoided.
The angle grip is used mainly for drill-
ing in cramped spaces. The feed force
needed should preferably be applied using
both hands.
The wrist’s capability to provide ulnar
flexion torque is limited and one-handed
operation of angle drills should be avoided.
Safety
Drills are not generally a risk. However, if
the operator holds the drill bit and starts the
tool he will damage his hand. Some drills
have a guard covering the chuck, but the
drill bit cannot be guarded easily. The guard
allows a comfortable two-handed grip.
When working with larger drill bits,
there is always the risk of a jerk when the
drill bit penetrates the workpiece, resulting
in a shock reaction which is absorbed by the
operator’s wrist. Most of the feed force is
applied to the point of the bit to help it work