(5) When unexpected motion would cause injury, precautions shall be taken to
prevent a machine from automatically restarting upon the restoration of power after a
power failure .
(6) Where a machine work station is remotely located from the machine controls,
either a red emergency stop device shall be provided at the machine work station if a
hazard exists that could cause an injury or the actuation of the controls shall require
continuous depression during the hazardous portion of the machine cycle .
(7) Equipment that is operated in series so that one piece of equipment
automatically supplies another shall be interlocked so that when any equipment in the
series is stopped for any reason, the initial stopping causes the upstream equipment to
stop if continued operation would create a hazard. Reactivation shall require a separate
positive action by the employee who initiated the stop .
History: 1979 AC; 1993 AACS.
R 408.10034 Machine guards and devices.
Rule 34. (1) Two hand-control devices shall be the anti-tie down type and located in
a manner to prevent bridging. Operation shall require manual activation of both controls
until a point is reached in the cycle where the operator cannot remove his or her hands
and place them within a pinch point. If repeating would cause an injury, an anti-repeat
device shall be incorporated into the control system.
(2) Guards shall be secured to the machine, if possible, or to other fixed objects. The
guard shall not create a hazard in itself.
(3) A point of operation guard or device shall be as prescribed in a specific standard,
or, in the absence of a specific standard, shall be designed and constructed, when
required, to prevent the machine operator exposed to the hazard from having any part of
his or her body in the hazardous area during the operating cycle. A guard or device for
the point of operation of a nonproduction arbor press or straightening press is not
required if the machine is equipped with a hand control that is designed to stop the ram
action or return the ram to the up position when released .
(4) Hand tools shall not be substituted for the required guarding or point of operation
devices, except that a hand tool may be used as prescribed in subrule (5) of this rule for a
press brake operation. Where hand tools are used for placing into, and removing material
from, a point of operation, they shall be designed so that the operator is not required to
place a hand within the point of operation.
(5) A bending operation on a press brake involving less than 25 pieces of 1 specific
bend, if not guarded, shall require the use of a hand tool when the operator must hold the
work piece within 4 inches of the point of operation, and a conspicuous sign shall be
posted on the machine stating "Hand tools shall be used to hold stock."
(6) A revolving barrel, container, or drum exposed to contact shall be guarded by a
standard barrier, an enclosure, or equivalent protection where a hazard exists. Access
through a standard barrier or enclosure shall be by a gate equipped with an interlock,
which shall disconnect the power when the gate is opened and require manual
re-actuation of a start button. A constant pressure jog control that bypasses the interlock
may be used to aid loading and unloading.