R 408.12463
R 408.12463 Point of operation devices.
Cite as Mich. Admin. Code R 408.12463
Rule 2463. (1) Point of operation devices shall protect the operator by 1 of the
following methods:
(a) Preventing or stopping, or both, the normal stroking of a press if the operator's
hands are inadvertently placed in the point of operation.
(b) Withdrawing an operator's hands if they are inadvertently located in the point of
operation as the dies close or preventing the operator from inadvertently reaching into the
point of operation as the dies close.
(c) Preventing the operator from inadvertently reaching into the point of operation at
all times.
(d) Requiring the application of both of the operator's hands to the machine's
operating controls and locating the controls at a distance from the point of operation that
will permit the slide to complete the downward travel or stop before the operator can
reach into the point of operation with his or her hands.
(e) Enclosing the point of operation before a press stroke can be initiated and
maintaining this closed condition until the motion of the slide ceases.
(f) Enclosing the point of operation before a press stroke can be initiated so as to
prevent an operator from reaching into the point of operation before die closure or before
cessation of slide motion during the downward stroke.
(2) A gate or movable barrier device shall protect the operator according to the
following:
(a) A type-A gate or movable barrier device shall protect the operator as prescribed
in subrule (1)(e) of this rule.
(b) A type-B gate or movable barrier device shall protect the operator as prescribed
in subrule (1)(f) of this rule.
(3) The presence-sensing point of operation device shall protect the operator as
provided in subrule (1)(a) of this rule and shall be interlocked into the control circuit to
prevent or stop slide motion if the operator's hand or other body part is within the sensing
field of the device during the down-stroke of the press slide. All of the following
provisions apply to a presence-sensing point of operation device:
(a) The device shall not be used on machines that use full-revolution clutches.
(b) The device shall not be used as a tripping means to initiate slide motion.
(c) The device shall be constructed so that a failure within the system does not
prevent the normal stopping action from being applied to the press when required, but
does prevent the initiation of a successive stroke until the failure is corrected. The failure
shall be indicated by the system.
(d) Bypassing the protection function of a presence-sensing device during the
upstroke of the press slide is permitted for the purpose of parts ejection, circuit checking,
and feeding.
(e) The safety distance (Ds) from the sensing field to the point of operation shall be
greater than the distance that is determined by the following formula:
D(s)
=
63 inches/second X T(s)
where:
D(s)
=
minimum safety distance (inches); 63 inches/second =
hand speed constant;
and
T(s)
=
stopping time of the press measured at approximately 90 deg.
position of crankshaft rotation (seconds).
(f) Guards shall be used to protect all areas of entry to the point of operation that are
not protected by the presence-sensing device.
(4) The pull-out device shall protect the operator as prescribed in subrule (1)(b) of
this rule and shall include attachments for each of the operator's hands. All of the
following provisions apply to a pull-out device:
(a) Attachments shall be connected to, and operated only by, the press slide or upper
die.
(b) Attachments shall be adjusted to prevent the operator from reaching into the
point of operation or to withdraw the operator's hands from the point of operation or other
pinch points before the dies close.
(c) A separate pull-out device or other safeguarding device that is in compliance
with the provisions of this standard shall be provided for each operator if more than 1
operator is used on a press.
(d) Each pull-out device in use shall be visually inspected and checked for proper
adjustment at the start of each operator's shift, after a new die setup, or when operators
are changed. Necessary maintenance or repair, or both, shall be performed and completed
before the press is returned to production. The employer shall maintain records of these
inspections and the maintenance work performed.
(e) Bolts, locator pins, or any other projections shall not be located in a manner that
would catch the pullback cable or wristlet and hold an operator's hand in a pinch point or
the point of operation.
(5) A sweep device shall not be used for point of operation safeguarding on a
mechanical power press.
(6) A holdout or a restraint device shall protect the operator as prescribed in subrule
(1)(c) of this rule and shall include attachments for each of the operator's hands. These
attachments shall be securely anchored and adjusted so that the operator is restrained
from reaching into the point of operation. A separate set of restraints or other
safeguarding device that is in compliance with the provisions of this standard shall be
provided for each operator if more than 1 operator is required on a press.
(7) The 2-hand control device shall protect the operator as prescribed in subrule
(1)(d) of this rule. All of the following provisions apply to a 2-hand control device:
(a) When used in press operations requiring more than 1 operator, separate 2-hand
controls shall be provided for each operator and shall be designed to require concurrent
applications of all operator's controls to activate the slide. The removal of a hand from
any control button shall cause the slide to stop.
(b) Each 2-hand control that is used as a point of operation device shall be operated
in the single-stroke mode only.
(c) When hand-in-die loading or unloading is used, the safety distance (Ds) between
each 2-hand control device and the point of operation shall be greater than the distance
determined by the formula prescribed in subrule (3)(e) of this rule.
(d) The position of the 2-hand controls shall be established and fixed in accordance
with the provisions of subrule (1)(d) of this rule or subdivision (c) of this subrule,
whichever shall apply. Only the supervisor or safety engineer may authorize relocating
the controls.
(8) The 2-hand trip device shall protect the operator as prescribed in subrule (1)(d)
of this rule. The device shall conform as follows:
(a) When used in press operations that require more than 1 operator, separate 2-hand
trips shall be provided for each operator and shall be designed to require concurrent
application of all operator's controls to activate the slide.
(b) Each 2-hand trip shall meet the construction requirements of R 408.12434.
(c) The safety distance (D(m)) between the 2-hand trip and the point of operation
shall be greater than the distance determined by the following formula:
D(m)
=
63 inches/second X T(m);
where:
D(m)
=
minimum safety distance (inches); 63 inches/second=hand
speed constant;
And
T(m)
=
the maximum time the press takes for the die closure after it has
been tripped (seconds). For full revolution clutch presses with
only one engaging point T(m) is equal to the time necessary for
one and one-half revolutions of the crankshaft. For full
revolution clutch presses with more than one engaging point,
T(m) shall be calculated as follows:
T(m)
=
[1/2 + (1 divided by number of engaging points per revolution)]
X time necessary to complete one revolution of the crankshaft
(seconds).
(d) Two-hand trips shall be established and fixed and only a supervisor or safety
engineer may authorize their relocation.