Rule 4123:1-13-02 | Mills.
(A) Mill roll height.
All mills shall be installed so that the top of the operating rolls is no less than fifty inches (one hundred twenty-seven centimeters) above the level on which the operator stands, irrespective of the size of the mill. This distance shall apply to the actual working level, whether the actual working level be at the general floor level, in a pit, or on a platform.
(B) Mill controls.
(1) Safety trip control.
A safety trip control shall be provided in front and in back of each mill to stop the mill when it is tripped. The safety trip control shall be accessible and operate readily on contact. The safety trip control shall be one of the following types or a combination thereof.
(a) Pressure-sensitive body bars.
Installed at front and back of each mill twenty inches (50.8 centimeters) horizontally from the crown face of the roll. Pressure-sensitive body bars shall operate readily by pressure of the mill operator's body and be installed on new equipment.
(b) Safety trip rod.
Installed in the front and in the back of each mill and located within two inches (5.1 centimeters) of a vertical plane tangent to the front and rear rolls. The trip rods shall be within easy reach of the operator but no more than seventy-two inches (182.9 centimeters) above the level on which the operator stands. The trip rods shall be accessible and operate readily whether the rods are pushed or pulled.
(c) Safety trip wire cable or wire center cord.
Installed at the front and back of each mill and located within two inches (5.1 centimeters) of a vertical plane tangent to the front and rear rolls. The cables shall be within easy reach of the operator but no more than seventy-two inches (182.9 centimeters) above the level on which the operator stands. The trip wire cable or wire center cord shall operate readily whether cable or cord is pushed or pulled.
(d) Fixed guards.
A fixed bar across the front and one across the back of the mill approximately forty inches (101.6 centimeters) vertically above the working level and twenty inches (50.8 centimeters) horizontally from the crown face of the roll should be used. A safety trip method as described in paragraph (B)(1)(a), (B)(1)(b), or (B)(1)(c) of this rule shall be used with a fixed bar.
(2) Other equipment.
All other equipment, such as a mill divider, support bars, spray pipes, feed conveyors, or strip knives, shall be located in such a manner as to avoid interference with access to or operation of safety devices.
(C) Protection by location.
Where a mill is so installed with fixed parts that persons cannot normally reach through, over, under, or around any element to come in contact with the roll bite or be caught between a roll and an adjacent object, safety control devices listed in paragraph (B) of this rule shall not apply.
(D) Trip and emergency switches.
All trip and emergency switches shall not be of the automatically resetting type but require manual resetting.
(E) Emergency stopping limits.
(1) Determination of distance of travel.
All measurements on mills shall be taken with the rolls running empty at maximum operating speed. Stopping distances shall be expressed in inches or centimeters of surface travel of the roll from the instant the emergency stopping device is actuated.
(2) When tripped by the emergency stopping device all mills, irrespective of the size of the rolls or their arrangement, individually or group-driven, shall stop within a distance, as measured in inches or centimeters of surface travel, no greater than one and one-half per cent of the peripheral no-load surface speeds of the respective rolls as determined in feet per minute or centimeters per minute. See "Fig. 1".
Last updated February 3, 2025 at 8:37 AM
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