Chapter 2 Power presses or shear machines
Section 4 Mechanical systems
A clutch of the mechanical press shall have a construction that a main motor cannot be driven when the clutch is in engagement state and the slider stopped but it is unrestricted for having a construction to prevent a body part intervening a hazard zone.
The stroke numbers of a mechanical press with a sliding- pin clutch( hereinafter referred to as the pin clutch mechanical press) or a rolling- key clutch(hereinafter referred to as the key clutch mechanical press) cannot be over that in Attaching table 1.
Materials used in the clutches related to that mechanical press in preceding Article 28 shall have mechanical properties to comply with the national standard in Attaching table 2 or others having equivalent or more.
The heat treatment and surface hardness of those clutches related in Article 28 shall based on the type of the mechanical press and the construction of those to comply with provisions in Attaching table 3.
For those clutches in Article 28 which is pneumatic activating, shall have a spring-release construction or others having equivalent or more safety functions.
The clutch of the pin clutch mechanical press shall have a stopper to stop the crankshaft revolution before a clutch driving cam do not exceed the scope of the clutch slide- pin yet to return back.
The clutch bracket used by the clutch in the preceding paragraph shall have a positioning pin to fix its position.
The clutch-driving cam shall have a construction that it cannot be pressed back if not being acted.
The mounting portion for the clutch-driving cam shall have enough strength to support the impact on the cam.
The clutch of a mechanical press brake shall use a friction-type clutch.
The brake device of the mechanical press with an eccentric mechanism such as a crankshaft(hereinafter referred to as the crankshaft press) shall have a construction that its braking surface cannot be invaded by fat, oil or others but it is unrestricted for the wet-braking type.
The brake device of the crankshaft press that braking is activated with a pneumatic clutch, shall be a spring- fastening type or others having equivalent or more safety function.
The brake device of the crankshaft press except the press mentioned in the preceding paragraph, shall be a non- band braking type but it is unrestricted for a crankshaft press with a capacity less than 100 tons and not a mechanical press brake.
The crankshaft press shall have indicators or others having equivalent function to show the angle of the crank rotation in obvious position.
The stopping angle of the crankshaft for the pin clutch or the key clutch mechanical press shall be within 10 degrees but it is unrestricted for having a construction to prevent a body part intervening a hazard zone.
The above mentioned stopping angle refers to the crank center angle formed by the set stop point and the actual stop point.
The crankshaft press with a crankshaft revolution below 300 revolutions per minute shall have an over running monitor but it is unrestricted for that not needing the protective stop mechanism based on provisions or that having a construction to prevent a body part intevening the hazard zone.
The over running monitor in the preceding paragraph means that can make the protective stop mechanism activated by a directive when the crankshaft cannot be stopped at the set-stop point.
The mechanical press that cluch or brake is controlled by pneumatic or hydraulic shall provide the following solenoid valves:
1. Multi-acting solenoid valves except that having a construction to prevent a body part intervening the hazard zone.
2. Normally closed solenoid valve.
3. Being pressure-return type for the solenoid valve controlled by the pneumatic.
4. Being spring-return type for solenoid valve controlled by the hydraulic.
The mechanical press related to the preceding Article shall have a safety device to prevent the pneumatic or hydraulic pressure for the clutch or brake being over and to make the slider automatically stopped when the pressure below the set.
The mechanical press with a slider adjusting by an electric motor shall have a device to prevent the slider adjusting beyond its upper or lower limits.
The counterbalancer of the slider for the mechanical press shall meet the following provisions:
1. A spring-type counterbalancer : a construction to prevent spring or other parts scattered when it occurs damage.
2. A pneumatic-type counterbalancer:
(1) a construction to prevent piston or other parts scattered when it occurs damage.
(2) a construction that the slider and its accessories shall be held at any position in the stroke when the brake device is not operated, and it can automatically stop the slide acting when the pressure falls below the set.
The positive- clutch mechanical press with a foot control switch or a foot pedal, strokes per minute less than 150, and the capacity below 150 tons, shall have a construction that can prevent a body part intevening the hazard zone or have the protective stop mechanism.
The positive- clutch mechanical press with strokes per minute over than 150 or the capacity over 150 tons shall not be provided the protective stop mechanism.