The two buttons must be pushed at the same time and are located at a distance from each other that prevents simultaneous operation by one hand. The operation should be designed so that if either or both of the buttons are released, the hazardous action of the machinery and/or equipment cannot be reached, or if it can be reached, the mechanism returns to a safe state.
Accidental start-up, or movement of a machine mechanism, can occur: • if control levers or buttons are bumped or knocked • if a short circuit of the control system occurs • when hydraulic or air pressure is released • when undoing retaining bolts. The word machine is derived from the Latin word machina. The modern meaning of the word is influenced due its specialized application in the military siege engines. They are also used in the stage engines, which are used in theater.
A guard can perform several functions including: • denying bodily access • containing ejected parts, tools, off-cuts or swath • preventing emissions escaping • forming part of a safe working platform. Guarding is commonly used with machinery and equipment to prevent access to: • rotating end drums of belt conveyors • moving augers of auger conveyors • rotating shafts • moving parts that do not require regular adjustment • machine transmissions, such as pulley and belt drives, chain drives, exposed drive gears • any dangerous moving parts, machinery and equipment.
People providing maintenance or repair services could: • work alone • work on machinery and equipment at height, or over machinery and equipment to connect services, such as electricity, air or water • access machinery and equipment from the rear or sides • be required to enter confined spaces of larger machinery and equipment • be trapped by the mechanism of the machinery and equipment through poor isolation of energy sources or stored energy, such as spring-loaded or counter-balance mechanisms, compressed air or fluids, or parts held in position by hydraulics or pneumatic (air) rams • move heavy parts when changing the set up of machinery and equipment, or repairing failed parts, such as electric motors or gear box assemblies • disable or remove normal safety systems to access the mechanism of machinery and equipment.
⚙ sewing machine hook timing tool⚙ molding machine