The idea of a simple machine originated with the Greek philosopher Archimedes, who studied the machines, lever, pulley, and screw, and discovered the principle of mechanical advantage in the lever. Furthermore, the Greek Philosophers defined the classic five simple machines, which were used to roughly calculate the mechanical advantages.
Simultaneous two-handed operation. Where a machine has only one operator, the use of simultaneous two-handed operation buttons can serve as a risk control. This ensures that operation of the hazardous mechanism cannot occur until both hands are clear of the danger area.
People performing tasks, such as maintenance, repair, installation, service and cleaning, are highly vulnerable, and have a higher risk of being killed or maimed through inadvertent operation of machinery and equipment they are working in, on or around.
Workplace health and safety laws require the highest order control be applied. Higher order machinery and equipment risk controls are preventative by nature, are effective and durable for the environment it is used in, and deal directly with the hazard at its source.