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.
Where exposure to machinery and equipment hazards cannot be eliminated or substituted for machinery and equipment of improved design, risk controls must be applied to the hazards to prevent or reduce the risk (chance) of injury or harm.
Where frequent cleaning is required, the guard may be constructed of mesh that prevents intrusion of body parts, but allows for hosing. Food production workplaces, that use conveyors in areas where hygiene or food safety is an integral part of the operation, use fixed mesh guarding of conveyor end rollers.
Equipments basically serve as tools, essential for the mechanical needs, to repair a machine. They are the most important items that have enabled the ancient humans to climb to the top of the food chain. They are things which help in the acquirement of any desired substance.