#mechanical device

• Countersink — A mechanical device, machinery, or tool mounted on a machine tool (such as a drill press or milling machine), used for widening, deepening, or calibrating holes previously executed in metal, wood, or plastic. As an adjective, it describes any factor, substance, mechanism, or instrument fulfilling the structural function of increasing depth.
• Aerator — A device, apparatus, or mechanical installation used to introduce air or oxygen into a liquid, solid medium, or enclosed space. In aquaristics, it represents the pump that dissolves oxygen in water; in plumbing, it is the tap nozzle that mixes water with air to reduce consumption; in agriculture, it is the machine that perforates the soil to loosen it.
• Sharpener — A skilled worker whose occupation is sharpening tools, blades, or cutting instruments in a workshop; as a neuter noun, it represents a manual, mechanical, or electrical device used for tapering and finishing pencil tips or for rectifying the edge of knives and other metal pieces.
• Autoloader — An electromechanical device, heavy machinery unit, industrial vehicle, or complex digital module designed to perform loading operations in a fully automated manner. In logisitics and civil construction, it defines self-propelled vehicles equipped with buckets or hydraulic arms used for moving bulk materials, whereas in advanced military engineering, it represents the robotic mechanism that replaces human loaders by rapidly feeding projectiles and propellant charges into a cannon.