7 Mechanical and pneumatic conveyor systems for coffee, cocoa and nuts; machines for the conveying, storing, mixing, cleaning and milling of coffee; sack emptying machines; sieving and cleaning machines for coffee, cocoa and nuts; mixing machines for raw and roasted coffee; destoning machines; air filters and filtering devices for the food industry; coffee skin presses; electromechanical food preparation machines, in particular for processing coffee, cocoa and nuts; power-operated coffee grinders