Coex

CoEx is the name of a brewer in a espresso machine, coffee machine or vending machine which is able to brew a cup of coffee as well as an espresso. It is a mechanism in which with ground coffee and hot water (on pressure in case of espresso), a cup of coffee or espresso can be made, and from which, after the drink has been prepared the coffee residue is removed.

The mechanism

Firstly ground coffee is dosed into the cylinder chamber. Then the cylinder chamber is closed by the upper piston, which moves above the chamber then down to seal it. Hot water is passed through under pressure, coming from the back of the mechanism via the lower piston, through the ground coffee in the cylinder chamber. The brewed coffee (or espresso) leaves the system through a filterscreen in the upper piston, at the front of the system. After brewing the upper piston is pulled out of the cylinder and moved to one side. The lower piston then moves upwards, pushing the coffee residue out of the cylinder chamber. In the last phase the coffee residue is wiped from the brewer toward a waste bucket next to the brewer and the mechanism returns to its start position.

Coffee or espresso