Patent ID: 8506268

Claim:
Method for accurately dosing a lubricant, wherein a first piston is moved from an initial position relative to a second piston, at the same time enlarging a dosing volume situated between the first and second pistons, and thereby the lubricant is conveyed through an inlet into the dosing volume, subsequently the inlet is sealed and the first and the second pistons with the dosing volume are moved towards a discharge opening until in a discharge position the dosing volume is connected to the discharge opening, then at least one of the first and the second pistons is moved relative to the other of the first and the second pistons, at the same time reducing the dosing volume, and a predetermined dosing quantity of the lubricant is conveyed through the discharge opening, and finally the first and the second pistons are moved back into their initial positions, wherein hydraulic pressure is directly applied to a drive surface on at least one of the first and the second pistons to drive the at least one of the first and second pistons.