oriented pump having a push - member - distributor axially and angularly movable including at least one lug cooperative with a blocking ramp having an indexed abutment for preventing and allowing at will the depression of the push - member and the disengagement of the push - member from bearing on the head of the piston . the seal is maintained between the push - member and the rod of the piston in all positions and the push - member is axially retained independently of the piston . the push - member is oriented on the neck of a given container at will when assembling the pump .