passing over the roller and the circular sections 9 10 are sealed by a strip of rubber at the contact surface with the paper web as a result the box 3 in combination with the circumferential periphery of the roller 2 forms a closed chamber into which the coating liquid is charged the box 3 forms an opening to the closed chamber defined by the front edges 4 6 of the blades 4 5 6 7 and the edges 9 10 of the movable end or side pieces of the box this opening is closed by the circumferential periphery of the roller 2 which provides a support member for the paper web 1 which moves across the opening between the blades the coating liquid is pumped into the lower part 11 of the closed chamber to a level 12 the height of the level is adjusted by a spillway 13 which is movable at joint 14 the joint 14 is shown by way of example since the height of the spillway 13 can be adjusted in a number of other ways which are well known as the coating liquid rises to the top of the spillway 13 it flows downwardly to the right of the spillway as viewed in fig1 where it forms a level 17 the liquid is stored in a reservoir 15 and flows into the closed chamber between the spillway 13 and the roller 2 and returns to the reservoir from the space within the box having the level 17 the level 16 within the reservoir 15.