RACLETTE POUR UNE MACHINE DE SERIGRAPHIE A ECRAN PLAT

A doctor for a flat screen printing machine, shaped as an elongated vessel with variable cross-section along its length, is symmetrical to the vertical axis Z. The height of the vessel is greatest at the point of the Z axis, where there are attached to it a flexible hose for supply of printing paste and a flexible hose for air draw-off. The cross-section of the doctor is an isosceles trapezium, turned with its smaller base towards the flat screen. On this base there is fastened a T-shaped lug onto which there is mounted a U-shaped applying profile made of friction material. In the center of the small base of the trapezium, the T-shaped lug and the U-shaped applying profile there is shaped along the length of the vessel a metering slot. At the metering slot there is disposed a valve mechanism which consists of a T-shaped section having a length greater than that of the metering slot, and to the vertical arm of this section there are attached hingedly the piston rods of two pneumatic cylinders, which are symmetrically disposed to the Z axis. The horizontal arm of the T-shaped section is directed towards the metering slot and is provided with a seal.