ANTIFILTRATION SCREEN Russian patent published in 2010 - IPC E02B3/16 

FIELD: construction.

SUBSTANCE: antifiltration screen comprises web with drain holes closed with valves, which is arranged between ground protective and underlying layers. Valve comprises flexible pad arranged over drain hole and creating a contact surface onto web plane. Valve is equipped with a cap arranged over flexible pad, body of which is arranged as rigid, and support part is designed with a developed foot and is located beyond border of contact surface. Cap creates a cavity over flexible pad, which hydraulically communicates by means of transit holes to pore space of protective layer, and as valve contact surface is opened by discharge ground water, by means of outlet holes - to drain hole. Cap has a shape of reverse plate, and transit holes are arranged in the form of perforation in body of cap and/or in the form of slots in cap base. Flexible pad, in case it is fully arranged within the cavity limits, is made of more rigid material compared to web material and creates an outlet slot along its perimetre. Flexible pad, in case cap is arranged on it, is made of more elastic material compared to web material and comprises outlet holes. In flexible pad there might be cuts arranged with creation of external tabs, at the same time heads of cuts are arranged in cavity and create outlet holes, and cap is installed on external tabs, thickness and rigidity of which provide for development of transit slots between web and support part foot.

EFFECT: independence of valve operation on thickness of screen protective layer over it.

7 cl, 5 dwg, 2 ex