Inversion-resistant, readily-openable tide gate valve

Claim 1

An inversion-resistant tide gate valve for sewage conduits, particular for large-sized storm sewer pipes, comprising: (a) a sleeve bounding a longitudinally-extending flow-through passage for sewage fluids, (b) said sleeve having an upstream fluid inlet end region mountable on a discharge end of a sewage conduit which is elongated along an axis of symmetry, (c) said sleeve having a downstream fluid outlet end region which has an upper lip and a lower lip opposed to each other and symmetrically arranged relative to the axis, said lips being movable from a closed position in which the lips sealingly engage each other, to an open position in which the lips are located apart from each other in response to a pressure head within the passage and exerted in a direction downstream of the passage, (d) said sleeve having a tapered intermediate region which has an upper wall and a lower wall symmetrically arranged relative to the axis, said upper and lower walls respectively merging, and being jointly movable, with the upper and lower lips, (e) said sleeve being constituted, at least in part, of a flexible material, (f) a plurality of pads arranged along the upper and lower walls and lips of the sleeve, said pads being constituted of a material less flexible than the flexible material of the sleeve for imparting strength to the sleeve to prevent the sleeve from sagging and to prevent the lips from inverting in response to a back pressure exerted in a direction upstream of the passage, said pads being spaced apart from each other to bound therebetween flexible hinge regions at which the upper and lower walls and lips are bendable for imparting flexibility to the sleeve to enable the lips to readily move from the closed to the open position in response to the pressure head, first ones of the pads on the upper lip being staggered relative to second ones of the pads on the lower lip, third ones of the pads on the upper wall being symmetrically arranged relative to the axis with respect to fourth ones of the pads on the lower wall, said first, second, third and fourth ones of the pads being embedded in the flexible material of the sleeve, and an additional longitudinally-extending annular pad on the upstream fluid inlet end region for imparting additional strength to the sleeve to resist sagging of the same.