Tide gate valve

Claim 1

An inversion-resistant tide gate valve for large-sized sewage conduits, particularly storm sewer pipes having diameters on the order of 36", 72" and greater, comprising: (a) a valve body having a flow-through passage for sewage fluids; (b) a flexible, resilient sleeve elongated along an axis of symmetry and mountable in the valve body in co-axial relationship with the passage, said sleeve having an upstream fluid inlet end region in constant fluid communication with the passage, a downstream fluid outlet end region, and a tapered intermediate region between the inlet and outlet regions, (i) said tapered region having a plurality of pairs of converging sides circumferentially arranged about the symmetry axis, each pair of converging sides having two side walls which meet at and extend along an inclined crease line that converges at an angle of about 38° relative to the symmetry axis at a a point thereon, (ii) said downsteam end region having a pair of opposed lips at each junction between the pairs of converging sides, each pair of lips extending in the axial direction from said point of convergence to a downstream end face on the downstream end region, each pair of lips having lateral outer edges which extend along the symmetry axis, all of the lateral outer edges being continuously joined and bounding a fluid-impervious extension of the tapered region, each pair of lips also having lateral inner edges which are unconnected and discrete and are movable away from each other in response to a pressure head exerted along the downstream direction; and (c) means for resisting inversion of the sleeve in response to a back-pressure force exerted along the upstream direction, said inversion-resisting means including a plurality of axially-extending reinforcing elements embedded in the sleeve at each pair of opposed lips between the inner and outer edges thereof, the number of reinforcing elements corresponding to the number of pairs of lips, each reinforcing element extending along the respective pair of lips along the upstream, tapered and downstream regions to the downstream end face of the latter.