Short cycle flush valve for commode tanks

Claim 1

In a flush valve for a water storage tank, said tank having an opening through its bottom from which a predetermined volume of water is intended to be discharged to a commode as the consequence of the opening and the re-closing of said flush valve, said flush valve comprising a body including a valve seat with a discharge pipe leading from it, and a valving member having a valve seal adapted to bear against said valve seat to close it, and to be lifted off of it to open the flush valve to flow, said valving member including an inverted cup extending within and beneath the valve seat when the valve seal bears against the valve seat to close the flush valve and having a flexible wall forming a cavity, said wall having a bleed orifice beneath and near the valve seal, and also an opening at its lower end, said opening having a boundary edge, the improvement comprising: a removable rigid tubular insert in said opening, said insert having an enlarged end portion with an orifice therethrough of a size selected to control the rate of entry of water into said cavity to a desired rate, said insert including a neck portion with a peripheral groove adjacent to said enlarged end portion, said boundary edge fitting resiliently in said peripheral groove releasably to hold the insert to the cup with the neck portion extending inside the cup, and a plurality of longitudinal slots through said neck portion extending from a free end of said insert to said groove to enable water to fully drain from the cup to the orifice.