A water aerator having a rubber plate with fine slots clamped at its edges to a rigid circular plate by a screw ring

摘要

The aerator has a rigid circular retaining plate 1 made of plastic with a slotted resilient rubber plate 5 clamped to it by a screw ring 13. In use the aerator is supported by an air pipe 2 that is connected to the centre of the circular retaining plate so that pressurised air can be introduced between the rubber plate and a flat surface 4 of the retaining plate, the spacing between the rubber plate and the flat surface being adjustable by a screw movement of the ring 13. The rubber plate has a plurality of fine slots (7, Figure 2) which open and release fine air bubbles into the water when air is supplied from the connection pipe or close when no air is supplied to prevent water from entering the pipe. The edge of the retaining plate is divided by a step 12 into an upper portion 8 with a cylindrical surface 9 and a lower portion 10 with a screw thread 11. The screw ring has a threaded portion 14 associated with thread 11, a cylindrical internal face 15 and an inwardly orientated rib 16 encircling the ring. The edge of the rubber plate lies on the surface 9 and extends into a thickened bead 17 which abuts against the face 15 being disposed beneath the rib 16. By screwing the ring on to the retaining plate the thickened bead is gripped and drawn downwardly thereby tensioning the rubber plate and producing an airtight seal between the bead and the surface 9.