Siphonic yard gulley for draining paved surfaces - has demountable bell forming seal and fixed by bayonet or screw thread connectors

摘要

The syphonic yard gulley may be used to drain surface water from paved areas or roofs. It includes a demountable bell(6) to form the syphon, and has a mechanical connection between the bell and the gulley pot. The connection may be of the bayonet type, may use screw threads, or may incorporate a rotatable key. The gulley comprises a flat-bottomed pot(1) with an outlet pipe(2) projecting vertically down from the centre of the base. The pipe also extends upwards to form an annular syphon channel(5) and a spigot(3) which locates the bell. The lip of the spigot may include 'L' shaped grooves(11) at intervals on the perimeter. The interior of the bell(6) may include part radial webs(8) with a stop surface(10) and lugs(7) to form the bayonet connection.