Patent ID: 7011746

Claim:
A surface drain, comprising a reservatory for water to be drained, the reservatory being connected at a center discharge outlet on the bottom side thereof with a drain outlet pipe and being covered with an upper strainer or grating member downstream of which insert means are arranged within the reservatory for breaking up of air entrapped with the water and for preventing formation of an eddy, wherein said eddy preventing insert means comprise an inner flat grate member which is disposed at a short distance upstream of said center discharge outlet of the reservatory, wherein said reservatory is substantially funnel-shaped towards the interconnecting end of the drain outlet pipe and is provided with a peripheral inner groove for seating the inner flat grate member in a position substantially in parallel and downstream of said upper strainer or grating member whereby a reservoir is formed by the space between the upper strainer or grating member and the inner flat grate member for temporarily collecting the inflow of water before its passage to the drain outlet pipe, wherein said inner flat grate member comprises radially extending circumferentially spaced supporting arms in engagement with the peripheral inner groove of the reservatory, and wherein said inner flat grate member comprises a disk-shaped center portion which is surrounded by a plurality of encircling coaxial grating slots inside of an outer closed annulus over which the radially extending supporting arms project for engagement with the peripheral inner groove of the reservatory.