Roof drain coupling

Abstract From the Canadian patent

A drain assembly is disclosed having a drain insert member with a tube portion carrying at its upper end a flange which extends radially outwardly. A clamp ring member is adapted to overlie and be clamped onto the flange member. The flange has a plurality of post members which extend upwardly from the upper surface of the flange. The clamp ring member has a plurality of upwardly extending socket forming members each defining a socket recess open at a lower surface of the clamp ring member and adapted to receive a post member in the socket recess therein. A screw member extends downwardly through the top of the socket forming member to engage the post member and draw the clamp ring member …