Drain construction for a radiator

Claim 1

A drain construction for a radiator which is characterized by: a header for containing a fluid handled by the radiator, said header including a drain area having an inner surface facing into an interior fluid handling portion of said header and an outer surface facing outwardly from said drain area of said header; a first annular pipe extending from said inner facing surface of said drain area of said header to a free end thereof within said interior fluid handling portion of said header, said first annular pipe having an interior axially extending opening of a first fixed diameter extending therethrough from said outer surface of said drain area of said header to said free end of said first annular pipe; a second annular pipe extending from said outer surface of said drain area of said header to a free end thereof above said outer surface of said header, said second annular pipe having an interior axially extending opening of a second fixed diameter extending therethrough from said outer surface of said drain area of said header to said free end of said second annular pipe, said opening of said first annular pipe and said second annular pipe being coaxial with one another with said second fixed diameter of said second annular pipe being larger than said first fixed diameter of said first annular pipe; a third annular pipe intersecting said second annular pipe and providing a passageway from said opening of said second fixed diameter of said second annular pipe to the exterior of said header; a plug received in part in said opening of said first annular pipe and in part in said opening of said second annular pipe, said plug having both a lower portion of circular cross section with a diameter slightly smaller than said first fixed diameter of said first annular pipe and an upper portion of circular cross section with a diameter slightly smaller than said second fixed diameter of said second annular pipe; said lower portion of said plug having a bifurcated section at its free end with each of said bifurcations having a locking foot associated therewith, the length of said lower portion of said plug from said upper portion of said plug to said locking feet of said bifurcations being slightly greater than the length of said first annular pipe from said outer surface of said header to said free end of said first annular pipe whereby said locking feet of said bifurcations are received over said free end of said first annular pipe to hold said plug in place; a circumferential groove formed in an unbifurcated section of said lower portion of said plug; an O-ring of resilient material received in said circumferential groove to provide a fluid tight seal between said unbifurcated section of said lower portion of said plug and said first annular pipe; passageway defining means for forming a passageway through said lower portion and said upper portion of said plug whereby said interior fluid handling portion of said header may be interconnected with said third annular pipe when said portion of said passageway defining means located in said upper portion of said plug is aligned with said passageway of said third annular pipe; a groove formed about an opening formed by said passageway defining means in said upper portion of said plug; sealing means in said groove for providing a fluid tight seal between said opening formed by said passageway defining means in said upper portion of said plug and the surface of second fixed diameter of said second annular pipes; and knob means on said upper portion of said plug for turning said plug between an open position in which said opening formed by said passageway defining means in said upper portion of said plug is aligned with said passageway of said third annular pipe and a closed position where said mentioned elements are not aligned.