Steel Drain

Abstract

A drain provides significant advantages over the prior art. A drain fabricated without seams can be easily cleaned and does not provide sites for bacterial growth. The cone and outlet sections of the drain are formed using a spinning process to eliminate the need for welds. The cone section includes a vertical interface lip, such that the outside of the cone section is welded to the rim, eliminating a weld on the interior of the cone. The weld between the rim and the cone section can be polished to eliminate imperfections on the top of the drain. The contour of the cone section also facilitates drainage, and hence reduces bacterial growth, by maintaining a downward slope on a smooth surface. For an embodiment with a membrane flange, dual walls are used such that the membrane flange can be welded to the outer wall of the drain, preventing the welding process from damaging the smoothness of the interior drain wall.

1 . A drain comprises: 
 a seamless interior funnel section formed in a metal spinning process having an interior and exterior surface;    a rim; and    a weld between the rim and the exterior surface of the interior funnel section.    
     
     
         2 . The drain of  claim 1  wherein the interior funnel section has a vertical lip welded to the rim.  
     
     
         3 . The drain of  claim 1  wherein the interior funnel section has a ridge for supporting a grate.  
     
     
         4 . The drain of  claim 1  wherein the ridge has a slope of approximately one to three degrees from a horizontal plane.  
     
     
         5 . The drain of  claim 1  wherein said interior funnel section is stainless steel.  
     
     
         6 . The drain of  claim 1  wherein the rim is stainless steel.  
     
     
         7 . The drain of  claim 1  wherein the weld is polished smooth.  
     
     
         8 . The drain of  claim 1  wherein the rim, weld and interior funnel section are sandblasted.  
     
     
         9 . The drain of  claim 1  and further comprising a grate fabricated using a water jet.  
     
     
         10 . The drain of  claim 1  wherein the rim is fabricated using a water jet.  
     
     
         11 . The drain of  claim 1  and further comprising an exterior funnel section welded to the rim and surrounding the interior funnel section.  
     
     
         12 . The drain of  claim 11  and further comprising a flange welded to the exterior funnel section.  
     
     
         13 . The drain of  claim 12  wherein the exterior funnel section has entry holes formed therein proximate the flange, such that liquid entering the entry holes passes between the interior and exterior funnel sections.  
     
     
         14 . The drain of  claim 13  and further providing a bottom rim welded between the interior and exterior funnel sections with exit holes form therethrough to pass water received through said entry holes.  
     
     
         15 . A method of fabricating a drain, comprising the steps of: 
 forming a seamless interior funnel section using a metal spinning process, the interior funnel section having an interior and exterior surface;    cutting a rim from a metal plate; and    welding the rim to the exterior surface of the interior funnel section.    
     
     
         16 . The method of  claim 15  wherein the welding step comprises the step of welding the rim to a vertical lip of the interior funnel section.  
     
     
         17 . The method of  claim 15  and further comprising the step of polishing a resulting weld between the rim and the interior funnel section.  
     
     
         18 . The method of  claim 15  and further comprising the step of sandblasting the rim, weld and interior funnel section.  
     
     
         19 . The method of  claim 15  and further comprising the step of cutting a grate from a plate of metal using a water jet.  
     
     
         20 . The method of  claim 15  and further comprising the steps of: 
 forming an exterior funnel section; and    welding to the exterior funnel section to the rim such that the exterior funnel section surrounds the interior funnel section.    
     
     
         21 . The method of  claim 20  and further comprising the step of welding a flange to the exterior funnel section.  
     
     
         22 . The method of  claim 21  and further comprising the step of forming entry and exit holes in the exterior funnel, such that liquid entering the entry holes passes between the interior and exterior funnel sections to the exit holes.