Patent ID: 7621741

Claim:
A safety door for temporarily covering a manhole formed in a rotary kiln by removing a door which is secured to said rotary kiln during normal operation but is removed only during kiln maintenance operations said safety door being secured to said kiln only during said maintenance operations, said safety door comprising; (a) a hollow cylindrical rotary kiln having an interior and an exterior surface and a diameter large enough for an adult person to stand up inside the kiln; (b) a plurality of members extending outwardly from the exterior surface of said cylindrical rotary kiln and on opposite sides of said manhole; (c) a frame having first, second, third and fourth sides; (d) means for attaching said frame to the members extending outwardly from the exterior surface of said cylindrical rotary kiln and on opposite sides of said manhole; (e) a hatch; (f) means for pivotally securing said hatch to said frame; and (g) means for continuously biasing said hatch toward said kiln exterior surface with a force sufficient to support approximately four hundred pounds placed on said hatch.