Bulkhead door locking

Abstract

An apparatus and method is disclosed for selectively locking and unlocking a large, heavy bulkhead door at several points about its periphery. A plurality of locking fingers are slidably mounted on the door for selective extension and retraction with respect to the door edges. A handle mounted on the door provided for rotational movement of a handle shaft. A double rack and pinion linkage responds to rotational movement of the handle shaft to cause a pair of drive rods to move axially and linearly outwardly and inwardly from the handle shaft. A pair of shaft drive assemblies, including second rack and pinion structures, causes axial rotation of two substantially vertical drive shafts extending along the door edges. A plurality of finger drive assemblies is coupled, by third rack and pinion structures, to extend and retract the locking fingers in unison in response to rotation of the drive shafts. The door itself is suspended on a plurality of special lost motion floating hinges to enable it to seat evenly in a casing defining the opening the door is to cover, in order to establish a uniform seal force about the periphery of the door and the inside edge of the casing. The locking fingers each have an inclined portion to facilitate a ramped engagement with the casing to increase the sealing force as the fingers are progressively extended. A detent structure associated with each finger holds the fingers in locked position until release and door opening is desired. A silver-impregnated elastomeric resilient door sealing member is provided.