Aircraft door latch lock mechanism

A lift-latch mechanism for an aircraft door for selectively opening, closing, and locking the door in a door opening formed in an aircraft fuselage, said mechanism comprising:

• an opposed set of cam tracks mounted to the fuselage on either side of the door opening;
• a latch shaft assembly including an elongated latch shaft having an axis, said latch shaft extending approximately the width of the door opening and having a pair of opposed ends, at least one mounting member for rotatably securing said latch shaft to the aircraft door and a pair of crank assemblies secured to said opposed ends of said latch shaft to rotate in unison with said latch shaft, wherein each said crank assembly is provided with a cam bearing positioned to be disposed in an adjacent said cam track and said cam bearings having common axes and are axially offset from said latch shaft axis, whereby when said latch shaft is rotated about said latch shaft axis in an opening direction, said latch shaft pivots about said cam tracks so that said latch shaft and the door are moved upwards relative to said cam tracks;
• a handle including a handle shaft, wherein said handle shaft is rotatably attached to the aircraft door along an axis approximately parallel with said latch shaft axis and said handle and said handle shaft can be rotated in a first, opening, direction and in a second, closing, direction opposite said opening direction;
• a lifting cam attached to said handle shaft so as to rotate in unison therewith, wherein said lift cam is formed with a lifting surface;
• a latch shaft lifting assembly including a lifting cam follower having a member positioned to be disposed against and displaced by said lifting cam lifting surface when said handle shaft is rotated in said handle shaft opening direction, and a drive link connected between said lifting cam follower and said latch shaft for rotating said latch shaft in said latch shaft opening direction when said lifting cam follower member is displaced by said lifting cam lifting surface;
• a locking cam attached to said handle shaft to rotate in unison therewith, wherein said locking cam is formed with a locking surface;
• and
• a latch shaft locking assembly including a locking cam follower having a member positioned to abut said locking cam locking surface when said handle shaft is rotated in said closing direction, and a locking link connected between said locking cam follower and said latch shaft is prevent said latch shaft opening direction rotation when said locking cam follower member is disposed against said locking cam locking surface.