Hatch Lifter-Parts

The 3/8 X 16 pivot bolts were turned down and threaded to take a 1/4 X 20 lock nut after passing through two washers and the thickness of the lifting bars. You could just as easily dispense with this and use a 1/4 X 20 carriage bolt for the whole thing. (I had a lathe so I used it) This basic unit, shown disassembled above and assembled below, is used at each end of the lifter bars.

The lifting bars have rounded ends to match the washers, with a slightly oversized hole at one end and an over width slot at the other. The slot is important for two reasons; first, it allows the hatch to be lifted straight up for the first part of its travel, allowing the hatch to be rabetted in stair-step fashion to keep out water, and secondly, to allow for some imprecision in alignment of the holes drilled for the pivot bolts

Hatch Opening Sequence

A) The hatch in fully closed position.

B) In the first part of the sequence, the hatch lifts straight up to clear any overlap at the hatch perimeter. The pivot bolt slides in the elongated slot at the bottom end of the lifting bar.

C) The hatch swings up and over with the pivot bolts at the top of the lifting bar.

D) The hatch in fully open position.