Patent ID: 8851790

Claim:
A hatch, comprising; a cover plate having a plurality of fasteners around a perimeter thereof, the fasteners having a threaded end that engages threads in a base that is located within a rectangular channel frame to apply an adjustable compressive force on the cover plate; a compressible material affixed to the cover plate inward from the perimeter adjacent to the fasteners; a first vertical portion having a first end penetrating the compressive material to form a water barrier wherein a penetration distance is determined by the compressive force, wherein the first vertical portion is one side of the rectangular channel frame, the rectangular channel frame having an opposing second vertical portion, a first horizontal member connecting a second end of the first vertical portion to a first end of the second vertical portion and a second horizontal member extending from a second end of the second vertical member to a location separated from the perimeter of the cover plate by a gap; and a mechanical stop that determines a maximum penetration depth of from 15% to 35%, in length, of a thickness of the compressible material, wherein the mechanical stop is disposed on a top surface of the base and has a height effective to contact a bottom surface of the cover plate when the maximum penetration depth is obtained.