Closing means for a hatch cover

Claim 1

Cover means for a hatch opening comprising: a hatch cover; hinge means providing for pivotal opening and closing movement of said hatch cover; a locking strap having lip means overlapping and extending beyond the hatch cover and said locking strap having means attached to said hinge means; retainer means for attachment to the lip means of said strap for securing the strap in a locked position; a rotatable hand wheel; a threaded shaft with means attached to said hand wheel for rotation of said shaft; said locking strap having a top, an underside, and an opening for passage of said shaft; said hatch cover having a hub with a chamber therein; said chamber including closed sides, a closed lower end formed by a removable end cover piece and a threaded open upper end formed by an internally threaded means; said hub having a shoulder; said internally threaded means having means mounted upon said shoulder for securely holding the internally threaded means within said chamber; means attaching the internally threaded means to said shoulder; said shaft having threaded means extending through the internally threaded means for movement of the shaft into and from the chamber when the shaft is rotated; said rotatable hand wheel having means adjacent the top side of said locking strap and engageable therewith for urging the locking strap downwardly; thrust means attached to said shaft adjacent the underside of said locking strap and opposite the hand wheel for urging the locking strap upwardly; and, said thrust means and said internally threaded means being spaced apart a first distance when in the locked position and said first distance increasing to a greater distance upon rotation of the hand wheel in one direction whereby the thrust means engages the underside of the locking strap forcing apart the internally threaded means and thrust means to urge the hatch cover down to close off said hatch opening.