Hatch covers

Claim 1

IN A HATCH COVER COMPRISING AT LEAST THREE SECTIONS, THE LATTER BEING JOURNALLED TO EACH OTHER BY MEANS OF HINGES, ONE OF SAID SECTIONS BY MEANS OF A HINGE SHAFT CONNECTED TO THE HATCH COAMING, SAID SECTION, DENOTED THE FIRST SECTION, AND THE SECTION SITUATED CLOSE TO IT AND DENOTED THE SECOND SECTION, ADAPTED TO BE FOLDED UP IN SUCH A WAY THAT THEIR UNDER SIDES BE TURNED TOWARDS EACH OTHER, THE FOLLOWING SECTION, DENOTED THE THIRD SECTION IN OPENED UP POSITION SITUATED WITH ITS UPPER SIDE TURNED TOWARDS THE UPPER SIDE OF SAID SECOND SECTION, AT LEAST ONE SPRING ELEMENT ADAPTED TO BE COMPRESSED AT THE OPENING UP OF SAID FIRST AND SECOND HATCH SECTIONS AND BY ITS SPRING ACTION TO LOWER SAID SECTIONS AT THE CLOSING OF THE HATCH COVER, SAID SPRING ELEMENT BEING ARRANGED ON THE UNDER SIDE OF ONE OF THE TWO SECTIONS SITUATED NEAR SAID HINGE SHAFT AT A DISTANCE FROM THE HINGE BETWEEN SAID FIRST AND SECOND SECTIONS AND ADAPTED NOT TO BE COMPRESSED UNTIL AT THE END OF THE OPENING MOVEMENT OF SAID SECTIONS, SAID HATCH COVER BEING PROVIDED WITH CATCHING MEANS FOR RETAINING SAID FIRST SECTION IN OPENED POSITION AND WITH CATCHING MEANS FOR RETAINING SAID SECOND SECTION AGAINST SAID FIRST SECTION WITH SAID SPRING ELEMENT IN COMPRESSED POSITION, SAID SPRING ELEMENT COMPRISING A FRUSTO-CONICAL HELICAL SPRING INSERTED IN A SPRING HOUSING ON THE UNDER SIDE OF ONE OF SAID TWO LAST MENTIONED SECTIONS, A PISTON ARRANGED ON THE UNDER SIDE OF THE OPPOSITE SECTION, SAID PISTON HAVING ITS FREE END IN ENGAGEMENT WITH AN OPENING IN ONE END OF SAID SPRING HOUSING DURING THE OPENING UP OF THE HATCH COVER WHILE COMPRESSING SAID SPRING.