Mechanisms for respectively opening and closing and locking hatch cover sections of the kind in question on board ships customarily consist of hydraulically actuated piston cylinder jacks or hydraulic motors and chains. The aforementioned hatch cover sections are caused in this way to be displaced on wheels to the desired positions along tracks intended for the purpose.

Previously disclosed solutions for effecting the actual opening and closing and locking of the hatch cover sections comprise pivoting link arms which are connected together and actuated by a common jack in such a way, with the help of gripping devices, as to cause the hatch cover sections to be displaced respectively in a direction away from one another and in a direction towards one another for the purpose of opening and closing access to a lockable cargo space of the kind in question on board. A separate locking arrangement needs to be provided in this case.

Also previously disclosed through WO 02/090175 Al, for example, is a mechanism for actuating hatch cover sections on board a ship. Pairs of gear segments are utilized for this purpose, which are capable of being actuated by a jack causing them to pivot to intended positions. A special locking

arrangement is required, however, in order to retain the hatch cover sections in place in the closed position, although the aforementioned locking arrangement is connected in such a way as to act between the jack and the gear segment.

Previously disclosed solutions require complicated manufacturing of constituent parts and do not permit simple installation as a common unit which does not need to be specially adapted between the deck and the frame in order for the mechanism to function reliably.

The principal object of the present invention is thus, in the first instance, to solve the aforementioned problems, among others, in a simple and effective fashion.

The aforementioned object is achieved by means of an arrangement in accordance with the present invention, which is characterized essentially in that pairs of pivoting link arms, which are mounted on a common part of the ship, are each attached at their respective one end, preferably via claw connections, to a corresponding hatch cover section, and are attached at their respective other end to a divided link connection that is capable of being influenced by force by an aforementioned jack, and in that both link arms are attached to one another by means of a distance piece, whereby the application of force by means of the jack causes the link arms, by the forced interaction of the link connection parts, to pivot from the lowered and retracted locked position to the open position, in which position the respective attached hatch cover section is retained in the raised and parted position.

The invention is described below as a number of preferred illustrative embodiments, in conjunction with which reference is made to the accompanying drawings, in which:

Figures 1 and 1A show the arrangement with its associated mechanism with associated hatch cover sections held in the open position viewed respectively from the side and directly from above; Figures 2 and 2A show the mechanism in the open position with hatch cover sections held in the parted position at a distance from one another and viewed in perspective and from one end ; Figures 3-3C show the mechanism in the closed and locked position with the hatch cover sections held together and viewed both in perspective from one end and from the side, and directly from above; and Figure 4 shows the function of the locking mechanism in detail in order to achieve self-locking.

The function of this mechanism is to lift/operate and lower/operate the two hatch cover sections respectively from the closed to the open position and vice versa, when the hatch cover sections are simultaneously battened down and locked in their closed position. This new solution is a further development of previously disclosed solutions. Its characteristics compared with previously disclosed solutions are: the links are equivalent to the gear segments, although they require simpler manufacturing. The mechanism consists of a number of links and involves a saving in weight compared with gear rack segments.

The entire mechanism can be built and installed as a unit without the need for adaptation between the deck and the frame.

An arrangement 1 for a mechanism 2 for effecting the actuation of the movable hatch cover sections 3,4 of a ship respectively between the closed position A and the open position B and between the open position B and the closed position A, which also comprises pivoting link elements 5,6 movably attached

to the respective hatch cover sections 3,4 that are capable of being influenced by force by means of an actuating cylinder hydraulic jack 7, exhibits pivoting link arms 8,9 capable of interacting in pairs. Quite small parts of the respective intended hatch cover sections 3,4 are illustrated only schematically in the drawings, because such hatch cover sections normally cover the entire cargo width and longitudinal extent of the ship. The aforementioned link arms 8,9 are supported on a common part 10 of the ship and are each attached at their respective one end 8A, 9A to their corresponding hatch cover section 3,4, preferably via so-called claw connections. The link arms 8,9 are attached at their respective other end 8B, 9B to a divided link connection 11. The aforementioned link connection 11 is influenced by force FF, FB by an aforementioned jack 7.

Both link arms 8,9 are also attached to one another by means of a distance piece 12. The link arms 8,9 are caused to pivot in this way, when force is applied by means of the jack 7, by the forced interaction of the link connection parts 13,14, from the lowered and retracted locked position C to the open position D. In the aforementioned open position, the respective attached hatch cover section 3,4 is retained in the raised and parted position B.

The aforementioned divided link connections 11 are formed, as shown in the drawings, by pairs of interacting articulated arms 13,14, which are attached to one another in an articulated fashion at their respective one end 13A, 14A via a common articulation 15. At a distance from the aforementioned common articulation 15, each of the two articulated arms 13,14 is attached in an articulated fashion to its corresponding link arm 5,6 via articulations 16,17.

The aforementioned common articulation 15 is so arranged as to be capable of passing an imaginary straight line 18, which runs between the articulations 16,17 belonging to the respective link arm 8,9, at a given angle X in order to achieve so-called over-centre locking of the two links 8,9 in conjunction with passing the aforementioned imaginary line 18 and in order to permit the release of the locking in conjunction with the return of the aforementioned common articulation 15 past the aforementioned imaginary line 18.

Both of the respective link arms 8, 9 are pivotally mounted via articulations 19,31 and are supported by a common supporting part 10 on the ship. An aforementioned supporting part 10 is preferably formed by an elongated beam and/or plate 23, by which the mechanism 2 is supported as a unit 24, which can easily be transported and securely mounted rapidly and simply on the deck of the ship on the frame 21 of the opening alongside its frame top 22 without the need for complicated operations.

One articulated arm 13 exhibits an angled pivot arm 25, which is directly or indirectly attached to an aforementioned jack 7. The aforementioned angled pivot arm 25 is so arranged as to extend at an obtuse angle Z from the remaining part 20 of the associated articulated arm 13, preferably between 100° and 140°.

The articulation 16 between the aforementioned articulated arm 13 and one of the link arms 8 is situated for this purpose in the area of both pivot arms 20,25 of the aforementioned articulated arm 13, whereby the desired locking and unlocking of the mechanism 2 can be effected simply by respectively retracting and extending the jack 7.

The two link arms 8,9 are also attached to one another via a rigid arm 12, which functions as a distance piece and is

attached in an articulated fashion to fixing lugs 27,28 on the respective link arm 8,9 at its respective one end 8B, 9A, as illustrated by way of example in Fig. 4.

The link arms 8,9 preferably exhibit triangular form with the articulations 29,30 ; 16,17 for the hatch cover sections 3,4 and the articulated arm 13 situated at its respective extremities.

As can be clearly appreciated from the perspective views in Figs. 2 and 3, the link attachment parts 13,14 are double, with a pair of links each situated on its own side I, II of the two link arms 8,9.

In order to permit simple installation of the mechanism, the aforementioned mechanism 2 is constructed as a common unit which is so arranged as to be capable of being installed in the position intended for its use simply by being attached to the ship by means of welding and/or bolted joints. The aforementioned jack 7 is supported by the aforementioned unit 24 and is pivotally attached at its one end 7A to a pivot 32 that is supported by the aforementioned plate 23 and/or beam 10 and is pivotally attached at its other opposing end 7B to a pivot 26.

The invention is naturally not restricted to the embodiments described above and illustrated in the accompanying drawings. Modifications are possible, in particular with regard to the nature of the various parts, or by the use of equivalent technology, but without departing from the area of protection afforded to the invention, as defined in the Patent Claims.