Conventionally, the load/unload hatchway to the ship's cargo space is closed at least for the duration of the overseas passage with a hatch cover typically comprising two or a greater number, e. g., four hatch sections. The hatch sections are generally connected to each other pivotally by a hinge and protected by seals at the hatch section edges to achieve at least pro- tection from bad weather. In the closed position of the hatch cover, the sections of the hatch cover are aligned essentially horizontal and adjacent to each other so as to cover the entire opening of the hatchway. Hatch covers of four or more hatch sections are generally equipped with two separate actuators of which the first one rotates upright the two first hatch sections closest to the first actuator, whereby the two last sections are simultaneously guidedly pulled toward the hatchway edge that is equipped with the actuator, whereby the next to last hatch section reaches the rotating mechanism. Then, the rotating mechanism is driven by means of the second actuator that rotates the two last hatch sections into an upright position side by side with the other, previously stowed sections. In the fully open position of the hatch cover, the hatchway is entirely free for cargo unloading or loading. By way of example, this description was given in singular pertaining to a first actuator, a rotating mechanism and its actuator.

In practice, however, such an arrangement is located to both sides of the hatchway.

In embodiments of the above-described type, the rotating mechanism and its actuator are conventionally placed close to the exterior edge of the hatchway coaming. In practical operating situations, however, problems are encountered particularly in regard to equipment layout inasmuch the free space remaining between the hatchway coaming and the walkway at the ship's side is rather narrow, and particularly, because the ship is often narrowed at this area and an obstacle such as a crane pillar, container support pillar or a rotatable accommodation ladder is typically situated in this area. To fit a hatch cover rotating mechanism in this space, the area about the coaming must be widened which is only possible by making the hatchway narrower, the ship wider or reducing the size of equipment placed on said area.

It is an object of the present invention to provide a rotating mechanism capable of overcoming the above-described problems. The rotating mechan- ism according to the invention is characterized in that the rotating mechan- ism is placed differently from prior-art embodiments at the fore/aft end of the hatchway coaming, in the transverse and longitudinal directions of the ship at least partially inside the hatchway coaming of the cargo space, whereby the pivot and actuator means of the rotating mechanism are placed outside the hatchway coaming so as to leave the cover block lifting end of the rotating mechanism under the hatch cover, either located in the cargo space or situated in the interior space of the hatch cover structure. Hence, the rotating mechanism requires no footprint from the area between the hatchway coaming and the ship's side rail, which is a significant benefit over conventional arrangements. The invention also offers an essential im- provement in occupational safety inasmuch the rotating mechanism is located away from walkways. One further benefit of the invention is that the arrangement does not steal any valable cargo space.

A preferred embodiment of the invention is characterized in that a notch is made to the end edge of the hatch section or alternatively, to the coaming of the cargo hatchway suitable for accommodating the rotating mechanism, thus assuring the tightness of a closed hatch cover against bad weather.

Another preferred embodiment of the invention is characterized in that the actuator means of the rotating mechanism are adapted close to the exterior edge of the hatchway coaming to gain protection from damage by cargo loading/unloading and easier accessibility to servicing.

In the following, the invention is examined in greater detail with the help of a preferred exemplifying embodiment by making reference to the appended drawings, in which: Figure 1 shows a schematic side view of a four-section hatch cover in its closed position; Figure 2 shows the same view as in Fig. 1, now having the first hatch section pair closest to the hatchway end stowed in its upright position by means of a first actuator; Figure 3 shows the same view as in Figs. 1 and 2, now having the trailing hatch section pair stowed in its upright position by the rotating mechanism driven by its actuator; Figure 4 shows a top view of a portion of the hatchway and its coaming as seen from the direction of lines A-A of Fig. 1, whereby the rotating mechanism with its actuator are readily visible; and Figure 5 shows a sectional view of diagram of Fig. 4 taken on line B-B.

Referring to Fig. 1, therein is shown a side view of a hatch cover in its closed position, said hatch cover comprising four hingedly to each other connected hatch sections 1,2,3 and 4. In the closed position shown in Fig. 1, the hatch cover closes in a conventional manner the entire hatchway opening of a cargo space 5 when the sections 1-4 are placed in a substan- tially horizontal position. To section 1 is connected a first actuator 6 having its other end connected to a rigid structure of the ship. Additionally, the operating equipment of the hatch cover comprises a rotating mechanism 7 shown dark hatched in the diagrams and its actuator 8. The actuators 6 and 8 can be hydraulic cylinders, for instance.

The rotating mechanism is conventionally implemented using a lever with a short and long arm that is pivotally mounted at the joint of the arms to a rigid structure of the ship. One end of the actuator 8 of the rotating mech- anism 7 is connected to the short arm of the rotating mechanism, while the other end of the actuator is connected to the ship's rigid structures. As can be seen from Fig. 4, the novel rotating mechanism 7 is placed differently from prior-art embodiments at the end of the hatchway coaming, in the transverse and longitudinal directions of the ship at least partially inside the hatchway coaming of the cargo space 5, whereby the pivot and actuator means 8 of the rotating mechanism 7 are placed outside the hatchway coaming so that the hatch section lifting end of the rotating mechanism 7 remains in the hatchway under the hatch cover, either located in the cargo space 5 or situated in the interior space of the hatch cover structure. In Fig. 4, the edge of the hatchway coaming is denoted by reference numeral 10 and the ships side rail with reference numeral 9. A portion of the rotating mechanism 7 and its actuator 8 are advantageously located outside the hatchway coaming of the cargo space 5.

In Fig. 5 is shown a sectional view taken along line B-B of Fig. 4. As can be seen therefrom, to the edge rail 11 of the hatch section 1 is made an essen-

tially trapezoidal notch 12 to accommodate the rotating mechanism 7.

Reference numeral 13 denotes the hatchway coaming on which the section 1 is placed partially resting thereon. Reference numeral 14 denotes the additionally required seals between the arm and the hatch cover and between the arm and the hatchway coaming. Alternatively, the notch can be made to the hatchway coaming 13.

Opening the hatch cover from its position 1 takes place in basically con- ventional manner. In the beginning, the first actuator 6 rotates the hatch sections 1 and 2 of the hatchway cover into the position shown in Fig. 2.

Simultaneously, also sections 3 and 4 are slidably moved closer to the end of the hatchway opening so as to place the section 3 above the rotating mechanism 7. The tip of the long arm of the rotating mechanism 7 is equipped with a wheel that during the rotation of the rotating mechanism with the help of its actuator 8 is brought to contact a backing surface of the section 3. Next, the actuator 8 moves the section 3 into an upright position, whereby also the section 4 hingedly connected to the former will be aligned upright. This end position is illustrated in Fig. 3.

Closing the hatch cover obviously takes place in a reverse order by starting the actuator 8, whereby the actuator first rotates the hatch sections 3 and 4 back into the position shown in Fig. 2. Next, the actuator 6 rotates the sections 1 and 2 horizontal and the closed position of the hatch cover shown in Fig. 1 is thus eventually attained.

To a person versed in the art it is obvious that the invention is not limited to the embodiment described above, but rather, can be varied within the scope of the appended claims. Naturally, a number of different locking and other mechanisms are involved cooperating with the opening/closing mechanism of a hatch cover for the purpose of, e. g., securing the hatch sections into their upright open position. Inasmuch these and a plurality of other details are conventional technology and irrelevant to the object of the invention, they are omitted from the above description and the diagrams.