Hatch covers are used in cargo ships for covering the hatch openings of cargo spaces. Such hatch covers may be hingedly supported by their one edge thus permitting the opening of the hatch cover into, e. g., a vertical position by means of a cooperating actuator connected to said hatch cover in order to provide access into said cargo space. As an exem- plifying reference to such a cargo space hatch cover is cited the international patent application WO 96/25324 filed by the applicant. Also known in the art is a differ- ent type of hatch cover called a"lift-away"hatch cover that is lowered in place and, respectively, elevated away by means of the ship's own hoist or a harbour crane. When the hatch covers are moved away from their protective position above the hatch opening, they are usually stowed in a proper place in the harbour. As a reference to such a hatch cover type, reference is made to SE Pat. No. 449,077.

The present invention is particularly related to the latter type of hatch cover designed to be moved on and off by means of hoists. During such a handling of the hatch cover, there is a great risk of damage to the rubber gaskets of the hatch cover when the hatch cover inadvertently hits other parts of the ship's superstructure during the lift on/off operation. Such bumps occur extremely frequently in conjunction with the lifting of the hatch cover. Particu- larly subject to damage are the gasket sections close to the hatch cover corner areas. Today, no devices or methods are known in the art serving for the protection of hatch cover corners. Only the design of the hatch cover steel structure may be modified to a certain extent so as to give some protection to the seal gaskets. Furthermore, in the art is known a hydraulically actuated"flip seal"

construction. Herein, the"gasket strip"that is hingedly mounted on the hatch cover edges can be rotated into open and closed positions, respectively, with the help of hydraulic cylinders. Such a construction is, however, expensive and requires scheduled maintenance. Moreover, there still remains a risk of gasket damage during the elevation/lowering of the hatch cover.

It is an object of the present invention to provide a pro- tective device aiming to prevent damage to the rubber gasket in the edge areas of the hatch cover and particular- ly in the corner parts of the hatch cover during the handling of the cover. Said goal of the invention is achieved by virtue of the invention characterized in that said protective device comprises a protective plate with a restricted movement, said plate being mounted directly or indirectly to the side of the hatch cover, in the vicinity of the lower edge of the hatch cover corner, whereby said plate in its protective position overlaps horizontally at least partially past the hatch cover end, particularly past the end gaskets thereof, as well as vertically downward past the lower edge of the hatch cover bottom, particularly past the bottom gaskets thereof, and that said protective plate has a point or area capable of receiving a force that during the lowering of the cover in place causes the move- ment of the protective device away from its protective position so as to permit the hatch cover gasket to meet its mating surfaces with a sealing action. In addition to ren- dering an efficient protection to the hatch cover gaskets, the benefits of the embodiment according to the invention include a simple construction, reliable function and low cost of manufacture.

Further preferred embodiments of the invention are dis- closed in the appended dependent claims 2-9.

In the following, the invention is examined in greater detail with reference to the appended drawings, in which: Figure 1 shows an oblique end view of a hatch cover equip- ped with a protective device according to the invention; Figure 2 shows a side view of the operating position of a protective device attached to a hatch cover with the capping plate removed; Figure 3 shows the same view as Fig. 2, now in the phase where the protective plate has moved over a portion of its movement travel; and Figure 4 shows the same view as Figs. 2 and 3, now in the phase where the protective plate has reached its one extreme position.

Referring to Fig. 1, therein is shown a cargo ship hatch cover 1, whose end gaskets are marked with reference nume- ral 2 and lower edge gaskets with reference numeral 3. As mentioned above, this type of cargo space hatch cover ar- ranged to be movable either with the ship's own hoist or a harbour crane is easily subject to bumping of the hatch cover corners during lift on/off operation against other structures of the ship, whereby the gaskets frequently become damaged. To prevent this, the hatch cover 1 can be equipped, advantageously by the lower edges of all its four corners, with a protective device 4 according to the inven- tion. The protective device is preferredly mounted on the side plate 1'of the hatch cover 1.

In Fig. 2 is shown the construction of a preferred embodi- ment of the protective device, whereby here the structure is illustrated for greater clarity without the capping plate 5 shown in Fig. 1. In this embodiment, the protective device according to the invention comprises a base member 6

that can be mounted on the side plate 1'of the hatch cover and a protective plate 7 adapted to move over a restricted path with respect to said base member. In the practicable embodiment illustrated in the drawings, the base member 6 is made from two superimposed plates, of which the lower base member plate is welded to the hatch cover side plate 1'and equipped with inner-thread holes. At respec- tive points, the upper base member plate is provided with holes through which fastening screws can be drawn tight on the lower base member plate. While this can be seen a tech- nically advantageous design in series production, the base member'6 may as well comprise a homogeneous plate or simi- lar piece that is mounted by welding, screws or other methods to the hatch cover side plate 1'. In principle, the invention may be implemented without using any base member.

On the base member 6 are mounted pegs 8,8'and 8"ortho- gonally projecting from the surface of the base member, the number of pegs in the illustrated embodiment being three.

If the base member is omitted, the pegs can be mounted directly on the side plate 1'of the hatch cover. Obvious- ly, while the number of the pegs 8,8'and 8''is not limited and thus a desired number of pegs can be used, reasonably more than one peg must be used. When the design is based on three pegs, they are advantageously located so that the two lowermost pegs 8 and 8'are in the essentially same horizontal plane, while the third peg 8"is arranged above these two so that the vertical plane passing through the third peg remains between the lower pegs, essentially closer to the peg 8'which is located farther from the hatch cover end.

At areas compatible with the pegs 8,8'and 8", the pro- tective plate 7 is provided with guide slots 9,9'and 9gus, advantageously machined through the entire thickness of the protective plate, whereby the movement of the protective plate occurs over a trajectory determined by the coopera-

tion of said pegs and guide slots. In each slot 9,9'and 9", there is an obliquely upward and away from the hatch cover end directed slot portion having a length advanta- geously ranging from a few millimeters to a few hundreds of millimeters, whereby the uppermost slot 9''has subsequent to its said upward slanting slot portion a second slot portion angled essentially orthogonal to said first portion and shaped with the first peg as the center of curvature into a circularly segmental slot portion with a shorter length directed obliquely upward, the farthest from the hatch cover end located slot 9'has subsequent to its said upward'slanting slot portion a second slot portion directed essentially upright with a length shorter than that of the first obliquely directed portion, and the closest to the end of the hatch cover located slot 9 has subsequent to its said upward slanting slot portion a second slot portion with a short length directed essentially horizontally away from the hatch cover end.

The protective plate 7 is designed and mounted so that its front edge A will overlap the end gasket 2 of the hatch cover 1, whereby in the illustrated exemplifying embodiment the protective plate front edge is essentially parallel with the hatch cover front side. Then, the front edge A of the protective plate 7 can receive blows inflicted on the hatch cover end. By virtue of the above-described location and design of the pegs and the guide slots, the protective plate cannot move at all under the force imposed from the direction of the hatch cover end, but rather, gives protec- tion to the corner of the hatch cover. Close to the front edge of the protective plate, the protective plate is also provided with a protective edge B which is essentially orthogonal to the protective plate front edge. This protec- tive edge B serves to receive blows inflicted essentially from below on the hatch cover. In the illustrated embodi- ment, the protective edge B is arranged essentially paral- lel with the lower edge of the hatch cover. Analogously,

blows imposed on the area of the protective edge B cannot move the protective plate.

Next to the protective edge B, the protective plate is pro- vided with a downward extending projection 10 which is located so that the vertical plane passing through the pro- jection 10 will be farther away from the hatch cover end than the vertical plane passing through the peg 8. When the hatch cover 1 is lowered in place, the projection 10 will then meet the backing surface of the hatch opening, and by virtue of the lever mechanism formed by the pegs 8,8'and 8"in'cooperation with the guide slots 9,9'and 9", the protective plate 7 will rotate and slide backward, whereby the rubber gaskets 2,3 of the hatch cover edges can form a tight seal with their respective mating surfaces. In Fig. 3 is shown an intermediate phase of this trajectory and in Fig. 4 the extreme position of the protective plate 7 when the hatch cover is fully seated in place. Not all reference numerals are marked in Figs. 3 and 4, since they would indicate the same elements as in Fig. 2, from which they are easy to locate.

The capping plate 5, which is shown in Fig. 1 only, serves to receive blows inflicted from the sides. This plate can be mounted, e. g., on the ends of the above-described pegs 8,8'and 8". Analogously, the capping plate 5 also serves to prevent the movement of the protective plate 7 under blows imposed toward the protective plate.

When necessary, the hatch coaming (that is, a collar-like of the ship's deck on which the hatch cover is seated) can be provided with a wear-resistant and/or low-friction backing plate, such as a steel plate, which serves as a backing surface for the protective plate 7. Such a backing plate is not shown in the drawings and its use is not mandatory.

To those versed in the art it is obvious that the invention is not limited to the embodiments described above, but rather, can be varied within the scope and spirit of the appended claims. The exemplifying embodiment illustrated in the drawings has the base member provided with pegs attached or formed thereto, whereby the protective plate has compatible guide slots. Obviously, the construction may be implemented using these elements in reversed positions.

It is further possible to replace pegs by other types of guide elements. For instance, various shapes of projections with compatible recesses can serve this purpose.