SUPPORT AND SEAL ARRANGEMENT FOR THE HATCH COVER OF A CARGO SHIP

Abstract: The present invention relates to a support and seal arrangement applicable to the hatch cover (1) of a cargo ship for supporting an essentially rectangular hatch cover (1) and a payload cargo possibly resting thereon and sealing the hatch cover against the edge of the hatch coaming (3), whereby said arrangement comprises at least one support pad (2, 5) located substantially close to the outer edges of the hatch cover and an elongated gasket seal (4) running close to the outer edges of the hatch cover. The invention is implemented by connecting said support pads in a watertight manner to said gasket seal (4).

Description: Support and seal arrangement for the hatch cover of a cargo ship The present invention relates to a support and seal arrangement applicable to the hatch cover of a cargo ship for supporting an essentially rectangular hatch cover and a payload cargo possibly resting thereon and sealing the hatch cover against the edge of the hatch coaming, whereby said arrangement comprises at least one support pad located substantially close to the outer edges of the hatch cover and an elongated gasket seal running close to the outer edges of the hatch cover. The support pad serves to bear the weight of the hatch cover and a payload cargo possibly placed thereon so that the cover can undergo a movement with regard to the edge of the coaming (in order to cope with the deformations of the ship's hull at sea). Additionally, the support pad serves to keep a constant distance between the cover and the hatch coaming irrespective of the superimposed load, whereby an optimal function of the cover seal means is attained. To achieve these objectives, from the prior art there is known, among others, such an arrangement in which the outer edge of the hatch cover has support pads affixed thereto, e.g., two support pads per each edge of the cover, and the lower edge of the cover has an elongated rubber gasket adapted to its lower edge so as to run about its perimeter in a manner sealing the cover against the edge of the hatch coaming. This construction facilitates supporting and sealing the cover so that the cover can move with regard to the edge of the hatch coaming as is necessary to cope with the ship's deformation at high seas. However, this embodiment is hampered by its clumsy size resulting from the large dimensions required by the projecting support members. Simultaneously, also the edges of the hatch coaming must be extended in a compatible manner. Also the hatch cover construction of this prior-art embodiment becomes rather unwieldy due to the separate backing brackets placed under the support members. Moreover, the placement of the hatch covers, particularly their alignment on the coamings is awkward and time-consuming. It is an object of the present invention to provide an entirely novel support and sealing arrangement for a cargo ship hatch cover free from the above- described drawbacks. The arrangement according to the invention is characterized in that the support pads are connected in a watertight manner to the encircling sealing gasket. Therefore, no separate support members attached to the outer edge of the hatch cover and projecting outwardly therefrom are required, thus reducing the external dimensions of the hatch cover with regard to the size of prior-art constructions. The structure of hatch covers also becomes lighter and simpler to manufacture. Furthermore, the new design makes hatch covers easier to mount in place. A preferred embodiment of the invention is characterized in that the support pads are placed at least partially embedded in the gasket seals of the cover. Another preferred embodiment of the invention is characterized in that the gasket seal with the embedded support pads is affixed to the hatch cover and that the bottom surface of the support pad in an unmounted hatch cover is verti- cally situated a level higher than the gasket bottom surface. A further another preferred embodiment of the invention is characterized in that the bottom surface of the support pad in a mounted hatch cover is vertically situated at a substantially equal level with the gasket bottom surface resting against the top surface of the hatch coaming. A still further another preferred embodiment of the invention is characterized in that the bottom surface of the support pad is made of a sealing material. This arrangement provides a continuous seal about the entire hatch cover since the support pad also acts as a part of the gasket seal. Moreover, the support/seal assembly can be made entirely resistant to corrosion. A still another preferred embodiment of the invention is characterized in that the support pad with the portion of seal material attached thereto forms a complete, integrated block that can be affixed in place, particularly to a hatch cover, by means of fastening elements provided on the support pad, such as threaded pin bolts and compatible nuts. In the following, the invention is examined in greater detail with reference to a preferred embodiment illustrated in the appended drawings, in which: Fig. 1 is a perspective view of a hatch cover equipped with a conventional support/seal arrangement and mounted on the edge of a ship's hatch coaming; Fig. 2 is a perspective view of a detail of a conventional hatch cover showing both the support member and the rubber seal thereof; Fig. 3 is a perspective view of a hatch cover equipped with a support pad-seal arrangement according to the invention and mounted on the edge of a ship's hatch coaming; Fig. 4 is a perspective view of a detail of a hatch cover according to the invention showing both the support pad and the rubber seal arrangement thereof; Fig. 5 is a side view of the integrated support pad-seal block according to the invention; Fig. 6 is a sectional end view of the support pad-seal block structure of Fig. 5; Fig. 7 is a side view of the support pad-seal block of Fig. 5 affixed in place and serving in a placed hatch cover; Fig. 8 is an end view of the same support pad-seal block as that shown in Fig. 7; Fig. 9 is a side view of the same support pad-seal block as that shown in Fig. 7 but now having the hatch lifted into a nonworking position; and Fig. 10 is an end view of the support pad-seal block of Fig. 9. Referring to Fig. 1 , therein is shown a state-of-the-art support/seal arrangement for a cargo ship hatch cover 1. As known, a hatch cover is required to close the hatch of a cargo space, whose details are omitted from the diagrams. Conventionally, the outer edges of the hatch cover 1 are provided with support members 2 whose load-bearing surfaces rest on a hatch coaming 3 when the cover is seated on the hatch. While the number of support members may vary, the exemplifying construction of Fig. 1 has two members on each side of the cover. As is evident from Fig. 2, a groove made to the underside edge of the hatch cover has an elongated rubber gasket seal 4 affixed thereto so as to encircle about the perimeter of the entire cover and to seal the cover in watertight manner against the edge of the hatch coaming 3. The drawbacks of this construction are evident from the text above. In Fig. 3 is shown a support/seal arrangement according to the invention for use in a hatch cover. As can be seen from the diagram, there are no projecting, separate support members. Fig. 4 shows the major length of the gasket seal 4 to have a cross section essentially similar to that of conventional constructions. The novel feature of the present invention is to have support pads 5 integrated into the cross section of the encircling gasket seal 4. In practice, the number of support pads can be equal to that used in conventional constructions. However, the number may be varied according to the structure of the hatch cover and the load to be carried by the hatch structure. The characterizing feature of the invention is that the support pads are not located projecting outwardly from the outer edge of the hatch cover, but instead, are integrated into the cross section of the gasket seal. The structure of the support pads themselves can be varied as required. Advantageously, at least a portion of the support pad is made from a metal. Further advantageously, the underside of the support pad has a sealing material attached thereto, whereby a continuous seal is provided about the entire perimeter of the hatch cover. The gasket seal 4 is affixed in the same manner as in cited prior-art construction into a groove made to the edge of the hatch cover 1 as shown in Fig. 4. As is evident from Figs. 3 and 4, the underside of the hatch cover outer perimeter is provided with recesses 6 at the support pads so that a small lateral displacement of the support pads is possible at heavy seas. The support pad may be made slidable and/or elasti- cally deformable to cope with such movements. The rubber gasket seal 4 may be implemented using conventional seal constructions, whereby the seal may be slidable on the coaming or compressible against a shaped metallic backing surface. In Fig. 5 is shown a possible embodiment for an easy-to-mount gasket seal block 4 with its integrated support pad. The support pad-seal block acts as a seal element of a predetermined length that can be readily affixed in a groove made to the hatch cover 1. The seal proper extends in a conventional manner to both sides of the support pad-seal block. The support pad-seal block is provided with two threaded pin bolts 7 that are inserted via compatible holes made to the bottom of the hatch cover edge groove and are then locked in place by means of nuts 8 (Figs. 7 and 8). In Figs. 9 and 10, the hatch cover is shown in a nonworking position, in which the support pad-seal block 4 bears no load. This is the situation when, e.g., the hatch cover is elevated off its place by means of a lift. Then, the bottom surface of the support pad 5 is vertically situated at a level higher than the underside of the gasket seal. In Figs. 7 and 8 is shown the opposite situation, namely, the working position in which the hatch cover is mounted in place. Herein, the bottom surface of the support pad 5 is vertically situated at a substantially equal level with bottom surface of the gasket seal 4 resting against the top surface of the hatch coaming. As the bottom surface of the support pad 5 is made of a sealing material, a continuous seal about the entire hatch coaming is provided. As taught above, the support pads in turn assures that the pressure imposed on the encircling seal stays constant at any point about the hatch cover perimeter, whereby an optimal seal performance is attained. 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. It must be noted, for instance, that the above- described exemplifying embodiment implemented having the rubber gasket seal 4 affixed to the hatch cover 1. Obviously, the seal may as well be adapted to the hatch coaming, whereby the seal rests tightly against the underside of the hatch cover. Furthermore, the support pads need not necessarily be embedded in the seal, but they may as well be connected to each other by any watertight technique, e.g., aligned along a single longitudinal line. The essential feature of the present invention will be appreciated in the integrated, watertight and compact entity formed by the adjoined seal and support pad.

Claims: What is claimed is: 1. Support and seal arrangement applicable to the hatch cover (1) of a cargo ship for supporting an essentially rectangular hatch cover (1) and a payload cargo possibly resting thereon and sealing the hatch cover against the edge of the hatch coaming (3), whereby said arrangement comprises at least one support pad (2, 5) located substantially close to the outer edges of the hatch cover (1) and an elongated gasket seal (4) running close to the outer edges of the hatch cover, characterized in that said support pads are connected in a watertight manner to said gasket seal (4). 2. Support and seal arrangement according to claim 1, characterized in that said support pads (5) are embedded at least partially in said seal (4). 3. Support and seal arrangement according to claim 1 or 2, characterized in that the seal (4) with the embedded support pads (5) is affixed to the hatch cover (1) and that in the nonworking position of the hatch cover, the bottom surface of the support pad (5) is vertically situated at a level higher than the underside of the gasket seal (4). 4. Support and seal arrangement according to any of claims 1-3, characterized in that in the working position of the hatch cover, the bottom surface of the support pad (5) is vertically situated at a substantially equal level with the bottom surface of the gasket seal (4) resting against the top surface of the hatch coaming (3). 5. Support and seal arrangement according to any of claims 1-4, characterized in that the bottom surface of the support pad (5) is made of a sealing material. 6. Support and seal arrangement according to any of claims 1-5, characterized in that the support pad (5) with the portion of seal material (4) attached thereto forms a complete, integrated block that can be affixed in place, particularly to a hatch cover (1), by means of fastening elements provided on the support pad, such as threaded pin bolts (7) and compatible nuts (8).

Inventors: VAEHAEMAA HANNU, VANHANEN MIKA, VAEHAEMAA, HANNU, VANHANEN, MIKA
Applicants: MACGREGOR FIN OY, VAEHAEMAA HANNU, VANHANEN MIKA, MACGREGOR (FIN) OY, VAEHAEMAA, HANNU, VANHANEN, MIKA
Application year: 1999
Main classification: B63B19
IPC codes: B63B19