DE19646793A1 - Suspended, low friction and wear hatch cover mounting for container ships - Google Patents

Abstract

The vertical force from the hatch cover (1) is directed through a movable element (2) located at right angles to the displacement, and from this element, which has a long length in relation to the displacement, is directed onto the ship. Owing to the length of the element and the choice of the spherical bearing surfaces (3,4), the horizontal movements between the hatch cover and hatch coaming are converted into rotational movements on the bearing faces.

Description

In particular on hatch covers of container ships, a high proportion of the total load is driven. Because of the high elastic deformations of the hatch cover support level in the sea, there are high relative movements (e.g. up to a maximum of approx. 40 mm) between hatch cover and ship. Due to the high load on the supports (typically e.g. approx. 800 kN), the following undesirable phenomena occur under the influence of these displacements:

• - Wear of the supports
• - High horizontal load transfers from the frictional forces in the hatch cover
• - High horizontal load transfers from the frictional forces into the hatch
• - noise problems

The following solutions are known to deal with this problem:

• - Enlargement of the support areas
• - Choice of low-friction material combinations (different types of steel, but also Bronze and plastics)
• - Easily replaceable wear-elastic elements in the support area to avoid edge pressures caused by deformation of the hatch cover beam.
• - Use of rubber elements in which the displacement within the element to be held.

(Patents or patent applications are known by Mac GREGOR under the names
UNIPAD pat.no. DE 39 04 602 C2
FLEMPAD
by the company MACOR, this development was described in detail in an article in the magazine HANSA in issue No. 9 in 1994.)

The known solutions try to avoid the negative influences from the horizontal To reduce displacement in the support level. Because of the unsafe  The classification societies take friction factors into account high horizontal forces required. The permissible surface pressures are low, therefore there are large bearing surfaces. Due to the inevitable wear and tear Lifetime of the elements limited, the exchange is very cost-intensive. Only the "FLEXIPAD" solution goes a different way. Here, the Horizontal displacement caught in a rubber element. The allowable Surface pressure is low. That slides above a certain displacement Element also on the support level with corresponding consequences (wear)

Purpose of the invention

The invention has set itself the task of avoiding the disadvantages mentioned above. The supports should be designed so that:

• - the wear becomes insignificant during the service life
• - these become maintenance-free
• - Large horizontal shifts can be easily recorded
• - Elastic deformations of the hatch cover supports (deflections) without any problems can be included
• - only very low horizontal forces in the area of the supports on hatch covers and Act on hatch fill
• - The adaptation of the storage areas is greatly simplified.

Representation of the invention (see attached drawing of the application example)

The invention solves the problems by a movable element, z. B. between the support contact surfaces of the hatch cover 1 and the hatch fill 5 . B. a pendulum support 2 is inserted. This element converts the horizontal displacement into two rotary movements on the upper and lower edge of the movable element 3 and 4 . The length of the support allows the size of this rotary movement to be converted into very small values. A spherical design of the contact surfaces 3 and 4 ensures a 100% contact pattern of the bearing surfaces. As a result, the permissible surface pressure can be selected to be very high, so the storage area can be kept small. (According to the regulations of Germanischer Lloyd e.g. 3 times as high as with normal, flat supports (GL regulations chapter 117 C 5.2)) The problem of edge pressure is completely avoided by the spherical shape of the bearing elements. The horizontal forces on the sill and lid become very small, they are in relation to the bearing force like the tangent of the max. Angle of inclination, for an element 10 times the length of the max. Horizontal displacement, for example, does not exceed 10% of the support force. As a result, the hatch cover (and also the hatch cover) need not be reinforced or only slightly reinforced in these areas. The fact that substantial wear no longer takes place increases the service life of the rubber seals 6 considerably since the rubber impression of the hatch cover seal remains constant over the service life of the ship.

By inserting such movable elements 2 (e.g. pendulum supports), the cover is kept floating above the surface level, the elements can be accommodated within the height of the cover, i.e. above the surface profile, or protrude down to below the sealing level. They can be arranged inside the side panel of the lid or outside, they can be lifted off when opening the lid or they can remain on the sill.

An application example of the invention shows the attached drawing, in this case a pendulum support is outside the lid and shown within the overall height of the lid.

Claims (1)

Floating, low-friction and low-wear hatch cover mounting, especially for highly loaded hatch covers on ships with large relative movements between hatch cover and hatch sill, characterized in that the vertical force is guided by the hatch cover ( 1 ) via a movable element ( 2 ) arranged at right angles to the displacement, from this element , which has a long length in relation to the displacement, is directed into the ship ( 5 ). By the length of the element and by choosing z. B. spherical bearing surfaces ( 3 , 4 ), the horizontal movements between hatch cover and hatch filling are converted into rotary movements in the bearing surfaces.