Particularlv in the case of sea-going vessels, and then primarily military vessels. where it is a major requirement that the vessel shall be"invisible"on radar to the greatest possible degree, it is crucial that there should appear as few irregularities as possible on the part of the vessel that projects above the surface of the water. Therefore there can be allowed no handles nor similar elements on hatches and doors that extend beyond the ship's hull. as these could produce a dispersion of the radar signals which is detectable by enemy radar.

Although the present invention is directed specifically toward vessels of the aforementioned type, it is also applicable for other types of vessels or vehicles for which a maximum reduction of projecting parts is desirable for various reasons, e. g.. in order to reduce air or water resistance. For example, the device could conceivably be used on civilian-type high-speed boats, airplanes or automobiles. The use on buildings where projecting parts are, for one reason or another, not desirable is also conceivable. Nor is the invention limited to use in connection with hatches, but can also be utilized on doors. windows or any part whatsoever of a hull, vehicle body or building which one would want to have the possibility of opening.

The present invention therefore aims to provide a locking device for a hatch or similar structure wherein the surface of the hatch, as well as the adjacent areas, can be left free of projecting elements. It is also an intention that any irregularities on the hatch or the surrounding areas should be as minimal as possible. At the same time. the invention aims to provide an adequate measure of operational comfort and safety.

This is achieved with a locking device in accordance with the characterizing clause of the following claim 1.

The invention will now be described with reference to the attached figures, wherein: Figure 1 is a cross-sectional view through a portion of a hatch and the adjacent frame area or casing, comprising a locking device in accordance with the present invention, Figure 2 is a horizontal plan view of a portion of a hatch equipped with a locking device in accordance with Figure 1, Figure 3a is a horizontal plan view of a portion of a hatch comprising a lock fitting, Figure 3b is a side view of the lock fitting according to Figure 3a, Figure 3c is a horizontal plan view of the lock fitting according to Figure 3a, Figures 5a and 5b are a plan view and a cross-sectional view, respectively, of a portion of a hatch provided with a secondary locking bolt, Figures 6a and 6b are a plan view and a cross-sectional view, respectively, of a portion of a hatch provided with a locking device according to another embodiment of the invention, Figures 7a-7d show a handle for use in connection with the locking device according to the invention, seen from above, from the side, from below, and in detail.

In Figure 1 there is shown a hatch 1, which is constructed as a sandwich structure having a core element 2, an inner surface layer 3 and one or more outer surface layers 4.

Hatch 1 is fitted into a ship's hull, one portion thereof being indicated by reference numeral 5. The ship's hull is likewise constructed as a sandwich structure having a core element 6, an inner surface layer 7 and one or more outer surface layers 8.

Around a hatch opening is provided a frame structure or casing 9, which is made up of a frame core 10 and a frame profile 11. The frame profile has the general shape of a U, defining a hollow 11'. The outer surface layers 8 extend beyond frame profile 11 and up to within a very short distance of the outer surface layer 4 of the hatch, defined by a gap or opening 12.

Hatch 1 is provided with a hatch edge 50. which in cross section comprises a lea 1. extending into the hollow 11'in the U-shape of frame profile 11. In hollow 11'there is positioned a packing 26, against which leg 51 comes into fixed contact when the hatch is closed.

A lock cylinder 13 is inserted through hatch 1 and is by means of a fastening bracket 14 rotatably secured to hatch 1, there being a high-strength insertion piece 1 embedded in hatch 1 to receive fastening screws, not shown. An additional high-strength insertion piece 16 is formed as a sleeve which encloses lock cylinder 13 and ensures that lock cylinder 13 is capable of rotating only about its longitudinal axis and is also incapable of movement relative to hatch 1.

To the inner end of lock cylinder 13 is secured a locking bolt 17. which at the outer extremity thereof is provided with a roller 18. Locking bolt 17 and roller 18 are brought into locked position in engagement with an end piece or striking plate 19, which in turn comprises a glide path 20 for roller 18. Striking plate 19 is attached on the side thereof to frame component 9 via an insertion piece 21, also made of high-strength material.

Lock cylinder 13 is provided at the exterior end thereof with a socket 22, which comprises a recess 23. At the base of recess 23 is formed a circumferential groove 24, defining a shoulder 2. The outer surface 22'of socket 22 is basically flush with the outer face of hatch 1.

In addition to the seal packing 26 embedded in frame profile 11 for sealing against penetration of water and/or gas, there is also provided a so-called EMI packing 27 between frame profile 11 and the edge 50 of hatch 1, for electromagnetic screening.

The EMI packing is in communication on both sides thereof with an EMI screen (not shown). which is built into the system in the form of a brass cover or another conductive material both in the hatch and in the hull.

There is also provided an insertion piece 28 of high-strength material at the outer layer of the hatch for the mounting of lock fittings, as will be explained in more detail below.

Lock cylinder 13 is also connected to a locking bar 29. adapted to transmit rotational movement from lock cylinder 13 to additional locking bolts (see Figure 2).

In Figure 1 there is also shown a circulatory heating cable 30. designed to ensure that the functioning of the hatch is not impaired by frost.

Figure 2 is a plan view of one half of hatch 1 seen from the inside. or more specifically, the side on which the locking device is mounted. The opposite side. not shown. comprises hinges, which may be of any available type having a suitable construction.

Figure 2 shows lock cylinder 13 and locking bolt 17. Also visible is striking plate 19, which comprises a glide path 21 along which roller 18 can roll. Striking plate 19 comprises a wall 52. intended to prevent locking bolt 17 from pivoting too far when rotated into locked position, and thus moving out of its engagement with the striking plate. Lock cylinder 13 is connected via a bar 53 to bar 29, for transmission of the rotational movement to an additional lock cylinder 13'and locking bolt 17'. Lock cylinder 13'and locking bolt 17'are of the same type as lock cylinder 13 and locking bolt 17. and locking bolt 17'is adapted to engage with a striking plate 19'of the same type as striking plate 19, so these parts will therefore not be explained in more detail here.

Bar 29 is also connected to a bar 54, which in turn is connected to a secondary locking device 36. to be explained in more detail below in connection with Figure 5.

Figure 3a is a plan view of a section of hatch 1 and the ship's hull 5 seen from the exterior thereof. Here there is shown a recess 23 in socket 22. and in the illustrated example the recess is shaped like an eight-point star. This eight-point star shape is adapted to receive a conventional crank, of the type generally used on winches on board a sailboat. The winch handle is shown in Figures 7a-7d and is provided with a male part, or chuck, 61 having an octagonal cross section, and a locking member 62 at the outer extremity of chuck 61, which on manipulation of an operating organ 63 is adapted to turn from a first position wherein locking member 62 is completely within the cross section of chuck 61 on the winch handle (broken line in Figure 7d), enabling the insertion of the winch handle chuck 61 into recess 23. Following said insertion. locking member 62 can be turned to a second position (solid line in Figure 7d), wherein locking member 62 projects at least partially beyond the cross section of chuck 61. Locking member 62 then moves behind the gripping edge or shoulder 25 in groove 24. and handle 60 is thereby securely retained in recess 23.

Figure 3a also shows lock fitting 31. which is adapted for mounting on the outer face of the hatch by means of releasable screw connections in insertion piece 28. Lock fitting 31 is shown in more detail in Figures 3b and 3c. Lock fitting 31 consists of a first part 32. which is adapted for attachment to the outside of hatch 1. and a second part 33. which is provided with a male part. or chuck. 34. which includes at the outer extremity thereof a locking member 35.

In the illustrated embodiment eYample. locking member 35 has a rectangular cross section. whereas chuck 34 has a round cross section. The corners of locking member 35 that project beyond the cross section of chuck 34 can. in certain positions, be inserted into recess 23. After chuck 34 and locking member 35 are inserted completely into recess 23. thereby bringing locking member 35 flush with groove 24. the second part 33 of the lock fitting is rotatable relative to socket 22, to bring locking member 35 into position behind gripping edge 25. In this position the second part 33 of the lock fitting can be securely locked to the first part 32 of the lock fitting, for example by means of a padlock.

A lock fitting as mentioned above will further ensure against unauthorized opening of the hatch. for example when the vessel is in port. When the vessel is operative. the first part 32 of lock fitting 31 is removed. leaving the hatch once again free of projecting parts.

Figures 5 and 6 illustrate another embodiment. wherein hatch 1 opens outwards. as opposed to the hatch 1 according to Figure 1. which opens inwards.

In Figures 5a and 5b there is shown a secondary locking device 36. as mentioned briefly in connection with Figure 2. Secondary locking device 36 is intended to prevent the hatch cover from springing up when opened. This will make it possible to equip the hatch with a powerful gas spring to provide for the opening thereof. This would be especially advantageous with heavy hatch covers. Due to secondary locking device 36, the hatch may be opened without the danger that persons in the immediate proximity of the hatch should suddenly have the hatch cover slung powerfully against them. The secondary locking device is also a safeguard against the possibility of the hatch cover being thrown against a nearby person if an overpressure has developed on the inside of the hatch.

Secondary locking device 36 is operatively connected to lock cylinder 13 via bar 29.

Secondary locking device 36 is provided with a cylinder 38. rotatably mounted on the inside of the hatch via a bracket 39, which in turn is screwed securely to a solid insertion piece 40 in hatch 1. Cylinder 38 is provided at the outer end thereof with a secondan locking bolt 41.

On the frame component or casing is provided a secondary striking plate 42. which is fixedlv mounted on casing 9 via insertion piece 43. Secondary striking plate 42 is provided with a foot portion 44 and a sidewall 45. The secondary locking bolt is mounted at a level which is spaced apart from and above foot portion 44.

As shown in Figure 2. secondary locking bolt 41 is in a position outside secondary striking plate 42. on the opposite side of foot portion 44 relative to sidewall 45 when locking bolts 17 and 17'are engaged with striking plates 19 and 19'. In the opposite case. secondary locking bolt 41 will be in a position where it overlaps secondary striking plate 42 (seen in the same direction as in Figure 2) when locking bolts 13 and 13'are rotated out of engagement with striking plates 19 and 19'.

When the hatch is to be opened, the rotational movement of lock cylinder 13 is transferred via bar 29 to cylinder 38. Pivot member (locking bolt) 41 is then rotated to an outswung position above the bracket, or striking plate, 42. When locking bolt 17 and roller 18 engage with striking plate 19 the hatch will be held ajar. with an opening the same size as the distance between secondary striking plate 42 and secondary bolt 41 when the hatch is closed. Bolt 41 meets foot 44 of secondary striking plate 42. and any further opening movement is prevented. Sidewall 45 will prevent bolt 41 from being able to move further in the same direction as the first movement and thereby inadvertently disengaging from secondary striking plate 42.

In this manner, a two-stage opening of the hatch is achieved, which ensures. inter alia, that any overpressure which may have developed on the inside of the hatch is released before the hatch is completely opened.

The embodiment according to Figures 6a and 6b corresponds in its main features to the embodiment according to Figure 1, but illustrates an embodiment of the locking device intended for an outward opening hatch. In this figure, the same reference numerals are used as in Figure 1 for corresponding parts. Inasmuch as this embodiment basically functions in the same manner as the embodiment according to Figure 1. only the

differences between the two will be explained in more depth. On striking plate 19 the glide path 20 is positioned lower down toward casing 9. as opposed to the embodiment according to Figure 1. where the position of glide path 20 is spaced apart from casing 9.

Roller 18 is thus adapted to roll on the upper side (the inward-facing side) of glide path 20. In this embodiment. striking plate 19 also comprises a wall 52. which is intended to prevent bolt 17 from swinging past striking plate 19.

In order to adjust the position of hatch 1 relative to hull 5 in its closed and locked state, the concept according to the invention provides for roller 18 to be replaceable. enabling the mounting of rollers having a larger or smaller diameter. In this manner it is possible to adjust very precisely the position of the hatch, and it is also possible to readjust the hatch easily after a period of use as a result of, for example, wear and tear.

Although the embodiment examples illustrate a hatch and a hull designed with a sandwich construction, the invention is not limited thereto, but can also be used. for example. for hatches and installation walls constructed of, for example, steel or wood.