The invention relates to a propulsion drive unit for a water vessel, said unit comprising driving engine means, propulsion device means connected to said engine and control and peripheral apparatuses for said means. The invention further relates to a method for assembling the machinery in a vessel, said machinery comprising at least a driving engine means, a propulsion device unit comprising propeller means and further apparatuses needed for the controlling of said means. The invention further comprises mould means for the manufacture of a flange means according to the invention.

In most conventional waterborne vessels the propulsion means comprise a driving engine, usually an internal combustion engine which is mounted in said vessel, the driving shaft of said engine being connected to a propulsion device comprising a propeller screw. Said propeller screw produces a water stream, said stream being directed backwards with respect to said vessel, and due to the reaction force of said stream said vessel moves in a forward direction. Said propeller screw must hence be located in the water surrounding said vessel or in a special space which is in direct contact which the water.

For said driving engine there are two principles for the location. Smaller driving engines, that is so called outboard motor arrangements, may be located on the outer side of the hull of the vessel and directly connected to said propulsion means. More powerful engines are, however, preferably located inside the hull of the vessel, suitably into a special engine space where said engine is well protected and easy to main¬ tain. In this case there is, however, the problem that a driving shaft on one point must penetrate the hull of the vessel, so that said propeller screw will be in contact with the surrounding water. This problem occurs ^' both with traditional simple direct driven propeller screws as also with

more complicated propulsion apparatuses like stern drive units or water jet propulsion units, which apparatuses usually are located in the stern of the vessel. Drive units for sailing boats, said units extending downwardly through the bottom of the hull of the boat, often have a driving engine and a pro¬ peller screw apparatus combined into a unit, a mounting flange then extending between them, said flange being fitted in an aperture in said bottom. Because the arrangement in sailing boats is an auxiliary driving unit the whole unit may be made rather small, and the driving unit extending through the bottom of the hull may be small.

In both stern drives and water jet propulsion drives the con¬ ventional fitting method is, however, that the driving unit comprises, at the point where it passes through said bottom, a flange or the like. Said flange may be adjustable and it is fastened into an aperture made in the transom of the vessel. After this operation the engine and its necessary auxiliary equipment are fastened on an engine bed located or made in the engine space, so that the driving shaft of the engine is, as exactly as possible, in alignment with the driving shaft of said propulsion device. Said shafts are then interconnected. Usually also further equipment necessary for the use of the vessel and for the function of the engine are mounted in said engine space, said equipment comprising e. g. the actual control devices for engine and propulsion means, ventilation fans for the engine space, starting batteries, filters for cooling water and so on. Further the exhaust pipes for the engine usually are lead as separate piping through the wall of the hull.

All said assembling is a work demanding precision, and especially in small vessels this work must be performed in the rather cramped circumstances in the engine space. Especially the fitting of the engine and the propulsion unit to each other demands special precision, and even a small eccentricity leads to a loss in efficiency, vibrations and to a rapid

wearing of the parts. In order to facilitate the alignment there are sometimes arranged special alignment or fitting means, which, however, unnecessarily increase the weight of the vessel, the mounting work proper still being done under difficult circumstances.

Earlier attempts have been made to solve this problem in different ways, so that the engine and the propulsion means form an entity, which is mounted into the vessel in a manner discussed in context of the engine units for sailing boats. GB-publication No 1 226 358 discloses a driving unit which unit as a whole may be mounted in a vessel. Said device comprises a bottom portion and edges surrounding all sides of said bottom portion, and in said device the engine and the propeller unit are fixedly mounted. Said device is fitted into an "engine well" arranged in the bottom of the vessel, said well having edges extending up over the surface level of the water. FR-publication No 1 321 564 discloses a water jet pro¬ pulsion unit which comprises an entity formed of an engine and a propulsion unit, said engine being fixedly connected to said propulsion unit so that the engine shaft is vertical. Both arrangements mentioned above will limit the design of the vessel to a rather high extent.

IT-publication No 32230 A/72 discloses a propulsion unit which as such forms a part of the stern of a vessel. In connection to the water jet propulsion devices there is an engine bed for a separate driving engine as well as a through for the exhaust pipe. The drawback of this arrangement is that its design is rather fixedly predetermined, which also strongly limits the design of the vessel. In said arrangement the location of the exhaust pipe is chosen fixedly incorrect.

In order to facilitate the mounting of an engine located in¬ side the hull of a vessel and a propulsion unit located out¬ side the hull, without restricting the design of the vessel, as well as to bring any further assembly work to be performed

under factory-like conditions instead of in a narrow engine space the present inventor has developed the assembling method as well as the driving device unit according to the invention, the characteristics of said method and unit being evident from the enclosed claims.

Thus it is characteristic for the method according to the invention, that said driving engine means and said propulsion device means are mounted each on its own side of a flange means, said flange means essentially adapting to the design of said vessel, whereby the driving shaft extends from said engine to said propulsion device through said flange means, and that an essential part of any control and auxiliary devices to be connected to the driving machinery and said propulsion device as well as of any further engine space equipment are mounted on said flange means, and that said flange means with said devices attached thereto as such in an assembled state is attached to an aperture made in the hull of the vessel, so that said flange means completely covers said aperture and at the same at that position forms an operating part of the hull structure of said vessel. For the propulsion device unit according to the invention it is, on the other hand, characteristic, that between said driving engine means and said propulsion device means there is a separate flange means, which corresponds to the design of the hull of any respective vessel, said flange means comprising at least fastenings for said driving engine means and/or said pro¬ pulsion device means. For each type of vessel said flange means suitably is realized in such a way, that the bottom portion angle and the inclination of the stern portion exactly correspond to the form of the vessel in question. In order to provide this feature a mould means according to the invention has been developed, the characteristics of which is that said mould means comprises mould boards for said bottom portions, said boards being interconnected by hinges and adjustable with respect to their mutual inclination, and that adjoining to said mould boards there is a mould board for the transom

portion, the inclination of said mould board being adjustable.

The invention will now be described in more detail with reference to the enclosed figures, wherein

Fig 1. shows, in a schematic section as seen from the side at the location of the exhaust pipe, a driving device unit according to the invention, as well as an enlarged detail figure of one embodiment of the connection between said flange means and the hull of a vessel.

Fig 2. shows, in axonometric projection seen from the inside of the vessel, one embodiment of the driving device unit according to the invention,

Fig 3. shows, as seen from the back, the stern portion of a vessel, from which a portion corresponding to the flange means has been removed in accordance with the invention, and

Fig 4. shows, schematically in an axonometric projection, a mould according to the invention.

According to Figure 1 a drive unit 1 comprises a driving engine 2 and a propulsion device 3, which in the embodiment shown is a water jet propulsion device. From said driving engine a driving shaft 4 extends, possibly via flexible and/or connecting means 5 to the driving shaft 6 of said propulsion device 3, said shaft 6 carrying' a propeller screw 8 which stays in contact with the water. Said driving engine now comprises suitably flexible and/or adjustable supporting lugs 30 and said propulsion device 3 comprises a fastening flange 29.

Between said driving engine 2 and said propulsion device 3 there is a flange means 9 conforming to the design of the vessel' s hull. In the shown embodiment said flange means 9 comprises a distinct bottom portion 10 and a correspondingly distinct stern portion 11. In some cases, e.g. in boats with a tapering stern, no clear distinction between bottom and stern

can be made, and said flange means 9 then extends essentially uniformly curving up from the bottom to the upper portions of the stern. Especially with this type of boats the fitting of a water jet propulsion drive traditionally has been complicated, since it has been difficult to arrange a clear fastening point in a canoe-shaped boat. Here the arrangement according to the invention brings considerable advantages.

According to the invention said flange means 9 comprises edge portions 12, 13, which are shown in Figure 2 in greater detail. Said edge portions suitably comprise a lap portion 15 where said flange means 9 is fastened to the vessel' s hull 16 e. g. with bolts or rivets and suitably using a sealant. An aperture-like portion 17 (see Figure 3) corresponding to said flange means 9 has been made in the said hull 16 prior to the fitting. In the shown embodiment said aperture-like portion 17 comprises a considerable portion of the transom structure of the vessel's hull 16. In connection with the fitting of said apparatus unit this hull portion of the vessel is replaced by a corresponding portion of said flange means 9, and after the fitting said flange portion constitutes a working part of the vessel' s hull.

At least at said edge portions 12, 13 said flange means 9 closely corresponds to the design of the ^' vessel' ε hull, the more central portions of said flange means 9 being designed on one hand in accordance with the design of the vessel' ε hull and on the other hand in accordance with the designs of the devices 2, 3 to be fitted. As subsequently will be made more evident it is very easy to adjust the respective mutual positions of said portions with the aid of the mould arrange¬ ment according to the invention. Thus said flange means 9 is designed to replace an integrally structured portion of the vessel' s hull. Prior to the fitting of said drive unit provided with said flange means said portion, which corresponds to said aperture 17, will either be removed from the transom and/or from the stern portion of the bottom of an

existing vessel 16, or a vessel 16 may already from the beginning be built so that said aperture portion 17, which often may be quite considerable in size, is left open. Said flange means 9 with any devices fixed thereto will later be fitted to replace said portion 17. This' fitting may be per¬ formed very rapidly.

In said flange means 9 a engine bed 18 constitutes a very essential part. Said driving engine 2 is mounted on said engine bed 18 to stand on said fastening lugs 30 so that said driving shaft 4 is exactly in centered alignment with said shaft 6 of said propulsion device. Correspondingly, in the shown embodiment, the stern portion 11 of said flange means 9 comprises a fitting portion for said propulsion device, to which portion said fastening flange 29 of said propulsion device is attached on a support structure 28 suitably formed in said flange means 9. According to the invention the actual assembling may be performed under factory-like circumstances and apart from the often crowded engine space in the vessel. The parts may thus be easily and precisely disposed in relation to each other and the whole assembled drive unit 1 may be tested, which for drive units already assembled in a vessel until now has been quite difficult and which has demanded very extensive and difficult arrangements. The fitting of all kinds of engine space apparatuses 19, 20, 21, 23 as well as control devices 25, 27 for the engine and the propulsion device to a loose flange means 9 is correspondingly considerably easier than fitting them into a ready made engine space.

Preferably said flange means 9 is designed so that its shape replaces a respective part of an existing vessel, so that said flange means in fitted condition constitutes an integral portion of the vessel' s water tight hull structure. For each vessel design a flange means 9 corresponding to that vessel type may easily be formed from fibre glass reinforced resin or the like material, onto which flange means 9 any equipment to

be located in said engine space or outside the vessel' s hull are fitted. Said flange means 9 then comprises proper fasten¬ ing points for said equipment, the design of said fastening points preferably closely corresponding to the design of the device to be fitted. Further said flange means 9 in some cases may comprise any necessary reinforcement and support formations so that said flange means 9 in fitted condition integrally may form a part of the vessel' s hull.

On said flange means 9 there is fitted, beεideε said driving engine 2 and said propulsion device 3, suitably all essential control and auxiliary devices for said engine and said pro¬ pulsion device. In a water jet application the stern portion of said flange means 9 thus comprises openings for the control means 25 for a directing gate means 24 and the for control means 27 for a directing nozzle 26 for the water jet in said water jet drive 3. Correspondingly in a stern drive appli¬ cation lift means for the driving device are pre-assembled on said flange means 9. Besides the arrangement of said devices it is favourable to fit also other engine space apparatuses, e.g. an engine space fan 19 and an engine space bilge pump 20 onto said flange means 9. The transom portion 11 of said flange means 9 suitably comprises ready made vent openings 21 and a duct for an exhaust pipe complete with "swan neck" 23 and muffler. Further said flange means 9 may comprise pre- fitted adjustable trim fins or the like, the transducer for an echo depth finder and so on.

All essential technical details related to the driving and maneuvering of the vessel may thus be assembled onto said flange means 9 under factory-like conditions and in free space, whereby the entity comprising an inboard engine functionally corresponds to the function of an outboard motor fitted outside the vessel' s hull. Apart from this aspect, however, there is an essential advantage with the arrangement according to the invention, that is that the engine and the propulsion system may be chosen to correspond to the use of

the vessel substantially more freely than is the case with an outboard motor alternative. The location of the different components may also be chosen rather freely. One objective of the invention actually is to conform the fitting of the drive devices so that the engine and the propulsion unit while being essentially standard in design may be fitted in each vessel on a flange portion primarily of the same design. The outer portions of the flange means may on the other hand be arranged in detail to correspond to the form of the hull of any specific vessel. Further for the selected type of vessel certain properties depending on the more detailed design of the stern structure may be chosen to correspond to the specific use of the vessel and to the chosen propulsion system. Besides having a design in accordance to criteria demanded by the design of the vessel' s hull and the drive apparatus said flange means 9 also may be actually shaped e. g. considering the hydrodynamic properties of the vesεel' s stern portion.

In connection with water jet propulsion drives the arrangement according to the invention is especially advantageous since in said arrangement the thrust angle of the jet drive with respect to the vessel' s hull can be determined very exactly. In conventional fitting arrangements there is always the risk, that the thrust angle, that is the angle of the backwards directed jet stream with respect to the bottom of the vessel, may slightly vary. This angle has a very considerable influence on the running properties of the vessel, and the accepted deviation is of the order of one degree. With con¬ ventional water jet propulsion drives an afterwards performed adjustment of this angle is extremely difficult, it thus being important that the angle is correct from the start. The arrangement according to the invention here ascertains that the correct thrust angle for the vessel type always will be achieved once said angle has been determined.

Different vessels demand flange means 9 of different designs. Especially the V-angle of the bottom portion 10 must correspond to the bottom angle of said vessel, and correspondingly the transom portion 11 normally should extend at an angle with respect to the bottom which angle corresponds to that ^' of the original transom. Permanent mould structures may be produced for long series of standard type boats, but for individual vessels, short series of vesselε and for the purpose of testing the water jet drive thrust angles for standard type vessels a special mould structure has been developed, wherein the above mentioned angles may be easily adjusted in relation to each other and e.g. to a propulsion device.

A mould structure according to the invention comprises a number of essentially board like mould bodies 31, 32, 33 which are interconnected by a number of hinges. In a preferred embodiment said mould boards 31, 32 for the bottom portion 10 are adjustable, by the aid of hinges 37, in relation to a central fixed portion 34, and said mould board 33 for the transom portion 11 is correspondingly adjustable by the aid of hinges 38. Said fixed portion suitably comprises mould portions 36 for the suction inlet opening structure 35 and/or for a transom attachment flange 29 of a water jet propulsion drive, the mutual angles between said attachment areas being exactly defined in accordance with the drive device 3 to be used and the thrust angle it requires. In an embodiment according to Figure 4 these fastening areas comprise mould means 36 for a suction tunnel and for said transom flange. Said fixed portion 34 suitably comprises a narrow bottom wedge piece which extends forwards from the transom portion. In one embodiment said bottom wedge piece terminates in such a way that said bottom portion moulds 31, 32 in front of said bottom wedge piece are in close contact to each other.

Since said mould boards 31, 32, 33, 34 and said transom mould 36 are three-dimensionally movable with respect to each other it is necessary to keep the arrangement of them somewhat loose. E. g. silicone tape or special stuffing pieces are used in the remaining open areas 39 during the manufacturing of a flange means. In the mould means according to the invention said flange means 9 itself is suitably manufactured from fibre glass reinforced resin or in any other known manner. Prior to the manufacturing edge beads are fastened to said mould, which beads in said flange means form said edge lap portions 15.

With a flange means manufactured in a mould means described above an entire drive unit according to the invention may be fastened, in a manner similar to that of a normal outboard motor, to a vessel chosen reasonably arbitrarily. A complete drive device entity 1 is lifted, from the rear or from the inside, into said opening 17 in the stern of said vessel, and it is fastened with bolts or the like at its edgings. A sealant is spread preferably on the seam portions prior to the fastening, but it is also possible to arrange the seam lap portion to permanently comprise a sealing member. Of the normal fitting procedures there suitably mainly remains only the steps of arranging the fuel feed, connecting some operative devices relating to the steering and the electrical connections for the control of the motor.

The invention has been described above with reference mainly to a water jet propulsion drive, but it is obvious, that the same arrangement in accordance with the invention may be used also in connection with e. g. a stern drive (in an inboard motor arrangement) or even with a traditional direct propeller screw drive.

Quite often it is of advantage, that the transport distances for the actual vessels are kept short in order to minimize the transport costs. For this purpose a drive unit 1 according to the invention is especially favourable, since its manufacture

and any assembling work requiring special precision may be done under factory-like conditions and suitably in long series, while on the other hand the fitting of said unit 1 into a specific vessel may be done for example at the manu¬ facturer of said vessel. In the same manner a drive unit 1 may, in some cases, relatively easily be detached for more extensive service measures.