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Title:
SYSTEM AND APPARATUS FOR USING A WATER JET ENGINE AS A WATER PUMP AND A STEERING NOZZLE FOR A WATER JET ENGINE
Document Type and Number:
WIPO Patent Application WO/2001/010710
Kind Code:
A1
Abstract:
The invention relates to the steering nozzle (5) of a water jet engine (1), and to a system and a method for using the water jet engine (1) as a water pump. In the system the pumped water is taken from the water jet generated by the engine (1) with the aid of a tubular water jet control member (12) mounted against or within the steering nozzle (5). The jet port (6) at the end (16) of the steering nozzle (5) can be arranged to be movable in the direction of the water jet flowing out through the outlet port (4) and against it.

Inventors:
Laakso, Kari (Marjapolku 4 Vaasa, FIN-65230, FI)
Application Number:
PCT/FI2000/000660
Publication Date:
February 15, 2001
Filing Date:
July 26, 2000
Export Citation:
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Assignee:
ALULAAKSO OY (Vasaratie 16 Vaasa, FIN-65230, FI)
Laakso, Kari (Marjapolku 4 Vaasa, FIN-65230, FI)
International Classes:
B63H11/08; B63J3/02; (IPC1-7): B63H11/107
Foreign References:
US5516313A1996-05-14
US4832632A1989-05-23
US3970030A1976-07-20
Attorney, Agent or Firm:
TURUN PATENTTITOIMISTO OY (P.O. Box 99 Turku, FIN-20521, FI)
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Claims:
Claims
1. A system for using a water jet engine (1) as a water pump, the water jet engine (1) comprising a water channel (2) intake port, a water channel (2), a turbine (3) for intensifying the water flow in the water channel (2), a water channel outlet port (4), and a steering nozzle (5) for steering the water coming through the outlet port (4), whereby the water jet being arranged to flow out through the outlet port (4) is arranged to flow into the steering nozzle (5) through its first end (22), and there being a jet port (6) at the second end (23) of the steering nozzle (5) for directing the water out through the steering nozzle (5) into a desired direction, the system comprising a frame structure (8) arranged substantially stationary regarding the water jet engine (1), at least one motion member (10), which is arranged in the frame structure (8) and arranged to be movable in relation to the frame structure (8), for instance a shaft (10), which is arranged to be turnable around a hinge (11), a tubelike water jet control member (12) arranged in at least one motion member (10), the control member having a first end (13) and a second end (14), which motion member (10) and control member (12) are arranged to be movable between at least two different positions, i. e. the pumping position, where the control member (12) is arranged by its first end (13) in connection with the steering nozzle (5) for directing the pumped water from the first end (13) into the control member (12), through the control member (12) and out through the second end (14) of the control member (12), and the idle position, where the control member (12) is arranged away from the position in front of the water jet in order to enable unhindered operation of the water jet engine (1), characterised in that the opening of the first end (13) of the control member has at least one diameter which is smaller than the second end (23) of the steering nozzle, which substantially prevents the steering nozzle (5) from being pushed into the control member (12) in the pumping position.
2. A system for using a water jet engine (1) as a water pump, the water jet engine (1) comprising a water channel (2) intake port, a water channel (2), a turbine (3) for intensifying the water flow in the water channel (2), a water channel outlet port (4), and a steering nozzle (5) for steering the water coming through the outlet port (4), whereby the water jet being arranged to flow out through the outlet port (4) is arranged to flow into the steering nozzle (5) through its first end (22), and there being a jet port (6) at the second end (23) of the steering nozzle (5) for directing the water out through the steering nozzle (5) into a desired direction, the system comprising a frame structure (8) arranged substantially stationary regarding the water jet engine (1), at least one motion member (10), which is arranged in the frame structure (8) and arranged to be movable in relation to the frame structure (8), for instance a shaft (10), which is arranged to be turnable around a hinge (11), a tubelike water jet control member (12) arranged in at least one motion member (10), the control member having a first end (13) and a second end (14), which motion member (10) and control member (12) are arranged to be movable between at least two different positions, i. e. the pumping position, where the control member (12) is arranged by its first end (13) in connection with the steering nozzle (5) for directing the pumped water from the first end (13) into the control member (12), through the control member (12) and out through the second end (14) of the control member (12), and the idle position, where the control member (12) is arranged away from the position in front of the water jet in order to enable unhindered operation of the water jet engine (1), characterised in that in the pumping position the first end (13) of the water jet control member (12) is arranged inside the steering nozzle (5) via the jet port (6) of the steering nozzle (5) of the water jet engine (1).
3. A system according to claim 2, characterised in that the water jet engine (1) is arranged to be the propulsion power source in a watercraft.
4. A system according to claim 2 or 3, characterised in that the steering nozzle (5) is arranged to be turnable in relation to the water jet which is arranged to flow through the outlet port (4).
5. A system according to any previous claim 2 to 4, characterised in that the at least one motion member (10) is arranged to be moved by a motor, advantageously by an electric or hydraulic motor.
6. A system according to any previous claim 2 to 5, characterised in that the frame structure (8) is arranged to be fastened between the hull (9) of the watercraft and the steering nozzle (5).
7. A system according to any previous claim 2 to 6, characterised in that at the second end (14) of the water jet control member (12) there is one or more fasteners (17) for a connection, such as a fire hose or a watering hose, a pipe or the like, in order to direct the pumped water along said connection to a desired place.
8. A system according to any previous claim 2 to 7, characterised in that the system comprises a connection communicating with the pumped water flow in order to add an additive, such as foaming agent used in fire fighting, to the water flow.
9. A system according to any previous claim 2 to 8, characterised in that in the pumping position the first end (13) of the water jet control member (12) is arranged within the steering nozzle (5) up to the outlet port (4) of the water channel (2) and arranged in substantially water tight communication with the outlet port (4) of the water channel (2).
10. A system according to any previous claim 2 to 9, characterised in that the water jet control member (12) comprises at least two tubular members (15,16) which are arranged one at least partly within the other and to be movable in relation to each other, and of which the first one (15) is arranged substantially fixedly on at least one motion member (10), and that in the pumping position at least the first end (13) of the second tubular member (16) is arranged within the steering nozzle (5).
11. A system according to claim 10, characterised in that said at least two tubular members (15,16) of the control member (12) are arranged to be movable in relation to each other with the aid of a motor, advantageously an electric or hydraulic motor.
12. A method for using a water jet engine (1) as a water pump, the water jet engine (1) comprising a water channel (2) intake port, a water channel (2), a turbine for intensifying the water flow in the water channel (2), and a water channel outlet port (4), as well as a steering nozzle (5) for steering the water jet discharged through the outlet port (4), in which method the pumped water is directed into the first end (13) of a tubular water jet control member (12) arranged in connection with the steering nozzle (5), through the control member (12) and out through the second end (14) of the control member (12), characterised in that the first end (13) of the water jet control member (12) is arranged through the jet port (6) of the steering nozzle (5) of the water jet engine (1) into the steering nozzle (5).
13. A system for using a water jet engine (1) as a water pump, the water jet engine (1) comprising a water channel (2) intake port, a water channel (2), a turbine (3) for intensifying the water flow in the water channel (2), a water channel outlet port (4), and a steering nozzle (5) for steering the water coming from the outlet port (4), whereby the water jet being arranged to flow out through the outlet port (4) is arranged to flow into the steering nozzle (5) through its first end (22), and there being a jet port (6) at the second end (23) of the steering nozzle (5) for directing the water out through the steering nozzle (5) into a desired direction, the system comprising a frame structure (8) arranged substantially stationary regarding the water jet engine (1), at least one motion member (10), which is arranged in the frame structure (8) and arranged to be movable in relation to the frame structure (8), for instance a shaft (10), which is arranged to be turnable around a hinge (11), a tubelike water jet control member (12) arranged in at least one motion member (10), the control member having a first end (13) and a second end (14), which motion member (10) and control member (12) are arranged to be movable between at least two different positions, i. e. the pumping position, where the control member (12) is arranged by its first end (13) in connection with the steering nozzle (5) for directing the pumped water from the first end (13) into the control member (12), through the control member (12) and out through the second end (14) of the control member (12), and the idle position, where the control member (12) is arranged away from the position in front of the water jet in order to enable the unhindered operation of the water jet engine (1), characterised in that moving members (19) are arranged in connection with the steering nozzle (5) in order to move the jet port (6) of the second end (23) of the steering nozzle (5) in the direction of the water jet flowing from the outlet port (4) and against it, and that in the pumping position the position of the jet port (6) is displaced against the flow direction of the water jet, as compared to its idle position.
14. A system according to claim 13, characterised in that the whole steering nozzle (5) is arranged to be movable in the direction of the water jet flowing from the outlet port (4) and against it.
15. A system according to claim 13 or 14, characterised in that in the pumping position the jet port (6) of the steering nozzle (5) is arranged, in the direction of the water jet arranged to flow out through the outlet port (4), at the position of the outlet port (4), whereby the first end (13) of the water jet control member (12) is arranged in a substantially water tight communication with the outlet port (4) of the water channel (2).
16. A system according to any previous claim 13 to 15, characterised in that in the pumping position the first end (22) of the steering nozzle is in a substantially water tight communication with a plane (21), which is substantially perpendicular to the direction of the water jet, for instance the transom of the boat (9) using the water jet engine as its propelling power source.
17. A system according to any previous claim 13 to 16, characterised in that the moving members (19) comprise a motor, advantageously an electric or hydraulic motor, in order to control the position of the jet port (6) of the steering nozzle (5) in the direction of the water jet arranged to flow through the outlet port (4).
18. A system according to any previous claim 13 to 17, characterised in that in the pumping position the first end (13) of the water jet control member (12) is arranged within the steering nozzle (5) through the jet port (6) of the steering nozzle (5) of the water jet engine (1), advantageously up to the water channel's (2) outlet port (4), and arranged in a substantially water tight communication with the outlet port (4) of the water channel (2).
19. A steering nozzle (5) of a water jet engine (1), which comprises a water channel (2) intake port, a water channel (2), a turbine (3) for intensifying the water flow in the water channel (2), a water channel outlet port (4), whereby the water jet arranged to flow from the outlet port (4) is arranged to flow into the steering nozzle (5) through its first end (22), whereby there is a jet port (6) at the second end (23) of the steering nozzle (5) for directing the water out through the steering nozzle (5) into a desired direction, characterised in that moving members (19) are arranged in connection with the steering nozzle (5) for moving the jet port (6) of the second end (23) of the steering nozzle (5) in the direction of the water jet flowing from the outlet port (4) and against it.
Description:
SYSTEM AND APPARATUS FOR USING A WATER JET ENGINE AS A WATER PUMP AND A STEERING NOZZLE FOR A WATER JET ENGINE The invention relates to a system and a method according to the preambles of the independent claims presented below, for using a water jet engine as a water pump.

The invention relates further to a water jet steering nozzle for a water jet engine, which nozzle is applicable in the system and method according to the invention.

When water is temporarily needed from water systems, such as a sea, a lake or a river, the water is generally pumped with pumps that are transported over land.

Such transportable pump equipment is often bulky and difficult to transport, and it can not reach all shores by land. A water pump mounted in a watercraft, such as a boat, is easy to transport to any shore of a water system. For instance in the archipelago it is often faster to travel by water than along roads. Particularly for the fire brigades it is important to rapidly reach also the shores of water systems.

Water pumps are also needed in the heart of water systems, for instance in underwater works on bridge construction sites. Generally it is more cumbersome to transport bulky equipment on a barge or the like to a construction site located in the middle of a water system than to bring a boat or the like to the site.

A water jet engine, which is intended to be the propulsion source for a watercraft, is in the present invention used for pumping water. The use of a water jet engine to pump water by directing the water jet generated by a motor wholly or partly to other purposes than the propulsion of the vessel is known for instance from the US patent publication 5299960, which presents a watercraft driven by a water jet engine where a branch is mounted in the water jet outlet port in order to branch the water flow into two outlets. The branch has two outlet ports, the first one of which acts as the outlet for the water jet required for propelling the watercraft, and water to be pumped is directed to the other one, for instance for the purpose of extinguishing a fire. The water is guided into the pumping pipe by closing a valve mounted in the propulsion pipe. The US patent publication 5516313 presents in one of its examples an apparatus intended for fire fighting where the water to be pumped is directed to a fire hose by mounting a guiding pipe after the steering nozzle of the watercraft for guiding the water jet via the guiding pipe into the fire hose. When the vehicle shall be operated the guiding pipe is lifted, supported on

its hinged shaft, by pulling a wire, so that it will be moved away from its position in front of the water jet coming from the steering nozzle.

The branching solutions like that presented in the publication US 5299960 require substantial changes in the watercraft's structures. The construction presented in US 5516313 can be mounted without modification work, but a problem is to get the guiding pipe sufficiently tightly and firmly connected to the steering nozzle, particularly if the steering nozzle can turn in relation to the engine and the water jet generated by it. Generally there is a gap between the steering nozzle and the hull of the watercraft. During normal operation this gap does not present any problem, but when water is pumped, for instance at a pressure of seven atmospheres typically used by the fire brigade, the leakage from said gap can become considerable.

The prior art solutions mounted in watercraft provided with water jet engines are generally inconvenient to install. The required modification work of the engine structures or watercraft structures is often considerable and generally impossible to be made by the end user.

The object of the present invention is to provide a system, a method and a steering nozzle for a water jet engine which minimise the above-mentioned problems occurring in prior art. A particular object is to provide a water pump which uses a water jet engine as its power source and which operates better than the prior ones.

An object is also to provide a steering nozzle which is particularly well applicable in a water jet engine used as a water pump.

A particular object is to provide a water pump using a water jet engine as the power source, to which pump a hose or a corresponding connection can be connected tightly, firmly and easily.

The above mentioned disadvantages can be removed and the above mentioned objects achieved by the system, the method and the steering nozzle according to the invention, which are characterised in what is defined in the characterising parts of the independent claims presented below.

In all systems according to the invention a water jet engine is used as the water pump, the engine comprising a water channel intake port, a water channel, a turbine and a water channel outlet port, and a steering nozzle. The water channel refers to that channel, through which the water to be pumped passes in the water jet engine. The intake port is that opening, through which the water enters the water channel, and from the outlet port the water is discharged after the turbine.

The turbine refers to an apparatus located in the water channel for intensifying the water flow. In a water jet engine according to the invention the water flowing from the outlet port is directed to the steering nozzle, which steers this water jet into the desired direction, and/or which defines the shape of the water jet. The water jet is discharged from the steering nozzle through the jet port. A water jet engine according to the invention can be mounted as the power source of a watercraft, but the invention also comprises water jet engines intended to be only water pumps.

The steering nozzle can be arranged to be stationary regarding the engine and the direction of the water jet arranged to flow from its outlet port, whereby the whole engine must be turned in order to change the direction of the water jet. Such steering nozzles are found for instance in outboard engines which are fastened on the boat's transom. In boats provided with inboard engines, such as personal watercraft and in larger vessels the steering nozzle is generally turnable, whereby the travel direction of the vessel is controlled by turning the direction of the water jet by turning the steering nozzle. The steering nozzle can be mounted to turn also in the vertical direction. A so called trimmer of this type acts on the operating position of the vessel.

According to the invention there is mounted in connection with the water jet engine a system having a frame structure which is arranged to be substantially stationary regarding the water jet engine, the frame structure being fastened e. g. with bolts to the hull of the boat, vessel or outboard. At least one motion member is fastened to the frame structure, for instance a shaft arranged to be turnable on a hinge so that it can be moved in relation to the frame structure. A tube-like control member for directing the water jet is arranged in the motion member so that the control member can be located in front of the water jet generated by the engine, and so that the water can be directed for instance into a fire hose. By moving the motion member the control member of the water jet can be moved between at least two positions. These two positions are called the pumping position and the idle position. In the pumping position at least the first end of the control member is arranged in connection with the jet port of the steering nozzle in order to direct the

pumped water from the first end of the control member into the control member, through the control member and out through the other end of the control member.

At the other end there is typically a connector for connecting a hose, a pipe or another connecting member to the system, so that the water can be directed to the desired target. By moving the motion member, for instance by turning the control member on a hinged shaft 180 degrees vertically upwards or to one side, the control member of the water jet can be removed from the connection with the steering nozzle. In this idle position the control member is thus away from the position in front of the water jet, which enables an unhindered operation of the water jet engine. The system further comprises preferably members for keeping the control member and/or the motion member in their places, both during pumping and in the idle position. For this purpose for instance catches or rubber bands may be mounted in the system.

In a typical system according to the invention the steering nozzle is prevented from being pushed substantially into the control member in the pumping position.

This is arranged so that the opening of the first end of the control member is shaped so that at least one diameter of it is smaller than the second end of the steering nozzle. For instance a round control member and steering nozzle can be made to have equal sized cross-sections, whereby the ends of the control member and the steering nozzle are abutting in the pumping position, and the nozzle can not be pushed into the control member.

In all systems and methods according to the invention one of the most important advantages is that the control member of the water jet and the steering nozzle are kept in a tight contact, so that as large a share as possible of the water jet generated by the engine can be pumped to the desired place. A second most important advantage is the reliable operation, as it is easy to keep the control member tightly in its place connected to the steering nozzle, even at high pressures of the pumped water, and not even a side force can easily break such a connection. Further the system does not require moving parts, such as flaps or valves, which would be stressed by the flowing water. Another most important advantage of the invention is the easy installation of the system. If a boat or the like is provided with a water jet engine and a steering nozzle according to the invention, then no modifications are required in the boat or the like, but the system can be mounted directly on the transom of the boat, e. g. by bolts.

In an advantageous embodiment of the invention the frame structure of the inventive system is fastened between the hull of the watercraft and the steering nozzle. Such a construction requires particularly little installation work. The frame structure can be designed so that it is fastened to a boat or the like, for instance with the same bolts and in the same bolt bores as the steering nozzle. When the system is installed, then it is only necessary to remove the steering nozzle, to mount the system between the transom of the boat or the like and the steering nozzle, and to fasten the bolts.

In a typical system according to the invention at least the first end of the control member is arranged to extend from the jet port of the steering nozzle into the steering nozzle in the pumping position. A typical such control member, or at least its first end, has a smaller diameter than the jet port of the steering nozzle. The control member mounted inside the steering nozzle is easily kept tightly in its place.

In a particularly advantageous embodiment of the invention, in the pumping position, the first end of the water jet control member is arranged within the steering nozzle up to the outlet port of the water channel, and it is mounted in a substantially water tight connection with the outlet port of the water channel.

Thus, in the pumping position a control member of this kind is pushed through the whole steering nozzle until it abuts that component, in which the outlet port of the water channel is shaped. Generally the outlet port is in the transom of the boat. It is much easier than previously to arrange this connection between the control member and the outlet port of the water channel to be tight and stationary, when the end of the control member can be pressed e. g. against the transom of the boat.

In an advantageous embodiment of the invention the water jet control member comprises at least two tubular members which are arranged one at least partly within the other and one arranged to be movable in relation to the other, of which the first member is fixedly arranged in the motion members, and at least the first end of the second tubular member is arranged to be moved in the steering nozzle.

As a member of this type is moved from the idle position to the pumping position it is first placed against the steering nozzle, and then said second tubular member is moved in relation to the first, so that it at least partly is located within the steering nozzle. Advantageously the second tubular member has an outer diameter which is smaller than the inner diameter of the first tubular member, and it is

arranged within the first tubular member so that the second member can be moved within the first one. Without a telescopic construction it could be impossible in some situations to turn the longer control member into the pumping position, i. e. directly into the steering nozzle, for instance when the control member is very closely of the same size as the jet port. Now the control member can be pushed within the steering nozzle in the direction of the water jet, whereby the jet port and the control member can have diameters of almost the same size. In addition such a water jet control member is short when in the idle position, due to its telescopic construction, whereby it causes less troubles when the pumping is over, for instance when a personal watercraft is moving from one place to the next.

In the method according to the invention a water jet engine is used as a water pump, the engine comprising a water channel intake port, a turbine for intensifying the water flow in the water channel, and a water channel outlet port, as well as a steering nozzle for steering the water jet discharged from the outlet port. In the method the pumped water is directed from the steering nozzle's jet port into the first end of a tubular water jet control member arranged within the steering nozzle, through the control member and out through the second end of the control member, from where the water can be directed further e. g. into a fire hose or a hydraulic gun.

In connection with the steering nozzle according to the invention there are arranged motion members in order to move the jet port of the second end of the steering nozzle in the direction of the water jet and against it. Motion member refers to all kinds of members which can provide or which enable the second end of the steering nozzle to be moved in the mentioned manner. The direction of the water jet refers in this context to its general direction when it flows from the outlet port. Generally the water channel has a substantially straight last section before the outlet port, whereby the water continues its flow in this same direction, also when it is discharged through the outlet port. A steering nozzle according to the invention can be arranged so that it can move in said water jet direction as an entity, or the nozzle can be assembled of separately movable parts, whereby for instance only the end at the jet port of the nozzle can be moved in the direction of the water jet. Such a steering nozzle can for instance have a telescopic structure.

The inventive motion of the steering nozzle can be controlled for instance with a remote controlled hydraulic or electric motor. The steering nozzle can also have a passive movable structure, whereby the jet port's location will change in the

direction of the water jet when an external force acts on it, for instance when a connector or the like is pressed from behind against the steering nozzle, so that the connector or the like directs the water coming from the water jet engine, for instance into a fire hose. The connection between the steering nozzle and for instance the engine or watercraft can be supported by springs, so that when the external force stops acting on the steering nozzle, it will automatically return to its initial position.

In order to use a water jet engine as a water pump in a typical system according to the invention, in connection with the water jet engine there is a steering nozzle according to the invention which is movable in the direction of the water jet. In the idle position the steering nozzle is in its traditional operating position, for instance in a watercraft the jet port of the steering nozzle of the water jet engine is generally slightly behind the water channel's steering port when the craft is going straight. In the pumping position the steering nozzle, or at least its second end and the jet port at the second end, is compared to the idle position moved in the direction against the water jet, which flows through the outlet port. In addition the system has means for keeping the control member and/or the motion member in its place, both during pumping and in the idle position.

A steering nozzle according to the invention which is movable in the direction of the water jet, and a system comprising such a steering nozzle, can be realised in many different ways. The steering nozzle can be for instance arranged to be moved into the pumping position by pressing the water jet control member against the steering nozzle. Then the motion members of the steering nozzle may comprise a spring or the like which returns the steering nozzle into the idle position when the water jet control member is moved into the idle position. The inventive motion of the steering nozzle can also be realised mechanically. In the idle position the jet port of the steering nozzle can be located, in the direction of the water jet and in relation to the water channel's outlet port, either upstream or downstream from the port, or at the same level as the opening. It is essential that in the pumping position the jet port is displaced against the water jet's direction, in relation to the idle position. If the first end of the water jet control member, which is pressed against the steering nozzle from behind, and at the same time also the jet port of the steering nozzle, are arranged in the pumping position to be pressed even past the outlet port of the water channel, then the joint between the steering nozzle and the control member will be particularly tight and firm.

Present day steering nozzles are often funnel-shaped and resemble the frustum of a cone where the sectional plane of the tip forms the jet port of the steering nozzle.

The funnel-shaped steering nozzle according to the invention, which is movable in the direction of the water jet, is advantageously arranged so that in the pumping position the internal surface of the nozzle is pressed against the edges of the water channel's outlet port, and in this way it seals the gap between the steering nozzle and the outlet port. A steering nozzle according to the invention may also have a telescopic structure, for instance so that only the second end of the steering nozzle with the jet port is arranged to be movable. It is also possible that the different parts of the steering nozzle are arranged to move distances of different lengths.

One of the most important advantages of the invention comprising a jet port which is movable in the direction of the water jet is that a gap between the steering nozzle and the water channel can be sealed. Thus the pressure losses will be low and the pumping more efficient.

In a particularly advantageous embodiment according to the invention the whole steering nozzle is arranged to be movable in the direction of the water jet flowing from the outlet port and against it. Such a steering nozzle has a simple structure.

In a particularly advantageous embodiment according to the invention the steering nozzle or its end comprising the jet port is arranged to move so that in the pumping position the jet port of the steering nozzle is arranged at the level of the outlet port, in the direction of the water jet which is arranged to flow from the outlet port. Then the first end of the water jet control member is arranged in a substantially water tight connection with the outlet port of the water channel. If the outlet port is directly at the transom of the boat, then the end of the control member can be pressed against the transom of the boat, and the joint between the control member and the outlet port is ever more easier than before to be arranged tight and to be kept in its place.

In a particularly advantageous embodiment of the invention, in the pumping position the first end of the steering nozzle movable in the direction of the water jet is in a substantially water tight connection with a plane, which is substantially perpendicular to the direction of the water jet, such as the transom of the boat using the water jet engine as its source of propulsion power. A water tight

connection reduces water leaks past the jet port. In addition a construction of this kind is robust.

In a particularly advantageous embodiment of the invention, in the pumping position the first end of the steering nozzle of the water jet is arranged within the steering nozzle through the jet port of the steering nozzle movable in the direction of the water jet. This provides a particularly tight and reliable water passage from the engine to the control member. In such a system the structure of the steering nozzle and the control member can vary within the scope of the invention.

Below the invention is described in detail with reference to the enclosed figures, in which Figure 1 shows schematically and partly in cross-section a system according to the invention in the idle position; Figure 2 shows schematically and partly in cross-section the system of figure 1 in the pumping position; Figure 3 shows schematically and partly in cross-section another system according to the invention in the idle position; Figure 4 shows schematically and partly in cross-section the system of figure 3 in the pumping position; Figure 5 shows schematically in an elevational view the steering nozzle of the system according to figure 3 separated from the rest of the system; Figure 6 shows schematically and partly in cross-section a third system according to the invention in the idle position; and Figure 7 shows schematically and partly in cross-section the system of figure 6 in the pumping position.

Figures 1 and 2 show an advantageous system according to the invention for using a water jet engine 1 as a water pump. The water jet engine 1 comprises a water channel intake port (not shown in the figures), a water channel 2, a turbine 3 and a

water channel outlet port 4 as well as a steering nozzle 5 having a first end 22 and a second end 23. The turbine 3 of the water jet engine 1 generates or intensifies the flow of the pumped liquid, advantageously just water, in the water channel 2. The water brought into a strong flow passes along the water channel 2 to the outlet port 4 and from there through the first end 22 of the steering nozzle 5 fastened immediately in the vicinity of the outlet port 4 into the steering nozzle 5. At the second end 23 of the steering nozzle there is a jet port 6 for directing the flowing water out through the steering nozzle 5. By turning the steering nozzle 5 with the aid of the turning members 7a and 7b the direction of the water flow can be changed and controlled. The volume and the flow velocity of the flowing water can be controlled for instance by changing the rotational speed of the turbine 3, or by changing the size of the water channel's 2 intake port.

According to the figures 1 and 2 the frame structure 8 of the system according to the invention is arranged between the hull 9 of the watercraft and the steering nozzle 5. The frame structure 8 has adapters, with which the frame structure 8 is fastened to the hull 9 with the same fasteners as the steering nozzle 5. Then no separate fastening solutions are required, and no essential changes are required in the water jet engine 1 or the watercraft in order to install and operate the system. A system according to the invention can be mounted in the water jet engine 1 also by fastening the system to the hull 9 of the watercraft with the aid of separate adapters, such as bolt joints or press joints. A shaft 10 is connected to the system's frame structure 8 with the aid of a hinge 11. A tubular water jet control member 12 is fastened to the shaft 10, the member having a first end 13 and a second end 14.

The water jet control member 12 comprises two substantially tube-like members 15 and 16, of which the outer member part 15 is fastened substantially fixedly to the shaft 10, and within the outer member part 15 there is an inner member part 16, which is arranged to be movable regarding the outer member part 15. The control member 12 can comprise an actuator (not shown in the figures), with which the inner member part 16 can be moved within the outer member part 15.

At the second end 14 of the control member 12 there is a fastening fitting 17, with which a hose used e. g. for extinguishing fires can be fastened to the control member 12.

Figure 1 shows a system according to the invention in the idle position. Then the control member 12 is supported by the shaft 10 and removed from the path of the water jet flowing from the water jet engine 1. The control member 12 can be

secured in the idle position by separate fastening means, such as fastening hooks or rubber fasteners, whereby the control member 12 is kept in the desired position in a stable fashion. When the control member 12 is in the idle position, the water jet engine 1 can be used normally, for instance as the propulsion power source for a watercraft. In addition it is easy and to fasten auxiliary equipment, such as fire hoses, to the control member 12. In the idle position the steering nozzle 5 is in a position where it usually is when the watercraft is operated. The steering nozzle 5 and the wall 18 surrounding the outlet port 4 of the water channel 2 are not tightly connected in the idle position, but there is a gap 20 between them in order to make it possible to turn the steering nozzle 5 and thus to steer the watercraft.

Figure 2 shows a system according to the invention in the pumping position. In the pumping position the control member 12 is turned with the aid of the shaft 10, so that the first end 13 of the control member 12 is connected to the second end 23 of the steering nozzle 5. The control member 12 can be turned for instance manually or with the aid of a separate actuator.

When the system according to the invention in figures 1 and 2 is brought into the pumping position the outer member part 15 of the control member 12 is turned against the second end 23 of the steering nozzle, and the inner member part 16 is pushed into the steering nozzle 5 through the jet port 6. The inner member part 16 is advantageously pushed in a substantially water tight fashion against the wall 18 surrounding the outlet port 4 of the water channel 2. Then the water coming out through the water channel 2 or the water jet engine 1 is directed immediately from the first end 13 of the control member into the control member 12 and out through the second end 14, from where the water flow passes into an accessory (not shown in the figure) fastened to the control member 12, such as into a hose or a hydraulic gun. When the system is brought from the pumping position into the idle position, the inner member part 16 is moved away from the steering nozzle 5 and the shaft 10 is turned, so that the control member 12 returns to its upper position. Actuators, such as for instance spring member or a motor or other members, can be attached to the control member 12, so that these means perform the movements of the inner member part 16 in relation to the outer member part 15.

The figures 3 and 4 present another advantageous system according to the invention for using a water jet engine 1 as a water pump, and figure 5 shows the steering nozzle 5 presented in figures 3 and 4 when it is removed from the rest of

the system, and as seen from above. The system of the figures 3 and 4 corresponds to the system presented in figures 1 and 2 in other respects, but the control member 12 comprises one tubular part which is fixedly fastened to the shaft 10, and the steering nozzle 5 is arranged movable in the direction of the water jet.

In the system of figures 3 and 4 the steering nozzle 5 is fastened in the immediate vicinity of the outlet port 4 with the aid of moving members 19. With the aid of the loop-like fittings acting as the moving members 19 the steering nozzle 5 can be moved in the flow direction of the water flowing from the outlet port 4 and against it. As moving members 19 there may also be used for instance guides, axes, bars or other corresponding member.

Figure 3 illustrates a system according to the invention in the idle position, and figure 4 illustrates it in the pumping position. When the system according to the invention is brought into the pumping position the first end 13 of the control member 12 is first turned against the second end 23 of the steering nozzle. As the turning motion of the control member 12 is continued the steering nozzle 5 moves against the water flow, so that the internal side of the steering nozzle 5 is pressed in a substantially water-tight manner against the wall 18 surrounding the outlet port 4 of the water channel 2, whereby the gap 20 is closed. Then the water coming from the water channel 2 of the water jet engine 1 is directed immediately through the steering nozzle 5 and through the first end 13 of the control member into the control member 12, and out through the second end 14, from where the water flow passes into an accessory (not shown in the figure), such as a hose or a hydraulic gun, which is fastened to the control member 12. When the system is brought from the pumping position into the idle position the control member 12 is turned back into the upper position, and the steering nozzle 5 is returned into its original position. Actuators, such as for instance spring member or a motor or other members can be attached to the moving members 19, so that these members perform the movements of the steering nozzle 5 in the direction of the water flow.

Figures 6 and 7 present as an example a third system according to the invention for using a water jet engine 1 as a water pump. The application example illustrated in the figures 6 and 7 differs from that presented in the figures 3 and 4 regarding the construction of the steering nozzle 5, and thus regarding the operation of the system. When the system according to that shown in the figures 6 and 7 is brought into the pumping position the first end 13 of the control member 12 is first turned

against the second end 23 of the steering nozzle 5. As the turning motion of the control member 12 is continued the steering nozzle 5 moves against the water flow, so that the first end 13 of the control member 12 can be pressed in a substantially water-tight fashion against the wall 18 surrounding the outlet port 4 of the water channel 2. Then the water coming through the water channel 2 of the water jet engine 1 is directed immediately into the control member 12, from the first end 13 and out through the second end 14, from where the water flow passes into an accessory (not shown in the figure), such as a hose or a hydraulic gun, which is fastened to the fastener 17 of the second end 14 of the control member 12.

With the solution presented in figures 6 and 7 it is also possible to seal the gap between the first end 22 of the steering nozzle and the transom of the boat or some other plane 21. In figure 7 it is seen how the first end 22 of the steering nozzle in the pumping position is tightly pressed against the plane 21 of the frame structure 8 mounted in the watercraft 9, the plane being parallel to the transom of the boat.

The steering nozzle 5, which is arranged to be movable, can also be arranged to be compressable, for instance due to a telescopic structure of the steering nozzle 5, which does not necessarily require any moving members 19 to move the whole steering nozzle 5.

To a person skilled in the art it is obvious that the invention is not restricted only to the above presented examples, but the invention can be varied within the scope of the claims presented below. The steering nozzle, the method and the system according to the invention can be used also for underwater pumping of water, for instance on underwater construction sites for levelling sand with the water jet. The water jet can also generate suction in a suction pipe, with which it is for instance possible to draw away stones from an underwater blasting work site. The pumped water can be directed for instance to a hydraulic gun located in the same watercraft, or the pump can be used for watering or for car washing for instance at a summer house. The construction solutions of the system may also be different from those described in the examples. Advantageously the system comprises fasteners, such as hooks, catches or rubber loops, with which the control member with its shaft can be fastened both in the idle position and the pumping position.

The water pumped by the engine can be directed simultaneously for more than one purpose, a portion of the water jet generated by the engine can be used for instance

for propelling the watercraft during the pumping. The components of the system are advantageously made of plastics, aluminium or stainless steel. Plastics and aluminium are light-weight and they, as well as stainless steel, are very corrosion resistant.