The present invention relates to an auger head according to the preamble of claim 1. The invention also relates to a floating body, for example a ship comprising the auger head according to the invention.

It is known in the art to remove material from a water bottom by means of an auger head. An auger head is a cylindrical body with a longitudinal axis, being the rotation axis of the cylindri cal body. At the body's outer surface a helical screw part is pro vided, such that upon rotation of the body along a water bottom material is transported from ends of said body towards an interme diate portion. Material is then removed from said intermediate portion by means of a suction tube positioned at some distance from the auger head.

Such known auger head provides the disadvantage that only a small part of the material is actually removed from the water bot tom. A large part of said material is swirled up by the rotary ac tion of the auger head missing the entrance of the suction tube.

Another disadvantage of this known auger head is that it is a complex apparatus with a limited effectiveness.

The invention aims at providing an improved auger head of the kind mentioned in the preamble.

The invention further aims at providing an auger head that provides a better removal of material from the water bottom.

The invention also aims at providing an improved and easier to use auger head than an auger head according to the state of the art .

So as to obtain at least one of the above mentioned aims, the invention provides an auger head as mentioned in claim 1. This au ger head has the advantage that removal of material from the water bottom is done securely, removing substantially all material that has been transported to the intermediate portion of the auger head.

It has also shown that the auger head according to the pre- sent invention can be rotated at a higher rotational speed than known auger heads. Even at higher rotational speeds, no swirling up of material is obtained and thus no material is left at the wa ter bottom. Such synergistic effect is a surprising and advanta geous effect, since less effort is required to remove said materi al. Also, due to the higher rotational speed, the force impact of the auger head against the water bottom is much higher providing an even more improved effectiveness.

The invention therefore relates to an auger head for removing material from a water bottom, comprising a cylindrically shaped body for performing a rotary movement along the water bottom, said cylindrical body comprising a helically wound screw on its outer surface, said helically wound screw is embodied in at least two part form, a first screw part for transporting said material from a first end of said cylinder to an intermediate portion of said cylinder and a second screw part for transporting said material from a second end of said cylinder to said intermediate portion of said cylinder upon performing the rotary movement along the water bottom in one direction, characterized in that the cylindrical body comprises an intermediate opening in its outer wall near said intermediate portion for removing said material through said cy lindrical body and a discharge opening at an end surface for re moving said material from the cylindrical body. The present auger head ensures an excellent removal of material from the water bot tom, since the material is in a first step transported by means of the helical screw at the outside of the cylindrical body to an in termediate position thereof, usually but not necessarily to the center portion, and in a second but substantially continuous step the material enters the inside of the cylindrical body through said opening in the cylinder's outer wall, such that the material can be removed through said cylindrical body and out of the cylin drical body through the discharge opening at an end surface of the cylinder .

As a matter of fact, reference is made to NL8403586A relating to an auger head with dentations on its outer surface. The appa ratus is designed for making a trench in a water bottom for laying pipelines. A few dentations at a center portion of the auger head are provided with passages through the inside of the auger head. However, upon rotation, series of adjacent dentations push materi al to respective outer ends of the auger head. Collection of mate rial from a substantial length of the auger head through the in side of the auger head therefore is not possible and envisaged.

WO 03/106255 relates to an apparatus for removing floating debris from a water surface, like lakes and rivers. It is not em bodied for placing on a water bottom for removing solid material . There is no cylinder with an opening at its surface to displace material from the outside to the inside of said cylinder. Nor is there a discharge opening at an end surface for removing solid ma terial from the inside of the cylinder.

Both publications therefore do not relate to the problem of the present invention, nor do they provide or hint to a solution in accordance with the present invention.

So as to obtain an even more targeted removal of said materi al, it is preferred that the auger head comprises a discharge tube connected to the discharge opening at the end surface of said cy lindrical body for transporting said material to a remote loca tion. The advantage of the present embodiment is that the dis charge tube is directly connected to the hollow inside of the cy lindrical body collecting said material. There is no open space between the discharge opening of the cylinder and the entrance opening of such discharge tube. Thus, no foreign material from around the end, i.e. the entrance opening, of the discharge tube will enter the discharge tube.

It is especially preferred that the auger head comprises a pump for actively removing and transporting said material. Since the pump is actively coupled to the intermediate opening in the cylinder, it will apply a vacuum action at said intermediate open ing ensuring a continuous and effective removal of said material through said intermediate opening after said material has been transported towards the intermediate opening by means of the screw parts at the cylinder's outer surface.

So as to ensure a complete removal of material from the in side of the cylinder towards and into the discharge tube, said cy lindrical body may optionally have an internal screw for internal- ly transporting material from said intermediate opening near said intermediate portion towards a discharge opening at an end of said cylindrical body, i.e. towards the discharge tube.

As a result, preference is given to an auger head wherein a pump is connected to said discharge opening for removing said ma terial from said cylindrical body, optionally with intermediate placement of a transport line such as a pipeline, a tube or a hose. Such embodiment is able to efficiently and completely trans porting the material towards a remote location.

When the water bottom comprises solid material, it is pre ferred to grind or cut said material into smaller pieces. It then is preferred for the cylindrical body to be provided with teeth at its outer surface for cutting said water bottom.

Said cutting or grinding action is performed optimally, when the said teeth are connected to said helically wound screws, since in such embodiment the teeth with interact most efficiently with the water bottom.

An even most efficient action is obtained when said teeth are connected to the top part of said helically wound screws.

An easily applicable embodiment is obtained when said cylin drical body is rotatably coupled to a frame part at its two longi tudinal ends. Such embodiment provides a strong and stable appa ratus, easily withstanding forces that are encountered at water bottoms, especially water bottoms comprising large pieces of mate rial like rocks and stones, but pieces of organic material as well .

When using an auger head according to the invention, a rota tion device, also referred to as rotator, must be used for provid ing a rotary motion to the auger head. As a skilled person knows, the auger head has a cylindrical body with a longitudinal axis, said body rotating along said longitudinal axis. The rotation de vice preferably is a motor, for example an electric or hydraulic motor. Said rotation device directly interacts with said cylindri cal body. Preferably, providing a compact embodiment, the inven tion relates to an auger head wherein at a first longitudinal end a rotator is provided for inducing a rotatable motion to said cyl inder with respect to the frame part and at a second longitudinal end the discharge tube is connected for transporting said material from said cylindrical body to a remote location.

It is especially preferred that at least one of said rotator and said discharge tube is rigidly connected to said frame. For, such adds to the rigidity and strength of the complete construc tion of auger head and frame, including the rotator and tube con nection .

According to a further embodiment, the invention relates to an auger head as mentioned above, operable from a ship.

Finally, the invention also relates to a ship, comprising an auger head according to the present invention, comprising a frame to which said auger head is rotatably connected.

Hereafter, the invention will be further described by means of a drawing. The drawing shows in:

Fig. 1 a perspective view of an auger head according to the invention,

Fig. 2 a front view of an auger head according to the inven tion,

Fig. 3 a sectional view of the auger head according to Fig.

2.

The same and similar parts and features have been denoted by the same reference numerals in the figures. However, for ease of understanding the figures, not all parts that are required for a practical embodiment have been shown in the figures.

Fig. 1 shows an auger head 1, comprising a substantially cy lindrical body 2 with screw parts 3, 4 on its outer surface 5. The screw part 3 is wound oppositely with respect to screw part 4, such that upon rotation of the auger head along its longitudinal axis 6 (as shown in Fig. 2) in a suitable direction, material caught in between two neighboring screw wall parts 7, 8 (see espe cially Fig. 2) is transferred to an intermediate portion 9 of the auger head 1. Substantially all material caught in between two neighboring screw part walls from between a first end 10 and a second end 11 of the auger head will be transferred towards said intermediate portion 9.

In the embodiment shown in the figures, the auger head 1 com prises a single intermediate portion, since two oppositely thread- ed screw parts are provided at the auger head's surface. Optional ly, four, six, eight or any other even number of screw parts may be applied, yielding two, three, four et cetera intermediate por tions, respectively. The advantage of an even number of screw parts is that there are always two screw parts working together, moving material towards an opening at a common intermediate por tion in between said two screw parts.

In addition, a single pitch, a double pitch or even a triple or quadruple pitch may be applied. It is preferred that an opening is provided in the intermediate portion at the end of each pitch so as to obtain an optimum removal of material through said open ing at the end of each of said pitches. The drawings show an em bodiment with a double pitch and two screw parts.

Near the intermediate portion 9 an intermediate opening 12 is made in the body' s surface, yielding entrance to the body' s hollow inside. As a result, material that is transferred towards said in termediate opening 12 will be transferred into the body's hollow inside. At the first end 10 a discharge opening 13 is provided for removing said material from the body's hollow inside.

A discharge tube 14 may be connected to the said discharge opening 13 for transporting the material to a remote location.

Fig. 2 shows a front view of the auger head 1. The longitudi nal axis 6 is shown in this figure.

Fig. 3 finally shows a sectional view of the auger head 1 ac cording to the present invention. An optional screw 15 is provided in the body' s hollow inside, assisting in transporting material towards end 10, after it has entered the auger head 1 through said intermediate opening 12. This screw 15 prevents lagging of materi al inside the auger head 1. As a matter of fact, since the cylin drical body undergoes a rotational movement with respect to a wa ter bottom (or a like surface from which material has to be re moved) , the screw 15 may be static, in that no rotational movement is induced on said screw with respect to said water bottom.

At second end 11 a rotator 16 is provided for rotating the auger head 1 along its longitudinal axis 6. So as to be able to induce said movement, the rotator is coupled to a frame (not shown) that has a static position with respect to a water bottom or the like, as indicated above. The frame is preferably connected to a floating device when removing material from a water bottom. Most preferably, the frame is rotatably connected at both ends 10, 11 of the auger head 1.

The screw parts 3, 4 have a top part 17 at a position away from the body's surface 5. At said top part 17, cutting teeth 18 are provided for cutting and destroying material at the water bot tom .

The invention is not limited to the embodiments as mentioned above and as shown in the drawings. The invention is limited by the claims only.

The invention also relates to all combinations of features described here independently of each other.