Cutter head for dredging ground, cutter suction dredger provided with such a cutter head and use of the cutter head for dredging ground

Abstract

A cutter head according to the invention is particularly suitable for breaking relatively hard ground, is self-sharpening and has an extended service life.

1 - 13 . (canceled) 
     
     
         14 . A cutter head ( 10 ) for dredging ground under the water surface, comprising a revolving body ( 11 ) which is rotatable around a central axis and which is formed by a base ring ( 13 ) and a hub ( 14 ) placed at a distance therefrom, between which extend a number of support arms ( 15 ) provided with cutting tools ( 20 ), between which support arms ( 15 ) passage openings ( 16 ) are present for discharge of the dredged ground, wherein the cutter head comprises at least  50  cutting tools, which cutting tools ( 20 ) are axisymmetrical at least at their free outer end. 
     
     
         15 . The cutter head ( 10 ) of  claim 14 , wherein the cutting tools ( 20 ) are arranged on the support arms ( 15 ) such that they can be rotated freely around their axis of rotation symmetry. 
     
     
         16 . The cutter head ( 10 ) of  claim 14 , wherein the cutting tools ( 20 ) are conical. 
     
     
         17 . The cutter head ( 10 ) of  claim 14 , wherein the top part of the conical cutting tools ( 20 ) has at the free outer end a radius of curvature of a maximum of 50 mm. 
     
     
         18 . The cutter head ( 10 ) of  claim 14 , wherein the cutter head ( 10 ) comprises at least  10  support arms ( 15 ). 
     
     
         19 . The cutter head ( 10 ) of  claim 14 , wherein that a support arm ( 15 ) comprises at least  20  cutting tools ( 20 ). 
     
     
         20 . The cutter head ( 10 ) of  claim 14 , wherein the cutting tools ( 20 ) are oriented relative to the support arms ( 15 ) such that during rotation of the cutter head through the ground they strike substantially perpendicularly of the ground surface. 
     
     
         21 . The cutter head ( 10 ) of  claim 14 , wherein a support arm ( 15 ) comprises a first series of cutting tools ( 20 ) on a leading part ( 15   a ) thereof as seen in the direction of rotation of the cutter head ( 10 ), and that the support arm ( 15 ) comprises a second series of cutting tools ( 20 ) on a part ( 15   b ) facing away from the central axis. 
     
     
         22 . The cutter head ( 10 ) of  claim 21 , wherein, on the same support arm ( 15 ), the cutting tools ( 20 ) of the first series are disposed offset relative to the cutting tools ( 20 ) of the second series. 
     
     
         23 . The cutter head ( 10 ) of  claim 14 , wherein the cutting tools ( 20 ) are connected to the support arms ( 15 ) via coupling means ( 17 ). 
     
     
         24 . The cutter head ( 10 ) of  claim 23 , wherein the support arms ( 15 ) of the cutter head are provided with guides on which the coupling means ( 17 ) and/or the cutting tools ( 20 ) are displaceably mounted. 
     
     
         25 . Use of a cutter head ( 10 ) for dredging an underwater ground with an Unconfined Compressive Strength (UCS) of at least 50 MPa, with said cutter head comprising a revolving body ( 11 ) which is rotatable around a central axis and which is formed by a base ring ( 13 ) and a hub ( 14 ) placed at a distance therefrom, between which extend a number of support arms ( 15 ) provided with cutting tools ( 20 ), between which support arms ( 15 ) passage openings ( 16 ) are present for discharge of the dredged ground, wherein the cutter head comprises at least 50 cutting tools, which cutting tools ( 20 ) are axisymmetrical at least at their free outer end. 
     
     
         26 . The use of  claim 25  wherein the Unconfined Compressive Strength (UCS) is at least 60 MPa. 
     
     
         27 . The use of  claim 25  wherein the Unconfined Compressive Strength (UCS) is at least 80 MPa. 
     
     
         28 . A cutter suction dredger ( 1 ) provided with a cutter head ( 10 ) comprising a revolving body ( 11 ) which is rotatable around a central axis and which is formed by a base ring ( 13 ) and a hub ( 14 ) placed at a distance therefrom, between which extend a number of support arms ( 15 ) provided with cutting tools ( 20 ), between which support arms ( 15 ) passage openings ( 16 ) are present for discharge of the dredged ground, wherein the cutter head comprises at least 50 cutting tools, which cutting tools ( 20 ) are axisymmetrical at least at their free outer end.