Fixing arrangement

Abstract

A fixing arrangement for holding a cutting tooth on a cutter. The cutting tooth has a tool head and a shank. The shank is accommodated in a shank-receiving element of the cutter or a holder connected to the cutter. One or several bearing surfaces of the cutting tooth each lies on support surfaces of the cutter. The cutting tooth can be supported in a stable and reliable manner by inclining the support surfaces and the bearing surfaces in a peripheral direction and by providing the cutter with a shoulder which is arranged in the direction of the cutter in an offset position relative to the bearing surfaces, the shoulder being associated with the cutting tooth at a distance.

1 . A securing arrangement for retaining a cutting tooth ( 30 ) on a drill bit ( 10 ), wherein the cutting tooth ( 30 ) includes a tool head ( 31 ) and a shaft ( 32 ), the shaft ( 32 ) is accommodated in a shaft receiver ( 22 ) of one of the drill bit ( 10 ) and a holder connected to the drill bit ( 10 ), and the cutting tooth ( 30 ) rests on support faces ( 24 ) of the drill bit ( 10 ) with at least one contact face ( 39 . 1 ), the securing arrangement comprising: the support faces ( 24 ) and the contact faces ( 39 . 1 ) inclined in a circumferential direction, the drill bit ( 10 ) having a shoulder ( 27 ) offset relative to the at least one contact face ( 39 . 1 ) in a direction of an axis of the drill bit ( 10 ) and associated with and spaced from the cutting tooth ( 30 ).  
   
   
       2 . The securing arrangement according to  claim 1 , wherein the shaft receiver ( 22 ) is admitted at least partially into a shoulder face formed by the shoulder ( 27 ) and faces the cutting tooth ( 30 ).  
   
   
       3 . The securing arrangement according to  claim 2 , wherein the drill bit ( 10 ) has two of the contact faces ( 39 . 1 ) for each cutting tooth ( 30 ), and the two contact faces ( 39 . 1 ) are opposite one another.  
   
   
       4 . The securing arrangement according to  claim 3 , wherein the cutting tooth ( 30 ) has a threaded portion ( 33 ), mounted on the shaft ( 32 ), a nut ( 34 ) is screw-connectable to the threaded portion ( 33 ), and the cutting tooth ( 30 ) is pressed onto the support faces ( 24 ) via the contact faces ( 39 . 1 ) in a pre-tensioned manner by the nut ( 34 ).  
   
   
       5 . The securing arrangement according to  claim 4 , wherein at least over a portion of a longitudinal region extending in the direction of the axis of the drill bit, the shaft ( 32 ) of the cutting tooth ( 30 ) is circumferentially surrounded by the shaft receiver ( 22 ).  
   
   
       6 . The securing arrangement according to  claim 5 , wherein the shaft ( 32 ) of the cutting tooth ( 30 ) includes at least one calibrating receiver ( 32 . 1 ) setback relative to an inner wall of the shaft receiver ( 22 ).  
   
   
       7 . The securing arrangement according to  claim 6 , wherein that the shaft ( 32 ) of the cutting tooth ( 30 ) is tapered at least over a portion of a longitudinal extension in a direction towards a free end and the shaft receiver ( 22 ) is tapered at least in a regional manner, and an outside cross-section of the shaft ( 32 ) is smaller than an inside cross-section of the shaft receiver ( 22 ).  
   
   
       8 . The securing arrangement according to  claim 7 , wherein the tool head ( 31 ) of the cutting tooth ( 30 ) includes at least one radial ( 38 . 1 ) near a region directed radially inwards.  
   
   
       9 . The securing arrangement according to  claim 8 , wherein the tool head ( 31 ) is closed at circumferential end regions with triangular convexly curved shaped faces ( 36 ).  
   
   
       10 . The securing arrangement according to  claim 9 , wherein the tool head ( 31 ) has at least one element ( 39 . 3 ) of hard material near a second region directed radially outwards.  
   
   
       11 . The securing arrangement according to  claim 10 , the at least one hard material element ( 39 . 3 ) is admitted into a web ( 37 . 2 ), disposed near the cutting tooth ( 30 ) lying radially outwards and extending in the direction of the axis of the drill bit and protruding above a base part ( 39 ) of the cutting tooth ( 30 ), and the hard material elements ( 39 . 3 ) protrude in a regional manner radially above the web ( 39 . 2 ).  
   
   
       12 . The securing arrangement according to  claim 11 , wherein remote from the shaft ( 32 ) the tool head ( 31 ) of the cutting tooth ( 30 ) has a top face ( 31 . 1 ) into which a hard material insert is inserted.  
   
   
       13 . The securing arrangement according to  claim 1 , wherein the drill bit ( 10 ) has two of the contact faces ( 39 . 1 ) for each cutting tooth ( 30 ), and the two contact faces ( 39 . 1 ) are opposite one another.  
   
   
       14 . The securing according to  claim 1 , wherein the cutting tooth ( 30 ) has a threaded portion ( 33 ) mounted on the shaft ( 32 ), a nut ( 34 ) is screw-connectable to the threaded portion ( 33 ), and the cutting tooth ( 30 ) is pressed onto the support faces ( 24 ) via the contact faces ( 39 . 1 ) in a pre-tensioned manner by the nut ( 34 ).  
   
   
       15 . The securing arrangement according to  claim 1 , wherein at least over a portion of a longitudinal region extending in the direction of the axis of the drill bit, the shaft ( 32 ) of the cutting tooth ( 30 ) is circumferentially surrounded by the shaft receiver ( 22 ).  
   
   
       16 . The securing arrangement according to  claim 15 , wherein the shaft ( 32 ) of the cutting tooth ( 30 ) includes at least one calibrating receiver ( 32 . 1 ) set back relative to an inner wall of the shaft receiver ( 22 ).  
   
   
       17 . The securing arrangement according to  claim 1 , wherein the shaft ( 32 ) of the cutting tooth ( 30 ) is tapered at least over a portion of a longitudinal extension in a direction towards a free end and the shaft receiver ( 22 ) is tapered at least in a regional manner, and an outside cross-section of the shaft ( 32 ) is smaller than an inside cross-section of the shaft receiver ( 22 ).  
   
   
       18 . The securing arrangement according to  claim 1 , wherein the tool head ( 31 ) of the cutting tooth ( 30 ) includes at least one radial ( 38 . 1 ) near a region directed radially inwards.  
   
   
       19 . The securing arrangement according to  claim 1 , wherein the tool head ( 31 ) is closed at circumferential end regions with triangular convexly curved shaped faces ( 36 ).  
   
   
       20 . The securing arrangement according to  claim 1 , wherein the tool head ( 31 ) has at least one element ( 39 . 3 ) of hard material near a second region directed radially outwards.  
   
   
       21 . The securing arrangement according to  claim 20 , the at least one hard material element ( 39 . 3 ) is admitted into a web ( 37 . 2 ) disposed near the cutting tooth ( 30 ) lying radially outwards and extending in the direction of the axis of the drill bit and protruding above a base part ( 39 ) of the cutting tooth ( 30 ), and the hard material elements ( 39 . 3 ) protrude in a regional manner radially above the web ( 39 . 2 ).  
   
   
       22 . The securing arrangement according to  claim 1 , wherein remote from the shaft ( 32 ) the tool head ( 31 ) of the cutting tooth ( 30 ) has a top face ( 31 . 1 ) into which a hard material insert is inserted.