Cutting head having rotationally asymmetric coupling pin, tool shank and cutting tool
A cutting tool includes a cutting head and a tool shank, each having an axial abutment surface. One of the two includes a coupling pin, while the other includes a pin receptacle and a clamping through bore that opens out to the pin receptacle. The coupling pin has an engagement groove and the pin receptacle has an engagement ridge. The coupling pin is received into the pin receptacle. The cutting head and tool shank are releasably attached together by a fastening member that passes through the clamping through bore and acts on the coupling pin so that the engagement groove abuts the engagement ridge and the axial abutment surfaces on each part abut each other.
1 . A cutting tool ( 20 , 120 ), having a tool central axis (A) that defines opposite forward and rearward directions (D F , D R ), the cutting tool ( 20 , 120 ) including:
a cutting head ( 22 , 122 ) comprising:
a head peripheral surface ( 36 ) extending circumferentially about the tool central axis (A) and forming a boundary of a rearwardly facing first head end surface ( 34 a );
a head axial abutment surface ( 66 ) located on the first head end surface ( 34 a ), the head abutment surface ( 66 ) being planar and orthogonal to the head central axis (B); and
an insert pocket ( 27 );
a tool shank ( 24 , 124 ) comprising:
a shank peripheral surface ( 78 ) extending circumferentially about the tool central axis (A) and forming a boundary of a forwardly facing first shank end surface ( 76 a );
a shank axial abutment surface ( 104 ) located on the first shank end surface ( 76 a ); and
a coupling pin ( 38 ) projecting from one of the first head end surface ( 34 a ) and the first shank end surface ( 76 a ), the coupling pin ( 38 ) comprising:
a pin outer peripheral surface ( 44 ) extending about a pin central axis (D);
a pin vertical axis (VP) which is perpendicular to, and intersects, the pin central axis (D) to thereby define a pin vertical plane (PVP);
a pin engagement groove ( 52 ) recessed in the pin outer peripheral surface ( 44 ) and extending from a pin free end ( 41 ) towards a pin fixed end ( 40 ) along a groove longitudinal axis (G); and
a clamping recess ( 58 ) recessed in the pin outer peripheral surface ( 44 ) opposite the pin engagement groove ( 52 ) about the pin central axis (D);
a pin receptacle ( 80 ) recessed in the other of the first head end surface ( 34 a ) and the first shank end surface ( 76 a ), the pin receptacle ( 80 ) comprising:
a receptacle inner peripheral surface ( 86 ) extending about a receptacle central axis (E);
a receptacle vertical axis (VR) which is perpendicular to, and intersects, the receptacle central axis (E) to thereby define a receptacle vertical plane (RVP); and
a receptacle engagement ridge ( 90 ) protruding from the receptacle inner peripheral surface ( 86 ) and extending from a receptacle open end ( 82 ) towards a receptacle bottom end ( 84 ) along a ridge longitudinal axis (R); and
a clamping through bore ( 96 ) formed in whichever one of the head peripheral surface ( 36 ) and the shank peripheral surface ( 78 ) the pin receptacle ( 80 ) is recessed, and opening out to the pin receptacle ( 80 ) at a receptacle through bore opening ( 98 ) located opposite the receptacle engagement ridge ( 90 ) about the receptacle central axis (E), wherein:
the cutting tool ( 20 , 120 ) is adjustable between a released position and a locked position, and in the locked position:
the coupling pin ( 38 ) is received into the pin receptacle ( 80 ); and
a fastening member ( 28 ) passes through the clamping through bore ( 96 ) and acts on the clamping recess ( 58 ) of the coupling pin ( 38 ), so that:
the pin engagement groove ( 52 ) abuts the receptacle engagement ridge ( 90 );
the head axial abutment surface ( 66 ) abuts the shank axial abutment surface ( 104 ); and
the cutting head ( 22 , 122 ) and tool shank ( 24 , 124 ) are releasably attached together.
2 . The cutting tool ( 20 ), according to claim 1 , wherein:
the coupling pin ( 38 ) projects from the first head end surface ( 34 a );
the pin receptacle ( 80 ) is recessed in the first shank end surface ( 76 a ); and
the clamping through bore ( 96 ) is formed in the shank peripheral surface ( 78 ).
3 . The cutting tool ( 20 ), according to claim 1 , wherein:
the pin engagement groove ( 52 ) comprises a groove concavely curved portion ( 56 ) extending along the groove longitudinal axis (G);
the receptacle engagement ridge ( 90 ) comprises a ridge convexly curved portion ( 94 ) extending along the along the ridge longitudinal axis (R); and
in the locked position, the groove concavely curved portion ( 56 ) abuts the ridge convexly curved portion ( 94 ).
4 . The cutting tool ( 20 , 120 ), according to claim 1 , wherein:
the cutting tool ( 20 , 120 ) comprises a single centrally disposed coupling pin ( 38 ) and a single centrally disposed pin receptacle ( 80 ).
5 . The cutting tool ( 20 , 120 ), according to claim 1 , wherein:
the cutting tool ( 20 , 120 ) comprises exactly one fastening member ( 28 ) and exactly one clamping through bore ( 96 ) for securing the cutting head ( 22 , 122 ) to the tool shank ( 24 , 124 ); and
the coupling pin ( 38 ) comprises exactly one clamping recess ( 58 ).
6 . The cutting tool ( 20 , 120 ), according to claim 1 , wherein:
the clamping through bore ( 96 ) comprises an internal threaded portion ( 100 );
the fastening member ( 28 ) comprises an external threaded portion ( 108 ); and
in the locked position, the external threaded portion ( 108 ) is threadingly engaged with the internal threaded portion ( 100 ).
7 . The cutting tool ( 20 , 120 ), according to claim 1 , wherein:
the cutting tool ( 20 , 120 ) comprises a supplementary clamping screw ( 114 );
the cutting head ( 22 , 122 ) comprises a head clamping through bore ( 62 ) recessed in the second head end surface ( 34 b ) and opening out to the first head end surface ( 34 a ); and
the tool shank ( 24 , 124 ) comprises a shank clamping threaded bore ( 102 ) recessed in the first shank end surface ( 76 a ); and
in the locked position, the supplementary clamping screw ( 114 ) is located in the head clamping through bore ( 62 ) and threadingly engaged with the shank clamping threaded bore ( 102 ).
8 . The cutting tool ( 120 ), according to claim 1 , wherein:
the coupling pin ( 38 ) projects from the first shank end surface ( 76 a );
the pin receptacle ( 80 ) is recessed in the first head end surface ( 34 a ); and
the clamping through bore ( 96 ) is formed in the head peripheral surface ( 36 ).
9 . A cutting head ( 22 , 122 ), having a head central axis (B) that defines opposite forward and rearward directions (D F , D R ), the cutting head ( 22 , 122 ) comprising:
a head peripheral surface ( 36 ) extending circumferentially about the head central axis (B) and forming a boundary of a rearwardly facing first head end surface ( 34 a );
a head axial abutment surface ( 66 ) located on the first head end surface ( 34 a ), the head abutment surface ( 66 ) being planar and orthogonal to the head central axis (B);
an insert pocket ( 27 ); and
either:
a coupling pin ( 38 ) projecting from the first head end surface ( 34 a ), the coupling pin ( 38 ) comprising:
a pin outer peripheral surface ( 44 ) extending about a pin central axis (D);
a pin vertical axis (VP) which is perpendicular to, and intersects, the pin central axis (D) to thereby define a pin vertical plane (PVP);
a pin engagement groove ( 52 ) recessed in the pin outer peripheral surface ( 44 ) and extending from a pin free end ( 41 ) towards a pin fixed end ( 40 ) along a groove longitudinal axis (G); and
a clamping recess ( 58 ) recessed in the pin outer peripheral surface ( 44 ) opposite the pin engagement groove ( 52 ) about the pin central axis (D); or;
a pin receptacle ( 80 ) recessed the first head end surface ( 34 a ), the pin receptacle ( 80 ) comprising:
a receptacle inner peripheral surface ( 86 ) extending about a receptacle central axis (E);
a receptacle vertical axis (VR) which is perpendicular to, and intersects, the receptacle central axis (E) to thereby define a receptacle vertical plane (RVP); and
a receptacle engagement ridge ( 90 ) protruding from the receptacle inner peripheral surface ( 86 ) and extending from a receptacle open end ( 82 ) towards a receptacle bottom end ( 84 ) along a ridge longitudinal axis (R); and
a clamping through bore ( 96 ) recessed in the head peripheral surface ( 36 ) and opening out to the pin receptacle ( 80 ) at a receptacle through bore opening ( 98 ) located opposite the receptacle engagement ridge ( 90 ) about the receptacle central axis (E).
10 . The cutting head ( 22 ), according to claim 9 , wherein:
the coupling pin ( 38 ) projects from the first head end surface ( 34 a ).
11 . The cutting head ( 22 , 122 ), according to claim 10 , wherein:
the pin vertical plane (PVP) intersects the pin engagement groove ( 52 ); and
the pin engagement groove ( 52 ) exhibits mirror asymmetry about the pin vertical plane (PVP).
12 . The cutting head ( 22 , 122 ), according to claim 10 , wherein:
the pin engagement groove ( 52 ) comprises two opposing groove side surfaces ( 54 ) which slope inwardly in opposite widthwise directions of the pin engagement groove ( 52 ), so that they converge towards each other.
13 . The cutting head ( 22 , 122 ), according to claim 12 , wherein:
the two groove side surfaces ( 54 ) intersect each other.
14 . The cutting head ( 22 , 122 ), according to claim 12 , wherein:
the pin engagement groove ( 52 ) comprises a groove concavely curved portion ( 56 ) which extends along the groove longitudinal axis (G) and connects the two groove side surfaces ( 54 ).
15 . The cutting head ( 22 , 122 ), according to claim 14 , wherein:
the groove concavely curved portion ( 56 ) is defined by a groove concave radius (GR); and
the groove concave radius (GR) fulfils the condition: 2.8 mm≤GR≤3.6 mm.
16 . The cutting head ( 22 , 122 ), according to claim 10 , wherein:
the pin engagement groove ( 52 ) has a groove depth (GD); and
the groove depth (GD) fulfils the condition: 0.3 mm≤GD≤0.7 mm.
17 . The cutting head ( 22 , 122 ), according to claim 10 , wherein:
the pin engagement groove ( 52 ) has a groove width (GW); and
the groove width (GW) fulfils the condition: 5.0 mm≤GW≤5.84 mm.
18 . The cutting head ( 22 , 122 ), according to claim 10 , wherein:
the pin engagement groove ( 52 ) extends lengthwise along an entire axial extent of the coupling pin ( 38 ).
19 . The cutting head ( 22 , 122 ), according to claim 10 , wherein:
the groove longitudinal axis (G) is parallel to the pin central axis (D).
20 . The cutting head ( 22 , 122 ), according to claim 10 , further comprising:
a head coolant channel ( 70 ) having a head coolant channel inlet ( 72 i ) and a head coolant channel outlet ( 720 ); wherein:
the coupling pin ( 38 ) comprises a pin rear surface ( 42 ) bounded by the pin outer peripheral surface ( 44 ); and
the head coolant channel inlet ( 72 i ) is located on the pin rear surface ( 42 ).
21 . The cutting head ( 22 , 122 ), according to claim 20 , wherein:
the pin engagement groove ( 52 ) extends to the pin rear surface ( 41 ).
22 . The cutting head ( 22 , 122 ), according to claim 10 , further comprising:
a second head end surface ( 34 b ) opposite the first head end surface ( 34 a ); and
a head clamping through bore ( 62 ) recessed in the second head end surface ( 34 b ) and opening out to the first head end surface ( 34 a ).
23 . The cutting head ( 22 , 122 ), according to claim 10 , wherein:
the pin outer peripheral surface ( 44 ) comprises opposing pin upper and lower surfaces ( 46 , 48 ) and two opposing pin side surfaces ( 50 ) which connect the pin upper and lower surfaces ( 46 , 48 );
the clamping recess ( 58 ) is located on the pin upper surface ( 46 ); and
the clamping recess ( 58 ) comprises a clamping recess abutment surface ( 60 ) which slopes towards a pin median plane (MP) containing the pin central axis (D) and extending through the two opposing pin side surfaces ( 50 ), in a direction towards the first head end surface ( 34 a ).
24 . The cutting head ( 22 , 122 ), according to claim 23 , wherein:
the insert pocket ( 27 ) comprises a pocket seat surface ( 27 a ) configured to seat a cutting insert ( 26 ), the pocket seat surface ( 27 a ) facing in the same direction as the pin upper surface ( 46 ).