| 主权项 |
1. A rotary cutting tool (20) comprising:
a cutting head (22) having a head central axis (A) defining a forward to rearward direction (DF, DR) and about which the cutting head (22) is rotatable in a rotational direction (R), the cutting head (22) comprising a forward end forming a cutting portion (28) and a rearward end forming a head coupling portion (30); the cutting portion (28) comprising:
a head rear surface (34), defining a boundary between the cutting portion (28) and the head coupling portion (30);a head rear abutment surface (38), located on the head rear surface (34);two cutting arms (42) extending radially with respect to the head central axis (A), each comprising a driven surface (50); and the head coupling portion (30) comprising a head coupling pin (60), protruding rearwardly from the head rear surface (34) along the head central axis (A), the head coupling pin (60) comprising:
a pin rear surface (62) spaced apart from the head rear surface (34) and a pin peripheral surface (64) extending therebetween;a guiding recess (66), recessed in the pin peripheral surface (64), opening out to the pin rear surface (62), and comprising a guiding surface (68) extending in a forward axial direction from the pin rear surface (62) towards the cutting portion (28); anda fastening recess (70), recessed in the pin peripheral surface (64), and comprising a lower inclined surface (73c) which is radially outwardly sloped relative to the head central axis (A), in the rearward direction (DR) of the cutting head (22); wherein
at least a portion of the lower inclined surface (73c) axially overlaps an overlapping region (74) of the guiding surface (68), said portion comprising a fastening surface (72a) that is angularly closer to said overlapping region (74) in the direction opposite the rotational direction (R) than in the rotational direction (R); and a tool holder (24), having a holder longitudinal axis (D), extending in the forward to rearward direction (DF, DR) and about which the tool holder (24) is rotatable in the rotational direction (R), the tool holder (24) comprising:
a holder peripheral surface (78) extending circumferentially along the holder longitudinal axis (D) and forming a boundary of a holder base surface (80) at a forward end of the tool holder (24);two circumferentially spaced apart driving members (84) extending forwardly from the holder base surface (80);a holder coupling hole (96) recessed in the holder base surface (80) and extending along the holder longitudinal axis (D) in the rearward direction (DR); anda holder through bore (102) extending along a holder through bore axis (B) from the holder coupling hole (96) to the holder peripheral surface (78); and an elastic fastening assembly (26, 126) releasably engaged to the tool holder (24) at the holder through bore (102), and having a protruding portion (122) protruding into the holder coupling hole (96); wherein
the rotary cutting tool (20) is adjustable between a guided position and a fastened position, wherein:in the guided position:
the head coupling pin (60) is located in the holder coupling hole (96); andthe protruding portion (122) is located in the guiding recess (66); andin the fastened position:
the cutting head (22) is releasably attached to the tool holder (24) by the elastic fastening assembly (26, 126);the head coupling pin (60) is located in the holder coupling hole (96);each cutting arm (42) is in contact with a respective driving member (84); and the elastic fastening assembly (26, 126) elastically engages the fastening surface (72a). |
