| 摘要 |
A button bit is disclosed of the type that is rotatable in a predetermined direction of rotation (R) around a centre axis (C) and includes a number of spaced-apart peripheral buttons, which protrude forward from a front end surface to which an envelope surface connects having a rotationally symmetrical shape, the individual peripheral button being tilted partly in relation to the centre axis (C) of the drill bit, partly in the forward direction of rotation (R) in relation to the surface from which the button protrudes. The hole for the individual peripheral button mouths in a countersunk entering surface which is planar, ring-shaped and extends perpendicularly to the centre axis (C 1 ) of the hole. By tipping the button in the forward direction of rotation, the same will operate aggressively and efficiently. Also, the peripheral button may be mounted in accurate drilled apertures which are simple to provide, despite the complex space geometry predicament. |
