| 摘要 |
An arrangement for driving a rotary tool (17) is provided in which the tool shank (18) is engaged and frictionally driven by the engagement of three or more drive rollers (14, 15, 16). Axial movement of the tool (17) is accomplished by tilting the axes of the rollers (14, 15, 16) as permitted by flexible portions (84) of the shafts (78) which drive the rollers (14, 15, 16). The tool (17) is released by moving one roller (16) away from the other two (14, 15). A pressure foot (115) is provided at the bottom of the assembly reciprocated by a cam arrangement (139) to engage the workpiece (13) when the tool (17) is in operation. A position pick-off (103, 104) senses the axial position of the tool (17) so that the tilt angle of the rollers (14, 15, 16) can be controlled. |
