Patent ID: 6343900
Filing Date: 2002-02-05
Classification: B23Q,G05B,G05D,Y10S,Y10T

Abstract:
Pneumatic machine tool, comprising:a driving shaft (14) driven in rotation by pneumatic drive means (12), a driven tool-carrier shaft (16), a gear mechanism (18) disposed between the driving shaft (14) and the driven shaft (16) to drive the driven shaft, a set of sensors (22) for measuring operating parameters of the machine tool, and a central control unit (20) in which are stored algorithms for controlling machining as a function of data received from the sensors (22), the gear mechanism including means (24, 26, 28, 30, 36) for changing the gear ratio under the control of the central unit (20), the gear mechanism including primary and secondary sets (24, 26) of toothed wheels with different demultiplication ratios, each adapted to rotate freely relative to the driving shaft (14), the speed changing means including a positive clutch (28, 56) constrained to rotate with the driving shaft (14) and axially mobile relative thereto under the control of a pneumatic control unit (30) controlled by the central unit (20), between a first end position, in which the positive clutch is engaged with the primary set of toothed wheels so that the driving shaft drives the driven shaft at a first gear ratio, and a second end position, in which the positive clutch is engaged with the secondary set of toothed wheels so that the driving shaft drives the driven shaft at a second gear ratio.