Method and apparatus for correcting tool lengths and tool radii, particularly for numerically controlled machines equipped with position or path measuring systems by means of nominal-actual value comparison

摘要

A method of correcting tool lengths and tool radii, particularly for numerically controlled machines equipped with position or path measuring systems by means of a nominal-actual value comparison up to a length and radii with the actual values which comprises, comparing the length and radius of the tool with an actual value by means of the position or path measuring system with which the machine is equipped and which are associated with the axes of motion, storing the difference of the values with the correct sign in a correction memory of the numerical control as a tool length or radius correction, and wherein, the nominal actual value comparison is effected in the zero position or at the zero passage of an analog of a digital transmitter which is disposed so that its zero or zero passage position in the Z-axis and the X-axis corresponds to constant spacing from the machine (a+b). The device comprises a feeler housing which is mounted on mounting means of the machine adjacent the tool holder spindle and which includes a first feeler pin mounted in the feeler housing extending along the Z-axis and having a first switching portion and a second feeler pin extending along the X-axis perpendicular to the first feeler pin and spaced in height from said first feeler pin with gear means interconnecting said first and second feeler pins for moving one in response to movement of the other in respect to its associated axis. At least one limit tracer is disposed in the Z-axis and at least one inductive transmitter is disposed in the X- axis and stop means are disposed in said housing. Spring means urge the first and second feeler pins outwardly to apply against the stop means in the housing. Each limit tracer in the Z-axis is switchable by an associated switching portion of the feeler pin and an inductive transmitter extends parallel to the axis of the second feeler pin and is movable in the X- axis and disposed relative to the second feeler pin so as to be switched by a switching member portion thereof.