Multi-functional measurement system

Monitoring apparatus for a machine for manufacturing bevel and hypoid gears, said machine being computer controlled and having a tool support with a spindle mounted in its front face for rotatably holding a tool for shaping teeth on a workpiece rotatably held in a work spindle mounted in the front face of a work support, said work support also having a side face and both said supports being movable relative to each other along a minimum number of operational axes, namely, three mutually orthogonal rectilinear axes and one pivot axis, said machine also having a plurality of encoder means associated with machine drive means for moving said supports, said encoder means providing respective measurement signals indicative of the positions of said supports relative to each other;

• said monitoring apparatus comprising:
• contact probe means, mounted on said tool support and movable from a withdrawn position to an extended position in which a sensitive tip associated with said contact probe means projects beyond the front face of said tool support, said contact probe means providing a contact trigger signal whenever the surface of said tip contacts another surface;
• a plurality of locating points positioned in predetermined locations on the side and front faces of said work support and on said work spindle;
• sets of predetermined position signals corresponding to the relative location of each of said locating points when said tool and work columns are in each of a plurality of predetermined relative orientations;
• and
• sets of instantaneous position signals from said encoders indicative of the relative location of said tool and work supports in respect to said axes whenever trigger signals are provided by said contact probe means upon contact with respective ones of said locating points;
• said computer being programmable for
• comparing sets of said instantaneous and predetermined position signals for each of said plurality of orientations;
• generating error signals based upon the difference between said respective signal sets;
• and
• controlling the operation of said machine drive means for positioning said tool and work supports in accordance with said error signals.

A method for measuring the tooth flanks of a gear-shaped workpiece rotatably mounted in the work spindle of a computer controlled machine having a tool support, said machine also having encoder means associated with drive means for rotating said spindle, said encoder means providing measurement signals indicative of the angular position of said spindle, said method comprising the steps of

• mounting a non-contact probe on said tool support so that a sensitive face portion of said non-contact probe is positioned in proximity to the surface of said workpiece tooth flanks, said non-contact probe being adjusted to provide a non-contact trigger signal whenever the face of the probe is within some predetermined distance of said tooth flank surfaces;
• mounting a contact probe on said tool support so that a sensitive tip associated with said contact probe produces a contact trigger signal whenever the surface of said tip contacts a tooth flank surface of said workpiece;
• storing sets of predetermined work spindle position signals corresponding to the theoretically-correct relative position of the tooth flanks of said workpiece;
• storing sets of instantaneous work spindle position signals indicative of the position of said work spindle whenever trigger signals are provided by said non-contact and contact probe means, respectively, upon passage of said tooth flanks within said predetermined distance and upon contact with the surface of said tooth flanks;
• and
• programming said computer for
• comparing said sets of theoretical and instantaneous work spindle position signals corresponding to the tooth flanks of the workpiece, and
• generating error signals based upon differences between said tooth flank signals.

Apparatus for measuring the tooth flanks of a gear-shaped workpiece rotatably mounted in the work spindle of a computer controlled machine having a tool support, said machine also having encoder means associated with drive means for rotating said spindle, said encoder means providing measurement signals indicative of the angular position of said spindle, said apparatus comprising

• non-contact probe means mounted on said tool support and having a sensitive face portion positioned in proximity to the surface of said workpiece tooth flanks, said non-contact probe means providing a non-contact trigger signal whenever said face is within some predetermined distance from the surface of one of said workpiece tooth flanks;
• contact probe means, mounted on said tool support and movable to a position in which a sensitive tip associated with said contact probe means provides a contact trigger signal whenever the surface of said tip contacts the surface of one of said tooth flanks;
• storage means for receiving and storing
• sets of predetermined work spindle position signals corresponding to the theoretically-correct relative position of the tooth flanks of said gear-shaped workpiece;
• and
• sets of instantaneous work spindle position signals indicative of the position of said work spindle whenever trigger signals are provided by said non-contact and contact probe means, respectively, upon passage of said tooth flanks within said predetermined distance and upon contact with the surface of said tooth flanks;
• said computer being programmable for
• comparing said theoretical and instantaneous work spindle position signals corresponding to the tooth flanks of the workpiece, and
• generating error signals based upon differences between said tooth flank signals.