Control apparatus for a machine for cutting a workpiece

Control apparatus for a machine for cutting a workpiece by means of a cutting tool in displacement against the workpiece, which control apparatus is operable to impose a program of speeds on this displacement, the said machine comprising a horizontal table to support the workpiece, a horizontal jig which defines a path for cutting, a freely displaceable carriage equipped with the cutting tool and a motor adapted to displace the carriage along the jig;

• the said apparatus comprising:
• a programming element having zones of varying transparency or reflectance;
• an emitter unit for emitting light beams to the programming element an an associated receptor unit for receiving the light beams which have been transmitted or reflected;
• means for turning the programming element so that one complete rotation of the programming element corresponds to one complete displacement of the carriage along the jig;
• an electric circuit connected to the receptor unit and to the motor for controlling the speed of rotation of the motor as a function of the intensity of the signal provided by the receptor unit so that the speed of displacement of the cutting tool varies during the movement along the path according to the program defined by the zones of the programming element.