Computer-aided drawing or engraving device

A drawing or engraving device or plotter comprising:

• first and second travelling carriage systems, the first travelling carriage system comprising a first guide rail having a first travelling carriage movable along the first guide rail, and a second guide rail having a second travelling carriage movable along the second guide rail;
• the second travelling carriage system comprising a third guide rail having a third travelling carriage movable along the third guide rail, and a fourth guide rail having a fourth travelling carriage movable along the fourth guide rail, the third guide rail being linked to the second travelling carriage;
• a working head on the fourth travelling carriage;
• means for measuring the distances covered by the travelling carriages in different distances in order to indicate the actual coordinates in a selected coordinate system which the working head executes during use;
• drive means to drive the third and fourth travelling carriages, the drive means being locked when in a nonactivated state;
• programming means having input means for selection of selected coordinates which the user would like the working head to pass through during use;
• a memory for storage of the selected coordinates, the memory being operatively connected to the programming means;
• a computer which is operatively connected to the measuring means as well as to the memory and which determines any deviation of the actual coordinates from the selected coordinates;
• and
• control means operatively connected to the computer and to the drive means, the control means causing the drive means to drive the third and fourth travelling carriages to compensate for the deviation.