Friction drive apparatus for strip material

A friction drive apparatus for feeding a strip material in a longitudinal direction along a feed path for performing a work operation such as printing, plotting, or cutting, said strip material having a first longitudinal edge and a second longitudinal edge, said friction drive apparatus comprising:

• a first friction wheel associated with said first longitudinal edge of said strip material;
• a second friction wheel associated with said second longitudinal edge of said strip material;
• a first motor drive for rotating said first friction wheel;
• a second motor drive for rotating said second friction wheel;
• a sensor disposed behind said first friction wheel with respect to direction of motion of said strip material for substantially continuously monitoring lateral position of said strip material and generating a sensor signal upon detection of a lateral deviation of said strip material from said feed path;
• and
• a motion processor for controlling speed of said first motor drive and said second motor drive differentially in response to said sensor signal for correcting position of said strip material during said work operation.

A friction drive apparatus for feeding a strip material in a longitudinal direction through a feed path for performing a work operation such as printing, plotting, or cutting, said strip material having a first longitudinal edge and a second longitudinal edge, said friction drive apparatus comprising:

• a first friction wheel disposed along said first longitudinal edge of said strip material;
• a second friction wheel disposed along said second longitudinal edge of said strip material;
• a first motor drive for rotating said first friction wheel;
• a second motor drive for rotating said second friction wheel;
• a sensor disposed behind said first friction wheel with respect to direction of motion of said strip material for monitoring lateral position of said strip material and generating a sensor signal during movement of said strip material upon detection of a lateral deviation of said strip material from said feed path;
• means for detecting an actual longitudinal position of said strip material;
• and
• a motion processor for controlling speed of said first motor drive and said second motor drive independently upon receiving said sensor signal, said motion processor imposing a differential signal upon said first and second motor drives to correct lateral deviations of said strip material from said feed path, said motion processor comparing a commanded longitudinal position and said actual longitudinal position of said strip material to detect and correct longitudinal error, said lateral deviation and longitudinal errors being corrected during performance of said work operation.