Step motor drive

An arrangement for transferring a web from a supply spool to a takeup spool at a constant speed comprising a first step and a second step motor, a programmable source of stepping pulses, one of said step motors responsive to said stepping pulses for moving the takeup spool, said other of said step motors responsive to supply spool motion for providing a train of pulses at a rate proportional to the angular velocity of said supply spool, means for counting said provided train of pulses during a predetermined sample interval, said programmable source comprising a memory device including a plurality of addressable storage locations each containing a unique stored value relating to required increments of movement of said one of said step motors, means responsive to the count of said provided train of pulses to address a related storage location of said memory device to read the value stored therein, and means responsive to said read storage value for providing said programmable stepping pulses to said one of said step motors.

An arrangement for transferring material wound on a supply spool to a takeup spool at a constant speed comprising a step motor and a feedback means, a programmable source of stepping pulses, said step motor responsive to said stepping pulses for moving the takeup spool, said feedback means responsive to motion of said supply spool for providing a train of pulses at a rate proportional to its angular velocity, means for counting said provided train of pulses during a predetermined sample interval, and means responsive to the count of said provided train of pulses to program the occurrences of the stepping pulses provided by said programmed source of stepping pulses.

An arrangement for linearly moving at a predetermined velocity material circularly wound on a first carrier to a second carrier for circular winding thereon, first means operating as a drive means and a second means operating as a feedback means, a programmable source of stepping pulses, said first means responsive to said stepping pulses for moving the second carrier, said second means responsive to motion of said first carrier for providing a train of pulses at a rate proportional to the angular velocity of said first carrier, means for counting said provided train of pulses during a predetermined sample interval, and means responsive to the count of said provided train of pulses to program the occurrences of the stepping pulses provided by said programmed source of stepping pulses to said first means to move said material linearly at said predetermined velocity.

An arrangement for transferring material wound on a supply spool to a takeup spool at a constant speed comprising a step motor and a feedback means, a programmable source of stepping pulses, said step motor responsive to said stepping pulses for moving the takeup spool, said feedback means responsive to motion of said supply spool for providing a train of pulses at a rate proportional to its angular velocity, means for counting said provided train of pulses during a predetermined sample interval, means responsive to the count of said provided train of pulses to program the occurrences of the stepping pulses provided by said programmed source of stepping pulses, and means responsive to the absence of a pulse count from said counting means during said predetermined sample interval for terminating the programming of stepping pulses by said programmable source.