Electronically controlled top feed arrangement for a sewing machine

Claim 1

An electronically controlled top feed arrangement for a sewing machine comprising: memory means for storing feed data, said feed data including for each stitch a first data portion for a feed stroke and a second data portion for a return stroke; an upper feed dog adapted to alternately apply and relieve pressure upon a work fabric, the application of pressure occurring when the sewing machine needle is out of said work fabric; a presser foot adapted to alternately apply and relieve pressure upon said work fabric, the relief of pressure occurring when said upper feed dog is applying pressure to said work fabric; timing means for supplying a first timing signal during the period when the sewing machine needle is out of said work fabric and a second timing signal during the period when the sewing machine needle is penetrating said work fabric; means operative during formation of a stitch for extracting from said memory means said feed data for said stitch; an actuator coupled to reciprocate said upper feed dog along a feed line in response to control signals applied thereto; and control means responsive to said first timing signal for utilizing said extracted first data portion to provide a control signal for said actuator so as to move said upper feed dog for said feed stroke, and responsive to said second timing signal for utilizing said extracted second data portion to provide a control signal for said actuator so as to move said upper feed dog for said return stroke.