Abstract: Method and apparatus for aligning fabric as it is advanced in a prescribed direction toward a sewing machine such as a double overlock seamer for stitching pants. Photosensitive devices sense displacement of edges of upper and lower fabric plies relative to a desired alignment line. Error signals are produced when either ply edge is displaced from the desired alignment line. Friction wheels responsive to the respective error signals guide each ply toward the desired alignment line as it is advanced toward the sewing machine. Each friction wheel pivots about an axis perpendicular to the ply and is controlled by a stepper motor. Each friction wheel is movable between an operating position in which it is biased against the respective fabric ply, and a retracted position for insertion or removal of fabric. The pressure applied to the fabric ply by the friction wheel is adjustable.

Abstract: In a sewing machine for performing twin overedging and seaming in one high-speed operation, specially designed top and bottom variable feed dogs pull the two plies through a three needle stitching area with improved, simplified elements for diverting one ply edge while the other is being overcast. The upright overcast edge of the top ply passes through a tunnel formed through the top feed dog. A guide wall attached to the throat plate guides the top edge away from the bottom overedging station. A guard wall can be attached to the presser foot to keep the turned-up top edge away from the seaming needle. A fiber optic/pneumatic system controls automatic stop, presser foot/top feed retraction and between-work thread cutter functions. Alternative front edge guides facilitate feeding the two plies in registration.