Sewing machine for large-surface, frame clamped material

A sewing machine for large surfaced material comprising means for sewing upon relatively large surfaced material, means for effecting longitudinal and transverse displacement of said sewing means, a pair of endless conveyors disposed in general side-by-side relationship, each of said pair of conveyors being defined by upper and lower generally parallel conveyor runs and opposite bight conveyor runs therebetween, a sewing zone being located generally between said opposite bight conveyor runs, a loading zone being disposed generally outside of said sewing zone, said pair of endless conveyors each having first and second coupling means for selectively coupling and uncoupling with respect to third and fourth coupling means of respective first and second frames, said first and second frames each being adapted to hold respective first and second relatively large surfaced material which is sewn in said sewing zone by said sewing means, said first and second coupling means being spaced a maximum distance between each other as measured in predetermined opposite directions of conveyor runs travel, said maximum distance between said first and second coupling means being at least equal to one linear dimension of said frames, and means for selectively simultaneously driving said pair of endless conveyors to simultaneously move one of said frames from said loading zone in a first direction of travel established by a first portion of each of said pair of said conveyors while simultaneously moving the other of said frames from said sewing zone to said loading zone in a second direction of travel established by a second portion of each of said pair of said conveyors opposite to said first direction.