Method and machine for versatile stitching

A method of stitching a corner pattern requiring the stitching of an outer corner and an inner corner, the corner pattern being formed by operating a first needle along an outer stitch path in conjunction with operating a second needle along an inner path, disabling the second needle when the apex of the inner corner has been reached and sewing only with the first needle until the apex of the outer corner is reached, rotating the second needle about the apex of the outer corner while maintaining the first needle substantially at the apex of the outer corner, operating the first needle along the new outer stitch path, pulling the thread back through the second needle by an aggregate amount substantially equal to the amount of thread pulled out during the relative movement of the second needle and the pattern following the disablement of the second needle, again operating the second needle along a new inner stitch path when the apex of the inner corner is passed by the second needle.

A sewing machine operable on a workpiece translatable in its own general plane along predetermined paths comprising stitching instrumentalities rotatable about an axis of rotation normal to said plane, said instrumentalities comprising both a needle bar reciprocable on said axis of rotation for carrying at least one needle into and out of the workpiece and a stitch-forming assembly operative on the opposite side of the workpiece from the needle for hooking thread fed therefrom, means for rotating both said needle bar and said stitch-forming assembly about the axis of rotation, and an automatic control system for ordering a sequence of predetermined angular rotations for controlling said means for rotating both said needle bar and stitch-forming assembly.

A machine as in claim 11 wherein said means for counteracting the rotation of said thread hooking devices about their respective axes in response to a rotation of said stitch-forming assembly further comprises:

• means for rotating said thread hooking devices about their respective axes;
• means for differentially connecting said means for rotating said hooking devices about their respective axes with said means for rotating said stitching instrumentalities, said differential connecting means being operative to drive said means for rotating said hooking devices in a manner which counteracts the rotation of said hooking devices that is caused by the rotation of said stitch-forming assembly.

In a sewing machine including a workpiece support and means for guiding the support predeterminedly in a plane, a reciprocable needle bar, rotatable about an axis of rotation, for carrying a plurality of sewing instrumentalities toward and from successive workpiece engaging localities, mechanism for reciprocating the needle bar, an under-work stitch-forming assembly, and a control means synchronized with said reciprocating mechanism and responsive to predetermined control data for rotating both the needle bar and the under-work stitch-forming assembly about said axis of rotation when the sewing instrumentalities are disengaged from the fabric to selectively vary the angle of rotation of the needle bar and the under-work stitch-forming assembly for each successive stitch to be made by the instrumentalities.