Abstract: An automatic sewing machine is provided wherein the clamps for holding the workpiece can be used to define at least two different sewing patterns. The sewing pattern which is particularly defined by a given arrangement of clamps is indicated to a digital control system within the sewing machine. The control system is operative to subsequently implement an automated stitching of the particular sewing pattern which has thus been indicated thereto. This automatic stitching is accomplished through a sequential reading of a set of instructions previously stored within a memory associated with the control system. The set of instructions remain the same for at least two different sewing patterns. These instructions are altered upon read out by certain control logic which takes note of which pattern has been defined by the given arrangement of clamps. The automated stitching is completed by an automatic ejection of the clamped workpiece.

Abstract: This invention relates to an automatic sewing machine in which the workpiece is moved under the sewing head by means of a clamp which is driven by stepping motors along two coordinate axis through a predetermined pattern. The stepping motors are connected to the workpiece clamp through a non-linear linkage assembly. The stepping motors are controlled by a coded Programmable Read Only Memory (PROM) which generates signals in timed relation to the operation of the sewing machine. The PROM is coded by first digitizing the stitch coordinates of the predetermined pattern and then modifying each of the coordinate values to compensate for the non-linearity of the linkage system.