Abstract: A sewing machine including a control device and a plurality of driving devices adapted to be controlled by the control device, in which one of a plurality of operating panels is selectably connectable to the control device. When one of the operating panels is connected to the control device, the control device controls the driving devices according to a selected additional control program. When none of the operating panels is connected to the control device, the control device controls the driving devices according to a basic control program. The operating panels are adapted to output discrimination signals peculiar to each of the operating panels so that the control device discriminates the operating panel selected and connected.

Abstract: The invention relates to a sewing machine provided with a needle reciprocated according to rotations of a main shaft and work feeding devices actuated synchronously with rotations of the main shaft, setting a margin to sew from a trailing edge to a sewing end position. The sewing machine includes devices for computing a terminal stitch length according to a set margin width. Control devices are provided for controlling a sewing to be carried out for coping with that which corresponds to the terminal stitch length computed by the computing device. The sewing machine further comprises computing devices for applying a correction to at least one of a number of stitches and a feed pitch, as occasion demands, where there arises the remainder as the result of an operation of the computing devices, and control devices for controlling the sewing to be carried out according to the computed result.

Abstract: A sewing machine forms a seam in the form of a series of stitches for a length preset by the operator. The length of the seam formed is computed from feed pitches data each generated when one stitch is formed. The operation of the sewing machine is stopped when the computed seam length coincides with the preset seam length.

Abstract: Herein disclosed is a control unit for providing seam length control of a sewing machine which comprises: a main shaft; a sewing needle in accordance with the rotations of the main shaft for forming stitches in a work fabric which is placed on a work supporting surface so that it may be sewn; a feed dog for feeding the work fabric while passing a sewing point of the sewing needle; a work feed mechanism including a feed bar for carrying the feed dog and a feed shaft for supporting the feed carriage, the work feed mechanism being adapted to impart motions in a feeding direction to the feed dog by the reciprocating rotations of the feed shaft in accordance with the rotations of the main shaft; and mechanical adjusting means interposed between the work feed mechanism and the main shaft for adjusting a feed pitch of the feed dog by changing the reciprocating stroke of the feed shaft.

Abstract: A sewing machine has an automatic control system. This system provides for an automatic sewing mode for sewing according to previously stored sewing data and an ordinary sewing mode for sewing independently of the stored sewing data. When an interruption signal is generated by an interruption signal generating device during sewing process in the automatic sewing mode, the ordinary sewing mode is set and the pressure on the presser foot is released. Therefore, it is capable of smoothly feeding a material when feeding direction of the material is varied.

Abstract: A presser device for a sewing machine, comprising: pressing means reciprocally movable between a holding position in which it presses and holds a workpiece and a releasing position in which it is spaced the farthest from the workpiece; drive means for driving the pressing means; means for controlling the drive means so that the pressing means is brought into the holding means before the start of the sewing operation of the sewing machine; means for controlling the drive means so that the pressing means is brought from the holding position to the releasing position after the end of the sewing operation; timer means for setting a predetermined time from the instant when the pressing means is brought into the releasing position; and means for controlling the drive means so that the pressing means is brought from said releasing position to an optional intermediate position between the releasing position and the holding position after lapse of the predetermined time.

Abstract: A numerically controlled sewing machine for controlling the movement of a workpiece holding means according to a program made on the basis of a basic standard size of a basic standard piece and the shape of a basic standard seam to be formed on the basic standard piece.