Abstract: A method is disclosed for modifying a specific stitch or stitches of a given stitch pattern while the other parts of the pattern remain subject to the standard setting specific to the pattern.

Abstract: In a sewing machine having a machine controller for controlling the rotational speed of the machine and a needle amplitude, adjusting device, a machine control power source switch is provided which is manipulated to produce a switch-over signal, which is identified in a predetermined lapse of time to avoid an erroneous operation of the sewing machine which may be caused by a simple switching operation of the power source switch. The power source switch is released to return to the initial position and is operated again to switch back the machine controller to the function controlling the rotation speed of the sewing machine. The change-over circuit with transmission gates is provided in the sewing machine, which is electrically connected to the amplitude adjusting device and the machine controller and to the control power source switch, respectively.

Abstract: The machine housing of a sewing machine is divided into a bed part provided with a hollow standard and an arm part which overhangs the flat horizontal face of the machine bed part. The machine arm part is connected to the upper end of the standard by a number of fastening bolts. A reamer bolt is first inserted into the upper end of the standard through the bottom of the bed part to provisionally connect the arm part to the standard, and then an eccentric pin inserted into respective bores provided in both parts of the housing is rotated to turn the machine arm part around the reamer bolt with respect to the machine bed part. After the arm part has been adjusted with the flat face of the bed part both parts are fastened to each other by fastening bolts.

Abstract: A sewing machine includes a main drive shaft rotatably mounted in said housing for vertically reciprocating a needle penetrating a fabric to produce stitches therein, a shaft extending transverse to the main drive shaft and rotatably mounted in the machine housing, a worm and a worm gear between said main drive shaft and the transverse shaft for rotating the latter at a speed smaller than the rotational speed of the main shaft, a plurality of pattern cams and a plurality of feed control cams mounted on the transverse shaft for rotation therewith.

Abstract: An automatic thread setting device for electronically controlled material and needle position type sewing machines. The device has pattern selecting means, cloth thickness designating means, upper and lower thread tension adjusting means, and electronic memory means. Selection of a pattern automatically sets the thread tension. Selection of a different pattern automatically resets the tension.

Abstract: A method of producing hemstitches by means of a zigzag stitching presser foot comprises the steps of forming two fixing stitches at one point adjacent an edge of the fabric with feeding of the fabric in one direction while reciprocating the needle a small distance laterally, two stitches laterally spaced apart from each other and from the fixing stitches and formed with feeding the fabric in the one direction without lateral movement of the needle, and two crossing stitches interconnecting the fixing stitches with the lateral stitch remote from the one point and being formed with feeding the fabric in the opposite direction.

Abstract: A sewing machine produces patterns of stitches including straight stitches, in which a single operating dial is manually operated to select one of the patterns with a proper feeding amount in one rotation range thereof, and to vary feeding movement with a specific cycle in relation to the same patterns in another rotation range thereof to produce so called "super patterns".

Abstract: An electric sewing machine has an A.C. driving motor controlled by a triac; a controlling circuit for the triac includes a thyristor powered by a lower-voltage battery via an adjustable RC-circuit; the controlling circuit is electrically insulated from the A.C. power-supply circuit by an optoelectric coupler, the optical part of which is connected to the A.C. circuit and the electric part of which controls the gate of the thyristor in synchronism with the A.C. voltage; the thyristor in the controlling circuit is coupled to the triac by means of an insulating pulse transformer.

Abstract: A lock stitching and overlock stitching machine has a primary driving means, a lock stitching device including a drive shaft, an overlock stitching device including a separate drive shaft and being spaced apart from the lock stitching device, the drive shafts of respective stitching devices being coupled to the primary driving means by a clutch means which is operable to rotate the drive shaft of the lock-stitching device in one direction relative to the user and the drive shaft of the overlock-stitching device in an opposite direction relative to the user.

Abstract: A pattern selecting system is disclosed in which a single set of push buttons is utilized to select a first group of patterns each of which corresponds to a particular push button and a second group of patterns indicated by a series of two figure numbers.

Abstract: A free arm sewing machine is provided with a manually operated arrangement for positioning and holding the sewing machine body relative to its base. This arrangement comprises a transverse shaft turnable in the base of the sewing machine, an operating dial secured to the shaft and a disc also secured to the shaft and having a pin engageable with a groove formed in the free arm of the sewing machine.

Abstract: An upper shaft phase detecting system in which the rotation speed of the upper shaft is sensed and utilized to vary the time at which data starts to be released from an electronic memory of a sewing machine.

Abstract: A thread tightening device for a sewing machine of the type having a main shaft, a vertically reciprocable needle bar with a needle carrying an upper thread, a loop taker and a drive shaft for driving the loop taker and a feed dog, the thread tightening device includes a group of pattern cams operatively connected to the main shaft, pattern selecting device and an arrangement for controlling the vertical movement of the feed dog. This arrangement comprises a control cam and a rotatable shaft, the control cam being slidably axially mounted on the rotatable shaft but not turnable with respect to the shaft. The thread tightening device also includes an element arranged for vertical reciprocating movement in a timed relation with the feed dog, which element engages a lower thread during the stitching operation of the sewing machine.

Abstract: A device for automatically adjusting the tension of a lower thread, which comprises a lower thread bobbin arranged on a bottom plate of a bobbin carrier turnably carrying the bobbin, a loop taker mounted on a magnetic shaft, and an energizing coil arranged around the magnetic shaft and providing together with said bottom plate and magnetic shaft a path of magnetic flux. The device is further provided with a detector detecting the consumed amount of the bobbin thread and a control circuit for energizing the coil when the lower thread is wound to the maximum capacity of the bobbin, interrupting the light of the detector. The detector operates the control circuit to decrease the amount of electric current applied to the energizing coil so as to set the lower thread tension back to its initial predetermined value.

Abstract: A needle holding device for a sewing machine having a needle with a cylindrical shank having a flat edge surface extending along the shank includes a needle bar for supporting the needle, a needle holder mounted to the needle bar and a holding screw to fasten the needle to the needle bar. The needle bar is formed with a vertical groove defined by a horizontal wall and an inclined wall which are adjacent to each other to define a wedge-shaped space. The needle holder has a vertical circular hole having an inner periphery and a transverse hole extended into the vertical hole. When the needle holder is mounted to the needle bar the inner periphery of the vertical hole and the wedge-shaped space of the needle bar groove form a wedge-shaped chamber into which the shank of the needle is inserted. The holding screw fastens the needle upon insertion into the needle bar when the flat edge of the shank is positioned against the horizontal wall of the groove.

Abstract: Patterns stored in the memory of an electronic sewing machine are divided into a group of patterns which is more frequently used and a group of patterns which is less frequently used. Patterns which are more frequently used can be selected by individual pushbuttons, and corresponding panels depicting such patterns will be lit up. Patterns less frequently used are listed by either a two digit decimal number or an alphameric character, and are selected by operation of one of two additional pushbuttons, and at least one character representing the pattern selected is displayed.

Abstract: A sewing machine comprises a housing, a needle bar adapted for reciprocating movement by a main shaft rotatably mounted in the housing and a fabric feeding device. A pattern control device is provided in the sewing machine which includes a number of needle bar control cams and fabric control cams operated by the main shaft. Two manually operated pattern selecting arrangements are mounted in the housing of the sewing machine including cams and cam followers and which are operatively connected to the fabric feeding device to control the movement thereof. In accordance with these pattern selecting arrangements the minimum rotation angle of the operating dial is made considerably large for selecting one of the pattern cams to thereby provide relatively small push angles for operating cam followers.