Abstract: This invention is a device and method for avoiding dead centers in an in-line slider-crank mechanism when it is used to convert linear to rotary motion. The usual straight connecting rod is replaced by an L-shaped connecting rod operating in conjunction with two deflecting pillars. The side-arm of the L-shaped connecting rod travels between the two pillars which are strategically sized and placed, and intended to deflect the side-arm. As a consequence, the crankpin end of the connecting rod is automatically deflected away from the dead center positions, thus avoiding them, and enabling the rotation to become continuous and un-interrupted.

Abstract: A sewing machine includes a needle bar, a needle bar base, a base frame, a guide member, and a fixing member. A sewing needle is attachable to a lower end portion of the needle bar. The needle bar base is configured to support the needle bar to allow the needle bar to be moved in an up-down direction. A first engagement portion is provided to a lower end portion of the needle bar base. The base frame is configured to swingably support an upper end portion of the needle bar base. A second engagement portion is provided to a lower end portion the base frame. A guide member includes a third engagement portion configured to engage with the first engagement portion and guide movement of the first engagement portion in a predetermined direction and a fourth engagement portion configured to engage with the second engagement portion.

Abstract: A sewing machine includes a needle bar base, a support shaft, an adjustment member, and an urging portion. The needle bar base has a through hole on an upper end portion. The support shaft is inserted through the through hole and pivotably supports the needle bar base. The support shaft includes a leading end portion. The leading end portion includes a first screw portion. The adjustment member is provided on the support shaft and is configured to move along an axial direction of the support shaft. The adjustment member includes a second screw portion and a first contact portion. The second screw portion is screwed into the first screw portion. The first contact portion is in contact with the needle bar base. The urging portion urges the needle bar base toward the first contact portion of the adjustment member.

Abstract: A presser foot drive structure of an embroidery machine, by which a vertically movable presser foot for preventing a sheet of cloth to be sewn from rising in a sewing operation is vertically moved inside a sewing head. The presser foot drive structure includes a presser foot drive holder, which is vertically slidable and is mounted on the outer circumference of a needle bar, which is vertically driven; a presser foot drive shaft, which is disposed parallel to the needle bar via the presser foot drive holder; and the presser foot, which is disposed at the lower end of the presser foot drive shaft and vertically reciprocates. It is possible to reduce the stroke of a presser foot so that it is smaller than that of a needle bar, enhance the supporting force for a needle bar, and reduce the shaking of a presser foot.

Abstract: A presser foot drive structure of an embroidery machine, by which a vertically movable presser foot for preventing a sheet of cloth to be sewn from rising in a sewing operation is vertically moved inside a sewing head. The presser foot drive structure includes a presser foot drive holder, which is vertically slidable and is mounted on the outer circumference of a needle bar, which is vertically driven; a presser foot drive shaft, which is disposed parallel to the needle bar via the presser foot drive holder; and the presser foot, which is disposed at the lower end of the presser foot drive shaft and vertically reciprocates. It is possible to reduce the stroke of a presser foot so that it is smaller than that of a needle bar, enhance the supporting force for a needle bar, and reduce the shaking of a presser foot.

Abstract: An upper decorative stitching device is designed to make it possible to precisely transmit the swing movement of a first lever which is capable of swing movements widthwise in a pendulum manner to horizontal reciprocating motion of a second lever, which is provided with a spreader. The device facilitates the operation of switching between an upper decorative stitching and no upper decorative stitching. A connecting rod (9) is provided at both ends with spherical bearings (10, 11) to provide a connection between the first lever (3) and the second lever (8), thereby converting the rotation of the upper shaft into the reciprocal movement of the spreader.

Abstract: An oblique thread-guiding link of a sewing machine, including a swing arm having a front swing arm and a rear swing arm and formed with a central shaft hole. A pivot shaft is fixedly fitted in the shaft hole of the swing arm. Two ends of the pivot shaft are obliquely pivotally mounted in two opposite sidewalls of the housing of the sewing machine. One end of the pivot shaft protrudes from the housing of the sewing machine. The front end of the front swing arm is positioned above a needle holder mechanism and aligned and coupled therewith. The rear end of the rear swing arm is positioned above a driving mechanism and aligned and coupled therewith. One end of a thread-guiding fixing seat is fixedly connected with the protruding end of the pivot shaft and can be swung along with the swing arm.

Abstract: In a presser foot device of a sewing machine, a presser foot is vertically movably supported to a sewing machine body frame by a presser bar. A drive device moves the presser bar up and down in accordance with a drive signal. A sensor detects when the presser foot is raised close to a top dead center position, that is, a predetermined position. Based on the detection by the sensor, a control device controls the drive signal for the presser foot drive device.

Abstract: A manually driven stitcher or sewing machine. A lever of the stitcher is manually pivotable through an arc to reciprocate a stitching mechanism. When pivoted through the arc, the lever also actuates a clamping assembly, an article advancing mechanism, and a stitching material supplying assembly. The stitcher or sewing machine of the present invention may be used to manually stitch a variety of materials including heavier ones such as leather, nylon strapping, plastic, and rubber.

Abstract: A workpiece puller mechanism for a sewing machine including a carrier including a feed shaft mounted thereon that supports a feed roller. The periphery of the feed roller is biased downwardly into engagement with the upper surface of the workpiece while the lower surface is engaged by the feed dogs. A puller housing is mounted on the sewing machine having a puller shaft rotatably mounted for rotation therein. Rotation of the puller shaft is imparted by a timing belt that overlies sprockets on the sewing machine main drive shaft and the puller shaft. The puller shaft carries a crank head that is connected by a connecting bar assembly to the input member of a one way clutch assembly. The one way clutch assembly provides drive in one direction only to the drive shaft for the feed roller.

Abstract: A drive mechanism for connecting the output drive of a tufting machine pattern control to the needle bar of the tufting machine includes a linkage having a pair of links each connected at one end to a plate fastened to the output drive rod of the pattern control and having second ends which are connected to a lever at spaced apart locations. One end of the lever is connected to the needle bar of the tufting machine. One of the links is substantially longer than the other link and the locations of the connection to the lever is such that the attachment of the lever to the needle bar produces substantially vertical straight line motion at that point as the needle bar reciprocates. Thus, the needle bar may be shifted laterally by the mechanism as determined by the pattern control, and yet reciprocates in a straight line path.

Abstract: A control device for a cyclic sewing machine for controlling driving condition of a main shaft of a cyclically operated sewing machine. The control device includes a clutch mechanism provided between a driving source and a main shaft, a switching member for switching the clutch mechanism between a power cutoff condition, a low-speed drive condition and a high-speed drive condition, a control cam rotatable at a reduced speed in interlinked relation to the main shaft, and a lost-motion connecting means. When switch the sewing machine from the power cutoff condition to the low-speed condition, a lost-motion is produced between the operating member and the switching member. The control cam is rotated in response to rotation of the main shaft, the operating member and the switching member are moved in accordance with cam profile. The clutch mechanism and hence the main shaft are switched between the drive conditions based on the movement of the switching member.

Abstract: In a fabric feeding mechanism of a sewing machine there are provided a pair of elastic members each connected between two pivot axes at both ends of each of a pair of link elements. The elastic members have their pitches slightly different from those of the corresponding link elements and elastically displaceable in the longitudinal direction of the latter, so that backlash which may be caused at the pivot axes by abrasion resulting from repeated use of the sewing machine will be absorbed to thereby maintain a predetermined feed referenced point thereof.

Abstract: A workpiece holding-down device for a sewing machine comprises a spring-loaded presser bar and foot assembly supported in the framework of said sewing machine, a drive mechanism for moving said assembly vertically, and a control circuit for controlling the movement of said presser bar. The foot assembly includes signal means for positioning the presser bar and foot assembly in a controlled position in response to the actuation of an operation member or stored information.