Abstract: A zigzag sewing machine includes an oscillating hook. The transverse needle swing amplitude of the needle of the sewing machine is increased in amplitude from that of conventional free-arm domestic sewing machines with oscillating hooks, for example, from 5 mm to 9 mm. The increased amplitude is provided by a novel drive mechanism including a rack oscillating transversely between two extreme positions in response to rotation of a driving wheel and a pinion engaging the rack. The pinion is coupled to and drives the oscillating hook. The pinion may have a variable radius, may be coupled to the driving wheel through other racks and pinions, and may be coupled to the driving wheel through a multiple bar linkage. A constant rotation speed of the driving wheel causes the hook to oscillate at a rotational velocity that varies with rotational position of the hook so that swing amplitude of the needle transverse to the linear direction may be increased.

Abstract: A driving apparatus for an oscillating catcher of a sewing machine includes a toothed pinion being eccentrically mounted on a driving shaft for the catcher for the sewing machine. A transmission device, having teeth, is guided in a back-and-forth movement by an oscillating crank drive, with the teeth of the transmission device engaging the tooth pinion on the driving shaft. By arranging the toothed driving gear eccentrically on the driving shaft of the catcher, it is possible to substantially increase the speed of the point of the catcher when it seizes the loop of the upper thread offered by the needle.

Abstract: A shuttle hook driver for a sewing machine includes a driving pulley mounted on a main shaft, a driven pulley rotatable about a second shaft substantially crossing the shaft center of the main shaft and extending horizontally, a timing belt extending between the driving and driven pulleys and twisted approximately 90 degrees, and a converting mechanism for converting rotation of the driven pulley to reciprocation of the shuttle hook.

Abstract: An oscillating shuttle, including a shuttle race having a substantially annular guide groove including two end portions opposed to each other in a circumferential direction thereof, a shuttle body which includes a part-annular guided portion and a hook portion and which is oscillatory while the guided portion is guided by the guide groove, a driver which rotates the shuttle body about an axis line, wherein when the hook portion hooks a thread loop, the shuttle body is rotated by the driver in one of opposite directions such that the tail portion passes through one of the two end portions of the guide groove and enters an upper opening of the shuttle race and, when the shuttle body is rotated back in the other direction, a tail portion of the guided portion enters the one end portion of the guide groove, and at least one of the one end portion of the guide groove which has, in a direction parallel to the axis line, a width greater than a width of a remaining portion of the guide groove, and the tail portion of

Abstract: A needle receiving assembly for a sewing machine comprising a throat plate through which a sewing needle can pass and a needle collar for regulating a rear loop of an upper thread passing through the sewing needle. The position of the needle collar relative to the sewing needle is adjustable.

Abstract: An oscillating loop taker includes a bobbin case holder having a needle thread guiding projection which with a wedge forms a recess in which fits a driver member. A radial dimension from an axis of rotation of the holder to an inner leading edge portion of the projection is less than a radial dimension from such axis to an inner surface of the holder defining a space within which is housed a projection. The inclination of a needle thread guide face at the recess side of the projection is set to a desired comparatively large value. The circumferential length of the needle thread guide face is made comparatively long to enable a needle thread to be easily transferred onto the outer circumferential face of the bobbin case. Thereby, the bobbin thread is permitted to pass between the inner peripheral face in the vicinity of the base end portion of the projection and the outer peripheral end portion of the bobbin case.

Abstract: The takeup limb of each needle thread loop in a central bobbin hook type sewing machine is engaged by a kidney-shaped cam on the shuttle hook driver and by a projection on the housing for the hook while the takeup lever of the machine reduces the size of the loop. This ensures that the takeup limb is held and the loop is guided substantially during the entire interval of reduction of the size of the loop. The cam has a lobe with a groove for the takeup limb, and the projection of the housing engages the loop prior, during and subsequent to withdrawal of the takeup limb from the groove of the lobe.

Abstract: One limb of each loop which is formed by the needle thread in an oscillating hook type sewing machine is temporarily in contact with the loop-engaging member of a braking device whose torsion spring is non-rotatably installed in the hollow mandrel of the hook. The loop-engaging member is turned by successive loops from a starting position, relative to the hook and against the opposition of the spring so that it tensions the loop while the latter is raised by the takeup lever. The spring thereupon rapidly returns the loop-engaging member to its starting position. The loop-engaging member is integral with a loop catcher which intercepts the loop when the latter is cast off the hook and which ensures that the loop comes in contact with the loop-engaging member.