Abstract: A sewing machine includes a sewing needle, a lower looper, a motor for driving the sewing machine, and a controller for controlling the driving and stopping of the motor. When, in the sewing machine, the controller operates to stop the motor, stop control means operates to stop the motor such that said sewing needle is stopped at a time corresponding to the time just before the sewing needle reaches the bottom dead point and to the time that a needle thread disengages from the sharp tip of the lower looper.

Abstract: A thread spreading apparatus for use in an overlock sewing machine capable of performing over-edge chain stitching and other stitching. The thread spreading apparatus uses a lower looper for over-edge chain stitching to allow a needle to surely drop into a triangle defined by a needle thread, a looper thread and the lower looper, thereby enabling multi-thread chain stitching and covering chain stitching to be performed without fail. The apparatus includes a thread spreading hook having hook portions with different heights for retaining needle threads and a projection formed on one of the hook portions. During stitching other than over-edge chain stitching, the hook portions of the thread spreading hook retain the needle threads when two needles drop, thereby allowing each needle to drop into a triangle defined by the looper thread, the lower looper and the corresponding needle thread.

Abstract: A guide device for a sewing machine which is used for at least hemming of a bottom of a work, sewing a tape on the work and sewing a rolled hem tape on the work comprises four guide members. A first guide member has a regulating surface for regulating an edge of the tape supplied beneath the work, and is mounted on the bed of the sewing machine. A second guide member has two regulating surfaces which regulate the position of one edge of the work or one edge of the rolled hem tape and the position of the other edge of the rolled hem tape, respectively, and is fixedly mounted on the first guide member. A third guide member has a narrow space into which the work or one fold of the rolled hem tape is inserted, and is mounted on the first guide member. A fourth guide member has a pushing surface for pushing the other fold of the rolled hem tape against said second guide member, and is mounted on said third guide member.

Abstract: In an overlock sewing machine for an overedge stitch and at least one kind of chain stitch other than the overedge stitch, an upper knife releasing device according to the invention comprises: an upper knife rocking arm 26 to which an cloth cutting upper knife 30 is secured; an upper knife rocking shaft 28 which is fixedly secured to the upper knife rocking arm and is rotatably supported relative to a frame; a controller shaft 50; and a controller 52 having a guide groove 52a, the controller being rotatable about the controller shaft, a link mechanism (38 and 34) having one end which is linearly reciprocated along the guide groove, and the other end which is fixedly secured to the upper knife rocking shaft.

Abstract: A safety device for sewing machines such as an overlock sewing machine and the like including a stopper secured to the sewing machine, a lever pivoted to a looper cover, a pin, a spring provided thereon, and engageable members formed on a chip guard cover and an auxiliary bed, respectively. A switch is so mounted on the sewing machine as to render the latter actuated when it is in contact with the looper cover.

Abstract: There is provided a needle attachment position indicator device for use in a sewing machine of a type comprising a stitch pattern forming mechanism provided in a machine frame for permitting selection of one stitch pattern from a plurality of different stitch patterns, an actuator member disposed in the machine frame for permitting selection of the stitch pattern, an actuation mechanism disposed in the machine frame for setting the stitch pattern forming mechanism at selected stitch pattern in response to the selective actuation of the actuator member, and needle holding means having a plurality of needle attachment positions. The device includes an indicator member capable of indicating needle attachment position corresponding to the selected stitch pattern, in response to the selective actuation of the actuator member.

Abstract: The thread tension regulating apparatus comprises; thread tension setting means for selecting and setting thread clamping pressure to the right pressure coping with plural kinds of the stitches; thread tension fine-adjusting means for allowing fine-adjustment of thread clamping pressure in the thread tension regulating apparatus by moving clamping pressure of the thread tension regulating apparatus from the original position to a higher position; said clamping pressure having been adjusted by said thread tension setting means; and home-position resuming means for returning the thread tension fine-adjusting means to the home position from another position when selecting and setting another thread tension by using the thread tension setting means.

Abstract: An overlock sewing machine is provided with means for driving a lower looper according to a plurality of different oscillational movements independently of each other, a clutch mechanism for changing the aforementioned movements from one to the other mode, a back and forth drive mechanism for moving a lower looper back and forth, a mechanism for transmitting movement of the back and forth drive mechanism to a lower looper and releasing transmission of the movement therefrom, a lower looper oscillating means for oscillatively moving a lower looper, a mechanism for releasing oscillational movement of the upper looper therefrom, and a motion change-over device for interchanging operation between the clutch mechanism, the transmission and release means, and oscillational movement release means. The arrangement permits conversion of various stitch formations in a sewing machine to take place in a simple manner without requiring complicated adjustment.

Abstract: An overlock sewing machine which is arranged such that a lower thread take-up lever is disposed independently of an upper looper thread take-up lever and that a lower looper thread take-up lever drive mechanism is fabricated independently of an upper thread take-up lever drive mechanism and adapted to connect thereto an adjust means for adjusting the amount of thread fed from the lower looper thread take-up lever.

Abstract: A threading mechanism where a thread catcher hook is reciprocated between two needles by a movable means. Although the two juxtaposed needles are separated horizontally and vertically, position aligning means places the hook opposite either needle eye, thereby facilitating threading both needles and greatly improving sewing efficiency.

Abstract: A cam shaft of a rotary looper thread take-up is extended short of a thread guide and thus provides a free space there-between. A thread introduced from the tip-end-side of the cam shaft is prevented from being entangled into the cam shaft when the looper thread becomes broken. In a preferred embodiment, three slit-like guides placed in parallel and two cams placed there-between are effective to introduce the looper thread into the rotary looper thread take-up by a simple operation without requiring an operator to visually align the thread to pass through an eyelet.

Abstract: There is disclosed an overedge width regulating device capable of adjusting overedge width by rotating a knob which causes both a overedge-width latch and a lower knife to move simultaneously. The device permits adjustment of the overedge-width latch independently from the lower knife and the release of the overedge-width latch during the roll hemming process. Thus, without regard to material being sewn, knitted or woven, a tight and well-balanced overedge finish is obtained while, at the same time, the overedging process is greatly improved from the viewpoint of both quality and time.