Thanks to the multiple knife-dropping function, it is no longer required that the knife be changed at the buttonhole size is changed. The knife supports sewing lengths of 41mm at the maximum. In addition, knife mechanisms for 70mm and 120mm are optionally available. With this, slots such as the belt holes of child seat belts can be buttonholed. Needle thread tension for sewing parallel and bartacking sections of buttonholes can be separately controlled through the operation panel and stored in memory according to various sewing conditions (e.g., type of thread, type of material and sewing speed). LBH-1796A: Buttonholing machine with a 220mm work clamp which supports the simplified indexer function has been added to the family of buttonholing sewing machines. LBH-1790AB: Computer-controlled, High-speed, Buttonholing Machine with a shorter-thread remaining function. The newly-developed shorter-thread remaining mechanism trims the thread short and eliminates the trouble of manual thread nipping. Twenty different programs can be registered, and as many as 30 different patterns can be stored in one program. The machine is able to continously sew two or more diffrent patterns without requiring the work clamp foot to be lifted. As may as 20 programs can be registered, and six different patternscan be stored in one program. (Related pats need to be exchange for optional ones.) Electronic control of the material feed mechanism, needle feed mechanism, needle thread trimming mechanism, bobbin thread trimming mechanism, cloth trimming mechanism, presser lifter mechanism and other mechanisms has been achieved. All adjustment values are digitaliced to enable the operator to set and store those values on the operation panel. The machine is provided as standard with a newly-developed auto-lifter driven by a stepping motor. This helps reduce the operator’s fatigue. As for the pedal, one-pedal and two-pedal models can both be changed over and the intermediate stop, which facilitates positioning of the sewing product, can be specified. The work clamp foot lift can be set as desired. The reverse-rotation needle-up function offers a maximum work clamp foot lift of 17 mm. Thanks to the multiple knife-dropping function, it is no longer required that the knife be changed at the time the buttonhole size is changed. The number of knife dropping times can be automatically set according to the buttonholing size in cases where the buttonhole size is frequently changed for small-lot productions or during the cycle sewing of buttonholes that are different in size. The double-acting stepping motor type knife mechanism is free from the faulty dropping/returning of the knife. The knife suports sewing lengths of 41mm at the maximum. In addition, knife mechanisms for 70mm and 120mm are optionally available.
