Important Safety Instructions - JUKI LBH-1790AB Manual De Instrucciones

I. IMPORTANT SAFETY INSTRUCTIONS
1) Before putting your sewing machine in operation, be sure to read this Instruction Manual as well as
the Instruction Manual and Cautions for Safety for the LBH-1790A without exceptions.
2) The contents included in this Instruction Manual only cover the features of the newly developed LBH-
1790AB shorter-thread remaining type which differ from those of the LBH-1790A. (The items which are
not contained in this Instruction Manual are described in the Instruction Manual for the LBH-1790A.)
3) To use the LBH-1790AB, be sure to select "With the shorter-thread remaining function" with the mem-
ory switch. (If the sewing machine is operated using the program which does not support the function
or selecting "Without the shorter-thread remaining function", the cloth trimming knife will not operate at
the correct position.)
II. SPECIFICATIONS
Main specifications of the LBH-1790AB computer-controlled, lockstitch, buttonholing machine (shorter-thread
remaining type)
1. Adjusting the bobbin thread tension
❷
❶
Turning tension adjust screw ❷ clockwise will increase bobbin thread tension, and turning it counterclock-
wise will decrease the tension.
Adjust the bobbin thread tension to lower for synthetic filament thread, and to higher for spun thread. The
thread tension is higher by approximately 0.05N when the bobbin case is set to the hook since idle-pre-
vention spring is provided.
Maximize the bobbin thread tension as long as stitching failures (such as thread breakage
and stitch crest formation fault) do not occur. The higher the bobbin thread tension is set,
the shorter the remaining length of the bobbin thread will become.
Subclass
Buttonholing of cloth such as men's shirts, blouses,
Major application
work uniforms, ladies' wear, etc.
Buttonholing size
Adjust the bobbin thread tension as given below when the bobbin
thread is pulled up at the position where thread slit ❶ of bobbin case
comes up.
Purl stitch 0.05 to 0.2N
Whip stitch 0.15 to 0.3N
– 3 –
B
Standard : Max. 4 mm
Knife size used :
6.4 to 22.2 mm (1/4' to 7/8' ※)
Buttonholing sewing length
Standard : Max. 25 mm
※ Since the shorter-thread remaining
type model is equipped with the
"Type 1" presser foot, the knife
size is limited to 7/8'. (The throat
plate supports the knife size up to
1 inch.)
To such an extent that bobbin case
quietly comes down when holding
thread end coming from bobbin case
and shaking it quietly up and down.
To such an extent that bobbin case
barely comes down when holding
thread end coming from bobbin case
and shaking it somewhat strongly.