1. MECHANICAL DESCRIPTIONS
HE-800A
14
1-10-1. Upper thread scissors
1. An opening cam (3) is attached to the opening cam bracket (2) that is secured to the feed arm (1) (Figure A).
After sewing starts, the feed arm (1) moves in the direction of the arrow (forward).
2. When upper thread trimmer M (4) touches against the ridge line on the opening cam (3), the upper thread
trimmer gradually starts to open (Figure B). At this time, section D of the opening cam (3) fits into the upper
thread trimmer assembly (5) so that the upper thread trimmer assembly (5) cannot move in the direction of
arrow C.
Figure A
Figure B
4061Q
4060Q
