Brother HE-800A Service Manual page 21

1. When the pulse motor (1) operates, the gear (2) that is installed to the pulse motor shaft engages with the
presser driving arm (3) so that the guide bracket (4) moves along the guide shaft (5) and moves the presser
driving arm (3) in the direction of the arrow.
2. The presser driving arm (3) causes the presser foot lifter connecting rod (6) to move in the direction of the
arrow.
3. The movement of the presser foot lifter connecting rod (6) is transmitted via the knee lifter lever (7) to move the
upper thread trimmer driving link (8) in the direction of the arrow.
4. The driving lever roller (13) and ball bearing (14) that are installed to the ends of the trimmer driving levers (9)
and (10) by the shoulder screws (11) and (12) are linked to the cam groove in the upper thread trimmer driving
link (8) so that when the upper thread trimmer driving link (8) moves in the direction of the arrow, the trimmer
driving levers (9) and (10) operate.
5. When the trimmer driving levers (9) and (10) operate, the longitudinal feed arm (15) and trimmer driving arm
(16) that are secured to the trimmer driving levers (9) and (10) move in the direction of the arrow.
6. When the longitudinal feed arm (15) operates, the upper thread trimmer lever (18) that is attached to the
longitudinal feed arm roller (17) at the end of the longitudinal feed arm (15) moves back and forth.
7. When the trimmer driving arm (16) operates, the driving arm roller (19) that is installed to the trimmer driving
arm (16) rolls along the cam groove in the upper thread trimmer lever (18), and the upper thread trimmer lever
(18) rotates centering on the upper thread trimmer fulcrum shaft (20).
8. The setting plate (21) is secured to the end of the upper thread trimmer lever (18), and so the movement is
transmitted to the upper thread trimmer assembly (22) that is secured to the setting plate (21).
9. Upper thread trimmer M (23) that is installed to the upper thread trimmer assembly (22) comes into contact with
the work clamp, so that upper thread trimmer M (23) closes and cuts the thread.
HE-800A
1. MECHANICAL DESCRIPTIONS
4059Q
13