Upper Shaft, Lower Shaft And Rotary Hook Mechanism - Brother LH4-B800E Service Manual

1. MECHANISM DESCRIPTION

1-2. Upper shaft, lower shaft and rotary hook mechanism

i
u
1. When the machine pulley q is turned in the direction of the arrow, the rotation is transmitted to timing pulley U e
that is secured to the upper shaft w.
2. The timing belt r is attached to timing pulley U e, and it accurately transmits the rotation of the upper shaft to the
timing pulley t.
3. The timing pulley t is secured to the lower shaft y, and it transmits the rotation to the rotary hook joint u that is
secured to the end of the lower shaft y.
4. The rotary hook i is secured to the rotary hook joint u and rotates fully together with the rotary hook joint u.
1 - 2
r
e
w
y
t
LH4-B800E
Direction of
rotation
q