Bh Lever Switch Load - Brother XM3700 Service Manual

Adjustment
[Standard]
When the BH lever is pushed from the rear to the front, the switching road of the position
should be 0.5 to 1.5 N (50 to 150 gf). And when the BH lever is pushed from the front to
the rear, the switching road of the position should be 0.5 to 3.0 N (50 to 300 gf).
[Adjustment]
1. Remove the face plate, the pattern selection dial and the front cover.
2. Pull down the BH lever to the downmost.
3. Switch the position to the rear side by pushing the BH lever from the front to the rear.
4. Push the BH lever from the rear to the front with a tension gauge, and measure the load that switches to the front side.
*Key point
• Measure the load while keeping the tension gauge in a horizontal position.
5. Loosen the screw 1 of the BH adjusting plate.
6. Adjust the load of the BH lever that switches from the rear to the front side by moving the BH adjusting plate
up and down.
*Key point
• When the BH lever is pushed from the rear to the front, the switching road of the position should be 0.5 to 1.5 N (50 to 150 gf).
*Key point
• Move up the BH adjusting plate. → The switching road is light.
• Move down the BH adjusting plate. → The switching road is heavy.
7. Tighten the screw 1 of the BH adjusting plate to secure the BH adjusting plate to the arm bed.
8. Switch the position to the front side by pushing the BH lever from the rear to the front.
9. Push the BH lever from the front to the rear with a tension gauge, and measure the load that switches to the rear side.
*Key point
• When the BH lever is pushed from the front to the rear, the switching road of the position should be 0.5 to 3.0 N (50 to 300 gf).
1
XC2277001
BH lever

BH lever switch load

Screw, Pan (S/P washer)
M4X8DA
Push-pull gauge (5 N)
0.5 - 1.5 N
(50 -150 gf)
Push-pull gauge
4 - 34
1
BH adjusting plate
BH lever
0.5 - 3.0 N
(50 - 300 gf)
Push-pull gauge