AC MUM0096 rev. 07 - 25 -
MR21
17.2.3. ADJUSTMENT OF BRAKING TORQUE
The braking distance depends on the compression of the brake’s
springs, which are adjusted to the equipment’s characteriscs and
in conformity with EN81.20-50 .par. 5.9.2.2.2.1, explained below:
This brake must be capable of stopping by itself the machinery
with cab travelling downhill at a nominal speed and with a loading
capacity increased by 25%. Under these condions, the cab’s
deceleraon must not be greater than that obtained by intervenon
of the parachute safety device or by impact on the shock absorbers.
All of the brake’s mechanical elements that contribute to exercising
the braking acon on the braking surface must be installed in pairs.
If one of said elements does not work because of a fault, braking
should be connued to slow down, stop and keep the cab sll that
travels downhill at a nominal speed with a load equal to the nominal
load capacity and uphill without a load (empty).
It must be taken into consideraon that, following the lining’s wear
level, the springs’ compression level tends to decrease, reducing its breaking capacity. In this case, an
increase of the spring’s pre-load as adjustment, is considered as being an error, given the fact that the
operaon must be associated also to an adjustment of the stroke.
If this procedure is not done correctly, the brake system may not work correctly.
The braking torque is adjusted when the cab is empty.
- Repeat the same steps for both brake shoes:
- Unscrew the locknuts (4).
- Check the braking distance.
- If the braking distance is too short, loosen the spring by turning the nut (3). If it is too long, ghten
the spring again by turning the nut (3).
- Once the braking distance has been adjusted correctly, check that the springs are of the same
length. Secure the adjustment using the locknut (4).
When the adjustment is nished, we recommend checking that the springs are not fully compressed
and that the provisions set out in EN81.20-50 par. 5.9.2.2.2.1 have been veried. In the event that the
springs are fully compressed, bring them back to the L level shown in the Picture and proceed again with
the stroke regulaon cycle and braking moment.
4
3
L