6
Description of components
DESCRIPTION OF BRAKE COMPONENTS
1-17
When the vehicle is loaded, the distance
between the chassis frame and the axle is
reduced, so that control lever (5) is twisted. That
is why the specially shaped disc (6) forces
piston sleeve (7) upwards. The input pressure at
port 4 forces piston (13) downwards again, until
valve (14) makes contact with piston sleeve (7).
Because the downward movement of piston (13)
is smaller (higher position of the piston sleeve),
more than one section of the diaphragm (12) will
be released from the ridges (20) in the valve
body. As a result, the effective surface of the
diaphragm remains smaller, so that in chamber
(15) a higher pressure is required to move the
diaphragm with piston (13) upwards and to close
inlet valve (14).
When a vehicle carries no load, piston sleeve
(7) is in its lowest position. The input-braking
pressure at port (4) forces piston (13), which is
attached to diaphragm (12) and wings (19),
downwards until valve (14) comes into contact
with piston sleeve (7). The movement of piston
(13) causes diaphragm (12) to become released
from the ridges (20) in the valve body, thus
increasing the effective surface of the
diaphragm. Since in this position the effective
surface of the diaphragm exceeds the effective
surface of piston (13), even a slight pressure in
chamber (15) will suffice to move the diaphragm
with piston (13) upwards, and to close the inlet
valve.
3
ǹ 0006