TYM T233 HST, Service Manual

Page: 169 / 232

3.2 OPERATIONS
1) DOWN position
The fluid from port B pushes up stop ring (9)
of poppet(10) until the ring comes into
contact with adjust screw(6),as it reaches
chamber(R). Consequently,the extent choke
(C) is opened is determined by the
positioning of adjust screw (6):that is,when
adjust screw(6) is screwed in clockwise,the
opening of chock(C) decreases and the
lowering speed of the lift arm slows
down;whereas the opening of choke(C)
increases and the lowering speed of the lift
is accelerated when the adjust screw is
unscrewed counterclockwise.When the
adjust screw screwed in completely,the
poppet comes into contact with body seat(S)
and the choke is closed completely,so the
lift arm stops.
2) Up position
The flow port A,overcoming the force of
spring(11),pushes up poppet (10) and
choke(C)is fully opened regardless of the
position of adjust screw(6).Thus the fluid
flows to port B and the cylinder,which
results in raising the lift arm.
9-8
Fig. 9-7 Down position
Fig. 9-8 Up position