Hydraulics
9803/8500
Issue 2
Loader Valve - Lift Ram Operation
Lift
The illustration shows 'Loader Arm Raise' being
selected by the lift ram spool 1.
When the lift spool 1 is selected to lift, oil flows to
the lift ram 2 to raise the loader arm. As the arm
rises, oil is forced out of the compensating ram 3.
The oil cannot flow past the crowd ram spool 4 as
the spool is not selected, instead it flows to the
crowd ram 5. This has the effect of causing the
crowd ram to close in proportion to the loader arm
movement, automatically keeping the shovel parallel
to the ground.
The oil from the other side 6 of the crowd ram is fed
into the opposite side of the compensating ram at 7.
Should pressures generated in lines 8 and 9 rise
above the set pressure then the auxiliary relief
valves fitted at 10 will lift and dump pressure to tank.
Lower
Is a reverse of the above procedure.
5 - 4
5 - 4
Descriptions
Section E Section E
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