March 2008 "3072RT / 3772RT / 3772RT HD" Service & Parts Manual - ANSI Specifications
Page 1-18
LEFT SIDE
Counterbalance
Valves
Lift
RED/BLU
Lift Relief Valve
Lift Port
Orifice Under Fitting
3 Way Solenoid
Operated Hydraulic
Spool Valve
PLATFORM LIFT CIRCUIT
Note: Refer to
Hydraulic Manifold
and
Relief Pressure Adjustment Procedure
.
Refer to
Section 3
for Remove and Replace instructions.
• The lift system uses the hydraulic pump to obtain proportional lifting function controlled by
the lift valve and proportional valve.
• Lowering is single speed controlled by the holding valves on the lift cylinder(s) and regu-
lated by a fixed orifice located on the lift cylinder(s).
• Platform capacity is limited by a hydraulic relief valve in the lift circuit. (Refer to Machine
Specifications or the Hydraulic Schematic for proper setting).
Lift Cylinder
Note: Refer to
Cylinder Repair
.
3072RT
One (1) single acting type hydraulic cylinder.
The cylinder has an integrated 2-position, 2-way solenoid operated platform lower valve for hold-
ing the platform in position. The
valve is also externally actuated
via a cable for manually lowering
the platform.
3772RT
Two (2) single acting type hydrau-
lic cylinders.
Each cylinder has an integrated
2-position, 2-way solenoid oper-
ated platform lower valve for
holding the platform in position.
The valves are also externally
actuated via a toggle switch for
manually lowering the platform.
The normally closed holding
valve prevents retraction of the
cylinder rod should a hydraulic
line rupture or a leak develop
between the cylinder and its
related control valve.
To Next Page
Loading...
