CD397-Oper
Operation - 1 - 3
August 2018 (Rev B)
Operation
Mobile Belt Loader Model 660-28
Section 1
Operation Manual
When a manual lever is actuated, the lever mechanically shifts the spool valve position, porting fluid to
that side of the lift cylinder to be pressurized. Spool Valve movement also opens a channel for the non-
pressurized portion of the lift cylinder piston to allow unpressurized oil to return to the hydraulic oil
reservoir through port on the valve manifold assembly and the return line hydraulic filter.
Likewise, when the conveyor motor control valve is actuated in either direction, its electric solenoid shifts
the spool valve position, porting fluid to the forward or reverse side of the conveyor motor/CBV assembly.
Spool valve movement also opens a channel for the non-pressurized portion of the conveyor motor/CBV
assembly to allow unpressurized oil to return to the hydraulic oil reservoir through port on the valve
manifold assembly and the return line hydraulic filter.
With the manual control levers in their neutral state, the front and rear cylinders are locked in the current
position by load holding valves, located on their respective cylinders.
1.3.3.3
Emergency
Pump
The 660 belt loader is equipped with a back up emergency pump. The pump may be used to lower the
conveyor to the normal down position, or to retrieve luggage that may be on the belt at the time of motor
failure. It is not to be used to load luggage into the hold of the plate at any time. The emergency hydraulic
pump should only be operated when the regular conveyor motor is off or not operating. Refer to
Operation, 2.4 Preventive Maintenance.
1.3.4
Conveyor
Belt
The conveyor is fabricated from structural shapes and formed steel, and is attached to the chassis
through front and rear lifting arms.
The front cylinder, supporting the front lifting frame, raises the conveyor to 170 in. (431.8 cm).
The conveyor frame is 34 in. (86.4 cm) wide. The conveyor belt is 24 in. (60.96 cm) wide and is supported
by 2 in. (5.08 cm) diameter rollers and is hydraulic motor-driven through a roller chain reduction. The front
roller is mounted in a flange block with a screw-adjustable take-up that allows 6 in. (15.24 cm) of
adjustment.
Crowder rollers under the support rollers direct the return side of the belt into areas where required
clearances around fixed components is maintained. An inverted angle iron track on the lower forward
section of the conveyor maintains lateral stability through V-shaped rollers mounted to the front lift frame.
The motor is equipped with a worm gear and double reduction sprocket drive, and an electric brake to
hold the load when not in motion.
CAUTION:
The emergency pump should only be operated when the regular propulsion engine is
OFF or NOT operating.
Engaging the emergency pump for more than one minute will cause to overheat. If
emergency procedures cannot be completed within one minute, disengage and allow
the pump to cool for at least 10 minutes before re-engaging. Failure to comply may
result in vehicle damage.
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of
American
Airlines
