Crown Equipment Sit-down Rider Lift Truck SC 4500 Series - Manual (Page 5)

SC 4500 Series Technical Information
panel is conveniently located
with all test points, control
fuses and central wiring for
easy troubleshooting.
Three modes of performance
can be selected to accommo-
date operator experience or
application requirements.
e-GEN™ Braking System
Variable regenerative motor
braking is optimized and
assisted with electric friction
brakes, eliminating maintenance
associated with typical wet,
disk or drum and shoe style
brakes. The appropriate amount
of stopping force is applied to
match operator brake input
and the current operating
conditions of the truck.
The closed loop Access 1 2 3 ®
traction control will keep the
truck static until a travel input is
requested, even when operating
on a grade.
Automatic electric parking
brakes activate when the
operator leaves the seat, a
travel input has not been
requested or battery power
has been disconnected.
Proportional Rack and
Pinion Steering System
Hydrostatic power steering uses
a large, totally enclosed rack and
pinion gear assembly.
The steering geometry is
matched to the controller to
deliver smooth steering at all
angles. The advantage is less tire
scrubbing which extends tire life.
Both motors receive power, even
in the tightest turns. This helps
the truck to accelerate, turn and
maneuver even from a full turn
start position.
Cornering speed control
regulates the drive motor’s
output by the turning degree
of the truck. The advantage is
smooth, stable steering which
may increase operator
confidence and productivity.
Large, (15" diameter) dual steer
wheels provide good traction
and stability.
Hydraulics
The hydraulic system provides
continuous filtration. A heat
stabilized polymer hydraulic
tank is free from contamination
and retains strength over a wide
range of temperatures. Hydraulic
attachments can be added easily
in the field using modular valve
bodies. Hydraulic valve handle
actuation is precise and oil
is controlled using metered
spool valves.
Ram displacement type lift
cylinders and two double
acting tilt cylinders are
Crown-manufactured. All
rams and piston rods are
hard chrome plated to
reduce pitting and extend
cylinder packing life. O-ring
face seal fittings are used
to eliminate leaks.
Mast Assembly
Crown-manufactured mast
assembly utilizes a “flush-face”
interlocked I-beam design to
improve visibility and save truck
length. Roller bearing studs are
welded on both sides of the rails
for maximum strength and roller
bearings are canted to run in the
thick cross section of the rail. Tie
bars wrap around the rails for
added strength and to resist
off-center load forces.
“In-line” hose routing opens up
visibility. Cylinders are placed
to the sides to create a high
visibility design.
The mast has four points of
attachment to the truck for good
load force distribution. Two
mounting points are at the
frame, where tilt cylinders attach.
Tilt cylinders use spherical
bushings to resist off center load
distortions. Two large diameter
trunions secure the mast to
the drive units.
Drive Units
Two independent double
reduction gear drives offer
22.5 to 1 gear reduction.
The first reduction uses spiral
bevel gears for low noise and
efficiency. The second reduction
uses helical gears.The drive unit
gears are constantly lubricated
in an oil bath.
This time proven design is quiet
and reliable, providing years of
trouble-free service.
Carriage
An ITA Class II carriage is stan-
dard. An optional hook type ITA
sideshifter or other attachments
are easily added. Optional fork
lengths are available.
Other Options
1. Audible travel alarm
2. Flashing lights
Safety considerations and
dangers associated with
audible travel alarms and
flashing lights include:
• Multiple alarms and/or lights
can cause confusion.
• Workers ignore the alarms
and/or lights after day-in and
day-out exposure.
• Operator may transfer the
responsibility for “looking out”
to the pedestrians.
• Annoys operators and
pedestrians.
Other Options Available
Contact your local Crown dealer.
Dimensions and performance
data given may vary due to
manufacturing tolerances.
Performance is based on an
average size vehicle and is
affected by weight, condition of
truck, how it is equipped and
the conditions of the operating
area. Crown products and
specifications are subject to
change without notice.