Operator`s manual

MAINTENANCE MANUAL
SECTION 4
4. LADDER ASSEMBLY
4.1 GENERAL DESCRIPTION
The Ladder Assembly consists of a Turntable, a Substructure, three Ladder Sections, a Ladder Control
Console, four Outriggers and two Outrigger Control Panels.
The Turntable is supported by the truck Substructure which is positioned over the rear wheel assembly
(see Figure 4-1). The Turntable assembly consists of a heavy gauge steel plate and a three-part bearing
surface of high quality cast steel. One part of the bearing is bolted to the Turntable, the second to the
ladder Substructure. The third part, the pressure ring, turns on 260 balls located in twin raceways
between the Turntable and the Substructure. The Turntable is rotated horizontally through a worm gear
assembly, driven by a hydraulic motor (see Figure 4-2, number 1) .
A pair of heavy steel castings on the Turntable form a cradle to support the weight of the ladder sections
and allow ladder Section One to pivot on its base under control of the elevating jacks (see Figure 4-3,
number 1). A pintle pin (2) attaches ladder Section One to the cradle and allows it to rotate from -3
degrees through 75 degrees. The elevating jack cylinders are fitted with pistons which are connected
through piston rods to pivot points on the Turntable (4).
Section One of the ladder is bolted to the Ladder Support Assembly (see Figure 4-3, number 5) which is
connected to the elevating jack cylinders.
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