Oshkosh JLG 1500SJ, Руководство по обслуживанию и ремонту

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SECTION 4 - BOOM & PLATFORM
3121262 – JLG Lift – 4-1
SECTION 4. BOOM & PLATFORM
4.1 BOOM SYSTEMS
NOTE: For more detailed information concerning system adjust-
ment and operation, refer to Section 6 - JLG Control Sys-
tem.
Broken Cable Indicator System
The boom on this model is a 4 section proportionally driven
telescopic boom. The inner mid boom is driven directly by the
telescope cylinder. The outer mid and fly booms are each
driven by separate wire rope systems. Each rope system con-
tains redundant ropes that are capable of allowing the opera-
tor to unknowingly continue use of the machine with a single
rope failure. These kinds of failures with the extend ropes are
self revealing to the operator so proper action can be taken.
Failures within the fly extend ropes are self revealing as they
are exposed on the exterior of the boom where a broken rope
would be obvious. Failures within the outer mid ropes require
the addition of the Broken Cable Indicator System in order to
be self-revealing to the operator. This system uses a proximity
sensor to detect excessive movement of the sensed rope as
would be expected with a rope failure. A broken rope detec-
tion results in illuminating the Cable Break indicator on the
platform control panel. No restrictions are made to the func-
tionality of the control system. It is the responsibility of the
operator to take the appropriate action.
Platform Control Enable System
The platform controls make use of a time dependent enable
circuit to limit the time availability of “live” or enabled controls.
When the footswitch is depressed, the controls are enabled
and the operator has 7 seconds to operate any control. The
controls will remain enabled as long as the operator continues
to use any function and will remain enabled 7 seconds after
the last function has been used. While the controls are “live”,
the enabled light will be illuminated in the platform display
panel. When the time limit has been reached, the enabled
light will turn off and the controls will be “dead” or disabled. To
continue use of the machine the controls must be re-enabled
to start the timer system over again. This is done by releasing
all functions, then releasing and re-depressing the footswitch.
Transport Position Sensing System
The transport position sensing system uses the main boom
angle sensors, the main boom length sensor mounted in the
pivot end of the main base boom in addition to the boom
length switch mounted on the platform end of the main base
boom and length switches mounted to the jib fly boom to
sense when the main boom and jib boom are in the position
associated with high speed travel. Above transport angle is
recognized when one main boom angle sensor reads more
than 6° in relationship to the turntable and resets to within
transport position when both main boom angle sensors read
less than 4° in relationship to the turntable. Transport length is
recognized when the main boom length switch and main
boom length sensor read less than 1 ft (0.3 m) extension for
the main boom. In addition the jib boom length switches must
indicate fully retracted and the jib boom must be locked in line
with the main boom. During failures of either the main boom
length switch or the main boom length sensor the main boom
transport length will be determined by the remaining sensor
or switch. In addition for a failure either jib boom length
switch, jib length will be determined by the remaining switch.
This system is used to control the following systems:
• Beyond Transport - Drive Speed Cutback System
• Drive/Steer - Boom Function Interlock System (CE Only)
• Jib Stow System
• Axle Extension System
• Oscillating Axle System
Beyond Transport - Drive Speed Cutback System
When boom is positioned beyond the Transport Position, the
drive motors are automatically restricted to their maximum
displacement position (slow speed).