Manitowoc Grove GRT9165, Service Manual

Page: 147 / 302

Grove
Published 10-01-2020 Control # 699-00
4-9
GRT9165 SERVICE MANUAL BOOM
MECHANICAL EMERGENCY UNLOCKING
AND LOCKING OF THE TELESCOPIC
SECTIONS
The mechanical emergency operation must be used
whenever the telescoping cylinder can no longer be moved.
For manual unlocking and locking of the telescopic sections,
a screw is inserted into each side in the locking pins. When
screwed in, the screw collapses the spring internal to the
locking pin, thus pulling the locking pin which pulls the
locking pin into the telescopic section and thus unlocks the
section.
The screw is unscrewed to lock the section manually.
The main boom is designed in such a way that the locks can
be operated in emergency mode from the outside for most
fixed lengths.
NOTE: If the telescoping cylinder is in the foot section of a
telescopic section, this telescopic section cannot
be locked or unlocked manually.
Prerequisites
The following prerequisites must be fulfilled before unlocking
a telescopic section manually:
• The telescopic section to be unlocked is attached to an
auxiliary crane with sufficient load bearing capacity and,
in this way, is secured against independent retraction.
Or
• The main boom is lowered into a horizontal position so
that the telescopic section is unable to retract
independently.
Maintenance
For manual unlocking, two capscrews (M8x110 Grade 8.8)
are supplied for all pins and sections (Figure 4-9):
• 125 mm length for telescopic section 5.
• 140 mm length for telescopic section 4.
• 170 mm length for telescopic section 3.
• 200 mm length for telescopic section 2.
• 270 mm length for telescopic section 1.
You can only lock or unlock a telescopic section manually if
the recess (2, Figure 4-10) in the locking pin (1) no longer
engages in the telescopic section (3) above it.
Extend the telescopic section approximately 20 mm (0.79 in)
(with an auxiliary crane, forklift or other means of external
force). The locking pin (1) must be centered in the opening
and the recess (2) may no longer engage in the telescopic
section (3) above it.
Unlocking Telescopic Sections
When unlocking sections start with Tele 5 (fly) and work your
way in towards Tele 1 as far as possible. Unlock and lock
only one section at a time.
1. Remove the grease fitting from the bore hole (4,
Figure 4-10).
2. Insert a screw into the hole (4). The locking pin (1) is
retracted in the process. You can assist this process by
lightly hammering on the locking pins.
WARNING
Crushing Hazard!
Failure to follow these prerequisites could allow a boom
section to retract uncontrolled resulting in injury or
equipment damage.
FIGURE 4-9
270 mm
9515
Tele 5
Tele 4
Tele 3
Tele 2
Tele 1
200 mm
170 mm
140 mm
125 mm
FIGURE 4-10
2
1
9514
3
4