Manitowoc 3900W - Page 83

MANITOWOC ENGINEERING CO.
division of The Manitowoc Company, Inc.
Manitowoc, Wisconsin 54220
AUTOMATIC BOOM STOP-MAXIMUM BOOM ANGLE
(MECHANICAL OVER AIR)
PURPOSE
This Folio describes operation and adjust-
ment of the "air controlled" automatic boom
stop for the models listed in Figure 3.
OPERATION (FIGURE i AND 2)
The automatic boom stop is a protective
device which limits the maximum angle
(Figure 3) to which the boom can be raised.
I. When the boom is below the maximum boom
angle, the "quick-as-a-wink" valve is
in the open position. Air from the up
port of the boom hoist control valve
is, therefore, free to flow through the
"quick-as-a-wink" valve for normal boom
up operation.
2. When the boom is raised to the maximum
boom angle, the boom butt (crawler
machine) or the telescopic boom stop
tube (RINGER) contacts the control rod.
Control rod movement causes the lever
to close the "quick-as-a-wink" valve.
In this position, air from the up port
of the boom hoist control is blocked,
and the "quick-as-a-wink" valve ex-
hausts the air pressure in the air line
to the boom hoist control cylinder.
This action causes the cylinder to re-
lease the boom up clutch (or shift hy-
draulic pump to neutral), and the boom
automatic boom hoist brake applies to
stop the boom.
INSTALLATION PRECAUTIONS
i. Always install the "quick-as-a-wink"
valve with the IN port toward the front
of the machine (see Figure 2).
2. Connect the air line from the boom hoist
control (UP port) to the IN port of the
"quick-as-a-wink" valve.
Connect the air line to the boom hoist
control cylinder to the OUT port of the
"quick-as-a-wink" valve.
WAFIN,ING INCORRECTLY PIPED AIR LINES I
AT THE QUICK-AS-A-WINK" VALVE WILL RESULT J
IN MALFUNTION OF THE AUTOMATIC BOOM STOP I
AND MAY RESULT IN COLLAPSE OF THE BOOM. I
BOOM HOIST
CONTROL CYL.
AT CLUTCH OR
AT HYD. PUMP
DOWN
BOOM ~ i
HOIST ~ ~p
CONTROL ~"BOOM DOWN"
M J I~AIR LINE
OUT I-- "BOOM UP"
'-~~IN --AIR LINE
AUTOMATIC
BOOM STOP
CONTROL
TO BOOM HOIST AUTOMATIC
BRAKE (MACHINE W/HYDRAU-
LIC BOOM HOIST ONLY)
FIGURE i. SIMPLIFIED AIR PIPING
(Refer to "Maintenance Section" of
SERVICE MANUAL for exact air piping
of Boom Hoist System)
MAINTENANCE (FIGURE 2)
r=Llou~c=±±y squirt = few ~o ~ ..... ~ #
motor oil on the "quick-as-a-wink"
valve at the points where the valve
sleeve slides on the valve body. Apply
grease to the control rod (where it
slides on the bracket) to all pivot
pins, and to each spring.
2. At least once weekly check that the
automatic boom stop assembly stops the
boom at the angle specified in Figure
3. If not, replace defective parts
and/or readjust the assembly.
(Cont'd.)
6-29-74 (As Rev. 2-ii-81) AUTO. BOOM STOP FOLIO 828-i
395143