MODELS 4T, 5T and 6T.
These instructions are additional to those given for Models 4, 5 and 6 in Data Sheets. The complete instructions given for
those models apply also to units for use on Telescopic Boom Cranes.
The telescopic action of the boom must be transmitted to the Control Box to give a true indication of the working radius, as
well as the Safe Working Load for that radius, as the boom ex- tends or retracts.
The additional parts supplied are as follows:-
1. Spring Recoil Drum.
2. Stainless Steel Wire Cord. (0.080" dia.)
3. Rotary Flexible Drive.
Certain brackets and pulleys. are also required, according to the type of crane although the general method of installation
is common on all Telescopic Cranes on which the Weighload Model 4T, 5T or 6T Indicator is fitted.
INSTALLING THE SPRING MOTOR RECOIL DRUM.
The most suitable position for this drum assembly is on the superstructure under the boom hinge, mounted so that the wire
cord, stowed on the drum periphery, can be passed up the entire boom without hindrance or severe deflection. (see
"Installing the Boom Wire Cord"). The other factor governing the position of the Drum Assembly is the routing of the
Rotary Flexible Drive from the Drum Gear Box to the Control Pox (see "Installation of Rotary Flexible Drive").
Care must be taken that the Drum Assembly is clear of all obstructions, especially the boom hoist cylinders, during
When the most suitable position has been ascertained, the Drum Assembly can be bolted in position with 1/2" dia. bolts,
either directly to the crane structure or to a subplate specially made for the purpose.
If it is necessary to reverse the rotation of the spring, this Is achieved as follows:-
a. Remove all screws from the large cover on the spring housing and carefully lift off the cover.
b. If the spring is Not fitted with a retaining band, slide a suitable band over the outside diameter to retain it in
its present shape, winding the drum to tighten the spring to allow this band to be fitted.