MODELS 4T & 5T
The following additional equipment is supplied for use on TELESCOPIC Cranes:-
(f) Spring operated Recoil Drum assembly.
(g) Rotary Flexible Drive.
The Recoil Drum assembly is used to transmit the telescoping movement of the boom to the Control Box. A wire
cable, attached at one end to the boom head, is passed down the boom through suitable guides and is wrapped round the
drum which is spring loaded to keep the cable taut. Rotation of the drum, during telescoping, is geared through a chain
drive and gear box to the Rotary Flexible Drive which connects with the Control Box. Within the Control Box, a lead screw
is built in to the actuating arm (miniature boom) and is driven by the Rotary Flexible Drive, accurately positioning the slide
block in proportion to the boom length. The actuating arm is marked with a scale indicating the length of boom extended.
There are no further adjustments to make on Units on Telescopic Cranes. In this case, all the instructions given in the
previous pages apply, especially those with reference to the use of the correct cam to suit the working condition of the
crane. In most cases, when working with the main boom, it is only necessary to change the cam if the number of parts are
changed. Use of the manual section and jib also requires the cam to be changed.
The Radius Scale, showing the working radius of the crane, is standard on all Units supplied for Telescopic
Cranes and must be changed when working with Manual Extension and/or Jibs.
NOTE:- When using the jib or manual extension, the ratings are proportional to angle. Consequently, the wire from the
recoil drum must be fastened to the place provided on the base section.
MAINTENANCE. Models 4, 5 & 6.
Dynamometer. Clean out any clogged grease and dirt, especially adjacent to the center roller, "U"-shaped block and Load