Manual RHGSE Operation and Maintenance Manual ZOM-11000-2 v2 rev E
Zephyr International llc
Page 28 of 40 United States Patent # 7,429,031 B1
Rotatub
Spooler
7.14) Adjustable platen adjustment
In order to accommodate the variation in speed of the cable as it wraps in the Rotatub and around the
Spooler a simple clutch is used. The clutch is lubricated with Mil-G-81322 grease. If the clutch is too
tight the cable will ride up the spooler too quickly and may come out of the Rotatub. If it is adjusted too
loose then the cable will back up in the Rotatub and not wrap up on the spooler properly. In addition if
the cable is wrapped too tightly around the spooler it can not relax in the Rotatub thus trapping the
twist between the RHGSE and the Rescue hoist.
The above pictures shows that as the cable is wrapping at the bottom of the spooler it is going at
maximum speed which is the same speed as it is coming off the capstans. As the cable starts to climb
up on the spooler it starts to slow down due to the reduced diameter. But the Rotatub must actually
go faster in order to collect the cable and not allow it to back up in the Rotatub. Therefore the clutch is
slipping the most when the cable is at the bottom of the spooler. If the clutch does not slip properly the
cable is forced up the spooler and there is less room on the spooler to collect all the cable.
To adjust the platen torque, remove the Rotatub and the Spooler, remove the (4) lock nuts and
washers and lift the rotatub off of the platen. Check the adjustment by using a spring scale to rotate
the platen clock wise while pulling tangentially to the bolt circle. The clutch is set properly when the
torque required is such that with a spring scale attached
(shown below)
to the attachment screws as
shown, the platen slips with a force of 2.2-2.7 kg or 5-6 lbs of load applied. Note the brake must be
applied in order to check the clutch slippage.
(4)Adjustment screws
