Theory Of Operation - Zephyr ZGS-11000-2 v2 Operation And Maintenance Manual

Manual RHGSE Operation and Maintenance Manual

5.0) Theory of Operation

The wire rope is paid off of the helicopter hoist and is wrapped three times around the
capstans and the rescue hook is positioned in a rotating tub. A spooler holds the rescue hook and
establishes the starting position of the wire rope to achieve an even storage of the wire rope in the
rotating tub. The wire rope is held firmly in the special grooving of the capstans by two tension roller
assemblies. The tension roller assemblies are held open by pins when installing and removing the
wire rope from the capstans. The RHGSE is manually operated by rotating the crank handle when the
helicopter hoist is extending, and a band clutch applies a back torque on the capstans to develop a
heavy load in the wire rope when the helicopter hoist is retracting. The hand crank handle is self
disengaging so that when the RHGSE is used in the retracting direction the crank handle does not
rotate. The rotating tub is mounted to a clutch that is adjustable to compensate for the taper in the
spooler and tub. A set of pads installed in the Lubridryer clean the wire rope, and provides lubrication
via an oil reservoir if required, the flow of oil from the reservoir can be started and stopped by a shut
off valve. When the wire rope is to be cleaned using fresh water, the tub is filled with water and
compressed air can be fed to a dryer located below the oiler to dry the wire rope as it is retracted from
the rotating tub full of water. A ball valve has been added to allow the air supply to be shut off when
not being used. Air pressure required is 30 psi minimum. After the cleaning is finished the tub is easily
drained via a removable plug. The RHGSE can be used with different size wire rope by changing the
capstans.
The RHGSE weighs 580 lbs dry and is transported to the helicopter via a tow handle that is
held in the upright position by a set of spring clips attached to the base. The tow handle can be
attached to either side of the RHGSE as desired. A transparent cover is provided to enclose the
capstans while in use. An adapter is provided to facilitate installing a new cable into the rescue hoist.
The RHGSE consists of:
Load indication system
Load application lever
Load adjusting knob
Self disengaging hand
crank
Zephyr International llc
Lubricating and drying system
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ZOM-11000-2 v2 rev E
Tow handle that can be
attached to two locations
Upper and lower capstan rollers
Rotatub
Spooler
Heavy base mounted
on three casters
United States Patent # 7,429,031 B1