the HOLD position. The piston is backed off and the brake released by introducing hydraulic pressure into the
(a) Spade operation. The spade is actuated by two, single-end rod, double-acting hydraulic cylinders.
These cylinders retract to raise the spade, and extend to lower it. When the spade control valve is placed in
the RAISE position, hydraulic pressure is introduced in front of the cylinder pistons and bled off behind them.
The piston rods then retract and actuate the crank arms to raise the spade. When the spade control valve is
placed in the LOWER position, hydraulic pressure is introduced behind the pistons and bled off in front of
them. The piston rods then extend and actuate the crank arms to lower the spade. Placing the spade control
valve in the HOLD position traps all hydraulic fluid in the lines, thus preventing the spade from moving either
up or down.
(b) Cable level winder assembly operation. The cable level winder assembly consists of a traversing
cylinder; a stationary, double-end piston rod; a cable level winder valve, and mechanical linkage. As the
cable is reeled in, it exerts a force on either the right or left side of a guide through which it passes. This force
is transmitted to a lever which positions the cable level winder valve. The valve then directs hydraulic pressure
to either the right or left side of the traversing cylinder, causing it to move and wind the cable evenly.
(c) Hydraulic motor operation. The hydraulic motor is a reversible, vane-type motor equipped with two
identical inlet-outlet ports. Hydraulic pressure introduced at either of these inlet/outlet ports is forced through
the vanes of the rotor, thus turning the rotor and the shaft which is splined to it. The direction in which the
motor rotates (i.e., clockwise or counterclockwise) depends on which inlet/outlet port the hydraulic pressure was
introduced, and is controlled by means of the main winch combination control valve mounted on top of the
(d) Winch gear train operation. When the main winch control valve is in the INHAUL position, the hydraulic
motor rotates in the clockwise direction (fig. 1-6) and drives the winch bevel gear and pinion shaft, causing
them to rotate clockwise also. (Gear direction of rotation is determined by viewing the winch from the brake
assembly side). The pinion gear is splined to the pinion shaft and thus drives the shaft in the same direction.
As the pinion shaft rotates, the geared end of the shaft engages the low speed gear and the pinion gear
engages the high speed gear, both of which rotate freely around the brake shaft. Between the shaft is the gear
clutch. The external teeth of the gear clutch are meshed with the internal teeth of the gear coupling. This
coupling is positioned either left or right in order to couple the gear clutch with either the high or low speed
gear, thus causing the break shaft to rotate in the counterclockwise direction. The splined end of the brake
shaft drives the brake drum assembly while the geared end of the shaft meshes with and drives the
countershaft gear which is spline-mounted to the countershaft, in the clockwise direction. Also splined to the
countershaft is a pinion. The pinion engages the drum gear assembly, thus causing the cable drum to rotate in
the counterclockwise or INHAUL direction. Placing the main winch control valve in the PAYOUT position
causes the hydraulic motor to rotate in the counterclockwise direction. All gears then rotate in the opposite
direction from that described above, and the cable drum rotates in the clockwise or PAYOUT direction.