The control pressure connection gets hydraulic control pressure from the sync lock valve (SLV). Hydraulic pressure from the sync lock valve releases the sync lock when there is a reverse thrust command.
EFFECTIVITY
BEJ ALL

Manual Drive Unit
A 3/8 inch manual drive permits you to manually extend and retract the thrust reverser sleeve for maintenance. The manual drive has an internal clutch which limits the input torque to a maximum of 110 inch-pounds (12.4 Newton-meters).
Proximity Sensor and Target
The proximity sensor is mounted in a flange on the body of the manual drive unit. The proximity sensor uses a target mounted on the lock release lever to send sync lock position data to the thrust reverser indicating and fault detection system. The signal from the sensor will indicate target NEAR for the lock position and target FAR for the unlock position.
See section 78-36 for more information.
Operation
When hydraulic pressure is applied at the control pressure connection, the internal sliding jaw in the unit moves to the unlock position and disengages the rotating jaw which unlocks the sync shafts. The sliding jaw also turns the lock release lever and target away from the proximity sensor to indicate the unlock position. With hydraulic pressure, a lockout piston moves to hold the sliding jaw in the unlocked position during the extension of the thrust reverser sleeves.
78-34-00

Page 17 D633W101-BEJ May 05/2003

TRAS -SYNC LOCK/MANUAL DRIVE UNIT

When hydraulic pressure is removed at the control pressure connection, the lockout piston is spring-loaded to return to it’s usual position which releases the sliding jaw. Without hydraulic pressure, the sliding jaw is spring-loaded to return to the locked position and to engage the rotating jaw which locks the sync shafts. This causes the lock release lever and target to turn toward the proximity sensor to indicate the lock position. When the jaws are engaged, the sync shafts will not turn. This is the reason there is a time delay in the control circuit for the sync lock valve to allow the thrust reverser sleeves to retract to the stow and lock position before the sync lock jaws engage.
For ground maintenance, move the lock release lever away from the proximity sensor and use the lock pin to hold the lever in the unlock position. Insert a 3/8 inch square drive in the manual drive unit and push into the unit to engage the internal pinion gear with the bevel gear on the rotating jaw. You must maintain the inward force against a spring force to keep the pinion gear engaged as you turn the square drive to extend or retract the T/R sleeves. The clutch in the manual drive will release to prevent damage to the actuation system if you exceed 110 inch pounds (12.4 Newton meters) of torque. When you remove the square drive, the pinion gear is spring-loaded to disengage the bevel gear.
Training Information Point
　
中國航空網 www.k6050.com
航空翻譯 www.aviation.cn
本文鏈接地址：777 AMM 飛機維護手冊 發動機排氣 Engine Exhaust PW 777 AIRCRAFT MAINTENANCE MANUAL(31)