AFT SMALL CARGO DOOR SYSTEM -VENT DOOR AND VENT DOOR CAM
EFFECTIVITY BEJ ALL 52-35-00
Page 15
D633W101-BEJ Jan 05/2002
AFT SMALL CARGO DOOR SYSTEM -LIFT/LATCH POWER DRIVE UNIT, BUNGEE, AND LIFT CRANK
Purpose
The lift/latch power drive unit (PDU) supplies the force for these functions:
*
Move the door out of and into the latch position
*
Engage the lift lock cams with the lift pins.
The bungee is an overcenter device that makes the lift/latch torque tube moves to the limit of its rotation in either direction.
The latch crank lifts and lowers the door out of and into the latch (plug) position.
Location
The PDU is near the middle of the door above the lift/latch torque tube.
The bungee is on the center of the door, below the lift/latch torque tube.
The lift cranks are on the ends of the lift/latch torque tube.
Physical Description
The PDU has these parts:
*
A linear actuator
*
An electric motor
*
A manual drive input.
The bungee is a compression spring on a shaft.
One end of each latch crank attaches to the end of the lift/latch torque tube. The other end has a roller that fits into the latch tracks on the door cutout.
Functional Description
The electric motor moves the linear actuator. The manual drive can also move the actuator. The actuator moves the actuator crank, drive link, and drive crank to turn the lift/latch torque tube. The torque tube turns these components:
*
The vent door cam to release or close the vent door
*
The latch cranks to move the door up and down
*
The crank (not shown) that moves the lockout pushrod.
The lockout pushrod moves a crank that turns the lockout torque tube. The torque tube turns the lift lock cams.
A disc brake (not shown) that attaches to the rotor of the motor will not let the weight of the door backdrive the actuator.
The bungee spring compresses as the lift/latch torque tube begins to rotate. It supplies force to complete the torque tube rotation when its connection to the torque tube is past the center of rotation of the tube.
EFFECTIVITY BEJ ALL 52-35-00
Page 16
D633W101-BEJ Sep 05/2002
AFT SMALL CARGO DOOR SYSTEM -LIFT/LATCH POWER DRIVE UNIT, BUNGEE, AND LIFT CRANK
EFFECTIVITY BEJ ALL 52-35-00
Page 17
D633W101-BEJ Jan 05/2002
AFT SMALL CARGO DOOR SYSTEM -LIFT LOCK CAM -INTRODUCTION
Purpose
The lift lock cams hold the door in the lifted (unlatched) position.
Location
There is a cam on each end of the lockout torque tube.
Physical Description
The aft cam has an open hook shape. The forward cam has a curved oval shape. It goes around the lift pin. This makes sure that wind cannot cause the pins to come out of the cams when the door is open.
EFFECTIVITY BEJ ALL 52-35-00
Page 18
D633W101-BEJ Jan 05/2002
AFT SMALL CARGO DOOR SYSTEM -LIFT LOCK CAM -INTRODUCTION
EFFECTIVITY BEJ ALL 52-35-00
Page 19
D633W101-BEJ Jan 05/2002
AFT SMALL CARGO DOOR SYSTEM -LIFT LOCK CAM -FUNCTIONAL DESCRIPTION
Functional Description
When the door is closed, the lift links, door, and hinge link are in a parallelogram that can change shape as the door lifts.
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