Mechanical Principles. A brief description is provided here to inform the operator how some of
the mechanical parts operate. Daily cleaning of some of these parts is required to ensure satisfactory
operation under normal conditions (Refer to Chapter 3 of TM 11-5815-615-10.)
a. Carriage lock. The carriage lock handle (Figure 1) allows the carriage and end-of-message
assembly to be locked in position when the LDF is not operating and is being transported. When the
carriage and end-of-message assembly are positioned at the right-hand end of the carriage frame
assembly, the carriage lock knob can be locked down to prevent the carriage and end-of-message
assembly from moving.
b. Drum drive. The drum is a metal cylinder around which the input or output copy is wrapped.
The slot on the drum contains a spring metal strip which runs the length of the drum. The strip grips the
loading edge of the copy. Pressing the PAPER RELEASE lever (Figure 5) allows the input copy or
output copy to be inserted on, or removed from, the drum. The paper release mechanism can only be
operated when the drum is mechanically stopped in the home position. The drum stop solenoid and lock
mechanism operate to lock the drum in the home position when the LDF is powered up. The drum is
rotated by the drum drive DC torque motor at 3 or 6 rps controlled by the mode of operation; except
when the binding posts are used, the VINSON digital switch position produces 6 rps for use on
wideband telephone lines.