for safety or operational requirements of the unit. The
case, the cylinder provides equal areas on each side of
different designs of lock cylinders vary between
the piston so that the amount of fluid and force required
manufacturers, but they are usually of the ball-lock or
to move the piston a certain distance in one direction is
finger-lock type. At times, indicating devices are also
exactly the same as the amount required to move it an
incorporated along with the lock feature of the
equal distance in the opposite direction.
cylinders.
Actuators are designed for a particular type of
BALL-LOCK ACTUATOR.--The cylinder
installation. For example, internal locking cylinders
shown in figure 11-3 is a single-action, ball-lock
are used on some bomb bay door installations, while
actuating cylinder. Its purpose is to lock the down-lock
cushioned types are used where it is necessary to slow
mechanism of the landing gear. The ball-lock feature
the extension or retraction of landing gears.
is in the lock position when the landing gear is
extended.
Mechanical-Lock Actuating Cylinder
The main parts of this cylinder are the body, end
In many installations it is necessary to lock an
caps, piston shaft and head, ball-lock plunger, locking
actuating cylinder in a specified position. This may be
ball bearings, ball bearing race, spring guide,
Figure 11-3.--Cutaway of a single-action, ball-lock actuating cylinder.
11-3
