The coupler may be unlocked from either the top or the bottom depending upon how the rotary lock lifter
and its actuating parts are assembled. The coupler is designed so that these parts can be changed for either top
or bottom operation. Either operation is performed safely from beside the car by raising the uncoupling lever
that is connected to the rotary lock lifter.
Figure 5.5. Working Parts of E Coupler.
The main working parts of the coupler are as follows: The body is the main section that includes the horn,
guard arm, shank, butt, and head that houses the coupler's operating parts. The knuckle is the rotating hook,
hinged on the knuckle pin, that connects with the knuckle of another coupler. A knuckle lock drops into place
when the knuckle locks and prevents uncoupling. The lifter, when moved by the uncoupling lever, lifts the
knuckle lock and frees the knuckle for throwing. The knuckle thrower throws the knuckle open as the
uncoupling lever continues to be raised. The toggle works with the lifter to lift the knuckle lock on bottom-
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