Figure 8-8. Vertical, lever-type, geared handbrakes.
b. Geared Handbrakes. Geared handbrakes are of
three types-horizontal, vertical, and lever. All types
operate in a similar manner. The handbrake operates in
harmony with the power brake, and the design is such
Figure 8-7. Typical horizontal-type handbrakes.
that, when force is applied to the brake cylinder lever at
the brake piston connection, it permits a movement of
frame, with a spur gear installed on the shaft.
not less than 14 inches. Also, when the brake piston is
Sometimes the shaft may be bent to such an extent that
in full-release position, there is no excess slack in the
the brake will be inoperative. When a bent shaft is
handbrake chain or in other connections. The brake
noticed, the brake should be tested to see whether the
wheel and drum are arranged so that both revolve when
bend is prohibitive Also, where the chain winds around
the handbrake is applied or gradually released.
the shaft, the chain must be properly secured at the
Standard 9/16-inch hand chains or minimum 3/4-inch-
bottom to the underframe. The ratchet wheel and pawl,
diameter rods are used.
where exposed, should be inspected to see that both the
wheel and pawl are secure, that they operate properly to
hold the brake in any position, and that the brake
releases properly when the pawl is released.
a. Lubrication. When cars are on shop or repair
tracks for periodic attention to airbrakes, the geared
handbrake mechanism and connections