Section IV. Operation

Operation

General

This section contains principles of operation and operating

instructions for the Mobilizer. When operating the Mobilizer,

the operator must be completely familiar with the equipment,

and all ground safety precautions must be strictly adhered to.

Principles of Operation

Service Brake System(Part No. 7400017-502)

When air pressure is applied from the prime mover, it enters

the system and passes through an air cleaner and a tee. The

outlets of the tee are connected to the air chambers located

on each dolly. When pressure reaches the chambers, the master

cylinders are actuated, providing hydraulic pressure in the

master cylinders and operating the brakes through the inter-

connecting lines.

When air pressure is reduced, the pressure in the air cylinders

decreases and the master cylinders return to their original

positions. The. hydraulic pressure in the system is thereby

decreased and the brakes are released.

When the Mobilizer is stationary and the brake lever assembly

is engaged, tension is applied to the two brake cables and the

rear brakes are mechanically actuated. When the handle assembly

is disengaged the tension on the brake cables is relaxed and

the brakes are released.

Service Brake System (part No. 7400050-501)

The hydraulic surge brake actuator automatically applies the Mobilizer's

hydraulic brakes in synchronization with the braking action of the towing

vehicle;

. Because the forward surge of the Mobilizer and its

its payload activates the Mobilizer brakes, the braking action is in

exact proportion to the deceleration of the towing vehicle. The Mobilizer

however, is self-contained, with no inconvenient and limiting connection

to the towing vehicle.

The telescoping towbar is in line with the master cylinder piston and

is connected to the piston by means of a slideable mounted push rod.

Internal operation of the master sylinder is similar to that of an

automotive hydraulic master cylinder, but the surge brake actuator unit

has a separate fluid accumulator chamber that absorbs impact loads and

permits backing.

A pre-load coil spring serves as a hold-off to prevent premature or

intermittent, and undesirable, brake snubs which could be caused, for

example, by uneven road survances or pitching of the trailer.