660-R OPERATING INSTRUCTIONS Page 6
INTRODUCTION
The 660-R is a roller brake tester designed to perform VOSA MOT tests on
Class III and Class IV vehicles.
Control can be performed using the remote handset at the vehicle so one
man operation is possible and a printer is available to produce a record of
results if fitted.
Description of system components
The roller brake tester consists essentially two parts: one above ground,
the control and display console and one below ground, the road simulation
rollers. A brief description of the various features follows:
Emergency switch
The brake tester is equipped with an emergency stop switch. Note the
location of the emergency stop before starting to use the equipment. The
emergency switch is not necessary positioned in the same place at every
installation, check the location before using the equipment.
Pit unit
The rolling road consists of two sets of free roller pairs connected by a
chain and indirectly driven by two electric motors through gearboxes. The
gearbox is joined to the roller tester frame by a force transducer. During
the motor operation when the car is braking, the resultant force is
transmitted from the rollers to the brake force transducer. The outputs of
the transducers are monitored by the internal circuits and eventually
shown on the display as brake effort.
A small third roller is fitted between each pair of main rollers. These
perform two vital functions. Firstly to monitor the presence of a wheel in
the rollers so that motors can only be energised when a vehicle is present
and secondly to measure speed of the wheel that is being braked. This
ensures that the motors are automatically switched off when the tyre
starts to slip on the roller surface.
