Chief E-Z Liner II universal

Alignment and straightening

System

The Chief E-Z Liner II system consists of all the

equipment necessary for damage analysis and repair

to current vehicle models. It uses a precision universal

gauge measuring system and special pulling and

anchoring attachments in conjunction with the main

frame platform (see Figure 14.47). The equipment

consists of a main frame platform which tilts down at

the back to form a ramp, up which a vehicle can be

driven or winched. Once the car is in position, the

platform can be raised hydraulically to a horizontal

plane and locked into place.

The platform has 200 tie-down boxes which

provide unlimited holding positions for any type of

car or light commercial vehicle. Four special anchor

clamps are supplied. These lock into tie-down boxes

to locate the vehicle. The clamps themselves rotate

through 360 degrees and have height adjustment. At

the front of the unit are three independent pivoting

towers. These between them can be swung in an arc

of 180 degrees, providing a wide range of pulling

angles. Each tower is equipped with a 5 tonne

hydraulic ram to provide the pulling power, and an

adjustable collar to enable precise pulling angles

to be achieved. Two portable hydraulic rams are

also supplied for lifting, pushing and pulling, thus

proividing the means for unlimited pulling capacity

at any point on the damaged vehicle. Power for the

pulling equipment is supplied by a heavy-duty

hydraulic pump operated from a remote control

handset.

The universal gauging system gives a fast positive

visual alignment analysis before and during repair.

Six alignment gauges feature vertical and horizontal

calibrated scales, and a variety of hanging attachments.

These self-centring gauges form a skeleton

image of the damage extended below the vehicle.

Each gauge measures width from the centre line as

well as interacting with the gauge system. Width is

compared with specifications by reading the scale

through a convenient window on the top of the

centre housing (see Figure 14.48). The attachments

are calibrated to show the actual distance from the

datum plane to the attachment point. Special colour

treatment on each side of the gauges provides easy

analysis of the datum plane; yellow stripes on one

side and orange stripes on the opposite side can be

alternated to provide contrasting colours for siting.

With all the gauges in position, the simultaneous

multipull hook-ups are made and the pulling process

begins. Throughout the pulling process the gauges

show the centre line and datum plane gradually

Figure 14.46Pulling and measuring using the

Car-O-Tronic (Car-O-Liner (UK) Ltd )

Figure 14.47Chief E-Z Liner II system showing the

gauge measuring equipment (Chief Automotive Ltd )

Major accident damage 433

becoming aligned until they read central. When the

centre line and datum are aligned and the correct

length is achieved, the vehicle structure is then in

total alignment.

The Genesis electronic

Measuring system

The Genesis electronic measuring system, developed

by Chief Automotive Ltd, integrates the precision

of laser scanning with a computerized data base for

accuracy in collision repair analysis (Figures 14.49

and 14.50).

The Genesis system begins with the vehicle

specification data base. For each vehicle specification

there are graphic displays, both overhead and

side view, of the vehicle’s underbody structure

(see Figure 14.51). In addition to showing the

extent of collision damage, the Genesis system is

designed to monitor progress throughout the

repair and verify that the vehicle structure is correctly

aligned. Throughout the repair the computer

compares vehicle specifications with the manufacturer’s

current reference point measurements.

Computer printouts verify the vehicle’s structural

condition by showing overhead and side-view

diagrams.

The Genesis system measures using the principle

of triangulation. The system’s electronic body

scanner houses two spinning hubs, each of which

emits a laser beam. These two rotating laser lights

Figure 14.48Self-centring gauge showing measurement window (Chief Automotive Ltd )

Figure 14.49The Genesis electronic measuring

system (Chief Automotive Ltd )

434Repair of Vehicle Bodies

project towards light reflective targets, which are

suspended from the vehicle’s underbody reference

points. Each laser beam strikes a reflective material

in the end of the body scanner housing, which activates

a counter when the laser light is reflected

back to the hub. The beam also strikes a target,

which has retro-reflective material on one side, and

which is attached at a control point on the underside

of the vehicle. The beam is reflected back to

its source, the laser hub, which is then reflected up

to a detector above the centre of the hub, which

again activates or turns off the counter.

The number of counts the counter has made, from

when it was turned on by the beam striking the end

of the housing to when it is turned off by the beam

striking the target, can be used to calculate the angle

of the beam to the housing. The same process

occurs with the other hub, which also determines

another angle. The body scanner housing and the

two laser beams striking the target form a triangle.

Since the spinning hubs are a known distance

apart, the counters have determined two angles of

the triangle: therefore the length of the sides of

the triangle can be mathematically determined by

trigonometry (triangulation) (Figure 14.52). This

can then be further converted mathematically into

length and width measurements for the target

locations.

Figure 14.50Genesis electronic system components (Chief Automotive Ltd )

1 Computer

2 Display monitor

3 Keyboard

4 Printer

5 Workstation

6 Body scanner

7 Scanner tray

8 Targets

9 Target attachments

10 Upper body bar

11 Lower body bar

12 Scales

Major accident damage 435

The body scanner automatically reads all reference

points simultaneously, from strategically placed

targets positioned on the vehicle underbody. These

readings are then compared with published data

and are displayed in colour on the monitor screen.

Upper body and strut tower positions are

similarly located to provide height, width and

length specifications relevant to the lower body.

Genesis first displays visual guides, showing

where to place each target. It then graphically

illustrates how existing positions compare with

vehicle specifications and provides direction and

distance information for planning the repair. The

entire system stays in place while repairs are

being made.

Setting up the equipment, hanging the targets

in position, entering the vehicle’s information, and

positioning the body scanner, take a qualified

bodyshop technician approximately ten minutes.

Calibration of the vehicle is then carried out automatically

by Genesis in a few seconds.

To check progress at any moment the computer

can provide either a visual display or a printout

verification of the vehicle’s structural condition.

This can be of great benefit for insurance companies

for quick approval of additional repairs,

and also for customers requiring verification of

repairs.

Figure 14.51Computer measuring screen (Chief Automotive Ltd )

Figure 14.52Triangulation (laser measurement)

(Chief Automotive Ltd )

436Repair of Vehicle Bodies