OPEN AND SHUT CASE
Page 40
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Drivers and operators rarely give body shutters a second thought, until one jams in the roof; that's when a relatively low-cost part of a hefty investment becomes a very expensive embarrassment. JR Industries in Cardiff has ways of avoiding the pitfalls.
Shutter doors are a relatively low-cost element of a large, expensive vehicle body, but during a
busy multi-drop operation they usually make 90 slam-bang openings every working day of the week.
If neglected they're sure to fail; sod's law says it will happen when the truck has a high-value load and the driver is running late.
"The way to prevent this happening is to avoid driver misuse and carry out periodic maintenance." says JR Industries' general sales manager, Len Dormon.
Years
For 30 years this Cardiff manufacturer has been supplying the UK's bodybuilders with Whiting dry-freight and insulated shutters and specialist Robinson aluminium shutters.
As Dormon says, the doors are the only bits of the body that are designed to move, and the fact that they don't fail more often is probably down to their design sim plicity, robust build and general accessibility for repairs.
Dry-freight shutters have plywood slats; insulated shutters use polyurethane foam-filled aluminium. Intermodal doors have alloy extrusions for extra strength.
In general, shutters are just a series of planks linked by continuous or individual hinges and fitted with rollers running in tracks. They're kept in equilibrium by coiled springs in the rear header section, and move up or down via twin external cables at a push or pull from the driver. When closed a shutter is secured to the floor by a spring-assisted hook-lock.
The Whiting design uses two outer cables to control the shutter's smooth operation; each of these is connected to the bottom panel via an articulating ferrule fitted to an anchor bracket.
Pull the cables out regularly to ensure that the cable eyes can turn on their securing pins; if they're stiff, loosen the cable anchor bracket slightly.
Check that the shutter locks securely too. If the hook or latch assembly becomes worn or damaged the door will chatter in its track; once again this will shorten the life of the cables.
Rivets
Should any hinges on a standard dry-freight door need replacing, Dorman advises the use of step bolts (never use rivets or coach bolts). Simply drive them into the wood panel in place of the rivet, screw on the nut and captive washer and tighten up.
When the bodybuilder mounts the shutter assembly into the rear frame the door is adjusted so that the upper panel fits snugly against the body header section; its top seal prevents rain or dust from entering the body thanks to the vortex effect.
is by Bryan Jarvis