3olt-on suspension reduces strains
Page 10
If you've noticed an error in this article please click here to report it so we can fix it.
lE BOLT-ON air suspension Inversion, first shown in protope form at the Motor Show a lar ago by Ray Smith Demounibl es Ltd, Botolph Bridge, Aerborough, is now in producm.
Originally designed as a high tflection variable height sus:nsion to replace hydraulic iuipment on truck chassis for :mountable bodies, the Ray nith air springing arrangeent, called the Sanstress, can 3o be used as a simple conver)n on ordinary trucks and ises to give an improvement in le quality and reduced chassis
d body strains.
Its rationalised parts can be sembled in various configurains to suit front as well as rear le fitment, trailer as well as ptive chassis installations and ange of load ratings from 6 to tons.
The first production examples for drive axles, Conversion is ?rely a matter of unbolting the if spring system and bolting the Ray Smith air suspension. I welding to the axle or to the assis is entailed. The chassis eft undisturbed apart from the placement of its spring 3ckets.
the axle is bolted to a chair ting on its existing spring pad each side — the chairs being! med via spherical bonded ther bushes to two long iling arms.
rhe axle is relieved of twisting esses during roll or single e bumps by the patented ation by a short quarter ellipleaf string pinned to the iling arm.
lecause the trailing arms are g, propshaft plunge is tiny, I steer effect negligible, their angular movements relative to each other are reduced and the deflection of the axle more closely approaches that of the air springs, despite these being mounted behind the tyres. The result is an unusually large wheel movement of nearly 203mm (8in) yet with a constant height of chassis.
The springs are outrigged behind the wheels, at track width, to give good roll stiffness despite the soft ride, and avoiding the weight and complication of an anti-roll bar.
A cross-boom, flexibly jointed at the tails of the trailing arms, transfers the loads from the wide spaced air springs to the axle, Sideways location is provided by spring steel guides formed by the space frame cross bracing of the outriggers which carry the air springs.
Overall geometry, chassis stress distribution and roll behaviour are all superior to the leaf spring suspension replaced, claims Ray Smith.
For demountable body installations or where an adjustable loading height is wanted a manual valve can be included in the air circuit.