Tilt-limit control for site tippers
Page 34
If you've noticed an error in this article please click here to report it so we can fix it.
• As semi-trailer tippers get longer, the risk of instability on rough site work is increased. With sticking loads where a steep body angle must be achieved before the material begins to flow, the centre of gravity of the vehicle as a whole can be lifted to a dangerous extent.
Neville Industries, a firm with wide experience in the field of' tipping semi-trailers, has continued its investigation into site stability which led to the development of the Ratesaver and Super Ratesaver models with their stabilizer tipping geometry.
Operators of existing tippers—rigid or artic, and of any make—can now fit a device developed by NI which senses extreme lateral tilting of a body and puts into effect, automatically, instantaneous corrective action.
A special pendulum assembly, sealed against water, is mounted 'on the body, of the tipper at a convenient point. On a semi-trailer, the greatest amount of list, to one side or the other, is monitored at the front end where the limited roll-stiffness in the fifth-wheel coupling results in a loss of overall torsional rigidity.
The pendulum actuates an electrical switch (fed through a fused circuit from the 24V vehicle system) which, in turn, controls, via a relay, a three-way arrangement of valves in the flow and return lines of the hydraulic tipping gear equipment.
Neville Industries will assess the stability characteristics of each vehicle on which the tilt-sensing device is to be installed, in order to determine the maximum angle to which the body can be permitted to tilt with safety. As an example, NI quotes 8° as being the pendulum setting on a typical semi-trailer body 24ft in length.
When the pendulum actuates the solenoid valves, the flow of fluid is immediately reversed, so lowering the body away from its potentially hazardous position.
A switch energizing the tilt-sensing device is incorporated in the pto control. On tippers with an air-controlled pto arrangement, the two switches can be readily combined.
The NI tilt control unit costs £150 for a standard installation. Insurance premium savings with the unit fitted can amount to as much as £600 per year, say the makers, Neville Industries (Mansfield) Ltd, Bradder Works, Mansfield, Notts.