Scraper with pneumatic suspension and adjustment

The DIRT WHACKER^® is a scraper that uses multi-blade modules that work independently one from the other. Its unique principle of using pneumatic suspension and control is strengthened by the use of "sandwiched" tungsten carbide blades.
Each of the modules that make up the scraper is based on a 4-greased-joint parallelogram. A rubber tube is threaded through the parallelograms to form a bladder in which air pressure can be both applied and adjusted using a foot pump. The side opposite, on which the blade is bolted, is mobile and is able to move tangentially to the belt (as a pantograph would) as a function of the air pressure in the rubber bladder and thus the wear of the blade.
Scraper, in the 100% stainless steel version, supplied from Belgium and installed on a 4000mm-wide reversible belt.
Each blade operates independently of the other blades as a function of what it receives; the angle of attack remains constant at 90° whatever its position. The scraper element is made up of a non-bevelled straight section tungsten carbide blade within a mild steel protection sandwich: the total thickness is between 6 mm and 8 mm. Its operating principle is very simple: Inflating the rubber sleeve by between 0.3 kg and 0.6 kg will push the blades perpendicularly against the belt with a force of 8 to 12 kg/cm². This will create a squeegee effect on the belt thus making for a super-performing scrape. Using this configuration means that blade WEAR is negligable given that the film of material and abrasive particles is broken, shutting down immediately any source of wear.

DIRT WHACKER^® maintenance and supervision becomes practically of secondary or even no importance, the operator having to check only the pressure gauge and to use the foot pump as needed to correct for any blade wear.

The " DIRT WHACKER^® " is the only scraper in the world to give complete satisfaction when used with reversible belts. Placed in parallel or in opposition near (+/- 200 mm) the driving drums, DIRT WHACKER^® scrapers are well suited to this difficult application without the need for long and complicated disassembly procedures. In fact when the belt direction is reversed the blades pivot automatically to the new direction. They follow a trajectory that passes through a high point that is absorbed by the elasticity of the belt. The DIRT WHACKER^® can also be used on stapled belts thanks to the flexibility of its pneumatic suspension and its "sandwiched" non-bevelled carbide blade.
The illustration shows the largest scraper, in the 100% stainless steel version, supplied from Belgium and installed on a 4000mm-wide reversible belt.

Article in INFOVRAC review, n°128, June 2003