Rotatable blast cleaning conveying surface and apparatus

Claim 1

A blast cleaning apparatus, comprising: a blast cleaning chamber; a conveying means comprising a conveying surface having an outer periphery, said conveying surface being rotatable about a vertical axis into, through and out of the blast cleaning chamber to convey through the blast cleaning chamber a workpiece to be cleaned, said vertical axis extending through a central hole in said conveying means, said conveying surface having a plurality of openings therethrough, said openings being separated by a separating material; a blast cleaning means located below said conveying surface and oriented to direct abrasive cleaning material upwardly at said workpiece while said workpiece is inside said ablast cleaning means having an inlet for receiving said abrasive cleaning material; supply means located above said conveying surface from which said abrasive material is supplied to said blast cleaning means; and feeder through which said abrasive cleaning material is delivered under gravity from said supply means to said blast cleaning means, said feeder delivering abrasive cleaning material from said supply means to the inlet of said blast cleaning means and being inclined at an angle equal to or greater than a minimum angle of inclination required for said abrasive cleaning material to flow freely under gravity through said feeder; wherein the inlet of the blast cleaning means is positioned such that an angle of inclination of a straight line between said inlet and a point on the periphery of the conveying surface is less than said minimum angle of inclination.