Abstract: A magnetic filter removes magnetic particles from fluid communicated through the filter. The filter includes elongated, circumferentially spaced magnetic elements which capture magnetic particles entrained in the turbulent passing fluid. The magnetic elements must be cleaned periodically to remove the particles from the elements by moving a scraper plate from one end of the housing to the other. At the end of travel of the scraper plate, the particles are scraped upon non-magnetic end portions (which may contain residual magnetism) of the magnetic elements, from which they are flushed by fluid communicated through the inlet port out through other ports provided on the housing.

Abstract: A vibrator device for use in a concrete block maker in which the mold box and the underlying pallet of the device reciprocate in opposite directions relative to each other, providing compaction of the concrete mix within the mold box as supported upon the pallet.