Apparatus for roughing surfaces of concrete casted blocks

An apparatus for roughing surfaces of concrete casted blocks, said apparatus comprising a horizontally disposed surface roughing device having a plurality of impacting elements secured thereto and driven for impacting on a plurality of concrete casted blocks supported thereunder on a support table, said support table having a flat support upper surface, a plurality of holes extending through said support table, a plurality of support pins, each pin is displaceable in each of said holes and projectable above said upper surface at predetermined locations for supporting at least some of said plurality of said blocks tilted at a predetermined angle, each said pin being associated with a displaceable mechanism to axially displace said pins from a retracted position below said upper surface to a projecting block tilting position above said upper surface to tilt selected ones of casted concrete blocks disposed on said support surface, and displacement means to impart translationary displacement between said impacting elements and said support table to abrade said blocks by said impacting elements.