Abstract: A support shoe assembly (30,32) for a boom having telescoping inner and outer boom sections includes a pair of articulated wear pads (52) which are mounted at the outer end of the inner boom section in sliding engagement with the inner boom section. The wear pads (52) include rounded upper surfaces in sliding engagement with the outside lower corners of the inner boom section, and rounded lower surfaces supported in similarly contoured blocks (54) for rocking movement about a transverse axis to avoid point loading and reduce bending effects so that lighter boom sections can be utilized without reducing reach or loading capacity. The support blocks (54) are preferably mounted for adjustable lateral positioning for wear/play takeup and maintenance of proper frictional engagement between the contoured support pads (52) and the lower corners of the inner boom section.

Abstract: An apparatus for treating waste water includes a revolvable disc assembly partially submerged in a tank containing waste water. The disc assembly includes a plurality of similar lightweight nonmetallic discs, each disc comprising a plurality of similar disc sections. Adjacent discs of the disc assembly engage each other and each disc has a surface configuration that cooperates with the surface configuration of the next adjacent disc to define a plurality of concentric passages between the discs. A plurality of elongate rigid rods secure the disc through yieldable joints to a pair of circular end support members and to circular intermediate support members.