Abstract: A pallet-type skid support for portable structures such as for washstands and commodes. It is made from polymeric material that is abrasion resistant and resistant to moisture and rot, in contrast to wooden pallets. It includes runners that are separably attached to the platform. The platform and runners are conveniently manufactured by the rotational molding process. Indicators of runner wear may be provided.

Abstract: A buttress to fit inside a tire between its beads, said beads being abutted by respective wheel rims. The buttress is formed by joining a plurality of arcuate segments. Each segment has an arcuate central and two edge walls. Each one of a plurality of blades is integral with all of the walls. The blades are parallel so the entire segment can be made by an injection molding process.

Abstract: A buttress to be placed between beads of a pneumatic tire which in turn are clamped against the buttress by adjoining wheel rims. The buttress is a hollow unibody construction formed of plastic material by a rotary molding procedure. The buttress is first formed flat and then bent to a circular shape with the ends pinned together, or as a pair of flat members bent and joined together. It includes a plurality of hollow posts that extend between longitudinal side rail, the side rails being abutted by the rims when installed.