Abstract: A polymeric chair having a rebar cradle and legs of a T-shaped or U-shaped cross-section diverging downwardly from the cradle. The outer surface portions of the legs define segments of a cone. Inwardly extending web portions reinforce the legs. Feet at the distal ends of the legs are disposed to the inside of the outer surface portions. A flat sand plate for the chair has radially extending slots formed therethrough which are proportioned for snug engagement with side surfaces of the feet. The slots are elongate to accommodate different sized chairs having feet spaced at varying radial dimensions. The web portions taper to optimize their reinforcing function and conserve material. In one embodiment, a ring is formed integrally with the legs intermediate the table and the distal ends of the legs. The chair is of a unitary construction and may have an integrally formed strap for extension over the cradle to secure a rebar in place.

Abstract: A lifting mechanism for a concrete structure is provided through means of a void former and anchor assembly which it cast in place to provide an accurate recess in the structure having two or more spaced divergent anchors therein. The anchors define annularly aligned apertures within the recess. A lifting shackle of an arcuate configuration complimental with that of the recess is received within the recess and carries an arcuate locking bolt extendable through the aligned apertures.

Abstract: A slotted insert having a U-shaped frame and a plastic nut box forms a concrete cone having a depth which is substantially equal to the height of the insert by utilizing tapered feet. The interior sidewalls of the U-shaped frame are formed with indentations or through holes, and the plastic nut box is formed with first projections that are in register with and held by the indentations or through holes. As a result, assembly of the nut box into the frame is accomplished by snapping the nut box into the frame. The nut box, which is also formed with a second projection that fits within the slot of the insert, is formed from a lid that is plastic welded to an open box.

Abstract: An apparatus for connecting a lifting mechanism to a load, the apparatus comprising a hollow annular body having a radial slot extending from the periphery of the body inwardly toward a central aperture. An arcuate bolt is operatively movable within the cavity of the body between a closed position wherein the bolt traverses the slot and thereby engages the load and an open position wherein the bolt is clear of the slot and, thus, disengaged from the load. At least one connector link and an actuating link lock the bolt in the closed position until the actuating link is operated on by a release mechanism.