US Patent 9452647 Removable chain attachment insert

A chain attachment insert has a body with a flat underside, and provides an open loop chain attachment for receiving a chain or hook in a socket in the bed of a truck. A T-bolt portion of the chain attachment insert is received in the socket. A hole through the body extends parallel to the axis of rotation defined by the T-bolt portion, and an interference peg is vertically slidable into the hole after rotation of the chain attachment insert relative to the socket. The interference peg then rests with a portion of the interference peg in the socket to interfere with and prevent the chain attachment insert from rotating relative to the socket. A lock secures the interference peg within the hole in the body.