Abstract: Articles and a method are disclosed useful for providing a lift insert for a cast concrete product, such as a cast concrete slab or panel. The articles include a threadless plug for temporary insertion into an insert for receiving a lifting device in a cast concrete product, an insertion tool therefor, and the insert assembly. The threadless plug is characterized by an elastomeric tubular member having closure and/or abutment means on each end and dimensioned such that, in its operative position in the lift insert, such as a coil insert, the portion of the tubular member between the ends is placed in tension to positively seal against ingress of concrete into the top of the coil or insert and between the void plug and the coil during casting.

Abstract: A plug assembly, for temporary use with a concrete product insert having a coil defining an interior threaded surface, holds the insert in position adjacent a mold wall and prevents the interior of the coil from being filled with concrete. The plug assembly includes a plug having a hollow cylindrical elastomeric body defining a cavity which is open at one end of the body and a stem in the cavity attached to the body internally and extending out of the cavity a distance sufficient to provide for use of the stem as a handle. The outer surface of the cylindrical, elastomeric body is proportioned and threaded for firm matching engagement with the threaded coil interior surface upon predetermined radial compression and axial expansion of the body from its substantially unstressed condition. A support means has a first portion for insertion into the cavity in the elastomeric body and a second portion for attachment to a mold wall.

Abstract: A plug for temporary use with a coil insert in a concrete product such as a slab or panel comprises a hollow elastomeric body having the outer surface thereof proportioned and threaded for firm matching engagement within the threaded interior surface of the coil with which it is to be used upon predetermined radial contraction and axial elongation from the unstressed condition thereof. The plug is open at one end and closed at the other end, with a stem of smaller diameter projecting from its closed end. The plug is assembled in the coil by means of a rod forced internally against its closed end, causing the plug body to elongate and contract radially sufficiently to be moved axially into place within the coil, and it is removed from the coil by using its stem as a handle for applying pulling force causing sufficient elongation and radial contraction of the plug body for withdrawal from the coil.

Abstract: A resilient plug for closing and sealing the opening formed in a concrete wall by the removal of the tie rod used to support the walls forms. The elastic plug is formed with a tapered socket and has a smooth outer surface, including a tapered leading end and a main body section having a larger diameter than the hole in the concrete and extending from the leading end. The plug is engaged in a tie rod hole by inserting a rod into the socket and pushing the plug into the tie rod hole. This causes an elongation of the plug, reducing its diameter and facilitating its insertion into the tie rod hole. However, when the force applied to the plug during insertion is removed the plug expands radially, forming a tight seal with the wall of the tie rod hole.

Abstract: The split bolt comprises plural bolt segments having threaded outer surfaces which are brought radially together to render the bolt insertable into a complementary threaded recess, and spaced radially apart to cause the bolt threads to become engaged when an elongated, generally cylindrically shaped wedge member is inserted between the segments to space them into the threaded engagement. The wedge member has plural camming surfaces along the length thereof which engage corresponding camming surfaces on the inside surfaces of the bolt segments. Further, the bolt segments are interconnected by an elastic means which surrounds the segments and keeps them in surface contact with the wedge member inserted therebetween.