Lifting anchor for precast concrete structures
AssigneeMidwest Concrete & Masonry Supply, Inc.
InventorMarinus Hansort
Life of this patent
Estimating the term…
Abstract
A lifting anchor for a precast concrete structure is made from a single strand of metal bar stock. The anchor includes undulations or waves that ensure proper engagement of the anchor in a desired compressed concrete zone and also minimizes interference with the pre-stressed strands in the concrete structure. The anchor can be positioned in different orientations in the structures, depending on functional requirements of particular structures, and can be made from a single strand of bar stock of desired cross-sectional thickness and shape (e.g., round or square). Also, the undulations or waves in the legs of the anchor can extend in one or both directions from a plane defined by the anchor's legs.
Claims20
A lifting anchor configured to be embedded in a precast concrete structure, said lifting anchor comprising:
- a single strand of metal bar stock bent to include a pair of elongated legs and a central section that integrally interconnects the pair of elongated legs;
- and
- wherein a lower end section of each of the pair of elongated legs includes undulations that are configured to engage in a compressed zone of a concrete structure resulting from prestressed strands cast in the concrete structure and configured to minimize interference with the prestressed strands.
An apparatus comprising:
- a precast concrete structure including a surface-forming panel portion, a panel-reinforcing rib portion, and prestressed strands disposed within the rib portion;
- a plurality of lifting anchors positioned within the rib portion;
- wherein the plurality of lifting anchors each comprise a single strand of metal bar stock that includes a pair of parallel legs and a leg-connecting section;
- and
- wherein a lower end section of each of the pair of parallel legs includes undulations shaped to engage in a compressed zone in the rib portion proximate the prestressed strands.
A method of forming a concrete structure, said method comprising:
- providing a plurality of lifting anchors that each comprise a single strand of metal bar stock that includes a pair of parallel legs and a leg-connecting section, wherein a lower end section of the legs includes undulations bent into the single strand;
- casting concrete to form a precast concrete structure that includes a surface-forming panel portion, a panel-reinforcing rib portion, and prestressed strands that extend along a length of the rib portion;
- and
- wherein, prior to hardening of the precast concrete structure, the plurality of lifting anchors are disposed within the rib portion with the undulations positioned to engage a compressed concrete zone in the precast concrete structure and to minimize interference with prestressed strands in the concrete structure.
Dependencies are inferred from the claim text.