Rotary-locking cube construction kit

What it does

Snap-together construction sets hold their parts by friction. Pegs press into sockets, and the fit is what keeps a model standing. As the parts wear, the fit loosens and the model falls apart, and even new parts give way under a modest pull. Some sets add a separate connector between two parts, but the connector itself is held by friction and has the same problem.

This patent covers a construction kit built from identical cubes that lock instead of gripping. Each of the six faces of a cube carries two protrusions and two recesses that register the face against the matching face of any other cube in the set, and a disk-shaped locking element that sits in an annular groove in the face and can turn. When two cubes are docked, the grooves of the two facing sides line up in one plane. A tool inserted through the center of the joint turns both disks at once, each disk moving into the groove of the opposite cube, and the two cubes are locked together by the disks rather than by friction. Turning the tool the other way releases them. A tab formed in the cube body limits how far the disk can turn so it cannot come out of the face.

What the claims cover

Claim 6 covers a single cube: six faces, each with protrusions and recesses; a locking element rotatably held in an annular groove in each face; the cube able to dock through any face to another identical cube so that the two adjoining grooves are coplanar; and the locking elements arranged to lock the two cubes together when they are turned at the same time. A cube sold as part of such a set meets this claim on its own.

Claim 1 covers the set, reciting a first cube and a second cube with those same features, dockable through any face, and lockable by simultaneously turning the locking elements of the two adjoining faces. Claim 10 covers the method of locking one such cube to another: providing the two cubes, docking them through any face so the grooves are coplanar, and locking them by turning the two locking elements together.

The dependent claims add a rotational limit that keeps the locking element from falling out of the cube (claims 2, 7 and 11), tie that limit to the shape of the faces or of the locking elements (claims 3, 8 and 12), specify that each locking element enters the groove of the other cube when turned (claims 4 and 13), and add the tool that turns both locking elements at once (claims 5, 9 and 14).

Claim strength

Three independent claims cover the cube (claim 6), the set of cubes (claim 1), and the method of locking them (claim 10). Claim 6, the shortest, recites four limitations. The examiner considered 54 U.S. patent documents during prosecution, all of them cited by the examiner and dating from 1885 through 2025, including the applicants' own pre-grant publication. The patent issued from a PCT national-stage application without a terminal disclaimer noted on its face. Term runs to about August 2043: twenty years from the November 18, 2022 international filing date, plus 283 days of patent term adjustment.

Who would want this

• Makers of building-block and construction-toy sets, where a locked joint lets larger and heavier models be built and carried.
• Educational and STEM kit companies whose sets are assembled and taken apart repeatedly and must survive classroom wear.
• Makers of modular display fixtures, storage cubes and other assembled-on-site products that need a tool-locked, tool-released joint between identical units.
• Companies producing 3D-printed or injection-molded modular systems, since the locking mechanism is formed in the cube body and the disk with no springs or separate fasteners.

Family and status

The patent issued September 22, 2026 from U.S. application 18/709,601, the national stage of PCT/RU2022/000342, published as WO 2023/091051. It claims priority to Russian application 2021133820, filed November 19, 2021. The U.S. application was published as US 2025/0001322 A1. The patent is offered for sale or for license. The owners have engaged us to find a buyer or licensee, and inquiries come to us through the form on this page.

This listing summarizes the patent as issued and reflects our reading of the public record. It is not a legal opinion on validity, enforceability, or value, and it does not create an attorney-client relationship. Underwood & Associates lists this patent on behalf of its owner; terms are set by the owner.