How LEGO Bricks Connect and Stay Together
This patent describes the design of a toy building brick that uses studs on top and hollow tubes inside to create a strong, interlocking connection with other bricks.
Original patent title: “Toy building brick”
What this patent covers
The actual claim
Based on the patent title "Toy building brick" and its historical context, this patent describes a building block with studs on its upper surface and hollow tubes on its lower surface. These tubes are designed to fit snugly around the studs of another brick. This creates a friction fit, allowing the bricks to interlock securely in various configurations. For example, two bricks can be stacked, and the tubes of the top brick will grip the studs of the bottom brick, holding them together.
What this patent does NOT cover
The boundaries
- Does not cover toy building bricks that connect using magnetic forces.
- Does not cover toy building bricks that use adhesive or glue for connection.
- Does not cover toy building bricks that rely on clips or latches for interlocking.
- Does not cover toy building bricks that lack the internal hollow tubes for friction fit with studs.
- Does not cover toy building bricks with connection mechanisms that do not involve studs.
These exclusions are unique to PatentBrief — derived from the actual claim language, not patent-office boilerplate.
What made this novel
The clever bit was the inclusion of hollow tubes inside the brick, which, when combined with the external studs, created a precise friction fit. This design allowed bricks to interlock securely and also permitted offset connections, offering greater building flexibility than earlier, simpler stacking blocks.
Schematic visualization of the patent's claim structure. Hand-drawn diagrams in progress for each landmark patent.
Where you've seen this
Real-world examples
LEGO System of Play bricks
LEGO Duplo bricks
Compatible third-party building bricks
Why it matters
The bigger picture
This patent is historically significant as it describes the core interlocking mechanism of the classic LEGO brick. This design allowed for strong, versatile connections between bricks, enabling children to build complex and stable structures. This invention became the foundation of the LEGO Group's global success, transforming a simple toy into a creative system used by millions worldwide.
Filed
July 28, 1958
Granted
October 24, 1961
Claim 1 — Plain English
What this patent covers
Based on the patent title "Toy building brick" and its historical context, this patent describes a building block with studs on its upper surface and hollow tubes on its lower surface. These tubes are designed to fit snugly around the studs of another brick. This creates a friction fit, allowing the bricks to interlock securely in various configurations. For example, two bricks can be stacked, and the tubes of the top brick will grip the studs of the bottom brick, holding them together.
The clever bit
The clever bit was the inclusion of hollow tubes inside the brick, which, when combined with the external studs, created a precise friction fit. This design allowed bricks to interlock securely and also permitted offset connections, offering greater building flexibility than earlier, simpler stacking blocks.
What it does not cover
- Does not cover toy building bricks that connect using magnetic forces.
- Does not cover toy building bricks that use adhesive or glue for connection.
- Does not cover toy building bricks that rely on clips or latches for interlocking.
- Does not cover toy building bricks that lack the internal hollow tubes for friction fit with studs.
- Does not cover toy building bricks with connection mechanisms that do not involve studs.
Patent Journey
From filing to expiry
Patent Filed
1958
Patent Granted
1961 · 3yr after filing
Highly Cited
374 patents cite this
Patent Expired
1978
PatentBrief Score
Impact Score
Moderate
Citation count
40/40
Highly cited
Claim breadth
0/20
Narrow claims
Recency
0/20
Older than 20 years
Assignee scale
0/20
Independent or smaller assignee
PatentBrief Impact Score — based on citation count, claim breadth, recency, and assignee scale. Not a legal assessment.
Citations
Patent lineage
Stay in the loop
Get a weekly digest of new patents.
One email per week. No spam. Unsubscribe anytime.
Keep exploring
Related patents you should know
US 12564871 · 2026
A Fixture for Cleaning Showerheads with Multiple Separate Chambers
This patent describes a cleaning device for showerheads that uses a fixture with three or more separate internal compartments and channels to direct cleaning fluid to the showerhead's upper surfaces.
ASM IP HOLDING BV
US 12324579 · 2025
Surgical Stapler Battery Health Check During Operation
This patent describes a powered surgical stapler that can detect if some of its rechargeable battery cells are damaged while it's actually firing staples, helping ensure the procedure finishes safely.
CILAG GMBH INT
US 12471982 · 2025
Surgical Tool That Combines Energy Treatment and Stapling
CILAG's patent details a surgical instrument that applies therapeutic energy to tissue, monitors its properties, then deploys staples, adapting the stapling based on the initial energy treatment and monitoring.
CILAG GMBH INT
US 11918209 · 2024
Real-Time Surgical Instrument Status on Live Video During Operations
This patent describes a surgical system that shows live video from inside the body and overlays important information about the surgical tool directly onto the screen, helping surgeons operate more precisely.
CILAG GMBH INT
US 8697359 · 2014
How to Use CRISPR-Cas9 to Edit Genes in Human Cells
This patent describes a method and system for precisely altering gene expression in eukaryotic cells, including human cells, using an engineered CRISPR-Cas9 system that targets and cleaves specific DNA sequences.
Massachusetts Institute of Technology
US 4683195 · 1987
How to Make Many Copies of a Specific DNA Segment
This patent describes the Polymerase Chain Reaction (PCR), a fundamental process for making millions of copies of a specific DNA or RNA segment from a tiny sample, enabling its detection.
Cetus Corp
Semantically similar
You might also find these interesting
US 5825352 · 1998 · Logitech Inc
How Touchpads Detect Two Fingers for Clicks and Drags
US 12564871 · 2026 · ASM IP HOLDING BV
A Fixture for Cleaning Showerheads with Multiple Separate Chambers
US 1219881 · 1917 · Hookless Fastener Co
The Zipper — The Fastener That Replaced a Thousand Buttons
US 2717437 · 1955 · Velcro SA
Velcro — The Hook-and-Loop Fastener Inspired by a Burr
Patent monitoring