How A.C. Gilbert Designed Early Interlocking Toy Construction Blocks
A 1913 patent by A.C. Gilbert for a system of toy building blocks designed to snap together to create structures.
Original patent title: “Toy construction-blocks.”
A 1913 patent by A.C. Gilbert for a system of toy building blocks designed to snap together to create structures. Granted to MYSTO Manufacturing CO in 1913 with 3 forward citations, and it is now in the public domain.
Coverage
What does this patent actually cover?
This patent describes a mechanical system for toy construction blocks that feature specific interlocking mechanisms. The design allows individual blocks to be joined together securely to form larger, stable structures. By utilizing specific protrusions and corresponding recesses on the surfaces of the blocks, the system enables children to build models that hold their shape during play.
The gap
What does this patent NOT cover?
- Does not cover modern plastic bricks that use friction-fit studs like LEGO
- Does not cover electronic or motorized construction sets
- Does not cover non-interlocking stacking blocks like wooden cubes
These exclusions are unique to PatentBrief — derived from the actual claim language, not patent-office boilerplate.
Key facts
What made this novel
The innovation lies in the specific geometry of the connectors, which aimed to balance ease of assembly for a child with enough structural integrity to keep the model from falling apart.
The Patent Drawing
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
Early 20th-century wooden construction block sets
Mysto Manufacturing toy kits
Why it matters
The bigger picture
Alfred C. Gilbert was a major figure in the American toy industry, best known for his Erector Sets. This patent represents an early attempt to standardize how children could physically assemble toys, moving beyond simple stacking toward modular, structural engineering play.
Filed
January 20, 1913
Granted
July 8, 1913
Market context
Who's building on this
Companies in this space
Modern toy companies like LEGO and various STEM-focused educational toy startups have evolved these early modular construction concepts into highly complex, precision-engineered plastic systems.
Market impact
This patent helped establish the category of modular construction toys in the early 20th century. It set a precedent for toy companies to protect their specific connector designs, a practice that remains central to the toy industry today.
Claim 1 — Plain English
What this patent covers
This patent describes a mechanical system for toy construction blocks that feature specific interlocking mechanisms. The design allows individual blocks to be joined together securely to form larger, stable structures. By utilizing specific protrusions and corresponding recesses on the surfaces of the blocks, the system enables children to build models that hold their shape during play.
The clever bit
The innovation lies in the specific geometry of the connectors, which aimed to balance ease of assembly for a child with enough structural integrity to keep the model from falling apart.
What it does not cover
- Does not cover modern plastic bricks that use friction-fit studs like LEGO
- Does not cover electronic or motorized construction sets
- Does not cover non-interlocking stacking blocks like wooden cubes
Patent timeline
Application submitted to the patent office
Application published, typically 18 months after filing
Patent officially issued
Patent enters public domain
This patent is in the public domain
See the Freedom to Build guide — what is free to use, what is not, and how to cite this patent.
PatentBrief Score
Impact Score
Limited data
Citation count
12/40
Early citations
Claim breadth
0/20
Narrow claimsclaimsThe numbered statements at the end of a patent that legally define what the inventor owns.Read more →
Recency
0/20
Older than 20 years
Assignee scale
0/20
Independent or smaller assigneeassigneeThe entity that owns the patent — usually the inventor's employer or a company.Read more →
PatentBrief Impact Score — based on citation count, claim breadth, recency, and assignee scale. Not a legal assessment.
Heuristic Value Estimate
What this patent might be worth
$7K – $21K
Midpoint $13K · expired or expiring · industry ×2.2
Heuristic only — blends forward/backward citation counts, claim scope, time remaining, litigation history, and CPC-derived industry baseline. Real valuations need a professional appraisal.
Claim text not yet imported for this patent
Concepts involved
Citations
Patent lineage
Cite this patent
Gilbert, A. C. (1913). How A.C. Gilbert Designed Early Interlocking Toy Construction Blocks (U.S. Patent No. 1,066,809). U.S. Patent and Trademark Office. https://patentbrief.org/patent/us/1066809/erector-set-gilbert
Auto-generated from the patent record. Double-check author order and the issue date against the official USPTO document before submitting.
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Common Questions
Frequently Asked Questions
What does How A.C. Gilbert Designed Early Interlocking Toy Construction Blocks cover?
A 1913 patent by A.C. Gilbert for a system of toy building blocks designed to snap together to create structures.
Who owns patent US 1066809?
MYSTO Manufacturing CO owns this patent, granted in 1913.
When does this patent expire?
This patent has expired and is now in the public domain — anyone can use the invention freely.
What is patent US 1066809 cited by?
This patent has been cited by 3 later patents that build on its ideas.
What problem does this patent solve?
Alfred C. Gilbert was a major figure in the American toy industry, best known for his Erector Sets. This patent represents an early attempt to standardize how children could physically assemble toys, moving beyond simple stacking toward modular, structural engineering play.
What does this patent NOT cover?
Does not cover modern plastic bricks that use friction-fit studs like LEGO
Patent monitoring