US 3,731,445 · Granted 1973-05-08
The 1973 Floor Tile Lock That Stops Tiles From Popping Out
Imagine floor tiles that lock together without glue or nails—instead, they have hidden hooks underneath that slot into a special strip. Once locked in, they stay put even if someone tries to yank them straight up. It's like a puzzle piece that only works when you slide it in from the side.
The plain-English version
What it protects
The claim covers a floor tile system where material is carved away from tile edges to create downward-pointing hooks on the underside. These hooks slide into parallel channels built into a connector strip that runs between two tiles. What's protected here is the specific geometry of the undercut projections and the matching channel design that prevents tiles from being removed by vertical pulling alone.
Why it matters
This patent addresses a real problem in flooring: keeping tiles securely joined without adhesives or fasteners that can fail over time. The mechanical interlock system provides a reusable connection—you can theoretically remove and reinstall tiles by sliding them laterally rather than prying them up. This made the design attractive for modular flooring applications where flexibility and durability mattered.
Real-world use
When you're walking across a commercial or residential floor with interlocking tiles, some of them may be held together by this undercut-and-channel system rather than traditional adhesive or grout.
Original USPTO abstract
Floor tiles are joined by cutting away material along the edges so as to leave undercut projections extending downwardly from the bottom of the tiles. Joining of tiles is effected by using a strip provided with a pair of parallel channels into which extend the projections from two different tiles. The undercut configurations prevent the tiles from being removed by a simple vertical pull.
Patent details
- Publication number
- US 3,731,445
- Filing date
- 1970-08-03
- Grant date
- 1973-05-08
- Assignee
- Freudenberg C
- Inventor(s)
- HOFFMANN R,DT, WINKLER W,DT
- CPC class
- E04F15/02
Want to file your own patent?
Curious how floor tile innovations get protected? Sketch your own flooring concept and scan it through our patent database to see what's already locked down in home improvement.
Free patentability scan