# How Modern Rollerblades Became Adjustable and Interchangeable > A 1982 patent describing a skate design that allows users to swap between wheels and blades and adjust their position on the boot for better performance. - **Patent:** US 4492385 - **Original title:** Skate having an adjustable blade or wheel assembly - **Owner:** Individual - **Granted:** 1985 - **Status:** Public domain (expired) - **Times cited:** 46 - **Field:** consumer_electronics, mechanical ## What it does This patent describes a mechanical mounting system that attaches a wheel or blade assembly to the bottom of a boot. The system uses an elongate channel built into a frame, which is fixed to the boot's sole. The wheel or blade assembly slides into this channel and is held in place by a close-fitting mechanical interface, specifically using projections on the assembly that lock into recesses within the frame's side walls. A manually operable fastener then secures the assembly at a specific longitudinal position, allowing the skater to shift the wheels or blades forward or backward to suit their skating style. ## What it does NOT cover - Does not cover skates where the wheels are permanently riveted or molded directly into the boot sole. - Does not cover non-adjustable wheel frames that lack the longitudinal displacement mechanism. - Does not cover ice skates that use a traditional screw-in mounting plate without the described channel-and-projection locking system. ## The clever bit The invention uses the geometry of the channel walls—specifically the depth-to-width ratio—to create a rigid, stable connection that resists the high lateral forces of skating while remaining easily removable. ## Real-world examples 1. Early Rollerblade brand inline skates 2. Convertible ice-to-inline skate systems 3. Performance inline skates with adjustable frame positioning ## Why it matters This design was foundational to the commercial success of inline skating in the 1980s and 90s. By allowing a single boot to be customized with different wheel configurations or swapped for a blade, it helped transition inline skates from niche training tools for hockey players into a mass-market consumer product. ## Frequently asked questions ### What does How Modern Rollerblades Became Adjustable and Interchangeable cover? A 1982 patent describing a skate design that allows users to swap between wheels and blades and adjust their position on the boot for better performance. ### Who owns patent US 4492385? Individual owns this patent, granted in 1985. ### 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 4492385 cited by? This patent has been cited by 46 later patents that build on its ideas. ### What problem does this patent solve? This design was foundational to the commercial success of inline skating in the 1980s and 90s. By allowing a single boot to be customized with different wheel configurations or swapped for a blade, it helped transition inline skates from niche training tools for hockey players into a mass-market consumer product. ### What does this patent NOT cover? Does not cover skates where the wheels are permanently riveted or molded directly into the boot sole. **Full plain-English explainer:** https://patentbrief.org/patent/us/4492385/inline-skates-rollerblade-olson **Original patent:** https://patents.google.com/patent/US4492385 --- _Source: PatentBrief — https://patentbrief.org. Patent facts are from public records; the plain-English explanation is PatentBrief's._ ## Related patents Semantically similar inventions in the PatentBrief corpus: - [How James Plimpton Invented the Modern Roller Skate](https://patentbrief.org/patent/us/37305/roller-skates-plimpton) — A 19th-century invention that introduced pivoting wheels to roller skates, allowing users to steer by leaning their bodies. - [Interchangeable Blades for Folding Pocket Tools](https://patentbrief.org/patent/us/4669140/leatherman-multitool) — A 1987 patent for a folding pocket knife with split handles that can securely swap out different tools, like saw blades, using a locking pivot block and protective aluminum handles. - [How King Gillette Invented the Modern Disposable Safety Razor](https://patentbrief.org/patent/us/775134/safety-razor-gillette) — King Gillette's 1904 patent for a safety razor with a thin, replaceable, double-edged blade that changed how the world shaves. - [How Jacob Schick Invented the Modern Magazine-Loading Safety Razor](https://patentbrief.org/patent/us/1721530/schick-repeating-razor) — A 1929 patent for a safety razor that uses a replaceable blade magazine, allowing users to change blades without touching the sharp edges. - [How the String Trimmer (Weed Eater) Actually Cuts Grass](https://patentbrief.org/patent/us/3826068/weed-eater-string-trimmer) — This 1974 patent describes the mechanics of using a high-speed spinning plastic line to cut grass, replacing dangerous metal blades with flexible, non-metallic material.