The Zipper — The Fastener That Replaced a Thousand Buttons

Gideon Sundback's 1917 patent describes the modern zipper — the interlocking-tooth slide fastener that became universal in clothing, luggage, and industrial applications after a 30-year struggle to make it work reliably.

What it covers

This patent describes a separable fastener with two rows of interlocking teeth and a sliding mechanism (the pull tab and slider) that engages or separates them. Each tooth has a rounded head that fits into a socket on the opposing tooth — when the slider moves in one direction, it guides the teeth into alignment and presses them together so the heads lock into the sockets. Moving the slider the other direction splits the teeth apart. The teeth are mounted on flexible fabric tape so the fastener conforms to curved surfaces. The key advance over earlier designs was the uniform, close-spaced teeth with rounded interlocking heads — previous designs had spoon-shaped hooks that were unreliable and prone to popping open.

What it doesn't cover

• —Coil zippers (nylon coil) — modern zippers often use spiral nylon coil rather than individual metal teeth; same slider mechanism, different tooth structure
• —Waterproof zippers — sealed versions that prevent water penetration use additional gasket materials
• —Magnetic closures — a different fastening mechanism entirely
• —The invisible zipper — a variant where teeth face inward, hiding the zipper in clothing seams

The clever bit

The zipper had predecessors dating back to 1851 (Elias Howe, who also invented the sewing machine, patented a similar idea and ignored it). What Sundback solved was reliability — early slide fasteners either popped open under pressure or required precise alignment to close. His breakthrough was the 'spoon-shaped' tooth (later refined to the rounded interlocking head) and extremely precise spacing — 10 teeth per inch. The slider's V-shaped channel forced teeth into alignment as it advanced, making the mechanism self-correcting. Whitcomb Judson had commercialized earlier versions; Sundback worked at his company Universal Fastener and solved what Judson couldn't. B.F. Goodrich coined the term 'zipper' in 1923 for its rubber galoshes that used the fastener.

Why it matters

Before the zipper, clothing fastened with buttons, hooks, laces, and pins — all of which required fine motor skill and time. The zipper's one-motion open-and-close made dressing faster and allowed tighter garment fits that hooks couldn't achieve. Today over 7 billion zippers are manufactured annually. The zipper also enabled waterproof and airtight seals impossible with buttons, which is why it appears in wetsuits, drysuits, hazmat gear, and spacecraft. Sundback refined his design over decades and held more than 40 patents on zipper improvements. He died in 1954, wealthy and recognized — a rare outcome for early-20th-century inventors.

Real-world examples

• 1.B.F. Goodrich popularized the zipper on rubber boots in 1923, coining the onomatopoeic name from the 'zip' sound it makes
• 2.Military adoption in World War I — the U.S. Navy used Sundback's fasteners on flying suits and money belts — was crucial to proving reliability under demanding conditions
• 3.The fashion industry resisted zippers until the 1930s, when designer Elsa Schiaparelli put them on haute couture garments and Esquire called them 'the newest tailoring idea for men'

Glossary