US 4,194,255 · Granted 1980-03-25
The Foam Spring That Replaced Metal Coils in Cushions
This patent describes a springy foam tube with special hollows carved into its walls that let it compress and bounce back, kind of like how a sponge works but engineered to support weight. Instead of metal springs, furniture makers could use this lightweight foam to create cushions that feel bouncy and last longer.
The plain-English version
What it protects
The claim covers a tubular foam body with a specific internal structure: hollows arranged symmetrically in the walls that get bigger as they move outward from the center, creating a spring-like compression effect. What's protected here is both the overall hollow-tube design and the precise gradient pattern of those cavities, which gives the foam its elastic recovery and load-bearing properties.
Why it matters
This patent offered furniture manufacturers an alternative to traditional metal springs for cushioning. Foam springs are lighter, cheaper to produce at scale, and don't rust or wear out the same way coils do. The innovation made modern upholstered furniture more affordable and durable, which is why you'll find similar foam-spring designs in everything from office chairs to mattresses today.
Real-world use
Every time you sit in a modern office chair or couch and feel it compress then spring back up, you're likely experiencing foam springs derived from this patented design working underneath the cushion cover.
Original USPTO abstract
Elastic springy element, characterized by the fact that it consists of a mainly tubular body, made of synthetic foam material or the like, whereby the wall of the body displays a number of hollows, in staggered symmetry the cross-sectional surface of which varies from practically zero at the inner wall of the body, to a maximum value at the outer wall, for an unloaded body.
Patent details
- Publication number
- US 4,194,255
- Filing date
- 1978-10-06
- Grant date
- 1980-03-25
- Assignee
- Willy Poppe
- Inventor(s)
- POPPE, WILLY
- CPC class
- A47C27/065
Want to file your own patent?
If you're designing a new piece of furniture or cushioning system, use our free patent scanner to see what existing designs already protect the space you're thinking about.
Free patentability scan