US 6,059,368 · Granted 2000-05-09
How Herman Miller Patented a Stretchy Seat That Won't Sag
Herman Miller figured out how to build office chair seats using a pre-stretched elastic membrane attached to a frame, so they spring back instead of sagging over time. It's like replacing traditional foam padding with a sheet of flexible material that stays taut no matter how many people sit on it.
The plain-English version
What it protects
The claim covers a support assembly for chairs made from a frame with a channel, a pre-stretched elastic membrane material, and a carrier member that holds the membrane in place inside the channel. What's protected here is the specific method of stretching the elastic material before installation and the way it's secured to keep that tension. Anyone manufacturing a chair seat using this exact construction method—pre-stretching an elastic membrane and locking it into a frame channel via a carrier—would be infringing on these claims.
Why it matters
This patent represents Herman Miller's innovation in ergonomic seating design during the 1990s, when office chairs were becoming a major market segment. By replacing traditional foam and springs with a pre-tensioned elastic system, the patent protects a manufacturing method that improves durability and comfort. The approach allows chairs to maintain their shape longer under repeated use, which matters in high-volume commercial furniture where chairs endure constant daily sitting.
Real-world use
When you sit in a modern office chair that feels supportive but slightly bouncy—where the seat surface has tension rather than feeling like dense foam—you're likely experiencing a design descended from this patented membrane-and-frame system.
Original USPTO abstract
A support assembly for supporting the body of a user in a chair including a frame member having a channel. A prestretched membrane comprising an elastic material is attached to a carrier member, which is inserted in the channel. A method is also provided for manufacturing a chair including a frame member, a membrane and a carrier member.
Patent details
- Publication number
- US 6,059,368
- Filing date
- 1995-06-07
- Grant date
- 2000-05-09
- Assignee
- Herman Miller, Inc.
- Inventor(s)
- STUMPF; WILLIAM E., SCHOENFELDER; RODNEY C., CHADWICK; DONALD, KELLER; CAROLYN, COFFIELD; TIMOTHY P., SAYERS; RANDY J., BRUNER; JEFFREY W., CAMMENGA; ERIC
- CPC class
- A47C7/02
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