US 4,585,272 · Granted 1986-04-29
The Segmented Backrest That Mimics Your Spine's Natural Curve
Imagine a chair back made of stacked tiles that bend and fold like your actual spine. This patent covers a backrest with multiple connected pieces that adjust independently to support the curve of your back when you recline, staying flexible without flopping around like a noodle.
The plain-English version
What it protects
The claim covers a chair backrest constructed from at least three articulated segments stacked on top of each other, each segment hinged on horizontal axes so they can move independently. What's protected is the specific combination of this multi-segment design with built-in resilient resistance — springs or similar mechanisms that push back against your weight as you recline, keeping the whole structure from collapsing while still allowing it to curve naturally to match your back's arch.
Why it matters
Comfort in office and home furniture depends on how well a backrest supports the spine's natural S-curve. By breaking the backrest into independent, hinged segments rather than using a single rigid or continuously flexible panel, this design lets the chair adapt to different body shapes and reclining angles while maintaining structural integrity. This approach became influential in ergonomic seating design, allowing manufacturers to build chairs that feel custom-fitted without complex electronics or hydraulics.
Real-world use
Every time you lean back in a premium office chair or recliner and feel the backrest gently conform to your spine while still supporting you, you're likely encountering this segmented, articulated principle at work.
Original USPTO abstract
A chair has a reclinable backrest formed by a series of at least three superimposed segments articulated together about respective substantially horizontal axes to define, in the reclined position of the backrest, an arcuate configuration with a curve substantially corresponding to that of the arched back of a user. Resilient means are provided for resisting the movement of the segments towards the position corresponding to the reclined position of the backrest.
Patent details
- Publication number
- US 4,585,272
- Filing date
- 1983-10-24
- Grant date
- 1986-04-29
- Assignee
- Castelli S.P.A.
- Inventor(s)
- BALLARINI; LUCIANO
- CPC class
- A47C7/405
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