US 4,901,387 · Granted 1990-02-20
The Foam Spring Mattress Topper That Lets Each Cushion Work Alone
Imagine a mattress topper made of tiny foam springs that act like independent shock absorbers. When you lie down, each foam spring supports you on its own, but when a heavier part of your body presses down, nearby springs team up to help. It's designed to reduce pressure on sensitive spots like heels during long bed rest.
The plain-English version
What it protects
The claim covers a mattress overlay made from a rectangular base with multiple individual foam springs—each one a separate block topped with a polyhedron-shaped cushion. What's protected is the specific design where the springs are close enough to work together for heavier body weight but far enough apart to act independently for lighter pressure points. The patent also covers a medical version with two different heights of springs: taller ones in the main support area and shorter ones in a secondary section to reduce pressure on the lower extremities.
Why it matters
This patent addresses a real medical problem: prolonged bed rest causes painful pressure sores, especially on heels and lower legs. By combining independent and cooperative foam springs in one overlay, the design reduces localized pressure while maintaining support—a smarter approach than a solid foam pad that pushes uniformly everywhere. The medical variant shows the inventor understood how to adapt the core idea for healthcare settings where pressure relief is critical.
Real-world use
Hospital patients or people recovering from surgery at home who use a specialized mattress topper to prevent bedsores while resting for weeks are experiencing this invention directly.
Original USPTO abstract
A foam overlay (A,A') is disclosed which includes a rectangular base (C) and a plurality of individual and independently acting foam springs (B,B'). Each foam spring includes a base block (10,10') and a polyhedron body (14,14') atop each base block terminating in a planar support surface (12,12'). The foam springs are close enough to each other, yet separated sufficiently that they each act individually and independently. The foam springs may act together to support heavier portions of the body, but act independently in support of lighter body portions. Medical overlay pad (A') includes a main support section (32) and a secondary support section (30) of shorter foam springs D. Foam springs (B') of main section (32) support at a higher level than foam springs (D) of secondary support section (30). This allows pressure to be reduced on the lower extremities, such as the heel, during prolonged bed rest as well as on upper torso.
Patent details
- Publication number
- US 4,901,387
- Filing date
- 1988-03-21
- Grant date
- 1990-02-20
- Assignee
- Luke John K
- Inventor(s)
- LUKE; JOHN K.
- CPC class
- A47C27/146
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