US 4,803,744 · Granted 1989-02-14
The Two-Chamber Airbed That Lets You Control Your Own Comfort
Imagine a mattress where you can dial in exactly how soft or firm it feels—because that's what this invention does. It uses two separate air chambers: one stays rigid to support your body, and the other adjusts to your personal preference. Hospitals and home users loved it because you get customized comfort without buying a whole new bed.
The plain-English version
What it protects
The claim covers an inflatable bed system with two distinct air bladders working together. What's protected here is the specific design where the lower bladder maintains constant high pressure to prevent the occupant from sinking too far, while the upper bladder can be adjusted by the sleeper to reach their ideal firmness level. The patent also covers any medical devices powered by the pressurized fluid in these chambers, plus warning systems that detect when someone leaves the bed.
Why it matters
This patent solved a real problem in hospital and home bedding: one-size-fits-all firmness doesn't work for everyone, and beds that collapse too much cause pressure sores and discomfort. By splitting the inflation system into two independent zones, the inventor created a bed that's both medically safer and personally adjustable. The assignee, Hill-Rom, became a major hospital equipment supplier, and this dual-chamber concept influenced airbed design for decades.
Real-world use
Hospital patients adjust the firmness of their beds using a bedside remote, while the lower chamber silently keeps them from bottoming out—exactly what this patent enables. Home airbed users with adjustable zones follow the same principle today.
Original USPTO abstract
This invention is concerned with an improved air bed system. In this invention, the bed occupant can control the firmness of the bed. Two inflatable bladders (12, 14) are used with a pre-set pressure differential between them. The pressure in the lower bladder is always kept high enough to prevent bottoming of a bed occupant. The pressure in the upper bladder may be adjusted by the occupant to his or her own personal comfort level. The invention may also include various medical devices which are fluid powered, thus taking advantage of the presence of the pressurized working fluid. The invention may further include a warning circuit which senses the departure of an occupant from the bed and generates a warning signal in response thereto.
Patent details
- Publication number
- US 4,803,744
- Filing date
- 1987-05-19
- Grant date
- 1989-02-14
- Assignee
- Hill-Rom Company, Inc.
- Inventor(s)
- PECK; WILLIAM H., POEHNER; MICHAEL E.
- CPC class
- A61B5/1115
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