US 5,205,004 · Granted 1993-04-27
The Hospital Bed That Stays Level No Matter How You Tilt It
Imagine a bed that can tilt up and down on both ends independently, but if one side drifts out of position, a sensor automatically fixes it. Two electric motors work together to keep the bed exactly where you want it, even when you're adjusting it for comfort or medical reasons.
The plain-English version
What it protects
The claim covers a bed frame controlled by two separate actuators that can raise, lower, and tilt the frame, combined with a level sensor that monitors whether the frame is staying in its intended tilted position. What's protected here is the specific system where the sensor feeds information back to the actuators so they automatically correct any drift from the desired angle—this feedback loop is the key innovation.
Why it matters
This kind of adjustable bed frame became essential in hospitals and care facilities where patients need precise positioning for medical reasons, comfort, and pressure relief. By automating the leveling process with a sensor, the patent eliminated the need for manual adjustment or trial-and-error, making the bed safer and more reliable for both patients and caregivers.
Real-world use
You'd encounter this technology in modern hospital beds, adjustable mattress systems, and premium recliners that automatically maintain their angle without sagging or drifting out of position.
Original USPTO abstract
A vertically adjustable and tiltable bed frame has two actuators which may be used simultaneously or independently to tilt the frame and which also may be used to raise and lower the frame. A level sensor is connected to the actuators so that if the tilt varies from the adjusted and desired position, one or other actuator is adjusted to restore the desired tilted position.
Patent details
- Publication number
- US 5,205,004
- Filing date
- 1991-10-30
- Grant date
- 1993-04-27
- Assignee
- J. Nesbit Evans & Co. Ltd.
- Inventor(s)
- HAYES; STEPHEN, JONES; ROBERT H.
- CPC class
- A61G7/015
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