Patent US4336533A successfully refreshed from Google Patents.
US4336533A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fluid activated alarm device
Assignee: Individual
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Filing: 1980-12-22
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Granted: 1982-06-22
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Expires: 2000-12-22
Abstract
Abstract A liquid activatable alarm device for providing continuous monitoring of the presence or absence of a patient in a hospital bed. When the patient attempts to leave the bed, a pressure sensitive switch responds sounding an alarm warning the hospital staff.
Inventors
- 👤 Robert S. Wettach
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 00:49
CPC Classifications
G; G08; G08B; G08B21/00; G08B21/18; G08B21/22
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
127 words
A liquid activatable alarm pad for a hospital bed comprising: a flexible pressure sensitive pad having means for containment of a flowable liquid, a liquid inlet and a liquid outlet line, a check valve in communication with said outlet line, allowing free flow of said fluid out of said pad through said outlet line but restricted flow back through said outlet line to said pad, a pressure sensitive switch in fluid communication with said check valve, said switch being normally open, and closing only when pressure against said switch is reduced, said switch being connected to a circuit and a power source, and said circuit being connected to a signal means which is electrically responsive to reduction in pressure caused by removal of pressure from said pad.
Claim 2
Dependent Claim
127 words
A liquid activatable alarm pad for a hospital bed comprising: a flexible pressure sensitive pad having means for containment of a flowable liquid, a liquid inlet and a liquid outlet line, a check valve in communication with said outlet line, allowing free flow of said fluid out of said pad through said outlet line but restricted flow back through said outlet line to said pad, a pressure sensitive switch in fluid communication with said check valve, said switch being normally open, and closing only when pressure against said switch is reduced, said switch being connected to a circuit and a power source, and said circuit being connected to a signal means which is electrically responsive to reduction in pressure caused by removal of pressure from said pad.
Claim 3
Dependent Claim
14 words
The device of claim 1 wherein said check valve is a duck bill valve.
Claim 4
Dependent Claim
15 words
The device of claim 1 wherein said pressure sensitive switch is a diaphragm pressure switch.
Claim 5
Dependent Claim
19 words
The device of claim 1 wherein said pad has a series of fluid flow channels extending throughout said pad.
Claim 6
Dependent Claim
32 words
The device of claim 1 wherein said pad has a pair of side flaps, one attached to each side of said pad, for releasable securement of said pad to a hospital bed.
Claim 7
Dependent Claim
13 words
The device of claim 1 wherein said signal means is an audible alarm.
Claim 8
Dependent Claim
13 words
The device of claim 1 wherein said signal means is a visual alarm.
Claim 9
Dependent Claim
17 words
The device of claim 1 where said signal means is located at or near a nurses' station.
Claim 10
Dependent Claim
11 words
The device of claim 1 wherein said flowable liquid is water.
Claim 11
Dependent Claim
13 words
The device of claim 1 wherein said circuit includes a manual override switch.
References Cited (Backward Citations)
US3727606A
Cited
US4020482A
Cited
US4216469A
Cited
US4091370A
Cited
US4175263A
Cited
US4195287A
Cited
US4228426A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-06-21 | 1985-12-21 | 1986-06-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-06-21 | 1989-12-21 | 1990-06-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-06-21 | 1993-12-21 | 1994-06-22 | $7700.00 | Window Closed / Lapsed |