US5072973A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Door hold open device
Assignee: Motus Inc
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Filing: 1989-10-04
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Granted: 1991-12-17
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Expires: 2009-10-04
Abstract
Abstract A door hold open device for use with fire doors connected to a door closer unit. The hold open device has a latching means that automatically unlatches if the power supply drops below a predetermined threshold or a person attempts to disconnect the power supply. The device includes an electrical actuating means for unlatching the held open door. The actuating means allows a door to be latched open without constant current being supplied to the actuating means, so battery power is possible. The invention may be used with any door closer unit, does not require special wiring, and may include a self-contained power supply and an integral smoke detector.
Inventors
- 👤 Robert C. Gudgel
- 👤 William Baker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 20:23
CPC Classifications
E; E05; E05C; E05C17/00; E05C17/02; E05C17/04; E05C17/12; E05C17/24; E05C17/28; E05B; E05B47/00; E05B47/0001; E05B2047/0014; E05B2047/0018; E05B2047/0023; E05B47/0012; Y; Y10; Y10T; Y10T292/00; Y10T292/08; Y10T292/0801; Y10T292/0848; Y10T292/0849; Y10T292/0861; Y10T292/0908; Y10T292/1043; Y10T292/1075; Y10T292/1082; Y10T292/28; Y10T292/305
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
86 words
A releasable door hold open device, comprising: a latching means for latching a door in an open position without continuous application of energy, electrical power supply receiving means, and power sensing means operatively connected to said power supply receiving means and said latching means to prevent the latching means from latching a door in an open position when the power from the power supply receiving means falls below a predetermined threshold, said threshold being high enough that the power is sufficient to unlatch said latching means.
Claim 2
Dependent Claim
86 words
A releasable door hold open device, comprising: a latching means for latching a door in an open position without continuous application of energy, electrical power supply receiving means, and power sensing means operatively connected to said power supply receiving means and said latching means to prevent the latching means from latching a door in an open position when the power from the power supply receiving means falls below a predetermined threshold, said threshold being high enough that the power is sufficient to unlatch said latching means.
Claim 3
Dependent Claim
26 words
The device of claim 1 further comprising smoke detector means operatively connected to said latching means to unlatch said latching means upon the detection of smoke.
Claim 4
Dependent Claim
20 words
The device of claim 2 wherein said smoke detector means and said power sensing means comprise a single integrated circuit.
Claim 5
Dependent Claim
54 words
The device of claim 1 wherein, said latching means comprises: at least one pivotable latch arm, at least one latch arm receiving means, cam means operatively engagable with said latch arm to thereby cause latching and unlatching of the latch arm with the latch arm receiving means, and means for reciprocating said cam means.
Claim 6
Dependent Claim
48 words
The device of claim 1 wherein said latching means comprises: a motor having a threaded rotatable shaft extending therefrom, a reciprocating member having threads engaging the threads of said shaft, such that said reciprocating member is moved toward or away from said motor upon rotation of the shaft.
Claim 7
Dependent Claim
24 words
The device of claim 5 wherein, the threads of said shaft are outer threads, and the threads of said reciprocating member are internal threads.
Claim 8
Dependent Claim
25 words
The device of claim 5 further comprising: means for stopping the rotation of said shaft upon movement of said reciprocating member by a predetermined amount.
Claim 9
Dependent Claim
26 words
The device of claim 7 wherein said stopping means comprises a magnet and a pair of switches adjacent to the path of travel of said magnet.
Claim 10
Dependent Claim
17 words
The releasable door hold-open device of claim 1, wherein the power sensing means comprises voltage sensing means.
Claim 11
Dependent Claim
81 words
A releasable door hold-open device, comprising: an actuable latching means for latching a door in an open position, electrical power supply receiving means, and power sensing means operatively connected to said power supply receiving means and said latching means to prevent the latching means from latching a door in an open position when the power from the power supply receiving means is below a predetermined threshold, said theshold being high enough that the power is sufficient to actuate said latching means.
Claim 12
Dependent Claim
81 words
A releasable door hold-open device, comprising: an actuable latching means for latching a door in an open position, electrical power supply receiving means, and power sensing means operatively connected to said power supply receiving means and said latching means to prevent the latching means from latching a door in an open position when the power from the power supply receiving means is below a predetermined threshold, said theshold being high enough that the power is sufficient to actuate said latching means.
Claim 13
Dependent Claim
43 words
The releasable door hold-open device of claim 10, wherein the power sensing means is operatively connected to the latching means to unlatch a door held in an open position when the power from the power supply receiving means falls below the predetermined threshold.
Claim 14
Dependent Claim
27 words
The releasable door hold-open device of claim 10, wherein the latching means is capable of latching a door in an open position without continuous application of power.
Claim 15
Dependent Claim
26 words
The device of claim 10 further comprising smoke detector means operatively connected to said latching means to unlatch said latching means upon the detection of smoke.
Claim 16
Dependent Claim
20 words
The device of claim 13 wherein said smoke detector means and said power sensing means comprise a single integrated circuit.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-12-16 | 1995-06-17 | 1995-12-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-12-16 | 1999-06-17 | 1999-12-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-12-16 | 2003-06-17 | 2003-12-17 | $7700.00 | Window Closed / Lapsed |