US4068568A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fire safety systems
Assignee: WEST LEIGH GROUP Ltd 51-63 ST DUNSTANS ROAD WORTHING WEST SUSSEX BN13 1AA
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Filing: 1976-03-29
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Granted: 1978-01-17
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Expires: 1996-03-29
Abstract
Abstract This invention relates to systems for clearing smoke from buildings when a fire occurs therein. Smoke detectors are provided in communal units in the building and means are provided for maintaining the pressure in accommodation units of the building above that in the communal units under normal conditions, so that there is a flow of air from the accommodation units to the communal units through the cracks in the doorways separating the accommodation units from the communal units. This flow of air ensures that, if a fire occurs in any one of the accommodation units, smoke will be carried into one of the communal units where it will be detected by one of the smoke detectors. When smoke is detected, conditions are reversed, so that the pressure in the communal units is maintained above that in the accommodation units. As a result, there will be a flow of air from the communal units to the accommodation units, once again through the cracks in the doorways. This flow of air will prevent further smoke from entering the communal units from the accommodation unit in which the fire has occurred, and will ensure that the communal units remain free of smoke to provide a means of escape for the occupants of the accommodation units.
Inventors
- 👤 Cyril Herbert Moss
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 18:23
CPC Classifications
A; A62; A62C; A62C99/00
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
89 words
A fire safety system for use in a building having a plurality of accommodation units and at least one communal unit providing means of access to said accommodation units, said system including at least one smoke detector in said communal unit and means for maintaining the pressure in said accommodation units above that in the communal unit when no smoke is detected by said smoke detector and for maintaining the pressure in said communal unit above that in the accommodation units when smoke is detected by said smoke detector.
Claim 2
Dependent Claim
89 words
A fire safety system for use in a building having a plurality of accommodation units and at least one communal unit providing means of access to said accommodation units, said system including at least one smoke detector in said communal unit and means for maintaining the pressure in said accommodation units above that in the communal unit when no smoke is detected by said smoke detector and for maintaining the pressure in said communal unit above that in the accommodation units when smoke is detected by said smoke detector.
Claim 3
Dependent Claim
36 words
A system as claimed in claim 1, wherein the pressure in the accommodation units is maintained above that in the communal unit under normal conditions by reducing the pressure in the communal unit below atmospheric pressure.
Claim 4
Dependent Claim
33 words
A system as claimed in claim 2, wherein the pressure in the accommodation units is maintained substantially at atmospheric pressure under normal conditions by permanently open ventilators in exterior walls of the building.
Claim 5
Dependent Claim
46 words
A system as claimed in claim 2, wherein there is provided in each accommodation unit a fan which, under normal conditions, draws air from the exterior of the building into the respective accommodation unit and thereby maintains the pressure in that accommodation unit above atmospheric pressure.
Claim 6
Dependent Claim
23 words
A system as claimed in claim 4, wherein said fan in each accommodation unit is an integral part of an air conditioning unit.
Claim 7
Dependent Claim
21 words
A system as claimed in claim 4, wherein, when smoke is detected, the fans in the accommodation units are switched off.
Claim 8
Dependent Claim
41 words
A system as claimed in claim 1, wherein the pressure in the communal unit is maintained above that in the accommodation units when smoke is detected by increasing the pressure in the communal unit, so that it is above atmospheric pressure.
Claim 9
Dependent Claim
52 words
A system as claimed in claim 1, wherein the communal unit has one or more external walls and wherein the pressure in the communal unit is reduced below the atmospheric pressure under normal conditions by means of a fan or fans located in the, or each, external wall of the communal unit.
Claim 10
Dependent Claim
69 words
A system as claimed in claim 1, wherein the communal unit does not have any wall in contact with the exterior of said building and wherein the pressure in the communal unit is reduced below atmospheric pressure under normal conditions by drawing air from the communal unit into at least one vertical shaft by means of a fan associated with a vent in the said at least one shaft.
Claim 11
Dependent Claim
33 words
A system as claimed in claim 9, wherein, when smoke is detected by the detector in the communal unit, the fan in said shaft is reversed and its speed of operation is increased.
Claim 12
Dependent Claim
55 words
A system as claimed in claim 1, wherein at least one horizontal duct is provided between the communal unit and an external wall of the building, a vent being associated with the said at least one duct to draw air from the communal unit into the duct and thence to the exterior of the building.
Claim 13
Dependent Claim
26 words
A system as claimed in claim 11, wherein, when smoke is detected the fan in said duct is reversed and its speed of operation is increased.
Claim 14
Dependent Claim
55 words
A system as claimed in claim 1, wherein the communal unit is provided with a plurality of self-closing fire-stop doors adapted to isolate one part of the communal unit from another part of the communal unit, said self-closing doors being normally held open by electro-magnets and being allowed to close automatically when smoke is detected.
Claim 15
Dependent Claim
33 words
A system as claimed in claim 1, wherein a smoke detector is located in the communal unit in the vicinity of each of the doors between the accommodation units and the communal unit.
References Cited (Backward Citations)
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Cited
US3916566A
Cited
US3758029A
Cited
US3826180A
Cited
US3817161A
Cited
US3829010A
Cited
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Cited
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Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-01-16 | 1981-07-18 | 1982-01-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-01-16 | 1985-07-18 | 1986-01-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-01-16 | 1989-07-18 | 1990-01-17 | $7700.00 | Window Closed / Lapsed |