US3818816A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Trapdoor for smoke eduction
Assignee: PROD ESSEMES
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Filing: 1972-08-21
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Granted: 1974-06-25
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Expires: 1992-08-21
Abstract
Abstract The trap-door comprises a wall provided with a communication opening edged by a rabbet in which is included a frame, at least lower side thereof being inclined downwards to delimit a sliding plane for a framing surrounding a panel maintained by at least one lock.
Inventors
- 👤 J Petit
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 16:18
CPC Classifications
E; E05; E05F; E05F1/00; E05F1/002; A; A62; A62C; A62C2/00; A62C2/06; A62C2/18; E04; E04F; E04F17/00; E04F17/02; E05Y; E05Y2900/00; E05Y2900/10; E05Y2900/13; E05Y2900/132
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
112 words
In a building construction including a room wall having at least one eduction passage provided with an aperture for communication between said eduction passage and rooms of said building, the wall portion defining the bottom portion of said aperture being downwardly sloped towards the room, a trap door having the same shape as that of said aperture and inserted therein and resting on said bottom portion for closing the aperture, and locking means between said wall and said trap door and retaining said door in said aperture, whereby unlocking of said locking means causes said trap door to slide down by gravity along said downwardly sloped bottom portion to open said aperture.
Claim 2
Dependent Claim
112 words
In a building construction including a room wall having at least one eduction passage provided with an aperture for communication between said eduction passage and rooms of said building, the wall portion defining the bottom portion of said aperture being downwardly sloped towards the room, a trap door having the same shape as that of said aperture and inserted therein and resting on said bottom portion for closing the aperture, and locking means between said wall and said trap door and retaining said door in said aperture, whereby unlocking of said locking means causes said trap door to slide down by gravity along said downwardly sloped bottom portion to open said aperture.
Claim 3
Dependent Claim
50 words
The arrangement according to claim 1, wherein the apertures are each delimited by a substantially rectangular metal frame having a downwardly directed bottom flange while the top flange of said frame defines with the bottom flange an upwardly directed angle, lateral flanges of said frame converging towards the eduction passage.
Claim 4
Dependent Claim
30 words
The arrangement according to claim 1, wherein the wall delimiting the aperture is separated from the trap-door by insulating blocks bearing against the trap door on the posterior side thereof.
Claim 5
Dependent Claim
35 words
The arrangement according to claim 3, wherein the insulating blocks are provided with a soft insulating joint which is supported by a stainless and heat-resisting strip surrounding it and which is supported by the blocks.
Claim 6
Dependent Claim
15 words
The arrangement according to claim 1, wherein the apertures are flanged by a deep rabbet.
Claim 7
Dependent Claim
23 words
The arrangement according to claim 1, wherein the trap-door comprises facing plates made of insulating and heat resisting material and surrounding a web.
Claim 8
Dependent Claim
17 words
The arrangement according to claim 1, wherein the locking means are constituted by at least one electro-magnet.
Claim 9
Dependent Claim
23 words
The arrangement according to claim 1, further comprising means to prevent the trap door to fall down onto the floor of the room.
Claim 10
Dependent Claim
27 words
The arrangement according to claim 8, wherein said means are constituted by a retarding device connected between the trap door and to the wall delimiting the aperture.
Claim 11
Dependent Claim
60 words
The arrangement according to claim 9, wherein said means are constituted by a stroke limiting device comprising rods placed on each side of the trap door and pivotally mounteD on spindles supported at the edge of the trap door and passing through brackets fixed on the side of the trap door and comprising damping means at the lower portion thereof.
Claim 12
Dependent Claim
37 words
The arrangement according to claim 1, wherein at least one resilient means is placed between the wall delimiting the aperture and the trap door at the base thereof, said resilient means tending to eject the trap door.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-06-24 | 1977-12-24 | 1978-06-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-24 | 1981-12-24 | 1982-06-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-24 | 1985-12-24 | 1986-06-25 | $7700.00 | Window Closed / Lapsed |