US3601437A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Emergency-releasable latch for hatchway door
Assignee: Individual
•
Filing: 1970-07-06
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Granted: 1971-08-24
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Expires: 1990-07-06
Abstract
Abstract An emergency-releasable latch mechanism is disclosed for use with roof or deck hatchways having a hinged door or cover heavily biased by spring or other means to full open position in order to vent quickly in emergency smoke, noxious fumes, explosion pressures and the like from a room or similar enclosed space serviced by the hatchway, yet provide for latching of the door in closed position normally to shut out the weather and prevent unauthorized entry. A particularly compact and mechanically simple lever system is provided to reduce the load reaction from the heavy opening bias forces imposed on the door so that the latch tripping control can be made highly sensitive without sacrificing positive latched retention of the door under normal conditions. Both automatic and manual tripping of the latch in emergency are provided for.
Inventors
- 👤 Robert J Lyons
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 22:02
CPC Classifications
F; F24; F24F; F24F7/00; F24F7/02; F24F11/00; F24F11/30; F24F11/32; F24F11/33; F24F11/34; Y; Y10; Y10T; Y10T292/00; Y10T292/08; Y10T292/0911; Y10T292/0945; Y10T292/0951; Y10T292/0959; Y10T292/20; Y10T292/202
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
268 words
An emergency-releasable latch mechanism for the hinged cover of a hatchway, wherein the cover is heavily biased to open position relative to an access opening serviced by said hatchway but is normally restrained in closed position by said latch mechanism, said mechanism comprising: a. a mounting bracket for supporting said mechanism adjacent an unhinged edge of the hatchway cover; b. a bent lever having a longer and a shorter arm and being pivotally secured to said bracket for swinging movement in a plane generally perpendicular to that of the access opening, the point of pivotal securement being located adjacent the free end of the shorter arm of said lever; c. a pawl pivotally secured at one of its ends to said bracket adjacent the free end of the longer arm of said bent lever, said pawl having a tooth for locking engagement with said longer lever arm and being swingable into and out of leverlocking position; d. emergency-actuated means connecting the free end of said pawl to said bracket and normally restraining said pawl in leverlocking position, said emergency-actuated means being actuatable to free said pawl for pivotal movement to release said lever; e. a latching dog having a hook portion adapted to engage a latch staple for holding said door closed, said dog being pivotally mounted on said bent lever at the intersection of its longer and shorter arms for swinging movement in a plane parallel and adjacent to the plane of movement of said lever, and spring means biasing said dog about its pivot in a direction resiliently to urge said hook portion toward stapleengaging position.
Claim 2
Dependent Claim
268 words
An emergency-releasable latch mechanism for the hinged cover of a hatchway, wherein the cover is heavily biased to open position relative to an access opening serviced by said hatchway but is normally restrained in closed position by said latch mechanism, said mechanism comprising: a. a mounting bracket for supporting said mechanism adjacent an unhinged edge of the hatchway cover; b. a bent lever having a longer and a shorter arm and being pivotally secured to said bracket for swinging movement in a plane generally perpendicular to that of the access opening, the point of pivotal securement being located adjacent the free end of the shorter arm of said lever; c. a pawl pivotally secured at one of its ends to said bracket adjacent the free end of the longer arm of said bent lever, said pawl having a tooth for locking engagement with said longer lever arm and being swingable into and out of leverlocking position; d. emergency-actuated means connecting the free end of said pawl to said bracket and normally restraining said pawl in leverlocking position, said emergency-actuated means being actuatable to free said pawl for pivotal movement to release said lever; e. a latching dog having a hook portion adapted to engage a latch staple for holding said door closed, said dog being pivotally mounted on said bent lever at the intersection of its longer and shorter arms for swinging movement in a plane parallel and adjacent to the plane of movement of said lever, and spring means biasing said dog about its pivot in a direction resiliently to urge said hook portion toward stapleengaging position.
Claim 3
Dependent Claim
48 words
A latch mechanism as defined in claim 1, wherein said mounting bracket is U-shaped, said bent lever is L-shaped and is pivotally mounted on a side leg of the U with the longer arm of said lever swingable toward and away from the base leg of the U.
Claim 4
Dependent Claim
52 words
A latch mechanism as defined in claim 2, wherein said lever is formed with a pair of spaced parallel shorter arms, each of said arms being pivotally attached to a side leg of the U-shaped bracket, and said latching dog is pivotally supported between said spaced parallel shorter arms of said lever.
Claim 5
Dependent Claim
49 words
A latch mechanism as defined in claim 3, wherein said dog has a portion extending oppositely of said hook portion, said oppositely extending portion being urged to abut against a leg of said lever by said dog biasing spring means to dispose said hook portion normally in latching position.
Claim 6
Dependent Claim
70 words
A latch mechanism as defined in claim 4, wherein the vertical drawn in the latched condition of said mechanism from the staple-engaging point on said hook portion passes close to said dog pivot on the same side thereof as said lever pivot, said dog pivot being shifted by swinging of said lever on release to unlatChed condition to cause said vertical to move overcenter in respect to said dog pivot.
Claim 7
Dependent Claim
40 words
A latch mechanism as defined in claim 1, wherein said emergency-actuatable means is a remotely controlled detent member disposed normally in position to prevent swinging of said pawl but is retractable out of the path of movement of said pawl.
Claim 8
Dependent Claim
17 words
A latch mechanism as defined in claim 1, wherein said emergency-actuatable means is a thermally fusible link.
Claim 9
Dependent Claim
32 words
A latch mechanism as defined in claim 1, wherein said pawl is mounted on said bracket for pivotal movement in a plane generally perpendicular to that of said lever and latching dog.
Claim 10
Dependent Claim
32 words
A latch mechanism as defined in claim 1, wherein said pawl is mounted on said bracket for pivotal movement in a plane generally parallel to that of said lever and latching dog.
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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) | 1974-08-23 | 1975-02-22 | 1975-08-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-08-23 | 1979-02-22 | 1979-08-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-08-23 | 1983-02-22 | 1983-08-24 | $7700.00 | Window Closed / Lapsed |