US3613765A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fire door dropout
Assignee: NORTH AMERICAN W-D DOOR Inc A CORP OF OH
•
Filing: 1970-09-14
•
Granted: 1971-10-19
•
Expires: 1990-09-14
Abstract
Abstract A fusible link dropout or disconnect device for a motor-operated fire door which is advantageously located on the motor shaft and is an integral part of the chain drive by which the motor operator powers the fire door support shaft through rotation to correspondingly urge the fire door through opening and closing movements. The chain drive, consisting of the usual endless loop of chain entrained about spaced-apart sprockets, functions effectively while permitting a degree of lateral shifting movement of the dropout which is utilized as the disconnecting movement thereof in the event of a fire.
Inventors
- 👤 Bernard J Sivin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 08:51
CPC Classifications
E; E05; E05F; E05F15/00; E05F15/70; E05F15/72; E05F1/00; E05F1/02; E05Y; E05Y2201/00; E05Y2201/40; E05Y2201/404; E05Y2201/41; E05Y2201/50; E05Y2900/00; E05Y2900/10; E05Y2900/13; E05Y2900/132; E05Y2900/134; Y; Y10; Y10T; Y10T24/00; Y10T24/14; Y10T24/1412; Y10T24/1441; Y10T24/1451
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
192 words
A fire door dropout including a fire door operatively arranged on a rotatable support shaft, and an improved means drivingly connected to urge said support shaft through rotation and cause corresponding opening and closing movements of said fire door, said improved means comprising a powering motoR having a motor shaft, a cooperating pair of driving and driven members arranged on said motor shaft so as to provide said driving connection between said motor shaft and said support shaft, said driven member being selectively slidably disposed on said motor shaft for sliding movement between a first operative position drivingly engaged to said driving member and a second operative clearance position removed therefrom providing a freewheeling operation of said driven member relative to said driving member and said motor shaft, and holding means including a fusible element operatively arranged to normally hold said driven member in said first operative position thereof and to release the same for sliding movement into said second operative position thereof in response to an elevated ambient temperature which melts said fusible element, whereby said fire door descends into its closed position during said freewheeling operation of said driving member.
Claim 2
Dependent Claim
192 words
A fire door dropout including a fire door operatively arranged on a rotatable support shaft, and an improved means drivingly connected to urge said support shaft through rotation and cause corresponding opening and closing movements of said fire door, said improved means comprising a powering motoR having a motor shaft, a cooperating pair of driving and driven members arranged on said motor shaft so as to provide said driving connection between said motor shaft and said support shaft, said driven member being selectively slidably disposed on said motor shaft for sliding movement between a first operative position drivingly engaged to said driving member and a second operative clearance position removed therefrom providing a freewheeling operation of said driven member relative to said driving member and said motor shaft, and holding means including a fusible element operatively arranged to normally hold said driven member in said first operative position thereof and to release the same for sliding movement into said second operative position thereof in response to an elevated ambient temperature which melts said fusible element, whereby said fire door descends into its closed position during said freewheeling operation of said driving member.
Claim 3
Dependent Claim
59 words
A fire door dropout as defined in claim 1 wherein said holding means comprises links connected on opposite sides of said fusible element and circumferentially arranged about said motor shaft at a selected location therealong so as to prevent sliding movement of said driven member along said motor shaft past said selected location while said fusible element is intact.
Claim 4
Dependent Claim
72 words
A fire door dropout as defined in claim 2 wherein said driven member includes an angularly inclined surface adapted to have a position wedged between said circumferentially arranged holding means and said motor shaft so as to minimize inadvertent sliding movement of said driven means from said first operative position thereof and also to contribute to forcing said holding means from about said motor shaft upon the melting of said fusible element.
Claim 5
Dependent Claim
43 words
A fire door dropout as defined in claim 3 wherein said driving and driven members have cooperating teeth in facing relation to each other and said members are in meshing engagement with each other in said first operative position of said driven member.
Claim 6
Dependent Claim
37 words
A fire door dropout as defined in claim 4 wherein said driving connection between said motor shaft and said support shaft includes an endless chain which is entrained about said driven member without inhibiting sliding movement thereof.
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) | 1974-10-18 | 1975-04-19 | 1975-10-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-10-18 | 1979-04-19 | 1979-10-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-10-18 | 1983-04-19 | 1983-10-19 | $7700.00 | Window Closed / Lapsed |