Patent US3828393A successfully refreshed from Google Patents.
US3828393A
Expired / Lapsed
US
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Door return and closure mechanism
Assignee: WINTHER MCDERMOTT MARION E
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Filing: 1973-10-25
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Granted: 1974-08-13
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Expires: 1993-10-25
Abstract
Abstract A spring powered door closure is disclosed consisting of two primary levers pivotally connected to the door and frame respectively. The outer free ends of the two primary levers are interconnected by a pair of crossed connecting links. The connecting links are pivotally interconnected at their midpoints, have their outer end pivotally connected to the free end of a primary lever and their inner end interconnected with the other primary lever in a manner permitting a sliding connection with the primary lever. A tension spring connected between the inner end of one connecting link and the door frame exerts a closing force on the door. As the door approaches a closed position and the force exerted by the spring decreases, the sliding connection of the connecting links to the primary levers increases the moment arm of the primary levers resulting in a substantially uniform closing force on the door throughout its entire path of travel.
Inventors
- 👤 C Pierie
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-10 02:21
CPC Classifications
E; E05; E05F; E05F1/00; E05F1/08; E05F1/10; E05F1/1041; E05F1/1066; E05Y; E05Y2900/00; E05Y2900/10; E05Y2900/13; E05Y2900/132
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
208 words
In door closure mechanism for closing a door pivoted about an axis by spring force against a frame comprising: a linkage system interconnecting the door and frame; said linkage system including a first primary lever having inner and outer ends with its inner end pivotally connected to the frame, a second primary lever having inner and outer ends with its inner end pivotally connected to the door, said first and second primary levers in the closed position of the door extending generaly parallel to one another with the outer ends therof adjacent one another, and first and second connecting links each having inner and outer ends and being pivotally connected to one another at their midpoints, said first connecting link having its outer end pivotally connected to the outer end of said first primary lever and its inner end in sliding engagement with said second primary lever, said second connecting link having its outer end pivotally connected to the outer end of said second primary lever and its inner end in sliding engagement with said first primary lever; and spring means arranged to normally urge the inner ends of said connecting links toward the inner ends of said primary levers to exert a closing force on said door.
Claim 2
Dependent Claim
208 words
In door closure mechanism for closing a door pivoted about an axis by spring force against a frame comprising: a linkage system interconnecting the door and frame; said linkage system including a first primary lever having inner and outer ends with its inner end pivotally connected to the frame, a second primary lever having inner and outer ends with its inner end pivotally connected to the door, said first and second primary levers in the closed position of the door extending generaly parallel to one another with the outer ends therof adjacent one another, and first and second connecting links each having inner and outer ends and being pivotally connected to one another at their midpoints, said first connecting link having its outer end pivotally connected to the outer end of said first primary lever and its inner end in sliding engagement with said second primary lever, said second connecting link having its outer end pivotally connected to the outer end of said second primary lever and its inner end in sliding engagement with said first primary lever; and spring means arranged to normally urge the inner ends of said connecting links toward the inner ends of said primary levers to exert a closing force on said door.
Claim 3
Dependent Claim
50 words
Apparatus in accordance with claim 1 in which said primary levers lie in a plane normal to the pivoted axis of the door and extend generally parallel to the plane of the door when the door is closed with the outer ends of said primary levers lying adjacent one another.
Claim 4
Dependent Claim
35 words
Apparatus in accordance with claim 2 in which said spring means comprises a coiled tension spring connected between the inNer end of said second connecting link and the inner end of said first primary lever.
Claim 5
Dependent Claim
30 words
Apparatus in accordance with claim 1 including adjustable snubbing means connected to said linkage system to apply a friction force to slow down the speed of closing of the door.
Claim 6
Dependent Claim
68 words
Apparatus in accordance with claim 4 in which said snubbing means includes a stub fixed to one of said connecting links and extending through the other connecting link to provide the pivotal connection between said connecting links, a friction washer carried by said stud in engagement with said other connecting link, and adjusting means on said stud to forceably engage said friction washer against said other connecting link.
Claim 7
Dependent Claim
79 words
Apparatus in accordance with claim 1 in which said first and second primary levers have outer side edge portions facing away from each other, the inner ends of said first and second connecting links each having a roller thereon with the roller of said first connecting link in engagement with the outer side edge of said second primary lever and the roller of said second connecting link in engagement with the outer side edge of said first primary lever.
Claim 8
Dependent Claim
60 words
Apparatus in accordance with claim 6 in which the outer side edges of said primary levers have an outwardly projecting cam surface thereon adapted to be engaged by said rollers as said door approaches its closed position to cause outward movement of the inner ends of said connecting links away from one another as the door approaches its closed position.
Claim 9
Dependent Claim
55 words
Apparatus in accordance with claim 7 in which said cam surfaces terminate abruptly at the point where said rollers engage the outer side edges of said first and second primary levers when the door is fully closed so that said rollers move abruptly inwardly toward one another as said door reaches its fully closed position.
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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) | 1977-08-12 | 1978-02-11 | 1978-08-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-08-12 | 1982-02-11 | 1982-08-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-08-12 | 1986-02-11 | 1986-08-13 | $7700.00 | Window Closed / Lapsed |