US3924887A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pivoting link safety latch
Assignee: Individual
•
Filing: 1974-01-24
•
Granted: 1975-12-09
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Expires: 1994-01-24
Abstract
Abstract Safety latch has a latch mechanism securable to a door which cooperates with a latchplate securable to a doorframe, or vice versa, to limit the opening of the door. The safety latch has a body secured to the door, an intermediate link pivoted thereto, and an outer link pivoted to the intermediate link. A latch is movably mounted upon the outer link to selectively engage with the latchplate. When engaged, the links can fold outwardly from the base to permit the door to open, but only a limited extent.
Inventors
- 👤 Branko Markovitch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 01:55
CPC Classifications
E; E05; E05C; E05C17/00; E05C17/02; E05C17/04; E05C17/32; Y; Y10; Y10T; Y10T292/00; Y10T292/31; Y10T292/314
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
172 words
A safety latch for limiting the amount of opening of a door member with respect to a doorframe member, said safety latch comprising: a base for mounting on one of the door members adjacent the edge thereof; an intermediate link pivotally mounted on said base; an outer link pivotally mounted on said intermediate link, said base, said intermediate link, and said outer link being configured so that said outer link lies adjacent said base when said outer link is in its retracted position, and said outer link pivots outward away from said base to extend past said edge when in its extended position; a latch movably mounted on said outer link; a stationary latchplate for mounting on the other door member, said latch having a nose engageable in a latch slot in said latchplate only when said outer link is in its retracted position and said nose remaining latched in said latch slot as the door opens and said links unfold to a maximum limit position which limits the maximum door opening.
Claim 2
Dependent Claim
172 words
A safety latch for limiting the amount of opening of a door member with respect to a doorframe member, said safety latch comprising: a base for mounting on one of the door members adjacent the edge thereof; an intermediate link pivotally mounted on said base; an outer link pivotally mounted on said intermediate link, said base, said intermediate link, and said outer link being configured so that said outer link lies adjacent said base when said outer link is in its retracted position, and said outer link pivots outward away from said base to extend past said edge when in its extended position; a latch movably mounted on said outer link; a stationary latchplate for mounting on the other door member, said latch having a nose engageable in a latch slot in said latchplate only when said outer link is in its retracted position and said nose remaining latched in said latch slot as the door opens and said links unfold to a maximum limit position which limits the maximum door opening.
Claim 3
Dependent Claim
28 words
The safety latch of claim 1 wherein said outer link has a top panel and said latch is movably mounted on said outer link beneath said top panel.
Claim 4
Dependent Claim
36 words
The safety latch of claim 2 wherein a knob is positioned on the front of said outer link, said knob being connected to said latch to move said latch from its unlatched to its latched position.
Claim 5
Dependent Claim
61 words
The safety latch of claim 3 wherein said latch nose is a tee shaped nose for engagement in a tee slot in said latchplate, said latch further having a latch tongue thereon for engagement in the tee slot in said latchplate, said lAtch being pivotally mounted so that said tongue and said latch nose can be selectively engaged in said latchplate.
Claim 6
Dependent Claim
25 words
The safety latch of claim 3 wherein a lock pin interconnects said base and said outer link when said latch is in its retracted position.
Claim 7
Dependent Claim
36 words
The safety latch of claim 3 wherein said latch is a sliding latch slidably positionable from an extended position wherein its latch nose engages in an engagement slot in said latchplate to a retracted, unengaged position.
Claim 8
Dependent Claim
30 words
The safety latch of claim 6 wherein said base carries locking means thereon and said sliding latch engages said locking means for locking said outer link in the retracted position.
Claim 9
Dependent Claim
16 words
The safety latch of claim 7 wherein said base is a portion of a doorknob-mounting structure.
Claim 10
Dependent Claim
16 words
The safety latch of claim 3 wherein said base is a portion of a doorknob-mounting structure.
Claim 11
Dependent Claim
24 words
The safety latch of claim 1, also comprising spring means associated with said latch and said outer link for indexing and biasing said latch.
References Cited (Backward Citations)
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Cited
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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) | 1978-12-08 | 1979-06-09 | 1979-12-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-08 | 1983-06-09 | 1983-12-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-08 | 1987-06-09 | 1987-12-09 | $7700.00 | Window Closed / Lapsed |