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US 5,495,915 AGranted
Collapsible ladder
AssigneesCharles A. McDonnell, Fergus R. Fitzgerald
InventorsJames T. Weston, Richard Weston
Life of this patent
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Abstract
A collapsible ladder comprises telescopically collapsible sections, and latch mechanisms in each of the rungs for automatically locking the sections relative to one another when the sections are extended. The latch mechanisms are arranged to release the sections when a rung is collaped against the next lower rung.
Claims14
A collapsible ladder having two stiles formed of telescopically collapsible sections, said ladder comprising:
- a plurality of at least three adjacent rungs, each rung mounted between two individual sections of the respective stiles,
- a pair of latch mechanisms located in said at least three adjacent rungs for automatically locking the sections of the stiles relative to one another when the telescopic stile sections are fully extended,
- a release mechanism operatively associated with each pair of latch mechanisms for releasing its operatively associated pair of latch mechanisms from locking engagement with said stile sections to cause said ladder to collapse automatically in a bottom-to-top sequence, said release mechanisms actuating release of their operatively associated latch mechanisms from underneath a said rung,
- such that when a pair of latch mechanisms in a first rung is released from locking engagement with a pair of stile sections for a second rung immediately above said first rung, said second rung collapses downwardly against said first rung whereupon the release mechanism operatively associated with the latch mechanisms of said second rung engages the first rung and automatically releases the latch mechanisms of the second rung from locking engagement with the stile sections for a third rung immediately above said second rung to cause automatic collapse of said third rung against said second rung, said ladder automatically collapsing in sequence from bottom to top.
1 more element
A collapsible ladder having two stiles formed of telescopically collapsible sections, said ladder comprising:
- a plurality of at least three adjacent rungs, each rung mounted between two individual sections of the respective stiles,
- a pair of latch mechanisms located in said at least three adjacent rungs for automatically locking the sections of the stiles relative to one another when the telescopic stile sections are fully extended,
- a plurality of release mechanisms located in said adjacent rungs, each of said release mechanisms selectively actuating a respective latch mechanism for releasing the respective latch mechanism from locking engagement with said associated respective stile sections to cause said ladder to collapse automatically in a bottom-to-top sequence, said release mechanisms actuating release of their respective latch mechanisms from underneath a said rung,
- such that when a pair of latch mechanisms in a first rung is released from locking engagement with a pair of stile sections for a second rung immediately above said first rung, said second rung collapses downwardly against said first rung whereupon the release mechanism operatively associated with the latch mechanisms of said second rung automatically releases the latch mechanisms of the second rung from locking engagement with the stile sections for a third rung immediately above said second rung to cause automatic collapse of said third rung against said second rung, said ladder automatically collapsing in sequence from bottom to top,
- wherein each said release mechanism has a pair of release levers, each pivotally coupled to its said operatively associated latch mechanisms, said release levers extending downwardly from its corresponding rung toward the adjacent rung immediately therebelow, such that as the second rung collapses against the first rung, the pair of release levers extending from said second rung cause release of their operatively associated latch mechanisms upon impact against the first rung to cause the third rung to collapse against said second rung,
- wherein said pair of latch mechanisms have a pair of outwardly biased pins for lockably engaging said stile sections and said release levers have bell crank release levers pivotally attached to said pins for retracting the pins from the stiles when one rung is collapsed onto the adjacent rung immediately below it.
3 more elements
A collapsible ladder having two stiles formed of telescopically collapsible sections, said ladder comprising:
- a plurality of at least three rungs, each of said rungs being mounted between a pair of individual sections of the respective stiles,
- a latch mechanism mounted to at least three said rungs for automatically locking and unlocking the sections of the stiles that are telescopically received in the stile sections for a rung on which a said latching mechanism rung is mounted, each said latch mechanism being selectively activatable from underneath its corresponding rung to release said telescopically received stile sections for the rang above it and automatically self-collapsing mid ladder in bottom-to-top sequence as each latching mechanism engages the rung immediately below.
An automatically self-collapsing ladder comprising:
- two stiles formed of a plurality of telescopically retractable stile sections, said stiles when telescopically extended defining a top and bottom at opposite ends of said ladder;
- a plurality of rungs, each said rung being mounted between a pair of stile sections;
- a releasable latch mechanism for each rung coupled to a pair of stile sections that telescopically receive another pair of stile sections, said releasable latch mechanisms automatically locking said stile sections relative to each other to form said ladder when said stiles are fully extended, said releasable latch mechanisms being actuatable from underneath their corresponding rungs for automatically and sequentially releasing said stile sections to collapse said ladder in bottom-to-top sequence such that when the releasable latch mechanism of one rung is actuated to release the stile sections, it releases a pair of stile sections immediately above said one rung, each pair of stile sections above said one rung are automatically released, one-at-a-time, as each releasable latch mechanism engages the rung immediately below.
A collapsible ladder having two stiles formed of telescopically collapsible sections, said ladder comprising:
- a plurality of at least three adjacent rungs, each rung mounted between two individual sections of the respective stiles,
- a pair of latch mechanisms located in said at least three adjacent rungs for automatically locking the sections of the stiles relative to one another when the telescopic stile sections are fully extended,
- a plurality of release mechanisms located in said adjacent rungs, each of said release mechanisms selectively actuating a respective latch mechanism for releasing the respective latch mechanism from locking engagement with said associated respective stile sections to cause said ladder to collapse automatically in a bottom-to-top sequence, said release mechanisms actuating release of their respective latch mechanisms from underneath a said rung,
- such that when a pair of latch mechanisms in a first rung is released from locking engagement with a pair of stile sections for a second rung immediately above said first rung, said second rung collapses downwardly against said first rung whereupon the release mechanism operatively associated with the latch mechanisms of said second rung automatically releases the latch mechanisms of the second rung from locking engagement with stile sections for a third rung immediately above said second rung to cause automatic collapse of said third rung against said second rung, said ladder automatically collapsing in sequence from bottom to top,
- wherein each release mechanism has a pair of ramp-like cam members projecting upwardly from a rung top towards the adjacent rung immediately there above to cause release of the latch mechanisms in the immediately above rung from lockable engagement with a pair of stile sections as the latter rung collapses upon the former rung.
2 more elements
Dependencies are inferred from the claim text.