Patent US4442920A successfully refreshed from Google Patents.
US4442920A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Collapsible ladder
Assignee: Steelstran Industries Inc
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Filing: 1982-09-30
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Granted: 1984-04-17
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Expires: 2002-09-30
Abstract
Abstract A collapsible ladder which includes a plurality of platforms suspended from several rope segments. The rope segments are placed in open-ended notches disposed in the platforms and are clamped thereto by a plurality of clamp means, the clamp means being divided in half, each half engaging one notch and the rope therein and being clamped by an elongated fastener to the other half of the clamp means which engages another notch and the rope therein. As a result of this configuration, the elongated platforms, if damaged, can be changed individually without necessity of removal of other than the damaged platform.
Inventors
- 👤 Peter W. Gronbeck
- 👤 Dennis Mullaney
- 👤 Kimberly M. Smith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 10:28
CPC Classifications
E; E06; E06C; E06C7/00; E06C7/08; E06C7/081; E06C1/00; E06C1/52; E06C1/56
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
309 words
A collapsible ladder comprising: a plurality of elongated platforms each having a pair of spaced apart longitudinal side edges and a pair of spaced apart transverse end edges, a first pair of adjacent notches being disposed in each of said platforms adjacent to one of said end edges, the first notch of said first pair of notches opening through one of said side edges of the associated said platform, the second notch of said first pair of notches opening through the other of said side edges of the associated said platform, a second pair of adjacent notches being disposed in each of said platforms adjacent to the other of said end edges, the first notch of said second pair of notches opening through one of said side edges of the associated said platform, the second notch of said second pair of notches opening through the other of said side edges of the associated said platform; a plurality of rope segments extending between said elongated platforms for supporting said platforms in a spaced apart use position, selected portions of selected rope segments being disposed in said first and second pairs of notches; and a plurality of clamp means, some of said clamp means for clamping said selected portions of said selected rope segments in said first pairs of notches, the balance of said clamp means for clamping selected said rope segments in said second pairs of notches, each of said clamp means being divided into two halves, a rope engaging portion of each half of each of said clamp means being dimensioned for at least a portion thereof to reside within the corresponding said notch, each of said clamp means including means for securing the halves thereof together to wedge said selected portions of said rope segments between said rope engaging portions of said clamp means and said elongated platforms.
Claim 2
Dependent Claim
309 words
A collapsible ladder comprising: a plurality of elongated platforms each having a pair of spaced apart longitudinal side edges and a pair of spaced apart transverse end edges, a first pair of adjacent notches being disposed in each of said platforms adjacent to one of said end edges, the first notch of said first pair of notches opening through one of said side edges of the associated said platform, the second notch of said first pair of notches opening through the other of said side edges of the associated said platform, a second pair of adjacent notches being disposed in each of said platforms adjacent to the other of said end edges, the first notch of said second pair of notches opening through one of said side edges of the associated said platform, the second notch of said second pair of notches opening through the other of said side edges of the associated said platform; a plurality of rope segments extending between said elongated platforms for supporting said platforms in a spaced apart use position, selected portions of selected rope segments being disposed in said first and second pairs of notches; and a plurality of clamp means, some of said clamp means for clamping said selected portions of said selected rope segments in said first pairs of notches, the balance of said clamp means for clamping selected said rope segments in said second pairs of notches, each of said clamp means being divided into two halves, a rope engaging portion of each half of each of said clamp means being dimensioned for at least a portion thereof to reside within the corresponding said notch, each of said clamp means including means for securing the halves thereof together to wedge said selected portions of said rope segments between said rope engaging portions of said clamp means and said elongated platforms.
Claim 3
Dependent Claim
82 words
A ladder in accordance with claim 1, wherein each of said halves of said clamp means are substantially U-shaped and include a bight portion and a pair of leg portions, said bight portion being dimensioned for insertion in said notches, said leg portions each having a rope receiving recess opening through the ends thereof, the inside surface of said bight portion and the inside surfaces of said rope receiving recesses forming said rope engaging portion of each of said clamp means halves.
Claim 4
Dependent Claim
46 words
A ladder in accordance with claim 2, wherein each of said rope receiving recesses forces the associated said rope portion to bend partially around the innermost closed end of the associated said notch when engaged therewith to preclude slippage of said platforms along said rope segments.
Claim 5
Dependent Claim
41 words
A ladder in accordance with claim 2, wherein said leg portions of each of said halves of said clamp means are wider than the associated said bight portions, said leg portions engaging the face surfaces of the corresponding said elongated platforms.
Claim 6
Dependent Claim
124 words
A ladder in accordance with claim 2, wherein each of said platforms have disposed therein an elongated passage located between said first and second notches of said first pair of notches and an elongated passage located between said first and second notches of said second pair of notches, said securing means comprising an elongated fastener, said bight portion of each of said clamp means halves having disposed therethrough an aperture positioned such that when said bight portions are disposed in corresponding said notches, said apertures disposed in associated said clamp halves align longitudinally with each other and with the corresponding said elongated passage, each of said elongated fasteners for insertion in a pair of selected said aligned apertures and a corresponding said elongated passage.
Claim 7
Dependent Claim
22 words
A ladder in accordance in claim 5, wherein said elongated fasteners also pass through the adjacent said portions of said rope segments.
Claim 8
Dependent Claim
19 words
A ladder in accordance with claim 5, wherein said elongated fastener comprises a threaded bolt and complementary threaded nut.
Claim 9
Dependent Claim
63 words
A ladder in accordance with claim 5, wherein said rope segments each comprise braided strands, the braided strands forming spiral recesses therebetween, said rope engaging portions of each of said clamp means halves including a ridge dimensioned to reside within the adjacent said spiral recess in said rope segment which is disposed adjacent thereto when said clamp means are assembled on said platforms.
Claim 10
Dependent Claim
238 words
A ladder in accordance with claim 1, further comprising at least one elongated spreader platform, said spreader platform having a pair of spaced apart longitudinal side edges and a pair of spaced apart transverse end edges, the distance between said end edges of said spreader platform being longer than the distance between said end edges of said elongated platforms, a first pair of adjacent spreader notches being disposed in said spreader platforms between one of said end edges thereof and the center of said spreader platform, the first notch of said first pair of spreader notches opening through one of said side edges of said spreader platform, the second notch of said first pair of spreader notches opening through the other of said side edges of said spreader platform, a second pair of adjacent spreader notches being disposed in said spreader platform between one of said end edges thereof and the center of said spreader platform, the first notch of said second pair of spreader notches opening through one of said side edges of said spreader platform, the second notch of said first pair of spreader notches opening through the other of said side edges of said spreader platform, selected portions of selected rope segments being disposed in said first and second pairs of spreader notches, selected said clamp means clamping said selected portions of said selected rope segments in said first and second pairs of spreader notches.
Claim 11
Dependent Claim
221 words
A detachable step for use in conjunction with a hanging ladder including at least one rope segment, said detachable step comprising: an elongated platform including first and second spaced apart longitudinal side edges, and a pair of spaced apart transverse end edges, said elongated platform having disposed therein at least a first pair of adjacent notches, the first notch of said first pair of notches opening through one of said side edges of said platform, the second notch of said first pair of notches opening through the other of said side edges of said platform; and clamp means for removably securing said platform to selected portions of said rope segment, said clamp means being divided into two halves, one half of said clamp means for clamping a selected portion of said rope segment within one of said pair of notches, the other half of said clamp means for clamping a selected portion of said rope segment within the other of said notches, a rope engaging portion of each half of said clamp means being dimensioned for at least a portion thereof to reside within the corresponding said notch, said clamp means including means for securing the halves thereof together to wedge said selected portions of said rope segments between said rope engaging portions of said clamp means and said elongated platform.
Claim 12
Dependent Claim
221 words
A detachable step for use in conjunction with a hanging ladder including at least one rope segment, said detachable step comprising: an elongated platform including first and second spaced apart longitudinal side edges, and a pair of spaced apart transverse end edges, said elongated platform having disposed therein at least a first pair of adjacent notches, the first notch of said first pair of notches opening through one of said side edges of said platform, the second notch of said first pair of notches opening through the other of said side edges of said platform; and clamp means for removably securing said platform to selected portions of said rope segment, said clamp means being divided into two halves, one half of said clamp means for clamping a selected portion of said rope segment within one of said pair of notches, the other half of said clamp means for clamping a selected portion of said rope segment within the other of said notches, a rope engaging portion of each half of said clamp means being dimensioned for at least a portion thereof to reside within the corresponding said notch, said clamp means including means for securing the halves thereof together to wedge said selected portions of said rope segments between said rope engaging portions of said clamp means and said elongated platform.
Claim 13
Dependent Claim
56 words
A detachable step in accordance with claim 10, wherein said rope engaging portion of said clamp means is substantially arcuate and forces said selected portion of said rope segment to bend partially around the innermost closed end of said at least one notch when engaged therewith to preclude slippage of said platform along said rope segment.
Claim 14
Dependent Claim
83 words
A detachable step in accordance with claim 10, wherein each of said halves of said clamp means are substantially U-shaped and include a bight portion and a pair of leg portions, said bight portion being dimensioned for insertion in said notches, said leg portions each having a rope receiving recess opening through the ends thereof, the inside surface of said bight portion and the inside surfaces of said rope receiving recesses forming said rope engaging portion of each of said clamp means halves.
Claim 15
Dependent Claim
47 words
A detachable step in accordance with claim 12, wherein each of said rope receiving recesses forces the associated said rope portion to bend partially around the innermost closed end of the associated said notch when engaged therewith to preclude slippage of said platform along said rope segments.
Claim 16
Dependent Claim
40 words
A detachable step in accordance with claim 12, wherein said leg portions of each of said halves of said clamp means are wider than the associated said bight portions, said leg portions engaging the face surfaces of said elongated platform.
Claim 17
Dependent Claim
171 words
A detachable step in accordance with claim 12, wherein said platform has further disposed therein a second pair of adjacent notches, the first notch of said second pair of notches opening through one of said side edges of said platform, the second notch of said second pair of notches opening through the other of said side edges of said platform, an elongated passage being located between said first and second notches of said first pair of notches and an elongated passage being located between said first and second notches of said second pair of notches, said securing means comprising an elongated fastener, said bight portion of each of said clamp means halves having disposed therethrough an aperture positioned such that when said bight portions are disposed in corresponding said notches, said apertures disposed in associated said clamp halves align longitudinally with each other and with the corresponding said elongated passage, each of said elongated fasteners for insertion in a pair of selected said aligned apertures and a corresponding said elongated passage.
Claim 18
Dependent Claim
23 words
A detachable step in accordance with claim 15, wherein said elongated fasteners also pass through the adjacent said portions of said rope segments.
Claim 19
Dependent Claim
20 words
A detachable step in accordance with claim 15, wherein said elongated fastener comprises a threaded bolt and complementary threaded nut.
Claim 20
Dependent Claim
64 words
A detachable step in accordance with claim 12, wherein said rope segments each comprise braided strands, the braided strands forming spiral recesses therebetween, said rope engaging portions of each of said clamp means halves including a ridge dimensioned to reside within the adjacent said spiral recess in said rope segment which is disposed adjacent thereto when said clamp means are assembled on said platform.
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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) | 1987-04-17 | 1987-10-17 | 1988-04-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-04-17 | 1991-10-17 | 1992-04-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-04-17 | 1995-10-17 | 1996-04-17 | $7700.00 | Window Closed / Lapsed |