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US4967879A Expired / Lapsed US ⏱️ 0.0 years remaining

Ladder

Assignee: Zarges Leichtbau GmbH
•
Filing: 1989-02-23
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Granted: 1990-11-06
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Expires: 2009-02-23
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Abstract

Abstract A ladder, especially for use in manholes, where the rungs are mounted in double-walled sidepieces via respective sleeves. Each sleeve has a body wall that, to uniformly support introduced forces, extends through both walls of a sidepiece and, especially from the outside, is arrested by connections between the rung and sleeve on the one hand and the sleeve and sidepiece on the other hand. At the same time, an outwardly directed base of the sleeve protects not only the rung but also the outer wall of the sidepiece.

Inventors

  • 👤 Ulrich Klafs
  • 👤 Carlheinz Mannhardt
  • 👤 Heinz Pecher
  • 👤 Oswald Riedl

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-24 16:03
CPC Classifications
E; E06; E06C; E06C7/00; E06C7/08; E06C7/082; E06C7/087; F; F16; F16B; F16B2/00; F16B2/20; F16B2/22; F16B7/00; F16B7/04; F16B7/044; F16B7/048; F16B9/00; F16B9/05; F16B9/056

Claims Analysis

Total Claims: 19
Claim 1
Independent Claim 150 words
In a ladder having sidepieces with wall means that are provided with holes for rungs, whereby each end portion of a rung is connected with a sidepiece via a sleeve that is disposed in a rung hole, with said sleeve having a base and, connected thereto, a sleeve body wall that is adapted to extend about said end portion of said rung, the improvement therewith wherein: said sleeve body wall extends through said wall means of said sidepiece, with a support of said rung on said sidepiece being uniformly effected in said wall means thereof via said sleeve body wall, said wall means of said sidepiece including an inner wall that faces said rung, and an outer wall that is remote from said rung; said sleeve being provided with at least one detent means, which catches against one of said walls of said sidepiece, said detent means being resiliently prestressed.
Claim 2
Dependent Claim 150 words
In a ladder having sidepieces with wall means that are provided with holes for rungs, whereby each end portion of a rung is connected with a sidepiece via a sleeve that is disposed in a rung hole, with said sleeve having a base and, connected thereto, a sleeve body wall that is adapted to extend about said end portion of said rung, the improvement therewith wherein: said sleeve body wall extends through said wall means of said sidepiece, with a support of said rung on said sidepiece being uniformly effected in said wall means thereof via said sleeve body wall, said wall means of said sidepiece including an inner wall that faces said rung, and an outer wall that is remote from said rung; said sleeve being provided with at least one detent means, which catches against one of said walls of said sidepiece, said detent means being resiliently prestressed.
Claim 3
Dependent Claim 20 words
A ladder according to claim 1, in which said detent means is directed toward said outer wall of said sidepiece.
Claim 4
Dependent Claim 29 words
A ladder according to claim 2, in which said sleeve is embodied as a single piece and is introduced into said sidepiece from an outer side of said ladder.
Claim 5
Dependent Claim 36 words
A ladder according to claim 1, in which said sleeve is provided with an abutment surface that forms a stop for that surface of said outer wall of said sidepiece that faces away from said rung.
Claim 6
Dependent Claim 33 words
A ladder according to claim 1, in which said sleeve, when inserted in said sidepiece, extends about said rung with a press fit that at most causes a resilient deformation of said rung.
Claim 7
Dependent Claim 41 words
A ladder according to claim 1, in which said rung extends into said sleeve to such an extent that said rung braces said body wall of said sleeve against said outer wall of said sidepiece from the interior of said sleeve.
Claim 8
Dependent Claim 185 words
In a ladder having sidepieces with wall means that are provided with holes for rungs, whereby each end portion of a rung is connected with a sidepiece via a sleeve that is disposed in a rung hole, with said sleeve having a base and, connected thereto, a sleeve body wall that is adapted to extend about said end portion of said rung, the improvement therewith wherein: said sleeve body wall extends through said wall means of said sidepiece, with a support of said rung on said sidepiece being uniformly effected in said wall means thereof via said sleeve body wall, said wall means of said sidepiece including an inner wall that faces said rung, and an outer wall that is remote from said rung; said sleeve being provided with at least one detent means, which catches against one of said walls of said sidepiece, said sleeve being provided, as an integral component thererof, with an arresting tongue that is resiliently prestressed in a direction toward said rung; and in which integrally formed on said arresting tongue is a projection that is directed toward said rung.
Claim 9
Dependent Claim 185 words
In a ladder having sidepieces with wall means that are provided with holes for rungs, whereby each end portion of a rung is connected with a sidepiece via a sleeve that is disposed in a rung hole, with said sleeve having a base and, connected thereto, a sleeve body wall that is adapted to extend about said end portion of said rung, the improvement therewith wherein: said sleeve body wall extends through said wall means of said sidepiece, with a support of said rung on said sidepiece being uniformly effected in said wall means thereof via said sleeve body wall, said wall means of said sidepiece including an inner wall that faces said rung, and an outer wall that is remote from said rung; said sleeve being provided with at least one detent means, which catches against one of said walls of said sidepiece, said sleeve being provided, as an integral component thererof, with an arresting tongue that is resiliently prestressed in a direction toward said rung; and in which integrally formed on said arresting tongue is a projection that is directed toward said rung.
Claim 10
Dependent Claim 38 words
A ladder according to claim 7, in which said rung, on a surface thereof that is directed toward said arresting tongue, is provided with a grooving having catching surfaces directed outwardly toward said projection of said arresting tongue.
Claim 11
Dependent Claim 17 words
A ladder according to claim 8, in which said grooving of said rung has a saw-tooth configuration.
Claim 12
Dependent Claim 178 words
In a ladder having sidepieces with wall means that are provided with holes for rungs, whereby each end portion of a rung is connected with a sidepiece via a sleeve that is disposed in a rung hole, with said sleeve having a base forming a stop for said rung and, connected thereto, a sleeve body wall that is adapted to extend about said end portion of said rung, the improvement therewith wherein: said sleeve body wall extends through said wall means of said sidepiece, with a support of said rung on said sidepiece being uniformly effected in said wall means thereof via said sleeve body wall, said wall means of said sidepiece including an inner wall that faces said rung, and an outer wall that is remote from said rung; said sleeve being provided with at least one detent means, which catches against one of said walls of said sidepiece, that end of said sleeve that faces said rung being provided with an inner cone as a first guide surface for introduction of said rung into said sleeve.
Claim 13
Dependent Claim 178 words
In a ladder having sidepieces with wall means that are provided with holes for rungs, whereby each end portion of a rung is connected with a sidepiece via a sleeve that is disposed in a rung hole, with said sleeve having a base forming a stop for said rung and, connected thereto, a sleeve body wall that is adapted to extend about said end portion of said rung, the improvement therewith wherein: said sleeve body wall extends through said wall means of said sidepiece, with a support of said rung on said sidepiece being uniformly effected in said wall means thereof via said sleeve body wall, said wall means of said sidepiece including an inner wall that faces said rung, and an outer wall that is remote from said rung; said sleeve being provided with at least one detent means, which catches against one of said walls of said sidepiece, that end of said sleeve that faces said rung being provided with an inner cone as a first guide surface for introduction of said rung into said sleeve.
Claim 14
Dependent Claim 43 words
A ladder according to claim 10, in which that end of said sleeve that faces said rung is provided with an outer cone as a second guide surface for introduction of said sleeve into said rung holes of said walls of said sidepiece.
Claim 15
Dependent Claim 17 words
A ladder according to claim 11, in which said outer cone is formed on said detent means.
Claim 16
Dependent Claim 165 words
In a ladder having sidepieces with wall means that are provided with holes for rungs, whereby each end portion of a rung is connected with a sidepiece via a sleeve that is disposed in a rung hole, with said sleeve having a base and, connected thereto, a sleeve body wall that is adapted to extend about said end portion of said rung, the improvement therewith wherein: said sleeve body wall extends through said wall means of said sidepiece, with a support of said rung on said sidepiece being uniformly effected in said wall means thereof via said sleeve body wall, said wall means of said sidepiece including an inner wall that faces said rung, and an outer wall that is remote from said rung; said sleeve being provided with at least one detent means, which catches against one of said walls of said sidepiece, said base of said sleeve forming a stop for said rung, which essentially extends to said outer wall of said sidepiece.
Claim 17
Dependent Claim 165 words
In a ladder having sidepieces with wall means that are provided with holes for rungs, whereby each end portion of a rung is connected with a sidepiece via a sleeve that is disposed in a rung hole, with said sleeve having a base and, connected thereto, a sleeve body wall that is adapted to extend about said end portion of said rung, the improvement therewith wherein: said sleeve body wall extends through said wall means of said sidepiece, with a support of said rung on said sidepiece being uniformly effected in said wall means thereof via said sleeve body wall, said wall means of said sidepiece including an inner wall that faces said rung, and an outer wall that is remote from said rung; said sleeve being provided with at least one detent means, which catches against one of said walls of said sidepiece, said base of said sleeve forming a stop for said rung, which essentially extends to said outer wall of said sidepiece.
Claim 18
Dependent Claim 179 words
In a ladder having sidepieces with wall means that are provided with holes for rungs, whereby each end portion of a rung is connected with a sidepiece via a sleeve that is disposed in a rung hole, with said sleeve having a base and, connected thereto, a sleeve body wall that is adapted to extend about said end portion of said rung, the improvement therewith wherein: said sleeve body wall extends through said wall means of said sidepiece, with a support of said rung on said sidepiece being uniformly effected in said wall means thererof via said sleeve body wall, said wall means of said sidepiece including an inner wall that faces said rung, and an outer wall that is remote from said rung; said sleeve being provided with at least one detent means, which catches against one of said walls of said sidepiece, said sleeve having an essentially cup-shaped configuration, with said base of said sleeve supporting and protecting said rung toward the outside, and at the same time extending outwardly beyond said outer wall of said sidepiece.
Claim 19
Dependent Claim 179 words
In a ladder having sidepieces with wall means that are provided with holes for rungs, whereby each end portion of a rung is connected with a sidepiece via a sleeve that is disposed in a rung hole, with said sleeve having a base and, connected thereto, a sleeve body wall that is adapted to extend about said end portion of said rung, the improvement therewith wherein: said sleeve body wall extends through said wall means of said sidepiece, with a support of said rung on said sidepiece being uniformly effected in said wall means thererof via said sleeve body wall, said wall means of said sidepiece including an inner wall that faces said rung, and an outer wall that is remote from said rung; said sleeve being provided with at least one detent means, which catches against one of said walls of said sidepiece, said sleeve having an essentially cup-shaped configuration, with said base of said sleeve supporting and protecting said rung toward the outside, and at the same time extending outwardly beyond said outer wall of said sidepiece.

References Cited (Backward Citations)

NL264096A Cited
CA829130A Cited
US2989141A Cited
FR1336343A Cited
US3844588A Cited
US3914061A Cited
US4597687A Cited
US4621937A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1993-11-05 1994-05-07 1994-11-06 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1997-11-05 1998-05-07 1998-11-06 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2001-11-05 2002-05-07 2002-11-06 $7700.00 Window Closed / Lapsed

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