Patent US5064023A successfully refreshed from Google Patents.
US5064023A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Flexible ladder for use on moving conveyances
Assignee: Caterpillar Global Mining Equipment LLC
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Filing: 1990-11-26
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Granted: 1991-11-12
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Expires: 2010-11-26
Abstract
Abstract A flexible ladder for use on moving conveyances which provides frontal stability but lateral flexibility, the ladder having a first, a second and a third strut member each formed of flexible material and each supported in a generally vertical plane, the strut members being parallel to each other with the second strut member between the first and third strut members. A first set of steps are secured between the first and second strut members and a second set of steps are secured between the second and third strut members the steps being vertically spaced apart from each other and the upper ends of each of the strut members being affixed to a moving conveyance, the ladder providing for ascent of an operator to the operating position on the conveyance but permitting lateral flexiblity if the ladder engages an obstruction on the surface on which the machine moves.
Inventors
- 👤 Frederick W. Loeber
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 12:52
CPC Classifications
E; E02; E02F; E02F9/00; E02F9/08; E02F9/0833; B; B60; B60R; B60R3/00; E06; E06C; E06C5/00; E06C5/02
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
281 words
A ladder for use on moving conveyances providing frontal stability but lateral flexibility, comprising: a first, a second and a third strut members each formed of flexible material and each being supported in a generally vertical plane, the strut members being generally parallel to each other with the second strut member between the first and third strut members, the spacing between the first and second strut members being at least sufficient to receive the foot of a user therebetween and the spacing between the second and third strut members being substantially equal to that between the first and second strut members, each strut member being generally flat with opposed first and second sides, with a forward edge and a rearward edge, and each having an upper end and a lower end; a first set of steps comprising at least one step, each step being generally horizontal and having opposed first and second ends, the first end of each step of the first set being secured to said first strut member and the second end of each step of the first set being secured to said second strut member, the steps being vertically spaced apart from each other; a second set of steps comprising at least two steps, each step being generally horizontal and having opposed first and second ends, the first end of each step of the second set being secured to said second strut member and the second end of each step of the second set being secured to said third strut member, the steps being vertically spaced apart from each other; and means of attachment of said upper end of each of said strut members to a moving conveyance.
Claim 2
Dependent Claim
281 words
A ladder for use on moving conveyances providing frontal stability but lateral flexibility, comprising: a first, a second and a third strut members each formed of flexible material and each being supported in a generally vertical plane, the strut members being generally parallel to each other with the second strut member between the first and third strut members, the spacing between the first and second strut members being at least sufficient to receive the foot of a user therebetween and the spacing between the second and third strut members being substantially equal to that between the first and second strut members, each strut member being generally flat with opposed first and second sides, with a forward edge and a rearward edge, and each having an upper end and a lower end; a first set of steps comprising at least one step, each step being generally horizontal and having opposed first and second ends, the first end of each step of the first set being secured to said first strut member and the second end of each step of the first set being secured to said second strut member, the steps being vertically spaced apart from each other; a second set of steps comprising at least two steps, each step being generally horizontal and having opposed first and second ends, the first end of each step of the second set being secured to said second strut member and the second end of each step of the second set being secured to said third strut member, the steps being vertically spaced apart from each other; and means of attachment of said upper end of each of said strut members to a moving conveyance.
Claim 3
Dependent Claim
26 words
A ladder according to claim 1 wherein said first set of steps are vertically displaced relative to said second set of steps in an alternating arrangement.
Claim 4
Dependent Claim
45 words
A ladder according to claim 2 wherein said first strut member is of shorter length than said second and third strut members and wherein said first strut member lower end is thereby vertically positioned above the lower ends of said second and third strut members.
Claim 5
Dependent Claim
26 words
A ladder according to claim 1 wherein said first, second and third strut members forward edges are inclined at an obtuse angle relative to the horizontal.
Claim 6
Dependent Claim
13 words
A ladder according to claim 4 wherein said angle is about 68 degrees.
Claim 7
Dependent Claim
22 words
A ladder according to claim 1 including elongated metal straps affixed to one side of at least some of said strut members.
Claim 8
Dependent Claim
24 words
A ladder according to claim 1 including elongated metal straps affixed to one side of each of said strut members adjacent said rearward edges.
Claim 9
Dependent Claim
131 words
A ladder according to claim 1 including: a first set of horizontal spacers comprising at least one spacer, each spacer having opposed ends, one end of each spacer of the first set being affixed to said first strut member and the other end being affixed to said second strut member, the spacers of the first set being vertically spaced from said first set of steps; and a second set of horizontal spacers comprising at least one spacer, each spacer having opposed ends, one end of each spacer of the second set being affixed to said second strut member and the other end of each spacer of the second set being affixed to said third strut member, the spacers of the second set being vertically spaced from said second set of steps.
Claim 10
Dependent Claim
38 words
A ladder according to claim 1 including: a toe board member for each said step, each having an upwardly inclined portion serving to limit the possibility of the foot of a user extending fully between adjacent strut members.
References Cited (Backward Citations)
US3603429A
Cited
US3887216A
Cited
US4054298A
Cited
US4054299A
Cited
DE2816971A1
Cited
US4199040A
Cited
US4333547A
Cited
US4328880A
Cited
US4316524A
Cited
US4509617A
Cited
US4535871A
Cited
US4564205A
Cited
US4627200A
Cited
US4673011A
Cited
US4845841A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-11-11 | 1995-05-13 | 1995-11-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-11-11 | 1999-05-13 | 1999-11-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-11-11 | 2003-05-13 | 2003-11-12 | $7700.00 | Window Closed / Lapsed |