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Publication numberUS3722622 A
Publication typeGrant
Publication dateMar 27, 1973
Filing dateMar 18, 1971
Priority dateMar 18, 1971
Publication numberUS 3722622 A, US 3722622A, US-A-3722622, US3722622 A, US3722622A
InventorsLauring E
Original AssigneeLauring E
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Folding and collapsible ladders
US 3722622 A
Images(2)
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Description  (OCR text may contain errors)

United States Patent Lauring Mar. 27, 1973 {54] FOLDING AND COLLAPSIBLE 258,186 5/1882 Winters ..182/159 LADDERS 2,875,935 3/1959 Bultermore ..182/160 [76] lnvemor' x i ggga tai i g- 2 251 Primary ExaminerReinald0 P. Machado Fans, Minn 56649 1 AttorneyH. F. Woodward [22] Filed: Mar. 18, 1971 57 TR I 1 pp 1251689 A folding and collapsible ladder wherein the rungs are pivotally attached to the side rails and adjacent rungs 521 11.5. c1 ..182/159, 182/178 are attached to the Side rails in different Planes, [51] 0 adjacent rungs are offset. To collapse or fold the {58] Field of Search ..182/160, l59,95,96 ladder imo a narrow but Slightly longer mass, the rungs fold down like a closing parallelogram until the [56] References Cited rungs are substantially, parallel to the side rails. Rigidity of the ladder is provided by one or more braces UNITED STATES PATENTS pivotally attached at one end to one side rails and the 453,929 6/1891 Heister 182 160 pp end Of the braces Provided with fastening 3,517,770 6/1970 Loix ..l82/96 means to removable secure the braces to the other 1,887,301 11/1932 Gordon ..182/159 Side rail.

355,574 1/1887 Tilley 1 ..182/178 2,962,] 13 11/1960 Heimlicher 182/160 3 Claims, 10 Drawing Figures FOLDING AND COLLAPSIBLE LADDERS This invention relates to a folding ladder of the type of having a pair of side rails, collapsibly secured together and in which the side rails pivotally supports a series of spaced-apart rungs adapted to be secured in an operative position.

It is an object of the present invention to make a collapsible ladder construction in which the adjacent rungs are in different planes, i.e., offset from each other, and means being provided for locking or bracing the rungs in a parallel spaced-apart position, and which can be easily disengaged when desirable to fold or co]- lapse the ladder by closing the rails upon one another.

These and other objects and novel features will be more fully appreciated from the following description of preferred embodiments of the invention selected for purposes of illustrations and shown in the accompanying drawings in which:

FIG. 1 is a front elevational view of the novel folding or collapsible ladder:

FIG. 2 is a fragmentary view of the ladder fully col- 7 lapsed condition:

FIG. 3 is an end view showing brackets for pivotally attaching ladder rungs to the side rails:

FIG. 4 is a view of the ladder, with parts broken away, showing use of opposed channel bars for the side rails:

FIG. 5 is a view similar to FIG. 4 in which the side rails are channel bars with middle web or two channel bars secured together for side rails:

FIG. 6 is a view of the folding ladder, with parts broken away, showing solid material as side rails:

FIG. 7 is an end view of solid side rails showing two rows of rungs in different plan or offset each other:

FIG. 8 is a side view of an extension to be used with the folding ladder:

FIG. 9 is a front view, with parts broken away, showing folding ladder with folding extension: and

FIG. 10 is a side view showing the folding extension used with folding ladder to provide a self supporting ladder.

In the structures shown in the drawings numerals l0 and 12 denote side rails of wood, magnesium, aluminum, or any suitable material. The side rails 10 and 12 may be of any desired dimensions, and may be solid material as shown in FIGS. 1, 2, 6 and 7, or may be in the form of channel bars as generally indicated at 26 and shown in FIG. 4, or modified channel bars as indicated at 28 and shown in FIG. 5. Braces 14 are provided between side rails as shown in FIGS. 1 and 9. It being understood that any suitable bracing means may be used, for example, brace shown in FIG. 80f U.S. Pat. No. 2,727,671 and as shown in FIG. 1 of U.S. Pat. No. 1,341,707.

The novel arrangement of parts which provide a way to fold or collapse a ladder so that it occupies a minimum of space. The folding is accomplished by offsetting or positioning in different planes, every other rung 16 so that they fold by each other. The rungs 16 are in a plurality of rows and are pivotally at 18 and 20 where they are attached to the ladder side rails 10 and 12. The-rungs can fold down like a closing parallelogram until the rungs become substantially parallel to the side rails.

The folded length of the ladder becomes longer by approximately the length of a rung. The thickness of the folded ladder may be as low as the thickness of the side rails.

Rigidity of the ladder is provided by suitable brace or braces 14. In FIGS. 6 and 9 diagonally cross members form the bracing effect. One end of braces 14 is hinged at 19 and 21 where they are attached to the side rails 10 and 12', and the other ends of the braces 14 are provided with suitable fastening devices 22 and 24 for remobile attaching them to side rails 10 and 12. The fastening devices in a simple form may be a self-locking snap-in pin in a hole in the side rails. When the ladder is in the folded position the diagonal braces 14 are folded down along the edge of the side rail to which it is attached. It is to be understood that a locking mechanism may be placed on the end or ends of each rung for providing rigidity to the folding ladder. The rungs may be made of wood, metal, composition, solid or hollow and in suitable geometric shape to provide strength.

The ladder may be of any practicable length and extra sections may be attached to give the desired length. The ladder sections may vary in width whereby the equivalent ofa tapered ladder is provided.

In FIG. 3 are shown one means of pivotally attaching rungs 16 to the side rails 10 and 12. This means includes generally U-shaped cross-section and having their bottoms sections 26 solidly secured to the side rails 10 and 12. If desired U-shaped means may be constructed as an integral part of the side rails of the types shown in FIGS. 4 and 5. The rungs 16 have their end portions journaled on the shafts 28. Spacers 30 between the rungs l6 and the flanges 32.

As shown in FIGS. 4 and 5 the channel-like members have bottoms, side walls extending outwardly from the bottoms and rib-like members extending longitudinal of each channel and parallel to the side walls. The rib does not extend outwardly a distance greater than the side walls/The ribs may be interrupted between areas of rung attachments (See FIG. 4).

If additional section are to be employed to make a longer ladder, one of the extensions as shown in FIG. 8 is made as shown and is narrower than the first section. Aperatures or openings 33 and 34 are provided in one end of the extensions side rails. If desirable locking devices or pins 36 may be used to secure the sections of the ladder together. In use the extension, in the most extended position, the bottom part thereof should have the top rung of the ladder fit into the openings 33 and tially equal to distance between adjacent rungs in the first section of the ladder.

In FIG. 10 is shown the novel ladder and an extension used as a self supporting IadderJWhen the ladder. is used in this manner a removable braces 38 are used and a modified rung receiving means 40 is provided. In

this use and some other uses the extension section only may 'not have the rungs off-set, but in casses the rung spacing must be greaterthan the length of the rungs to nel-like members side rails; each of said rails having bottom, outwardly extending side walls and longitudinal extending rib-like member projecting from the bottom and being substantially parallel to side walls; one section of said ladder having one end of each channel-like side rails provided with one wall, part of bot tom and rib, extending the distance between-adjacent rungsin the other section, beyond the remainder of bottom and other sidewall, the bottoms of unequal length having rung receiving openings therein; rungs pivotally attached to side walls and ribs, adjacent rungs at-least in one section attached to side walls and ribs in different planes whereby on collapsing the rungs fold down between side walls and ribs and means for maintaining ladder in uncollapsed position.

2. A collapsible ladder according to claim 1, in which said channel-like members arebraced in opened position by brace pivotally attached at one end to said channels and opposed end of said brace detachable secured to another channels.

3. A collapsible ladderin accordance with claim 1, in which said means for maintaining ladder in uncollapsed position are cross members. i

Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4042991 *Jun 21, 1976Aug 23, 1977Suntech, Inc.Parallelogram structure
US4482029 *Jun 23, 1983Nov 13, 1984Prochaska William JTruck ladder
US4998982 *Dec 16, 1988Mar 12, 1991Arnold William FMetal ladder construction with reinforced side rails
US6145621 *Sep 2, 1997Nov 14, 2000Nye; John E.Boarding ladder for a boat bow
US6536558Feb 16, 2001Mar 25, 2003Harold E. PriceFolding ladder
US8191685 *May 16, 2011Jun 5, 2012Geiselman Iii Grover JFolding ladder
US20130048429 *Aug 31, 2011Feb 28, 2013Ardisam, Inc.Self-locking bi-foldable load bearing segment
EP0136904A2 *Oct 1, 1984Apr 10, 1985Reitzer, JosephCollapsible ladder
Classifications
U.S. Classification182/159, 182/178.4
International ClassificationE06C1/383, E06C1/00
Cooperative ClassificationE06C1/383
European ClassificationE06C1/383