US3861499A

US3861499A - Folding ladder

Info

Publication number: US3861499A
Application number: US253801A
Authority: US
Inventors: Jr John O Follett
Original assignee: Individual
Current assignee: Individual
Priority date: 1972-05-16
Filing date: 1972-05-16
Publication date: 1975-01-21
Anticipated expiration: 1992-01-21

Abstract

A ladder construction which may be folded up into a compact configuration requiring comparatively little storage space. The ladder is composed of a plurality of sections hinged together at their ends for folding in accordion fashion. Before the ladder is folded, each section is flattened out by swinging the side rails outwardly around their connections with the attaching rungs. The side rails are held in non-flattened, operative position by cross members releasably preventing the outwardly swinging movement. The hinges are mounted in such position on the side rails that they are inoperative to permit folding of the ladder sections in accordion fashion when the side rails are in the non-flattened, operative position. Quick release latching devices providing positive attachment are provided on the cross members and between adjacent ladder sections.

Description

United States Patent 11 1 Follett, Jr.

[ 51 Jan. 21, 1975 FOLDING LADDER [76] Inventor: John O. Follett, Jr., 555 Valley View Dr., Medford, Oreg. 97501 22 Filed: May16,1972

21 Appl. No.2 253,801

Primary ExaminerReinaldo P. Machado Attorney, Agent, or Firm-Schapp & Hatch [57] ABSTRACT A ladder construction which may be folded up into a compact configuration requiring comparatively little storage space. The ladder is composed of a plurality of sections hinged together at their ends for folding in accordion fashion. Before the ladder is folded, each section is flattened out by swinging the side rails outwardly around their connections with the attaching rungs. The side rails are held in non-flattened, operative position by cross members releasably preventing the outwardly swinging movement. The hinges are mounted in such position on the side rails that they are inoperative to permit folding of the ladder sections in accordion fashion when the side rails are in the non-flattened, operative position. Quick release latching devices providing positive attachment are provided on the cross members and between adjacent ladder sections.

11 Claims, 9 Drawing Figures PATENTEB 3.86 1.499

saw 3 OF 3 FOLDING LADDER BACKGROUND OF THE INVENTION This invention relates to a FOLDING LADDER more particularly to ladders which can be folded up into a compact unit for storage.

Because of the long, slender nature of the ordinary ladder, it is often difficult to store when not in use. Various attempts have been made to provide a ladder which will fold up in some manner into a compact unit which can be stored more easily. In many of these structures, all or some of the rungs are detachable from the side rails to permit the particular folding action. The resulting loose pieces are often subject to loss while being stored.

Other previous folding ladders have proposed forming the ladder in a plurality of sections hinged together so they can be folded up something like the bellows of a accordion. An example of such structure is illustrated in US. Pat. No. 3,081,840 issued to William R. Hire on Mar. 19, 1963. While the accordion-folding construction is an improvement over other folding ladders, it still leaves much to be desired, particularly in connection with modern light metal alloy ladders made of aluminum alloys and the like.

Aluminum alloy ladders normally have rather deep side rails to increase the load-bearing ability of the ladder. Typically, an aluminum ladder 14 feet long will be approximately 14 inches wide and cylindrical rungs of 1 /2 inches outside diameter. The side rails may be about three-fourths wide and 2% or more inches deep. Normally, the side rails are structural shapes, such as a channels having top and bottom flanges connected by a vertical web. Because of the significant depth of such side rails, merely folding the ladder is accordion fashion does not provide the desired compactness for most efficient storage.

In the present invention, the rungs of the ladder are moved from their normal position halfway between the top and bottom flanges of the side rails to a position spanning the space between the upper flanges. The rungs are operatively connected to the side rails in such manner that the side rails may be swung outwardly to a flattened position so that the several sections will occupy a minimum volume of storage space when folded in accordion fashion. Means is provided for holding the sections in non-flattened position and for securing the sections against being folded when the structure is in use as a ladder.

A principle object of the invention, therefore, is to provide a folding ladder in a plurality of sections, each of which may be flattened by swinging the side rails outwardly and thereafter may be folded in accordion style into a compact unit for storage.

Another object of the invention is to provide a folding ladder of the character described which is of a strong and sturdy construction particularly adapted to the use of light metal alloys.

A further object of the present invention is to provide a folding ladder structure of the character set forth which contains relatively few machined parts and has no detachable elements which could be lost during storage.

A still further object of the invention is the provision, in a folding ladder of the character described, of a novel pivot connection between the rungs and the side rails which permit the described swinging of the side rails to flattened position without the use of separate hinges.

Other objects and features of the invention will become apparent from the specification and claims herein.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a perspective view of a folding ladder constructed in accordance with the present invention and shown in operative position for use as a ladder.

FIG. 2 is an enlarged fragmentary cross-sectional view faken substantially on the plane of line 2-2 of FIG. 1.

FIG. 3 is a fragmentary cross-sectional view taken substantially on the plane of line 3-3 of FIG. 2.

FIG. 4 is a perspective view of the ladder of FIG. 1 illustrated how it is made in sections and the manner in which the sections are folded in accordion fashion for storage.

FIG. 5 is a perspective view of the ladder of FIG. 4 in its folded, storage position.

FIG. 6 is an enlarged typical cross-sectional detail view through a side rail and associated portion of a rung, of the ladder of FIG. 1, illustrating the manner in which the side rail is moved to a folded position.

FIG. 7 is a fragmentary bottom plan view of a portion of the ladder of FIG. 1.

FIG. 8 is an enlarged perspective detailed view of a quick-connection attaching device forming part of the structure illustrated in FIG. 7; and

FIG. 9 is an enlarged fragmentary perspective detailed view of a quick-connecting latch structure forming a part of the ladder illustrated in FIG. 7.

The folding ladder of the present invention basically includes a plurality of ladder sections A, B and C formed for securing in end-to-end relation to provide the ladder ll, hinge means 12 on the ladder sections A, B and C formed for holding same in such end-to-end relation and permitting folding together of such ladder sections in accordion fashion, and retaining means 13 on the ladder sections formed for selectively securing same in unfolded relation. Each of the ladder sections A, B and C has spaced

side rails

14 and 16, a plurality of parallel rungs l7 operatively connected between the

side rails

14 and 16 with freedom of movement to permit swinging of the side rails between an operative position for use as a ladder, see FIG. 2, and a relatively flattened position facilitating the folding together of the ladder sections in the accordion fashion illustrated in FIG. 4.

Most aluminum alloy ladders position the rungs midway between the top and bottom surfaces of the side rails, with the ends of the rungs being swaged in holes formed in the web 18 of the side rail. In the present invention, the rungs 17 are positioned to span the space between the upper flanges 19 of the side rails. With this positioning of the rungs l7, swinging of the side rail around its operative connection with the end of the rung in a clockwise direction, as viewed in FIG. 6, provides a substantially flattened configuration of the section, and this permits the sections A, B and C to be folded together more closely than would be possible if the side rails were allowed to remain in the non-folded position illustrated in FIG. 2.

It should be noted that the pivotal operative connections between the ends of the rungs l7 and the side rails are positioned at the upper areas of the

side rails

14 and 16. In other words, the side rails are oblong in crosssectional aspect with the longer dimension of the oblong normal to the plane in which the rungs 17 lie when the side rails are in their operative, non-flattened position for use as a ladder. The longer dimension of the cross-section of each side rail in parallel and adjacent to the plane in which the rungs 17 lie when the side rails are in their flattened position so that, in effect, the side rails continue outwardly from the ends of the rungs.

When the ladder is constructed of aluminum alloy, or the like, the

side rails

14 and 16 will normally be in the form of extruded or rolled structural shapes having relatively

narrow walls

19 and 21 at top and bottom joined together by a wider wall or web 18. Preferably, the ends of rungs 17 are pivotally connected to the upper of the relatively narrow walls in position to provide the described swinging action of the side rails to flatten out the ladder sections. As here shown, the

side rails

14 and 16 are elongated channels having top flanges 19 and bottom flanges 21 joined by a vertical connecting web 18, with the

flanges

19 and 21 turned outwardly.

In accordance with the present invention, the operative connections between the ends of the rungs 17 and the associated

side rails

14 and 16 provide a pivotal action permitting swinging movement of the side rails, in the manner shown in FIG. 6, upwardly into substantially coplaner relationship with the rungs 17. The operative pivotal connections may comprise hinges or similar pivot devices. However, for reasons of economy and ease of production, the construction illustrated in the drawings is preferred. As there shown, the ends of rungs 17 are flattened to provide tongue members 22 slidably received in longitudinally extending slots 23 formed in the top flanges 19.

The tongue members 22 are bent in a reverse curve so as to permit the described swinging movement of the side rails between their operative and flattened positions, with the rungs 17 being connected to the

side rails

14 and 16 at all times. Preferably, the rungs 17 are of tubular form flattened at their ends to provide the tongue members 22 and the curvature of the tongues 22 is continued around to slidably engage the outer edge of flange 19. The extreme end of the tongue member is curled back on itself after assembly of the rungs and side rails to provide a tubular portion 24 capable of retaining the tongue members 22 in the slots 23.

As here shown, the retaining means 13, which prevents folding of the ladder while in use, includes forming the hinge means in such manner that the sections A, B and C cannot be folded in accordion fashion so long as the

side rails

14 and 16 are in their abovedescribed operative position extending normal to the plane of the rungs 17. The retaining means 13 also includes positive-action, quick-disconnect fasteners 26 adjacent to the hinge means 12, at the confronting ends of the ladder sections A, B and C.

The fasteners 26 are here shown as comprising bars 27 pivoted at one end 28 to an end of one of the

side rails

14 and 16, and having a hook portion 29 selectively engageable with pin 31 secured to the confronting end of the contiguous side rail. preferably, a pivoted, curved retaining member 32 is provided on the hook portion 29 for positively securing the ladder over the pin 31 while the ladder is in use.

In accordance with the present invention, locking means 33 is mounted on the ladder sections A, B and C and is formed for releasably securing the side rails 14 and 16 against the described swinging movement around their operative connections with the rungs 17, so as to selectively secure the side rails in their operative position, shown in FIG. 2, while the ladder is in use. As here shown, the locking means 33 includes elongated restraining members releasably connecting the side rails against the described swinging movement to their flattened position. Two forms of these restraining members are illustrated in the drawings. In one form, a cross bar 34 is pivoted atone end 36 to one of the side rails 14 and has a hook portion 37 selectively engageable over a pin 38 secured to the other side rail 16. A retainer or keeper 32 is pivotally attached to the hook portion 37 for selectively securing the hook on the pin 38.

The other form of restraining member illustrated may best be seen in FIGS. 7 and 9 of the drawings. As there shown, these restraining members comprise flexible cables 41 secured at one of their ends 42 to the side rails 14 and 16. The other ends 43 are secured to quickdisconnect and takeup devices 44, see FIG. 9.

The devices 44 include a bar member 46 pivoted on pin 47 secured to the web 18 of one of the side rails. Swinging of bar 46 to the position illustrated in FIG. 9 of the drawings serves to pull the associated cable taught, and bar 46 is held in this position by a latch member 48 pivotally secured by brackets 49 to side rail web 18. The latch 48 is held in engaged position on the end of bar 46 while the ladder is in use by a keeper 51 pivoted on pin 52 secured to web 18. When it is desired to fold up the ladder, keeper 51 is moved in the direction of arrow 53 allowing handle 54 of latch member 48 to be depressed, freeing bar 46 to swing around its pivot pin 47 and allow cable 41 to slacken.

W nthfiab q 9. are xar ssdin t e miss-cross configuration illustrated in FIG. 7 of the drawings, the cables 41 not only restrain

side rails

14 and 16 against swinging movement to their flattened position, but also provide diagonal bracing to strengthen the ladder assembly against racking movement. Further reinforcement may be provided by abutment members 56 secured to the rungs 17 adjacent to the tongue members 22 in position to intercept and halt swinging movement of the side rails 14 and 16 from their flattened position to the operative position illustrated in FIG. 2 of the drawings.

From the foregoing, it will be seen that the folding ladder of the present invention provides a structure which can be folded into a comparatively compact unit and which is simple and sturdy in construction and lends itself well to fabrication from light alloy metals.

I claim:

1. A folding ladder, comprising a plurality of ladder sections formed for securing in end to end relation to provide a ladder;

hinge means on said ladder sections formed for holding same in such end to end relation and permitting folding together of said ladder sections in accordion fashion;

retaining means on said ladder sections formed for selectively securing same in unfolded relation; each of said ladder sections having spaced side rails,

a plurality of parallel rungs operatively connected between said side rails with freedom of movement to permit swinging of the side rails between an operative position wherein said side rails are continuous for use as a ladder and a relatively flattened position so as to facilitate said folding together in accordion fashion;

said side rails being oblong in cross-sectional aspect with the longer dimension of the oblong normal to the plane of said rungs when said side rails are in said operative position and parallel and adjacent to said plane when said side walls are in said flattened position;

said side rails having relatively narrow walls joined by a wider wall;

and said rungs being formed with a pivotal connection to one of said relatively narrow walls.

2. A folding ladder as described in claim 1, and wherein said side rails are in the shape of elongated channels having top and bottom flanges and a connecting web, and said rungs have a pivotal connection to said top'flanges.

3. A folding ladder as described in claim 2, and wherein said pivotal connection comprises a flattened portion at each end of each rung, and slots in said top flanges formed for slidably receiving said flattened portions, said flattened portions being bent in a reverse curve so as to permit said swinging movement of said side rails between said operative and flattened positions.

4. A folding ladder as described in claim 3, and wherein said rungs are of tubular form with flattened ends to provide said flattened portions.

5. A folding ladder as described in claim 2, and wherein said hinge means is formed to permit said swinging movement only when said side rails are in said flattened position and to prevent said swinging movement when said side rails are in said operative position.

6. A folding ladder as described in claim 5, and wherein locking means is provided on said ladder sections formed for releasably securing said side rails against said swinging movement.

7. A folding ladder, comprising a plurality of ladder sections formed for securing in end to end relation to provide a ladder;

a plurality of parallel rungs operatively connected between said side rails with freedom of movement to permit swinging of the side rails between an operative position wherein said side rails are continuous for use as a ladder in a relatively flattened position so as to facilitate said folding together in accordion fashion;

said side rails having relatively narrow walls joined by a wider wall; and said rungs being formed with a pivotal connection to one of said relatively narrow walls; locking means on said ladder sections for selectively securing said side rails in said operative position;

said locking means comprising elongated restraining members releasably connecting said side rails against said swinging movement when in said operative position;

said rungs being positioned in substantially a common plane;

said side rails being oblong in cross-sectional aspect with the longer dimensions of the oblong normal to said plane when said side walls are in said operative position and parallel and adjacent to said plane when said side walls are in said flattened position;

quick release fasteners on said retaining members and said side rails for providing releasable connection therebetween;

said restraining members being connected between said side rails in spaced relation to the operative connections of said side rails to said rungs;

said side rails being in the shape of elongated channels having top and bottom flanges and a connecting web;

said rungs having a pivotal connection to said top flanges;

and said restraining members being releasably connected between said webs.

8. A folding ladder as described in claim 7, and wherein said restraining members are flexible and are attached at one end to one of said side rails, and quick release fasteners are carried on the other of said side rails and are formed for engaging the free ends of said restraining members and pulling the latter taut.

9. A ladder construction, comprising a pair of spaced side rails,

a plurality of rungs having operative connection to said side rails and extending in parallel spaced relation therebetween,

said side rails each having a depth exceeding its width,

said operative connections being formed to provide for selective movement of said side rails into an operative position wherein said side rails are continuous in form with said depth normal to said rungs for use as a ladder and a relatively flattened position with said depth aligned with said rungs for storage;

said operative connections being formed to provide pivotal movement between said rungs and said side rails between said operative and flattened positions;

said operative connections each comprising a curved tongue on an end of one of said rungs slidably engaged in a slot formed in the adjacent one of said side rails.

10. A ladder construction as described in claim 9, and wherein each of said tongues is formed to engage said side rails and prevent removal of said tongue from said slot.

11. A ladder construction, comprising a pair of spaced side rails, and a plurality of rungs having operative connection to said side rails and extending in parallel spaced relation therebetween, said side rails each having a depth exceeding its width, said operative connections being formed to provide for selective movement of said side rails into an operative position wherein said side rails are continuous in form with said depth normal to said rungs for use as a ladder and a relatively flattened position with said depth aligned with said rungs for storage, said side rails comprise elongated channel members having relatively narrow top prises a plurality of elongated flexible members, a plurality of quick release fasteners formed for releasably connecting said elongated flexible members between said side rails and said operative connections each comprise a curved tongue on an end of one of said rungs slidably engaged in a slot formed in the adjacent one of said side rails, said slot being formed in said top flanges of said sidewalls.

Claims

1. A folding ladder, comprising a plurality of ladder sections formed for securing in end to end relation to provide a ladder; hinge means on said ladder sections formed for holding same in such end to end relation and permitting folding together of said ladder sections in accordion fashion; retaining means on said ladder sections formed for selectively securing same in unfolded relation; each of said ladder sections having spaced side rails, a plurality of parallel rungs operatively connected between said side rails with freedom of movement to permit swinging of the side rails between an operative position wherein said side rails are continuous for use as a ladder and a relatively flattened position so as to facilitate said folding together in accordion fashion; said side rails being oblong in cross-sectional aspect with the longer dimension of the oblong normal to the plane of said rungs when said side rails are in said operative position and parallel and adjacent to said plane when said side walls are in said flattened position; said side rails having relatively narrow walls joined by a wider wall; and said rungs being formed with a pivotal connection to one of said relatively narrow walls.

2. A folding ladder as described in claim 1, and wherein said side rails are in the shape of elongated channels having top and bottom flanges and a connecting web, and said rungs have a pivotal connection to said top flanges.

7. A folding ladder, comprising a plurality of ladder sections formed for securing in end to end relation to provide a ladder; hinge means on said ladder sections formed for holding same in such end to end relation and permitting folding together of said ladder sections in accordion fashion; retaining means on said ladder sections formed for selectively securing same in unfolded relation; each of said ladder sections having spaced side rails, a plurality of parallel rungs operatively connected between said side rails with freedom of movement to permit swinging of the side rails between an operative position wherein said side rails are continuous for use as a ladder in a relatively flattened position so as to facilitate said folding together in accordion fashion; said side rails being oblong in cross-sectional aspect with the longer dimension of the oblong normal to the plane of said rungs when said side rails are in said operative position and parallel and adjacent to said plane when said side walls are in said flattened position; said side rails having relatively narrow walls joined by a wider wall; and said rungs being formed with a pivotal connection to one of said relatively narrow walls; locking means on said ladder sections for selectively securing said side rails in said operative position; said locking means comprising elongated restraining members releasably connecting said side rails against said swinging movement when in said operative position; said rungs being positioned in substantially a common plane; said side rails being oblong in cross-sectional aspect with the longer dimensions of the oblong normal to said plane when said side walls are in said operative position and parallel and adjacent to said plane when said side walls are in said flattened position; quick release fasteners on said retaining members and said side rails for providing releasable connection therebetween; said restraining members being connected between said side rails in spaced relation to the operative connections of said side rails to said rungs; said side rails being in the shape of elongated channels having top and bottom flanges and a connecting web; said rungs having a pivotal connection to said top flanges; and said restraining members being releasably connected between said webs.

9. A ladder construction, comprising a pair of spaced side rails, a plurality of rungs having operative connection to said side rails and extending in parallel spaced relation therebetween, said side rails each having a depth exceeding its width, said operative connections being formed to provide for selective movement of said side rails into an operative position wherein said side rails are continuous in form with said depth normal to said rungs for use as a ladder and a relatively flattened position with said depth aligned with said rungs for storage; said operative connections being formed to provide pivotal movement between said rungs and said side rails between said operative and flattened positions; said operative connections each comprising a curved tongue on an end of one of said rungs slidably engaged in a slot formed in the adjacent one of said side rails.

11. A ladder construction, comprising a pair of spaced side rails, and a plurality of rungs having operative connection to said side rails and extending in parallel spaced relation therebetween, said side rails each having a depth exceeding its width, said operative connections being formed to provide for selective movement of said side rails into an operative position wherein said side rails are continuous in form with said depth normal to said rungs for use as a ladder and a relatively flattened position with said depth aligned with said rungs for storage, said side rails comprise elongated channel members having relatively narrow top and bottom flanges connected by a wider web, and wherein said operative connections are formed to provide pivotal movement between said rungs and side rails between said operative and flattened positions, with locking means provided on said sidewalls for releasably securing the parts in said operative position, said locking means comprises a restraining means releasably connecting said side rails so as to prevent said pivotal movement from said operative position toward said flattened position, said restraining means comprises a plurality of elongated flexible members, a plurality of quick release fasteners formed for releasably connecting said elongated flexible members between said side rails and said operative connections each comprise a curved tongue on an end of one of said rungs slidably engaged in a slot formed in the adjacent one of said side rails, said slot being formed in said top flanges of said sidewalls.