US3024864A - Folding ladder - Google Patents

Description

March 13, 1962 T. E. PADLO FOLDING LADDER Filed Nov. 18

111V VENTOR. THe-MA i PA @L0 l] f ,4 rra@ Eys United tates Patent 3,024,864 FLDNG LADDER Thelma E. Padlo, Detroit, Mich., assigner, by mesne assignments, to B @e R Ladder Enterprises, Inc., Cleveland, Ohio, a corporation of Ohio Filed Nov. 1S, 1959, Ser. No. 853,938 4 Claims. (Cl. 182-160) The present invention relates to collapsible or folding ladders and, more particularly, to a folding ladder suitable for use as a lire escape.

An important object of the present invention is to provide a new and an improved folding or collapsible ladder construction to provide a high-strength ladder which folds to occupy a smaller space than that heretofore occupied by ladders of similar dimensions when unfolded.

Another object of the present invention is to provide a folding or collapsible type ladder in which the rungs are connected to side members by pivoted connections so that the side members can be moved toward each other to fold or collapse the ladder, the ladder being so constructed and arranged that the rungs and side members may be in a common plane and so that the length of the rungs may be such that the rungs can overlap when the ladder is folded without detrimentally limiting the folding movement of the ladder.

A further object is to provide a ladder where one side member receives the other side member in folding.

In accordance with the present invention, the ladder comprises a pair of spaced vertical side members to which the rungs of the ladder are pivoted at their opposite ends. The side members are preferably channelshaped and enclose the rungs when folded, with one side member being received in the other. The rungs can swing about the pivots to allow the side members to be moved toward each other to fold the ladder. The rungs are channel-shaped and are tapered proceeding from one side member to the other to provide a rung of progressively smaller width as one proceeds from the one side member to the other enabling the adjacent rungs to nest into each other, the smaller portions of the rungs being received by the larger portions of the adjacent rungs when the ladder is in a folded position. This permits the rungs to be longer than the spacing between adjacent rungs. Furthermore, the pivotal connections for the ends of the rungs are such that the pivots do not interfere with the nesting of the rungs and, preferably, the connections at the smaller ends of the rungs each comprises a post which extends inwardly from the adjacent side member and which is received in the channel of the rung with the channel being connected thereto by a pivot pin which passes through the sides of the channel.

Further advantages and objects of the present invention will be apparent from the following detailed description of the preferred embodiment made with reference to the accompanying drawings forming a part of the present specification and in which:

FIG. 1 is a front elevational view of a ladder embodying the present invention;

FIG. 2 is a view of the ladder of FIG. l shown in a folded condition;

FIG. 3 is a fragmentary view looking at the left-hand side of the ladder as shown in FIG. 2 with portions thereof cut away;

FIG. 4 is a sectional view taken approximately along line 4-4 of FIG. 2;

FIG. 5 is a sectional view taken approximately along line 5-5 of FIG. 2; and

FIG. 6 is a sectional View taken approximately along line 6 6 of FIG. 1. v

Referring to the drawings, FIG. 1 shows a ladder embodying the present invention, while FIG. 2 shows the rice ladder in a folded condition. As is shown in the drawings, the ladder comprises rungs 10 which are pivoted at opposite ends to vertical side members or channels 11, 12. The side members 11, 12 are channels, U-shaped in cross section with the open side facing the opposite side member. The sides of the channels of the side members 11, 12 are designated by reference numerals 13 and the bottoms of the channels by the reference numerals 13a. The rungs 1li each have one end received in the channel of side member 11 and each are pivoted to the side member 12 by pivots 14. The rungs 1i) are also channel-shaped with the open side facing downwardly, the sides of the channel of each rung being designated by the reference numeral 15 and the bottom, which forms the top of the rung, by the reference numeral 16. A pivot 14 connects each side 15 of the rung to the adjacent side member 13 and each comprises a pin that passes through the corresponding side 15 of the corresponding channel-shaped rung 10 and the adjacent side 13. The pivots 14 have flat heads 14a disposed in the channels of the rungs.

The rungs 10 are also each pivoted to the side member 11; and to this end, the end of the rungs 10 adjacent the member 11 are received in the channel of' the side member 11 and a post 2d is fixed to the bottom 13a of the channel of the side member 11 adjacent each of the rungs 10 and extends horizontally outwardly from the bottom to be received in the channel of the corresponding rung. The corresponding rung 10 is pivoted to the adjacent post 20 by a pin 21 which passes through the sides 16 of the rung and through the corresponding post 20. It will be noted that the pins 21 do not extend appreciably outwardly of the outer sides of the rungs 1i), for a reason which will be pointed out hereinafter.

As is best shown in FIGS. 3 and 6, the rungs are each tapered proceeding from their ends adjacent the side member 12 to their ends adjacent the side member 11, so that the width of the rung becomes progressively smaller when proceeding from right to left as the rung is viewed in FIGS. 2 and 6. The tapered length of the rungs 10 permits the narrower ends of the rungs to be received or nested in the larger portions of the adjacent rung disposed thereabove when the ladder is folded to the position of PiG. 2. To permit nesting the taper on the rungs must be such that when the ladder is folded, the inside dimension of each channel at the point adjacent the narrow end of the next lower rung must be slightly larger than the outside dimension of the narrow end of the rungs. 'If the rungs were not tapered to permit nesting, the pivotal connections of the rungs to the side channels 11, 12 would have to be spaced a distance equal to the length of the rungs 10 in order to eliminate interference of the rungs with each other and to permit the maximum folding of the ladder. Alternately, the rungs might be offset from each other, 'out this presents complications in the construction of the ladder. It will also be noted that the use of a post pivot for the smaller end of the rungs 10 and the use of two pivots 14 each with a dat head 14a for the larger end of the rung permits the nesting without interference between the pivot pins for connecting the rungs 10 to the side members 11, 12 and the sides of the receiving rung.

The nesting of the rungs allows the side members or channels 11, 12 to be pivoted until the members meet each other even though the rungs are longer than the spacing between their pivots. In the preferred and illustrated embodiment, the vertical side channel member 11 is formed so that portions of the sides 13 overlie the sides 13 of the channel member 12 when the ladder is folded to provide protection from the weather for the pivots and rungs. As is shown in the drawings, the Sides 13 of the channel member 11 define an obtuse angle with the bottom 13a of the channel member 11 and diverge away annessa from each other proceeding outwardly from the bottom of the channel. The outer edge portions 13b of the sides 13 of the member 11 are bent to extend perpendicularly to the plane of the bottom of the channel and are spaced so that the sides 13 of the channel member 12 may be received between the edge portions of the sides 13 of the channel member 11. Thus, when the ladder is folded, the edge portions overlie the sides of the channel member 12 and protect the rungs and pivots from weather.

In the preferred embodiment, a plurality of detent springs 29 are secured to the inside of the bottom of the channel 12 and, when the ladder is folded, extend through openings 3() in the adjacent rungs, The detent springs are disposed to resiliently engage the small end of the rung which nests into the rung through which the spring extends, as is shown in FIG. 2, to hold the ladder in a closed position. Any other suitable construction may be utilized to hold the ladder closed. it will be understood that by pulling the side channels 11, 12 apart, the rungs will pivot and the side channels can be moved to a spaced position, as shown in FIG. 2.

Preferably, the channel member 11 is shorter than the channel member 12 and when the ladder is unfolded, the lower end thereof is level with the lower end of the channel member 12. When the ladder is folded, the channel member 11 is moved upwardly and the top thereof is disposed adjacent the top of the channel member 12 and a cap 32 may be provided to eliminate rain, etc., from the top of the ladder.

The ladder is particularly suitable for use as a fire escape ladder and to this end the side member 12 can be secured to the side of a building with the lower end thereof resting on the ground. When the ladder is folded, the ladder will appear as an ordinary downspout and not detract from the appearance of the building. Furthermore, locks may be provided so that the ladder can only be opened at access points above the ground, thereby eliminating the possibility the ladder would be unfolded at ground level by an intruder.

It can now be seen that the present invention is a rigid folding ladder which can be folded to occupy a smaller space than occupied by other ladders of similar strength and dimensions. Furthermore, the constructionl of the ladder is such to protect the rungs and pivots from the weather when the ladder is folded.

While the preferred embodiment has been described in considerable detail, further constructions, modifications, and arrangements will be apparent to those skilled in the art and it is'hereby my intention to cover such construe tions, modifications, and arrangements which fall within the ability of those skilled in the art and within the scope and spirit of the present invention.

What I claim is:

l. A folding ladder comprising spaced vertical side members, a plurality of rungs extending between the members in vertically spaced relationship, pivotal connections connectiug each of said rungs to each of said side members, said rungs each having a channel shape with the open side of the channel facing downwardly and the bottom of the channel providing the top of the rung, said rungs being tapered from a given width adjacent one of said side members to a narrower width adjacent the other of said side members, and said rungs being spaced from each other a distance less than the length of the rungs and the wider portion of each rung receiving the narrower portion of the adjacent rung upon the swinging of said rungs about said connections to move said members toward each other.

2. A ladder as defined in claim 1 wherein the pivotal connections to the side member at the narrow end of the rungs comprise a post fixed to the side member and received in the channel of the rung and a pivot pin extending from the sides of the rung channel and through the post.

3. A folding ladder comprising spaced vertical side members, a plurality of rungs extending between the members in vertically spaced relationship, pivotal connections connecting each of said rungs to each of said side members, said rungs each having a channel shape with the open side of the channel facing toward one end of said side members, said rungs being tapered from a given width adjacent one of said side members to a narrower width adjacent the other of said side members, and said rungs being spaced from each other a distance less than the length of the rungs and the wider portion of each rung receiving the narrower portion of the adjacent rung upon the swinging of said rungs about said connections to move said side members toward each other.

4. In a folding ladder comprising spaced vertical side members, a plurality of rungs extending between the members in vertically spaced relationship, pivotal connection connecting each of said rungs to said side members whereby said side members may be moved toward each other by swinging said rungs about Said pivotal connections, the spacing between said rungs being less than the length of said rungs and when said side members are moved toward each other said rungs move to a nested position overlapping each other and extending generally lengthwise of said side members, the rungs of said ladder intermediate the end rungs thereof having narrow portions adjacent one side member and wide portions adjacent the other side member, with the narrow portions of the intermediate rungs lapping the wide portions of the adjacent rungs displaced toward one end of the ladder when said side rungs are in their nested position, the narrow portions which lap the wide portions when said rungs are in nested position being received in channels in the rungs lapped thereby, and the end rung of said ladder at said one end having a channel receiving the narrow portion of the adjacent rung and the end rung at the other end of said ladder being received in a channel in the adjacent rung when said rungs are in nested position.

References Cited in the le of this patent UNITED STATES PATENTS Re. 2,735 Wyatt Aug, 20', 1867 1,783,686 Williams Dec. 2, 1930 2,492,511 Yehling Dec. 27, 1949

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