US3428146A - Ladder having telescoping section - Google Patents

Description

Feb. 18, 1969 R. 1. BAIR 3,428,146

LADDER HAVING TELESCOPING SECTION iled May 16, 1967 INVENTOR. Rouse/2 I. 54212 ArToQMEY United States Patent 3 Claims ABSTRACT OF THE DISCLOSURE A ladder comprising two sections connected to one another, each section having step means to enable that section to be ascended and descended, the step means of one section being mounted therewith to afford movement of the step means from a position of use to a position of non-use or inaccessibility, thereby to render that section unusable. Preferably, the movement of the movable step means is a sliding action longitudinally of the section with respect to which the step means is mounted.

Background of the invention A general ladder construction that has been quite popular comprises two sections connected together at one end to form substantially an inverted V. One of the sections has steps to enable that section to be ascended or descended. The popularly termed step-ladder results when such sections are pivotably connected and therefore can be selectively folded together as for storage.

Several modifications of this general ladder construction have previously been suggested. For example, prior modifications have included a stepladder construction wherein one of two sections of the ladder may be further extended as by a telescoping part. In all of such known cases, this extension is for the purpose of enabling the user to reach a higher elevation. As instances, US. patent, No. 1,836,163 to Goode and No. 2,926,746 to St-Mars disclose ladder constructions of this type. In all of such structures, the extension serves the function of ma king additional steps available, so that the user can climb to a higher position. None embodies actually removing steps from the lower elevation so as to make the ladder inoperative.

Summary of the invention.

In some applications of use for a generally inverted V-shaped ladder, it is desired to render the ladder inoperative at certain times. A common example of such an application is the use of a ladder for a portable swimming pool popularly adapted for erection on a lawn. Such a pool normally has a rubbery, flexible flooring secured to an upstanding cylindrical wall. In order to provide a means of ingress and egress with respect to the pool, the two sections of an inverted V-shaped ladder are placed on opposite sides of the cylindrical wall.

At times, it is necessary to guard against unwanted use of the ladder and pool. For instance, in the absence of suitable supervision, use by small children should be prevented as a matter of safety. Further, vandalism can be discouraged by preventing ready access to the interior of the pool.

These and related objects are realized by the present ladder in having the step means of one section mounted so as to be movable between a position of use and a position of non-use or inaccessibility. In the preferred form, this is accomplished by having the steps of such a section bodily transferable with respect to that section so as to put the steps beyond ready reach of a potential user.

Brief description of the drawing The accompanying drawing illustrates the present invention wherein:

FIGURE 1 is an isometric view of one form of the present ladder;

FIGURE 2 is a view similar to FIGURE 1 but on a reduced scale and shows the steps of one section of the ladder moved to an inoperative position;

FIGURE 3 is a section of FIGURE 2 on the line IIIIII and illustrates retainer or lock means used to hold the step means of one section in a position of inaccessibility; and

FIGURE 4 is a section similar to FIGURE 3 and shows a modified form of a retainer.

Description of the preferred embodiments In general, the present ladder comprises two sections secured adjacent one end to each other to define an inverted V-shape. Each section has steps to aid in climbing or descending that section. The steps of one section may be shifted to a non-operative position and preferably held there by a suitable lock or retainer.

Referring to the drawing, the embodiment illustrated by FIGURES 1 through 3 comprises ladder sections generally indicated at 10 and 11. The sections are joined together at a common end by cross-braces 12 bolted to and extending between side rails 13 of section 10 and side rails 14 of section 11. Channel runners 16 (FIGURE 3) of U-shape cross-section are fixed to and extend between the facing edges of each of the rails 13 and 14 and receive a platform 17. The platform normally comprises several planks of wood placed side-by-side in the channel runners 16. The platform 17 provides footing as for diving into a pool and also supplies a base for firm footing when entering or leaving a pool.

A continuous, looping, tubular handrail 18 is also fixed to and extends between each of the opposed rails 13 and 1 4 and is bolted thereto. The handrail facilitates crossing from one section of the ladder to the other. At the diverging ends of the sections 10 and 11, the rails 13 and 14 may be suitably secured to a wooden base plate 19 as by an angle 20 bolted to each connecting part.

The side rails of section 14 are preferably U-shaped beams, preferably of extruded aluminum, and have a plurality of steps or treads 21 extending therebetween. The steps 21 may also be U-shaped in cross section, the flanges thereof being bolted to the flanges of the rails 14 and reinforced as by braces 22. The side rails 13 of section 10 are also U-shaped beams, preferably of extruded aluminum, and contain inner sliding rails 23 of identical construction. The inner rails 23 have substantially an I-shape in crosssection, the exposed ends of the I having a flange bead. This bead partially encircles the adjacent edges of the rails 13 (FIGURE 3) to. enhance a free sliding action. A series of interconnecting steps 24 are spaced along the length of and interconnect the inner rails 23. The steps 24 may be of the same U-shaped cross-section as the steps 21 with the flanges fixed to the flanges of the rails 23, as the flanges of steps 21 are secured with respect to the rails 14.

When the inner rails 23 are lifted relatively to the outer rails 13, the steps 24 naturally follow. In order to hold the rails 23 and steps 24 in an elevated position suitable locking or retainer means are employed. Conveniently, such means are located on the platform 17 which is in close proximity to the rails 23 and interconnecting steps 24. In one form, the retainer may take the form of an L-shaped lug 25 (FIGURE 3), the longer stern of which is suitably secured as by bolts to the underside of the platform 17, and the shorter stem of which has a suitable opening 27. At least the bottommost of the steps 24 and preferably several or all of such steps have a cooperating, apertured lug 28 fixed centrally of the steps and in vertical alignment with lug 25.

In use, when it is desired to render the ladder inoperative, the rails 23 are lifted as by the steps 24 and elevated with respect to the base plates 19. Any step 24 which has 2. lug 28 is raised to a point opposite to the opening in lug 25 as illustrated by FIGURE 3. A suitable lock, such as a padlock 29 as in FIGURE 2, may be passed through the aligned openings of lugs 25 and 28 and thereby fix the lugs together. This, in turn, maintains the rails 23 and steps 24 in a position of inaccessibility as shown by FIGURE 2. When it is desired to place the ladder in use, the padlock 29 is opened and the rails 23 and steps 24 allowed to descend by their own weight preferably to rest upon a base plate 19. Thereafter the ladder may be used as before.

In place of the padlock 29, any suitable retainer means may be used. FIGURE 4 illustrates a modification wherein a sliding bolt retains the telescoping rails 23 in an elevated position. In this case, a bolt 30 moves reciprocably in the direction of its length through the apertured legs of two lugs 31 and 32 fixed to the under side of the platform 17. A handle 33 enables a user so to move the bolt 30 and also acts as a stop to prevent the bolt from sliding completely through the lugs 31 or 32. When the rails 23 and steps 24 are raised, the bolt 30 engages an opening in a lug 28, as shown in FIGURE 4, to retain the inner rails 23 and steps 24 in a position of inaccessibility.

The safety innovation afforded by the movable rails 23 prevents children from ascending the ladder at times of no supervision. Although various movements of the rails are contemplated, it is much preferred that these rails slide longitudinally of or telescope the outer rails 13 rather than pivot thereabove. The preferred sliding or telescoping mounting eliminates swinging the movable section through a large angle of 180 degrees and, moreover, eliminates the possibility of inadvertently dropping the movable section on a user, particularly a child. Further, by a sliding arrangement, the inner rails 23 can be locked or retained with respect to section 10 at any tread'or step 24 by a padlock, bolt, or still other type of retainer. Moreover, if preferred, the rails 23 and interconnecting steps 24 can be completely removed by merely sliding this assembly entirely out of its engagement with the relatively stationary rails 13.

Many modifications are possible with the present ladder without departing from the spirit of the invention. For example, the sections 10 and 11 have been shown fixed at one end. However, it is understood that these sections may be pivotably hinged together, if desired. Also, as used herein, the word telescope and forms thereof are meant to mean generally one member having a generic, relatively sliding arrangement with respect to another member.

Although the foregoing describes several embodiments of the present invention, it is understood that the invention may be practiced in still other forms within the scope of the following claims.

I claim:

1. A ladder comprising two sections connected to one another at least through a substantially horizontally disposed platform adapted to define a standing area for a user of the ladder, each section having step means to enable that section to be ascended and descended, the step means of one section forming a unit telescopingly engaging its section and adapted for longitudinal movement thereof either to a position of inaccessibility while still forming a part of said ladder or optionally to a position entirely free of the ladder for independent use, retainer means mounted on the horizontally disposed platform, and retainer means on an appreciable number of the steps of said longitudinally moving section, each retainer means on a step cooperating with said retainer means on the platform, whereby the longitudinally movable section may be selectively retained at a plurality of its steps with respect to said platform when in a position of inaccessibility.

2. The ladder of claim 1 wherein said section having the telescopingly engaging unit includes relatively fixed side rails having U-shaped portions facing one another, and said unit includes opposed rails elfecting said sliding engagement with the U-shaped portions of the relatively fixed side rails and joined one to another by interconnect ing steps, said opposed rails being substantially I-shaped in cross section, the exposed ends of the I for at least one of the rails having flange beads partially encircling the adjacent edges of a U-shaped portion of a relatively fixed rail to enhance a free longitudinally guiding action therewith.

3. The ladder of claim 1 in combination with a wall member extending between said two sections, whereby said wall member may be selectively traversable or nontraversable dependent upon whether said movable step means is, respectively, in said usable or inaccessible positions.

References Cited UNITED STATES PATENTS 492,992 3/1893 Poetner 182-167 3,225,863 12/1965 Ludlow 182-230 3,288,248 11/ 1966 Gurian et al. 1'82l18 REINALDO P. MACHADO, Primary Examiner.

US. Cl. X.R.

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