US1555344A - Convertible extension and step ladder - Google Patents

Description

Sept. 29, 1925.

J. L. WHITNEY CONVERTIBLE EXTENSION AND STEP LADDER 2 Sheets-Sheet 1 I Filed Dec. 6, 1924 Sept. 29,v 1925.-

J.' L. WHITNEY CONVERTIBLE EXTENSION AND STEP LADDER Filed Dec. 6, 1924 2 Sheets-Sheet 2 Zlwoentoz Patented Sept. 29, 1925.

UNITED STATES r 1,555,344 PATENT OFFICE.

JOHN L. WHITNEY, OF SAN PEDRO, CALIFORNIA, ASSIGNOR OF ONE-THIRD TO WIL- I HELMINA WETMORE AND OF ONE-THIRD TO FRANK L. E. WETMORE, BOTH OF SAN PEDRO, CALIFORNIA.

CONVERTIBLE EXTENSION AND STEP LADDER.

Application filed December 6, 1924. Serial No. 754,371.

To all whom it may concern:

Be it known that I, JoHN L. WHITNEY, a citizen of the United States, residing at San Pedro, in the county of Los Angeles and State of California, have invented certain new and useful Improvements in Convertible Extension and Step Ladders, of which the following is a specification, reference being had to the accompanying drawmgs.

This invention relates to ladders, and particularly to step-ladders.

One of the objects of the invention is to provide a ladder which is convertiblefrom a long ladder such as adapted tobe disposed against the side of a house to a relatively short step-ladder having legs.

A further object of this invention is to provide a ladder of this character formed in a plurality of sections, each of these sections being adapted to be disposed one upon th other and operatively engaged with each other to thereby form a long ladder or to be disposed so that one of the sections constitutes the brace or support for the other section after the manner of the legs of the step-ladder.

A still further object is to provide a device of this character wherein the section which constitutes the legs of the step-ladder is locked to the rung section when the sections are arranged to form a step-ladder.

Other objects have to do with the details of construction and arrangement of parts as will appear more fully hereinafter.

My invention is illustrated in the accompanying drawings, wherein Figure 1 is a side elevation of an extension ladder constructed in accordance with my invention;

Figure 2 is a front elevation of the same;

Figur 3 is a perspective view of one end of one of the ladder sections;

Figure 4 is a fragmentary side elevation of two of the ladder sections put together parallel to each other; 4

Figure 5 is a side elevation showing the two ladder sections in Figure 4. turned into angular relation to each other;

Figure 6 is a front elevation of the arrangementshown in Figure 5.

Referring to these drawings, it will be seen that my improved ladder consists of two sections A and B, each of these sections comprising the longitudinally extending side rails 10 and the rungs 11- The rails and rungs may be connected in any suitable manner and I do not wish to be limited to this. The rung 12 at one end of each section is longer than the rungs 11 so that it projects beyond the side rails 10. All of these rungs are held to the side rails in any suitable manner, and preferably bolts 13 are disposed through the side rails adjacent the ends thereof so as to prevent these side rails from splitting. The side rails at their extremities are longitudinally slotted, as at 14, the inner end of each slot being rounded so that the slots of the side rails of one section will accommodate the rung of the other section and so that at the same time the side rails of the first section will have its slots engaged with th rung 12 of the next adjacent section in the main ner shown in Figure 2. It will be seen in this figure that the upper end of section B is narrower than the lower end of section A so as to fit inside of the section A,

So far I have described a ladder which is made of sections which may be operatively engaged with each other to double the length of the ladder or, in fact, to increase its length more than double by having three or more sections adjusted in this manner, and I will now describe the manner in which the two sections of the ladder may be converted into a step-ladder. Mounted upon one rail of the section A adjacent the upper end thereof is an outwardly bowed meta] strap 15 which is held to the rail by means of bolts 16 or by any other suitable means. The section B is also provided witlr the metal strip 15 held on by bolts 16, the metal strip being outwardly bowed at its middle. Under these circumstances, when the section A is disposed as shown in Figure 6 with the rails of section A laterally off-set with relation to the rails of section B, then it will be obvious that one end of the rung 12 of section A will be disposed through the bowed strap 15 of section B, while one end of the rung 12 of section B will be disposed through the bowed strap 15 of section A and that the two sections will thus be operatively pivoted or hingedto each other.

In order to lock the two sections together and prevent any lateral movement of detachment, the rung 12 of section A is provided with a radially extending pin 17, as is the rung 12 of srction B, so that when the section B is turned into angular relation to the section A, these pins or lugs will lock against the side edges of the strip and will prevent any lateral movement of the two sections so long as the two sections are in angular relation. At the same time, when the sections are turned into parallel relation by a lateral movement, the two sections may be readily separated. 7

It will also be seen from Figure 5 that when the two sections are turned into angular relation to form the step-ladder that the rails of the section A will bear against the rung 12 of section B and the rails of section B in turn will. bear against the rung 12 of section A and that thus the possible angular divergence of the two sections is limited.

Thus I have provided a ladder, one section of which may be used without any legs or supports, two sections of which may be used. without any legs or supports to form an extension ladder, or in which one section may be used as a support for the other section, and when the two sections are used in the form of a step-ladder with one section acting the legs of the ladder and the other section as the main body of the ladder, these two sections are locked together.

I do not wish to be limited to the detailed construction of the ladder, as it is obvious that this might be changed in many ways without departing from the spirit of the invention as defined in the appended claims.

I claim l. A ladder composed of two sections, the sections being adapted to be fitted together to constitute an extension ladder, each of these sections having upon one edge face an outwardly bowed bracket, each of these sections having adjacent one end a rung projecting laterally beyond the rail of the section at one end of the rung and adapted to engage in the bracket of the other section whereby said sectionsare sup ported for swinging movement and may be placed in angular relation to each other.

2. A convertible ladder comprising two sections so formed that they may be disposed in conjunction with each other to provide an extension ladder, each section comprising parallel rails and rungs, each section having upon one edge face of one rail an outwardly bowed bracket and each section havat one end a rung projecting laterally beyond a rail of the section and adapted to be inserted in the bracket of the section, the like rung of the other section constituting a stop limiting the angular movement of the sections.

3. A ladder composed of two sections, the

disposed across the bracket and in engagement over the outer edge thereof when the sections are in angular relation to each other to thereby lock the brackets from lateral movement.

In testimony whereof I hereunto ailix.

my signature.

JOHN L. 'WHITNEY

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