US1070908A - Convertible ladder. - Google Patents

Description

H. MUTE.

CONVERTIBLE LADDER.

APPLIOATION FILED MAY 4, 1912.

1,070,908, Patented Aug. 19, 1913.

2 SHEETS-SHEET 1.

.Zizzrezzzar H. MOTE.

CONVERTIBLE LADDER.

APPLIOATION FILED MAY 4, 1912 1,070,908, Patented Aug. 19, 1913.

2 SHEETS-SHEET 2.

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HORACE MOTE, OF CLEVELAND, OHIO, ASSIGNOR TO THE STEELBACK LADDER COMPANY, OF CLEVELAND, OHIO, A CORPORATION OF OHIO.

CONVERTIBLE LADDER.

Application filed May 4, 1912.

-T 0 all whom it may concern Be it known that I, HORACE MOTE, a subject of the King of England, residing at Cleveland, in the county of Cuyahoga and State of Ohio, have invented certain new and useful Improvements in Convertible Ladders, of which the following is a speci fication.

My invention relates to improvements in convertible ladders, and has for its object the construction of ladder-members which may be united in interchangeable relation, for the purpose of forming a step ladder, an extension ladder or a scaffold or tower ladder. These are formed of two types of ladder-members, one of which is a step-carrying section, and the other a rung-carrying section, which may respectively be united to form the difierent classes of ladders named. My said improvement contemplates the construction of such ladder-members provided with uniting brackets having stationary retaining parts thereon, adapted to secure the ladder-members in different angular and extended relation to each other.

The embodiment of my invention may be briefly described as consisting of a step ladder section, which may be of ordinary construction, but equipped adjacent to its upper end, with two laterally positioned brackets, respectively secured to the side pieces of the ladder and the top step; each of said brackets being equipped with two hooks positioned in different planes. Associated therewith, is a second ladder-member of substantially the same length as the step ladder section, but provided with rungs and side pieces mitered at one end; any of said rungs being adapted for insertion within the hooks of the bracket, in order to convert the ladder to the forms mentioned above.

Further details of my improvement may be more readily explained and understood by making reference to the accompanying drawings, wherein Figure 1. is a fragmentary view in vertical sections, showing the upper portion of a step ladder and the bracket-member embodying my invention. Fig. 2. is a view in side elevation of said bracket-member. Fig. 3. is a fragmentary view in vertical section, of an extension ladder, embodying my invention. Fig. 4. is a perspective view of the ladders combined to form a tower-ladder.

Specification of Letters Patent.

Patented Aug. 19, 1913.

Serial No. 695,236.

The figures have been drawn upon different scales to bring out the various features of improvement in condensed form.

I have employed the same character of reference to designate similar parts throughout the several figures of the drawings.

Preferably the side pieces a of the step ladder section are somewhat spread at the base; being united by the transverse steps b and the top step 1). Between the top step b and the next step b, the two brackets, a, formed of malleable iron, are secured respectively to the side pieces a and the under and upper faces of said steps, by means of wood screws. These brackets 0 are symmetrical and are cast from malleable iron in right and left patterns, to brace the upper portion of the step ladder, and accommodate the second ladder-member. Referring specifically to the figures of the drawing, showing one of said brackets, it is seen that it comprises an upright d provided with screw holes for securing it to the side piece; a slotted head 6 adapted to engage the top step b; a slotted foot f, adapted to engage the second step b, and two hooks g 71, respectively positioned in dilferenthorizontal and vertical planes for accommodating the different rungs of the ladder-member. The second ladder-member comprises two arallel side pieces i, mitered at their en s i and united by the usual rungs 2'; each of said rungs adapted to fit within the hooks g h of the bracket. From these simple ladder-members, or duplicates thereof, in case the scaffold, or tower ladder is desired, the three above mentioned types of ladder may be quickly and easily formed without the aid of tools.

As shown in Fig. 1, the step ladder section and the rung ladder-member may be united by inserting the upper rung i" of the latter within the hooks g. The laddermembers are accordingly disposed at an angle, with the mitered ends 11 of the side pieces i bearing against the rear faces of the side pieces a, in order to form a strong and rigid step ladder. Again, by placing the rung ladder-members parallel, with any of the rungs 1'" supported by the hooks h, an extension ladder of variable length is provided as shown in Fig. 3. Finally, by uniting two rung ladder-members by means of spring clamps la embracing their side pieces 71' above and below, and supporting their corresponding rungs 2'" respectively from the hooks g of two opposed step ladder sec tions, as shown in Fig. 4, a tower ladder of variable height may be constructed, either for use alone, or in association with another similar ladder, for supporting a scaffold plank.

For convenience of designation, I have indicated the step ladder sections upon drawings, by the reference character Z, and coacting rung ladder-members, by the reference character m.

My improved means for convertibly uniting the ladder sections, comprises essentially, two stationarily secured, symmetrical castings or forgings positioned adjacent to the upper end of a ladder section, at either side thereof; each affording two hooks, or recessed portions adapted to respectively embrace a ladder rung in two different vertical and horizontal planes, substantially as shown. The hooks 9, it will be observed, support the rung ladder member against movement, either vertically or away from the step-ladder section, when engaging a rung of the former. In addition, each bracket-member preferably is provided with a head and base portion respectively attached by means of slot-engaging screws, to the two upper steps of the ladder-section, whereby a much more rigid structure is attained. Said bracket, moreover, preferably affords an offset shoulder at which is adapted to engage the rear of the side piece and a recess f adjacent to the lower hook 72 which bears against the step b, as best shown in Figs. 1 and 2, thus insuring a firm rigid support for the upper ladder-member of an extension ladder.

It will be apparent that the rungs of the extension ladder, will register with the steps of the step ladder, which is the pre ferred arrangement, rat-her than to make an irregularly spaced connection between the two ladder-members.

Having now described apparatus embodying my invention and the principal utility thereof, I claim as new, and desire to secure by Letters Patent, the following A combination ladder, comprising a stepladder section and a rung ladder-member of approximately equal lengths, and two brackets stationarily secured to the step next adjacent to the top of said step-section and close to the side pieces thereof, each of said brackets being provided with a rung-supporting recess in alinement with the step, and adjacent thereto, and with a hook intermediate of the two upper steps and so distanced from the rear face of the step-section as to receive a rung of the rung ladder-member standing vertically, while the step-section is at the usual inclination with the vertical; said hook being formed to support the rung against movement either vertically or away from the step-section, substantially as set forth.

In testimony whereof I do now affix my signature in the presence of two witnesses.

HORACE MOTE.

WVitncsses:

C. V. PUTNAM, ALBERT LYNN LAWRENCE.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C.

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