US524195A - Extension step-ladder - Google Patents

Description

- (Hommell.)

R. vDIINGEL,

EXTENSION STEP LADDER.

. No.y 524,195. Patented Aug. 7; 1894.-

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PATENT OFFICE.

RUDOLPH DENGEIJ, OE BROOKLYN, NEW YORK.

EXTENSION STEP- LADDER.

SPEGIFICATION forming part of Letters Patent No. 524,195, dated Augusta, 1894.

Application iledApril 6,1894. Serial No. 506.540. (No model.)

s To all whom it may concern.-

\ reference being had Be it known that I, RUDOLPH DENGEL, a citizen of the United States, residing at Brook'- lyn, in the county of Kings and State of New York, have invented certain new and useful Improvements in Extension Step -Ladders;

and I do declare the following to vbe a full,`

. ladders and it is designed especially for the use of electric wiremen and othersin positions impracticable for* the ordinary step-ladl der; for example, on stairways or upon sloping. zo

galleries in theaters. It is further adapted to be turned into and used as a straight ladder. y

The invention consists essentially of three main co-operating sections, two of which are pivoted together at the ends and the third movesup and down between the sides of the second section as more fully hereinafter de- Y scribed.A

the invention extended Y'which A is provided with Mary construction except the topmost step,

In the accompanying drawings like characters represent the same parts in the dierent views.

Figure l is anoutline perspective showing for use upon surfaces in dierent planes, and Fig. 2 presents the device when turned into a straight ladder.

' A, B and C are the three main sections, of

steps of the customwhich is very much heavier and stronger than the others. The side boards of section A are i widened from a'point near the top upward and l 1 furnish bearings in the added width, somewhat below the top ofsaid side boards, for the stout pivot roll, l. With its upper ends between the widened parts of the side boards of sections A, and upon the roll, 1, as a pivot there swings the section, B, having longitudinal slots extending through the greater'part y of thelength of the side boards of this section.

In the direction of their width said side boards are pierced with holes through whichthe eye bolts or pins, 4, pass across the said slots for the purpose more fully explained in the fol lowing paragraphs. Section B possesses no steps and to preserve its rigidity two stiff cross pieces, 5, connect the slotted side boards at the extreme lower ends; said cross pieces serving the additional purpose of guides for the edges of the side boards of section, C. This third section,C, is less in width than and 6o movable between the slotted sides of said sec tion, B, and is provided withsteps so placed, with relation to 'the side boards, that when the invention is turned to form a straight ladder all the steps of A and C willfall in practically parallel planes. Midway and lengthwise of the step connectingthe extreme upper ends of the side boards of section C, and securely fastened thereto, is the thick cross bar,

3, exceeding in length the width of section C 7o by enough to pass ywell, through the slots in the side'boards of B.

-rGonsidering the mode of operation, section i C beingentirely inclosed withinvB, the ladder is adapted for a level surface and theangle between A and Bis governedand maintained `by slotted straps, 6, one upon each side of the ladder, pivotally attached to B and fastened by simple crossnuts upon Aas shown at 9 in Fig'. 1. It being desired to place the ladder 8o upon a stairway, section C is! dropped until such length is attained as will allow for the difference in levels of the stairs, whenthe eye-bolts, 4, are passed through the holes in the slotted sides of B above the cross bar, 3, 85 limiting the return of C within said section B. The cross pieces, 5, in connection with and aided by the bearing of the ends of the cross bar, 3, against the sides of the hold the two sections B and C in proper align` 9o ment. It being desired to turn the invention into a straight ladder, sections B and C are closed one Within the other, or partly so, and both are swung upward upon the pivot roll, l, until their edges meet the heavy step, 7, which is fashioned of such material and strength as to easily resist the pressure of said edges against it. My construction is such that the slotted strap, 6, again becomes available and locks the ladder in its straight form by means roo of other cross nuts upon A at 8.

All the parts of my step ladder are intentionally of the simplest description and designed to be made of such strength as to with slots, 2,

stand successfully the rough usuage to which such articles are constantly subjected.

I am aware that step-ladders have been made adapted to be used upon stairways and inclines, and to be turned into straightladders and with such constructions in view- Having thus described my invention, what I claim, and desire t0 Secure by Letters Patent, is

l. In an extension step ladder consisting of three main sections, the section, A, provided with steps and top-widened side boards, the section, B, pivoted t0 A near the top and having side boards slotted lengthwise for the admission and guidance of the cross-bar, 3, attached to the uppermost step of section, C, said section, C, movable up and down between the slotted sides of B, said motion being limited by pins, 4, transversely'piercing the side boards of B, the whole so constructed and arranged as tobe used upon levels or inclines and adapted to be turned into a straight ladder capable of variations'in length substantially as described. l

2. In an extension step-ladder the combination of the section, B, having slotted side boards pierced with holes for the insertion of the eye-bolts and provided With the stift cross pieces, 5, as shown and described, with the section, C, moving between the slotted sides olf B said section C having securely fastened upon its topmost step a heavy cross bar, 3, the ends of which travel in the slotted sides of B and are governed by said eye-bolts or pins as hereinbefore described for the purposes set forth. I

3. In an extension step ladder consisting of three main sections, the combination of the section, A, having side boards widened at and near the top and provided with steps, the topmost of said steps, '7, being thicker and stronger than the rest and less in width than the side boards at that point; the section, B, pivotally attached to A at 1, and possessing side boards with lengthwise slots, 2, transverse oritices for the insertion of pins, 4, the cross-pieces, 5, the slotted braces, G, adapted to be fastened by the cross-nuts at 8 and 9 upon A; the third section, C, movable between the sides of B and provided with steps as described, the cross-bar, 3, upon the uppermost of said steps, extendinginto and mov `able along slots, 2, ot section B, said motion limited by said pins, 4, the whole constructed and arranged to be used upon levels or inclines and as a straight ladder the length ot' which may be varied substantially as specified.

4. In an extension step-ladder consisting of three main sections in combination, the section A provided with steps the topmost step being of extraordinary thickness and strength, and having side boards widened near 'the top and pivotally attached to the scction, B, of the construction shown, and the section, C, provided with steps and the heavy cross bar, 3, and adapted to move between and within the slotted sides ot' section B; the whole constructed and arranged to be used upon level surfaces, stairways or inclines and turned into a straight ladder substantially as shown and described. y

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

' RUDOLPH DENGEL. Witnesses:A

GEO. VAN BENscHo'rEn, Louis DUDLEY MARTENS.

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