US341284A - Folding ladder - Google Patents

Description

(No Model.)

D. P. SHARP.

FOLDING LADDER.

No. 341,284. Patented May 4, 1886.

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NlTEI) STATES PATENT Fries.

DENNIS P. SHARP, OF ITHACA, NEYV YORK.

FOLDING LADDER.

SPECIFICATION forming part of Letters Patent No. 341,284, dated May 4:, 1886.

I Application filed December 14. 1885. Serial No. 186,608. (No model.)

To all whom, it may concern.-

Be it known that I, DENNIS I. SHARP, of Ithaca, in the county of Tompkins, in the State of New York, have invented new and useful Improvements in Folding Ladders, of which the following, taken in connection with the accompanying drawings, is a full, clear, and exact description.

This invention consists in a novel organization of a foldingladder, which has double rungs forming wide steps similar to those of an ordinary step-ladd er, and which ladder is also extensible in length, and thoroughly bracedlaterally,and securely supported about the hinge by which the ladder-sections are connected.

In the accompanying drawings, Figure I is a side elevation of my improved folding ladder shown in three different positions. Fig. II isa front view of the same. Fig. III is a transverse section on line 00 m, Fig. II. Fig. IV is alongitudinal section of that portion of the ladder at which the side rails of theladder are hinged to each other, and Fig. V is a front view of the ladder in its folded condition.

Similar letters of reference indicate corresponding parts.

A A and A A represent four rails arranged in pairs, constituting the two sides of thelower or main and upper or supplemental sections of the folding ladder. The rails of the supplemental section are hinged at their lower ends to the adjacent upper ends of the rails of the main section so as to swing in a plane I at right angles to that of the ladder, and

allow the ladder-sections to fold back to back by means of plates to a bolted onto the exterior of the adjacent end portions of the side rails A A. These plates are formed with inward offsetsb b, which serve as bearings, against which the ends of the side rails abut, and thus greatly relieve the attaching-bolts of the plates from the strain exerted endwise on the ladder. The plates terminate with deflections c c toward each other, and their deflected end portions are perforated for the reception of a bolt or rivet, which passes through the two end portions placed one against and back of the other, said belt or rivet constituting the pivot of the ladder-sections.

In order to limit the aforesaid swinging movement of the ladder-sections,I provide the plates a a with lugs (Z d, which project over the edges of the plates a a, the ends of which latter are made semicircular concentric with the pivot, so as to allow the lugs to freely pass around the edge of the ends of the plates a a while swinging the supplemental ladder-see tion from its folded position up to its distended position, as represented in fulllines in Fig. I of the drawings, and when in thislatterpositiou the lugs d d encounter the edges of thedeilected portions of the plates (1. a, and are thereby arrested in their movement. If the ladder is then inclined, and placed to rest with the free end of the supplemental ladderscction against a fixed support, the hinged portion of the ladder is rendered self-supporting by the bearing of the lugs (Z (l on the edges of the de fleeted end portions of the plates (t a, as before described.

ff represent metal brackets secured to the inner sides of the rails A A at corresponding distances from the hinged ends of said rails, and equidistantly apart, and in said brackets are pivoted the ru ngs r 1*, which are of alength to allow each to fall back of the adjacent rung and lie closely against the inner sides of the side rails when the ladder is folded laterally, as represented in Fig. V of the drawings. The corresponding disposition of the rungs of the ladder-sections allows the latter, after they are folded back to back,to be folded laterally conjointly.

Inasmuch as my invention is designed for use as a step-ladder as well as an ordinaryladder, I make the side rails A A of sufficiently increased width to pivot thereon double rungs arranged one back of the other, and with the rear rung sufficiently nearer the pivoted end of the rails A A to bring the two rungs as near as possible within ahorizontal plane when the ladder is set up for use as an ordinary stepladder; the double rungs forming the wide steps desired in a step-ladder.

B denotes a lateral brace,which is extended diagonally across the ladder, and pivoted at its ends on the sides of two of the brackets f' f by the pivoting-pins of the rungs passing through the ends of said brace.

The central or intermediate portion of the brace B is provided with a knuckle-joint, c, which has its shoulder or step on the top and sufficiently back of the joint to allow the central portion of the brace to slightly sag or become depressed, and thus partially lock the brace in its distended position.

In folding the ladder the central portion of the brace has to be raised out of its locked position,'after which it will readily fold compactly between the side rails simultaneously with the folding of the rungs.

Having described my invention, what I claim is 1. A ladder having rungs arranged in pairs, and the rungs of each pair arranged one back of the other and nearer the upper end of the ladder, substantially as set forth.

2. The combination, with two ladder-sections, of the plates a a, formed with the bearings b b for the ends of the side rails, and terminating in the deflections c, and pivoted to each other thereat, and the plates a a, provided with the lugs d d, to engage the edges of the other plates, and thereby arrest the swinging movement of the plates a, substantially as described and shown.

3. A folding ladder having pivoted double rungsarranged one back of. the other, and the rear rung pivoted nearer the upper end of the ladder than the front rung, substantially as described and shown, for the purpose set forth.

4. In combination with the side rails A A,and rungs r r pivoted thereon, the brace 13, pivoted at opposite ends to the ladder, and having 0 1 its intermediate portion depressed and provided with the knuckle-joint a, substantially as described and shown.

5. In combination with the side rails A A, brackets f f, and rungs '1 r, pivoted on said brackets, the articulated brace B, pivoted at each end on one of the brackets, and by the pivoting-pin of the rung, substantially as described and shown.

In testimony whercofI have hereunto signed my name and affixed my seal, in the presence of two attesting witnesses, at Syracuse, in the county of Onondaga, in the State of New York, this 10th day of November, 1885.

DENNIS P. SHARP. [L. s]

Vitnesses:

FREDERICK H. GIBBS, E. O. CANNON.

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