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Publication numberUS838831 A
Publication typeGrant
Publication dateDec 18, 1906
Filing dateJan 4, 1906
Priority dateJan 4, 1906
Publication numberUS 838831 A, US 838831A, US-A-838831, US838831 A, US838831A
InventorsFrank Wilson
Original AssigneeDaniel W Church, Frank Wilson
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Extension step-ladder.
US 838831 A
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Description  (OCR text may contain errors)

N0- 838,831.` PTENTED DEG. 18, 1906.


Arrmoumx FILED ulm, 190e.

,JP/m# may@ A o. 838,831. PATBNTED DEG. 18, 1906.






Specification of Letters Patent.


4 Patented Dec. 1.8, 198.

Application filed January 4, 1906.` Serial No. 294.637.

T0 all whom it muy con-:ern:

Be it known that I, Fna'xit WiLsox, a citizen of the Ifnited States, residing at Pocatelle, in the county of Bannock and State of Idaho, have invented `a new and useful Extension Step-Ladder, of which the following is a specification.

This invention relates to step-ladders, and has for its object to provide a comparatively simple and inexpensive device of this character capable of being extended to any desired height. and which when in lowered or normal position will have the appearance of an ordinary step-ladder.

A further object ol' the, invention is to provide a step-ladder comprising a plurality of extensible sections, one of which is provided with spacedauxiliary steps movable laterally to operative position when the adjacent section is extended. 4

A further object is to provide the extensible sections with interfitting parts and means for locking said sections in adjusted position.

A still further object of the invention is to generally improve this class of devices so as to increase their utility, durability, and etiiciency.

With these and other objects in view the4 invention consists in the construction and novel combination and arrangement of parts hereinafter fully described and illustrated inthe acconipanying.,r drawings, it beingunderstood that various changes in form, .proportions, and minor details of construction may be resorted to within the scope of the appended claims.

In the acccompanying drawings, forming a part of this specification, Figure 1 is a side elevation of au extensible step-ladder constructed in accordance with my invention. Fig. 2 is a. front elevation of the same. Fig. 3 is a longitudinal sectional view. Fig. 4 is a similar view showing the ladder in extended position. Fig. 5 is a transverse sectional view showing the ladder folded. Fig. 6 is a top plan view of the locking-yoke.

Similar numerals of reference indicate corresponding parts in all of the figures of the drawings.

The ladder comprises relatively stationary and movable sections, the lower one of which is formed of parallel bars 5 and 6, spaced ter being provided with a t epending extenin any suatable` manner to the head or cap piece 11, the lat` sion 42, spaced from the adjacent bar 8 by a Ablock 13 similar in construction to the block 10.

Secured to the extensible upper section of the ladder are a plurality of spaced rigid steps 14, the opposite ends of which are provided with spaced tenons 15, which engage suitable inortises 16, formed in the bars'8 Yand'9.

The parallel bars comprising the upper and lower sections of the ladder are each provided with a tongue 17, adapted to engage a. Correspondingly-shaped groove 18, formed in the adjacent bar, whereby the bars are guided in their upward movement and retained in alinement with each other.

Secured to the lower or free ends of the bars 8 and 9 is a bracket 19, the angular arms of which are fastened to said bars and serve to maintain the same in spaced relation, there beinga similar bracket 20 secured to the upper or free ends of the bars 5 and 6, as shown.

Secured to the bar 5 at the lower end thereof is a block 21, the upper end of which is inclined or beveled to corres ond tothe inclination of the block 7, said b ock serving to support the lower edge of the bars S and 9 when the extensible sect-ion is in lowered or normal position, there bein(r a bolt 22 extending transversely througlli the blocks 7 and 21 and piercing the bars 5 and 6 for seciu'ing the several parts together.

Fastened at spaced intervals to the bars 5 are laterally-extending lugs or su )portingbrackets 23, ada ted to receive and suport the auxiliary fol( ing steps 24 when the atter are swung downwardly to operative position, as best shown in Fig. 4 of the drawings.

The auxiliary ste s 24 are provided with oppositely-dispose reinforcing -plates 25, having laterally-extended lugs 26, which engage openings in the bars 6 and are pivotally supported on said bars by suitable nuts 27. Connecting the bars 6 of the relatively stationary lower section are diagonal braces 28,

` which serve to reinforce and strengthen the ladder anda-lso serve to support the movable steps 24 in vertical or inoperative posit-ion.

The rigid steps 14 are provided with oppositely-disposed openings or recesses 29, disposed in alineinent with the supporting lugs or brackets '23, thereby to permit the upper section to be adjusted vertically without interfering with said brackets.

Pivotedto the extension 12 of the head 11, as indicated at 30, is a pro i or support consisting of a plurality of slit ing bars and 31, connected together by guiding loops or bands 32, there beingr a plurality of spaced notches or recesses 33 formed in the exposed or outer face of the bai' 31 for the reception of the looped ends 34 of the locking-yoke 35. The locking-yoke 35 is pivotally mounted for swinging movement on the bar 30', wheieby when the upper bar 31 of the rop is adjusted vertical y to the desired ieight the yoke 35 may be swung downwardly in engagement with the adjacent notch 33, and thus lock the rop in adjusted position.

Extending ongitudinally of the bar 31 is a wear-plate 3G, provided with spaced delpres- 'sions which engage the .interior wals or `notches 33, said plate being extended laterally over the notches 33, as indicated at 37 thereby to prevent accidental displacement of the loo s 34 of the locking-yoke.

Secure to the base of the relatively stationary section are laterally-extending feet orbrackets 3S, which bear against the floor or other suitable support and serve to prevent tilting movement of the ladder.

In o eration when it is desired to adjust the lat der vertically the locking-yoke 35 is released from the notches in the prop-bar 31 and the upper extensible section of the ladder adjusted to the desired height. The movable steps 24 are then swung downwardly in engagement with the supporting lugs or brackets 23, after whichthe upper extensible section is lowered until the adjacent rigid step engages the upper movable ste-p and the yoke 'Z5 swung laterally into engagement with the adjacent locking-notches, tlius forming a support for the extensible section and locking the saine in adjusted position.

In order to lower the extensible section, the yoke 35 is released, after which the movable steps 24 are swung upwardly and laterally into engagement with the diagonal braces 28, thus permitting the upper section to be lowered until the ends of the bars 8 and 9 bear against the inclined faces of the blocks and Z1 and in which position the parallel bars of the upper and lower sections of the ladder will be disposed in horizontal alinenient, as best shown in Fig. 1 of the drawings.

From the foregoing description it is thought that the construction. and operation of the device will be readily understood by those skilled in the art and further description thereof is deemed unnecessary.

Having thus described the invention, what is claimed is 1. A ladder comprising a plurality of relatively stationary and movable sections having in tei-fitting parts one of said sections being provided with rigid steps having oppositely-dis osed recesses formed therein, supporting-brackets secured to the stationary section and movable through the recesses in the extensible section when the latter is adjusted, and movable steps pivotally mounted on the stationary section and adapted to engage said brackets.

l2. A ladder comprising a lurality of relatively stationary and inova le sections each consisting of parallel sliding bars spaced apart by reinforcing-brackets and provided with intertitting parts, a plurality of spaced rigid steps secured to the extensible section, movable steps pivotally mounted on the stationary sections, supporting-brackets securedv to said stationary section and adapted to receive the movable steps when the latter are moved to operative position, diagonal braces arranged at the rear of the movable steps for supporting the latter in inoperative position, and spaced blocks secured to the stationary section and adapted to support the extensible section when the latter is moved to closed position. e

FRANK WILSON. Witnesses:


Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US2538501 *May 6, 1946Jan 16, 1951Ambrose BianchiLadder
US4240522 *Dec 11, 1978Dec 23, 1980R. D. Werner Co., Inc.Extension trestle ladder
US4796727 *Feb 1, 1988Jan 10, 1989Eaton Earl VFolding step ladder
Cooperative ClassificationE06C1/387