US703836A - Extension-ladder. - Google Patents

Description

Patented July I, 1902.

c. H. scrmmaens EXTENSION LADDER.

(Application flied Mar. 22, 1902.)

(No Model.)

UNITED STATES ATENT QFFICE.

CHARLES H. SCHAMBERS, OF WARREN, PENNSYLVANIA.

EXTENSION-LADDER.

SPECIFICATION forming part of Letters Patent. No. 703,836, dated July 1, 1902.

. Application filed March 22, 1902. Serial No. 99,526. (No model.)

a citizen of the United States, residing at Warren, in the county of Warren and State of Pennsylvania, have invented a new and useful Extension-Ladder, of which the following is a specification.

The invention relates to improvements in extension-ladders.

The object of the present invention is to improve the construction of extension-ladders and to provide a simple and comparatively inexpensive one adapted to support a staging for carpenters, painters, and the like and capable of ready adjustment to arrange the staging at the desired elevation and to enable the supporting portion to extend beneath deep cornices and the like.

The invention consists in the construction and novel combination and arrangement of parts hereinafter fully described, illustrated in the accompanying drawings, and pointed out in the claims hereto appended.

In the drawings, Figure 1 is a perspective View of an extension-ladder constructed in accordance with this invention. Fig.2 is an enlarged sectional view of the upper portion of the extension-ladder, illustrating the manner of mounting the adjustable bracket. Fig. 3 is an enlarged detail view illustrating the construction of the ratchet mechanism. Fig. 4: is a detail sectional view of one side of the extension-ladder, illustratingthe con-' struction of the Windlass or shaft of the slidable section of the ladder. Fig. 5 is a detail view illustrating the manner of mounting the removable crank-handle.

Like numerals of reference designate corresponding parts in all the figures of the drawings.

1 and 2 designate sections of an extensionladder, and the section 1, which is designed to rest on the ground orother support, has its sides spread at the bottom to provide a broad base. The slidablesection2, which is arranged between the sides of the lower sec tion 1, is arranged on the rungs thereof, and it is secured on the same by upper and lower clamps 3 and 4:, located at the upper portion of the section 1 and composed each of a pair of arms 4. and 5 and a bar 6, hinged to one of the arms and detachably engaging the other. The bar 6 is provided at its ends with eyes 7 and 8, arranged betweeneyes 9 and 10 of the arms 1 and 5 and hinged to the arm 4 by a pintle 11 and detachably secured to the arm 5 by a removable pin 12, secured to the adjacent side ofthe section 1 by a short chain, as clearly shown in Fig. 1. The eyes of the arms-are arranged in pairs, and the arms extend outward beyond the outer edges of the side bars of the slidable section. The pins of the clamps are adapted to be readily removed to permit the arms 5 and the bars 6 to be separated for removing one of the ladder-sections from the other for enabling the said sections to be used independently of each other or for any other purpose.

The slidable section is raised and lowered by a rope or cable 13 and a Windlass or shaft 14. The rope or cable 13 is secured at one end to the bottom rung of the slidable section,and it extends upward therefrom to a pulley 15, mounted in a suitable block or support, which is suspended from the top rung of the lower ladder-section, and the said rope or cable extends downward from the said pulley 15 to the shaft 14, which is located a sufiicient distance above the lower end of the stationary .or bottom section of the ladder to enable it to be conveniently operated. The shaft is provided with a crank-handle 16, and it is locked by a pawl and ratchet, hereinafter described. By rotating the shaft the slidable section is raised and lowered, as will be readily understood. Each of the sections of the ladder is provided with a spur or projection at the lower end of each'of its side bars, and each spur or projection consists of a bolt or pin 17, mounted in suitable guides or eyes 18 and provided with an arm 19, arranged to engage projections 20 and 21. The bolt or pin is adapted to be rotated in the eyes or guides and when extended its arm is engaged beneath the lower projection 20. The upper projection is adaptedto be engaged by the arm to support the pin or projection in an elevated position. The pin or bolt is adapted to-be embedded in the ground or other support, and it will offectually prevent the ladder-sections from slipping. H

Mounted upon the slidable section of the ladder is a vertically-adjustable bracket 22,

composed of an approximately horizontal supporting portion, vertical slides Y23, and inclined braces 24. The slides, which extend longitudinally of the side bars of the upper or extension section of the ladder, are provided at their side edges with longitudinal flanges and are connected by crossed diagonal braces and by upper and lower transverse bars 26 and 27, the upper transverse bar being an gularly bent adjacent to its ends and oifset from the plane of the outer edges of the side bars of the extension-section for a purpose hereinafter described. The horizontal or approximately horizontal portion of the bracket is adapted to receive the staging or platform, and it is supported by the said braces 24, which are flanged. The sides of the horizontal supporting portion of the adjustable bracket are composed of bars or sections 28 and 29, provided at their upper edges with .teeth or serrations to prevent the staging or platform from slipping and having perforations arranged at intervals and adapted to receive fastening devices 30 and 31, whereby the bars or sections of the top or supporting portion of the bracket are secured in their adjusted position. The horizontal supporting portion of the bracket is adapted to be lengthened or shortened to enable it to extend beneath deep cornices or the like, and a roller 32 is journaled between the ends of the side bars 31 and is preferably covered by hard rubber or other suitable material and is adapted to engage the building or other structure. Instead of employing a smooth roller, as illustrated inFig. 1 of the accompanying drawings, a flanged bar or roller may be employed for enabling the latterto be supported against the uprights of a building before the same is completed. I

The side bars 30, which are rigid with the upright portions of the adjustable bracket, are also supported by crossed braces 33, secured to the bars 30 at the lower edges thereof. The roller 32 is removably mounted in the bearings of the bars 31 by means of keys or other suitable fastening devices to enable a flanged bar, as before described, to be used.

The adjustable bracket is supported by a rope or cable 34, passing over a pulley 35 of the extension-ladder section and secured at its ends to shafts or windlasses 36 and 37, mounted, respectively, on the extension-ladder section and on the bracket. The pulley 35 is mounted in a suitable block or casing,

which is suspended from the top rung of the extension-ladder section, as clearly shown in Fig. 1. The lower shaft 36, which is journaled in suitable bearings of the extensionsection of the ladder, is constructed substantially the same as the shaft or Windlass 14, with the exception that the crank-handle 39 is removable.

The crank-handle 39 is provided with a threaded stem 39, arranged in a threaded socket 40 of the shaft 36 and adapted to permit the crank-handle 39 to be removed when the latter is rotated backwardly to unscrew the threaded stem; but when the crank-handle is rotated forwardly it will be firmly held on the shaft and will carry the same with it. The crank-handle is adapted to be removed to permit the shaft 36 to pass the clamps 3 and 4 to raise the extension-section to the limit v of its upward movement, and such upward movement is limited by the spurs or projectionsformed by the bolts or pins 17. When the movable or-extensiou section is raised to the limit of its movement, the spurs or projections engage the lower clamp 4 and prevent a further upward movement of the said section, so that-there is no liability of acci- The suptions of the adjustable bracket, is composed of approximately L-shaped sides connected at their lower ends by a rung 43 and pivoted at their upper ends to the upright portions of the bracket. The lower transverse bar 27 has its ends bent outward to form arms 44, which are provided at their outer sides with projec tions 45, arranged to be engaged by the pivoted support, whereby the rung 43 will be olfset from the ladder-section 2. The adjustable bracket is also provided at the inner face of the ladder-section 2 with upper and lower transverse bars 26 and 27, and the shaft or windlass of the adj ustable bracket is adapted to be readily rotated to enable the bracket to be lowered by a person standing on the rung 43-01: the support. The upper transverse bar 26 is ofiset from the ladder-section to permit the hand of a person standing upon the support to clear the rungs of the ladder as the adjustable bracket is lowered. The offset rung 43 and the side bars of the support 42 are also adapted to clear the upper and lower clamps in lowering the bracket to the top of the lower laddersection. The lower ladder section is shorter than the extension-ladder section to enable the latter to be lowered to and rest upon the ground, and after this has been done the clamps may be unfas'tened to release the lower ladder-section to permit the same to drop back against the building or IIOA wardly the pawl or dog is locked out of engagement with the ratchet-wheel by the dog 47, as clearly shown in dotted lines in Fig. 3 of the drawings. The dog 47 is preferably pivoted between its ends and its movement is limited by a stop 48, and it is provided with a suitable grip or handle. If desired, however, the locking-dog may be pivoted at one end or consist of a single arm instead of a lever, as shown.

The ladder-sections are adapted to be used independently of each other when desired, and they are capable of ready adjustment to arrange the adjustable bracket at any height, and the bracket is also capable of adjustment both to raise and lower it and to vary the length of its horizontal or supporting portion to position the parts properly with relation to the building or other structure and to enable them to support a platform or staging of the desired width. The platform or staging is supported by a pair of extension-ladders of the form illustrated in the accompanying drawings, and they may be connected by a rope anchored to the ground or otherwise secured to prevent the staging or platform from slewing or moving the ladders laterally.

What I claim is 1. In a device of the class described, the combination of the ladder-sections 1 and 2, the section 2 being capable of movement longitudinally of the section 1, the arms mounted on the section 1 and extending beyond the other section and provided With eyes, the lockingbars provided with eyes at their ends, the eyes at one side of the ladder being hinged to the eyes of the adjacent arms, and removable fastening devices engaging the eyes of the locking-bars and the arms at the other side of the ladder, substantially as described.

2. In a device of the class described, the combination of a ladder-section, an adjustable bracket slidably mounted on the laddersection and projecting therefrom at one side thereof, a support depending from the bracket at the opposite side of the ladder, and hoisting mechanism connected with the bracket and with the ladder-section and having oper-v ating mechanism mounted on the bracket and located within reach from the support, substantially as described.

3. In a'device of the class described, the

arms having projections, a pivoted support composed of approximately L-shaped sides supported by the projections, and a rung connecting the sides, and atransverse bar located above the support and forming a grip or handle, substantially as described.

5. In a device of the class described, the combination of a ladder-section, a verticallymovable support mounted on the ladder-section and provided with an adjustable support ing portion having a roller for engaging a building, hoisting mechanism connected with the ladder-section and with the bracket and having shafts or windlasses mounted on both of such parts, and a support carried by the bracket, substantially as described.

6. In a device of the class described, the combination of the ladder-sections 1 and 2 detachably connected, an adjustable bracket mounted on the ladder-section 2, a lower hoisting mechanism connecting the laddersections, an upper hoisting mechanism connecting the bracket with the ladder-section 2 and provided at each end with means for operating it, and a support carried by the bracket, substantially as described.

In testimony that I claim the foregoing as my own I have hereto affixed my signature in the presence of two witnesses.

CHARLES H. SOHAMBERS.

WVitnesses:

D. M. HOWARD, R. V. STONE.

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