US1377543A - Ladder-foot extension - Google Patents

Description

o. A, ALM. LADDER FOOT'EXTENSION. APPLICATION FILED MAYS,1920.

1,37*?,5/3D Patented L0, i921.

/4/5 #Trae/VE? resort to tools.

UNIT STATES Mer OSCAR ALFRED ALM, OF BINFORD, NORTH DAKOTA.

LADDER-FOOT EXTENSION.

Application led. May 5,

T0 all /wzom t may concern;

Be it known that l, OSCAR A. ALM, a citizen of the United lStates, residing at Binford, in the county of Griggs, and State of North Dakota, have invented new and useful improvements in Ladder-Foot Extensions, of which the following is a specication.`

This invention has relation to a ladder, and refers more particularly to devices for adjusting such ladder to uneven surfaces. Persons having constant use for a ladder, such as painters, tinsiniths, or other building artisans, are daily confronted by the problem of findinea sur foothold for their ladder. The ground is frequently uneven enough to cause the foot of the ladder to` slip, and this condition is exaggerated when the ladder is placed on a surface which slopes in more than one direction, such as for example a porch roof.

With these conditions in view the object of my invention is the provision of devices attachable to the bottom of a ladder for adjusting each leg of the ladder to uneven surfaces A further object is to provide an article of this character which may readily be attached and adjusted without having to Another object is to clamp the device on the ladder in an out of the way position when the ladder is not set up for use, so that the ladder may be transported without danger ,of losing the attachment. Finally I aim to provide a broad shoe on my device for the purpose of preventing the ladder from sinking into soft surfaces.

Hereinafter will now Vbe described structures in which are embodied combinations of the advantageous features of the invention, and the said structures are illustrated in the appended drawing, of which:

Figure l is a perspective view'of the bottom portion of a ladder embodying the invention,

Fig. 2 shows, in cross section, the foot of one of the ladder legs with my device attached, as in practice,

Fig. 3 illustrates a ladder adjusted to the sloping surface of a porch roof,

Fig. 4; is a side elevation of my device as it appears detached from the ladder.

Referring in the first instance to Figs. l and 2, it is noted that the legs l and 2 of the ladder are perforated to receive La series Q bolts 3 for supporting the Specification of Letters Patent.

Patented llllay it), 192i..

1920. serial No. 373,954.

adjustable devices e of my invention. Each of tl e said devices comprises, in this case, a strong metal plate having a plurality of key-hole shaped perforations 4a, and the parts are so proportioned that the circular portion of the perforations will pass over the heads of the said bolts 3, when attaching the devices, whereupon the latter are pushed upward, thereby causing the body portion of the said bolts to engage the narrow extensions the keyholes. Nothing further is required in order to attach` the devices, which may be adjusted, as described, to suit all manner of operating conditions. Such adjustment is shown in Fig. 3, which, as stated, exhibits the ladder placed on a sloping porch roof. Above the said lrey-holes is seated, in each plate, a set screw 5 capable of engaging threaded perforations la, 2il of the ladder legs. When the extension plateeL is not in use, or not needed, the said plate is affixed in the lowermost key-holes, whereby the foot of the plate takes a position above the foot of the ladder leg, and the said set screw 5 then comes into alinenient with said ladder perforations la, 2a. rlhis adjustment is shown on leg 2 of Fig. 3. lt is noted that the plate of leg l is extended to support the ladder in a perpendicular position,-

The bottom of the plates is conveniently roughened, as indicated by the teeth Lib, for the purpose of insuring a good foot-hold on a hard or slippery surface. he top of the plate e is bent over to form a guide le on the edge of the ladder, and also for the purpose of strengthening the structure. rlhe bolt 3, as best shown in Fig. 2, is preferably Inade with a shoulder portion 3a abutting a washer 6, for the purpose, and maintaining a sufficient operating space for the extension plate fl. But, of course, any other suitable construction may be substituted, so long as the plate is firn'xly locked in place and is easily slidable in and out.

rlhe extension plates are necessarily made of rather thin metal, and for this reason they are apt to sink into the surface, when the ladder is set on soft ground. In order to lprevent this occurrence l provide a shoe for the devices, and such shoe is indicated by the reference numeral 7 in Figs. l and 4. The said shoe is made with a broad bottom platea, and for strength it may conveniently be made with flanges 7b, 7C. It carriesy a stud 8, which engages perforations of the plate 4, and a Wing nut 9 serves to combine the parts. In this, or other suitable manner, the shoe is rigidly affixed to the extension plate. As the ladder may not always be placed at the sanie angle it is desirable to leave room enough between the said flanges to swing the shoe until it rests squarely on the ground, and so a suicient amount of elearance is allowed, as clearly indicated in Fig. il.

Various Inodilications may be made in the structures described, Without thereby departing :trom the spirit oit the invention. Thus l .lay conveniently inale the eXtension plate from a straight strip of nietal l0, see Fig. 4, in 1vhieh case the top of the said strip is folded over diagonally, as indicated, in order to provide the guide 10b. The dotted outline at the top olf the strip 10 illustrates the shape of the said strip before folding.

l claim:

l. ln a ladder, a series of bolts longitudinally spaced on the ladder legs, a pair of foot extension plates having leyholes for attachment on said bolts, and a set screw in said plates and alinable with threaded per-iterations or" the ladder legs Jor clamping said plates to the legs in elevated inoperative position.

2. A ladder foot extension comprising a body portion'having perforations for adjustable attachment to the ladder legs and provided with guides slidable on and encompassing the front edges of the ladder legs, and a set screw seated in said body for tightly clamping the device on the ladder in elevated out et the Way position.

3. In a ladder, a series oi' bolts longitudinally spaced on the ladder legs, a pair of foot extension plates having key holes for adjustable attachment on said bolts, a stud at the bottoni of each plate, a foot plate mountable on said stud, and a nut engaging said stud for clamping said' foot plate in adjusted position.

il. A ladder` foot extension comprising a body portion having pertorations for adjustable attachment to the ladder legs, provided ivith guides slidable on and enconiH passing the front edges of the ladder legs and having serrated bottoni surfaces to prevent skidding on smooth surfaces, in combination with means for rigidly clamping said extensions on the ladder legs in elevated out of the Way position.

OSCAR ALFRED ALM.

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