US1829980A - Ladder - Google Patents

Description

' Nov. 3, 1931. c. B. BURGESS LADDER Filed Ma 21, 1928 //Vl NTO 64 0: 5. 5026555 2r M M H/5 A TTOE/VE forming part of the specification.

Patented Nov. 3, 1931 UNITED STATES CLYDE B. BURGESS, 0F CLOVEBDALE, CALIFORNIA LADDER Application filed. May, 21,

My invention relates to ladders having a prop or support at the back, and particularly to ladders which must be used upon a sloping or uneven support, as is often the case in fruit picking and similar work.

An object of my invention is to provide a ladder which will stand firmly upon sloping or uneven ground.

Another object of my invention is to provide a ladder having a prop which is stressed in pure compression and whose strength is, therefore, exerted to maximum advantage.

Still another object of my invention is to provide a ladder which is light and convenient to handle.

My invention possesses other objects and valuable features, some of which will be set forth in the following description of my invention which is illustrated in the drawings It is to be understood that I do not limit myself to the showing madeby the said description and drawings, as I may adopt varying forms of a my invention within the scope of the claims.

Referring to the drawings:

Figure 1 is a-perspective view of the upper part of a ladder embodying my invention, and Figure 2 is a longitudinal section of the same; the plane of sectionbeing indicated by Y the line 2-2 of Figure 1.

Broadly considered, my invention comprises a prop-bracket attached preferably adjacent the top of a ladder and mounted for pivotal movement about an axis transverse to the ladder. A prop is movably attached to this prop-bracket, and there is also preferably provided a retainer or guide for limiting the motion of the prop with respect to the prop-bracket.

When such a ladder is set up it is stable regardless of inequalities of the ground on which it stands, and even tho it be on steeply sloping ground the prop may be arranged to give as full a measure of support as on I: the flat. Moreover, owing to its method of attachment no bending moments are induced in the prop, which may, therefore, be designed with the economy in welght permitted with a strut in pure compression.

A preferred form of my invention combracket for preventing movement of said 1928. Serial No. 279,250.

prises a ladder having side rails 6 between which are arranged the transverse steps 7 A top step 8 extends beyond the side rails and is supported and braced by the fixtures 9.

Transversely of the ladder between the side rails is a prop-bracket comprising preferably an angle-bar 11, the ends whose webs are bent outward at right angles to form lugs 12 and 13. The lugs 12 are provided with holes thru which pass the bolts 14 which secure the prop-bracket to the side rails and. which pivot it for rotation about an axis parallel to the angle-bar and transverse of the ladder. A wear-plate 15 is secured to the side-rail under the lug 12 to prevent abrasion even under long use.

Secured to the lugs 13 by its ends 16, which are bent inward at right angles for the purpose, is a guide or retainer bar 17. Rivets 18 or welding may be used for fastening the 70 bar to the lugs. There is thus formed, between the angle-bar 11 and the bar 17, a slot 19 thru which a prop 21 passes.

The prop is pivotally mounted by a bolt 22 to the apex of an angular strap 23 which is secured to the web of the angle-bar 11 and projects above it toward the top of the ladder. The prop is thus free to move with respect to the prop-bracket about its axis and in the slot 19, but movement normal to this plane is prevented, the bracket rotating on its own axis instead. Bending stresses on the bolt 22 and on the prop are thus prevented.

From the above description it is apparent that the prop may be so adjusted as to give 85 full support whatever the slope of the ground on which the ladder is placed.

I claim:

1. A ladder, a prop-bracket mounted for pivotal movement about an axis transverse of said ladder, a prop for said ladder pivotally mounted to said prop-bracket for movement about an axis perpendicular to the plane of said first axis, and means on said propprop with respect to said prop-bracket in a direction normal to the axis of the propbracket. i

2. A ladder, a prop-bracket mounted for pivotal movement about anaxis transverse of said ladder and having a slot therein parallel to said axis, and a prop Working through said slot and movably secured to said prop-bracket.

3. A ladder, aprop-bracket mounted for pivotal movement about an axis transverse of said ladder and having a slot therein parallel to said axis, and a prop Working through said slot and pivotally secured to said prop-bracket above said axis.

In testimony whereof I have hereunto set my hand.

CLYDE B. BURGESS.

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