US3474881A - Folding ladder - Google Patents

Description

Oct. 28, 1969 J. c. GREEN 3,474,881

FOLDING LADDER Filed Oct. 11, 1967 2 Sheets-Sheet 1 JOHN C. GREEN INVENTOR.

nrronugv 0a.2s, 1969 J.'. GREEN v 3,474,881

FOLDING LADDER Filed Oct. 11, 1967 Y 2 Sheets-Sheet 2 JOHN C. GREEN INVENTOR.

ATTORNEY United States Patent 3,474,881 FOLDING LADDER John C. Green, 2404 Handley Drive, Fort Worth, Tex. 76112 Filed Oct. 11, 1967, Ser. No. 674,428 Int. Cl. E06c 1/00, 1/383; E04g 1/00 US. Cl. 182-24 4 Claims ABSTRACT OF THE DISCLOSURE This invention relates to ladders and has reference to that type of ladder known as a straight ladder, that is, one having single parallel rails and rungs therebetween. Particularly, the invention has reference to a hinged straight ladder wherein sections of the length are jointed whereby the ladder may be compactly folded. The invention relates, in part, to my prior patents, Nos. 3,004,624, and 3,307,652 which issued Oct. 17, 19.67, and Mar. 7, 1967. Both of these prior patents include U-shaped saddles, corresponding to the present pockets, but do not show or suggest how the same may be adapted to a hinged straight ladder.

An object of the present invention is to provide lateral reinforcing means for the joints of a hinged straight ladder.

Another object is to provide, in addition to the foregoing object, means whereby the ladder may be converted into a step ladder or a scaffold.

A further object is to provide braces in a hinged ladder which are received in the sides of the runners when the ladder is not used as a scaffold or step ladder.

A still further object of the invention is to provide a lightweight hinged ladder, yet one which is unusually strong for a given size.

These and other objects of the invention will become apparent from the following description and the accompanying drawings in which:

FIGURE 1 is a side elevational view of a hinged step ladder according to the invention in its extended or straight position.

FIGURE 2 is a side elevational view of the same ladder in its folded position.

FIGURE 3 is a side elevational view showing the ladder positioned for use as a step ladder.

FIGURE 4 is a side elevational view of the ladder converted into a scaffold. I

FIGURE 5 is an enlarged broken side elevational view showing one of the hinges and its reinforcing pocket.

FIGURE 6 is a view similar to FIGURE 5 but showing the hinge in a partly flexed position.

FIGURE 7 is an elevational view taken at a right angle with reference to FIGURE 5.

FIGURE 8 is a perspective view of the hinge and pocket illustrated in FIGURES 5-7, but showing the hinge in its fully flexed or open position.

FIGURE 9 is a broken perspective view of the ladder when used as a step ladder.

FIGURE 10 is an enlarged broken longitudinal sectional view of the inner ends of the braces and showing the same in their latched position.

FIGURE 11 is an enlarged transverse sectional view of adjoining sections of a runner and showing a brace connected therebetween when the ladder is used as a scafiold.

In the drawings the numeral 10 designates spaced parallel side runners which are divided into sections 11, and which sections are connected by hinges 12. Rungs 13 are connected between the runners 10 in the usual manner. The runners 10 are I- beams of extruded aluminum and each is comprised of a web 14 and flanges 15.

In the form of the invention shown, there are four pairs of sections 11 and three pairs of hinges 12 therebetween. The hinge axes are in line with or located outwardly of the front and rear surfaces of the runners 10 and are alternately arranged with respect thereto. Details of the hinges 12 are shown in FIGURES 5-8 and each includes a socket 16 of a shape to receive an end of a stringer section 11. Ears 17 are integral with each socket 16 at corresponding corners, and that end of the socket including the ears extends angularly and transversely at 18 to receive an end of an adjacent runner section 11. As best shown in FIGURE 7, other cars 19 are secured in notches, not numbered, in the flange 15 of the last referred to runner section. A pintle 20 extends through the pairs of ears 17 and 19 to complete the hinge action.

The pocket 21, heretofore referred to, is U-shaped and is open on the side including the hinge 12. Each side of each pocket 21 has flat depending legs 22 and on the runner section 11 on which it is mounted there is a U- shaped spacer 23 beneath the ends of the legs. The width of the pocket 21 is such that it snugly receives the width of the socket 16. There is a planar projection 24 on one side of the pocket 21 and a lateral projection 25 on the other side. A latch 26 is pivotally mounted at one end on the lateral projection 25 by means of a pin 27, whereas there is a notch 28 in the top of the other projection 24 to receive the Latch.

When the described ladder is used as a step ladder, as shown in FIGURE 3, a removable top 29 having flat parallel depending sides 30 may be employed. Notches 31 in the lower edges of the sides 30 engage rungs 13 to steady the top 29. Hinged braces 32 and 33 are pivotally attached to the webs 14 of the end sections 11 by pins 34. As best shown in FIGURE 10, the inner lengths of the braces 32 and 33 are in side by side relation in assembly where they are detachably engaged by projecting pins 35 and 36 received in holes 37 and 38 in the respective braces. Each of the pins 35 and 36 is notched at 39 in one side to prevent accidental lateral displacement of the braces 32 and 33; similarly extending ends of the pins are notched at 40 for use when the ladder is assembled as a scaffold. The arrangement last referred to is best illustrated in FIGURE 11 where a detail of the first described pivot pin 34 is shown. Here, the pin 34 extends through a web 14 of a runner section 11 and there is a coil spring 41 on the extending end of the pin where it is held in place by a washer 42. As shown in FIGURE 4, the hinges 12 outwardly of the center hinge are flexed, at which time the braces 32 and 33 are attached by the pins 34 and 35 as shown in FIGURE 11. A board 44 may be placed on the horizontal inner ladder sections 11 to provide a walk for workmen. When not in use as a step ladder or scaffold, the braces 32 and 33 are received along the ladder webs 14 to which they are pivotally connected and are held in place by the action of the springs 41 and the presence of the flanges 15.

The invention is not limited to the exemplary construction herein shown and described but may be made in various ways within the scope of the appended claims.

What is claimed is:

1. A ladder having a runner along each side and rungs therebetween, said runners being transversely divided into sections, hinges alternately connecting adjoining ends of said sections, the axes of adjacent said hinges being alternately disposed with reference to the front and rear edges of said runners, a U-shaped pocket mounted on corresponding ends of said sections and having their open portions positioned to receive adjoining ends of adjacent sections, latches across said open portions of said pockets and over the respective said adjacent sections when the sections are extended.

2. A ladder as defined in claim 1 and including sockets on the ends of said sections opposite those including said pockets, said sockets being of a size and shape to receive the last referred to ends of said sections.

3. A ladder as defined in claim 1 and comprised of four sections along each side and elongate braces pivotally attached to certain of said sections, at least two of said braces being mounted on each side of said ladder, and means connecting extending ends of said braces with each other and with adjacent said sections.

4. A ladder as defined in claim 1 and wherein each said pocket includes a lateral projection on its extending end and on one side thereof and a planar projection on UNITED STATES PATENTS 641,158 1/1900 Skelley 182-24 1,942,210 l/1934 Harting l8227 3,014,552 12/1961 Fike 18227 3,143,185 8/1964 Wenger 182-27 REINALDO P. MACHADO, Primary Examiner US. Cl. X.R.

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