US2333849A - Ladder construction - Google Patents

Description

NQV. 9, 1%43. s DRISCOLL 7 2,333,849

' LADDER CONSTRUCTION Filed June 13, 1941 2 Sheets-Sheet l SAYRS LDEISCOLL.

NW. 9, 1943. E RISCOLL 2,333,849

LADDER CONSTRUCTION Filed June lb', 1941 2 Sheets-Sheet 2 SAYES E. DEISCOLL Patented Nov. 9, 1943 UNITED STATES PATENT" OFFICE.

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Application June 13, 1941, Serial No. 397,981

2 Claims. (01. czar-3s) This invention relates to ladders, and is more particularly concerned with a ladder, the'structure of which is so modified as to render it adaptable to secondary uses.

In the manufacture of ladders which are to serve additionally as barriers, bridges, skids or the like, it is customary to vary conventional structure in a manner to insure a broadened field of utility. Of course, such modifications of structure inherently involve a compromise, the goal of which is to maintain unimpaired the best features of each of the structures which the combination device is to replace. As the art now stands, this goal has never been attained, known ladder constructions of plural utility being defective in the performance of either one or both of the intended functions. In other words, the utility and strength of a ladder are usually, at least in part, sacrificed in Order to render the structure more versatile.

A ladder which may have an additional function has been found particularly desirable for employment in'c'onjunction with trucks, freight cars and the like in which there is provided a load carrying bed or floor which is disposed in a plane lying a substantial distance above the plane of the road surface. In such vehicles it is common to provide a barrier surrounding the load carryingfioor and it is highly desirable to have some means to bridge the gap between the fioor and the road surface during loading. As a consequence, it has been proposed to so modify a portion of the barrier that it may be used as a ladder during loading operations. Such constructions are now known but the full advantage of the combination construction. is not attainable because those constructions characterized by simplicity,

have been found to be lacking in essential strength, while those of suflicient strength are of such complexity as to render their use undesirable from a cost standpoint.

It is, therefore, an object of this invention to provide a ladder of novel construction characterized by great rigidity and strength without/loss of adaptability to secondary functions.

According to this invention, it is contemplated that a barrier structure of wide adaptability be provided, the said barrier structure serving additionally as a ladder to permit access to the'fioor level of the enclosure. By the employment of this invention, the, provision of a combination truck tail gate and ladder of superior constructionv is contemplated, the construction being of unimpaired utility. in each of its functions.

It is a further object of this invention to provide a ladder, the steps of which may be folded into a plane parallel the plane of the uprights, while, at the same time, the steps may be rigidly reinforced when in operative position.

Other objects and advantages of this invention will be apparent upon consideration of the "fol lowing detailed. description thereof in conjunction with the annexed drawings wherein:

Figure 1 is a perspective view of a portion of a truck body showing a preferred type of tail gate constructed in accordance with this invention,

-the tail gate being in position to act as a-barrier;

Figure 2 is a perspective view similar to Figure 1 but showing the tail gate in position to function as a ladder, the steps being let down to operative position; I

Figure 3 is a detail view in side elevation of the lower end'of a tail gate stave showing the hook construction of the present invention by which the tail gate is fastened to the truck bed when the former is functioning as a ladder;

- ings, it will be seen that the illustrated form of the invention consists primarily of two uprights or staves l0 connected by upper and lower rigidly attached slats l2 and i3, respectively. Intermediate slats l2 and it further slats Hi are provided, each of these being hinged to uprights ill in a manner to be hereinafter described. As shown in Figure 1, the uprights iii are adapted for coaction with the bed or floor of a truck of conventional construction. As illustrated, and as is customary, the end of a truck bed is normally provided with straps Ila-for the reception of staves which normally maintain the tail gate in position. The ends of uprights ID are, therefore, provided with integral portions of increased cross-section it for close reception within straps I5. Each enlarged portion [6 is hollow and generally rectangular in form, while the remainder of each upright It is arranged in channel form as illustrated in the various figures of the drawings. By this arrangement, the maximum rigidity of the upright is attainable togetherwith a close fit between the socket defined by strap it and the thickened portion it of each upright. In the position shown in Figure 1, the tail gate construction is held against lateral movement by the straps I 5 and against downward movement by slat it which is rigidly attached to both uprights it! and which consequently acts as a stop to prevent their passage through strap l5, the bottom edge of the slat resting on the flooring of the truck. In order to facilitate insertion of portionsit of uprights it within straps I5, one face of the enlarged portion is beveled as shown in Figures 3 and 4.

Having now discussed in conjunction with Figure 1 the-position and function of the present invention as a tail gate, reference is now made to Figure 2 in which the operation of the device as a ladder is illustrated. It should be noted that each upright in is provided with arounded hook H, the shank of which is bolted, riveted, or otherwise attached thereto. As illustrated in Figure 3, bolts l8 may be conveniently used for this purpose, the shank of the hook being inserted within the hollow rectangular portion i6. These hooks function. to attach the uprights iii to the straps i5 when the tail gate construction is disposed in the manner indicated in Figure 2. As before, slats l2 and i3 serve in part to maintain the rigidity of the construction. It will be noted, however, that the various stepmembers l4, which, in Figure 1 were disposed in a plane parallel the plane of the uprights, in Figure 2 are disposed in a plane substantially transverse the plane of the uprights. This movement is accomplished by gravity and is made possible by the construction best illustrated in Figure 5.

It will be seen that each step member I4 is provided with a hinge l9 consisting of leaves 20 and 2| pivoted together for movement about a pin 22. Leaf 20 of each hinge underlies and is connected to the lower surface of a step member ll, the step member extending inwardly toward the upright ID to a point just short of the barrel formed by portions of leaves 20 and ii where they surround pivot pin 22. On the other hand, the leaf H is permanently attached to a portion of the upright. This may be done by .the use of bolts or by welding or any other suitable manner. In operative position the leaf 2! of each hinge extends above the step which is attached to the other leaf 20 of hinge IS. The upper end of each leaf 2| is bent outwardly from theface of upright l and with that face forms a groove. This groove is clearly seen in Figures and 6. The length of leaf 2| between the axis of rotation and the bent out portion is conveniently equal to the width of the step to permit nesting as shown in Figure 6. It'can now be seen that each step member It, being hinged. to both uprights III by a construction such as that shown in Figure 5, is movable from the position of Figure 2 to the position of Figure 6 at which time it lies in a plane parallel'the plane of upright It.

In order that each step member ll may be supported in it's operative position, hinge 23 is provided this hinge having a leaf 24 resting against a portion of leaf 20 and being attached therethrough to step member I. The other leaf 25 of hinge 23 is normally free, but when step member I4 is moved to operative position it will follow the path indicated in Figure 6 and will be. received in the groove formed between the upright In and the bent out portion of the leaf ii of the hinge on the step directly therebelow. Leaf 25, when received in this groove as shown in Figure 5, serves to support step member ll rigidly in position.

. From the foregoing description, the operation of the described form of this invention is apparent. Ifit is desired to use the tail gate of Figure 1 as a ladder as shown in Figure 2 for the purpose of facilitating loading of the truck,- it is only necessary to raise manually uprights It to unseat portions l6 from within straps Ii. Thereafter,

about its hinge It to a position at right angles to the uprights in. It is then only necessary to insert the leaves 25 of the various hinges 23 in the appropriate notches to insure maintenance of the steps in position to resist any strains to which they may be subjected.

The lowermost of the step members I4 is, of course, provided with a hinge 23, the notch for leaf 25 of this hinge being merely the upper edge of slat I2 and the appropriate portion of uprights in.

If the device of the present invention is not to be subjected to great strains, the hinges I! may be used without support, it being necessary only to employ a hinge of conventional type which will open only ninety degrees. It will be realized that but one preferred embodiment of this invention has been described and that many modifications of the structure shown may be made within the scope of the appended claims.

What is claimed is:

1. A ladder construction comprising, a pair of spaced uprights, step members extending there-- between, hinges connecting each of said members to each of said uprights to render the members movable to and from a position parallel to the plane of the uprights and an extended step forming position substantially transverse thereof, the hinge on-each upright having its upper end bent outwardly to form with the respective upright a notch above the step member, and a pair of I means each pivotally attached to a step member in a position to register with the notch directly therebelow, said means each being adapted, when the step member is in extended position, to engage a notch therebelow, each of said means being of a width not greater than that of the corresponding upright, whereby each step mem-' rights to render the step members movable to and from a position parallel to the plane of the.

uprights and an extended step forming position substantially transverse thereof, each hinge having its upper end bent outwardly to form with the respective upright a notch above the step member and a pair of plates pivotally attached at one end to the underside of each step member forward of the marginal connection to an upright, said plates being spaced apart a distance equal to the spacing between the notches therebelow so that the free end of each plate may fit in a notch when the step member is in extended position, the plates so held serving to support the step members to which they are attached, while being readily disengageable when the step-members are SAYRS E. DRISCOLL.

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