US2397950A - Ladder - Google Patents

Description

April 9, 1946. N. l.. DAHLANDER LADDERl Filed Aug. 22, 1944 n INVEN-roR NOEL L. DAHLANDER BY W ATTORNEY Patented Apr. 9, 1946 UNITED STATES PATENT OFFICE LADDER f Nox'L. Demander, New Milford, Pa.

I Application August 22, 1944, Serial No. 550,544

4 Claims.

This invention relates to ladders in general,v

both single and multiple, so extensively used today on vessels for emergency debarkation purposes.

Among the objects of the lpresent invention it is aimed to provide an improved ladder suitable not only as a single or pilots ladder, but also as a multiple or debarkation ladder having rigid metal rungs, exible suspensory elements such as chains Aand pivotal connections between the chains and the suspensory elements.

It is still another object of the present invention to provide an improved rung for a marine ladder, whether single or multiple, which may conveniently be pivotally connected to the suspensory elements and composed of sheet metal folded back upon itself for reenforcement purposes and reversible to serve as a step whether the ladder is suspended in normal position with its upper ends at the top or in reverse position with its lower ends at the top, the reversible feature being particularly valuable when an emergency debarkation is required at night, at which time, in the interest of protection, as little illumination as possible is used, with the consequent diiculty of securing a ladder of this type in place if its usefulness was not satisfactory unless suspended in one and only one way.

- It is still another object of the present invention to provide an improved rung for a marine ladder, whether single or multiple, and `converting the T-shaped construction disclosed in the co-pending application for patent, Ser. No. 547,- 830, filed August 3, 1944, into a reversible rung whereby the ladder equipped with such rungs may be used whether theV ends ofthe suspensory elements normally at the top are at the top or at the bottom.

These and other features, capabilities and advantages of the invention will appear from the subjoined detail description of specifieembodiments thereof illustrated in the accompanying drawing in which Figure 1 is a front elevation of a ladder equipped .according to one embodiment of this invention.

and '2 and rungs 3 pivotally connected to said Fig.,2 is a fragmental enlarged front elevational Fig. 7 is a, fragmental diagrammatic view of a suspensory members I and 2. The suspensory members I and 2 preferably are lleXible and in the present instance are shown as composed of chains of the Lock Link type connected to the lash receiving rings 4 at their upper ends, and the chains are'preferably covered with socks or envelopes 5 composed of a suitable fabric material such as canvas, see the co-pending application for patent, case #12, of Frederick A. Ellis, Serial No. 547,830led August 3, 1944.

The rungs 3 in this embodiment are shown as composed of two pieces of sheet metal 6 and 'I,

the piece 6 having a lower flange 8 folded under the tread portion 9 which continues into another flange IIl and then terminates in a shank portion II. The ends, or rather edges, of the tread portion 9 with their reenforcing anges 8 and I0, are slightly inclined toward the shank portion II as shown at I2 and I3. To this piece 6, the lpiece l, substantially identically constructed, is secured, it being secured to the piece 6 by welding or the like. The piece 'I consists of the flanges I4 and I5,tread'portion I5 and shank portion I'I, the shank portion ,|'I vbeing secured adjacent to the shank portion II so 'that these pieces 6 and I complement one another to form an H or I formation in cross section.

In this embodiment the loops I8 and I9 formed at the ends of the rungs 3 are integral with and continuations of Athe shank portions II and I1,

respectively, the loop I8 being an integral part of the strip 20 which is folded over and secured by a rivet 2I cr the like to the shank portions I'I and II,- the loop I9 in turn being an'integral part of the strip 22 which is folded over and secured by a rivet 23 or the like to the shank portions II and I1. n

Excellent results have been achieved when the rung just described is composed rof steel ranging from .031 to .037 inch in thickness, with the steel being galvanized.

In the embodiment shown in Figs. 5 and 6, the loops 24 and 25 are parts of separate clips, the loop 24 having the side arms 2B and 27 and the loop 25 having the side arms 2B and 29 secured to the shankportions 30 and 3l by rivets 32. Preferably, as shown in Fig. 5, two rivets 32, 32 are provided for each loop forming clip 24, 25,

the Shanks 30 and 3| being portions of the piecesl 33 and 34 similar to the portions 6 and 1, respectively, of the embodiment illustrated in Fig. 3,

, except as already set forth that the loops 24, 25

are parts of separate clips in the'embodiment shown in Fig. 6 and in the embodiment shown in Fig. 3 the loops I8 and I9 are integral parts of the pieces 6 and 1, respectively.

When the loop forming clips 24, 25'are separate from the pieces 33 and 34, the pieces 33 and 34 need not be welded to one another, but may depend upon the rivets 32 for securing them to one another. Excellent results have been of sheet steel having a thickness ranging from .031 to .037 inch and the clips forming the loops" achieved when the pieces 33 and 34 are composed link portions of the suspensory members, said clips also having arms riveted to the ends of said shanks.

2. The combination of a plurality of suspen- 'tween tread portions, and galvanized steel clips 24 and 25 have been composed of sheet steel I having a thickness ranging from .078 to .125 inch,

and all pieces suitably galvanized.

On the other hand, excellent results have also been achieved when the pieces 33 and 34 wereV composed of sheet aluminum having a thickness of about .081 inch lwhen the clips forming the loops 24` and 25 would be made of steel approximating .125 inch, with the clips galvanized.

Excellent results have also been achieved When the H or I construction formed by the sections 33 and 34 wei'e made in one piece of aluminum, either special rolled or in a casting, having a mean thickness of .156 to .162 inch.

In the embodiment shown in Fig. 7, there is illustrated a multiple ladder-in which the rungs- 35 secured to the suspensory members 36, 3'land 38 have the same H or I formation in cross section as the embodiments illustrated in Figs. 3 and 6. With the multiple ladderthe clips forming the loops I8, i9 or 24, 25 mayeither be integral with the rungfproper as shown in Fig.` 4, or separate as shown in Fig. 5. With a rung having an I shape in cross section, a tread will of course be inA position for use, that is, face upwardly whether the normal upper ends of the ladder are secured at the top or whether the normal lower ends of the Vladder are secured at the top, thus forming a reversible ladder `not only having all ofthe advantages of a rung T shape in cross section, but additional advantagesflowing from the added strength that is made pos-`A sible with an I shaped construction as compared to a T shaped construction.

It is obvious that various changes and modiications mayv beu made to the details of construction without departing from the general spirit of the invention as set Vforth in thev appended claims.

I claim: i

1. The combination of a plurality of suspensory members composed of chain, links, rungs, each rung composed of two sheets of metal, each sheety consisting of an upper tread portion, a short extension, and a long extension,` the short extension being folded back into intimate vengagement with the-lower face of `about'one half of said tread portion, the long extension being composed of two webs lbent into'a dihedral right angle, with one web folded back into intimate engagement with the other half of the lower' -face of said tread portion, and the' other web extending at'right angles to said tread portion to form a single thickness shank, the Shanks being at the ends of each web portion having loops to form journals. for parts of the chain links and maintaining the tread portions at the top and bottom in the interest of reversibility.

3. The combination of a plurality of suspensory members, reversible rungs I shaped in cross section with thecross pieces formed at `the top and bottom of the intermediate web, each rung composed of rtwo sheets of metal, each sheet consisting of an upper tread portion, a short extension, and a long extension, the short extension being folded back into intimate engagement with about half of the lower face of said upper tread portion,V the long extension having two websforming a dihedral right angle with one webV folded under and in intimate engagement with the lower face of the other half of said upper tread ,portion and the other web Vextending at right angles to said upper tread portion to form a single thickness shank, the Shanks forming anchoring means Vfor the two sheets of metal, and

being secured to one another in intimate engagement with one another to form an intermediatedouble thickness Webbetween the tread portions,

and clips at the ends ofthe intermediate doublev thickness web portion having loops forming journals 'for link portions of the suspensoryl members, said clips -also havingA arms riveted to theY ends of, said double thickness intermediate Web.

4. The'rcombination oi a plurality of flexiblesuspensory members, reversible rungs, each rung composed of two sheets of metalLeach sheetconsisting `of an upper tread portion, a shortextension, and'along extension, the short extension havingY two webs forming a dihedral-right angle including a long web and ashort web, thel extension having two webs forming a dihedral right angle with one another, one we b being folded backvinto intimate engagement with the other half of the low-er face of the Asaid tread portion and the other web extending Aat right anglesto said tread portionin intimate engagement with theY other web oi said short extension,

and then extending beyond thel said short Vlex-f tension to form a single thickness shank, the shanks forming anchoring means for thef two sheets of metal and being secured to oneanother to form "an intermediate double web portion'betweenfthe tread portions, and clips vat theends of the intermediate web portion having loops forming journals for link portions of the 'suspensory members, Ysaid clips l'also having arms riveted lto the ends of 'saidintermediate double thicknessweb. i i .v

Y NOELL'. DAHLANDER.

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