US2638260A - Flexible ship ladder - Google Patents

Description

May-l2, 1953 T. SKOLMEN El Ag 2,638,260

FLEXIBLE SHIP LADDER Filed July 14', 1952 s Sheis-Sheet 1 525 V ,5 i- 5 v /n 4 I I, I v 2/7 INVENTORS'.

fl 7 4 702652 520045 JOHN 5. EUS'OA/ 5 0 12 12 9' 5: Q 144, L I Y Afro2/v5rs' May 12, 195 3 1'. SKOLMEN El AL FLEXIBLE SHIP LADDER 5 Sheets-Sheet 3 Filed July 14, 1952 INVENTORS.

fi'KOLME/V 2055275 6. EU5'O/V (JOHN ,4 rro ENE/5 Patented May 12, 1953 1.1;; q

I UNITED TE PATENT OFFICE 2,638,260

FLEXIBLE SHIP LADDER Torger Skolmen, George G. Roberts, and John G. Euson, Seattle, Wash.; said Skolmen assignor to said Roberts and said Euson, jointly Application July 14, 1952, Serial No; 298,688

1 Thepresent invention relates to'a pilot?s ladder or the like, often referred to as aJacobs ladder, Such ladders are used over the side of a marine vessel to enable a pilot to board or leave the vessel, and may be used in multiple form for embarkation or debarkation ladders, to be used by ajnumber of soldiers, for example, in a landingoperation. p a I Such ladders in the past have used narrow I rungs, which seldom aiforded a thoroughly firm foothold, A broad rung is preferable, in thatit affords a surer footing, but it entails certain structural complications due to the necessity for preventing the broad tread from. tilting from its generally horizontal position in use. One solution to this difiiculty is to employ two ropes at each end of a broad shelflike tread, but thisis undesirable, as it increases the weight and expense, and increases the possibility of fouling up theseveral lines. It is preferable that a single flexible tensional member, corresponding to the stile of a ladder,'be employed at each end, and it is necessary to provide nevertheless against undue tilting of a broad tread in conjunction ingthe ladder completely apart. Accordinglyit is another object of this invention to provide antitilting means for the individual treads, of such nature and in such form that theywill not make 'difiicult, but indeed will facilitate, the

removal and replacement of a broken tread.

Still further, it is an object to provide antitilti'ng means which, in at least one form, can be readily removed if damaged, and'replaced, and which will eliminate any necessity for'weldingin its:

construction or assembly.

It is, of course, an object of the invention to provide a structure of this nature which is amply strong and rugged, and which will support the tread indirectly, that is, throughthe' 'antitilting' mechanism. The provision of a. structure to the latter ends is an object of this invention. 1,

Since the user of such a. ladder must, or usually will, grasp the stiles while ascending or descending the ladder, owing to the'possibilit'y. that if he grasps the treadsv orrungs he may have "his fingers mashed against the side of thevessel, it

is a further object of this inventionto provide" a structure in which the flexible tensional memhere or stiles are held away from'the'side of.

the vessel, and in' which the antitilting means are themselves a e e ke ei aieee,en ineer 10 Claims. (craze-4o 2 1 so that in addition they may serve as handholds for the user of the ladder.

It is also an object of the invention to provide-a structure which is usable with minor changes either with wire cables as stiles, orwith link chain as the tensional members.

With such objects in mind, and others as will appear more fully hereinafter, our invention comprises the novel ladder, and the novel combination and arrangement of the parts thereof, as

shown in the accompanying drawings in several filed September 18, 1951.

porates many additional ideas not disclosed in forms of execution, and as will be more fully explained hereinafter, and, defined by the claims. Figure 1 is a front elevation of such a ladder, in position of use, with a part broken away in section. to show certain details.

Figure 2'is an isometric view of one end of a tread and its antitilting mechanism, and illustrating the manner in which the tread is supported from the flexible tensional member, which in this instance takes the form of a cable.

Figure 3 is an enlarged vertical sectional view along the line of the cable and lengthwise of the tread, as indicated at 3-3 in Figure 2, illustrating details of construction.

Figure 4 is a horizontal sectional view of a tread and associated parts, as indicated by the line 44 in Figure l. I t

Figure 5 is an end elevational view of a modified form of construction.

Figure 6 is an end elevational view of the invention adapted for support by a link chain,

rather than by a cable, and Figure '7 is an isometric "view of the same form, while Figure 8 is a sectional view similar to Figure 3, taken on the line 8-8 of Figure 6, illustrating the same arrangement.

Figure 9 is an exploded isometric view of a further modified arrangement, and Figure 10 is an isometric view of the same arrangement with the parts assembled and in operative relationship.

The present invention is to a degree related to the copending application of Torger Skolmen, one of the inventors herein, Serial No. 247,121,

However, it incorthat earlier application. Like the earlier application, it is intended that the principles of this invention shall be incorporated, if desired, in multiple ladders, and it is believed that it will be obvious how that may be done after the principles of the present invention have been dis-,

closed.

In Figures 1 to 4 the ladder is shown as incorporating stiles I, constituted by single lengths of wire cable, one at each side of the ladder. These are provided at their upper ends with securing means, as indicated at in, and the exact form thereof is immaterial. Similar securing or lashing means may be provided at l 0a atthe,

lower end. At spaced vertical intervals broad flat treads 2 are provided, which preferably are of wood. Each may be centrally apertured for purposes of drainage and to provide a handheld, as indicated at 2B, and its upper surface may be grooved or scored, as indicated at 2|, for better foothold. Such details are not particularly important. At each end, intermediate its front and back. edges, each tread is apertured, preferably by notching it inwardly from the end, as is indicated at 22. This notch receives the cable I, and should be made large enough to receive an enlargement such as the collar at H. This collar may be held in place by swaging it and crimplo it inwardly upon the cable I.

In order to int'erengag e' the enlargement H with the tread 2, and so to support the tread from the cables 3, we provide a frame, generally indicated by the numeral which preferably is D-shaped in marginal outline, so as to provide a flat side that contacts flat surface of the tread, across which it extends transversely, and a rounded portion which extends upwardly or downwardly from the tread, as the case may be, to engage the cable l or tensional member at some distance from the tread. While this frame 3 might be solid, that is, of imperiora-te form, it preferred that it be made skeletonlike, of a strap of metal bent in the form of a stirrup,

whereby to provide the fiat portion 32 and the rounded portion 31, for the purposes already indicated. In the preferred arrangement one such stirrup extends above the tread and the other extends below it at each end of each tread.

The frames 3 ae intere'ngaged with the cable i at two points, at the tread by the flat portion 32, and in the rounded portion 32. To this end it is preferred that these portions be notched in alignment with the location of the cable, a notch 33 being indicated in the flat portion at 32 and a notch 3:2 in "'ie rounded portion 35. It will be observed (see particularly Figures '2 and 3) that these notches enter each individual stirrup 3 from opposite edges. This facilitates application and minimizes the danger of accidental disengagernent, However, means are provided to prevent disengagement of the cable from the upper notch 34 such as the notched clip 35, which closes the open end of the notch and is bent around and clipped to the opposite edge of the frame 3. The notch in the clip enables it to he slipped on from the side opposite the not-ch 2-24, to thereby encircle the cable.

The notches and 33, it will be noted, are just large enough to span the cable i without chafing, but are small enough that the enlargement 33 may not pass through the notches 33 By securing the frames 3 to the tread, in the assembly described, the cable i through the enlargements or collars 33 will support the individual treads 2. Such securement is accomplished by bolts 11 and their nuts it, which bolts pass through the fiat portion oi the upper frame 3', through the end of the tread (where holes are provided for the purpose), and through the flat portion 32 or the lower frame, and the nuts lil are applied to hold all parts thus clamped together and in however, a tread is broken, it is only necessary to remove the bolts 4, whereupon the frames 3 may he slipped :along the cable away from the broken tread, this can be withdrawn endwise, and a new tread can be similarly put in place and clamped and. held by the same bolts and between the same frames.

In Figure 5 is shown a slight modification in that the flat portion 32a of the stirrup 3 extends beneath and supports the end of the tread 2 from below, as in a hanger. A short complemental strap 32b contacting the upper surface of the tread, and held to the stirrup t and to the tread by the same bolts 4, completes the assembly.

In Figures 6, 7 and 8 the structure has been modified to the degree necessary to permit the flexible tensional member to be constituted by a link chain. In allother essential respects it is virtually identical with the construction shown in Figures 1 to 4 inclusive. Herein the chain is of a conventional'type, indicated generally by the numeral 13, and consisting of individual links secured together by a locking arrangement which constitutes an enlargement I l. One such enlareenrent may be'einployed for supporting interengagem'ent with each tread, at each end of the tread, in ieu-of the collar ll. Because the links, where they pass through the rounded portion Si or a stirrup, are somewhat broad, it is preferred that the clips 3511 include a central tang 3%, which extends through the link and which in some instances, as for instance at the bottom of Figure 6, may assist in the support of the tread and its stirrup frames. Likewise the notch in the hat portion 32 of each D-frame is similarly formed with a central tang 320, which slips through the aperture in a link, and which cooperates with an enlargement M to assist in the support of the tread.

In Figures 9 and 10 the arrangement is further modified by making each stirrup frame in two separate and separable parts, which will eliminate welding in the frame and will facilitate the replacement of an injured stirrup by making it possible to remove and replace a stirrup without threading it on from the end of the flexible tens'ional member. Thus the stirrup 3a is flanged inwardly, but only part-way across, as shown at 31), but the flat portion of the stirrup is completed by a separate flat strap 32a in which is formed the notch 33. The notch 3 3 is formed as before in thereunder! portion 31 of the frame 3a. By providing the flat strap 32a and the flanges 3b with registering holes, which also register with the holes provided in the end of the tread 2 for the reception'or the bolts #1, the entire assembly may be clamped and held together in the manner shown in Figure 10, and in this relationship parts are substantially as strong and solid as in the form of Figures 1 to 4 inclusive, or of Figures 6 and 7. However, if it becomes necessary to remove any given stirrup it is only necessary to disassemble parts in the manner indicated in Figure 9, whereupon each fiat strap 32a can be removed, the frame 30, can be removed from the cable, and all par s are thus cornpletely separable from the cable. New parts can be replaced in the same way. Indeed, even though the remainder of the stirrups are of the types previously described, should it become necessary to replace them, they can be removed by cutting through them so that they may pass off the cable orchain, and a replacement stirrup of the type shown inFigures 9 and 10 may be applied readily.

It will be evident that a double stirrup frame of the type indicated, or even a single stirrup as in Figure 5, will engage the cable or chain at a suflicient distance from'its point of support of the tread that a weight placed near the edge of the tread will not unduly tilt the tread, for it is resisted by this distant point of engagement of the stirrup. Thus a broad tread may now be used, with only a single tensional support intermediate its front and rear edges. Furthermore, these stirrups serve to space the chain or cable away from the side of the vessel, so that the user may grasp the chain or cable as he uses the ladder. The elongated aperture 20 also may serve as a, handhold, and although the stirrup frames extend some appreciable distance up and down the cable or chain, these stirrup frames,

.being skeletonlike, themselves constitute good handholds.

It is contemplated that such frames may be made of light metal, such as an aluminum alloy, and in this form will possess ample strength-and yet will be in the aggregate of light weight. ,It is calculated that by thus using aluminum inw stead of steel for the frames the weight of a fortyfoot ladder can be lessened by at least sixty pounds. Also, and particularly if the form of Figures 9 and 10 is employed, no welding is necessary, and welding is sometimes objectionable with aluminum, particularly for marine work, and

hence the construction of Figures 9 and 10 is not only useful for the purpose of ready replacement of an injured stirrup frame, but also it is useful because it permits the use of aluminum for the stirrup frames without the necessity of any weldmg.

We claim as our invention: 1

1. A pilots ladder or the like comprising a plurality of broad treads of like length which in use are located at spaced vertical intervals, two flexible, tensional supporting members extending vertically along the opposite ends of said treads, located intermediate their front and rear edges, a pair of D-shaped frames at each end of each tread, one disposed transversely above and one transversely below such end, and contacting the respective surfaces of the tread along the flat sides of the respective frames, means joining the treads ends to the frames in such relationship, means supportingly interengaged between each tensional supporting member and the fiat side of i one such frame at the corresponding end of each tread, to sustain a load placed upon the tread, and retaining means interengaging the rounded side of each frame with the corresponding tensional supporting member.

2. A pilots ladder or the like, as defined in claim 1, characterized in that the ends of each tread are notched for the reception of the respective flexible, tensional supporting members, and the mean which join the tread and the D- shaped frames are releasable, whereby anew tread may be substituted for a broken one by such release and endwise withdrawal of the broken tread, and similar engagement and securement of the new one.

3. A pilots ladder or the like, as defined in claim 1, wherein the frames are each skeletonlike, resembling a stirrup, and thereby afford handholds adjacent each tread.

4. A pilots ladder or the like comprising a plurality of broad treads of like length which in use are located at vertically spaced intervals, two flexible, tensional supporting members extending vertically along the opposite ends of said treads,

located intermediate their front and rear edges, two D-shaped stirrups of strap material, one disposed transversely above and the other transversely below each end of each tread, and contacting the respective surfaces of such tread along the fiat sides of the respective stirrups, through bolts and securing nuts joining and securing together the fiatsides of the upper and lower stirrupsand the tread therebetween, each such fiat side and each rounded side of each stirrup being apertured for the passage of the corresponding tensional supporting member, and each tensional supporting member including an enlargement supportingly engageable beneath a fiat side of a stirrup at each end of each tread.

5. A pilots ladder or the like as defined in claim 4, wherein each stirrups apertures for the reception of the tensional supporting member are formed as notches opening from an edge of the stirrups strap, and a retaining means removably securable to the stirrup to close each such notch in the rounded side of each stirrup.

6. A pilots ladder or the like as .in claim 5, wherein the notches in the rounded side and in the flat side of each stirrup open from respectively opposite edges of the stirrup-forming strap.

7. A pilots ladder or the like as in claim 4, wherein the flat side of each stirrup is a separate piece from the rounded side thereof, flanges directed inwardly from each end of the rounded side to overlie said separate flat side, the flanges and the flat side being both apertured for the reception of the through bolts, whereby the assembly is secured together.

8. A pilots ladder or the like as in claim 4., wherein each tread is notched inwardly from its ends for reception of the tensional supporting member, and the aperture in the flat side of each stirrup is also formed as a notch opening inwardly from the edge of the stirrups strap, the notch opening in one stirrup at least being directed oppositely to the notch opening in the corresponding end of the tread.

9. A pilots ladder or the like as in claim 4, wherein the tensional supporting members are in the form of chains, and the flat and the rounded sides of each stirrup are notched inwardly from the edge of the stirrups strap to receive the links of such chains, and a retaining means removably securable to the stirrup to close at least one such notch in each stirrup, and. formed with a central tang which in use projects through a chain link.

10. A pilots ladder or the like as in claim 4, wherein the tensional supporting members are in the form of cables, and include swaged-on collars at vertically spaced intervals, and each tread is notched inwardly of its ends to receive said collars, to bear beneath the stirrups flat portion thereabove, and through which the cable extends.

' TORGER SKOLMEN.

GEORGE G. ROBERTS. JOHN G. EUSON.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,206,753 Roth July 2, 1940 2,296,441 Hopp et al. Sept. 22, 1942 2,348,906 Hopp et a1 May 16, 194A;

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