US2943696A - Pilot's ladder and the like - Google Patents

Description

July 5, 1960 G. G. ROBERTS PILOTS LADDER AND THE LIKE .File d Jan. 31, 1957 3 Sheets-Sheet 1 INVENTOR.

GEORGE 6- ROBERTS ATTORNEY ys, 1960 G. cs. ROBERTS 2,943,696

PILOT'S LADDER AND THE LIKE Filed Jan. 51, 1957 5 Sheets-Sheet 2 INVENTOR. GEORGE a. ROBERTS A 7' TORNEY y 9 G. e. ROBERTS 2,943,696

PILOT'S LADDER AND THE LIKE Filed Jan. 31, 1957 3 Sheets-Sheet 3 INVENTOR.

GEORGE 6. ROBERTS ATTORNEY United States Fatent O PILOTS LADDER AND THE LIKE George G. Roberts, 4152 Jtlelifferson St., Redwood City, Ca

Filed Jan. 31, 1957, Ser. No. 637,536

8 Claims. (Cl. 182-196) This invention relates to improvements in ladders with flexible stiles, such as a pilots ladder (also called a Jacobs ladder or an embarcation ladder), which is hung over the side of a ship to enable a pilot to board and leave the ship.

One reason why pilots ladders are made with flexible stiles is so that they can be collapsed and stored when not in use. However, the pilots ladders heretofore in use have formed a bulky roll when they were collapsed because excessive space was consumed by the rungsupporting frames (also known as spacing ears). I have now solved that problem by providing a rung-supporting frame or ear of novel structure, which also serves as a handgrasp stirrup and a lashing ring. This new stirrup enables attachment to flexible tensioning members, such as chains, in a new way that makes it possible to fold the ladder into a minimum amount of space instead of coiling it. As a result of my invention, the folded ladder consumes much less space than the rolled ladders heretofore in use.

Manufacture and assembly of my new ladder is especially easy, inexpensive, and rapid because each rung and stirrup assembly is secured to the flexible stiles by a single meansone bolt and nut or one rivetat each stile.

An important feature of my invention is that an additional connection and steadiness is obtained by the fact that each stirrup itself passes through a stile at a spaced distance from the single securing means, instead of having a second bolt or rivet or a special clip.

Manufacturers of pilots ladders have also been 'confronted heretofore with the problem of having to fabricate a large number of different parts; the very number and the fabrication of these parts has increased the manufacturing and assembly costs and the time of assembly. My new ladder has fewer parts, and most of these parts are more easily and inexpensively made than the parts of pilots ladders heretofore in use. The net result is that my ladder is not only better than any pilots ladder heretofore available, but is also substantially less expensive.

At the same time, my invention makes it easy to re- Another object of the invention is to provide a strong and safe pilots ladder at low cost.

Another object is to provide a pilots ladder in which the stirrup is made in one piece, passes through the stile at about its midpoint, and is bolted to the stile and rungs by a single means adjacent its open end.

Other objects and advantages of the invention will appear from the following description of a preferred embodiment.

In the drawings:

Fig. 1 is a view in front elevation of portions of a ladder embodying the principles of the invention, the ladder being broken because of space limitations. By way of example, chain stiles are shown in this form of the invention.

Fig. 2 is a view in end elevation of the ladder of Fig. 1.

Fig. 3 is an isometric view, on an enlarged scale as compared with Figs. 1 and 2, of one of the handgrasp stir rups showing its attachment to the chain stile and the rungs.

Fig. 4 is a view in end elevation, partly' in section, showing a modified form of the invention, employing wooden rungs instead of hollow-metal rungs and a modified form of stirrup.

Fig. 5 is a perspective view of a clip used in attaching the stirrups to the chain stiles in the form of the invention shown in Figs. 1-4.

Fig. 6 is a view in end elevation similar to Fig. 4 showing another modified form of stirrup having no lower support member.

Fig. 7 is a perspective view of a ladder rung made of a single piece of wood or metal with notched ends, the stirrups being shown in broken lines.

Fig. 8 is a view in end elevation, similar to Fig. 6, showing another modified form of stirrup, having integral spacing means so that no clip need be used.

Fig. 9 is a horizontal sectional view taken along the line 9-9 in Fig. 8.

Fig. 10 is a view of a portion of one side of the folded ladder, with the successive rungs spaced apart from each other a short distance to show how the folding is accomplished.

Ladders embodying the present invention are assembled from four basic elements: (1) flexible stiles A, (one pair for each ladder), (2) rungs B, (3) the novel handgrasp and rung-supporting stirrups C, (a pair for each rung B), and (4) locking means D (one each for each place broken rungs and smashed ears if the ladders are damaged, though the construction of the latter reduces the likelihood of such damage. For the first time a pilots ladder can be a maintainable part of a ships equipment without any sacrifice of safety and without having to carry special tools or any special parts except a few extra stirrups.

One important object, therefore, of my invention is to provide a flexible-stile ladder having a novel form of handgrasp stirrup that joins the stiles and the rungs in a novel manner.

Another object of the invention is to provide a pilots ladder than is easily folded for storage and, when folded, is quite compact.

A further object is to provide a less expensive ladder that is superior to the more expensive ones now being used.

Another object is to provide an easily assembled pilots ladder, having fewer parts than such ladders have had heretofore and with those parts easier to assemble than heretofore.

ear 12).

The ladder shown in Figs. 1-3 is assembled from the following elements, illustrating the basic approach. (1) flexible chain stiles 10, (one pair for each ladder), (2) rungs 11, (3) spacing, rung-supporting handgrasp and lashing-ring frames or stirrups 12, (a pair for each rung 11), and (4) locking bolts 13 with nuts 14, (one each for each ear 12). In addition this form of the invention (but not all forms) uses aligning clips 15, (two each for each car 12). There may also be terminal connections, such as round lashing rings 60.

Chains are usually considered to be safer than cables or wire or fibre ropes. The Coast Guard specifications currently call for weldlcss flexible steel chains 10 of the type known as single-loop, weldless, lock-link pattern; so that form of chain is the one chosen for illustration here, and the model shown in Fig. 4 has been awarded US. Coast Guard Approval #l60.0l7/23/0. Each link 16 has at its upper end a single locking loop 17 joining it to the bottom bar 18 of the next link 16 above. Thus the bottom bar 18 is pivotally attached to the locklink loop 17; so the chain 10 folds easily and compactly when the links are turned around these pivots. My in vention calls for supporting the rungs 11 and cars 12 a relative to the chainsltl so that the laddercan be folded tightly (i.e., to the right or left in Fig. 2) without impairing its ability to unfold.

For economic reasons, each rung 11 preferably comprises a pair of members, such as a pair .of rectangular wooden boards 20, 21 of any satisfactory type, specially prepared only bydrilling one bolt hole 22 through each end portion (see Fig. 4). Or each rung 11 may comprise a pair of hollow rectangular metal tubes 23, 24 similarly drilled at 25 and preferably made from lightweight metal, such as an aluminum alloy (see Figs. 1- 3). In either event, the rungs 11 may be made from the simplest standard materials, no special processing being required beyond the bolt opening 22 or 25. In placeof a pair of rung members, the rung 11 shown in Fig. 7 may be used instead; slots 11 at each end serving to receive the stirrups C. The rung 11* may be solid, as shown, or may be hollow or have an opening through it, as in Patent No. 2,638,260 for the sake of light .Weight.

The handgrasp stirrups C not only support the rungs -B on the chains A but also space the ladder stiles A away from the sides of the ship and provide safe hand holds. They also serve as lashing rings when a shorter ladder is needed. Preferably, each hand-hold stirrups C is made from a single strip of metal, such as steel or a strong aluminum alloy, bent to shape. Each handhold stirrup C may be described as generally D-shaped but with a split base recurved on both sides. Or it may be described as an inverted U with added base members. An important thing is that substantially all the stirrup C lies above (or below) the rung 13, instead of being centered with respect thereto, as in the prior art. Another important thing is that the central portion of the stirrup C passes through the flexible stile A, and that the rungs B and stirrup C are secured together and to the stile A by a single means D.

Each handgrasp stirrup 12 (see Figs. 3 and 4) has a pair of parallel vertical side portions 30, 31, either one of which is adaptedto lie flat against the side of a ship. At the upper ends of the portions 30, 31 are converging portions 32, 33 extending upwardly and inwardly to a generally horizontal top portion 34. In place of the angular construction shown, the portions 32, 33 and 34 may comprise an are or curve, but it is highly preferable that the top portion 34 be fiat. Notches 35, 35 in the top portion 34 provide for engagement of the stile A (i.e., the side bars 26, 27 of a chain link 16), the metal strip from which the ear 12 is made preferably being substantially the same width as the chain links 16. The stirrup C is easily fed into the stile A (at a chain link 16 or rope opening 71) from either end thereof. The notches 35 provide only a sliding engagement with the stile A, to permit a slight relative movement therebetween. Note that a chain stile 10, for example, is thereby aligned with its pivots 18 at right angles to the plane of the stirrup 12 to provide for rotation of the locking loops 17 when the latter is folded up for storage.

At the lower end of each stirrup or ear 12 are inwardly extending base portions 36, 37 that terminate at their inner ends in short downwardly extending inner rims 38, 39 which, in turn, may lead to outwardly extending flanges 40, 41 (Fig. 4) or 42, 43 (Fig. 3). When wooden rungs B are used (Fig. 4), longer flanges 40, 41 may be provided in the stirrup 12*, extending about two-thirds or more of the width of the boards 21 21, while shorter flanges 42, 43 may be used with the metal rungs 23, 24.

The flanges 40, 41, 42, 43 are safety features and are not always required; therefore, in the stirrup 12 shown in Fig. 6, they are omitted, the stirrup 12 being identical to the ring 12 except for the omission of these bottom flanges 42, 43. The through bolt 13 is itself able to support the weight required on the step and to maintain the necessary rigidity.

The heights of the portions 38, 39 are preferably matched to the thicknesses of the rung panels 20, 21 or 23, 24, to provide a snug fit of these in the channel provided by the portions 36, 38, 4t) and 37, 39, 41, while the length of the upper base portions 36, 37 are approximately the same as the width of the rung panels. The vertical rim portions 38, 39 are drilled to provide boltreceiving openings 44, 45 through which the bolt 13 extends.

The bolt 13 also passes through a chain link 16 and through holes 22 or 25 in the rung members. The transverse disposition of the bolt 13 through the chain 10 is another important feature of the invention. It makes possible the direct attachment of-each ear 12 to the chain 10 and to both its rung members 20, 21 or 23, 24 by a single bolt, thereby giving increased strength while saving on materials and assembly time. The nut 14, like the bolt head, may lie in the channel 23 of the metal rung members '23, 24 hearing against the inner walls 29 (Fig. 3). With wooden rungs 20, 21 the bolt head and nut 14 bear against the outside surfaces of the rung 11 (Fig. 4). Instead of a bolt and nut a rivet 13 may be used as shown in Fig. 7. If replacement aboard ship is necessary, the rivet 13 may be sawed off, and a bolt 13 may be used to replace it if a rivet 13 is not available. In any event, only a single fastening means is required.

Alignment of the bolt 13 in the chain link 16 and the spacing and bearing of the ear rims 38, 39 is obtained in the forms of the invention shown in Figs. l6 by suitable clip means, such as a-pair of clips 15. Each clip 15 has a washer-like body 51) with a vertical opening 51 that receives the bolt 14, and permits relatively little clearance. A pair of clip members 52 extend from each edge on one side of each body 50 and, with the portions 52 of the other clip 15, embrace the link 16 and hold the clip 15 in alignment therewith. A pair of spacer arms 53 extend in the opposite direction, and their outer ends 54 engage the rims 38, 39 of the ear 12, providing a bearing surface thereagainst.

The fewness of the different parts and the relative simplicity of the manufacturing procedures needed to produce them result in low manufacturing costs. Assembly from the parts shown in Figs. 1-7 is easily done. The clips 15 are located and secured to chain link 16 at predetermined intervals. The stirrups 12 are inserted from one open end into a chain link 16 lying at specified number of links higher than the clips 15, or the clips may 'be put on after the cars 12 and in alignment with them. The ears 12 are worked around through the link 16 by simply turning car 12 90 from its plane until the notches 35 can be engaged in the link. Engagement of the notches 35 with the proper chain link 16 also helps in aligning the openings 44, 45 with the clip openings 51.

' The rungs 11 or 11 are then in place between the portions 36, 38, 40 and 37, 39, 41 of the ears 12. The bolt 13 may then be inserted and the nut 14 screwed on and tightened into place.

The clip 15 may be omitted by using the stirrup 112 of Fig. 8. Here, the vertical portions and 131 are longer than the corresponding portions 33 and 31 in the stirrup 12. Flanges 136 and 137 extend inwardly from the lower end of the vertical portions 130 and 131, and the rungs 11 rest on them instead of beneath them. Location of the rungs 11 in the-stirrup 112 may be provided by short upwardly-extending portions 138. 139 which are provided with bolt-receiving openings 144 and 145. Above the openings 144 and 145, narrowed tongue portions 151, 152 extend across on opposite sides of the chain 10; at least one of them engagingv the opposite rung 11 or portion 133 or 139 to serve as spacing members. Assembly of the ladder of Fig. 8 is done by first threading a stirrup 112 through a chain link 16, then inserting the rungs 11 in the stirrup 112, and then inserting the rivet 13 (or a bolt 13) through the rung 11, stirrup opening 145, chain link 16, stirrup opening 144 and other rung 11. Then the rivet end 13 is closed over to lock it in place. Again, one side (e.g., 131) of the stirrup 112 serves as a spacer from the side of a ship, while the other side (e.g., 130) serves as a handgrasp, just as in the stirrup 12.

Obviously, this invention makes it easy to adjust the distance between steps, by securing the stirrup 12 to different links of a chain at any desired spacing.

When the ladder is in place on a ship, the upper ends of the chain may be anchored by lashing rings 60 or, especially when the ladder is to be shortened, a stirrup 12 may be used as a latching ring. In fact, special lashing rings 60 need not "be used at all. When the ladder hangs down, the handgrasp-lashing rings 12 hold the chain away from direct contact with the ships sides and afford hand holds, so that the ladder is easily ascended and descended. The ladder can be folded tightly into a small bundle, as shown in Fig. 10. When let down, the ladder will unfold readily without placing undue stress on the chain 10.

Fig. 10 illustrates how the ladder folds. A forty-foot ladder may be folded into a box only forty-two inches long. Fig.10 has the successive stirrups moved somewhat apart, to show the path of the chain better. Reading from right to left in Fig. 10, it will be seen that the chain 10 enters the stirrup 12 from the upper left, which is the bottom of the stirrup, and goes up to the notched portion 34. From there a chain portion 10 goes to the bottom of the next stirrup 12*, which is reversed and to one side of the first stirrup. From its upper end, a chain portion 10 goes to the third stirrup 12*, set side by side with the first stirrup. The chain portion 10 leads from the top of the third stirrup to the bottom of the fourth stirrup, which is beside and in line with the second stirrup and, like it, inverted with respect to the first and third stirrups. This process continues to a desired length and then a second bank may be formed.

The ladder is protected from damage by this construction, as shown; yet if any of the ladder rungs 11 are damaged, they can readily be replaced, no tools being necessary except the ones normally at hand for bolting the rungs in place.

To those skilled in the art to which this invention relates, many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the spirit and scope of the invention. The disclosures and the description herein are purely illustrative and are not intended to be in any sense limiting.

I claim:

1. A pilots ladder or the like including in combination a pair of lock-link chain stiles, each link having a bar portion at one end pivoted in a locking loop of the succeeding link; a plurality of stirrups secured to each stile, each stirrup having a pair of parallel vertical side portions, an upper end portion joining said 'vertical portions at the top and provided with a pair of slots in opposite edges engaging side members of a chain link, a pair of base portions extending in toward each other from the lower ends of the vertical portions, a pair of vertically depending portions extending down from the inner ends of said base portions, and a pair of outwardly-turned flanges extending out from the lower end of said depending portions; a series of pairs of narrow tread members supported at opposite ends by said stirrups, each nested in the three-sided support provided by said base portions, said depending portions, and said outwardly-turned flanges; clip means each secured to a chain link and having a bolt opening therethrough and spacing arms bearing against said depending portions; and bolts each extending through one end of a pair of said tread members, both said depending portions, a said clip means, and a link of said chain.

2. A pilots ladder or the like including in combination a pair of chain stiles with a plurality of links; a plurality of stirrups secured to each stile, each stirrup having a pair of generally parallel vertical side portions, an upper end portion joining said vertical portions at the top and provided with a pair of slots in opposite edges engaging opposite sides of a chain link, a pair of base portions extending in toward each other from the lower ends of the vertical portions, and a pair of vertical portions extending from the inner ends of said base portions; a series of tread members supported at opposite ends by said stirrups, each nested against said base portions and said vertical portions; spacing means engaging a chain link and spacing said vertical portions from each other; and bolts each extending horizontally crosswise of said tread members through one end of said tread members, both said vertical portions, and a link of said chain.

3. The ladder of claim 2 wherein said spacing means comprises clip means secured to a chain link and having a bolt opening for said bolt therethrough and a pair of spacing arms bearing against said vertical portions.

4. The ladder of claim 2 wherein said spacing means comprises a narrowed tongue extending from each said base portion toward the other said base portion, through a chain link and against the vertical portion of said other base portion.

5. The ladder of claim 2 wherein the portions of said tread members secured to said stirrups lie below said base portions and against the lower surface thereof and against and on outer surfaces of said vertical portions.

6. The ladder of claim 2 wherein the portions of said tread members secured to said stirrups lie above and upon said base portions and against said vertical portions.

7. A pilots ladder or the like including in combination a pair of lock-link chain stiles with a plurality of links; a plurality of unitary stirrups secured to each stile, each stirrup being a single integral piece having a pair of parallel vertical side portions, an upper end portion joining said vertical portions at the top and provided with a pair of slots in opposite edges engaging the vertical sides of a chain link, and a pair of base portions extending in toward each other from the lower ends of the vertical portions, each with a pair of vertical portions extending from the inner ends of said base portions; a series of narrow tread members supported at opposite ends by said stirrups and nested against said base portions and said vertical portions; means spacing said vertical portions apart on opposite sides of a chain link; and a single bolt at each stirrup extending through said tread members, both said vertical portions, and a link of said chain.

8. A hand grasp stirrup for a pilots ladder or the like, having a pair of lock-link chain stiles, a plurality of said stirrups secured to each stile, a series of pairs of narrow tread members supported at opposite ends by said stirrups, and bolts each extending through one end of a pair of said tread members, two depending portions of said stirrup, and a link of said chain, each said stirrup comprising a pair of parallel vertical side portions, an upper end portion joining said vertical portions at the top and provided with a pair of slots in opposite edges for engaging side members of a chain link, a pair of base portions extending in toward each other from the lower ends of the vertical portions, a pair of vertically depending portions extending down from the inner ends of said base portions and through which said bolt extends, and a pair of outwardly-turned flanges extending out from the lower end of said depending portions; said stirrup providing a pair of three-sided supports each comprising a said base portion, a said depending portion, and a said outwardly-turned flange in which a said tread member is nested.

References Cited in the file of this patent UNITED STATES PATENTS 287,560 Miller Oct. 30, 1883 1,117,211 Mayes Nov. 17, 1914 2,638,260 Skolmen May 12, 1953

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