US3741340A - Flexible ladder - Google Patents

Abstract

Loops are formed at correspondingly spaced levels in two flexible fabric tapes. The two loops at each level receive the opposite ends of a ladder rung. The ladder is provided with a top rung that prevents lateral separation of the tapes to prevent disconnection of the rungs from the tape during use of the ladder. The tapes are provided with means at the upper ends for securing the ladder to the inner side of a building exterior wall on opposite sides of a window. Means may be provided on the lower end of the ladder for securing another ladder section thereto, with ladder side separation preventing means.

Description

United States Patent 1191 Andrews June 26, 1973 FLEXIBLE LADDER 188,546 3/1964 Sweden 182/196 [76] Inventor: William L. Andrews, 1 S. Ridge Road, Richmond, Va. 23229 Primary Exqmin er -Reinaldo P. Machado All I [22] Filed: Nov. 18, 1971 orney John W Malley, Edward M Prmce et al [211 App]. No.: 199,919

[57] ABSTRACT [52] US. Cl. 182/196 L p r orme t correspon ingly spaced levels in [51] Int. Cl. E06c 1/56 two fl le fabric ape The wo loops at each level [58] Field of Search 182/196, 197, 198, receive the pp ends of a ladder s- The ladder 132/199, 57 is provided with a top rung that prevents lateral separation of the tapes to prevent disconnection of the rungs [56] References Cited i from the tape during use of the ladder. The tapes are UNITED STATES PATI'ENTS provided with means at the upper ends for securing the ladder to the inner side of a building exterior wall on 3 5:33 at opposite sides of a window. Means may he provided on 1242286 10/1917 182/196 the lower end of the ladder for securing another ladder 1I275I0s3 8/1918 Leiding 182 57 Section them with ladder Side separation Preventing FOREIGN PATENTS 0R APPLICATIONS means 117,319 9/1946 Sweden 182/197 14 Claims, 5 Drawing Figures PATENTEDJUNZS lsza 3.741.340

INVENTOR /mzaa oln FLEXIBLE LADDER BACKGROUND OF THE INVENTION Flexible ladders have many uses; one principal one is for normally stored, emergency use, e.g. to escape during a fire or other emergency from an upper story of a building which does not have a fire escape or an exit available to an occupant of the building.

A typical known device is shown at the lower right on page 45 of the Hammacher-Schlemmer Summer, 1970 catalog.

Other flexible ladders are shown in the following United States patents:

Everitt' 197,927 Borgfeldt 294,360 Fiegenbaum 314,287 Kimball et al 458,023 Wright 686,182 Marryatt 2,985,254 Rabelos 3,294,196 Green 3,307,654

Clearly, a normally stored ladder should be as compact and inexpensive as is possible, consistent with its being structurally sound for its intended use.

During emergencies, it is well-known that many people do not think as rationally as they otherwise would, so ladders for emergency use should also be easy to use as intended, and difficult to use as unintended;

one of the difficulties inherent in escaping through an upper story window during an emergency is, for most people, that they have had little experience climbing out windows under any circumstances. Accordingly, one important characteristic of a ladder for emergency use, is that it be as inviting to use as possible, especially near its upper end, where the user will have his first and most danger-filled experience with the device.

Prior art devices all appear to be somewhat deficient in at least-one of the above-enumerated desired qualities.

SUMMARY OF THE INVENTION Loops are formed at correspondingly spaced levels in two flexible fabric tapes. The two loops at each level ladder to the inner side of a building exterior wall on opposite sides of a window. Means may be provided on the lower end of the ladder for securing another ladder section thereto, with ladder side separation preventing means.

By preference, the sides of the ladder are made of woven synthetic plastic fabric tape, e.g. the kind of nylon tape used in the fabrication of automotive and aircraft passenger safety belts. In the preferred embodiment, the tape is periodically doubled back upon itself twice in succession to create a loop and sewed together at the base of the loop to provide the rung receiving loops. The sewing also proceeds through the tape above each loop to structurally integrate the loop with the remainder of the tape and to make the securement less subject to failure.

The top-most rung, and in some instances the bottom rung, differs from the remainder of the rungs in one preferred embodiment by consisting of a strong metal bar having integral eyes at each end which hold the ladder sides a fixed distance apart.

Above that rung, the ladder sides may safely diverge for attachment to the building wall, e.g. about one-third of the way up the'window on opposite sides of the window, on the inside of the building, to provide convenient and reassuring hand holds for the persons using the ladder.

The principles of the invention will be further hereinafter discussed with reference to the drawing wherein a preferred embodiment is shown. The specifics illustrated in the drawing are intended to exemplify, rather than limit, aspects of the invention as defined in the claims.

BRIEF DESCRIPTION OF THE DRAWING FIG. I is a perspective view from inside the building after the ladder has been deployed. Note that the ladder sides and first rung are reassuringly in view of the user in this preferred embodiment.

. FIG. 2 is a perspective view of the same installation as seen from outside the building;

FIG. 3 is a perspective view of the top rung illustrated in FIGS. 1 and 2;

FIG. 4 is a fragmentary perspective view, partly in section, of one rung end received in a ladder side loop; and

FIG. 5 is an enlarged fragmentary top plan view of modified mounting for the ladder.

DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENT By preference, the flexible ladder 10 includes two sides 12 made of flexible tapes having integrally fabricated loops 14 at correspondingly spaced levels to receive the opposite ends of rungs 16. The top rung 1'8 (and in the instance depicted, the bottomrung 20 are metal bars 21 having integral eyes 24 at each end for securement to the sides 16 to prevent lateral spreading thereof. Above the rung 18, the sides diverge and terminate in securing means 20 for securing the ladder to complementary securement devices 22 provided on the I interior of the wall of the building bordering both sides of the window.

As mentioned above, the sides 12 are preferably constituted by tape, webbing or ribbon (these terms being used synonymously herein) of the same kind as is used to make automotive and aircraft seat belting. Nylon is a typical and preferredcomposition for the sides 12, but polyethylene, polypropylene and blends including other fibers could be used.

The loops 14 are each formed by doubling the webbing back upon itself twice, e.g. at 26, 28, to create a loop, then sewing the two opposite parts 30, 32 of the base of the loop to one another and to the webbing subjacent the first doubling 26 (proceeding from the bottom of the particular side). This provides an integrated structure having a much lower tendency to come apart than would a joint created by sewing together only the two opposite parts 30, 32 of the base. The term sewing is used generically to include fastening-together with a filamentary material which passes through the webbing, stapling, riveting and equivalent means.

The rungs 16 are preferably made of wood because of its good strength and non-slip characteristics and its low cost. As shown, the rungs are cylindrical and each have a circumferential,outwardly opening groove 34 in the outer peripheral surface thereof adjacent each end. thereof.

The grooves 34 receive the loops 14 to retain the rungs in place as shown. The loops 14 may be fabricated by wrapping the webbing about the bases 36 of the respective grooves 34 in order to lock the rungs in place against withdrawal, or the loops may be fabricated so as to have so small a size that a rung, if forced,

can be slid into place in the groove as shown.

The upper ends of the sides 12 are doubledover and straps has a loop 46 created therein at the lower end thereof for securing the straps 44 to the eyes 24.

The upper ends of the straps 44 are provided with fixtures 20 such as clip rings.

In a typical installation, eye bolts 22 or the like would be installed in the building walls beside the intended exit window. Although in some cases these bolts may be firmly secured to the window casement itself, there are many old buildings where this would be an unsafe practice since the weightof a descending person could pull out the window casement. However, where that is not a problem, the devices 22 could alternatively be installed on the window casement itself, eg. at 22'. Thestraps 44 are each at least a foot long, so, as

shown, the devices22 are installed at least a foot above the window sill. By preference, when the flexible ladder is deployed as shown, the top rung 18 is visible to the prospective user from within the building. This means that asthe user crawls out the window and onto the ladder 10, he has the straps 44 and the top rung immediately and reassuringly available as hand holds.

In certain high risk situations, it might be desirable to keep the ladder l hooked to the building at 22 at all times, with the bulk of the ladder disposed on the floor adjacent the window ready to be droppedout the window when needed. Generally, however, the devices 22 would be preinstalled and the remainder of the ladder l0 stored at hand, after it has been connected at 22 and deployed a few times by its potential users as a drill.

It should now be noticed that the lower ends of the sides 12 may be provided with sewn end loops 50 which 0 I are secured through eyes 24 of a bottom rung 20' similar to the metal bar 21. This permits the ladder to be adapted for use with buildings having floors of nonstandard height through the addition of further flexible I ladder sections like the one depicted which would be fastened to the bottom rung 20 through clip rings similar to those shown at 20. Typically, the distance between the top and bottom rungs may be about 10-20 feet.

The mounting of the ladder as shown is a preferred one. However, other mountings are possible, albeit less preferred. For instance, the devices 22 could be installed on the floor of the building adjacent the window sill or in the wall of the building below thewindow sill or above the window.

The modification shown in FIG. 5 is an enlarged frag-' mentary view showing one-half of the mounting device 50, the other half being identical. The mounting device 50 comprises a horizontal bar 152 installed in the window jam using opposed C-clamps 54 which are adjustably secured to the bar via set screws 56to varythe distance therebetween and which are adjustable via simit the bar 52 lie inside the building, against theinterior M lar set screws58 to accommodate securement in window jams of varied thickness. The opposite ends 60 of face of the window jam. and/or wall. Between the opposed C-clamps 54, the bar mounts two laterally spaced eyes 62 to which the .clip rings 20 at the upper ends of the ladder straps 44 are secured.

Preferably, the eyes 62 are canted upwardly relative to horizontal, so that when the bar 52 is disposed upon a window sill, there is still spade to accommodate the attachment of the clip rings 20. I

The bar 52 and its clamps 54 maybe preadjusted to fit a particular window, then permanently secured with respect to one another and the clamps adjusted and secured with respect to the window thickness. Then, the

bar assembly may be left in place, where feasible, with a the ladder being left tobe attached when it is to be i used, or the bar assemblymay be tipped generally diag- I onally in the window opening to remove it. Then the ladder may be secured via clips 20 to the bar assembly andthis unit stored near the window ready to be used. When this unit is to be used in such fashion, the window is opened, the bar assembly (with the ladder attached) inserted diagonallyin the frame, lowered to the hori zontal, secured in the position depicted, and the ladder permittedto hang down drom the bar assembly for immediate use. I

The remainder of the ladder may beas depicted in FIGS. 1-4.

It should now be apparent that the flexible ladder as described hereinabove possesses each of the attributes set'forth in the specification under the heading Sum 7 mary of the Invention" hereinbefore. Because the flexible ladder of the invention can be modified to some extent without departing from the principles of the invention as they have been outlined and explained in this specification, the present invention should be understood as encompassing all such modifications within the spirit and scopeof the following claims.

What is claimed is: 1. A flexible ladder comprising: an inextensible top rung bar h ring at each end thereof;

two elongated,flexible ladder sides each having an I upper endsecured to'a respective one of said rings;

a plurality of ladder rungs extending laterally between the two ladder sides at vertically spaced in-.

'tervals; a 1 i means securing the ladder rungsto the respective ladder sides adjacent the ends of the rungs;

two strap means having lower ends thereof secured to respective top rung ring means, extending upwardly therefrom and eachterminating in securing means for securing the flexible ladder to a fixed structure from which the ladder is to depend;

the ladder sides being fabricated of fabric webbing which is continuous from said top rung bar rings to' the lower end of the ladder;

each ladder side in a plurality of corresponding instanceshaving the webbing thereof doubled over upon itself twice in close succession to define a loop for each such occurrencerand as are aving means defining a means securing the two sides of the base of each loop to one another and to the webbing of the respective ladder side immediately below the first of the doubling overs of the respective loop, as counted from the lower end of the respective ladder side. 2. The ladder of claim 1 wherein the securing means of the straps comprises:

two anchor means configured for fixed mounting onthe structure from which the ladder is to depend;

and

a clip device on each strap for disconnectably clipping the straps to the respective anchors.

3. The ladder of claim 2 wherein the anchor means are disposed substantially further apart than the ladder sides so the anchor means may be installed in a building wall on opposite sides of a building window, inside the building for facilitating deployment of the ladder out the window.

4. The ladder of claim 1 wherein in respect to said plurality of ladder rungs, each rung is a wooden bar having means defining a circumferentially extending, radially outwardly opening .groove therein adjacent eachend thereof; each ladder sideloop being received in a respective one of said grooves in order to provide said means securing the ladder rungs to the respective ladder sides.

5. A flexible ladder comprising:

two elongated, parallel, flexible ladder sides spaced apart from each other;

a plurality of ladder rungs extending laterally between the two ladder sides at vertically spaced intervals; v

each flexible ladder side being continuous and in a plurality of corresponding occurrences being doubled over upon itself twice in close succession to define a loop for each such occurrence, each loop receiving the end of a ladder rung; and

means securing the two sides of the base of each loop to one another and to the webbing of the respective ladder side immediately below thefirst of the doubling overs of the respective loop, as counted from the lower end of the respective ladder side.

6. The ladder of Claim 5 wherein the anchor means for securing the flexible ladder to a-fixed structure is configured to mount against the inside of a building wall adjacent the sill of a window frame, this securing means comprising a bar that is longer than the window with which it is to be associated is wide, so that the opposite ends of the bar may abut the inside of the building wall on the respective sides of the window; a pair of eyes secured on the bar intermediate the ends of the bar with closer spacing than the width of the window with which the bar is to be associated; and radially projecting guide means, one secured on the bar between each eye and each bar end to grasp the window frame to prevent lateral movement of the bar; and hook means on the upper ends of the ladder sides, said hook means being secured to respective of said eyes.

7. The ladder of claim 6 wherein the radially projecting guide means are constituted by two C-clamps which open toward the respectively adjacent ends of the bar, said C-clamps being thickness-adjustable'to prevent the bar from falling back into the building when there is no net force pulling the bar forwardly.

8. The ladder of claim 7 wherein said C-clamps are secured on said bar by adjustment means which are operable for adjusting the spacing between the two C- clamps to accommodate the securing means to window frames of differing width.

9. The ladder of claim 9 wherein said eyes are canted upward from horizontally to'provide clearance for the hook means when the bar rests on a window sill.

10. The ladder of claim 5 wherein in respect to said plurality of ladder rungs, each rung has means defining a circumferentially extending, radially outwardly opening groove therein adjacent each end thereof; each ladder side loop being received in a respective one of said grooves in order to provide said means securing the ladderrungs to the respective ladder sides.

11. The-ladder"of claim 5 additionally comprising:

anchor means configured for fixed mounting on the structure from which the ladder is to depend; and

means on each flexible ladder side for securing the ladder side to the anchor means.

12. The ladder of claim 5 further comprising means defining a lower end loop on the lower end of each ladder side; and an inextensible bottom rung bar having means defining a ring at each end thereof, each ring receiving and having secured therethrough a respective one of said lower'end loops. v

13. The ladder of claim 5 wherein the bottom rung bar and the rings thereof are integrally formed of metal.

14. The ladder of claim 5 wherein the ladder sides are fabricated of fabric webbing.

. l l l

Claims (14)

1. A flexible ladder comprising: an inextensible top rung bar having means defining a ring at each end thereof; two elongated, flexible ladder sides each having an upper end secured to a respective one of said rings; a plurality of ladder rungs extending laterally between the two ladder sides at vertically spaced intervals; means securing the ladder rungs to the respective ladder sides adjacent the ends of the rungs; two strap means having lower ends thereof secured to respective top rung ring means, extending upwardly therefrom and each terminating in securing means for securing the flexible ladder to a fixed structure from which the ladder is to depend; the ladder sides being fabricated of fabric webbing which is continuous from said top rung bar rings to the lower end of the ladder; each ladder side in a plurality of corresponding instances having the webbing thereof doubled over upon itself twice in close succession to define a loop for each such occurrence; and means securing the two sides of the base of each loop to one another and to the webbing of the respective ladder side immediately below the first of the doubling overs of the respective loop, as counted from the lower end of the respective ladder side.

2. The ladder of claim 1 wherein the securing means of the straps comprises: two anchor means configured for fixed mounting on the structure from which the ladder is to depend; and a clip device on each strap for disconnectably clipping the straps to the respective anchors.

3. The ladder of claim 2 wherein the anchor means are disposed substantially further apart than the ladder sides so the anchor means may be installed in a building wall on opposite sides of a building window, inside the building for facilitating deployment of the ladder out the window.

4. The ladder of claim 1 wherein in respect to said plurality of ladder rungs, each rung is a wooden bar having means defining a circumferentially extending, radially outwardly opening groove therein adjacent each end thereof; each ladder side loop being received in a respective one of said grooves in order to provide said means securing the ladder rungs to the respective ladder sides.

5. A flexible ladder comprising: two elongated, parallel, flexible ladder sides spaced apart from each other; a plurality of ladder rungs extending laterally between the two ladder sides at vertically spaced intervals; each flexible ladder side being continuous and in a plurality of corresponding occurrences being doubled over upon itself twice in close succession to define a loop for each such occurrence, each loop receiving the end of a ladder rung; and means securing the two sides of the base of each loop to one another and to the webbing of the respective ladder side immediately below the first of the doubling overs of the respective loop, as counted from The lower end of the respective ladder side.

6. The ladder of Claim 5 wherein the anchor means for securing the flexible ladder to a fixed structure is configured to mount against the inside of a building wall adjacent the sill of a window frame, this securing means comprising a bar that is longer than the window with which it is to be associated is wide, so that the opposite ends of the bar may abut the inside of the building wall on the respective sides of the window; a pair of eyes secured on the bar intermediate the ends of the bar with closer spacing than the width of the window with which the bar is to be associated; and radially projecting guide means, one secured on the bar between each eye and each bar end to grasp the window frame to prevent lateral movement of the bar; and hook means on the upper ends of the ladder sides, said hook means being secured to respective of said eyes.

7. The ladder of claim 6 wherein the radially projecting guide means are constituted by two C-clamps which open toward the respectively adjacent ends of the bar, said C-clamps being thickness-adjustable to prevent the bar from falling back into the building when there is no net force pulling the bar forwardly.

8. The ladder of claim 7 wherein said C-clamps are secured on said bar by adjustment means which are operable for adjusting the spacing between the two C-clamps to accommodate the securing means to window frames of differing width.

9. The ladder of claim 9 wherein said eyes are canted upward from horizontally to provide clearance for the hook means when the bar rests on a window sill.

10. The ladder of claim 5 wherein in respect to said plurality of ladder rungs, each rung has means defining a circumferentially extending, radially outwardly opening groove therein adjacent each end thereof; each ladder side loop being received in a respective one of said grooves in order to provide said means securing the ladder rungs to the respective ladder sides.

11. The ladder of claim 5 additionally comprising: anchor means configured for fixed mounting on the structure from which the ladder is to depend; and means on each flexible ladder side for securing the ladder side to the anchor means.

12. The ladder of claim 5 further comprising means defining a lower end loop on the lower end of each ladder side; and an inextensible bottom rung bar having means defining a ring at each end thereof, each ring receiving and having secured therethrough a respective one of said lower end loops.

13. The ladder of claim 5 wherein the bottom rung bar and the rings thereof are integrally formed of metal.

14. The ladder of claim 5 wherein the ladder sides are fabricated of fabric webbing.

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