US3907064A

US3907064A - Extendable escape ladder

Info

Publication number: US3907064A
Application number: US412410A
Authority: US
Inventors: Hans Erik Svalberg; Erik Arnold Svalberg
Original assignee: Individual
Current assignee: Individual
Priority date: 1973-11-02
Filing date: 1973-11-02
Publication date: 1975-09-23
Anticipated expiration: 1992-09-23

Abstract

The object of the invention is a ladder with flexible side members and rungs or steps extended between them. It is extendable as a result of the side members being at their upper ends provided with securing devices for the ladder. The securing devices are connected with a magazine which can be opened and in which the rungs or steps are kept collected in order sequence during the inactive state of the ladder, and out of which they are able, as a result of their own weight and that of the side members, to fall freely when the magazine is open.

Description

United States Patent [191 Svalberg et al.

[ Sept. 23, 1975 Burt 182/70 Staraniclk 182/70 [57] ABSTRACT The object of the invention is a ladder with flexible side members and rungs or steps extended between them. It is extendable as a result of the side members being at their upper ends provided with securing devices for the ladder. The securing devices are connected with a magazine which can be openedv and in which the rungs or steps are: kept collected in order sequence during the inactive state of the ladder, and out of which they are able, as a result of their own weight and that of the side members, to fall freely when the magazine is open.

5 Claims, 4 Drawing Figures US Patent Sept. 23,1975 Sheet 1 of2 3,907,064

i a l US Pat6nt Sept. 23,1975 Sheet 2 of2 3,907,064

11 FIG.3

EXTENDABLE ESCAPE LADDER The increasingly frequent fires caused either by faults and deficiencies in electrical installations and devices, in fireplaces etc., or by negligence or carelessness, have created an increasing demand for a safe evacuation method.

The various types of ladders, rope ladders and others, that are available on the market, have not met with the acceptance of the general public to an extent corre sponding to the actually existing evacuation demand. As far as detached houses and blocks of flats are concerned owners do not for various reasons have fixed ladders attached to walls. Fixed ladders are also expensive, i.a. because they require a certain maintenance, and in many cases several fixed ladders are needed to provide alternative evacuation possibilities. The rope ladders and, to a greater extent, twin lines with girdle, which are mainly to be found in hotels and apartments, are difficult to use for children as well as women and old people and therefore have not been adopted to any mentionable extent for use elsewhere.

The object of the present invention is a ladder so devised that it constitutes a satisfactory solution of the evacuation problem at fires. This ladder is maintenance-free and of a design simplifying manufacture and, at the same time, requires so little space that it can be kept easily available, e.g. in corridors, in hotel rooms, in detached houses and in general in houses where evacuation can be effected by means of ladders of reasonable length. Moreover, it is so easy to rig up and to use that it can be utilized both by children and by old people. I

Setting out from the premise that such a ladder is to have flexible side members with rungs or steps between them, it is proposed according to the invention, in order to achieve this purpose, that this ladder is to be extendable due to the fact that the side members are, at their upper ends, provided with attachment organs for the ladder which are connected with a magazine which can be opened and in which the rungs or steps are kept collected in order sequence during the inactive state of the ladder, and from which they can, due to the weight of themselves and of the sides, fall out freely when the magazine is open. Because the rungs are kept collected in a special magazine with the flexible side members folded up, such a ladder will be of a size so small that it can readily be kept even in a room, at the same time that it can very easily be made ready for use simply by letting the rungs fall out of the magazine, the side members, which may for instance consist of chains, extending so that the ladder is ready for use practically immediately after having been rigged up in a window or the like.

When of a design which has in practical tests proved to be particularly favourable, the magazine consists in principle of two parallel U-sections the legs of which are turned towards each other, gripping over the ends of the rungs or steps in a manner to constitute guides for the latter. With this magazine design a ladder according to the invention is simple and inexpensive to manufacture, at the same time permitting easy checking that the rungs are correctly located in the magazine.

The two U-sections can be fixed in their respective positions by means of rigid spacing members extended between them. This also offers the advantage that these spacing members can be used as rungs or steps and thus become part of the ladder itself. This provides the advantage that when using the ladder for evacuation of a house people first step out on the rigid ladder section formed by the magazine, thus experiencing a secure feeling prior to the actual descent the ladder on the part of it suspended under the magazine, completely flexible and reminding of a descent.

For practical reasons it may also be preferable that the upper spacing member forming a rung or a footstep, also constitutes a fixed end-wall in the magazine.

For the attaching or hooking up of a ladder according to the invention e. g. across a window sill, a balcony railing or the like, the magazine should be provided with devices suitable for this purpose. These devices constitute, when the ladder is given a particularly favourable design according to the invention, two clamping yokes attached at either side piece of the magazine, the upper ends of which are shaped as hooks, their lower ends constituting spacing members between the rungs and the wall surface or the like, along which the ladder is suspended when used.

The opening facility in the magazine can preferably consist in the latter being at its lower end provided with at least one device which is adjustable between a position retaining the rungs or steps in the magazine and a position in which the rungs or steps are free to fall out of the magazine.

The invention will be described in more detail in the following with reference to a model design shown on the attached drawings.

FIG. 1 displays a plan view, from the front, of a particularly favourable design of a ladder according to the invention.

FIG. 2 is a section along the line 2-2 in FIG. 1 through this ladder.

FIG. 3 shows how the ladder is rigged up across a window sill and how the rungs fall out of the magazine which is a part of the ladder, whereas FIG. 4 illustrates how the ladder is used.

As is evident from the drawings a ladder according to the invention consists principally of two flexible side members 10 with rungs or steps 11 extended between them. In the design shown here the two side members consist of metal chains but naturally also wires, ropes, bands or the like can be used as flexible side members. In the design shown, the rungs or steps 11 consist of square pipes but can also be of other shape. Through holes drilled inwards from each end of each rung the side members or chains 10 extend to the next rung 11 and are locked inside the rungs by a rod 12 passing through a link in the chain and so devised that the chain cannot slide off it. At their upper ends the side members or chains 10 are provided with devices for the clamping and keeping in position of the ladder e.g. across a window sill (refer to FIGS. 3 and 4). In the design shown, these devices consist of two yokes 13 made e.g. of light-metal piping. The upper ends of these yokes are shaped as hooks 14 whereas their lower ends constitute spacing members 15 between the ladder and the wall surface or the like along which the ladder is suspended when used (see FIG. 4).

The yokes 13 support between them a magazine 16 which can be opened and in which the rungs 11 are, during the inactive state of the ladder, kept assembled in order sequence and wherefrom, when the magazine is open and more or less vertically oriented, they are free to fall as a result of their own weight and that of the chains, causing the ladder to be fully stretched out and ready to be used for its purpose.

In principle, the magazine 16 can, as in the example here consist of two parallel U-sections 17, turned towards each other and attached to the central parts of 5 the yokes 13. The legs of these sections are turned towards each other gripping around the ends of the rungs l1 and constituting guides for them. The two U- sections 17, and thus also the yokes 13, are fixed in their mutual positions by means of

rigid spacing members

18,19, extended between them and functioning as rungs in the ladder.

The magazine 16 may however, be devised in several different ways. Thus, a cam or rail may, instead of the

U-sections

18,19, be devised on each of the sides of the centre parts of the yokes 13 turned towards each other, on which cams or rails the rungs 11 can be slidingly guided by means of slots at their two ends.

The upper 18 of the two

spacing members

18,19 being part of the magazine can preferably consist of a T-section, the one flange 20 of which protrudes in between the two U-sections 17 in a way to form an end wall in the magazine which prevents the rungs kept in order sequence in it from falling out if, for some reason or other, the ladder should be turned upside down. On the other hand, the lower 19 of the two

spacing members

18, 19 may preferably consist of an L-section and support the locking device of the magazine 16 which is adjustable between a position retaining the rungs 11 in the magazine and a position in which the rungs are free to fall out of the magazine. In the design of a ladder according to the invention which is shown here, the locking device consists of a rod 21 extended across the entire length of the magazine, said rod being rotatably suspended in the two

spacing members

18,19. At its upper end the rod or locking device 21 is equipped with a fixedly attached handwheel 22. At its lower end it has a part bent at an angle 23 which is intended to be turned inwards across the opening for the rungs of the magazine when the ladder is stored with the rungs assembled in the magazine, and turned away from this opening with the handwheel 22 when the ladder is to be used and the rungs are to be free to fall out of the magazine. In order to function correctly the locking device is also provided with a helically wound spring 24 applied around the rod 21 between the spacing member 18 and the handwheel 22.

Since a ladder according to the invention can be made entirely of metal, it is both rugged and very light. The weight of the ladder need not exceed 5 kg which makes it easy to handle also for persons of little physical strength. Since the ladder comprises a magazine in which the rungs are stored in order sequence in a collected state, the rungs with the flexible side members do not get intertwined, which is often the case with rope ladders and the like which are freely unfolded.

The yokes 13 together with the magazine 16 and the

spacing members

18,19 which are part of it, enable the person using the ladder, e.g. for evacuation, to get a firm hold and support for both hands and feet in the crucial phase when the actual climbing down along the ladder is to begin. The two spacing members 15 of the yokes are in this connection also of great value, since they permit the hands and feet of the climbing person always to be out of touch with the house wall or other surface behind the ladder. By means of the yokes 13 and the clamping device 14 on the yokes the ladder is firmly secured e.g. around a window sill in a selftightening manner by the weight of the person on the ladder causing the yoke to become still more fixedly secured.

The actual release of the ladder when it has been attached with its yokes across a window sill or the like, is effected by turning the handle or handwheel 22 so that the angular part 23 of the rod 21 is removed from its position blocking the opening of the magazine 16, whereupon the rungs 11 with their chains 10 immediately fall out of the magazine in the way shown in FIG. 3. This process takes place in seconds and because the rungs and their chains have been kept in order sequence in the magazine 16 there is no risk that the ladder would not be immediately ready to be used for its purpose.

In order to facilitate the storing of the ladder in a room e.g. in an apartment the yokes 13 may be in two parts so that their two ends can be rotated in relation to their centre sections and the magazine 16, so that when stored the ladder becomes fairly flat by the spacing members 15 and clamping devices 14 of the yokes being turned inwards towards each other.

The invention is not limited to the embodiment described above and shown in the drawings but can be modified in many different ways within the scope of the claims.

What we claim is:

1. An extendable ladder comprising a pair of flexible .side members, a plurality of rungs extending between said flexible side members, a magazine for said ladder, said magazine comprising two parallel U-sections that open toward each other for slidably receiving the ends of said rungs for storing the ladder in a collapsed condition, a pair of rigid spacing members extending between and interconnecting said U-sections and constituting the top two rungs of the ladder, the upper of said spacing members comprising a fixed end wall closing said magazine, and movable means for selectively opening and closing the other end of the magazine, said movable means being mounted on and extending between said rigid spacing members.

2. A ladder as claimed in claim 1, said movable means comprising retaining means for said rungs movable into and out of the path of said rungs to close and open said magazine, respectively and disposed adjacent the lower of said rigid spacing members and means adjacent said upper spacing member for manipulating said movable means.

3. A ladder as claimed in claim 2, said movable means comprising a rotatable shaft with a detent adjacent said lower rigid spacing member and a handle for rotating said shaft adjacent said upper rigid spacing member.

4. A ladder as claimed in claim 3, said rotatable shaft being slidable on and relative to said rigid spacing members, and spring means acting between one of said rigid spacing members and said shaft to urge said shaft in such a direction that said detent presses yieldably against said rungs.

5. A ladder as claimed in claim 1, and a pair of yokes attached one at each side of said magazine, said yokes having upper ends shaped as hooks to extend over a window sill and lower ends which are spacing members to space the magazine away from a wall beneath a said window sill.

Claims

1. An extendable ladder comprising a pair of flexible side members, a plurality of rungs extending between said flexible side members, a magazine for said ladder, said magazine comprising two parallel U-sections that open toward each other for slidably receiving the ends of said rungs for storing the ladder in a collapsed condition, a pair of rigid spacing members extending between and interconnecting said U-sections and constituting the top two rungs of the ladder, the upper of said spacing members comprising a fixed end wall closing said magazine, and movable means for selectively opening and closing the other end of the magazine, said movable means being mounted on and extending between said rigid spacing members.