WO1992003189A1

WO1992003189A1 - Apparatus for controlling a descent of a person or an object

Info

Publication number: WO1992003189A1
Application number: PCT/GB1991/001430
Authority: WO
Inventors: Ghassan Nehaili
Original assignee: Individual
Current assignee: Individual
Priority date: 1990-08-24
Filing date: 1991-08-23
Publication date: 1992-03-05
Anticipated expiration: 1993-02-24
Also published as: GB9018649D0; AU8440791A

Abstract

Apparatus for controlling a descent of a person or object comprises a tubular lining (1) of flexible material, through which the person or object is intended to pass and which is surrounded along its length by an elastic tube (3), the lining and the tube being connected together along seams (2, 4). The elastic tube (3) forms an openwork structure, preferably comprising elastic sheet material having a plurality of holes (5) to provide the required radial expandability and circumferential elasticity of the elastic tube (3). The elastic tube (3) has a smaller diameter in its unexpanded state than the diameter of the lining (1) so as to constrict the cross-sectional area of the interior of the apparatus.

Description

APPARATUS FOR CONTROLLING A DESCENT OF A PERSON OR AN OBJECT

The present invention relates to apparatus for controlling a descent of a person or an object and in particular, though not exclusively, to such apparatus in the form of an escape chute through which one or more persons can descend safely from, for example, the upper floors of a high building in the event of fire or some other hazard.

One type of escape chute, which is disclosed in British Patent No. 1269401, generally consists of a flexi¬ ble hose, which may itself be elasticated or it may be provided with a plurality of elastic constrictions at spaced intervals along its length in order to prevent free-fall of a person descending within the hose. Such constrictions may be formed by elastic ties or tension springs extending around the outside of the hose which expand as a person passes through the constrictions and then contract after the person has passed.

Escape chutes which are in present use tend to be relatively complex in construction and thus expensive. They can also be cumbersome and generally require consider¬ able storage space. Consequently, they tend to be regarded as more specialised items of equipment which are kept and used by professional rescue services, such as the fire service, rather than being readily available and suitable for use by laymen.

It is therefore an object of the present invention to provide improved escape apparatus of a simple light¬ weight construction, which can be made relatively inexpen¬ sively and can be easily stored and reliably used.

According to the present invention there is provid¬ ed apparatus for controlling a descent of a person or an object, the apparatus comprising an elongate tube of flexi¬ ble material, through which the person or object is intend- ed to pass, surrounded by elastic means capable of expanding radially with respect to the longitudinal axis of the apparatus and having a smaller diameter in its unex- panded state than the diameter of the tube of flexible material so as to constrict the cross-sectional area of the interior of the flexible tube, characterized in that the elastic means comprises an elongate elastic tube extending along the length of the flexible tube.

The elastic and flexible tubes are advantageously arranged so as to allow sliding movement of the elastic tube relative to the flexible tube during the passage of a person or object therethrough.

Preferably, the elastic tube comprises an openwork structure of elastic material, which extends along the length of the tube, the openwork s^'tructure providing the required radial expandability and circumferential elastici¬ ty of the elastic tube.

In one preferred embodiment, the elastic tube comprises a tube of elastic sheet material, for example synthetic or natural rubber, having a plurality of holes formed therein. The holes may extend in generally parallel spiral lines about the longitudinal axis of the elastic tube. Alternatively, the holes may be arranged in parallel annular lines around the longitudinal axis. Additional holes of a different size may be formed in the elastic material between the first-mentioned holes. Moreover, the pattern of holes may be varied at one or more points along the length of the elastic tube so as to vary the elasticity thereof. For example, the pattern of holes may be varied at one end of the elastic tube, intended in use to be the entrance into the apparatus, to afford a less constrained entry, and optionally at other points, particularly at or near the other end intended to be the exit, to afford increased local resistance.

The apparatus preferably also includes a support for supporting the end of the flexible tube, which is intended to be the entrance, in an open position to enable a person or an object to enter the tube.

The end of the elastic tube adjacent the entrance end of the flexible tube is preferably supported either by connections to the support for the flexible tube or to the flexible tube itself. The tubes may also be connected together at the other end intended as the exit. Addition¬ ally, or alternatively, the tubes may be connected together along one or more seams extending longitudinally along the tubes . The seam or seams may be reinforced with load- bearing, substantially inextensible tape or webbing materi¬ al. In another example, the tubes may be connected togeth¬ er at spaced apart points along their lengths, so as to inhibit substantial relative longitudinal movement between the tubes .

The flexible tube may be made from fabric which is substantially inextensible in both the circumferential and longitudinal directions with respect to the longitudinal axis. Alternatively, the flexible tube may be made from a load-bearing material, such as a netting or stocking mate¬ rial, being more extensible in the circumferential direc¬ tion.

The apparatus preferably includes an outer protec¬ tive cover of flexible material which may extend partially or completely around the elastic tube. The protective cover may be made, for example, of a material which is resistant to fire, water, etc. The protective cover may be tubular with a diameter which is substantially the same as the diameter of the inner tube of flexible material.

The invention will now be further described by way of example with reference to the accompanying drawings, in which:-

Figure 1 shows schematically a side view of part of one embodiment of the present invention,

Figure 2 shows schematically a side view of part of the embodiment in figure 1, when the invention is in use, Figure 3 shows schematically a section through I-I in Figure 1, and

Fi'gure 4 shows schematically an enlarged view along II-II in Figure 3.

Referring now to the drawings, an apparatus for controlling a descent of a person or an object includes a flexible tube in the form of a tubular lining 1 of flexible material which is preferably fire-resistant having a seam 2 along its length. A tube 3 of elastic sheet material having a seam 4 along its length surrounds the tubular lining 1, with the seams 2 and 4 being connected together. The cross-sectional periphery of the tubular lining 1 is approximately five times the cross-sectional periphery of the unexpanded elastic tube 3 , although it may be more or less than five times. The diameter of the unstressed annular of the apparatus thereby formed when hanging freely is preferably about 170 mm, with the lining constricted into folds within the unexpanded elastic tube. The elastic tube is made from natural or synthetic rubber or latex sheet having a regular array of circular holes 5, the area of the holes being about 40% of the total perforated area of the elastic sheet material . The holes each preferably have a diameter of 15 mm.

The holes 5 are arranged in parallel lines extend¬ ing in a spiral formation around the longitudinal axis 6 of the tube, so as to form a staggered arrangement as shown in Figure 4. The holes have two .effects . The first is to provide a greater range of expansion from relaxed to fully expanded, with the material between the holes needing only elastic properties in one direction at once, in similar manner to a net, rather than two directions at once as with a continuous membrane. The second is to enable anisotropic elastic properties to optimise the entire arrangement, for example by using greater elasticity circumferentially than longitudinally with respect to the longitudinal axis 6.

An annular or square support frame 7 is supplied to support the lining 1 and to hold the entrance to the lining 1 open to allow a person or object to enter the apparatus. An outer protective sheath or cover (not shown) is provided over the elastic tube, the sheath or cover preferably being tubular and having substantially the same diameter as the inner lining 1.

The end of the elastic tube 3 adjacent the entrance end of the apparatus is supported by connection to the frame 7 by means of a plurality of support straps 8 con¬ nected at points around the circumference of the elastic tube.

In order to support the apparatus alongside a building for example, the apparatus could be attached to fixed strong anchor points or hooks by any suitable attach¬ ment means which, with the frame 7, provide a funnel-shaped entry into the lining. The point of entry is preferably covered with a canopy (not shown) in order to eliminate the psychological effect of heights. The exit end of the lining could be anchored to the ground and away from the vertical line of the place of descent in order for the apparatus to be inclined so as to aid in reducing the speed or descent, or to move the apparatus gradually away from the building.

The inner lining 1 is preferably attached to the elastic tube 3 without affecting its expansion and so as to allow free sliding movement of the elastic tube over the lining, this sliding movement being important in order to provide stress relief and energy absorption by means of the friction between the elastic tube and lining. The diameter of the lining 1 substantially corresponds to the maximum needed expansion of the elastic tube, and the lining could be made to any specification i.e. friction level, tensile strength, fire-retardation etc. and also from any required material.

When a person enters the lining, the apparatus expands under the influence of the elastic tube, and allows the person to pass downwards, and indeed to accelerate. When the descender feels that the speed of descent is sufficient, he can raise his knees relative to this body so that his thighs move from approximately vertical towards the horizontal thereby increasing the effective cross- section dimension of the descender. This increases the force between the descender and the tube thereby increasing resistance to descent. The descender's arms may be used in a similar way, and by the quite instinctive use of arms and/or legs, the speed of descent can easily be controlled. No effort is required to maintain the body in a braking posture with the knees partly raised, as the forces on the knees (via the lining) tend to raise them further towards the horizontal, thereby increasing the braking effect, so that the natural tendency is to slow down to rest.

The end of the inner lining may be gradually cush¬ ioned for a length of approximately 60 cms in order to facilitate the exit of the object or person by creating a separation between the lining and the elastic tube, thereby disengaging slowly the elastic tube and avoiding for exam¬ ple a person's feet from being entangled at the very end point where the restrictive properties of the elastic tube are terminated.

In the invention, the functions of the lining and elastic tube are separated and optimised. Thus the lining is optimised for lightness, strength, frictional proper¬ ties, fire resistance, tear resistance, and other relevant properties (for example a limited ability to see and breath through it) while the elastic tube is optimised for expand¬ ability with adequate fire resistance (rubber has an inher¬ ent degree of fire resistance). For the apparatus to work satisfactorily, and to be able to accommodate a range of sizes from small children to the largest adults, the elas¬ tic tube must combine adequate elastic constraining force with maximum expandability, while at the same time the lining presents an inner surface to the descender which is completely free of obstruction, to obviate the catching of limbs, protrusions from clothes and so on. The crucially important "feature of maximum expandability is achieved by the use of an openwork structure (such as a net, web, or perforated sheet) of elastic material, to bestow a greater range of expansion from relaxed to fully expanded; the elastic material in such an openwork structure is only required to stretch in one direction at once when the overall structure is stretched over an area (whereas a similar element of elastic material in a continuous mem¬ brane would have to stretch in two directions at once (at right angles). A further advantage of an openwork struc¬ ture is that the pattern can be chosen and varied to achieve overall elastic properties of the structure which vary in chosen directions (for example, greater extensibil¬ ity circumferentially than longitudinally) .

A further important feature of the invention con¬ sisting of the two element lining/elastic tube combination is that, as a descender passes therethrough, there is both increased constraining force between the stretched elastic tube and the lining and considerable relative movement, the elastic material sliding back and forth over the lining material with the passage of the descender. This relative slippage has two important effects. Firstly, it permits redistribution of stress (alleviating local stress concen¬ trations which occur round protruding limbs for example) . This confers an important advantage over the Prior Art where stress concentration and rupture can occur at attach¬ ment points between a lining and elastic containment (for example in GB 1269401 page 2 lines 61-65 and Fig. 5) . Secondly it dissipates energy within the apparatus (the sliding creating frictional heating between lining and elastic tube) so that the frictional heat generated as an inevitable consequence of descent is only partly generated (and felt) on the descender's body, the rest being generat¬ ed and dissipated within the apparatus. The material from which the protective cover is made is preferably cheap and light-weight and may be flame-retardent, heat-resistant or water-proof depending on the circumstances in which the apparatus is to be used.

The apparatus in accordance with the present inven¬ tion is simple .in construction, and can therefore be made cheaply and easily. It is also light-weight and can be easily made compact by folding or rolling for storage or for carrying. The apparatus has many applications, such as for escaping from high buildings, for descending from airborne helicopters, ships, oil rigs, etc. or even as a plaything at funfairs, swimming pools, etc. It is also intended to be readily available for purchase and storage in any building, such as domestic dwellings, offices or factories, as a fire precaution and it can be easily and reliably used by laymen. It can also be used for descend¬ ing sensitive or hazardous materials, or debris or other objects, for example on building sites.

Whilst a particular embodiment has been described, it will be understood that modifications can be made with¬ out departure from the scope of the invention.

For example, the holes of the elastic tube may be of various shapes (triangular, square, rectangular, hexago¬ nal, round, elliptical, etc. ), sizes (up to about 30 mm maximum dimension), and arrangements (holes in line, stag¬ gered holes, smaller holes between larger holes, and so on) . Holes larger then 30 mm across are preferably not used as they can catch toes or other protrusions of the descending person or object. The pattern can be varied over the area of the tube; for example an arrangement conferring greater circumferential elasticity can be used locally at the mouth of the tube to facilitate entry. Greater constrictions can be introduced along the length, or just before the exit, to increase the braking effect.

Instead of a perforated elastic sheet, the openwork elastic tube may be made from elastic material in the form of a net, or web, or may be a woven, knitted or knotted matrix of elastic thread or strips.

Additionally, even though the elastic tube could be designed to be a specific uniform diameter along its length, it could alternatively have different diameters at different intervals along its length to create an intermit¬ tent free-fall effect. The lower end of the tube could also be narrowed in diameter in order to create a braking effect or could be enlarged to create an exit effect.

Although specific dimensions for the described embodiment have been given, these dimensions can vary depending on the quality of the rubber used, or the intend¬ ed purpose or application of the apparatus.

The inner lining 1 and elastic tube 3 may not be connected at all to each other, except preferably at or near the end intended to be the entrance to the apparatus, or they may be connected at points around the circumference at the end forming the entrance and maybe also at the other end forming the exit, or at intermittent locations along their length. Also, the lining 1 could be made from a translucent material in order to enable a person passing therethrough to see the holes in the elastic tube and thereby judge their speed of descent.

When objects are to be passed down through the apparatus, it may be advantageous to use a mechanical shaker or vibrator to shake down the object. In this way, the speed of descent of the object can be controlled.

Claims

1. Apparatus for controlling a descent of a person or an object, the apparatus comprising an elongate tube (1) of flexible material, through which the person or object is intended to pass, surrounded by elastic means (3) capable of expanding radially with respect to the longitudinal axis (6) of the apparatus and having a smaller diameter in its unexpanded state than the diameter of the tube (1) of flexible material so as to constrict the cross-sectional area of the interior of the flexible tube (1), character¬ ized in that the elastic means ( 3) comprises an elongate elastic tube (3) extending along the length of the flexible tube (1) .

2. Apparatus as claimed in claim 1, wherein the elas¬ tic and flexible tubes (1,3) are arranged so as to allow sliding movement of the elastic tube (3) relative to the flexible tube (1) during the passage of a person or object therethrough.

3. Apparatus as claimed in claim 1 or 2, wherein the elastic tube (3) comprises an openwork structure of elastic material, which extends along the length of the tube (3), the openwork structure providing the required radial ex¬ pandability and circumferential elasticity of the elastic tube (3) .

4. Apparatus as claimed in claim 3, wherein the elas¬ tic tube (3) comprises a tube of elastic sheet material having a plurality of holes (5) formed therein.

5. Apparatus as claimed in claim 4, wherein the holes (5) extend in generally parallel spiral lines about the longitudinal axis (6) .

6. Apparatus as claimed in claim 4, wherein the holes (5) are arranged in generally parallel annular lines around the longitudinal axis (6) .

7. Apparatus as claimed in claim 5 or 6 , wherein additional holes of a different size are formed in the elastic material between the irst-mentioned holes (5).

8. Appar_.cus as claimed in any one of claims 4,5,6, or 7, wherein the pattern of holes (5) is varied at one or more points along the length of the elastic tube ( 3 ) to vary the elasticity of the tube (3).

9. Apparatus as claimed in any preceding claim, in¬ cluding a support (7) for supporting the end of the flexi¬ ble tube ( 1 ) , which is intended in use to form the en¬ trance, in an open position to enable a person or object to enter the tube (1) .

10. Apparatus as claimed in claim 9, wherein the end of the elastic tube (3) adjacent the entrance end of the flexible tube (1) is connected to the support (7) .

11. Apparatus as claimed in any preceding claim, where¬ in the tubes (1,3) are connected together at the end in¬ tended in use to form the entrance of the apparatus .

12. Apparatus as claimed in any preceding claim, where¬ in the tubes (1,3), are connected together at the end intended in use to be the exit of the apparatus .

13. Apparatus as claimed in any preceding claim, where¬ in the tubes (1,3) are connected together along one or more seams (2,4) extending longitudinally along the tubes (1,3).

14. Apparatus as claimed in claim 13, wherein the seam or seams (2,4) are reinforced with load-bearing, substan¬ tially inextensible tape or webbing material.

15. Apparatus as claimed in any preceding claim, where¬ in the tubes (1,3) are connected together at spaced apart points along their lengths, so as to inhibit substantial relative longitudinal movement between the tubes (1,3).

16. Apparatus as claimed in any preceding claim, where¬ in the flexible tube (1) is made from fabric which is substantially inextensible in both the circumferential and longitudinal directions with respect to the longitudinal axis ( 6 ) .

17. Apparatus as claimed in any one of claims 1 to 15, wherein the flexible tube (1) is made from a load-bearing material being more extensible in the circumferential direction.

18. Apparatus as claimed in any preceding claim, in¬ cluding an outer protective cover of flexible material which may extend partially or completely around the elastic tube ( 3 ) .