WO1996005886A1

WO1996005886A1 - Rescue device

Info

Publication number: WO1996005886A1
Application number: PCT/SE1994/000769
Authority: WO
Inventors: Evert Almqvist; Rolf Svensson
Original assignee: Intercedo Holding Ab
Priority date: 1993-02-24
Filing date: 1994-08-23
Publication date: 1996-02-29

Abstract

The present invention relates to an apparatus for downhauling people or other loads, comprising a brake which functions to limit the downhauling speed. According to the invention the apparatus includes a rotatable wheel (3; 103; 203), a rotatable roller (10; 110, 110'; 210, 210'), which is located radially outside the periphery of the wheel and which can be swung into abutment with the wheel periphery, and an elongated belt (2; 102; 202) having an incoming part which runs between the respective peripheral surface of the wheel and the roller and around a part of the wheel periphery, and an outgoing part which runs between the wheel and a device (11; 111, 111'; 210', 210) which is located radially outside the wheel and which when the belt is under load functions to swing the rotatable roller towards the periphery of the wheel and therewith brings that part of the belt which lies between the roller and the wheel into abutment with the periphery of said wheel.

Description

Rescue Device

The present invention relates to apparatus for downhauling people or other loads, which include brake means for limiting the downhauling speed.

The inventive apparatus is intended primarily for use in rescue work or as safety equipment, for instance to rescue people from burning buildings, to lower life boats into water, and as a safeguard against workmen falling from roofs and similar structures, but can also be applied in other contexts where a free-fall is to be avoided, for instance in connection with indoor "rock climbing competitions" in which artificial rock faces are constructed indoors and the winner of the competition is the person who can climb to the highest point on the "rock face", where the majority of the competitors fall from the rock face. One problem with apparatus of this kind resides in maintaining an essentially constant downhauling speed which is not contingent on the weight of the person using the downhauling apparatus.

EP-A2-0 087 650 for instance teaches a downhauling apparatus which includes a centrifugal brake which functions to retard the speed of a line drum through the medium of a gear arrangement. In the case of this known downhauling apparatus, the downhauling speed depends solely on the speed at which the drum rotates, therewith partially solving the aforesaid problem. However, the rotational speed of the drum will increase with the speed at which the diameter of the drum constituted by the amount of line wound on the drum decreases as line is taken from the drum when the apparatus is used. As a result, the difference in downhauling speed between initial and final speed may become unacceptably large when downhauling from high heights, unless the dimensions of the drum are kept within reasonable limits. An object of the present invention is to provide a reliable downhauling apparatus which includes only a few components and has relatively small dimensions and with which the downhauling speed is independent of the weight of the load and also independent of the number of turns that are taken from a storage reel in those cases when the apparatus includes such a storage reel.

This object is achieved in accordance with the invention with an apparatus of the aforedescribed kind which is characterized by a rotatable wheel, a rotatable roller, which is mounted radially outside the periphery of the wheel and which can be swung into abutment therewith, an elongated belt having an incoming or leading part which runs between the peripheral surfaces of the wheel and the roller and around part of the wheel periphery, and an outgoing or trailing part which runs between the wheel and a device which is mounted radially outside the wheel and which when the elongated belt is under load functions to swing the rotatabie roller against the periphery of said wheel and therewith bring the part of the belt that lies between the roller and the wheel into abutment with the wheel periphery. This enables the rotational speed of the wheel to be used as a control variable for adjusting the downhauling speed, this speed being equal to the running speed of the belt. This arrangement will also ensure that the belt is unable to slide relative to the wheel periphery and that the belt will constantly run at the same speed as the wheel periphery, which is an important feature from the aspect of control accuracy. The provision of a separate regulating wheel renders the rotational speed independent of the length of the belt carried on the reel and enables the belt to be wound onto a storage wheel of small diameter and which therewith requires only a small amount of space.

According to one preferred embodiment, the brake arrangement includes a brake which is controlled by the speed at which the wheel rotates. This brake may have the form of a centrifugal brake or an electric brake which is connected to the wheel axle through the medium of a gear arrangement. The rotatable wheel, the frame carrying the rotatable roller and the brake connected to the wheel axle are all carried by a yoke which, in turn, is carried by a housing and which is moveable relative to the housing against the action of a spring, wherein the housing includes brake devices against which devices which function to retard rotation of the wheel axle come into abutment as the yoke rotates against the action of the spring. In the case of this embodiment, the brake controlled by rotation of the wheel axle functions as an auxiliary brake which when applied causes the yoke to be subjected to a bending moment which acts to move the yoke relative to the housing and therewith bring the yoke-carried brake devices into abutment with the housing-carried brake devices.

The invention will now be described in more detail with reference to exemplifying embodiments thereof and also with reference to the accompanying drawings, in which

Figure 1 is a partially cut-away side view of a preferred embodiment of inventive downhauling apparatus;

Figure 2 is a sectional view taken on the line II-II in Figure i;

Figure 3 illustrates a second embodiment of an inventive downhauling apparatus;

Figures 4 and 5 are two vertical sectional views of a third embodiment of an inventive downhauling apparatus, said views being taken at right angles to one another;

Figure 6 illustrates a variant of the downhauling apparatus shown in Figures 4 and 5. The downhauling apparatus illustrated in Figures 1 and 2 includes a storage reel 1 on which a belt 2 is wound in mutually superimposed turns prior to using the apparatus. In Figure l, the belt 2 is shown fully unwound from the storage reel 1. The apparatus also includes a wheel 3 which is mounted for rotation on an axle 4 and carried by a yoke 5 which, in turn, is pivotal about a trunnion 6 mounted on a housing 7 in which the apparatus components are housed. When the apparatus is in the operational state shown in Figure 1, the yoke 5 is held free of load by means of a spring 14, which is indicated in dash-dotted lines in Figure 1 and one end of which is attached to the housing 7 at a point above the yoke, and the other end of which is attached to the yoke itself. An annular frame 8 whose inner diameter is greater than the outer diameter of the wheel 3 is mounted for rotation about an axle 9 attached to the yoke 5. Two rollers 10 and 11 are rotatably mounted on the bottom half of the frame 8, of which rollers at least the roller 10 has a diameter such, or is positioned such that part of its periphery will extend radially inwards of the inner periphery of the frame 8.

An incoming or leading part of the belt 12 runs from the storage reel 1, over a guide roller 12 and between the roller 10 and the wheel 3, and extends around the part of the wheel periphery with an outgoing or trailing part of the belt located between the roller 11 and the wheel 3, before leaving the housing through a slot 13 provided therein. Although not shown, a harness or like load support device is attached to the free end of the belt 2, so as to secure the person using the downhauling apparatus.

Two centrifugal brakes 15, 16 are mounted on and are driven synchronously by an axle 4 passing through the yoke 5, said axle being connected with a toothed ring 19 on the wheel 3 by means of a gear wheel 18. The gear wheel 18 is rotatably mounted on the axle 9 carrying the yoke, and the wheel 3 has a hub 17 which is rotatably carried by the centrifugal-brake axle 4.

In addition to the two centrifugal brakes, the illustrated exemplifying embodiment of the downhauling apparatus also includes two brake linings 20, 21 each of which is intended to coact with the outer covering 22, 23 of its respective centrifugal brake in a manner described below. The brake linings have an arcuate shape which corresponds to the outer contours of the coverings and are mounted on a holder which is pivotally carried in the housing 7 opposite respective covers 22, 23 and located slightly below the cover when the belt 2 is not under load.

The downhauling apparatus illustrated in Figures 1 and 2 works as follows.

The downhauling apparatus is hung from an intended location, for instance close to a window, by means of an eye 24 provided on the housing 7 and is then ready for use. The user then pulls an adequate length of belt from the apparatus so as to be able to secure himself/herself in the harness attached to the free end of the belt. Withdrawal of the belt from the apparatus is easy, since neither the centrifugal brakes nor the brake linings are yet active. As the belt is withdrawn, the roller 11 is acted upon by a force component which strives to move the roller to the right in Figure 1, therewith causing the frame 8 to be swung to the right in Figure 1. This also causes the roller 10 to be moved to the right and therewith press that part of the belt 2 which lies between this roller an the wheel 3 into abutment with the periphery of said wheel.

The user then goes to the window and jumps out, first having made sure that the window is open of course. The belt 2 will then unwind rapidly from the storage reel l and the rotational speed of the wheel 3 and the centrifugal-brake axle 4 will increase. The transmission effected by the gear wheel 18 between the wheel hub 17 and the centrifugal-brake axle 4 is adapted so that the centrifugal brake will become active when the rotational speed of the wheel hub 17 corresponds to a desired downhauling speed, which because the downhauling speed is equal to the peripheral speed of the wheel 3 can be easily determined.

Application of the centrifugal brakes slows down the belt while, at the same time, subjecting the yoke 5 to a bending moment which draws the yoke down until the covers 22, 23 are in abutment with the brake covers 20, 21. As the speed at which the centrifugal-brake axle rotates decreases, the centrifugal brakes are deactivated and only the brake linings 20, 21 remain active. The brake linings are dimensioned so that their braking effect is insufficient to prevent an increase in the speed at which the wheel 3 rotates and consequently, when the centrifugal brakes are deactivated the rotational speed of the wheel will again increase until the centrifugal brakes are again activated, whereafter the rotational speed of the wheel 3 will again slow down until the centrifugal brakes are again deactivated. This sequence of events is repeated until the belt is no longer subjected to load, whereafter the yoke 5 is moved to the position shown in Figure 1 by the spring 14 and the frame 8 swings to its position of equilibrium. It will be noted that each time the centrifugal brake is activated, the yoke will be acted upon by a bending force towards the brake linings and is pressed harder thereagainst, therewith also increasing the braking effect of the brake linings when the centrifugal brakes are activated.

According to one variant of the aforedescribed embodiment, the brake arrangement may comprise only one centrifugal brake. This brake will, in principle, operate in the same way as that described above, with alternating activation and deactivation of the brakes as the rotational speed increases or decreases in relation to a mean value which corresponds to the down- hauling speed. As will understood, this variant which lacks the aforesaid brake linings does not require the provision of the yoke and the wheel and the brakes are therefore journaled directly in the housing.

In addition to the obvious advantages afforded by the use of small centrifugal brakes in the variant of the invention illustrated in Figures 1 and 2, a smoother running of the belt can be achieved by correct dimensioning of brake linings and centrifugal brakes, because the belt is slowed down or braked when subjected to load even when the centrifugal brake is deactivated. In the case of the variant in which no brake linings are fitted, the belt is not slowed down when the centrifugal brake has been deactivated, meaning that the wheel will have greater acceleration than in the case of the illus¬ trated embodiment. On the other hand, this also means that the time lapses between activation and deactivation of the cen¬ trifugal brake will be shorter, meaning that the variations in downhauling speed will not be experienced as troublesome by the person using the apparatus.

Because the belt 2 by the roller 10 is held pressed against the periphery of the wheel 3 when the belt is under load, the belt will be unable to slide in relation to the wheel but moves at the same speed as the peripheral speed of the wheel, therewith insuring that the downhauling speed is always directly proportional to the speed at which the wheel rotates. A desired downhauling speed can thus be achieved by selection of the centrifugal brake and by suitable transmission between wheel and centrifugal-brake axle. Since a greater load on the belt will merely result in greater acceleration of the wheel when the centrifugal brake is deactivated and the time lapses between the brake deactivation and brake activation intervals will become shorter with no change in the mean value of the downhauling speed, the downhauling speed will be independent of the weight of the load, provided, of course, that the braking effect generated by the centrifugal brake is sufficient to retard or brake the load.

By using a separate wheel around which a single belt loop runs for regulating the downhauling speed, the downhauling speed will also be independent of the height from which downhauling takes place, which would not be the case when using the rotational speed of a roller having several superimposed turns as a regulating or control variable. If such a roller is provided with control or regulating means which keeps the rotational speed constant, the peripheral speed would decrease and therewith the downhauling speed in keeping with the rate at which the belt is taken from the roller. In the case of high heights, and therewith a corresponding number of line turns on the reel, the use of such a control variable would result in an unacceptably low downhauling speed at the end of a downhauling sequence.

According to one advantageous variant of the aforedescribed embodiment, the storage-reel axle is connected to a return spring 25, shown schematically, which may be of the kind used in a vacuum cleaner. With this embodiment, the belt is reeled automatically onto the storage reel when no load acts on the belt after use, whereafter the downhauling apparatus can be used again. This embodiment is particularly suitable when the apparatus is used as a safety device when working on rooves, in which case the apparatus may conveniently also include brushes or like devices to prevent snow or dirt from being entrained by the belt into the apparatus when winding in a fully or partially extended belt. This embodiment will also insure that the belt is always kept stretched, which eliminates the danger of the apparatus not functioning until the load has already fallen freely through some short distance.

Naturally, other belt returning means may be used, a crank or like device for instance which is capable of reeling in an extended belt and therewith enable several people to use the downhauling apparatus on one and the same occasion.

Although the embodiments illustrated in Figures 1 and 2 include two centrifugal brakes and two brake linings, it will be understood that more or fewer than two brake elements can be used within the scope of the invention. Furthermore, the brake linings included in the apparatus may coact with appara¬ tus parts other than the centrifugal-brake covers, for in- stance with the belt-free part of the wheel 3. The centrifu¬ gal brakes are preferably of the kind used in motor saws and the belt is made of the same material as that used with safety belts and safety harnesses.

Figure 3 illustrates another embodiment of the invention which differs primarily from the downhauling apparatus shown in Figures 1 and 2 by virtue of the fact that the belt is not reeled onto a storage reel carried by the same housing as the brakes and the regulating wheel. Those components of the apparatus illustrated in Figure 3 which find correspondence with the components of the apparatus illustrated in Figures 1 and 2 have been identified by the same reference signs to which a prefix of 100 has been added. In this apparatus, the belt (not shown) enters the housing through a slot 113' and leaves the housing through another slot 113, wherein the part of the belt that hangs from the slot 113 carries a harness. The part of the belt exiting through the slot 113' has a length which corresponds to the greatest height for which the apparatus is intended. In other respects, the apparatus illustrated in Figure 3 is identical with the apparatus illustrated in Figures 1 and 2, with the exception that it includes two sets of coacting rollers 110, 111 and 110', 111' which are rotatably mounted on the frame 108. The components of the Figure 3 embodiments that are not shown in the figure, the centrifugal brakes, the brake lining and the yoke carrying the frame 108, the wheel 103, the centrifugal brakes and the gear wheel 118, are thus identical to corresponding components in the embodiment illustrated in Figures 1 and 2.

The apparatus illustrated in Figure 3 works in the same way as the apparatus shown in Figures 1 and 2, with the exception that after downhauling a first load attached to that part of the belt which exits from the slot 113, the apparatus can be reused by attaching a new load to that part of the belt which hangs from the slot 113', the harness or like load-holding device also being attached to this belt-end. When downhauling a load attached to that part of the belt which hangs from the slot 113', the second pair of rollers 110', 111' carried by the frame 108 coact to hold the belt pressed against the periphery of wheel 103, whereas the remainder of the apparatus operates in the same manner as earlier described, although the belt moves in the opposite direction in the apparatus, wherewith the rotational direction of the wheel, the gear wheel and centrifugal brakes also move in the opposite direction.

One advantage afforded by the apparatus shown in Figure 3 is that the apparatus is ready for use immediately upon com¬ pletion of a first downhauling operation. One drawback with the apparatus is that the belt can be drawn from the apparatus when the fall height is greater than the length of the belt and consequently before using the apparatus it is advisable to check that the part of the belt that is intended to run through the apparatus will actually reach the ground.

A third embodiment of the invention is illustrated in Figure 4 and 5. Those components of the apparatus illustrated in Figure 4 and 5 that have the same function as corresponding components in the apparatus illustrated in Figures 1-2 have been identified with the same reference signs to which a prefix 200 has been added. The downhauling apparatus illustrated in Figures 4 and 5 includes a housing 207 and a yoke 205 which is carried by the housing, pivotal about an axle 217. The axle 217 also carries for rotation the wheel 203 around which the belt 202 runs. The wheel 203 is coupled to a centrifugal brake 215 journaled on the yoke, through the medium of gear wheels 219, 26, 27, 28 journaled on the yoke. The centrifugal-brake axle 204 carries a wheel 29 and peripherally outside said wheel two diametrically opposite brake linings 220, 220' are mounted in the housing 207. A frame 208 which carries two rotatable rollers 210, 210' is attached to the yoke 205, which is pivotally mounted on an axle 209 located in the lowermost part of the yoke. The rollers 210, 210' are mounted in the frame on both sides of a plane which passes through the axles 209 and 217. The frame works in the same way as the earlier described frames 8 and 108, such that when the part of the band hanging from the housing 207 on the right in Figure 5 is subjected to load a force component will load the roller 210' causing the frame 208 to swing clockwise in the figure and causing the roller 210 to press the intermediate part of the belt against the periphery of the wheel 203. If the part of the belt shown on the left of the figure is loaded instead, the roller 210' will press the belt against the periphery of the wheel.

The yoke 205 is also connected to the housing 207 by means of a spring 214, which when no load acts on the downhauling apparatus holds the yoke in the position shown in Figure 5.

In principle, the apparatus illustrated in Figure 4 and 5 works in the same way as the apparatus illustrated in Figure 3. When the centrifugal brake is activated as the apparatus is used, there is generated a bending moment which causes the yoke 205 to swing relative to the housing around the axle 217 against the action of the spring 214, so that the periphery of the wheel 29 will come into abutment with one of the brake linings 220, 220'. If the falling load is supported by the part of the belt shown to the right in Figure 5, the periphery of the wheel 29 will lie against the brake lining 220, and will lie against the brake lining 220' when the falling load is supported by the belt-part shown on the left of Figure 5.

Figure 6 illustrates another variant of the downhauling apparatus shown in Figures 4 and 5. This variant differs from the embodiment shown in Figures 4 and 5 solely by the fact that the brake linings 30, 30' act on the periphery of a brake wheel 31 mounted on the axle of the regulating wheel. The brake linings are mounted on two mirror-symmetrical circle- arcuate holders 32, 32', which are pivotally attached to one another at one end thereof and to the housing, and are con¬ nected to the housing at their other ends through a respective link 33 and 33' .

In the afore described variants of downhauling apparatus according to the invention, centrifugal brakes have been used as brakes that are dependent on rotational speed. It will be understood, however, that other types of rotational-speed- dependent brakes can be used, such as electric brakes. Other modifications are also conceivable. For instance, the yoke and frames can be given other configurations. The invention is therefore restricted solely by the content of the following claims.

Claims

1. Apparatus for downhauling people or other types of load, comprising a brake for restricting the downhauling speed, characterized in that the apparatus includes a rotatable wheel (3;103;203), a rotatable roller (10;110,110' ;210, 210'), which is located radially outside the periphery of said wheel and which can be pivoted into abutment with said periphery, and an elongated belt (2; 102; 202) having an incoming part which runs between the respective peripheral surface of the wheel and the roller and around a part of the wheel periphery, and an outgoing part which runs between the wheel and a device (11; 111, 111'; 210', 210) which is located radially outside the wheel and which when the belt is under load functions to swing the rotatable roller towards the periphery of the wheel and therewith bring that part of the belt which lies between the roller and the wheel into abutment with the periphery of said wheel.

2. Apparatus according to claim l, characterized in that the rotatable roller (10;110, 110'; 210, 210') and the device (11; 111, 111'; 210, 210') which swings the roller towards the wheel (3; 103; 203) are mounted on a frame (8; 108; 208) which is pivotal about an axle (9; 109; 209) extending parallel with the wheel axle.

3. Apparatus according to claim 1 or claim 2, characterized in that the brake arrangement includes a brake (15, 16; 215) which is controlled by the speed at which the wheel rotates.

4. Apparatus according to claim 3, characterized in that the brake arrangement includes a centrifugal brake (15, 16; 215) which is connected to the wheel axle through the medium of gearing (18, 19; 219, 26-28).

5. Apparatus according to claim 3, characterized in that the brake arrangement includes an electric brake which is coupled to the wheel axle through the medium of gearing (18, 19; 219, 26-28) .

6. Apparatus according to claim 4 or claim 5, characterized in that the rotatable wheel (3; 103; 203), the frame (8; 108;

208) carrying the rotatable roller (10; 110, 110'; 210, 210') and the brake (15, 16; 215) connected to the wheel axle (17; 117; 217) are all carried by a yoke (5; 105; 205) which, in turn, is carried by a housing (7; 107; 207) and which is moveable relative to said housing against the action of a spring (14; 114; 214); and in that the housing includes brake devices (20, 21; 220, 220'; 30, 30') against which devices (22, 23; 29; 31) for retarding rotation of the wheel axle come into abutment as the yoke moves against the action of said spring.

7. Apparatus according to any one of the preceding claims, characterized in that the housing (7) carries a storage reel (1) to which one end of the belt (2) is fastened.

8. Apparatus according to claim 7, characterized by means (25) for winding an extended belt onto the storage reel (1).