WO2004098716A1

WO2004098716A1 - Lowering device

Info

Publication number: WO2004098716A1
Application number: PCT/SE2004/000709
Authority: WO
Inventors: Per Johansson; Nils Karlsson; Gustaf BRONEGÅRD
Original assignee: Initium Aktiebolag
Priority date: 2003-05-12
Filing date: 2004-05-11
Publication date: 2004-11-18
Also published as: SE525895C2; SE0301379L; SE0301379D0; ATE402741T1; DE602004015446D1; EP1622687A1; EP1622687B1

Abstract

The invention relates to a lowering device (1), comprising a base part (2), an elongated handle (3), a lifeline (4) and an attachment (7) for a life harness or a safety belt, in which the base part (2) and the handle (3) are fixedly connected to each other and the base part (2) comprises guiding means (5, 6a, 6b, 6c, 6d) about which the lifeline (3) is arranged to run, said guiding means (5, 6a, 6b, 6c, 6d) comprising a brake means (5) arranged to interact with at least one other guiding means (6d) so that a second part (4b) of the lifeline (4) is arranged to bear against a fist part (4a) of the lifeline (4), which first part (4a) is arranged to bear against a first part (4a) of the lifeline (4), which first part (4a) is arranged to bear against said brake means (5).

Description

LOWERING DEVICE

TECHNICAL FIELD

The present invention relates to a lowering device for lowering of an individual, comprising a base part, an elongated handle, a lifeline and an attachment for a life harness or a safety belt, in which the base part and the handle are fixedly attached to each other and the base part comprises guiding means about which the lifeline is arranged to run.

PRIOR ART

It has been desired for long to be able to provide simple and relatively cheap safety lowering devices, so called lowering brakes, to be used by persons in distress at an evacuation situation such as in connection with domestic fires, fires in public buildings or other properties or in connection with the rescuing of persons in lifts, ski lifts or overhead cranes that have come to an arrest.

Devices to secure persons at high altitudes, such as at a building site or at mountaineering, have been known for a long time. Often, these devices comprise some type of safety harness or safety belt connected to a lifeline which in turn is anchored at a suitable place to prevent the person from falling to the ground if he/she should trip or loose foothold.

An important function of these devices is that they automatically lock the lifeline against sliding. Accordingly, the secured person should not have to exert an influence on the device for it to arrest the fall. At the same time, it is desired that the device should be easy to handle in order to minimize the risk that an incorrect handling will prevent its intended operation.

DE 198 15 193 shows a device that is intended to automatically arrest a fall of a person that is coupled to the device. The device comprises a plate (1) with a through hole that constitutes a guiding means for a lifeline (7). The plate (1) is fixedly connected to a handle (3) to which an individual can couple himself/herself via the loop (8) at the outer end of the handle. An auxiliary line (5) is also coupled to the handle (3), which auxiliary^' line is connected to the lifeline by a knot (6). The device functions such that if the individual should loose foothold, as he or she climbs down, the knot (6) will lock the auxiliary line (5) about the lifeline (7) whereby the fall is arrested. Accordingly, such a device is not useful for lowering, but has only the object of preventing a person climbing down from falling to the ground, should he or she loose foothold during the climbing down.

A couple of examples of self-locking devices intended for lowering are provided by the company North Star in Sweden. One of the products is called INDY New Speleo and the other is called Petzl stop. These devices comprise line pulleys arranged between a double-wall casing, and a spring loaded clamping handle. The devices also comprise two self-locking brake blocks and they operate by the lifeline pulling these brake blocks along with it if one does not prevent them from locking the line by keeping them "away", which is done by clamping the handle.

The fact that such self-locking lowering brakes comprise several co-operating moving parts results, in combination with the fact that the lifeline should be threaded in a particular way about the pulleys and the brake blocks, in a certain risk of misuse of the device, leading to a diminished safety. Furthermore, the devices can be experienced as being hard to control in respect of lowering speed, since the handle offers a relatively small manoeuvring interval. In a panic situation, the distressed person may experience this as something negative. Also, the relatively open design leads to an obvious risk that other objects, such as clothes or hair, entangle in the device, resulting in a risk of non- intended operation. Naturally, the entangling risk also means that the distressed person may suffer injuries, which is a disadvantage.

Another type of self-locking device is shown in US 6,267,702. The device comprises a block or a tackle (1) about which a rope (3) runs. This device is primarily intended to be used for goods connected to a first load-bearing end (8) of the rope (3). By a lever-like handle (9) comprising a brake wedge (14), automatic locking can be achieved if the counter-force at the other holder-on rope end (7) should be lost. A problem of this device is that it does not have a brake function to control the lowering speed. It is realised that the device is unsuitable for use by persons for lowering themselves down, since it would be very hard for the person to release the rope as the brake has engaged.

The type of lowering device that is most similar to the invention of the present invention is shown in SE 7214740-8. The device comprises a beam means 4 consisting of two parallel sides 4a, 4b. The sides are joined to each other by a first beam 2 and a second beam 3. The device also comprises a lever means 7, a first rope 5 intended to be attached to an individual, and a second rope 6. The second rope 6 runs about the first and second beam 2, 3 and when the device is subjected to load, for example by the weight of an individual hanging in the rope 5, the second rope 6 is self-locked and the lowering is arrested. Similar devices are also shown in US 33400964, JP 54042898 and JP 50076894. However, all of the above mentioned devices have a considerable handling disadvantage. In the event that an individual experiences the lowering as discomforting or even panics, there is a serious risk that the individual instinctively takes a harder grip of the handle, which results in an increased lowering speed, close to free fall for some of the devices.

BRIEF ACCOUNT OF THE INVENTION It is an object of the present invention to provide a self-locking lowering device for lowering of individuals, which device enables a simplified handling over other known devices.

It is furthermore an object to provide a device that only requires a small force to control the lowering speed and at the same time offers a relatively large manoeuvring interval in order to increase the individual's control of the lowering.

Yet another object is to provide a device that brakes the lowering if an individual during the lowering, by panic and to clutch himself/herself, moves the handle beyond the manoeuvring interval's position for the greatest lowering speed.

It is yet another object to provide a device that can be used also to lower an individual, such as a small child, a handicapped person or a house pet, that is unable to handle the device by himself/herself/itself.

It is also an object to provide a device that is cheaper than devices known today, without negative impact on its function or performance.

At least one of the above mentioned objects is achieved by a lowering device, comprising a base part, a handle, a lifeline and an attachment for a life harness or a safety belt, in which the base part and the handle are fixedly connected to each other and the base part comprises a first guiding means, which is also a brake means, and a second guiding means, which guiding means are arranged to interact with each other, the lifeline being arranged to run about said first and second guiding means so that a second part of the lifeline is arranged to bear against a first part of the lifeline, which first part is arranged to bear against a contact surface of said brake means, the brake means being positioned in connection with an outlet opening for the lifeline, in which outlet opening a moment point is formed, the handle and the attachment being arranged to rotate the base part in a mutual plane and about this moment point, the second part of the lifeline having an extension between the outlet opening adjacent the brake means and the guiding means, the brake means being arranged to interact with said guiding means in order to control the direction of the extension in relation to a line of gravity that runs through said moment point, whereby a first frictional force is achieved by formation of an angle between the line of gravity and the extension of the lifeline.

BRIEF DESCRIPTION OF THE DRAWINGS In the following, the invention will be described in greater detail with reference to the attached drawing figures, of which: Fig. 1 shows a longitudinal cross-section of a preferred embodiment of the lowering device, Fig. 2a, b, c show an alternative embodiment in the three positions that each relate to different operational positions,

Fig. 2d, e show a variant intended to be used when lowering small children e.g., Fig. 3 shows a view of a preferred embodiment of the lowering device,

Fig. 4 is a model for calculations, and

Fig. 5 shows an alternative embodiment.

DETAILED DESCRIPTION OF THE INVENTION

Fig. 1 shows a longitudinal cross-section of a preferred embodiment of the lowering device 1. The lowering device 1 comprises a base part 2, here in the form of a plate, at which an elongated handle 3 is fixedly connected. The base part 2 and the handle 3 are arranged in a mutual plane P and the base part 2 is arranged such that its two flat sides form outer and an inner sides, respectively. A tread 8 for a lifeline 4 (not shown) and an attachment 7 for a life harness or a safety belt are arranged in the inner side of the base part 2. A plurality of guiding means 5, 6a, 6b, 6c, 6d are arranged along the tread 8, each positioned at an inside curve and comprising a contact surface A which the lifeline 4 is arranged to bear against. Suitably, the contact surface A coincides with the inner wall of the tread in the curve. The lowering device 1 also comprises a top part 11, here in the form of a cap, arranged to cover the tread 8 and to keep the lifeline 4 in place in the tread. Together, the outer side 2 of the base part and the top part 11 provide an effective casing for the lifeline 4 and a beneficial protection against entanglement of other obj ects in the device. Preferably, the base part 2, the handle 3 and the tread 8, with its associated guiding means 5, 6a, 6b, 6c, 6d, constitute an integrated unit that beneficially can be manufactured by casting, injection-moulding, compression moulding or similar. Suitably, the material is a mouldable light metal or plastics. Thereby, the manufacturing cost for the device can be kept down. Depending on design, also the top part 11 can be manufactured in this way. Furthermore, the guiding means can be manufactured in a separate unit that is placed between the base part and the top part at assemblage. Yet another possibility is that the guiding means are constituted by pins that can have for example square or hexagonal ends for form fit in the base and top parts. In a preferred embodiment, the base part is designed as a continuous plate in which the lifeline essentially is encased, but the skilled person will realise that the base part 2 and the top part 11 not necessarily need to be continuous plates. Instead, these parts can be designed as latticed plates like a frame, in order to save material and lessen the weight of the device. It is also possible to bend a bar to make a latticed plate on which the guiding means are arranged.

The figure shows an example of a design of the tread 8 that has proved to work very well. Here, the lifeline 4 runs in through an inlet opening 9 in the section of the tread 8 that in the Fig. is situated closest to the handle 3 and arranged perpendicularly to this. In connection with the upper end of the base part 2, the lifeline 4 is deflected to the left and is led to and about guiding means 5 like a hair pin curve. Then, the lifeline follows the tread 8 about the three guiding means 6a, 6b and 6c, past the guiding means 6d, in order finally to be led out from the lowering device via outlet opening 10.

In the portion of the outlet opening 10, a gap is formed in which the lifeline 4 meets itself. The gap width in this portion is adapted to the diameter of the lifeline and is somewhat smaller than the total width of two line diameters. Thereby, a first part 4a of the lifeline that is arranged to bear against the guiding means 5, is also brought in contact with a second part 4b of the lifeline heading out via outlet opening 10.

In a first embodiment, the lowering device 1 comprises a tread 8 designed as shown in Fig. 1. As to the outer shape of the base part 2, the handle 3, the attachment 7 and the cap 11, other designs can naturally be conceived without altering the function of the device. It is realised that the device can be designed with rounded corners. The base part 2 and the cap 11 can .e.g. be of circular shape and the handle 3 can be designed to be more grip-tailored. Thanks to the design of the device, in which a considerable part of the braking frictional force is formed between the different parts of the lifeline, and the fact that the lifeline runs through the device, cooling/conveyance of the frictional heat from the guiding means of the device is achieved. This diminishes the risk of overheating, especially in case of long lowering distances or repeated use in a short time interval, which otherwise could lead to impaired strength and handling difficulties. From a manufacturing point of view, this will also result in a greater flexibility in choice of material.

Figs. 2a, 2b and 2c all show an alternative embodiment of the device. Here, the device has been given an outer shape aiming at giving additional manufacturing advantages. Sharp corners and edges have been reduced, which can be experienced as more comfortable at use. The device is shown in three different operational positions, where:

Fig. 2a shows a position in which the device has locked the lifeline against gliding,

Fig. 2b shows a lowering position, and

Fig. 2c shows a "panic position" in which the device locks the lifeline.

Moreover, Fig. 2d shows a variant of the device in which the "panic position" does not give a locking of the lifeline.

With Fig. 2a as a starting point, the design of the device will be described in greater detail. The function of the design in the three positions is described further below.

Fig. 2a shows a cross-section of the lowering device 1. The device 1 comprises an essentially circular base part 2, the flat sides of which forming an outer and an inner side. On the inner side, guiding means 5, 6a, 6b, 6c, 6d, 12, 13 are arranged that together with two borders 15a, 15b form a tread 8 for the lifeline 4. An attachment 7 for a safety harness is arranged in a flange on the outer edge of the base part 2. The guiding means 5, 6a, 6b, 6c, 12, 13 comprise circular cylindrical rods or rolls that can be fixedly attached to the base part 2 by e.g. screwing, riveting or gluing. The guiding means are preferably integrated with the base part. The device also comprises a top part in the form of a cap (not shown) that, as has been described above, is arranged to cover the tread 8 and keep the lifeline 4 in place about the guiding means.

The lifeline 4 is arranged to run in the device 1 via an inlet opening 9 in the lower edge of the base part and situated behind the attachment 7, as seen in a direction from the handle 3. Thereafter, the lifeline 4 is arranged to be led up about guiding means 13, positioned adjacent guiding means 5 where it is deflected about 180°, where after it is led back down towards the lower edge of the base part 2 where it is led into the gap formed between the two borders 15a, 15b. The borders 15a, 15b run along the circular outer edge of the base part, along the half of the base part that faces the handle 3. The gap between the two borders mouths in connection with guiding means 5 where the lifeline is arranged about the guiding means 5, 6a, 6b, 6c, 6d in the same way as is described in connection with Fig. 1. Thereafter, the lifeline 4 exits via an outlet opening 10 positioned in connection with the gap that is formed between the two guiding means 12 and 5 at the upper edge of the base part.

Hereby, the lifeline 4 will three times pass the gap between the two opposing guiding means 5, 12. The width of the gap is adapted to the diameter of the lifeline and corresponds essentially to the total width of three line diameters, which means that the part of the lifeline that is about to exit the outlet opening 10 will be surrounded on either side by other parts of the lifeline and will be brought into light contact with these.

The device can also be designed such that the inlet opening 9 is placed in front of the attachment 7 and then guiding means 13 will be omitted and borders 15a, 15 will be shortened, which is shown in Fig. 2d. This embodiment will have the same function as the preferred embodiment shown in Fig. 1.

From guiding means 6d and up to outlet opening 10, the second part 4b of the lifeline 4 will be given an extension R that relates to a line of gravity L by a deflection angle v, the size of which can be controlled by the handle 3. By controlling the angle v, a person that is coupled to the attachment 7 can control the lowering speed, which is now to be described.

DESCRIPTION OF THE FUNCTION The effect of the tread 8 on the function of the device will now be described with reference to Figs. 2a, 2b, 2c and 2d, that represent three different functional positions, supported by the calculation model of Fig. 4.

When used by an individual to lower himself/herself, the lowering device should be oriented such that the handle 3 will have an essentially horizontal extension and then the base part 2 will essentially be oriented in a vertical plane. Furthermore, the inlet opening 9 for the lifeline should be downwards oriented and the outlet opening 10 should be upwards oriented. The lowering device is anchored in a suitable way and at a suitable object, by aid of the upper part of the lifeline that exits the outlet opening 10. The lower, incoming part is freely suspended. The individual is coupled to the attachment 7 by a safety harness. By pulling any of the parts of the lifeline 4 that project from the lowering device, the position of the lowering device along the lifeline is controlled such that the upper, anchored end is kept as short as possible and preferably stretched, without obstructing the individual when he/she is to climb out from a window, a balcony, a roof e.g., to lower himself/herself down.

Fig. 2a shows a position in which the lowering device 1 has locked the lifeline 4 so that lowering is prevented. When the individual hangs in the harness, the lowering device 1 will lock the lifeline and prevent gliding as soon as the upper part of the lifeline 4 is stretched. Suitably, the safety harness is designed such that the individual hangs with his/her face facing the lowering device that suitably should be in level with the head of the individual.

The individual may then loosen the brake by grabbing the handle 3 and bringing it downwards, whereby the deflection angle v between the line of gravity L and the extension R of the lifeline decreases. Then, the lowering device will slowly begin to glide downwards. Then, the individual may control the lowering speed by either increasing or decreasing the deflection angle v by varying the deflection of the handle 3 correspondingly. The deflection takes place in the plane P of the base part, as a rotating movement. Suitably, the device is designed such that the control of lowering speed takes place by a variation of the deflection angle v in a control interval of 30-45°. Hereby, a control interval will be achieved that allows less accurate movements at the same time as the need of a big variation of the handle 3 deflection is avoided to increase or decrease the lowering speed, which contributes to the feeling of security of the individual.

In the position in which the second part 4b of the lifeline runs vertically up from guiding means 6d and further out via outlet opening 10, i.e. when the extension R of the second part 4b of the lifeline and the line of gravity L coincide with the vertical line, the device has its least braking effect, shown in Fig. 2b.

A steady lowering can be achieved thanks to guiding means 6a, 6b, 6c, 6d. In case the individual, by panic, should grasp the handle and press it downwards, the lowering device is designed to somewhat brake the speed or alternatively to arrest the lowering, which corresponds to the "panic position" shown in Fig. 2c. Here, the individual has brought the handle 3 further down, past the position in which the increase of speed is the largest, whereby the lifeline 4 is guided anew in the portion adjacent outlet opening 10. In this position, guiding of the load-bearing, exiting part 4b of the lifeline 4 will take place about guiding means 12, whereby a clamping force is generated against the entering part 4c of the lifeline 4 that bears against guiding means 12. According to the same mechanism as in the arresting position in Fig. 2a, a frictional force F2_f is achieved between the two line parts that are pressed against each other accordingly, whereby the lifeline is locked and the lowering is arrested.

From one aspect, it may be desirable that such a panic reaction does not result in a complete arrest of the lowering, and in that case the lowering device can be designed with a tread 8 for the lifeline 4 according to Figs. 1, 2d and 3. By such a design, the "panic position" has no arresting effect but only a braking effect as compared to the "full speed" position in Fig. 2b. The braking effect is caused by the frictional forces that are achieved about the guiding means 12. In an embodiment according to Fig. 1, the same function is achieved in the panic position. Thanks to this design of the tread 8, a panicking individual can stay hanging in the rope by clutching himself/herself tight to the handle. If the individual on the contrary and in panic lets go of the handle 3, the own weight of the individual will, by the positioning of the attachment 7, result in a braking moment about a moment point M in the outlet opening 10, whereby the device immediately will return to the arrest position according to Fig. 2a. In this position, the attachment 7 is positioned vertically below the outlet opening 10, so that the line of gravity L through the upper load-bearing end of the lifeline coincides with the attachment 7.

It has also been shown that the device can be used to lower an individual that is unable by himself/herself to handle the device, such as a child, a handicapped person or a pet, which is shown in Figs. 2e and 2f. At use in this way, the individual that is to be lowered down is suitably provided with a safety harness that is coupled to the exiting end 4b of the lifeline. The lowering device is suitably anchored by aid of a rope or some other means of attachment, in the attachment 7. Then, the lowering is controlled by another individual who handles the device in the same way as in personal lowering, i.e. by deflecting the handle 3 in the rotating movement in the plane P, in order thereby to control the frictional force against the brake means 5, as has been described above. When used in this way, the base part need not be oriented in a vertical plane, since moment effect is achieved by interaction of the traction force in the lifeline and the anchoring of the device in the attachment. The device also has the advantage that if very light individuals are to be lowered, the tread can be shortened in order to decrease friction. This is most easily done by not guiding the entering, first part 4a of the lifeline into the inlet opening 9, but instead into the outlet opening 10 adjacent the brake means 5 and in parallel with the second, exiting part 4b, such as is shown in Figs. 3e, 3f.

Fig. 3 shows yet another alternative embodiment of the lowering device. Here, the tread 8 has been given a design that enables a more gentle control of the lowering speed. A lowering device according to this embodiment may also be used to lower an individual who cannot handle the device by himself/herself, according to the same principle as is described in connection with Fig. 2d. By a tread according to this preferred embodiment, very light individuals can be lowered without modifying the guiding of the lifeline in the tread. As is apparent from the Fig., the major difference in relation to previous embodiments is that the attachment 7 is placed farther up along the outer edge of the base part 2, which results in that a larger deflection angle v is achieved, and that a number of guiding means 6a, 6b, 6c, 6d are positioned to give a tightening force of the loose, entering end of the lifeline before the brake means 5 instead of after the same. The Fig. also shows a hole 15 intended for a screw union of the base part and the top part.

Fig. 4 shows a calculation model for the lowering device. The operation of the device is based on that the weight of the individual himself/herself gives rise to a moment M in connection with guiding means 5, in the following called the brake means, whereby a frictional force F_f results between a first part 4a of the lifeline and the brake means 5, and between the first part 4a and the second part 4b where these meet each other in the gap adjacent the outlet opening 10. By controlling the size of this frictional force F_f, the lowering speed can be controlled and even arrested. By an ingenious design of the tread 8, no counter force is required in the freely suspended part of the lifeline in order to achieve this frictional force F_f. Thereby, a sole individual may rescue himself/herself without assistance of somebody else already being down. It is also achieved a device that has proven to be very simple to handle and that does not require any considerable force for use thereof.

By the design of the tread 8, in which also the exiting and load-bearing second part 4b of the lifeline 4 is guided about the brake means 5, a clamping force is achieved that corresponds to the normal force N, from the second part 4b of the lifeline and on the intermediate first part 4a of the lifeline 4, which first part is thereby brought to bear against the brake means 5. The size of the clamping force, i.e. the normal force N, is given by the relation:

N = sin v mg ; where v is the guiding angle formed between the line of gravity L that runs through the moment point M and the extension of the lifeline R between the brake means 5 and the guiding means 6d.

The normal force in turn gives rise to a frictional force F_fr according to the relation:

F_f = N • μ_mperope ; where μ_roperope is the coefficient of friction for rope against rope.

In the position in which the lifeline is locked against gliding (Fig. 2a), the frictional force Ff and the line force S₁ together correspond to the force of gravity mg, according to the relation:

S_x = mg-F_f

It is furthermore realised that if no counter force is to be required in the free, incoming end 14 of the line, it must be true that:

S₂ = F_f

When the individual wishes to lower himself/herself down, the frictional force F_f can be decreased by decreasing the angle v by aid of the handle 3 that is brought downwards. By increasing or decreasing the deflection of the handle 3, the angle v can be varied in order to control the lowering speed. The greatest lowering speed, or rather the greatest increase of speed, is achieved in the position shown in Fig. 2b, in which the lifeline runs vertically up from the guiding means 6d and further out via outlet opening 10.

By the design of the tread 8, a basic friction is given about three of the guiding means 6a, 6b, 6c, which basic friction is adapted in this case to brake about 70 % of the body weight of the individual hanging in the lowering device. The basic friction is calculated with reference to Fig. 4, according to the following relation: In theory, equilibrium means that:

O _ C . a^a'

^{1 2} ; where α is the total change in angle of the rope and μ is the coefficient of friction between rope and aluminium/plastics.

α = 1.6 turns μ = 0.2

In order for the system to be in equilibrium, S2 must be able to counteract by:

Given the above, it is realised that the skilled person easily can do some modifying of the tread 8 (such as changing the coefficient of friction, the guiding angle or the number of guiding means), if it is desired to make certain adaptations to other conditions.

Fig. 5 shows, in detail, yet another variant of the lowering device. Here, the tread has been given an extension that will result in an extended contact surface B between the first, incoming part 4a of the lifeline and its second, exiting part 4b. This results in that a larger part of the braking friction is taken between the two line sections 4a, 4b and it has been shown that this embodiment gives a more gentle control of the lowering speed. A deflection stop 20 in the outlet opening is also shown in this variant. This deflection stop 20 is positioned such that the exiting part 4b of the lifeline is prevented from deflecting more than half the line diameter towards the first part 4a of the lifeline, as there otherwise may be a risk that the lines position themselves side by side about the guiding means 5, which would result in a decreased braking effect.

Fig. 6 shows yet another variant of the lowering device. This variant constitutes a more simple embodiment that all the same allows for braking/arresting in the so called "panic position", by the device being provided with a third guiding means 12, that is also a brake means, similar to the design in Fig. 2c. In order to allow this function, the device has been provided with at least one additional guiding means 6a, placed between the third and the first guiding means 12 and 5, respectively, as seen in the direction of the tread. It is realised that several intermediate guiding means 6b, 6c can be used, or alternatively the border 15a, to allow a line path that allows a panic position function. ALTERNATIVE EMBODIMENTS

The invention is not limited to that described above but may be varied within the scope of the claims. It is for example realised that other treads can be conceived in accordance with the scope of the invention. The skilled person will for example realise that the number of guiding means and their size, i.e. their diameter, can be varied. It is also realised that the tread can be deflected in additional directions, so that its path will run in more than one plane, either being parallel to each other or crossing each other.

The base part 2 and the top part 11 and the handle 3 and the attachment 7 may constitute an integrated unit that may give manufacturing advantages. It may also be a functional advantage that the device can not be disassembled, as there otherwise may be a risk that someone is tempted to exchange the lifeline or in other way modify the device.

The device can also be designed such that the base part 2 and the top part 11 constitute two mirrored parts that each holds a part of the guiding means, so that the longitudinal parting line is positioned symmetrically in the device.

The lowering means can be offered together with different safety harnesses adapted for the different applications. As an alternative, different variants of the lowering device are offered for different applications. Suitably, these can be provided with safety harnesses intended therefore, and suitably the safety harness is stationary connected with the lowering device in order to facilitate handling.

Claims

1. A lowering device(l), comprising a base part (2), a handle (3), a lifeline (4) and an attachment (7) for a life harness or a safety belt, in which the base part (2) and the handle (3) are fixedly connected to each other and the base part (2) comprises a first guiding means (5), which is also a brake means, and a second guiding means (6d), which guiding means (5, 6d) are arranged to interact with each other, the lifeline being arranged to run about said first and second guiding means (5, 6d) so that a second part (4b) of the lifeline (4) is arranged to bear against a first part (4a) of the lifeline (4), which first part (4a) is arranged to bear against a contact surface (A) of said brake means (5), the brake means (5) being positioned in connection with an outlet opening (10) for the lifeline (4), in which outlet opening a moment point (M) is formed, the handle (3) and the attachment (7) being arranged to rotate the base part (2) in a mutual plane (P) and about this moment point (M), the second part (4b) of the lifeline having an extension (R) between the outlet opening (10) adjacent the brake means (5) and the guiding means (6d), the brake means (5) being arranged to interact with said guiding means (6d) in order to control the direction of the extension (R) in relation to a line of gravity (L) that runs through said moment point (M), whereby a first frictional force (F_f) is achieved by formation of an angle (v) between the line of gravity (L) and the extension (R) of the lifeline, characteri s ed in that the base part (2) also comprises a third guiding means (12) which is also a second brake means positioned adjacent the outlet opening (10), and a fourth guiding means (15a, 6a), an incoming part of the lifeline being arranged to run about said third and fourth guiding means (12, 15a, 6a), and the second part (4b) of the lifeline being arranged to bear against the incoming part (4c) of the lifeline to form a second frictional force (F2_f) when the base part has been rotated such that the angle (v) between the line of gravity (L) and the extension (R) of the lifeline is formed in direction towards said third guiding means (12), as seen from the line of gravity (L) .

2. A lowering device (1) according to claim 1, characteri s ed in that the second part (4b) of the lifeline is arranged to achieve a clamping force (N) against the first part (4a) of the lifeline, whereby the brake means (5) is arranged to achieve a frictional force (F_f) between the first part (4a) of the lifeline and the second part (4b) of the lifeline and the contact surface (A) of the brake means (5).

3. A lowering device ( 1 ) according to claim 2, characteri s ed in that the handle (3) is arranged to be able to vary the angle (v), whereby the size of the frictional force (F_f, F2_f) can be varied.

4. A lowering device (1) according to claim 1, characterised in that the base part (2) and the handle (3) are fixedly connected to each other and preferably constitute an integrated unit.

5. A lowering device ( 1 ) according to claim 1, characteri s ed in that the base part (2) and the attachment (7) are fixedly connected to each other and preferably constitute an integrated unit.

6. A lowering device (1) according to any one of claims 1-5, characteris ed in that said attachment (7) is positioned such that a braking moment is achieved when the force of gravity of an individual is applied to said attachment (7).

7. A lowering device (1) according to claim 6, characterised in that the attachment (7) and the handle (3) are arranged on each side of the line that notes the extension (R) of the second part (4b) of the lifeline.

8. A lowering device ( 1 ) according to claim 7, characteri s ed in that the base part (2) comprises a deflection stop (20) positioned in connection with the outlet opening (10) and positioned such that the second part (4b) of the lifeline is given a deflection in direction towards the first part (4a) of the lifeline that is half the diameter of the lifeline at the most.