EP1351878B1 - Emergency braking device for a vehicle towed or suspended by cables and vehicle equipped with such a device - Google Patents

Abstract

The load or the working platform is suspended and displaced by at least a pair of cables whereof the stresses are equivalent. Advantageously, each pair of cables is controlled by an emergency braking device comprising means for detecting the slack strand on one of the cables of the pair and controlling a braking on the other cable of the pair. So as to avoid an impact during the emergency braking, the working platform is also equipped with a shock absorbing device.

Description

The present invention relates to an emergency braking device for any vehicle, load or object, towed or insured by at least two cables whose normal operating voltages are equivalent. The invention relates to similarly any vehicle, load or object, towed or insured by at least one cable, fitted with an emergency braking device and capable of being fitted with a shock absorbing device.

We know many translation systems on an oblique plane or according to a vertical in which a vehicle, a nacelle or a load any one is towed by at least two cables. Cable cars, like carts or funiculars traveling on an oblique plane, as well as elevators, freight elevators, facade maintenance cradles or crane hooks running vertically, are advantageously provided with traction systems comprising at least one pair of cables, each of said cables cables being subjected to an equivalent tensile force under normal conditions.

SU 1,470,653 A and EP-A-0 686 595 each describe a device for emergency braking for a load pulled by two strands of the same cable.

Application WO 01/38217 describes an elevator or a nacelle facade maintenance provided at each end with an on-board winch with two cables and differential means for balancing the tensile forces on these two cables. Other means of balancing forces on two cables can be used, for example by suspending the platform or the vehicle tow at least one cable passing through a pulley or a block attached to the vehicle or nacelle thereby creating at least one pair of suspension strands. In the following description and in the claims, we will speak of cables of a pair of cables, even if it is a pair of strands of the same cable. Depending on the configuration of the suspended object, the cables considered here may be cables used for the traction of said object or cables intended only to ensure the emergency braking of this object, the means of traction then being of another type.

In order to ensure effective safety for the vehicle or the nacelle, it is necessary to install there an emergency braking device capable of being actuated in the event of a cable break in a pair of cables.

Different emergency braking devices provided for vehicles or nacelles as described above have been proposed. We know in especially the devices detecting an overspeed and then actuating a braking device. The reaction time of these devices being high, the vehicle or nacelle has already fallen quite significantly before being braked. Other devices require a source of electrical energy to operate, simultaneous rupture of the power source and a cable could be harmful. In addition it is also a question of considering the mode of action of the braking device, that is to say the object where it applies. Most of vehicles or nacelles described include a fixed element, rail or cable carrier, arranged along the path of the vehicle, on which jaws act of the emergency braking device. The presence of such a structural element fixed, if its only function is to allow emergency braking, increases the cost of the emergency braking device.

Furthermore, in the event of a cable break, the mass formed by the nacelle, winches and the personnel and equipment installed in the nacelle is suddenly accelerated, until the emergency braking device worked. Since generally the emergency braking device works by jamming or blocking a jaw on an intact cable, the stop imposed by this device is extremely abrupt with a very strong deceleration. This stopping shock can be harmful both for the personnel in the nacelle only for the material and the equipment which undergoes it.

A first object of the invention is therefore to propose a device for emergency braking capable of braking any object, load or vehicle towed by minus a pair of cables with equivalent tensile forces, which is improved compared to known devices.

Another object of the invention is that the emergency braking device above is able to operate without an external power source.

Another object of the invention is that the emergency braking device above does not require any fixed structural element for its operation.

Yet another object of the invention is that the braking device above is of simple construction, so as to be suitable for reliable and fast operation, minimizing the fall of the object, the load or towed or insured vehicle.

Yet another object of the invention is to provide a vehicle provided at least one emergency braking device as above.

Yet another object of the invention is to provide a vehicle provided an emergency braking device as well as a damping device.

These various aims are obtained first of all by a device for emergency braking according to the invention, including a preferred embodiment is described in claim 1 as well as by a vehicle as mentioned in the claim 5. Particular or alternative embodiments are described in the dependent claims.

la figure 1 représente une portion d'une charge, ici une nacelle suspendue, équipée d'un dispositif amortisseur disposé selon une première forme d'exécution,

la figure 2 représente la même charge équipée d'un dispositif amortisseur disposé selon une deuxième forme d'exécution,

la figure 3 représente une charge équipée d'un dispositif amortisseur disposé selon une troisième forme d'exécution,

la figure 4 représente une charge équipée d'un dispositif amortisseur disposé selon une quatrième forme d'exécution,

la figure 5 représente schématiquement une première portion d'un dispositif de freinage selon une forme d'exécution préférentielle de l'invention, et

la figure 6 représente schématiquement une deuxième portion du dispositif de freinage de la figure précédente.

The description below of several alternative embodiments of damping devices, then of a preferred embodiment of an emergency braking device according to the invention, further describes some additional advantages of these devices. This description is to be considered with regard to the appended drawing comprising the figures where:

FIG. 1 represents a portion of a load, here a suspended nacelle, equipped with a damping device arranged according to a first embodiment,

FIG. 2 represents the same load equipped with a damping device arranged according to a second embodiment,

FIG. 3 represents a load equipped with a damping device arranged according to a third embodiment,

FIG. 4 represents a load equipped with a damping device arranged according to a fourth embodiment,

FIG. 5 schematically represents a first portion of a braking device according to a preferred embodiment of the invention, and

Figure 6 schematically shows a second portion of the braking device of the previous figure.

The description below shows that the subject of the invention is applied as an example to the operation of a nacelle intended for maintenance of building facades. Those skilled in the art will understand that it is possible to apply the different embodiments of the subject of the invention to other types of vehicles, loads or objects.

Figure 1 shows a nacelle 1 of which there is a face 10 of a first end. In this figure, the nacelle 1 comprises a winch 2 of which distinguishes here only the two drums 20 and 21 each responsible for winding or unroll one of the cables 30 or 31 from a set of suspension cables 3. The ends of the cables 30 and 31 opposite those wound on the drums 20 and 21 are fixed at fixed points, for example a beam suspension. Such a nacelle corresponds to that described in the WO application 01/38217 mentioned previously.

Basket 1, which should be considered here as a load any hanging, further comprises a plate or plate 4 provided with a extension acting as slide 40, slidably mounted in a slide acting as a slide 41, itself fixed to the wall 10 of the nacelle 1. The plate 4 is therefore able to move, in the direction vertical, of a determined value relative to the nacelle 1. The end of the slide 40 opposite to that fixed to the plate 4 is fixed to a crosspiece 42 each end of which supports a damper 43,44, acting between said cross end and a fixing point 430, 440 integral with the wall 10 of nacelle 1.

An emergency braking device 5, including an embodiment preferential will be described in more detail later, includes a first brake device 50, capable of locking the cable 30 as well as a second device brake 51 acting on the cable 31. Each of the brake devices 50 and 51 is actuated by a detector, respectively 52 and 53. In general, the detectors 52 and 53 can be of any known type, detecting by example a loss of tension, a slack streak or an overspeed, being of the type mechanical, electronic or electromechanical. We can have one of detector which is of a first type, for example detection of soft strand then that the other detector is of a different type, for example overspeed. In order to increase security, each detector may be able to control, in the event of an incident, the emergency braking of the two braking.

Plate 4 is shown here as consisting of a plate bearing the various components described on one side; in fact she will be from preferably covered with a case to protect these components.

The other end of the nacelle 1 is equipped in the same way.

In the event of a cable break 30 or 31, anywhere in the the length of said cable, the broken cable detector, in the case where it is a slack or loss of tension detector and / or the detector mounted on the other cable, in the case of an overspeed detector, acts to control the actuation of the emergency braking devices 50 and / or 51.

Given that, following the cable break, nacelle 1 had started its fall, actuation of the emergency braking device on the remaining cable immediately blocks the fall of the basket. For a nacelle according to art anterior, not equipped with a damping device, this stopping shock is likely to inconvenience personnel installed in the basket and / or damage the nacelle equipment.

On the other hand, for a nacelle equipped as shown here with a plate 4 carrying the braking devices 5, slidably mounted on nacelle 1, and connected to the latter by shock absorbers 43 and 44, the shock is strongly amortized, which is favorable for both staff and on-board equipment.

Figure 1 shows that the plate 4 is connected to the nacelle 1 by two shock absorbers 43 and 44 operating under compression. It is obvious that we might just as well have one, or more than two, shock absorbers work in compression as here or in traction. The shock absorber (s) can be of any known type, for example hydraulic, fluid or gas, or spring-loaded, or elastomeric compression in the case of shock absorbers operating at compression.

According to this preferred embodiment of the invention shown in Figure 1, only the emergency braking device 5 is mounted on the plate mobile 4.

Figure 2 first shows a variant of the device for driving the nacelle where the winch 2 is no longer placed on the nacelle 1, but on a fixed part of the building in front of which the basket is moved. In this case, the two cables 30 and 31 represent the two strands of the same cable passing through a return pulley 23, mounted on the nacelle 1 as described below.

The figure also shows a second embodiment of the damping device where the emergency braking device 5 as well as the return pulley 23 are mounted on the movable stage 4. A device for slides 45 allows the relative movement of the plate 4 relative to the platform or suspended load 1. As before, the plate 4 is provided with a crosspiece 46, the two ends of which are connected to the points hooking 430 and 440 of the nacelle 1 by shock absorbers 43 and 44. The operation of the device is absolutely similar to what has been described previously, the difference between the two embodiments residing in the fact that for the second embodiment of Figure 2, the mass undergoing a shock on stopping is more important than for the first embodiment, given that more elements are mounted on the plate 4.

Figure 2 also shows a hook 11 to properly represent the fact that the devices according to the invention can be applied to any load suspended:

Figure 3 shows yet another embodiment where the emergency braking device 5 as well as the damping device are carried over to one end of a support structure 6 in the form of a swan neck rigidly fixed to the nacelle 1. This type of nacelle construction is generally used for very long nacelles on which the points of suspension cables are not arranged at both ends of the nacelle but are carried towards the interior of the nacelle. In this case, the axes of the motors 22, winches 2 and drums 20 and 21, or idler pulleys, are arranged perpendicular to the longitudinal axis of the nacelle 1. In order to balance the gondola, the suspension cables 30 and 31 of each pair of cables are brought as shown here in a plane containing the axis longitudinal of the nacelle by means of a support 6 in the form of a swan neck and a set of pulleys 60. As a variant, the cables 30 and 31 of each pair could just as well be brought into a plane perpendicular to the axis longitudinal of the nacelle by support means 6 and pulleys 60 of same type. The emergency braking device 5 comprises as previously a brake device 50.51 and a detector 52.53 for each cable, arranged on a plate 4, mounted movably relative to a portion 61 of the support 6. One or more shock absorbers 62, mounted between the plate 4 carrying the braking device 5 and a fixed part 63 of the support 6, perform the same function as that described above.

Figure 3 shows a variant of the mobile fixing device of the plate 4 on the support structure 6, respectively on the nacelle 1. In this variant, the relative displacement of the plate 4 relative to the portion 61 of the support 6 is obtained by a set of links 47 forming a parallelogram deformable.

Yet another embodiment is shown in Figure 4 where the winch 2, comprising the two drums 20 and 21 driven by the motor 22 are arranged on a fixed part of the installation, for example on the roof of the building served by nacelle 1. Preferably the two drums 20 and 21 are driven by a single motor 22, being coupled together by a device differential 24, as described for example in application WO 01/38217.

In this embodiment, and contrary to what has been described previously, the braking device 5, comprising the brakes 50 and 51 thus that detectors 52 and 53, operating as described above, is also arranged on a fixed part of the installation, respectively on the same part fixed than that where the winch is mounted 2.

The figure also shows two variants in the placement of the damping device. For example, the cable 30 is connected to the face end 10 of the nacelle 1 by means of a plate 4, the point of fixing the cable to the plate being marked at 302, which plate 4 is suspended from the nacelle by a shock absorber 48 connected to a fixed point 430 of the nacelle. According to the other variant, the braking device relating to the cable 31 is mounted on a plate 4, suspended from a fixed point 450 of the fixed part of installation by one or more shock absorbers 49. In the latter case, the end of the cable 31 is directly fixed to the nacelle 1 by the fixing point 311. It is obvious that, for a given installation, the two cables 30 and 31 are connected to the nacelle in the same way, either directly, by points 301 and 302, the plate 4 then supporting the two detectors 52, 53 and the two brakes emergency 50, 51, or via the plate 4, as represented by the points of fixing 302 and 312.

The same execution variants as that described opposite one or other of the proposed embodiments are obviously interchangeable between said embodiments.

The following figures show an emergency braking device according to a preferred embodiment of the invention.

Figure 5 shows a portion of such a device in which we see a first soft strand detector mounted on one of the cables and acting on the other cable for braking. The system is highly schematized in order to better understand how it works.

On a plate 4, of which only a portion of the bottom is seen here, we distinguishes a first soft cable detector 52, capable of detecting the state of tension of the cable 30, and controlling the brake 51 acting on the cable 31. The emergency brake 51 here comprises two brake shoes 510, arranged on both sides and at least partially enclosing the cable 31. Said jaws are provided with guide ribs 511, capable of cooperating with corresponding 512 oblique grooves in a brake lever 513 as well as in a support plate 514. The brake lever 513 is pivoting about an axis 515 fixed to the plate 4, being pushed in the direction indicated by arrow B by a spring 516 bearing on a fixed portion of plate 4. The other end of the brake lever 513 is connected to the detector 52, itself constituted by a control lever 520 pivotally mounted around an axis 521 fixed to the plate 4, a first end of said lever carrying a caster 522 bearing against the cable 30, the other end of this lever being connected to the brake lever 513 by a link 523.

When the cable 30 is stretched, the roller 522 comes to bear on a generator of this cable and opposes movement in the direction of the arrow B of the brake lever 513 imposed by the spring 516, thus tending to keep the jaws 510 in position separated from each other.

In case of cable break 30, the roller 522 is no longer retained in position and the control lever 520 pivots around the axis 521 according to the direction of arrow A. By the play of the levers and links, the brake lever 513 is no longer retained and can rotate in the direction of arrows B and C under the action of the spring 516, this pivoting controlling the bringing together of the two jaws 510, by the cooperation of ribs 511 and grooves 512 of the brake lever 513 and support plate 514.

Figure 6 shows the corresponding portion of the braking, comprising the second soft strand detector 53, capable of detecting the tension state of the cable 31 and capable of controlling the brake 50 on the strand 30.

In a similar manner to what has just been described, the loss of cable tension 31 allows the lever 530 to pivot according to arrow A, which allows the brake lever 503 to pivot around the axis 505 under the action of the spring 506, thus bringing the two jaws 500 closer together guided by the ribs 501 and the grooves 502.

So therefore, in the event of a break or drop in voltage in one of the cables, the braking device acts immediately to block movement lowering the vehicle or nacelle by locking on the other cable.

So we see that the emergency braking device as it comes to be described perfectly fulfills the conditions laid down, namely, being able to operate without an external power source or any external element, and whose construction is simple thus making its operation safe and fast.

Another advantage of an emergency braking device as described is visible in Figures 5 and 6. In the event of a malfunction of the or winches actuating cables 30 and 31, the nacelle, respectively the braking device attached to it, may have to take a very tilted position. This arrangement is represented in the figures by the plate 4 inclined relative to cables 300 and 310 shown in lines discontinuous, these two cables being in fact always vertical. In this case, we sees that the levers 520 and 530 can tilt according to the arrows A, controlling the clamping of the jaws 500 and 510 as described above, respectively stopping the vehicle or the nacelle. So the system such as described, allows a safety stop in the event of a malfunction of the winches.

Variants of execution or construction can be envisaged in relation to the examples mentioned above; for example the plate 4 carrying the braking device has been described as being connected to the nacelle by a set of slides 40 and 41 or by links 47. Any means mechanical ensuring relative movement between the plate 4 and the carrycot can be used. Likewise the transmission between the strand detector slack 52 or 53 and the braking device 50 or 51 has been described in a form preferential execution; other constructive provisions than those described can be used producing the same effect.

The damping device as well as the braking device have been described as being mounted on a nacelle intended for maintenance of facades; more generally such devices can be mounted to operate as described, on any vehicle, charges or object pulled by at least one pair of cables whose tensions are equivalent, such as cable cars, funiculars, elevators, freight elevators or elevators. By vehicle is also meant any mobile system, without it is necessary for this system to transport a person.

It is obvious that the described damping device can be mounted on a vehicle fitted with an emergency braking device other than that described above, the damping device can even work from the as described when the vehicle or load is towed or suspended by a single cable. Likewise, the described emergency braking device can be mounted on a vehicle without a damping device or a damping device different from one of those described above.

Furthermore, the different execution variants mentioned above have been described as being driven by one or two winches comprising one or two synchronized winding drums. The man of profession will adapt both the braking device and that amortization to any other configuration of winch, drums, pulleys, possibly mechanically or electrically synchronized.

Claims (17)

1. An emergency braking device (5) capable of acting on a vehicle or load (1) drawn or secured by at least two cables (30, 31) or strands of the same cable whose tensions under normal operating conditions are equivalent,
   characterised in that it comprises:

   a first device (52) for detecting a slack strand or lack of tension in a first cable (30), capable of controlling a first braking means (51) acting only on a second cable (31), and

   a second device (53) for detecting a slack strand or lack of tension in said second cable (31), capable of controlling a second braking means (50) acting only on said first cable (30).
2. A braking device according to Claim 1, characterised in that the transmission of control between the slack strand or lack of tension detector (52, 53) and the associated braking means (51, 50) is carried out only by mechanical means (520, 523, 513, 530, 533, 503).
3. A braking device according to Claim 2, characterised in that each slack strand or lack of tension detection device (52, 53) comprises a first lever (520, 530), one end of which comprising a small support wheel (522, 532) is pressed by a spring means (516, 506) against the cable to be checked (30, 31), the other end of said lever acting on a second pivoting lever (513, 503) capable of keeping two braking jaws (500, 510) in a loose position around the cable on which the braking is carried out, the release of the support exerted by the cable to be checked allowing the swinging of said first lever and of the pivoting lever, leading to the gripping of the two jaws against the cable to be braked, under the action of said spring means.
4. A braking device according to Claim 3, characterised in that at least one of said first levers (520, 530) is arranged in such a way that an inclination of the braking device (5), respectively of the vehicle (1) to which it is fixed, beyond a given value, leads to activation of the associated braking means.
5. A vehicle or load (1) drawn or secured by at least two cables (30, 31) whose tensions under normal operating conditions are equivalent, characterised in that it comprises at least one emergency braking device (5) according to one of Claims 1 to 4.
6. A vehicle or load (1) according to Claim 5, characterised in that it also comprises at least one shock absorbing device comprising at least one shock absorber (43, 44, 48, 49, 62) disposed between a plate (4) and a fixed portion (430, 440, 450, 63) of the installation.
7. A vehicle or load (1) according to Claim 6, characterised in that said fixed portion of the installation corresponds to a portion (430, 440, 63) of the vehicle or load.
8. A vehicle or load (1) according to Claim 6, characterised in that said fixed portion of the installation corresponds to a portion (450) of the fixed environment of the vehicle or load.
9. A vehicle or load (1) according to one of Claims 6 to 8, characterised in that the shock absorber or shock absorbers (43, 44, 62) are provided for working in compression in the case of operation of the emergency braking device.
10. A vehicle or load (1) according to one of Claims 6 to 9, characterised in that at least one of the shock absorbers is a hydraulic shock absorber.
11. A vehicle or load (1) according to one of Claims 6 to 9, characterised in that at least one of the shock absorbers is a spring shock absorber.
12. A vehicle or load (1) according to one of Claims 6 to 9, characterised in that at least one of the shock absorbers is an elastomer pressure shock absorber.
13. A vehicle or load (1) according to one of Claims 5 to 12, characterised in that said emergency braking device (5) is mounted on a plate (4) comprising means (40, 41, 45, 47) of fixing to the vehicle, capable of allowing a relative motion between the plate and the vehicle, essentially in the direction of motion of said vehicle, the amplitude of said relative motion being limited.
14. A vehicle or load (1) according to Claim 13, characterised in that the fixing means are channel and guide slot means (40, 41, 45).
15. A vehicle or load (1) according to Claim 13,
    characterised in that the fixing means comprise link rods (47) forming a deformable parallelogram.
16. A vehicle or load (1) according to one of Claims 5 to 15, characterised in that said plate (4) comprises in addition the winch or winches (2) for winding or unwinding said cables or a return pulley (23) for said cable.
17. A vehicle or load (1) according to one of Claims 5 to 16, characterised in that it consists of a building frontage maintenance cradle (1).

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