Protective device for a helicopter equipped with a winch, winch equipped with such a device, and helicopter equipped with such a winch

Abstract

This device for protecting a helicopter equipped with a winch (2) and a lifting cable (6) against the consequences of a sudden break in said cable, the winch being equipped with an exit hole (5) for the cable (6), consists of a screen (7) positioned in the vicinity of the exit hole (5) of the cable (6) or deployable in the vicinity of the exit hole (5) of the cable (6), said screen being oriented substantially perpendicular to the direction of said exit hole and extending over a distance of at least 20 centimeters from said exit hole. Figure for the abbreviation: Fig 3

Description

Description Title of the invention: DEVICE FOR PROTECTING A HELICOPTER CARRYING A WINCH, WINCH EQUIPPED WITH SUCH A DEVICE AND HELICOPTER CARRYING A SUCH WINCH Scope of the invention

[0001] = The invention relates to the field of lifting devices, more particularly carried on aircraft, particularly helicopters. In addition to aspects of The invention aims to rescue individuals using helicopters equipped with a winch. also the transport of people or cargo, always by helicopter, particularly in places difficult to access by other means (wind turbines, ships) the approach to the ports, …). Prior state of the art

[0002] — The implementation of winches mounted on aircraft, and more specifically helicopters are now widely used. Typically, a winch is mounted within the helicopter, and the cable of said winch, is unwound as needed.

[0003] While such onboard winches, particularly within helicopters, have largely demonstrated Despite their effectiveness, there are situations where their use can prove dangerous. particularly for the helicopter and consequently for its occupants.

[0004] — By regulation, the winch must be equipped with means capable of cutting said cable at the winch or cab level when, in the presence of critical conditions, such such as an engine failure of the helicopter during a winching operation, for example, The crew needs, for the safety of the helicopter, to cut said cable.

[0005] It also happens that during a winch operation, the cable becomes jammed in a obstacle (pylon, tree, etc.) requiring activation by the crew of said means of sectioning.

[0006] — However, in certain cases of jamming, in the event of a sudden overvoltage or Overvoltage associated with localized cable damage due to a sharp edge For example, the cable might break before the crew can react. In this case The cable is severed at a non-negligible distance from the helicopter.

[0007] During such occurrences, due to the tension exerted on the cable, it is observed that… by the load it carries or by the helicopter, an elastic effect tending to make it rise abruptly the severed end of the cable and the cable itself in the direction of the helicopter. In doing so, the cable is likely to reach the helicopter's blades, and can therefore generate effects that could lead to the helicopter crashing, with the catastrophic consequences that result in terms of occupant safety the helicopter, in addition to, where applicable, the location where said helicopter crashed. To overcome this significant drawback, it is possible to use cables that are oversized relative to the load they are designed to lift. This increases their mass and, consequently, limits cable lift due to the elastic effect inherent in the tension to which they are subjected. By doing so, the risk of the cable end rising above the winch level is avoided. However, using such heavier cables necessitates a more powerful and also heavier winch, which is precisely what winch designers aim to prevent. The object of the invention is to overcome these various drawbacks by proposing a device that is simple to implement and meets safety requirements. Description of the invention To this end, the invention aims at a device for protecting a helicopter carrying a winch against the consequences of a sudden break in the cable of said winch, whether said break is accidental or intentional, said winch being equipped with a cable exit hole. According to the invention, this device comprises a permanent screen fixed near the cable exit port or deployable near the cable exit port. This screen is advantageously oriented substantially perpendicular to the direction of said exit port; it is intended to extend the protection area of ​​the helicopter resulting from the winch itself, and in particular from the protective cover with which said winch is equipped, by a distance of at least 20 centimeters measured from said exit port. In other words, the invention consists of equipping the winch with a screen or shield, capable of receiving the cable strand in the event of an elastic return of the latter following a sudden break, and capable of opposing the protrusion of said cable strand beyond said winch, and in particular beyond the protective cover of the winch, and thus preventing it from winding up and, in general, interfering with the blades of the helicopter. Experience shows that with a screen or shield typically extending a minimum of 20 centimeters, and advantageously between 20 and 50 centimeters beyond the cable exit point from the winch, any risk of the cable strand exceeding the winch, and therefore in the direction of the blades, is avoided, thus ensuring the safety of the helicopter equipped with the winch in question. In a first embodiment, this screen is rigid and permanently fixed near the cable exit point. This screen can thus be made of a metal sheet with sufficient rigidity to absorb the shock inherent in the sudden upward movement of the cable end in the event of a break. It can also be made of a rigid composite material plate, or even a plastic plate. In another embodiment, the screen consists of a mesh or perforated grid, secured near the winch outlet by means of a rigid rod or equivalent. This design reduces the helicopter's lift due to the perforated nature of the mesh or grid. According to yet another embodiment, the screen is deployable in the vicinity of the cable exit hole from the winch, like an airbag. The invention also relates to a helicopter equipped with an onboard winch, in which the winch is mounted on a rotating gantry to allow the winch to operate, the winch in question being equipped with the aforementioned device. Brief description of the figures The manner in which the invention can be implemented and the resulting advantages will be better illustrated by the following implementation examples, given by way of example and not limitation, in support of the attached figures. [Fig.1] is a schematic view of a helicopter equipped with a winch. [Fig.2] schematically illustrates a winch equipped with its cover. [Fig.3] illustrates the winch of [Fig.2] equipped with the device according to a first embodiment of the invention. [Fig.4] is a side view of the winch from [Fig.3]. [Fig.5] illustrates the winch of [Fig.2] equipped with the device according to a second embodiment of the invention. [Fig.6] is a side view of the winch from [Fig.5]. [Fig.7] illustrates the winch of [Fig.2] equipped with the device according to a third embodiment of the invention. Detailed description of the invention A helicopter (1) with its rotor blades (4) is illustrated in relation to [Fig. 1]. This helicopter includes a winch (2) mounted on a removable boom (3). The boom is designed to allow the winch to be extended from the helicopter cabin for operational use. Such a boom, which can also be fixed, is a known feature, and therefore does not require further description. According to the invention, the winch typically consists of a storage and / or lifting drum, or even a capstan associated with a storage drum. It is operated by means of one or more electric motors, depending on whether the winch comprises solely a storage and lifting drum or a storage drum and a capstan, the pulling force then being provided by the capstan itself. The advantages of such a capstan winch are also widely known, so there is no need to describe them in detail here. Whether said winch comprises a simple storage drum and / or a storage and lifting drum, it comprises an exit port (5) of the cable (6), at the end of which a load or an individual (11) is intended to be lifted. According to a feature of the invention, a sheet metal plate (7) is positioned in the vicinity of this exit orifice (5) of the cable (6), and more particularly slightly above this orifice, and according to a first embodiment of the invention, attached by any means to said winch, the latter being equipped with capabilities, of the type of tapped orifices suitable for allowing the fixing by screwing of the sheet metal. In this case, this metal plate (7) extends substantially perpendicularly to the main direction of the winch (6) exit opening (5), over a distance of at least 20 centimeters, and advantageously between 20 and 50 centimeters from said cable exit opening. In the example described, since said cable exit opening (5) is not centered with respect to the overall cylindrical volume of the winch, but offset, as can be seen in Figures 4 and 6, the plate (7) extends only in the left-hand direction in said figures, the winch cover ensuring the function of stopping the end of said cable on the other side. This sheet metal is relatively rigid to allow the cable to stop in the event of a sudden break and its rebound by elastic effect towards the helicopter, and to resist vibrations while offering minimum air resistance both in the direction of the helicopter's forward movement and in the vertical direction to minimize the loss of lift generated by the rotor (blades 4). As can be seen in the figures, this sheet metal (7) is fixed to the periphery, or even slightly above the outlet opening (5) so as not to hinder the raising and lowering of the cable through said opening (5). This sheet metal (7) can be replaced by a rigid plastic plate. Alternatively, and as illustrated in Figures 5 and 6, this sheet metal (7) can be replaced by an added surface (8), typically consisting of a wire mesh or grid, held in the plane in which this protective device extends by a rigid beam or rod (9) extending from the winch. This embodiment has the advantage of reducing the load-bearing capacity reduction resulting from said device. According to yet another embodiment of the invention, this protective device is deployed only when a sudden break in the cable (6) is detected. This detection can, for example, be measured by the instantaneous determination of the torque exerted on the lifting drum or the capstan forming part of the winch assembly. According to this embodiment, the protective device is, in normal operating mode, retracted inside the winch in a housing provided for this purpose, and protected by a cover (10) of appropriate dimensions, and deploys ex- extremely quickly by means of pyrotechnical means for example, such as an airbag, as soon as a sudden break in the cable is detected (6). In this configuration, an inflatable tube unfolds, according to a plane analogous to that in which the sheet metal (7) of the first embodiment described is inscribed, a net being stretched concomitantly in the interior of the surface then defined by said tube. By implementing such a protective device, the Applicant was able to observe that, regardless of the tension exerted on the cable at the time of its sudden break, which could cause it to rise abruptly, the cable strikes the underside of the device without exceeding the plane in which the device is located, and therefore without risk of the broken cable getting caught in the helicopter blades. The full benefit of the present invention is clear: using a simple-to-implement device, it eliminates any risk of the cable becoming entangled in the helicopter blades, thereby optimizing the safety of the helicopter and its occupants.

Claims

Demands

1. Protective device for a helicopter (1) carrying a winch (2) equipped with a lifting cable (6) against the consequences of a break abrupt cut of said cable, the winch being equipped with an exit port (5) of the cable (6), characterized in that said device consists of a screen (7, 8, 9) positioned in the vicinity of the exit port (5) of the cable (6) or deployable in the vicinity of the exit port (5) of the cable (6), said screen being oriented approximately perpendicular to the direction of said outlet and extending over a distance of minus 20 centimeters from said outlet opening.

2. Protective device for a helicopter according to claim 1, ca- rafted in that the screen extends over a distance between 20 and 50 centimeters from the cable exit hole (5) out of the winch.

3. Protective device for a helicopter according to one of the claims 1 and 2, characterized in that the screen is made of a metal sheet of sufficient rigidity to absorb the shock inherent in the ascent sudden breakage of the cable end in case of rupture.

4. Protective device for a helicopter according to one of the claims 1 and 2, characterized in that the screen is made of a plate made made of rigid plastic.

5. Protective device for a helicopter according to one of the claims 1 and 2, characterized in that the screen consists of a net or grid perforated, secured near the winch's exit opening by means of of a rigid rod or equivalent.

6. Protective device for a helicopter according to one of the claims 1 and 2, characterized in that the screen consists of an inflatable tube combined with a net, the assembly thus defined being received in a housing dedicated within the winch, and not being deployed under the action of pyro- means techniques that, when a sudden break in the cable (6) is detected, the inflatable tube then defining a surface oriented substantially perpendicular to the direction of said outlet orifice and within which a net is stretched simultaneously with the de- folding of said sausage.

7. Lifting winch equipped with a lifting drum or a capstan on which is wound around a cable (6) to the end of which is fixed a charge (11), and incorporating a motor capable of ensuring the rotation of the drum lifting device or capstan, equipped with a protective device according to one claims 1 to 6.

8. 'Winch according to claim 7, comprising a break detector brutal cable (6).

9. 'Winch according to claim 8, wherein the break detector The abruptness of the cable is measured by a sensor measuring the torque exerted by the cable (6) on the lifting drum or on the capstan.

10. Helicopter equipped with a winch according to any one of claims 7 to 9.