FI75535B - MED HJUL FOERSEDD FLYTTNINGSANORDNING FOER FLYTTNING AV ETT FLYGPLAN. - Google Patents

Description

75535

Wheeled transfer device for moving an aircraft

The invention relates to a wheeled transfer device for moving an aircraft on a base, which transfer device comprises at least one wheel which can be pressed under the wheel 5 of the aircraft to be moved, so-called a self-wedge friction roller, which is rotated upward from the point of contact to move the aircraft, and the transfer device includes rotation roller rotation devices. The transfer device is also generally intended for transferring different wheeled vehicles. By friction roller 10 is also meant here a set of rollers or a roller mat placed on the same side.

Traction tractors are usually used to move aircraft at airports, which have to be built to be heavy in order to have sufficient traction capacity. As the IS size of airplanes grows, all you need is always larger tractors with heavy construction, big wheels, powerful brakes, sturdy axles.

The structure of the transfer device can be substantially lightened when the rotational force is transferred to the aircraft's own wheel 20 from the drive wheel, i.e. the friction roller, belonging to the transfer device. This requires pressing the drive wheel against the wheel of the aircraft with a force that is usually a few percent of the weight entering the wheel. The most common solution in connection with such transfer devices is that the transfer device 25 is fastened by means of suitable members to the bogie or shaft ends of the aircraft in order to provide a compressive counterforce. Such transfer devices cannot be used to transfer any type of aircraft, as the airframe must have corresponding counterparts to allow the transfer device 30 to be engaged. A fully general purpose light transmission device structure is presented in Finnish patent application FI 833275 (partly corresponding to WO85 / 01265). This does not require any contact from the aircraft bogie to press the drive wheel against the wheel. The compression is provided by the mutual displacement of the intermediate-connected compression wheels placed around the wheel 35 of the aircraft.

This invention relates in particular to the so-called for self-wedge friction roller transfer devices known, for example, from the following patents 2 75535 SE 437137, GB 845,105 and US 4,125,029. The transfer device disclosed in the U.S. publication differs considerably from the above two, in that the transfer device disclosed therein is only suitable for towing a vehicle to be transferred. The first two, as in the present invention, are transfer devices with a pushing friction roller. In these, the above-mentioned compressive force is obtained by the combined action of the torque and the transfer device's own support wheels. The friction roller tends to pull itself under the wheel of the aircraft, whereby the horizontal forces of the compressive force and the tangential frictional force cancel each other out, but in the vertical direction they produce a double resultant force which the transmission's own wheels have to carry.

The problem with transfer devices-15 roads with pushing friction rollers is e.g. the fact that the aircraft to be moved may suddenly run away from the grip of the friction roller. This is due, for example, to irregularities in the field. This detachment may also be due to the difficulty of known wedge transfer devices in tracking the aircraft. Known transfer devices need to be constantly controlled to keep them attached to the aircraft wheel. Of course, the lack of a pulling possibility or, in the case of the above-mentioned US publication, the lack of a pushing possibility can also be regarded as a disadvantage.

The object of the present invention is to provide a new so-called

a transfer device with a wedge friction roller with the above-mentioned problems has been eliminated. The main features of the invention are clear from the appended claim 1. According to the invention, the locking roller is not compressed, whereby it preferably comes into contact only if the friction roller loses its grip on the aircraft wheel or the transfer device is inclined. The embodiment according to claim 2 shows a simple transfer device solution which is suitable for both pushing and pulling an aircraft. Here, the "traction" is actually provided by means of a pushing friction roller. It should be noted that here only one of the friction wheels can always transmit torque to the aircraft wheel. Even if the friction roller on the driving side is in contact with this wheel, it can practically not transmit any transmission power at all, since the compressive force is in any case low.

3,75535

The embodiment according to claim 3 significantly improves the control effect of the transfer device. The design of the rollers achieves two significant advantages. Firstly, the above-mentioned improvement of the own control of the transfer device, whereby it remains reliably attached to the wheel of the aircraft, on the other hand, the compression pressure is more evenly distributed on the surface of the wheel of the aircraft. The rollers of the one-wheel-engaging transfer device are preferably shaped according to claim 4, which guarantees reliable self-steering.

In the following, the invention will be illustrated by way of example with reference to the accompanying figures, in which

Figure 1 shows a top view of the transfer device

Figure 2 shows the situation according to Figure 1 seen from the side. Figure 3 shows the principle of forming the rollers in a transfer device adhering to one wheel.

The transfer device shown in Figures 1 and 2 is intended for transferring the aircraft 1 at the airport 2. Figures 1 show only a part of the landing gear and the wheels 6. The transfer device is provided with its own traction, which is switched off when the traction is transmitted to the aircraft wheel. The transfer device is driven around the twin wheels 6 of the aircraft 1 with the front friction rollers pulled aside. In the position 25 and 2 of Figures 1, the transfer device is pushing the aircraft 1, i.e. the rear friction rollers 3 are in operation. The direction of rotation of the driving friction roller and its point of contact as previously described are very essential for the operation of the transfer device.

The front friction rollers 4, i.e. in this situation the rollers of the latch-30 are not in contact with the wheel 6. However, if the traction friction roller 3 loses its grip on the wheel 6, the locking roller 4 prevents this from escaping completely. On the other hand, if the transfer device drifts slightly obliquely to the twin wheels 6, the latch roller also comes into contact with the wheel 6 at its edge and 35 returns the transfer device to the correct position. When the transfer direction is changed, the front friction rollers are brought into contact with the wheel 6, and their rotation is started. Functionally, the rear friction rollers 3 now act as latch rollers.

75535

A

If the transfer device rotates twin wheels, the maneuverability is inherently good. To ensure that the transfer device stays in place, the rollers only need to be slightly thinned in the middle to prevent direct lateral movement. In the case of a single-wheel drive transfer device, the situation is more complicated. Figure 3 shows a horizontal cross-section at the rollers. This is where the principle of cost-effective design comes into play. The transfer device tends to rotate around the wheel 6. By now drawing a circle 5 with the diameter of the wheel 6 obtained from the center position 10, it can be seen that this is the loosest position. The edges of the rollers 3 and A resist rotation and thus return the transfer device to the center position if it is tilted. As the entire aircraft turns, the transfer device follows with a slight oppression, ib 20 25 30 35

Claims (4)

5,75535 A wheeled transfer device, in particular for transferring an aircraft (1) on a base (2), the transfer device comprising at least one wheel (6) to be pressed under the axis of the mobile aircraft (1), so-called a self-propelled friction roller (3), which is rotated upwards from the point of contact to move the aircraft (1), and the transfer device comprises rotating devices for the friction roller (3), characterized in that the transfer device comprises a locking roller (4) to prevent escape and / or to stabilize the transfer, which latch roller is normally adapted to be either completely detached or only at a slight pressure on the wheel (6) of the aircraft (1). 2. claimed in claim 1, the transmission device, characterized in that the bolt frame (4) is substantially symmetrically disposed second friction roller 20, and a shifting means comprises devices for coupling the diverging rotation, alternatively, either one side of the friction roller (3,4). Transfer device according to Claim 1 or 2, characterized in that both the friction roller (3) and the latch roller (4) are self-centering, i.e. their edge diameters are substantially larger than the central diameters and their shape is thus adapted to the wheel (1) of the aircraft (1) to be moved. 6) that the position of the slack is with the wheel (6) of the aircraft (1) directly between them, whereby they retrieve 30 back to the middle position after being oblique due to a disturbance. Transfer device adhering to one wheel (6) according to Claim 3, characterized in that the shapes of both the friction roller (3) and the locking roller (4) are arranged in the middle on the edges 35 so that in the cross-section of the operating position, i.e. in both diameters (3,4). in the section, the projection edge line of the rollers (3,4) at the edges remains largely inside a circle (d) whose diameter (d) is the diameter of the ring (6) in this cross section.