A WHEELED TRANSFER DEVICE FOR MOVING AN AIRCRAFT

Abstract: The object of the invention is a transfer device equipped with support wheels (4) to move an aircraft (1) or other device equipped with double wheels (6) over a base (2), which transfer device includes at least one so-called self-wedging friction roller (3) which grips the wheels (6) of the device to be moved beneath their axles, and two support wheels to drive at essentially the same peripheral velocity in the opposite direction, and in which transfer device these two driving support wheels (4) are located close to the line of the friction roller (3). The transfer device in accordance with the invention includes a pushing section (12) with its own wheels, power source, drive and steering devices, and that the friction rollers and driving support wheels are located in a transfer unit (9), which is connected to the pushing section (12) by means of a boom (11), which is connected to the transfer unit (9) by means of a vertical joint (10) and to the pushing unit (11) by means of a horizontal joint (13).

Description: A Wheeled Transfer Device for moving an Aircraft The object of the invention * is a transfer device equipped with wheels for moving an aircraft or other wheeled device over a base, which transfer device includes at least one so-called self- wedging friction roller which presses onto the wheels of the device to be moved, beneath their axles, drive devices to drive the friction roller and two support wheels at essentially the same peripherical velocity in different directions, and in which transfer device these two driving support wheels are located close to the centre line of the friction roller. Here double wheel also means two neighbouring wheels of a bogie and friction roller also means a friction track. The transfer of aircraft on an airfield usually takes place using tug tractors, which must be constructed heavily, so that they will have the necessary tractive capacity. The construction of a transfer device can be essentially lightened when the driving force is transferred to the ground wheel of the aircraft from a drive wheel or friction roller belonging to the transfer device. This presupposes that the friction roller is pressed against the aircraft ground wheel which such a force that is usually a few percent of the weight coming onto the wheel. This invention is especially connected to transfer devices equipped with so-called self-wedging friction rollers, which are known, for example, from the following patent publications, SE 437137, GB 845,105, SU 425527, and US 4,125,029 and from Finnish Patent Application 870710. The transfer device shown in the US publication differs considerably from the two previously mentioned in that it is only applicable to pulling the device to be moved. In the two first as in this invention the question is one of a transfer device equipped with a pushing friction roller. In these the aforementioned compressive force is created by the combined effect of a turning moment and the transfer device's own driving support wheels. The known devices demand either good friction conditions or they must be located very low down, which causes difficulties in construction. A small friction roller can always be placed quite low down, but the surface pressure on the ground wheel then easily becomes greater than that permitted. The known devices are poorly adapted to moving aircraft equipped with double wheels. For example a transfer device in accordance with the GB publication does not permit the aircraft to turn when the double wheels would rotate at-different speeds. The intention of this invention is to create a new transfer device equipped with a so-called self-wedging friction roller, which can operate under very much poorer friction conditions than earlier devices, in which case the transfer device can operate when the friction roller is even quite high in relation to the axle of the ground wheel of the device to be moved. The principal characteristics of the invention appear in the accompanying Patent Claim 1. The main principle of the device is to use the transfer device to multiply the pushing power. Under typical conditions a coefficient of 10 - 15 can be achieved. Then for example the 1 tn (10 kN) push of a small tractor acting as a pusher multiplies to 10 - 15 tn, which power is enough to move very large aircraft. By means of the invention in accordance with Patent Claim 2 the intention is to create a transfer device especially intended to move devices with double wheels, which permits the device being moved to turn, when the double wheels rotate at different speeds. The forms of application in accordance with Patent Claims 3 - 5 are technically very advantageous. The form of application in accordance with Patent Claim 6 makes it possible to use a small tractor as a pusher, in which case the transfer unit and boom form a detachable separate accessory. In a transfer device in accordance with Patent Claim 7 the steering is implemented in its own movement advantageously by turning the transfer unit in relation to the boom. In what follows the invention is illustrated by means of an example by reference to the accompanying figures in which Figure 1 shows the transfer device seen from above Figure 2 shows the situation in Figure 1 seem from the side. The transfer device shown by Figures 1 and 2 is intended for moving an aircraft 1 on an airfield 2. In the figures aircraft 1 is shown as only a part of the undercarriage and ground wheels 6. The principal components of the transfer device are the transfer unit 9 itself and the pushing section 12 and the boom 11 that connects them. The pushing section is advantageously a small tractor, when the transfer unit 9 and the boom 11 form a detachable accessory. The transfer unit 9 is connected to the boom 11 by means of a vertical joint 10, which makes it possible for the aircraft 1 to turn while being pushed. The springs 22 return the transfer unit 9 to a central position after possible deviation. The transfer unit 9 is constructed on a frame, to which two sleeve axles 23 are attached by bearings on each side of the same line, these are combined by a common main axle 16, round which both sleeves are free to rotate. Simple journal bearings are adequate here, because the friction rollers generally rotate at the same speed. Friction roller 3 is permanently attached to sleeve axle 23 and support wheel 4 is attached to it by a bearing. The hydraulic motors 5 with gearboxes are attached to the frame and their axle forms the drive axle 20, on which there is the drive toothwheel 17 and drive chainwheel 19. These form part of the gearwheel drive 7, by means of which drive is transmitted to the support wheel 4, and of the chain drive, by means of which drive is transmitted to the friction roller 3. The driven toothwheel 18 is attached to support wheel 4 and includes a centre hole through which sleeve axle 23 runs. The driven chainwheel 23 is attached to the sleeve axle 23 itself. High-pressure hydraulic oil is produced in the pump unit in the tractor. The figures do not show the hydraulic connection between the transfer unit and the tractor. By using parallel toothwheel 7 and chain transmission 8 moment in different directions in the friction rollers 3 and support wheels 4 are created simply, however, the peripheral velocities remain of the same absolute value. Figure 2 shows the connection of the transfer unit 9 to the pushing unit 12. The boom 11 that transmits the push is connected in a horizontal direction by means of joint 13 to pushing unit 12, which thus permits the transfer unit to move in accordance with the form of the surface of the airfield. In order that the transfer device can be brought rapidly close to an aircraft 1 and taken away from it, the transfer unit 9 can be slightly raised off the ground by means of the jointed auxilliary arm 14. The auxilliary arm 14 includes operating device 15, by means of which it can be retracted so that the transfer unit 9 and with it the support wheels 4 can be lifted off the base 2. The pushing section and the transfer unit can naturally also be constructed as a single unit. The pushing unit is then equipped with only two drive wheels and operating devices, by means of which the transfer unit can be turned in order to steer the .transfer device.

Claims: Patent Claims 1. A transfer device equipped with support wheels (4) for moving an aircraft (1) or other device equipped with double ground wheels (6) over a base (2) , which transfer device includes at least one so-called self-wedging friction roller (3) that takes hold of the ground wheels (6) of the device to be moved beneath their axles, drive devices to rotate the friction roller (3) and two support wheels (4) at essentially the same peripheral velocity in different directions, and in which transfer device these two driving support wheels (4) are located close to the axle line of the friction roller (3) , characterized in that the transfer device includes a pushing section (12) equipped with wheels and devices to drive them, and that the friction rollers and driving support wheels (4) are located in a transfer unit (9) , which is connected to the pushing section (12) by means of a vertical joint (10) . 2. A transfer device in accordance with Patent Claim 1, characterized in that the transfer device includes two friction rollers (3) , which are equipped with separate devices to rotate them (7, 8) and by means of which it is possible to separately rotate the double ground wheels (6) of the device (1) to be moved. 3. A transfer device in accordance with Patent Claims 1 or 2 characterized in that both the friction roller (3) and the driving support wheel (4) are located on the same axle (16, 23). 4. A transfer device in accordance with Patent Claim 3, characterized in that that both the sleeve axle (23) , which is joined to the transfer unit (9) frame, and one friction roller (3) and the wheel (20) driving it, that form part of the transfer device, are permanently locked to this sleeve axle (23) and that the driving support wheel (4) is attached to this sleeve axle (23) by bearings. 5. A transfer device in accordance with Patent Claims 3 or 4 characterized in that both the driving devices (7, 8) include toothwheel (7) and chain drive (8) transmission between the aforementioned axle (16) and drive axle (17) , in which the driving toothwheel (17) and chainwheel (19) are permanently located on the drive axle (20) , and in which one of the driven wheels (18, 20) is placed in permanent connection to the friction roller (3) and the other in permanent connection to the support wheel (4) and in which case the transmissions (7, 8) form the aforementioned peripheral velocities in different directions. 6. A transfer device in accordance with one of the above Patent Claims 1 - 5, characterized in that the transfer device includes a boom, by means of which the transfer unit (9) is connected to the pushing section (12) , and that the boom (11) is connected to the transfer unit (9) by means of the aforementioned joint (10) and to the pushing unit (12) by means of a horizontal joint (12) . 7. A transfer device in accordance with one of the above Patent Claims 1 - 5, characterized in that the transfer device includes an operating device to turn the transfer unit (9) and thus to steer the entire transfer device.

Inventors: SINKKONEN MATTI, SINKKONEN, MATTI
Applicants: TANA JYRAE KY, TANA-JYRAE KY
Application year: 1990
Main classification: B60S13
IPC codes: B64F1