WO1988005400A1

WO1988005400A1 - A device for moving an aircraft

Info

Publication number: WO1988005400A1
Application number: PCT/FI1988/000008
Authority: WO
Inventors: Jouni Heikki Ilari Hirvonen; Kari Ensio Laitinen
Original assignee: Tana-Jyrä Ky
Priority date: 1987-01-26
Filing date: 1988-01-25
Publication date: 1988-07-28
Also published as: FI74922C; FI74922B; JPH02501915A; AU1182188A; FI870313A0

Abstract

A transfer device (2) for moving an aircraft (1), which transfer device (2) consists of a friction roller (3) to be brought into contact with the wheel (6) of the aircraft (1), a device to turn it and compression devices to press the roller (3) against the wheel (6) of the aircraft (1), when by turning the roller (3) the aircraft (1) is made to move. The object of the invention is to prevent the formation of ice on the surface of the friction roller, which would cause slipping. A transfer device (2) in accordance with the invention includes snow removal members (5) to remove snow from the wheel (6) of the aircraft (1) and/or its path (7). In practice it has been noticed that especially light dry frozen snow adheres lightly at first to the aircraft's wheel, but that it then forms under compression a layer of hard ice on the surface of the friction roller.

Description

A Device for moving an Aircraft

The object of the invention is a device for moving an aircraft, the device consisting of a friction roller (3) to be brought into contact with at least one wheel of the aircraft, a means of turning it, and a pressure device to press the roller against the wheel of the aircraft, so that when the roller is turned it causes the aircraft to move. The invention is especially concerned with the winter operation of the transfer device. The construction of an entirely generally applicable light transfer device is presented in the Finnish Patent Application FI 833275 (in part corresponding W085/01205). This demands no contact with the bogie of the aircraft to press the drive wheel against the aircraft wheel. The pressure is achieved by means of the mutual 'movement of two pressure rollers connected by an intermediate device and placed round the wheel of the aircraft. Another corresponding solution is presented in the Finnish Patent Application FI 861714• Other :pubIieaιfiiiσr_E. belonging to the field of this invention and which present such transfer devices in which this invnetion may be adapted, are among others the following: US 3,025,922, 3,005,509. 3,005,510, 3,025,922, SE437 137, and GB 845.105. Problems of the winter operation of the transfer devices are not recog¬ nized, nor are typical problems of winter operation dealt with in any of the aforementioned publications. The point of departure of this in¬ vention is the problem of the icing-up of the friction roller, which has been observed in practice, in which in especially hard frost the friction roller begins to collect ice on its surface, causing slip. At such times only some light dry frozen snow appears at the airfield.

It is the intention of this invention to prevent the formation on the friction roller of the ice that causes slipping. In practice it has been observed that light dry frozen snow in particular adheres at first lightly to the aircraft wheel, but that in then forms a layer of hard ice on the surface of the friction roller when it is compressed. With the aid of the invention the aforementioned new problem is removed. The principal characteristics of the invention appear in the accompanying Patent Claim 1. The main principal of the invention is to remove the snow before it reaches the point of compression. A surprising observation was the fact that there were no benefit at all in brushing the friction roller, for the ice becomes hard suddenly and grips tightly a concrete friction roller for example. According to observations the ice is formed from light dry frozen snow, which forms ice under compression.

The forms of construction in accordance with Patent Claims 2 and 3 are technically simple, and in these the brush devices used can be advantage¬ ously placed under a fixed friction roller, where they will in no way hinder operations. In the form of construction in accordance with Patent Claim 4 the snow is removed at a still earlier stage^ i.e. from the path of the aircraft wheel when its removal is possible with very light brush- ing. Patent Claims 5 and. 6 present still other advantageous forms of appli¬ cation,- in which the snow is removed by means of a blast of air.

In what follows the invention is illustrated by means of examples by refering to the accompanying illustrations, which present various forms of application of the. invention.

Figure 1 shows the transfer device in its operating position viewed from above. Figure 2 shows a transfer device in accordance with Figure 1 viewed from the side in partial cross-section. Figure 3 shows another transfer device in its operating position viewed from above. Figure 4 shows the situation in accordance with Figure 3 viewed from the side. Figure 5 shows a third transfer device in its operating position viewed from above^".

The transfer devices 2 shown in Figures 1 -5 are intended to move the aircraft 1 on an airfield. In the figures the aircraft 1 is shown as only a part of the landing gear and the wheels 6. The transfer device 2 moves to the aircraft driven by its front wheels, and in addition to them its principal components are the pressure wheels i.e. friction rollers 3 and 4 attached to the frame, the power unit, and the steering device that turns the rear wheel. Both wheels 6 have their own friction rollers 3 and 4> In the manner known from the aforementioned publications the front frietionn nolQiers-- 4 both turn to the side and move in a longitudinal di¬ rection. When the transfer device 2 is driven up to the wheel 6 the-front friction rollers are naturally turned to the side. After this the com¬ pression required for power transmission is achieved by means of them and friction rollers 3 and 4 begin to turn. These transfer devices are mainly intended to push aircraft, because the various snow removal de¬ vices are arranged only for pushing. Otherwise they are also suitable for pulling aircraft. Beneath the rear friction rollers 3 in Figures 1 and 2 are located the revolving brushes 5« These are driven through gearbox 9 from the drive device of the friction rollers 3. When pushing an aircraft 1 on a snowy airfield the snow adheres to its wheel 6. The snow is now removed from it by the revolving brush 5 and the first compression point at the friction roller 3 remains clean. There are also no problems with the second compression point at roller 4-

In the transfer device 2 in Figures 3 and 4 the path 7 of the wheels 6 of the aircraft 1 is kept clean of snow by sweeping it to the side by means of the brushes 5'. At this stage the snow is completely untouched and can be very lightly moves to the side.

In the transfer deice 2 of Figure 5 there are compressed air devices and a nozzle 8, by means of which snow is removed from the wheel's path. The invention can also be arranged in other ways within the framework of the Patent Claims. In place of the revolving brush of Figure 2 either a completely stationary brush or vibrating brush can advantageously be used, both of which required less space than a revolving brush. The move¬ ment of the vibrating brush can be advantageously taken from the roller.

Claims

Patent Claims

1. A transfer device (2) for moving an aircraft (l), which transfer device (2) consists of a roller (3) brought into contact with at least one wheel (6)- of the aircraft (1), a device to turn it and a compression de¬ vice to press the roller (3) against the wheel (6) of the aircraft (l), when by turning the roller (3) the aircraft (1) is made to move, characteriz ed in that the transfer device (2) includes snow removal devices (5) to remove snow from the aircraft wheel (6) or its path (7).

2. A transfer device (2) in accordance with Patent Claim 1, characteriz ed in that the transfer device (2) includes a brush member (5) located before the drive roller (3) in the direction of the revolution of the wheel (6) of the aircraft (1) to remove snow from the wheel (6) of the aircraft (1) before the point of compression.

3. A transfer device (2) in accordance with Patent Claim 2, characteriz ed in that the brush member includes a revolving brush (5).

4. A transfer device (2) in accordance with Patent Claim 1, characteriz ed in that the transfer device (2) includes a revolving brush (5') adjusted to the path (7) of the wheel (6) of the aircraft (1), which is intended to move snow away from the wheel"s path (7

5. A transfer device (2) in accordance with Patent Claim 1, characteriz ed in that the transfer device (2) includes air blowing and nozzle devices (8), which.are intended to remove snow from the tyre (6) of the aircraft (l),

6. A transfer device (2) in accordance with Patent Claim 1, characteriz ed in that the transfer device (2) includes air blowing and nozzle devices (8), which are intended to remove snow from the path (7) of the wheel (6) of the aircraft (l).