GB2193932A

GB2193932A - Tyres for aircraft landing gear

Info

Publication number: GB2193932A
Application number: GB08619845A
Authority: GB
Inventors: Peter John Evans
Original assignee: Individual
Current assignee: Individual
Priority date: 1986-08-14
Filing date: 1986-08-14
Publication date: 1988-02-24
Also published as: GB8619845D0

Abstract

A tyre 1 which is suitable for an aircraft wheel has formations in the form of pockets 2 on both sides thereof. The pockets 2 have open ends 4 which catch air passing the wheel so as to offer resistance to the flow of air and thereby cause the wheel to rotate. The pockets may be replaced by solid protrusions. <IMAGE>

Description

SPECIFICATION Tyres for aircraft landing gear This invention relates to tyres for aircraft landing gear.

Tyres of aircraft landing gear are subjected to considerable wear and tear during landing of the aircraft. Immediately prior to landing, the wheels of the landing gear are not rotating and hence, when the tyres of the wheels make contact with the runway, the wheels are suddenly forced to rotate by virtue of frictional forces between the runway and the tyres.

Due to the considerable speed differential between the runway and the wheels at the point of landing, the tyres tend to slip on the runway surface for a time after the tyres make contact with the runway. This slippage causes considerable wear on the tyres and leads to the tyres having to be replaced relatively regularly. This problem exists in the landing gear of light aircraft as well as large commercial aircrafts.

It is an aim of the present invention to provide a tyre, for aircraft landing gear, which is constructed so that the aforesaid problem is alleviated.

According to the present invention there is provided a tyre for a wheel of an aircraft, wherein the tyre has formations thereon for offering resistance to air passing the tyre as the aircraft lands, which resistance is as such as to cause the wheel to rotate.

Embodiments of the present invention are advantageous in that they can cause the wheel of an aircraft to rotate before contact between the tyre and the runway is made thereby reducing slippage between the tyre and the runway.

In a preferred embodiment of the present invention, the formations are in the form of pockets on one or both sides of the tyre.

Preferably, the pockets are formed of vulcanised rubber and are integral with the tyre.

Alternatively, the formations may be solid, for example, they may be in the form of chevron shaped ribs on one or both sides of the tyre. The ribs are formed so that they are directed in the same direction around the periphery of the tyre thus offering a differential in air resistance between the top and bottom of the wheel so that air passing the wheel forces the wheel to rotate.

The invention will now be further described by way of example, with reference to the accompanying drawings in which like reference numerals designate like elements, in which: Figure 1 shows a side view of a tyre embodying the present invention; Figure 2 shows a plan view of the tyre of figure 1; and Figure 3 shows a side view of a second embodiment of the present invention.

Figure 1 shows a side view of a tyre 1 which is suitable for a wheel of the landing gear of an aircraft (not shown). The tyre 1 has formations in the form of pockets 2 on both sides. The pockets 2 are integrally formed with the tyre 1 and are made of the same material as the tyre 1. This material may be vulcanised rubber.

When the landing gear is down and the aircraft is coming in to land, the whole of the wheel and aircraft is moving in the direction of an arrow A with respect to the ground 3.

Movement of the aircraft gives rise to a considerable flow of air past the tyre in the direction designated by arrows B. As can be seen from figure 1, the pockets 2 have an open end 4 which catches air passing the wheel so as to offer resistance to the flow of air. The pockets 2 taper in the direction shown in figure 1 and all of the pockets 2 on the tyre are directed in the same direction along the periphery of the tyre 1. Consequently, greater resistance is offered by the pockets 2 which are towards the bottom of the tyre 1 since the open ends of the pockets 2 face towards the flow of air. At the top of the wheel the tapered ends of the pockets 2 face towards the direction of the flow of air and so less resistance is offered. The resulting differential in resistance offered to the flow of air past the tyre 1 causes the wheel and the tyre 1 to rotate in the direction of arrow C.

The rotation of the wheel and tyre 1 in direction C, results in less slippage between the tyre 1 and the ground 3 when the tyre makes contact with the ground 3. Consequently, the amount of wear on the tyre is reduced.

Figure 2 shows a plan view of the tyre of figure 1. The distance which the pockets 2 project from the sides of the tyre 1 can be varied in order to increase or decrease the resistance, thus enabling variation of the degree to which the wheel is caused to rotate.

Figure 3 shows a second embodiment of the present invention in which the formations on the tyre 1 are in the form of chevron shaped ribs 5. Again the orientation the ribs 5 is such that greater resistance is offered by the tyre to air passing the tyre 1 in the region closest to the ground 3. The tyre 1 is therefore caused to rotate and in a similar manner to that described with reference to figure 1.

The height and profile of the ribs height may be varied in order to increase or decrease the degree to which the wheel and tyre 1 is caused to rotate in the direction C for a given air speed.

It is to be understood that modifications may be made to either of the embodiments described above without departing from the scope of the present invention, for example, the pockets 4 may be solid. Alternatively, the pockets may be attached to the side of the wheel in a separate manufacturing operation instead of being formed integrally therewith.

Furthermore, the pockets 4 may be of a flexible material which are collapsible when the landing gear is raised into the aircraft but become inflated when the landing gear is down immediately prior to landing.

Claims

1. A tyre for a wheel of an aircraft, wherein the tyre has formations thereon for offering resistance to air passing the tyre of the aircraft and, which resistance is such as to cause the wheel to rotate.

2. A tyre according to claim 1, wherein the formations are in the form of pockets on one or both sides of the tyre.

3. A tyre according to claim 2, wherein the pockets are formed of vulcanised rubber and are integral with the tyre.

4. A tyre according to claim 1 or claim 2, wherein the formations are in the form of solid protrusions.

5. A tyre according to claim 4, wherein the solid protrusions are in the form of chevron shaped ribs on one or both sides of the tyre.

6. A tyre according to claim 5, wherein the chevron shaped ribs are formed so that they are directed in the same direction around the periphery of the tyre thus offering a differential in air resistance between the top and the bottom of the wheel so that air passing the wheel forces the wheel to rotate.

7. A tyre substantially as herein described with reference to Figures 1 and 2 or Figure 3 of-the accompanying drawings.