GB2294018A

GB2294018A - Wing twist control and adjustment system

Info

Publication number: GB2294018A
Application number: GB9505237A
Authority: GB
Inventors: William Dominic Pain
Original assignee: Individual
Current assignee: Individual
Priority date: 1994-10-11
Filing date: 1995-03-15
Publication date: 1996-04-17
Also published as: GB9505237D0

Abstract

A method of controlling wing twist on hangliders or microlight aircraft, that rise weight shift control and a means to enable a pilot to vary the amount of twist in the wing during flight by means of an attachment 6 to a wing rib 1 and a tensioning line 5, that pivots round a pulley or similar device 4, that is attached to a spar 3. A leading edge definer 2 holds the front of the aerofoil in place. Alternative arrangements are shown in figures 4, 6 and 7. Augmentation of weight shift imputs can be achieved by cross linking the tensioning line to a rib on the opposite wing thereby allowing the twist in the wing to transfer - one wing twisting up and the other wing twisting down. By shortening tensioning line 5 the overall wing twist is reduced. <IMAGE>

Description

WING TWIST CONTROL AND ADJUSTMENT SYSTEM This invention relates to flexwing hangliders and microlight aircraft.

Flexwing hangliders and microlights are well known examples of weight shift control flying machines. Problems of controlling the amount of wing twist while maintaining good control characteristics has been a compromise problem resulting in relatively inefficient wings due to excessive wing twist. The main way used to control wing twist has been to use spanwise tension.

According to the present invention there is provided a means of controlling the wing twist and making it adjustable via an attachment to a wing rib aft of a leading edge to a wing and applying a controllable amount of tension to this point and a means is provided to cross link the tension to a rib on the opposite wing thereby controlling the angle of the rib so tensioned and augmenting weight shift imputs by allowing one rib to go up and the other rib to go down in effect wing warping.

Four specific embodiments of the invention will now be described by way of examples with reference to the accompanying drawings in which figures 1, 2 & 3 relate to the first example, figures 4 & 5 relate to the second example and figures 6 & 7 relate to the third and fourth examples respectively.

The first specific embodiment of the invention will now be described by way of an example with reference to the accompanying drawings in which: Figure 1 shows a cross section of the example rib and attachment; Figure 2 shows how the attachment and tensioning line can be attached to the wing spar and cross linked to an opposite rib.

Figure 3 shows in perspective an example set up of the wing twist control and adjustment system.

Referring to the drawing the wing twist control and adjustment system comprises a leading edge definer 2 that locates the front of the aerofoil and a rib 1 and an attachment 6 to a tensioning line 5 that pivots round a pully or similar devise 4 that is located on a spar 3. By means of varying the length of the tensioning line the angle of the rib can be set. In order to augment weight shift imputs the tensioning line 5 can be attached to another rib on the opposite wing in the same way thereby allowing the wing to warp - one wing's twist increased and the other wing's twist decreased.

In order to decrease the overall twist of a wing the tensioning line simply needs to be shortened or in effect shortened like pulling back on a bow string by any means. Any number of ribs with attachments can be used depending on the degree of control needed to obtain the desired wing twist distribution.

A second specific embodiment of the invention will now be described by way of another example with reference to the accompanying drawings in which: Figure 4 shows in perspective looking down on the left wing the wing twist control and adjustment system as applied to a leading edge spar and cross boom construction.

Figure 5 shows in perspective viewed from the side the wing twist control and adjustment system as applied in Figure 4.

Referring to figures 4 & 5 the wing twist control and adjustment comprises a leading edge spar 7 that locates the front of the aerofoil and a spanwise rib 9 and an attachment 6 to a tensioning line 5 that pivots round a pully or similar devise 4 that is located to a crosstube spar 8. Any number of cordwise ribs 1 can be attached to the spanwise rib 9 via attachments 10 or any similar means. With the front of the aerofoil located by the leading edge spar varying the length or tension of the tensioning wire will change the angle of the rib.

Cross linking the tensioning line to an opposite wing and adjusting the overall twist in the wing is achievable in the same way as described in the previous example embodiment of the invention.

A third specific embodiment of the invention will now be described by way of another example with reference to the accompanying drawings in which: Figure 6 shows a plan view of the wing twist control and adjustment system incorporating a lever that activates the twist control by pivoting around a cross boom and a leading edge spar.

Referring to figure 6 the wing twist control and adjustment system comprises a leading edge spar 7 that locates the front of the aerofoil and a lever 12 connected to a spanwise rib 9 via attachment 13 and connected to leading edge spar 7 via an attachment 11 with a tensioning line 5 attached to lever 12 at 6 pivoting round a pully or similar device 4 located on cross boom 8. Any number of ribs 1 can be attached to spanwise rib 9 via attachments 10. Any number of levers 12 can be utilized and positioned where desired along cross boom 8 and leading edge spar 7 to optimize mechanical advantages. Spanwise rib 9 can be dispensed with ny directly connecting ribs 1 to lever 12.With the front of the aerofoil located by the leading edge spar varying the length or tension of the tensioning wire will change the angle of the rib by allowing the rear of the lever to rise or pulling the rear of the lever down.

Cross linking the tensioning line to an opposite wing and adjusting the overall twist in the wing is achievable in the same way as described in the previous example embodiments of the invention.

A fourth specific embodiment of the invention will now be described by way of another example with reference to the accompanying drawing in which: Figure 7 shows in perspective the wing twist control and adjustment system as applied to a "D" box construction.

Referring to the drawing the wing twist control and adjustment system comprises a "D" box spar 14 which locates the front of the aerofoil and serves to give a pivot point 4 for a tensioning wire 5 that attaches to rib 1 via attachment 6.

Varying the length or tension of the tensioning wire will effect a change in the angle that rib 1 is held at. Any number of ribs can be utilised to achieve the desired control.

Any combination of the described four example embodiments can be used.

Claims

1 A wing twist control and adjustment system by means of an attachment to a wing rib aft of a leading edge of a wing and applying a controllable amount of tension to this point thereby controlling the angle of a rib so tensioned.

2 A wing twist control and adjustment system as claimed in Claim 1 wherein is provided a means to crosslink the controlling tension on a rib on one wing to a rib on another wing thereby augmenting weight shift imputs by allowing one wing to twist more and the other wing to twist less.

3 A wing twist control and adjustment system as claimed in Claim 1 or Claim 2 wherein the tension controlling the angle of a rib or ribs is made controllable to a pilot in flight thereby enabling the pilot to vary the amount of twist in the wing whilst in flight.

4. A wing twist control and adjustment system substantially as described herein with reference to Figures 1, 2, 3, 4, 5, 6 and 7 of the accompanying drawings.