GB2234948A - An aircraft landing gear arrangement - Google Patents
An aircraft landing gear arrangement Download PDFInfo
- Publication number
- GB2234948A GB2234948A GB8918687A GB8918687A GB2234948A GB 2234948 A GB2234948 A GB 2234948A GB 8918687 A GB8918687 A GB 8918687A GB 8918687 A GB8918687 A GB 8918687A GB 2234948 A GB2234948 A GB 2234948A
- Authority
- GB
- United Kingdom
- Prior art keywords
- sidestay
- aircraft
- landing gear
- gear arrangement
- members
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B64—AIRCRAFT; AVIATION; COSMONAUTICS
- B64C—AEROPLANES; HELICOPTERS
- B64C25/00—Alighting gear
- B64C25/02—Undercarriages
- B64C25/08—Undercarriages non-fixed, e.g. jettisonable
- B64C25/10—Undercarriages non-fixed, e.g. jettisonable retractable, foldable, or the like
- B64C25/12—Undercarriages non-fixed, e.g. jettisonable retractable, foldable, or the like sideways
Abstract
An aircraft landing gear arrangement which includes: a main leg 1 which is pivotally mountable to the aircraft; a retraction/extension actuator 6; and a sidestay mechanism 7 which has two side-stay members 8, 9 pivotally connected to one another at 28, whilst the outer end of one of the sidestay members is mounted to the aircraft, and the outer end of the other sidestay members is mounted onto the main leg, wherein one of the mountings of the sidestay members is a pivotal mounting, and the other mounting 27 is a universal joint type connection means, and the axes of rotation of the pivotal mountings are not parallel with respect to one another. The sidestay member which has the pivotal mounting is provided with means 10 to enable rotational movement of the sidestay mechanism which in combination with the connection means enables a substantial section of the sidestay mechanism to rotate about its longitudinal axis with respect to the aircraft. <IMAGE>
Description
AN AIRCRAFT LANDING GEAR ARRANGEMENT
This invention relates to an aircraft landing gear arrangement, and in particular, to an aircraft landing gear arrangement in which certain space and configuration criteria are placed thereon.
Conventional retractable landing gear arrangements comprise:
- an hydraulically activated main leg means; and - a sidestay member; both of which are pivotally mounted onto the aircraft.
In certain aircraft because of the importance to utilise the space available thereon, certain criteria-are laid down on the design of key components in order to utilise the available space at maximum efficiency.
As far as the landing gear is concerned this can mean several things, but most importantly it means, that because of the shape of the space available, the sidestay and main leg pivotal mountings to the aircraft may have to have nonparallel axes of rotation. The existence of nonparallel axes of rotation in the landing gear arrangement, means that as the sidestay member and the main leg means of the arrangement pivot about the mountings onto the aircraft, a high sidewise, turning motion is induced.
Conventionally, this problem, when encountered has been overcome by redesigning the space available in order to enable a landing gear with parallel axes of rotation to be fitted, i.e. the problem has been avoided not solved. The result of avoiding the problem and not solving it has meant that the space available within the aircraft has not been utilised to maximum efficiency.
The present invention is concerned with overcoming this problem, or at least coping with the consequences thereof.
In accordance with the present invention an aircraft landing gear arrangement includes:
- a main leg which is pivotally mountable to
the aircraft;
- a retraction/extension actuator means; and - a sidestay mechanism which has two side
stay members pivotally connected to one
another at one end thereof, whilst the
other end of one of the sidestay members
is mounted to the aircraft, and the other
end of the other sidestay members is
mounted onto the main leg of the landing
gear arrangement wherein one of the
mountings of the sidestay members is a
pivotal mounting, and the other mounting
is a universal joint type connection
means, and the axes of rotation of the
pivotal mountings are not parallel with
respect to one another; wherein the sidestay member having the pivotal mounting is provided with means which enables rotational movement of the sidestay mechanism, and which in combination with the connection means enables a substantial section of the sidestay mechanism to rotate about the longitudinal axis or axes of the sidestay mechanism with respect to the aircraft.
By universal joint type connection means we include all forms of connection means that allow the sidestay member to move freely in response to the folding of the sidestay member about the pivotal connection between the members thereof and any rotational movement induced in the sidestay mechanism by retraction/extension of the landing gear.
Preferably, the two sidestay members are the upper and lower sidestay members, of which the upper sidestay member is provided with the pivotal mounting to the aircraft and the means which enables rotational movement of a substantial section of the sidestay mechanism and the lower sidestay member is provided with the universal joint type connection means to the main leg.
In accordance with a second aspect of the present invention an aircraft landing gear arrangement including:
- a main leg which is pivotally mounted to
the aircraft;
- a retraction/extension actuator means; and - a sidestay mechanism which has upper and
lower sidestay members pivotally connected
to one another at one end thereof, whilst
the upper sidestay member is pivotally
mounted to the aircraft at the other
end and the lower sidestay member is
attached to the main leg at its other end
by a universal joint type connection; wherein the axes of rotation of the pivotal mountings to the aircraft are not parallel with respect to one another, and the upper sidestay member is provided with means which enables rotational movement of the sidestay mechanism and which is in combination with the connection means of the lower sidestay member to the main leg enables a substantial section of the sidestay mechanism to rotate about the longitudinal axis or axes of the sidestay mechanism with respect to the aircraft.
Preferably, the landing gear arrangement further includes an aircraft landing gear arrangement shortening means.
Preferably, the landing gear arrangement has associated therewith a landing gear arrangement lock mechanism.
The extension/retraction actuator means is, preferably, mounted so that it acts between the main leg of the arrangement and one member of the sidestaymember at a position between the pivotal mountings of the sidestay member.
Preferably, the extension/retraction actuator means is a hydraulically operated actuator means.
Preferably, the means which enables rotational movement of the sidestay member comprises a joint which allows torsional freedom in the upper sidestay member, for example, a type of swivel joint.
Preferably, the means which enables rotational movement of the upper sidestay member includes guide means which correctly aligns the sidestay member upon extension or retraction of the landing gear.
In a preferred embodiment of the invention, the means which enables rotational movement of the upper sidestay member is included in the upper sidestay member in the immediate vicinity of the pivotal mounting to the aircraft.
The invention also includes an aircraft including a landing gear arrangement made in accordance with the present invention.
The invention will now be illustrated by way of description of an example as shown in the accompanying drawings, in which:
Figure 1 shows an end view of an aircraft
landing gear arrangement made in
accordance with the present
invention;
Figure 2 shows a side view of the aircraft
landing gear shown in Figure 1 of
the drawings; and Figure 3 shows a plan view of the aircraft
landing gear shown in Figures 1 and
2 of the drawings.
Now referring to the drawings, an aircraft landing gear arrangement 1 made in accordance with the present invention, which comprises:
- a hydraulically operated'main leg member 1
having an upper leg member 2 and a lower
leg member 3;
- a wheel 4 rotatably mounted onto the lower
leg member 3 by a pin 5;
- an aircraft landing gear shortening
mechanism;
- a landing gear extension/retraction
actuator 6; and - a sidestay mechanism 7 having an upper
sidestay component 8 and a lower side stay
component 9 pivotal connected at one end
to each other with the upper component 8
being pivotally attached at its other end
to the aircraft so that it pivots with
respect to the aircraft about an axis AS,
and its lower component 9 being connected
at its other end to the main leg of the
landing gear.
The upper sidestay component 8 is provided with a joint 10 which divides the upper sidestay component 8 into two sections, an upper section 8a and a lower section 8b. The joint 10 is a swivel joint that enables the upper and lower sections of the upper sidestay component 8 to rotate with respect to each other.
The upper section 8a of the upper sidestay component 8 is fixed in space relative to the aircraft by its pivotal mounting to the aircraft, and therefore the joint 10 allows the lower section 8b of the upper sidestay component 8 to rotate relative to the aircraft, in addition to the upper section 8a of the upper sidestay component 8a. The rotational movement of the lower section 8b of the upper sidestay component 8 is transferred to the lower sidestay component 9 by the pivotal connection therebetween.
Further, a guide arrangement is provided in the joint 10 so that the sidestay mechanism 7 is correctly aligned under retraction/extension of the landing gear arrangement 1.
The guide arrangement may comprise anti-roll lobes that engage during the final stages of rotation on extension, or initial stages of rotation on retraction. When engaged the anti-roll lobes prevent axial rotation (rolling) of the sidestay mechanism 7. This is important to ensure the sidestay mechanism 7 does not jam when the sidestay mechanism starts to fold under retraction.
The lower side stay component is connected to the main leg of the given by a joint 7 which has a movement akin to that provided by a universal joint. This provides the lower sidestay component 9 with an ability to allow the lower sidestay member to move in response to motion induced by folding the sidestay mechanism 7 about its pivotal connection of the two sidestay components 8, 9 and any rotational movement induced by extension/ retraction of the landing gear in the siidestay mechanism.
The main--leg via the upper leg member 2 is provided with two mounting means 11 by which it is pivotally mounted to an aircraft (not shown) by means of pins 12. The main leg member 1 of the landing gear arrangement pivots upon extension or retraction of the landing gear with respect to the aircraft about an axis of rotation AM.
The pivot axis AS of the sidestay mechanism 7 with respect to the aircraft and the pivot axis AM of the main leg with respect to the aircraft are nonparallel with respect to each other.
The aircraft landing gear shortening mechanism comprises an actuator member 13 pivotally attached at one end 14 to the aircraft and at the other end 15 to one end of a lever member 16 and one member of a lever arrangement having members 17 and 18, by a common mounting 19;
The actual operation of the shortening mechanism will be understood by those skilled in the art, and therefore no further explanation will be needed or given.
The landing gear arrangement 1 is also provided with two lever members 20, 21 which prevent rotational movement of the upper leg member 2 with respect to the lower leg member 3 whilst allowing longitudinal movement of these members with respect to each other.
One end of one of the lever member 20, the lower lever member, is pivotally connected to the lower end of the lower leg member 3 by pins 22 which engage in mounting means 23 thereon, and one end of the other lever member 21 19, the upper lever member, is pivotally connected by means of pivot pins 24 engaging in mounting means 25 provided at the lower end of the upper leg member 2, to the upper leg member 2.
The other ends of the lever members 20, 21 are pivotally connected to one another by means of a pivot pin 26.
The lever member 16 which is at one end pivotally connected to the actuator member 13 is pivotally attached to the lower end of the upper leg member 2, in the vicinity of the pivotal connection of the upper lever member 21 thereto.
The lever arrangement which has one end of a member 17 thereof, the upper lever arrangement member, pivotally attached to the actuator member 13 has its other end pivotally located to one end of the other member 18 of the lever arrangement, the lower lever arrangement member. The other end of the lower lever arrangement member 18 is attached to one of the pins 22 by which the lower lever member 20 is pivotally attached to the lower leg member 3.
At one end the landing gear extension/retraction actuator 6 is pivotally connected to the upper leg member 2 at a position close to the pivotal connection of the main leg to the aircraft. The other end of the actuator 6 is pivotally connected to the upper section 8a of the upper component 8 of the sidestay mechanism 7 at a position close to the pivotal mounting of the sidestay mechanism 7 to the aircraft, but below the axis of rotation thereof.
The landing gear arrangement 1 is also provided with an uplock landing gear lock mechanism 29.
The lock mechanism is mounted on the aircraft and is engaged by a pin provided on the main leg so as to lock the landing gear in the retracted position.
The landing gear arrangement shown in the drawings is in the extended or landing position. Now in order to retract the landing gear arrangement to the in flight position the actuator 6 is extended forcing the pivot pin 28 of the sidestay mechanism 7 in the direction of the arrow A, causing the wheel 4 to move in the direction of arrow B.
During retraction of the landing gear arrangement due to the non-parallel nature of the pivot axes
AS and AM a sidewise turning motion is induced in the sidestay members 8, 9. In turn this causes the lower section 8b of the upper sidestay component 8 to rotate about the joint 10 and relative to the upper section 8a, as well as the lower sidestay component 9 so preventing the build up of stress in the sidestay mechanism 7, and there failure of the sidestay mechanism 7 as a result of this.
The kinematics of the operation of the landing gear arrangement 1 are such that as the sidestay components 8, 9 pivot about the connection therebetween a sidewise turning motion/force is created, so causing a torque to be induced in the upper sidestay component 8. This torque is not reacted with the present landing gear, and is in fact used to induce rotation of the lower section 8 of the upper sidestay component 8 about the joint 10.
The amount of rotation induced is imperceptible initially however increases/accelerates as the stay folds.
Once in the retracted position the landing gear is locked into position by the uplock landing gear arrangement lock mechanism 29 activates so locking the landing gear arrangement in place.
In order to extend the landing gear into the landing position the lock mechanism 29 is deactivated releasing the landing gear, the actuator 6 retracts moving the pivot pin 28 of the sidestay mechanism 7 in the direction of the arrow
A' causing the wheel to move in the direction of the arrow B'.
As the landing gear arrangement extends a sidewise turning motion in the reverse of that induced during retraction, is induced in the sidestay mechanism 7 causing the sidestay mechanism to rotate. This prevents the build up of stress in the sidestay mechanism 7.
The kinematics of the operation during extension are the reverse of those during retraction.
Claims (12)
1. An aircraft landing gear arrangement includes:
- a main leg which is pivotally mountable to
the aircraft;
- retraction/extension actuator means; and - a sidestay mechanism which has two side
stay members pivotally connected to one
another at one end thereof, whilst the
other end of one of the sidestay members
is mounted to the aircraft, and the other
end of the other sidestay members is
mounted onto the main leg of the landing
gear arrangement wherein one of the
mountings of the sidestay members is a
pivotal mounting, and the other mounting
is a universal joint type connection
means, and the axes of rotation of the
pivotal mountings are not parallel with
respect to one another;; wherein the sidestay member having the pivotal mounting is provided with means which enables rotational movement of the sidestay mechanism, and which in combination with the connection means enables a substantial section of the sidestay mechanism to rotate about the longitudinal axis or axes of the sidestay mechanism with respect to the aircraft.
Amendments to the claims have been filed as follows 1. An aircraft landing gear arrangement includes:
- a main leg which is pivotally mountable to
the aircraft;
- a retraction/extension actuator means; and - a sidestay mechanism which has two side
stay members pivotally connected to one
another at one end thereof, whilst the
other end of one of the sidestay members
is mounted to the aircraft, and the other
end of the other sidestay members is
mounted onto the main leg of the landing
gear arrangement wherein one of the
mountings of the sidestay members is a
pivotal mounting, and the other mounting
is a universal joint type connection
means, and the axes of rotation of the
pivotal mountings are not parallel with
respect to one another;; wherein the sidestay member having the pivotal mounting is provided with means which enables rotational movement of the sidestay mechanism, and which in combination with the connection means enables a substantial section of the sidestay mechanism to rotate about the longitudinal axis or axes of the sidestay mechanism with respect to the aircraft.
2. An aircraft landing gear arrangement as claimed in claim 1, wherein the two sidestay members are the upper and lower sidestay members, of which the upper sidestay member is provided with the pivotal mounting to the aircraft and the means which enables rotational movement of a substantial section of the sidestay mechanism and the lower sidestay member is provided with the universal joint type connection means to the main leg.
3. An aircraft landing gear arrangement including:
- a main leg which is pivotally mounted to
the aircraft;
- a retraction/extension actuator means; and - a sidestay mechanism which has upper and
lower sidestay members pivotally
connected to one another at one end
thereof, whilst the upper sidestay
member is pivotally mounted to the
aircraft at the other end and the lower
sidestay member is attached to the main
leg at its other end by a universal
joint type connection; wherein the axes of rotation of the pivotal mountings to the aircraft are not parallel with respect to one another, and the upper sidestay member is provided with means which enables rotational movement of the sidestay mechanism and which is in combination with the connection means of the lower sidestay member to the main leg enables a substantial section of the sidestay mechanism to rotate about the longitudinal axis or axes of the sidestay mechanism with respect to the aircraft.
4. An aircraft landing gear arrangement, as claimed in any one of the preceding claims in which the landing gear arrangement further includes an aircraft landing gear arrangement shortening means.
5. An aircraft landing gear arrangement as claimed in any one of the preceding claims in which the landing gear arrangement lock mechanism.
6. An aircraft landing gear arrangement as claimed in any one of the preceding claims, in which the extension/retraction actuator means is mounted so that it acts between the main leg of the arrangement and one member of the sidestay member at a position between the pivotal mountings of the sidestay member.
7. An aircraft landing gear arrangement as claimed in any one of the preceding claims, in which the extension/retraction actuator means is a hydraulically operated actuator means.
8. An aircraft landing gear arrangement as claimed in any one of the preceding claims, in which the means which enables rotational movement of the sidestay member comprises a joint which allows torsional freedom in the upper sidestay member, for example, a type of swivel joint.
9. An aircraft landing gear arrangement as claimed in any one of the preceding claims, in which the means which enables rotational movement of the upper sidestay member includes guide means which correctly aligns the sidestay member upon extension or retraction of the landing gear.
10. An aircraft landing gear arrangement as claimed in any one of the preceding claims, in which the means which enables rotational movement of the upper sidestay member in the immediate vicinity of the pivotal mounting to the aircraft.
11. An aircraft landing gear arrangement substantially, as hereinbefore described with reference to the accompanying drawings.
12. An aircraft incorporating a landing gear arrangement as claimed in any one of the preceding claims.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB8918687A GB2234948A (en) | 1989-08-16 | 1989-08-16 | An aircraft landing gear arrangement |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB8918687A GB2234948A (en) | 1989-08-16 | 1989-08-16 | An aircraft landing gear arrangement |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB8918687D0 GB8918687D0 (en) | 1989-09-27 |
| GB2234948A true GB2234948A (en) | 1991-02-20 |
Family
ID=10661708
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB8918687A Withdrawn GB2234948A (en) | 1989-08-16 | 1989-08-16 | An aircraft landing gear arrangement |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2234948A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2010063893A1 (en) * | 2008-12-05 | 2010-06-10 | Messier-Dowty Sa | Device for retracting aircraft landing gear |
| FR3036375A1 (en) * | 2015-11-10 | 2016-11-25 | Airbus Operations Sas | LANDING TRAIN FOR AN AIRCRAFT AND HAVING A LATCHING SYSTEM IN STORAGE POSITION |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB538298A (en) * | 1940-04-30 | 1941-07-28 | Fairey Aviat Co Ltd | Improvements in or relating to retractable undercarriages for aircraft |
| US4047681A (en) * | 1975-12-22 | 1977-09-13 | The Boeing Company | Apparatus for shortening the strut of a pivotally retractable aircraft landing gear during gear retraction |
| GB2132578A (en) * | 1982-12-30 | 1984-07-11 | Messier Hispano Sa | Aircraft landing gear |
-
1989
- 1989-08-16 GB GB8918687A patent/GB2234948A/en not_active Withdrawn
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB538298A (en) * | 1940-04-30 | 1941-07-28 | Fairey Aviat Co Ltd | Improvements in or relating to retractable undercarriages for aircraft |
| US4047681A (en) * | 1975-12-22 | 1977-09-13 | The Boeing Company | Apparatus for shortening the strut of a pivotally retractable aircraft landing gear during gear retraction |
| GB2132578A (en) * | 1982-12-30 | 1984-07-11 | Messier Hispano Sa | Aircraft landing gear |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2010063893A1 (en) * | 2008-12-05 | 2010-06-10 | Messier-Dowty Sa | Device for retracting aircraft landing gear |
| FR2939407A1 (en) * | 2008-12-05 | 2010-06-11 | Messier Dowty Sa | DEVICE FOR SHORTENING AN AIRCRAFT AIRCRAFT |
| US8505849B2 (en) | 2008-12-05 | 2013-08-13 | Messier-Bugatti-Dowty | Device for retracting aircraft landing gear |
| FR3036375A1 (en) * | 2015-11-10 | 2016-11-25 | Airbus Operations Sas | LANDING TRAIN FOR AN AIRCRAFT AND HAVING A LATCHING SYSTEM IN STORAGE POSITION |
Also Published As
| Publication number | Publication date |
|---|---|
| GB8918687D0 (en) | 1989-09-27 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |