WO2016142671A1

WO2016142671A1 - Support arrangement for an aircraft seat

Info

Publication number: WO2016142671A1
Application number: PCT/GB2016/050599
Authority: WO
Inventors: Phillip Andrew WATTERSON
Original assignee: Rebel.Aero Limited
Priority date: 2015-03-06
Filing date: 2016-03-07
Publication date: 2016-09-15
Also published as: GB201503829D0

Abstract

The present invention relates to a support arrangement (10) for an aircraft seat (2). The support arrangement (10) relates to a support leg that is arranged to support a seat (2) above the floor (20) of an aircraft. The support arrangement (10) comprises a first part (14) having a first anchoring point arranged to be anchored to the floor (20) of an aircraft and a second part (16) having a second anchoring point arranged to be secured to an aircraft seat (2). The second part (16) is operatively engaged with the first part (14), wherein the first part (14) is deployable downwardly away from the second part (16) from a retracted to an extended configuration to limit variance in the height of an aircraft seat (2) in the event of the first anchoring point being pulled downwardly by the floor (20) of an aircraft, and a retraction impeding arrangement (34) for impeding retraction of the first part (14) from the extended configuration subsequent to deployment.

Description

Support Arrangement for an Aircraft Seat

The present invention relates to a support arrangement for an aircraft seat. In particular the support arrangement relates to a support leg that is arranged to support a seat portion and a backrest above the floor of an aircraft.

A typical aircraft seat design for supporting a passenger comprises a seat part and a backrest part and a frame structure made up of a number of rods secured to each other by mechanical fixings. These rods include a plurality, typically four, support legs which are arranged to be secured to tracks provided in the aircraft floor. These tracks typically extend along the longitudinal length of the aircraft and the seat legs are secured relative to these tracks via standard fittings.

Aircraft seats have been made in this way for many years as such a framework for the backrest and seat portion provides a seat of reasonable strength and also comprises a large number of joints secured by mechanical fixings which under crash or crash simulation testing can accommodate different stresses incurred when the anchoring points for the seat legs are deformed. For example, in a crash or crash test simulation a forwardly extending leg may pitch forward suddenly whilst the remainder of the legs may remain substantially in the same position. This simulates the floor of the aircraft suddenly deforming downwardly. In such a situation the mechanical fixings associated with the frame structure can inherently accommodate a certain degree of this pitching. Furthermore, one or more legs may be rolled laterally putting further stresses on the seat. Again, known seats utilising a frame structure made up of the plurality of rods secured by mechanical fixing means can accommodate such stresses to a certain degree without fracturing.

A problem, however, exists with aircraft seats in that they are extremely complex to manufacture due to the significant number of parts, they are expensive to manufacture due to the assembly time and the number of individual components and are further relatively heavy due to the materials utilised and again the number of components utilised. It is desirable, therefore, to manufacture a seat of non-traditional design such as through moulding or other forming techniques. Such seats provide significant benefits in terms of reduced weight, forming time and cost however are not utilised for aircraft seats due to the lack of capability of accommodating the stresses associated with crashes or crash simulation. This is a result of increasing stiffness. The present invention therefore provides a support arrangement for supporting an aircraft seat that overcomes such problems. The invention also extends to an improved aircraft seat.

According to the present invention there is a support arrangement for supporting an aircraft seat comprising a first part having a first anchoring point arranged to be anchored to the floor of an aircraft and a second part having a second anchoring point arranged to be secured to an aircraft seat, the second part being operatively engaged with the first part, wherein the first part is deployable downwardly away from the second part from a retracted to an extended configuration to limit variance in the height of an aircraft seat in the event of the first anchoring point being pulled downwardly by the floor of an aircraft, and a retraction impeding arrangement for impeding retraction of the first part from the extended configuration subsequent to deployment.

The support arrangement of the present invention is therefore capable of accommodating movement of an anchoring point on an aircraft floor away from the seat. This may occur during a crash or crash simulation wherein the aircraft floor deforms non-linearly. As such one of the anchoring points may pitch downwardly relative to the other seat anchoring points resulting in a significant force being put onto the support arrangement. The support arrangement may be termed a leg or support leg. The first part in use is anchored to the floor of an aircraft in a fixed position.

The present invention is particularly beneficial for supporting aircraft seats of non- traditional frame construction. Traditional aircraft seats comprise numerous rods secured together by mechanical fixing means to form a frame. Secured to the frame are support legs and a backrest, which may be pivotally mounted relative to the frame. As such each mechanical fixing means can accommodate pitching or twisting of an anchoring point relative to one or more other anchoring point such that the seat squab onto which a passenger seats remains in position. However, for alternative seat constructions, through moulded and/or bonded frames, there are fewer mechanical fixing means resulting in such stresses not being accommodated and catastrophic fracture is likely. The support arrangement is preferably a support leg. A plurality of support legs beneficially support an aircraft seat, where for example four support legs support an aircraft seat which may have one, two or three adjoined passenger seating positions. It will be appreciated however that it is not essential to provide four support arrangements according to the invention for supporting an individual aircraft seat arrangement. The seat supports a user in a seated position.

The support structure comprises a retraction impeding arrangement for impeding retraction of the first part from the extended configuration. Thus movement from the extended back to a retracted configuration is resisted following deployment. This is important as in a crash or crash simulation situation sudden pitching of the aircraft floor comprising one or more anchoring point relative to one or more other anchoring points may then be followed by sudden deceleration of the aircraft and thus the seat. In this event the seat and second part of the support arrangement secured to the seat would be forced back towards the retracted configuration. This would have the effect of effectively throwing a passenger forwardly with massive force, potentially causing serious damage to the passenger through throwing the passenger into the seat in front. A further effect would be the potential of catastrophic failure through fracture of the seat due to the seat only being supported by a reduced number of legs. Thus the load on the seat would be increased upon each remaining support leg. The applicant has therefore realized that the provision of such a retraction impeding arrangement provides a significant feature in reducing the possibility of fracture failure of the seat, in improved passenger safety in a crash, and capability of complying with crash simulation tests.

It is beneficial that retraction from the extended configuration is prevented. This removes the possibility of accidental retraction during a crash/crash simulation. Therefore, it is beneficial that once deployed, retraction is not possible unless the strength of the retraction impeding arrangement is overcome. This however may be calculated and the retraction impeding arrangement configured to prevent retraction under normal and under crash conditions. The first and second parts are therefore preferably locked in the

extended/deployed configuration. The retraction impeding arrangement preferably deploys upon removal of tension applied between the first and second parts.

The support arrangement has a longitudinal length, and extension from the retracted to the extended, deployed configuration is beneficially enabled longitudinally. The support arrangement is in use positioned intermediate the seat for supporting a user and the aircraft floor.

The first part is preferably moveable away from the second part over an extension range between the retracted and a maximum extension configuration, and wherein the retraction impeding arrangement is arranged to impede retraction from an extended configuration in the extension range intermediate the retracted and maximum extension configuration.

Therefore, it will be appreciated that retraction will be impeded from an extended configuration intermediate the retracted configuration and maximum extended

configuration.

This is important as in a crash or crash simulation the floor of the aircraft may not deform to an amount that causes the first part to extend to the maximum extension configuration, rather an intermediate position. However, it is still important that retraction is impeded from this intermediate extension configuration. Beneficially, retraction is impeded from any intermediate extended configuration in addition to a maximum extension

configuration.

The retraction impeding arrangement provides an important function in the present invention by preventing sudden retraction of the second part from the deployed

configuration which could cause significant harm to a passenger in a crash situation.

Accordingly, it is beneficial that the retraction impeding arrangement is activated or is reconfigurable without user intervention. As such, in a first configuration the first part is extendible relative to the second part, and in a second configuration retraction of the first part relative to the second part is impeded. It is beneficial that there is unimpeded movement of the first part to the second or extended configuration.

The retraction impeding arrangement preferably comprises a locking element retained between the first and second parts, the locking element moveable between a first position whereby extension of the first part relative to the second part is enabled, and a second position whereby the locking element engages the first part and resists retraction between the first part and the second part. It will be appreciated that no user intervention is required to enable the first part to extend relative to the second part, in particular with respect to the impeding arrangement.

Deployment of the first part preferably causes movement of the locking element from the second position to the first position.

The locking element beneficially comprises one or more lock rings seated between the first and second parts. In a preferred embodiment the one or more lock rings are positioned externally of the first part, and internally of the second part. It has been determined that a plurality of spaced apart lock rings are beneficially utilised, depending upon the resistance to retraction required.

The retraction impeding arrangement beneficially further comprises a biasing means, preferably a spring, arranged to bias the locking element to the second position, wherein deployment of the first part causes the locking element to deform the biasing means to the first configuration. It will be appreciated that following deployment, the biasing means returns the locking element to the second configuration.

The locking element is beneficially a locking ring, and in the second configuration the locking ring is tilted relative to the longitudinal axis of the first and second part.

Deployment of the second part causes tilting of the locking ring to closer alignment with the axis perpendicular to the longitudinal length of the support arrangement. In an alternative definition, the locking ring rotates between the second and first configuration.

The first and second parts beneficially slidably engage, and preferably telescopically engage. In the exemplary embodiment presented the first part is received by the second part, however it will be appreciated that this configuration could be reversed and the second part could be received by the first part.

A further problem encountered under aircraft crash or crash simulation event is that in addition to the aircraft floor effectively giving way meaning that the seat attempts to pitch forwards, there is also likelihood of the requirement for accommodation of some lateral and preferably pivotal movement of the first anchoring point. The first anchoring point may move laterally meaning that between first and second anchoring points the effective separation between these points either increases or decreases. Furthermore, as the first anchoring point pitches forwardly, some pivoting of the anchoring point may also occur.

Traditionally constructed aircraft seats can withstand some lateral or pivotal deflection of the anchoring point through the support frame construction of multiple rods and mechanical fixings, however the present invention has been designed to improve such properties, particularly but not exclusively for aircraft seats manufactured to different specifications particularly having stiffer construction. The support arrangement has been designed to accommodate such eventualities.

Accordingly, the first and/or second part beneficially comprises a mounting structure, the or each mounting structure for mounting the first anchoring point to the floor of an aircraft and mounting the second anchoring point to a seat, the or each mounting structure configured to enable pivotal and/or lateral movement of a seat relative to the aircraft floor.

In a preferred embodiment the mounting structure is utilised to mount the first mounting point to the aircraft floor. It will be appreciated that the second mounting point as described elsewhere in the specification can be fixedly secured to seat, and may be integrally formed with or bonded to the seat. Preferably, the or each mounting structure comprises a first mounting portion and a second mounting portion wherein the first mounting portion cups the second mounting portion to enable lateral and/or pivotal movement therebetween. The first and second mounting portions may comprise a ball and socket respectively.

The first mounting portion may comprise a slot, the slot being generally U shaped and having a narrowed neck for retaining the second structure in the slot. Such configuration enables positive securing of the first and second mounting portions, whilst also allowing lateral or side to side movement, and also further allowing pivotal movement. It will be appreciated that the opening to the slot extends perpendicular to the longitudinal length of the support arrangement. The slot preferably comprises a first curved abutment surface and the second mounting portion has a second curved abutment surface such that the first and second curved abutment surfaces engage one another.

The first mounting portion is preferably arranged to be secured to the floor of an aircraft. The first mounting portion preferably comprises formations to enable mechanical fixing means such as bolts to secure the first mounting portion to standard tracks formed in an aircraft floor.

The neck of the slot preferably provides opposing shoulders for preventing release of the second mounting portion. The slot is preferably open generally upwardly in use.

There is beneficially provided a fixing element arranged to retain the first and second parts in the retracted configuration, and being arranged to release in the event of sufficient tension being applied between the first and second parts. The fixing element beneficially releases upon a predetermined tension being applied between the first and second part. This is an important feature of the present invention as it prevents accidental deployment of the second part. This could potentially be caused by a passenger putting downward force on a backrest of a seat, or sitting on a pull-out seat tray for example. The fixing element ensures that accidental deployment will not occur. It is further beneficial that the fixing element breaks in the event of sufficient stress (tension) being applied between the first and second part. The fixing element may comprise a shear pin.

The present invention also extends to an aircraft seat comprising a seating platform, and one or more support structures as hereinbefore described. The aircraft seat preferably further includes a backrest. It will be appreciated that aircraft seats can provide one or more zones for accommodating passengers, and may include one, two, three or even four individual passenger seating zones. Accordingly, more than one support arrangements according to the present invention may be utilised.

It is further beneficial that the aircraft seat comprises a seating platform and backrest at least partially integrally formed. This means that they are not secured together using mechanical fixings, but instead are for example formed together using a composite structure such as carbon fibre. This increases stiffness of the aircraft seat, which can be compensated for through the provision of the support structure. Furthermore, the shape of the aircraft seat as a whole can be improved to accommodate improved passenger comfort and speed of embarking and disembarking the aircraft.

It is preferred that the second part of the support structure is further beneficially bonded to the seating platform. This again further increases stiffness of the aircraft seat, but reduces weight.

The present invention will now be described by example only with reference to the accompanying drawings in which:

Figure 1 is a schematic perspective view of an aircraft seat including support assemblies according to an exemplary embodiment of the present invention.

Figure 2 is a schematic perspective view of a support arrangement according to an exemplary embodiment of the present invention in the retracted configuration focusi the first and second parts 14, 16 and the external appearance thereof. Figure 3 is a schematic perspective view with a shroud of the support arrangement removed, where the shroud when assembled shrouds the second part 16. Figure 3 therefore shows visible components when the shroud is removed in the retracted configuration. Figure 4 is a schematic perspective view of the arrangement of Figures 2 and 3 with further componentry removed in order to better understand the support arrangement of the present invention.

Figure 5 is a schematic perspective view of the support arrangement in an extended or deployed configuration whereby the first part 14 has moved away from the second part 16. It will be appreciated that this is schematic in nature only and for clarity purposes has been shown without the floor of the aircraft having undergone deformation.

Figure 6 is a cross sectional view of the support arrangement according to an exemplary embodiment of the present invention as presented in Figure 3.

Figure 7 is a schematic cross sectional view of the support arrangement according to an exemplary embodiment of the present invention in the extended or deployed configuration as presented in Figure 5.

Figure 8 is a schematic cross sectional view of the first and second part as the first part is moving away from the second part as it is extending or deploying. This shows in detail the functionality of the retraction impeding arrangement. Figure 9 is a schematic cross sectional view of the support arrangement in an extended or deployed configuration whereby a compression or retraction force is being applied in attempting to retract the first part 14 into the second part 16.

Figure 10 is a schematic cross-sectional view of an exemplary embodiment of the present invention. Figure 11 is a schematic representation of an exemplary embodiment of the present invention with various components removed in order to clearly identify an exemplary retraction impeding arrangement. Referring to Figure 1 there is a schematic perspective view of a seat according to an exemplary embodiment of the present invention also including a plurality of support arrangements also according to the exemplary embodiments of the present invention. The seat 2 comprises a backrest 4 and seating platform 6 onto which is supported a seat cushion 8. In the exemplary embodiment shown the seat is folding in nature comprising a forward seat portion and a rearward seat portion 8a, 8b, wherein the forward seat portion is reconfigurable between a side-by- side configuration with the rearward seat portion and a displaced configuration where the forward seat portion pivots to seat on top of the rearward seat portion 8b. The aircraft seat 2 further comprises a plurality of support arrangements 10 which in the embodiment shown are forwardly extending support legs. Due to crash simulation techniques and likely crash situations, it is beneficial to utilise the support arrangements as forwardly facing legs. As shown in Figure 1 the aircraft seat further comprises additional legs 12 for securing to tracks formed in the aircraft floor. The support arrangement is also arranged to secure to the tracks provided in the aircraft floor which are of a fixed separation. A cross support 13 extends between support arrangements 10 and is secured relative to the leg 12. The aircraft seat as presented in Figure 1 comprises three seating areas to accommodate three passengers. Such seats are typically for economy class travel.

Referring to Figure 2 the lower portion of a support arrangement 10 is presented according to an exemplary embodiment of the present invention. It will be appreciated that this is an external view only and thus does not show the features that enable deployment. Presented are the first part 14 and second part 16 of the support assembly 2. In the embodiment presented the first part comprises an extension portion 36 shown clearly in Figure 3 which is telescopically received into the second part 16. However, it will be appreciated to the skilled addressee that the opposite configuration could be utilised whereby the second part is received into the first part 10. The first and second parts 10, 12 beneficially slideably engage and beneficially telescopically engage. Accordingly, in the event that the track 18 -l ion the aircraft floor 20 suddenly pitches forwards then such movement can be

accommodated by the support assembly 2, through the first part 14 being moveable away from the second part 16. Referring to Figure 3 the shrouding of the second part 16 has been removed to clearly show the extension portion of the first part 14 locating into a cartridge 3 which is bonded to the seat itself. Removing the shroud clearly shows how the extension portion 36 is telescopically engageable with the cartridge 3. Referring to Figure 4, in order to further aid understanding of the present invention the majority of the cartridge 3 has been removed to show the extension portion 36 including one or more bushings or shims for 21 which are provided to reduce friction associated with extension of the first part 14 relative to the cartridge 3. Again it is reiterated that extension will occur downwardly due to deformation of the floor onto which the first part 14 is secured. A plate 29 is provided which is secure to the cartridge 3 and retains lock ring 34 and spring plate 28 in position.

The shoulder 30 projecting rearwardly from the cartridge 3 of second part 16 which is effectively arranged to aid in deployment of the first part 14 relative to the second part 16 in the event of pitching forwards of the first part 14 due to a crash or crash simulation. The shoulder 30 abuts a contact surface 31 of the first body portion 14 and due to the rotation forwardly of the first body portion 14 this aids in deployment of the first part 14 away from the second part 16 in order to telescopically extend. Preventing unintentional deployment is fixing element 32 which is sacrificial and in the event of sufficient force between the first and second parts 14, 16 (and in particular sufficient tension between these two parts) the fixing element 32 breaks and the second part and first part telescopically deploy. The provision of the shoulder 30 aids this breakage of the fixing element 32.

It will be appreciated that in normal use deployment does not occur for example through a passenger hanging from the rearward upper edge of the backrest 4. This force is not sufficient to overcome the strength of the fixing element 32. However, during a crash or crash simulation when the first part 14 is violently pitched forwardly and downwardly at the same time the significant force on the fixing element 32 causes fracture and thus deployment.

The deployed configuration is a configuration whereby relative extension of the first and second parts 14, 16 has occurred. This relative extension may be any increase in longitudinal length between the retracted and a maximum extension configuration.

Referring to Figure 5 the first part 14 is secured to the aircraft floor. Shown in Figure 5 is contact surface 31 against which shoulder 30 abuts. The first part 14 comprises a mounting structure configured to enable pivotal and preferably lateral movement of a seat relative to the aircraft floor. The mounting structure of the first part 14 comprises a first mounting portion 22 adapted to enable securing to the aircraft floor and second mounting portion 24 wherein the first and second mounting portions engage to enable lateral and preferably pivotal movement. This is important as it will be understood that it is possible in a crash or crash simulation that the spacing between respective support structures may increase and as such some lateral movement is accommodated. Furthermore, as pitching of the floor occurs there will be some inherent relative rotation between the first mounting portion 22 and the second mounting portion 24 which is accommodated through the presented design. In the presented design the first mounting portion 22 cups the second mounting portion. The first mounting portion can be seen to effectively provide a slot 26 best presented in Figure 5 into which the second mounting portion 24 is received. The neck of the slot provides opposing shoulders 28 for preventing release in the longitudinal length of the support arrangement 2. Through this design it will therefore be appreciated that lateral movement is enabled in the transverse axis and that some rotation is enabled through the provision of curved abutment or complementary bearing surfaces. It should be noted that Figure 5 is schematic and it is the first part 14 that pitches downwardly rather than the second part 16 extending upwardly.

Once in the deployed configuration as presented in Figure 5 it is extremely important that there is no retraction relatively between the first and second parts 14, 16. This is extremely important as it is possible that in a crash or crash simulation situation the aircraft may decelerate at an extremely high rate meaning that if the first and second parts 14, 16 could retract a passenger located in the seat may be thrown suddenly forwardly. Additionally, the seat could only be supported on a reduced number of legs meaning that again catastrophic fracture could occur. In order to reduce this possibility there is provided a locking element 34 clearly shown in Figure 4 in the form of a lock ring retained between the extension portion 36 of the first part 14 and the inner surface of the second part 16. This lock ring 34 is extremely important as it prevents sudden retraction from the deployed configuration. The lock ring is retained in a tilted configuration in the non-deployed state through the provision of a biasing means comprising a spring plate 38. Without this lock ring, assuming the fixing element was broken, extension and retraction would be unimpeded. In the non-deployed configuration therefore the spring plate 38 biases the forward edge of the lock ring 33 upwardly and into contact with the external surface of the extension portion 36 of the first part 14. The rearward portion of the lock ring 34 also sits in communication with the extension portion 36. Figures 6 and 7 are schematic cross sectional views of the support arrangement as presented in Figures 3 and 5 respectively in the retracted and extended configurations.

Figure 7 clearly shows the function of the fixing element 32. As the first part 14 has moved away from the second part 16 the tension between the two parts in the longitudinal length is sufficient to break the fixing element 32 which is effectively a shear pin.

Referring to Figure 8 upon deployment the first part 14 moves away from second part 16 and at this moment there is relative movement between part 16 and part 14 and as the lock ring 34 is retained by the second part 16 the forward portion is forced downwardly towards the first part 14 due to the direction of movement against the spring plate 38. The lock ring 34 therefore rubs against the extension portion 36 of the first part 14. This is shown in Figure 8 where the lock ring 34 is generally perpendicular to the extension portion 36. Referring to the magnified view in Figure 8, the lock ring 34 offers no or minimal restriction to movement and is free to flatten the spring plate 38 against the plane 35. The lock ring 34 is housed in a chamber 39 defined between the extension portion 36 and the magazine 3 which is shaped to allow tilting of the lock ring 34 between the release and locked configuration. Importantly, after deployment and upon release of tension pulling apart the first and second parts 14, 16 the tilted angle of the lock ring 34 causes the rearward edge to communicate with the extension portion 36 and prevent relative retraction. Upon applying compression between the first and second parts 14, 16 and subsequently increasing the compressive force, the lock ring 34 engages and then bites into the first part thus preventing retraction. The support arrangement therefore can effectively only deploy and cannot subsequently retract. This is presented in Figure 9 where the lock ring 34 is effectively pulled into plane 41 which in turn twists the lock ring 34 hard against the extension portion 36 resulting in a locking action thereby preventing relative contraction. Importantly this will occur at whatever position the first and second parts have extended to longitudinally meaning that maximum extension is not required for the lock ring 34 to activate and prevent retraction.

Referring to figures 10 and 11 a slight modification of the support arrangement 10 is presented. In this embodiment a plurality of lock rings 34 are provided spaced apart longitudinally, each arranged to move between a first position whereby extension of the first part 14 relative to the second part 16 is enabled and a second position whereby the locking elements 34 engage the first part 14 and resist retraction between the first part 14 and second part 16. It will be appreciated that in figures 11 and 12 the lock rings 34 are shown in the second position. Each lock ring 34 is biased towards the second position by an associated spring plate 38. The provision of a plurality of lock rings 34 increases resistance to retraction between the first and second parts 14, 16.

Further referring to figures 10 and 11 an alternative mounting structure is presented for securing the first part 14 to the floor of an aircraft. In this embodiment the first part 14 comprises a mounting structure in the form of a ball joint 50 which seats into an opening formed in the cross support 13 as best presented in figure 1. The mounting structure of the first part 14 therefore comprises a first mounting portion 22 and the second mounting portion is in the form of the ball joint 50. The ball joint 50 is retained in the cross support 13 by a clamping structure 52. The clamping structure 52 is enabled to move

longitudinally relative to the longitudinal axis of the cross support 13. The clamping structure itself beneficially moves longitudinally. The mounting structure 52 may for example include an insert for receiving the ball joint 50. The insert may comprise a polymeric material such as PTFE. Such a configuration enables some relative lateral movement of the first part 14 relative to the mounting portion 22 in the event of deployment of the first part 14 relative to the second part 16.

The present invention has been described by way of example only and it will be appreciated to the skilled addressee that modifications and variations may be made without departing from the scope of protection afforded by the appended claims.

Claims

A support arrangement for supporting an aircraft seat comprising a first part having a first anchoring point arranged to be anchored to the floor of an aircraft and a second part having a second anchoring point arranged to be secured to an aircraft seat, the second part being operatively engaged with the first part, wherein the first part is deployable downwardly away from the second part from a retracted to an extended configuration to limit variance in the height of an aircraft seat in the event of the first anchoring point being pulled downwardly by the floor of an aircraft, and a retraction impeding arrangement for impeding retraction of the first part from the extended configuration subsequent to deployment.

2. A support arrangement according to claim 1 wherein the support arrangement is a support leg.

3. A support arrangement to any preceding claim wherein the first part deploys away from the second part over an extension range between the retracted and a maximum extended configuration and wherein the retraction impeding arrangement is arranged to impede retraction from a plurality of extended configurations in the extension range.

4. A support arrangement according to any preceding claim wherein the retraction impeding arrangement is activated without user intervention.

5. A support arrangement according to any preceding claim wherein the retraction impeding arrangement deploys upon removal of tension applied between the first and second parts.

6. A support arrangement according to any preceding claim wherein the retraction impeding arrangement comprises a locking element retained between the first and second parts, the locking element moveable between a first position whereby extension of the first part relative to the second part is enabled, and a second -Imposition whereby the locking element engages the first part and resist retraction between the first part and the second part.

A support arrangement according to claim 6 wherein deployment of the first part causes movement of the locking element from the second position to the first position.

A support arrangement according to claim 7 wherein the retraction impeding arrangement further comprises a biasing means, preferably a spring, arranged to bias the locking element to the second position, wherein extension of the second part relative to the first part causes the locking element to deform the biasing means to the first configuration.

A support arrangement according to any of claims 6-8 wherein the locking element comprises one or more lock rings seated between the first and second parts.

A support arrangement according to any of claims 6-9 wherein the locking element is a locking ring, and in the second configuration the locking ring is tilted relative to the longitudinal axis of the first and second part.

A support arrangement according to any preceding claim wherein the first and/or second part comprise a mounting structure, the or each mounting structure for mounting the first anchoring point to the floor of an aircraft and mounting the second anchoring point to a seat, the or each mounting structure configured to enable pivotal and/or lateral movement of a seat relative to the aircraft floor.

A support arrangement according to claim 11 wherein the or each mounting structure comprises a first mounting portion and a second mounting portion wherein the first mounting portion cups the second mounting portion to enable lateral and/or pivotal movement therebetween. A support arrangement according to any of claims 11-12 wherein the first mounting portion comprises a slot, the slot being generally U shaped and having a narrowed neck for retaining the second structure in the slot.

A support arrangement according to claim 13 wherein the slot comprises a first curved abutment surface and the second mounting portion has a second curved abutment surface such that the first and second curved abutment surfaces engage one another.

A support arrangement according to any of claims 11-14 wherein the first mounting portion is arranged to be secured to the floor of an aircraft.

A support arrangement according to any preceding claim comprising a fixing element arranged to retain the first and second parts in the retracted configuration, and being arranged to release in the event of sufficient tension being applied between the first and second parts.

A support arrangement according to any preceding claim wherein the first part and second part slidably engage, and preferably telescopically engage.

An aircraft seat comprising a seating platform and a support structure according to any preceding claim, wherein the second part is secured to the seating platform.

A support arrangement as hereinbefore described with reference to the

accompanying drawings.