GB2476385A

GB2476385A - A seat belt arrangement for seats which can recline

Info

Publication number: GB2476385A
Application number: GB1021396A
Authority: GB
Inventors: James Thompson
Original assignee: J Thompson Solutions Ltd
Current assignee: J Thompson Solutions Ltd
Priority date: 2009-12-17
Filing date: 2010-12-16
Publication date: 2011-06-22
Anticipated expiration: 2030-12-16
Also published as: GB0922069D0; GB201021396D0; GB2476385B

Abstract

A seat belt arrangement for a seat which is slidable/ reclinable with respect to a base 45 and having a restraining belt 24 comprises at least one belt anchor 25 coupled to said seat and operable between a non-locking state and a locking state, wherein complementary interlocking formations (e.g., hook 25C and pin 28) are provided on the belt anchor and the seat base, wherein in the inter-locked state the formations are latched to prevent movement of said seat with respect to said base, wherein the belt anchor moves from said non-locking to locking state in response to a force / momentum exerted on said belt anchor by said restraining belt. Friction or a shear pin may hold the seatbelt anchor and base in an unengaged state. This seat belt arrangement is envisaged on fully reclining / sleeping seats in first / business class in aircraft. The seat will have to be moved to the taxi-takeoff-landing (TTL) position for the arrangement to work.

Description

LOAD HANDIJNG APPARATUS FOR PASSENGER RESTRJMNT BELTS

FIELD OF THE INVENTION

The present invention relate to passenger seating, especially aircraft seating.

More particularly the invention relates to handling loads from passenger restraint belts.

BACKGROUND TO THE INVENTION

New aircraft seating systems have recently been developed that provide more comfort and space by reclining to horizontal beds and occupy less aircraft floor space. These require greater and more complex recline movements than are possible with the traditional simple rotating backrest methods. For instance, reclining an occupant from the upright position to a horizontal bed position by moving the seat surfaces forward so that, when in the bed mode, the top of the bed is no further aft than the seat was when fully upright, can be more efficient with the aircraft floor area.

Normally seats used for aircraft have a recline facility and this is usually achieved by pivoting the backrest about a fixed axis close to where the backrest interfaces with the seat base and close to the lap belt anchor points. Tn this case the occupant can be restrained in all positions simply because the lap belt anchor has a fixed position with reference to the seat supporting carriage and structure, and the attachment to the aircraft load bearing structure such as the floor rails.

Passenger restraints are required during all phases of aircraft flight. Under normal circumstances it is recommended that passengers have their restraints loosely fastened to protect them in the event of unexpected turbulence or manoeuvres.

During taxi, takeoff and landing and during sustained turbulence it is required that passenger restraints be fully fastened. A seat for an aircraft that can recline to a horizontal bed must have effective occupant restraints throughout its movement.

Usually these can be three point shoulder harness as in cars or, as more commonly used within aircraft, of the two point lap belt type. These lap belts must be able to restrain a range of occupants from a 5 year old child to a 95th percentile adult male. To ensure an effective restraint the belt must take the loads through an angle less than 55° from the horizontal, with the belt anchor within a maximum distance of 2" forward of the SRP (seat reference point) when the seat is in a position for taxi, takeoff or landing.

With the lap belt system, the maximum loads transmitted through lap belts occur when the seated occupant and seat are in the upright position i.e. during taxi, take-off and landing. In all positions, including the semi-reclined and bed positions, the occupant and seat structure are subject to in-flight turbulence and gust loads.

These loads are much less severe, so less strength is required of the load bearing structure that supports the occupant when in the semi-reclined and bed positions, and so the structure may weigh less. Aircraft seats are subject to weight restrictions and lower weight is related to lower operational costs.

When a seat recline apparatus is arranged by using a carriage to carry the occupant from upright to the bed position, it is necessary to have the lap belt anchor points attached to and able to move with the upper part of the seat carriage assembly and capable of coping with the gust loads in all positions. In the upright position they should be attached positively to the lower fixed part of the carriage, thereby creating one unit, transferring the considerably higher lap belt loads via the seat structure base frame directly to the aircraft load bearing structure or the floor rails.

Airlines are increasingly using staggered seating arrangements for their First and Business class cabins. The staggered seating system is proven to be the most efficient way of increasing comfort and obtaining more usable space. In some cases, for example when coupled with overlapping armrests and especially by using the aircraft 3° from horizontal in-flight floor condition, seats that convert to horizontal flat beds can also be overlapped. This involves the seats being moved further apart and having a wider console between adjacent seats. The lateral offset between seat rows means that each passenger sits directly behind a console in the preceding seat row. For the occupant behind, this wider console can be used as a footwell for their legs and feet when reclined, thus reducing seat pitch between rows and gaining more rows therefore more seats per aircraft.

In the reclined/bed position the leg support and a portion of the front of the seat base cushion surface extend into the footwell in the preceding seat row. The lateral offset of the seats means that the outer parts of the legrest and base cushion of the reclined seat occupy the same area as the outer rear corners of the base cushion (when the seat is upright) and backrest (when the seat is reclined) of the preceding seat when seen in plan view. This overlap is made feasible by the in-flight 3° angle allowing the most forward components of the aft seat to arrive under the rearmost components of the forward seat. The advantages are a horizontal bed with ample shoulder and seat width, a narrower but adequate foot well width and height beneath the wider console.

Since part of the space under each side of each seat base cushion must be reserved for occupation by the legrest and seat cushion of the reclined seat from the following row, the space available to house the apparatus required to move a seat and occupant from an upright to a bed position will be substantially narrower than the width of the seat cushion surfaces. The lap belt anchors should have their upper ends positioned generally at each side of the base cushion surface to ensure effective restraint of the full range of seat occupant sizes. The lower end of the lap belt anchors should be attached to the upper part of the seat recline apparatus without increasing its width.

The recline apparatus, which enables the movement of the seat from upright through recline to a bed position, generally comprises a sliding upper carriage on a linear slide attached to a fixed lower structure that is connected to aircraft floor structure. At any position within its full range of movement the upper carriage may be stopped at the whim of the passenger, and must be securely retained against inadvertent movement. In the case of a manually operated recline system this may be achieved by means of a system of spring-loaded teeth and slots similar to a manual car seat adjuster. If the recline motion is to be operated using a motor and reduction gear system, the force required to back drive the unpowered motor is normally sufficient to prevent movement of the carriage. Except for TTL (taxi, takeoff or landing) the loads that might cause the carriage to move are in the order of 1.5G-2G in a forward or aft direction. For TTL the loads that must be sustained are 9G (static) or 16G (dynamic) in the forward direction and 1.5G in the aft direction.

An apparatus for prevention of unintentional movement of the carriage against TTL loads would be substantially heavier than one that is only required to withstand in-flight and gust loads. Because the higher strength is only required with the seat in its TTL configuration, it would be feasible to use a lower strength apparatus and to cater for crash loadings with a mechanism which locks together the moving and fixed parts of the recline apparatus when in the TTL position.

This could be achieved by use of appropriately positioned holes and spring loaded pins, for example on both sides of the recline apparatus, where the pins are able to engage in the holes when the seat is in its TTL position. To move the seat away from the TTL position the pins must be retracted from the holes.

Disadvantages of this locking method include difficulties in reliably engaging the lock on both sides of the recline apparatus and the need for additional mechanisms to withdraw the pins and allow the seat to be moved away from the TTL position.

It would be desirable to provide an improved means of locking a seat's moving recline carriage to the fixed lower structure.

SUMMARY OF THE INVENTTON

Accordingly, a first aspect of the invention provides a load handling apparatus for a reclinable passenger seat, especially an aircraft seat, the seat being movable with respect to a base between non-reclined and reclined states and having a passenger restraining belt, the load handling apparatus comprising: at least one belt anchor for fixing said restraining belt to said seat, said at least one belt anchor being coupled, in use, to said seat and operable between a non-locking state and a locking state; a first interlocking member provided on said at least one belt anchor; a corresponding second interlocking member provided in use on said base, wherein, in the non-locking state, said first interlocking member is arranged so that it does not interlock with said second interlocking member and, in said locking state, said first interlocking member interlocks with said second interlocking member to prevent movement of said seat with respect to said base, and wherein, said at least one belt anchor is operable from said non-locking state to said locking state in response to a load exerted on said at least one belt anchor, in use, by said restraining belt.

A second aspect of the invention provides a seat unit, especially for an aircraft, comprising a reclinable passenger seat that is movable with respect to a base between non-reclined and reclined states and has a passenger restraining belt, the seat unit further comprising the load handling apparatus of the first aspect of the invention.

A third aspect of the invention provides a vehicle, especially an aircraft, comprising at least one seat unit of the second aspect of the invention.

Preferably, said at least one belt anchor is arranged to maintain said non-locking state when said load is less than a threshold level, and to adopt state locking state when said load exceeds said threshold level.

Advantageously, said load handling apparatus includes means for retaining said at least one belt anchor in said non-locking state, said retaining means being responsive to said load to allow said at least one belt anchor to adopt said locking state when said load exceeds said threshold level. Said retaining means may for example comprise a friction coupling between said at least one belt anchor and said seat, whereby friction forces created in said coupling during use maintain said at least one belt anchor in said locking state until said load exceeds said threshold level. Alternatively, or in addition, said retaining means may comprise at least one shear pin or other frangible device. The shear pin or other frangible device may be coupled between the at least one belt anchor and the seat in any convenient manner.

In preferred embodiments, the arrangement of said first and second interlocking members is such that they are capable of interlocking when, and preferably only when, said seat adopts a non-reclined state, especially the TTL position. Hence, excess loads that are exerted on the restraining belt, for example during a crash, cause the interlocking members to interlock thereby causing the load to be transferred to the base, and holding the seat in the non-reclined state.

Preferably, said at least one belt anchor is pivotably coupled to said seat and is pivotable between said non-locking and locking states. Conveniently, said at least one belt anchor comprises a lever being pivotably coupled to said seat at a point intermediate said first interlocking member and means for connecting to said restraining belt.

In the preferred embodiment, said first interlocking member comprises a hook, or other female interlocking member, and said second interlocking member comprises a retaining pin, or other male interlocking member. In alternative embodiments, this arrangement may be reversed. The preferred arrangement is such that, when said at least one belt anchor is in the non-locking state, the male and female interlocking members do not interlock in any of the seat's positions.

Hence, movement of the seat between the reclined and non-reclined states is unimpeded by the interlocking members and the load exerted by the restraining belt is borne by the seat via the at least one belt anchor. When said at least one belt anchor is in the locking state, the male and female interlocking members interlock. Preferably, the interlocking is capable of taking place when the seat is in its non-reclined state. In preferred embodiments, when the at least one belt anchor is in the non-locking state, the male and female interlocking members are interposed when the seat is in the non-reclined, or TTL state, but to do not interlock and so do not prevent the seat from moving between the reclined and non-reclined states. When the at least one anchor is in the locking state, the male and female interlocking members remain interposed, but their relative position and/or orientation changes such that they interlock and prevent movement of the seat out of its non-reclined state.

To this end, in the case where the female interlocking member is provided on said at least one seat anchor, the arrangement is preferably such that the male interlocking member is located within, but not interlocked with, the female interlocking member when the seat is in its non-reclined state and said at least one seat anchor is in the non-locking state, and wherein, when said at least one seat anchor is in the locking state, the orientation of the female interlocking member is changed to retain said male interlocking member within said female interlocking member. In the case where the male interlocking member is provided on said at least one seat anchor, the arrangement is preferably such that the male interlocking member is located adjacent the female interlocking member when the seat is in its non-reclined state and said at least one seat anchor is in the non-locking state, and wherein, when said at least one seat anchor is in the locking state, the male interlocking member enters and is retained by said female interlocking member. In either case, the interlocking members are interlocked at least to the extent that movement of the seat out of the non-reclined state is prevented and that the load is transmitted to said base.

Preferably, latching means are provided to maintain said at least one belt anchor in the locking state. The latching means may take any suitable form, for example a ratchet mechanism incorporated into the coupling between said at least one belt anchor and said seat.

Preferred embodiments of the invention described herein provide means for locking a seat's movable recline carriage to a fixed lower structure. Loads are transmitted from the passenger restraint lap belts through reclining apparatus to the load bearing structure of the vehicle during a crash situation.

In typical embodiments, the seat is coupled to the base by a reclining apparatus (which may be considered to be part of the seat). The reclining apparatus typically includes a movable top carriage assembly, which carries the seat and also the belt anchor(s). When the apparatus is in the upright position (TTL), the hook can be engaged or latched on to a retaining pin mounted on a stationary lower carriage assembly (which is carried by the base). This hook or latch adopts an un-latched position in normal use and a latched condition only occurs when a significant load is applied to the hook/latch, via the lap belts. In the event of, for example, a crash, a predefined lap belt tension load would override a shear pin (or other frangible retaining means) arranged on the hook/latch thereby rotating the hook to its latched position and so allowing the transmission of the passenger restraint loads through the seat structure to the aircraft floor. Alternatively, the normal unlatched condition could be maintained by clamping the moving latch part with a level of friction that will not be overcome except by crash loading. The recline apparatus, lap belt anchors, backrest seatpan and legrest surfaces travel through defined points to ensure they do not strike or interfere with the seat recline apparatus positioned in front or behind whether in upright, in bed positions, or anywhere between.

The preferred mechanism comprises a respective retaining pin provided on either side of each fixed lower structure and a corresponding hook component provided on either side of the moving recline carriage, the hooks having their open end oriented so as to allow free movement of the recline carriage in normal conditions.

The upper end of each hook component carries the lower attachment of one side of the lap belt restraint. Attachment of each hook to the carriage may be by a single bolt or pin located between the lap belt attachment and the open end of the hook, and arranged such that a tension load applied to the lap belt rotates the hook around its corresponding pin. The hook can be restrained against rotation at lower levels of lap belt tension by friction if the pivoting attachment is clamped tightly or by the addition of additional sacrificial fastenings that fail by shearing at predetermined levels of lap belt tension. An alternative embodiment has the hook component built into the fixed part of the seat structure with the mating pin incorporated into the lower end of the lap belt anchor.

Embodiments of the invention are particularly suited for use with a seating system having seats arranged in multiple rows such that passenger positions in any seat row are laterally offset with respect to those in preceding or following seat rows.

The space between passenger places in forward seat rows is used to allow seats to be reclined to a substantially flat bed position so that the lower part of the reclined passenger arrives between the passengers of the preceding seat row. Preferably, the width of the passenger space and the lateral offset of the passenger positions are chosen such that there is a lateral overlap between the forward space required for a reclined passenger and the space required for the cushion, or seat base, of an upright passenger in a preceding seat row, thereby reducing the overall width of each seat.

Embodiments of the invention are particularly suited for use with a seating system in which the seat recline adjustment is achieved by coordinated movement of the connected seat components through paths that ensure that the moving seat components arrive in their correct (and preferably overlapped) positions without interference between the parts of successive seat rows. Typically, the recline apparatus fits within a space narrower than the seat cushion (or seat base) and supporting structure so as to allow lateral overlap of the passenger space in successive seat rows. In such cases, the seat belt anchor(s) are typically bent to extend between the side of the seat base and the recline apparatus.

The recline apparatus is typically not required to withstand crash loads when adjusted away from its upright (TTL) position. Advantageously, crash loads from the passenger restraint are transmitted through interlocking components that can only be engaged in the TTL position. Conveniently, the interlocking action of the crash load transmission components is initiated directly by increasing tension in the passenger restraint. The interlocking action of the crash load transmission components is preferably inhibited at low load levels to allow movement of the seat between the TTL and reclined positions. For example, inhibition of the interlocking action of the crash load transmission components may be achieved by failure of a sacrificial component such as a shear pin.

Further advantageous aspects of the invention will become apparent to those ordinarily skilled in the art upon review of the following description of an embodiment of the invention and with reference to the accompanying drawings.

BRJEF DECPJPTION OF THE DRAWINGS

Embodiments of the invention will now be described in detail, by way of example, and with reference to the accompanying drawings in which: Figure 1 is 3/4 view from the front right of a double seat unit, with the right hand passenger place in a reclined position and the left hand passenger place in the upright position.

Figure 2 is a 3/4 view from the left/right rear of the double seat unit shown in Figure 1.

Figure 3 is a seating plan showing a seating arrangement for a business class zone of, by way of example, a Boeing B777 aircraft, using seats of the type shown in Figure 1 Figure 4 is a plan view of part of the seating plan of Figure 3 showing the upholstered, or passenger support, surfaces of three passenger places in the reclined position, two places being in a row ahead of the third seat, which is laterally staggered with its centreline between the two forward seats.

Figure 5 is a view from directly below the seat units shown in Figure 4, showing their supporting structure and mechanisms.

Figure 6 is a cross sectional view of one seating position through a plane parallel to the longitudinal centreline, showing the passenger support surface and the main components of the recline apparatus, including a load handling apparatus embodying one aspect of the invention. The seat is in the upright (TTL) position.

Figure 7 and Figure 8 are cross sectional views of one seating position, through the same plane as for Figure 6, but with the seat in a partially reclined and a fully reclined position respectively.

Figure 9 is a 3/4 view from the right rear showing three seating units, two in a row preceding the third, which is positioned laterally between the first two. The left hand seat of the forward row is upright, the right hand seat of the forward row is fully reclined and the second row seat is shown partially reclined.

Figure 10 and Figure 11 are 3/4 views from the left rear and right rear respectively, showing three seat units in the same arrangement as for Figure 9 except that the second row seat is shown fully reclined.

Figure 12 and Figure 13 are 3/4 views from the right rear showing the relationship of the forward parts of a second row seat with the footwell space and adjacent enclosure panels formed by the seats in the preceding row.

Figure 14 is a partial cross sectional view of a fully reclined passenger place viewed from behind and slightly above the passenger support surfaces.

Figure 15 is a cross sectional view from behind a double seat unit showing the relationship between the passenger spaces, the recline apparatus and the enclosing seat panels.

Figure 16 is a cross sectional view from the right side showing the relationship between reclined seating components in successive seat rows.

Figure 17 and Figure 18 are cross sectional views of a passenger place showing the seat in two different stages within its reclining movement.

Figure 19 and Figure 20 are cross sectional views from the right hand side of two successive seat rows showing the relative positions and paths of movement for a passenger place reclining into a forward footwell space.

Figure 21, Figure 22, and Figure 23 show dimensions and typical paths of movement for strategic points on the passenger supporting components.

Figure 24 shows the relationship for two successive seat rows of the paths of movement of the passenger support components as shown in Figure 22.

Figure 25 is a -3⁄4 view from the right and beneath a single passenger position shown in the fully reclined position.

Figure 26 is a 3/4 view from the front right of a single passenger position, with the seat in the upright position and the lower passenger supporting components omitted to allow sight of the recline apparatus components.

Figure 27 is a view from the right side of the interface between the hook attached to the lap belt anchor and the retaining pin with the seat in the TTL position and the latching movement of the hook indicated.

Figure 28 and Figure 29 are views from the right hand side showing the way in which increasing lap belt loads cause the engagement of the retaining pins with the hooks.

Figures 30 to 33 show a passenger seat including an alternative embodiment of a load handling apparatus embodying the invention.

DETATLED DESCRJPTION OF THE DRAWNGS

As shown in Figure 3, seats in the business class zone of an aircraft may provided in successive rows, with the passenger positions in each row being laterally off set with respect to preceding or following rows, so that the space between passenger places may be used to allow the passenger places in the following rows to be reclined to a full flat bed condition. The layout shown is for a Boeing B777 aircraft but similar arrangements are possible for other aircraft types and other seating zones. Embodiments of the present invention are suitable for, but not limited to, use in seating arrangements of the type shown in Figure 3.

Figure 1 and Figure 2 show a typical seat unit for accommodating two passengers, each passenger place comprising a backrest and headrest portion 31, a base portion 32 and a legrest portion 33 (at least some of which are typically upholstered or cushioned), located between enclosing footwell side panels 46, a console forward part 47, a console top tray 50, a footwell shelf 48 and a footwell ramp 52. The void formed above the ramp 52 and shelf 48, underneath the console top tray 50 and between the panels 46 of a preceding seat row enclose the footwell 49 which will be occupied by at least part of the forward extension of a reclined legrest 33 and base cushion 32.

A typical passenger seat place is shown in cross section in its upright (TTL) position in Figure 6, partially reclined in Figure 7 and in its fully reclined bed position in Figure 8. In this embodiment, the recline apparatus includes a base structure 45 supporting a fixed side plate, or other support member, 27 at either side of the apparatus. The base structure 45 incorporates multiple spreader components 29 which carry the hardware required to attach the seat to the aircraft floor. Each side plate 27 carries a telescopic slide 37 which in turn carries a movable carriage 23. A first link 20 and a second link 21 are pivotably coupled to the carriage 23. The links 20 and 21 are also pivotably coupled to a backrest frame which supports the upholstered backrest 31. At the upper end of the backrest frame 30 is a headrest pivot 43 to which is attached a headrest frame 42. Another link 26 is attached at its lower end to the carriage 23 and at its upper end to a seatpan frame 22 near to its front end. The aft end of the seatpan frame 22 is pivotably coupled to link 21 at a point between its upper and lower ends. The seatpan frame 22 supports the upholstered base cushion 32. This arrangement of links allows the backrest 31 to be adjusted towards (and out of) a reclined position while simultaneously the base cushion 32 moves forward slightly and the forward end of the base cushion 32 is lowered.

The angle of the backrest 31 relative to the carriage may be altered by adjustment of the length of a backrest recline actuator 35. The forward end of the actuator 35 is coupled to the seatpan frame 22 while its aft end is connected to a lateral actuating link 53 (visible in Figure 9), which is fixed between the lower end of each of links 20. The angle and position of the base cushion 32 relative to the backrest 31 is controlled by the geometry of the links 20, 21 and 26.

To allow the backrest 31 to be reclined without a clash with the fixed seat shroud 54, the carriage 23 is translated forward during the recline. In the example shown here this is achieved by driving a base recline actuator 36, which may be attached to the base structure 45 via a mounting bracket 44. The base recline actuator 36 typically drives a spur gear arrangement 40 (visible in Figure 25) which engages a toothed rack 38 (visible in Figure 25) attached to the carriage 23 parallel to the slide 37. The rack 38 is typically positioned above the spur gear arrangement 40.

It would be feasible to place the spur gears 40 above the rack 38 but this arrangement would be more susceptible to ingress of debris, which could hinder or prevent movement of the carriage 23.

Because the axis of the slide 37 is inclined downward (in the forward direction and with respect to the floor) at its forward end, the legrest 33 must be raised as the carriage 23 is moved forward. This is to avoid contact with the aircraft floor and the footwell ramp 52. The legrest 33 is attached at its upper end to a link 39, which in turn is connected to the seatpan frame at a pivot 41 located within the upholstered base cushion 32. The angle of the legrest 33 with respect to the seatpan 32 is adjusted by changing the length of the legrest actuator 34 which is attached between the seatpan 22 and the legrest 33.

As can be seen in Figure 9 through Figure 13, in the reclined state, the forward parts of each side of the base cushion 32 and legrest 33 arrive underneath the sides of the rear ends of the base cushion 32 of an upright seat in the preceding row, or underneath the sides of the headrest 42 and backrest 31 of a reclined seat in the preceding row.

Figure 19 is a lateral cross section of a fully reclined seat showing the passenger support surface provided by the backrest 31, base cushion 32 and legrest 33 aligned with the footwell shelf 48 of the preceding seat row. Figure 20 is a lateral cross section of the same pair of seat rows with the aft row shown in the upright position. To adjust the seat from the upright position to the reclined position the backrest 31, base cushion 32 and legrest 33 are moved in a coordinated manner such that the upper end of the headrest frame travels from point A to point B while the rear of the base cushion 32 travels from point C to point D, the upper forward edge of the cushion 32 travels from point E to point F and the lower front point of the legrest 33 travels from point G to point H. The paths of travel between these points may be straight lines or curved paths as shown in Figure 20 through Figure 24.

The cross sectional view from behind a double seat unit shown in Figure 15 illustrates that the width available for the recline apparatus 51 is less than the width of the base cushion.

A passenger seated on a seat of this type, or on other types of reclinable seats, is restrained against inertial loads by a seatbelt 24 each end of which is attached to a respective belt anchor 25 on either side of the passenger. Each belt anchor 25 is pivotally coupled to a respective side of the carriage 23. Because of the difference in width between the base cushion 32 and the recline apparatus 51 in this example, the belt anchor has a distinct "dog-leg" form when viewed from the front or rear.

The belt anchor 25 is adapted to form part of a load handling apparatus embodying one aspect of the present invention. As can best be seen from Figures 9, 25 and 26, each anchor 25 comprises first and second sections 25A, 25B that are obliquely disposed with respect to one another. Section 25A is adapted to receive a respective part of the belt 24 (and so preferably projects generally laterally from section 25B, preferably outwardly from the seat), while section 25B is pivotably coupled to the carriage 23. Section 25B also provides part of the load handling apparatus and includes a first interlocking member in the preferred form of a hook 25C (Figure 6), the pivot point typically being located between the hook 25C and the first portion 25A of the anchor. Typically, the hook 25C is below the pivot point, conveniently at the end of the anchor 25. The preferred arrangement in this embodiment is such that the open recess of the hook 25C faces generally rearwardly of the seat.

As can be seen in Figures 6 through 8 and in Figures 16 through 19 the hook 25C is shaped and oriented so that the seat may be moved between its upright (TTL) and reclined positions without hindrance from a second interlocking member, conveniently comprising a retaining pin 28, or other projection that projects laterally outwards from the seat. The retaining pin 28 is fixed with respect to the base structure 45 (provided on the respective side plate 27 in the present embodiment). Each belt anchor 25 is attached, or coupled, to the carriage 23 using a pivotable coupling 55 which may take the form of a bolted connection.

The normal orientation of the belt anchor 25 (as shown in say Figures 6 to 8) may be maintained by the clamping friction of the pivot 55, and/or by the incorporation into the connection between the anchor 25 and the carriage 23 of a sacrificial, or frangible, component such as a shear pin (not shown), and/or any other suitable load-sensitive means. The arrangement is such that the belt anchor 25 is caused to pivot with respect to the carriage 23 when a load, in particular an inertial load, is exerted on the anchor 25, and therefore on the pivot coupling 55, that exceeds a threshold level, e.g. a level of force that overcomes the frictional resistance of the coupling or the strength of the shear pin or other load-sensitive device. More particularly, the arrangement is such that the load, or force, exerted on the anchor 25 via the seatbelt 24, provides the operative force for causing movement of the pivot 55. The load handling apparatus is configured such that the threshold level is greater that the level that is experienced by the anchor 25 during normal operation of the vehicle, i.e. during TTL and normal flight, especially when the seat is in its TTL position. For example, the level of friction or the strength of the sacrificial component is chosen so that relatively low level inertial loads such as those experienced during normal operation of the aircraft would not cause a restrained occupant to generate sufficient tensile loads in the lap belt 24 SO as to cause the belt anchor 25 to rotate about its attachment pivot 55. However, the threshold level would be exceeded in the event of a crash or an emergency stop.

Figure 28 shows a cross section of a seat in the upright (TTL) position with the retaining pin 28 received in the hook 25C of the belt anchor 25, the hook being oriented to allow free movement of the carriage 23 into and out of the reclined state (and as such the hook 25C and pin 28 may be said to adopt a non-locking state). In circumstances where it might be expected that an aircraft would be exposed to inertial loads of a level sufficient to generate significant tension in the lap belt 24 (this would typically be loads with a forward component in excess of 2G), seats occupied by passengers would be placed in the upright (TTL) position.

When the tensile load on the lap belt increases above a predetermined level, the anchor 25 rotates (clockwise as shown in the drawings) about its pivot 55 allowing the hook 25C to wrap around the retaining pin 28 as shown in Figure 27 and Figure 29 (and as such the hook 25C and pin 28 may be said to adopt a locking state). This movement allows the passenger restraint loads to be transmitted through the retaining pins 28 to the seat base structure 45 and thereby to the aircraft floor. This is because the hook 25C, in its rotated position, is arranged with respect to the pin 28 such that the passenger restraining loads that are transmitted to the hook 25C urge the hook 25C into engagement with the pin 28. This arrangement also prevents movement of the seat away from its upright (TTL) position.

Referring now to Figures 30 to 33, there is shown an alternative embodiment of the load handling apparatus. The load handling apparatus is shown incorporated into a reclinable seat, in particular an aircraft seat, that may be similar to the seat depicted in Figures 1 to 29 and so like numerals are used to denote like parts and the same description applies as would be apparent to a skilled person. The seat has a backrest portion 131, a base portion 132 and a legrest portion 133 and is shown in its TTL state. The seat is mounted on a base structure 145 by a movable carriage 123, which is slidable back and forth as previously described. The seat belt anchor 125 is coupled to the carriage 123 by a pivotable coupling 155 that may be the same as the pivot 55 described above. Below the pivot 155, the anchor 125 has a first interlocking member in the form of a retaining pin 128, or other projection. The pin 128 projects laterally outwards away from the seat. The second interlocking member, which preferably comprises a hook 125C, is fixed with respect to the base structure 145. The open mouth of the hook faces forwardly of the seek in this embodiment.

Figure 30 shows the seat in normal use when the load exerted on the anchor 125 by the seatbelt is less than the threshold value needed to activate the load handling mechanism, i.e. loads that are experienced during normal TTL and flight. It can be seen that the pin 128 is located within the hook 125C but that its position within the hook 125C allows it to leave and re-enter the hook 125C as the carriage 123 moves back and forth with respect to the base structure 145, i.e. as the seat moves between its TTL and reclined states.

Figures 31 and 32 show the seat progressively after a load has been exerted on the anchor 125 that is sufficient to cause the anchor 125 to pivot about pivot 155. It can be seen that the pin 128 moves to a position within the hook 125C from where in cannot escape from the hook 125C upon movement of the carriage 123 towards the reclined state of the seat. This can be seen from Figure 33, where, following some movement of the carriage 123 towards the reclined state, the pin 128 engages with a lip 126 of the hook 125C. Upon such engagement, the carriage 123 is prevented from moving further towards the reclined state. Moreover, the load exerted on the anchor 125 is now transmitted through the load handling apparatus to the base structure 145 and so to the floor of the vehicle.

Optionally, the anchor 25, 125 may be resiliently biased to adopt its non-locking position by, for example, one or more springs, or other resilient biasing means.

The biasing means could conveniently be provided between the anchor 25, 125 and the carriage 123.

It will be apparent from the foregoing that preferred embodiments of the invention provide means for locking the recline apparatus for TTL by the incorporation of a system using retaining pins attached to, preferably, either side of the moving carriage which can be engaged by corresponding hook shaped components attached to the fixed portion of the recline apparatus (or vice versa). The hooks are arranged so that, in a non-locking state, the seat may be moved throughout its entire range from TTL to fully reclined (bed position) and back and so that the pins are fully entered into the hooks for TTL. Under circumstances when the inertia loads on the seat are within the normal range for flight and ground handling the orientation of the hook components is arranged so that the seat may continue to be moved through its recline motion. When the inertia loads applied to the seat exceed a pre-determined level the coupling for the anchor allows the hooks to move so that they are rotated around the centre of the locking pin, or the pin to move relative to the hook, thereby causing a locking state to be adopted and preventing further movement of the carriage. To ensure that the recline apparatus remains locked during the high inertial event it is preferred to provide a latching mechanism (not shown) for the hook movement (or otherwise for anchor movement), so that a variation in the applied load to a level within the normal in-flight range will not allow the pins and hooks to disengage. It is feasible to provide this locking system with the hook and fixed pin components transposed, i.e. the pins on the fixed structure and the hooks attached to the moving carriage.

It will be understood that the invention may be used with seats that move back and forth on a carriage without necessarily being reclinable. Tn such cases, the non-reclined, or TTL, states referred to herein may be substituted by a first position of the movable seat (typically the rear most position), and the reclined state may be substituted by a second position of the seat (typically the foremost position).

The invention is not limited to the embodiments described herein, which may be modified or varied without departing from the scope of the invention.

Claims

CLATMS: 1. A load handling apparatus for a reclinable passenger seat, the seat being movable with respect to a base between non-reclined and reclined states and having a passenger restraining belt, the load handling apparatus comprising: at least one belt anchor for fixing said restraining belt to said seat, said at least one belt anchor being coupled, in use, to said seat and operable between a non-locking state and a locking state; a first interlocking member provided on said at least one belt anchor; a corresponding second interlocking member provided in use on said base, wherein, in the non-locking state, said first interlocking member is arranged so that it does not interlock with said second interlocking member and, in said locking state, said first interlocking member interlocks with said second interlocking member to prevent movement of said seat with respect to said base, and wherein, said at least one belt anchor is operable from said non-locking state to said locking state in response to a load exerted on said at least one belt anchor, in use, by said restraining belt.
2. An apparatus as claimed in claim 1, wherein said at least one belt anchor is arranged to maintain said non-locking state when said load is less than a threshold level, and to adopt state locking state when said load exceeds said threshold level.
3. An apparatus as claimed in claim 2, wherein said threshold level is such that loads experienced by said at least one belt anchor during normal use of a vehicle in which said passenger seat is incorporated do not exceed said threshold level.
4. An apparatus as claimed in claim 2 or 3, wherein said load handling apparatus includes means for retaining said at least one belt anchor in said non-locking state, said retaining means being responsive to said load to allow said at least one belt anchor to adopt said locking state when said load exceeds said threshold level.
5. An apparatus as claimed in claim 4, wherein said retaining means comprises a friction coupling between said at least one belt anchor and said seat, whereby friction forces created in said coupling during use maintain said at least one belt anchor in said locking state until said load exceeds said threshold level.
6. An apparatus as claimed in claim 4 or 5, wherein said retaining means comprises at least one shear pin or other frangible device.
7. An apparatus as claimed in any preceding claim, wherein said first and second interlocking members are configured such that they are capable of interlocking when, and preferably only when, said seat adopts a non-reclined state.
8. An apparatus as claimed in any preceding claim, wherein said at least one belt anchor is pivotably coupled to said seat and is pivotable between said non-locking and locking states.
9. An apparatus as claimed in claim 8, wherein said at least one belt anchor comprises a lever pivotably coupled to said seat at a point intermediate said first interlocking member and means for connecting to said restraining belt.
10. An apparatus as claimed in any preceding claim, wherein said first interlocking member comprises a female interlocking member, preferably a hook, and said second interlocking member comprises a male interlocking member, preferably a retaining pin.
11. An apparatus as claimed in any one of claims 1 to 9, wherein said second interlocking member comprises a female interlocking member, preferably a hook, and said first interlocking member comprises a male interlocking member, preferably a retaining pin.
12. An apparatus as claimed in any claim 10 or 11, wherein, when the at least one belt anchor is in the non-locking state, the male and female interlocking members are interposed when the seat is in the non-reclined state, but to do not interlock and so do not prevent the seat from moving between the reclined and non-reclined states and, when the at least one anchor is in the locking state, the relative position and/or orientation of the male and female interlocking members changes such that they interlock to prevent movement of the seat out of its non-reclined state.
13. An apparatus as claimed in claim 10 or 12, wherein, when the seat is in a non-reclined state and said at least one seat anchor is in the non-locking state, the male interlocking member is located within, but not interlocked with, the female interlocking member, and wherein, when said at least one seat anchor is in the locking state, the orientation of the female interlocking member is changed to retain said male interlocking member within said female interlocking member.
14. An apparatus as claimed in claim 11 or 12, wherein, when the seat is in a non-reclined state and said at least one seat anchor is in the non-locking state, the male interlocking member is located within, but not interlocked with, the female interlocking member, and wherein, when said at least one seat anchor is in the locking state, the position of the male interlocking member is changed such that movement of the seat towards the reclined state causes the male interlocking member to engage with a lip of the female interlocking member and so to prevent further movement of the seat towards the reclined state.
15. An apparatus as claimed in any preceding claim, wherein latching means are provided to maintain said at least one belt anchor in the locking state.
16. A seat unit, especially for an aircraft, said seat comprising a reclinable passenger seat that is movable with respect to a base between non-reclined and reclined states and has a passenger restraining belt, the seat unit further comprising a load handling apparatus as claimed in claim 1.
17. A seat unit as claimed in claim 16, including a respective one of said load handling apparatus on either side of the seat unit.
18. A seat unit as claimed in claim 16 or 17, wherein said first and second interlocking members are arranged for interlocking when said seat is in its TTL (take off, taxi and landing) state.