Patent ID: 12246632

DETAILED DESCRIPTION

A seat cushion1in accordance with an embodiment of the present invention is described herein with reference to the accompanying Figures. As described herein, the stiffness of the seat cushion1can be adapted to suit specific requirements.

The seat cushion1in the present embodiment is disposed in a seat assembly2of a vehicle V. As shown inFIG.1, the vehicle V is an automobile in the present embodiment. The seat cushion1could be used in other types of vehicle V, such as a utility vehicle, a tractor unit, a train, a ship or an aircraft. The seat cushion1and the seat assembly2are described herein with reference to a reference frame comprising a longitudinal axis X, a transverse axis Y and a vertical axis Z. The vehicle V has a cabin C in which a plurality of the seat assemblies2are mounted. The cabin C has at least first and second doors D-n for ingress/egress. For the sake of brevity, only one of the seat assemblies2is described herein.

As shown inFIG.2, the vehicle seat assembly2comprises a seat base3and a seat back4. The seat cushion1in the present embodiment forms part of the seat base3. Alternatively, or in addition, the seat cushion1could form part of the seat back4. The seat cushion1is supported in the seat base3by a seat pan5mounted to a seat chassis (not shown). The seat chassis may be in the form of a seat frame or seat structure. The seat pan5comprises a plate member for supporting the seat cushion1. The seat chassis is mounted to the floor of the vehicle V. The seat chassis may enable the longitudinal and/or vertical position of the seat pan5to be adjusted relative to a floor of the vehicle V. As shown inFIG.3, the seat cushion1comprises a central seating region6and a thigh support7for supporting the thighs of a seat occupant. The position of the thigh support7relative to the central seating region6may be adjustable, for example to adjust the thigh support for the seat occupant. The vertical and/or longitudinal position of the thigh support7may be adjustable relative to the central seating region6. The seat back4comprises a frame (not shown) which supports a back-support cushion8and opposing lateral lumbar supports (not shown). The seat back4also comprises a head rest10. The seat back4may be pivotally mounted to the seat chassis to enable a recline angle of the seat back4to be adjusted relative to the seat base3. A first seat cover11is provided over the seat base3to protect the seat cushion1. A second seat cover12is provided over the seat back4. At least in certain embodiments, the vehicle seat assembly2may be selectively configurable in a deployed condition (for seating an occupant); and a stowed condition (for reducing the space occupied by the seat assembly). The vehicle seat assembly2is illustrated in the deployed condition inFIG.2. In the stowed condition, the seat back4is typically pivoted forwards such that the back-support cushion8faces the seat cushion1.

The composition of the seat cushion1will now be described. The seat cushion1comprises a compressible member15and at least one insert16. The compressible member15is a foam member. The or each insert16is at least partially encapsulated within the compressible member15. As described herein, the or each insert16is co-moulded with the compressible member15. The insert16is integral with the compressible member15. The compressible member15is moulded from a foaming material, such as a thermoplastic elastomer foaming material, which is introduced into a mould cavity51. The insert16is pre-formed and introduced into the mould cavity51prior to introduction of the foaming material. Thus, the insert16is at least partially encapsulated by the foam in the mould cavity51. The forming of the seat cushion1is described in more detail herein with reference toFIGS.5A,5B and5C. The compressible member15may comprise a foam having an open cell or a closed cell structure. The seat cushion1in the present embodiment comprises a single insert16which is encapsulated within the compressible member15. The insert16comprises at least one inflatable bladder17-n. The or each inflatable bladder17-ncomprises at least one port18-nfor connection to a pressurised gas supply, typically a pressurised air supply. The or each inflatable bladder17-nhas a multi-cell composition to promote inflation in a single axis. In the present embodiment, each inflatable bladder17-ncomprises first and second cells disposed on top of each other to promote expansion in a vertical axis.

The insert16comprises first and second inflatable bladders17-1,17-2which are inflatable independently of each other. The first inflatable bladder17-1is associated with a rear portion of the seating region6; and the second inflatable bladder17-2is associated with a front portion of the seating region6. In a variant, the second inflatable bladder17-2(and/or a separate inflatable bladder) may be associated with the thigh support7. The first and second inflatable bladders17-1,17-2have respective first and second ports18-1,18-2. The first and second ports18-1,18-2are positioned at a first end of the seat cushion1for location proximal to the seat back4in the seat assembly2. The first inflatable bladder17-1comprises a plurality of elongated first tubular members19-1, each of the first tubular members19-1being in fluid communication with the first port18-1. In the present embodiment, the first inflatable bladder17-1comprises six (6) of the first tubular members19-1, but less than six (6) and more than six (6) first tubular members19-1are also contemplated. The second inflatable bladder17-2comprises a plurality of elongated second tubular members19-2, the second tubular members19-2each being in fluid communication with the second port18-2. In the present embodiment, the second inflatable bladder17-2comprises six (6) of the second tubular members19-2, but less than six (6) and more than six (6) second tubular members19-2are also contemplated. In the present embodiment, the first and second tubular members19-1,19-2are arranged in pairs extending along a longitudinal axis.

As shown inFIG.3, a first supply line20-1connects the first tubular members19-1to each other and to the first port18-1. As shown inFIG.3, at least one second supply line20-2(shown in dashed lines) connects the second tubular members19-2to each other and to the second port18-n. The second inflatable bladder17-2comprises a plurality of second fluid supply lines20-2. The second fluid supply lines20-2extend along the length of a corresponding one of the first tubular members19-1and open into the second tubular members19-2. In a variant, the second inflatable bladder17-2may comprise a transverse line extending directly between the second tubular members19-2. The first and second inflatable bladders17-1,17-2are each formed by bonding first and second gas-impermeable sheet members to each other to form sealed (fluid-tight) join lines which define the first and second tubular members19-1,19-2. The first and second fluid supply lines20-1,20-2may be formed integrally with the first and second inflatable bladders17-1,17-2, for example by forming sealed join lines. Other techniques may be employed to form the first and second tubular members19-1,19-2. The first and second ports18-1,18-2are bonded to the sheet members, for example using an adhesive or thermal bonding agent.

The seat cushion1comprises a plurality of chambers21associated with the or each inflatable bladder17-1,17-2. In the present embodiment, the chambers21are formed below the or each inflatable bladder17-1,17-2. The chambers21are hollow voids formed within the compressible member15. In the present embodiment, one of the chambers21is formed adjacent to each of the tubular members19-1,19-2. The or each chamber21is pre-formed within the compressible member15and functions as an expansion chamber into which the associated inflatable bladder17-1,17-2can expand. By pre-forming the at least one chamber21, the inflatable bladder17-1,17-2can expand within the compressible member15. At least in certain embodiments, this expansion can occur with reduced or minimal localised compression of the compressible member15. The insert16comprises one or more support elements22. The or each support element22is configured to form a lining of an associated one of the chambers21formed in the compressible member15. In the present embodiment, the insert16comprises a plurality of support elements22each associated with a respective one of the first and second tubular members19-1,19-2. The support elements22each comprise a sleeve which forms a pocket24which is open at a proximal first end and closed at a distal second end. In a variant, the pocket24may be open at both the first and second ends. The support element22may be formed integrally with the insert16, for example from one of the sheet members used to form the first and second inflatable bladders17-1,17-2.

The seat cushion1is injection moulded in a mould50. The compressible member15is moulded from a foaming material and, as described herein, the insert16is at least partially encapsulated therein. The fabrication process will now be described with reference toFIGS.5A,5B,5C,5D and5E. As shown inFIG.5A, the mould50is opened and the insert16located in a mould cavity51. A support assembly52is provided to support the insert16in the desired location within the mould cavity51. The support assembly52is movable between a first position for performing the moulding process, and at least one second position for removal/insertion of the moulded seat cushion1. The support assembly52is pivotally mounted to enable movement between the first and second positions. In use, the support assembly52pivots through an angle of between 30° and 45° as it moves between the first and second positions. Alternatively, or in addition, the support assembly2may translate between the first and second positions. The support assembly52comprises a plurality of support arms53arranged to locate within respective pockets24formed by the support elements22. The support arms53are inserted through the open first end25of each pocket24. The support arms53are profiled to expand the pockets24formed in the insert16. An end view of the support arms53disposed in the pockets24is shown inFIG.5A. A releasable retaining device, such as a vacuum pump may optionally be used to retain the insert16on the support assembly52. The support arms53are configured to form the chambers21within the compressible member15. In particular, the support arms53are sized to expand the pockets24when the insert16is disposed on the support assembly52.

The support assembly52is secured in the first position within the mould cavity51and the mould closed, as shown inFIG.5B. The foaming material is introduced into the mould cavity51to form the compressible member15. The foaming material at least substantially fills the mould cavity51. The foaming material fills the region around the first and second tubular members19-1,19-2, thereby at least partially encapsulating the insert16. The foaming material cures and the mould cavity51is opened. The support assembly52is displaced from the first position to the second position. As shown inFIG.5C, the seat cushion1is removed from the mould cavity51by sliding the seat cushion1off the support assembly52. The support arms53are removed from the pockets24, thereby opening the chamber(s)21within the compressible member15. The support element22prevents or reduces contact between the foaming material and the support arms53thereby facilitating removal of the seat cushion1from the support assembly52. The insert16is co-moulded into the compressible member15of the seat cushion1. The pockets24are disposed on an upper side of the insert16such that the chambers21are formed above the insert16. In a variant, the pockets24may be disposed on an underside of the insert16such that the chambers21are formed below the insert16. The insert16may optionally comprise one or more interlocking features to secure the insert16in the compressible member15.

In accordance with some embodiments of the present invention, and as illustrated inFIGS.5D and5E, during the moulding process first and second ports18-1,18-2may be held within a locating element18-3. The locating element18-3is configured to be located within the mould50and during the moulding process to accurately locate and hold in place the first and second ports18-1,18-2and the ends of the supply lines20-1,20-2connected thereto. During the moulding process, the locating element18-3is only partially encapsulated within the compressible member such that once the seat cushion1has been removed from the mould cavity51the first and second ports18-1,18-2are accessible for subsequent connection to a pressurised gas supply.

Advantageously, the locating element18-3enables the ends of the first and second ports18-1,18-2and the ends of the supply lines20-1,20-2connected thereto to be accurately located and held in place during the moulding process without squashing the ports18-1,18-2and the supply lines20-1,20-2, and helps to prevent the foaming material entering the ports18-1,18-2and the supply lines20-1,20-2during the moulding process.

In some embodiments, the locating element18-3may comprise a polyurethane block. In addition, the foaming material used for the compressible member15may comprise expanded polyurethane. In this manner, the locating element and foaming material bond together during the moulding process to facilitate retention of the locating element18-3within the compressible member15.

Once the seat cushion1has been moulded, the first and second inflatable bladders17-1,17-2are inflated by introducing pressurised gas through the first and second ports18-1,18-2. In the present embodiment, the first and second inflatable bladders17-1,17-2are pneumatic bladders for inflation with pressurised air. The first and second tubular members19-1,19-2inflate at least partially to fill the chambers21formed in the compressible member15. The properties of the seat cushion1can be controlled in dependence on the inflation pressure of the first and second inflatable bladders17-1,17-2. A target inflation pressure may be specified for the first inflatable bladder17-1and/or the second inflatable bladder17-2. The target inflation pressure may be specified by a user, for example using an input device; or by a vehicle system, for example in dependence on a current driving mode of the vehicle V. In the present embodiment, the inflation pressure is controllable to enable dynamic adjustment of the properties of the seat cushion1, for example controllably to increase or decrease stiffness. The first and second ports18-1,18-2are configured to be connected to a pressurised air supply28for supplying pressurised air to inflate the first and second inflatable bladders17-1,17-2. The pressurised air supply28comprises an air compressor29and at least one reservoir30. The pressurised air supply28comprises first and second connectors31-1,31-2for connection to the first and second ports18-1,18-2. First and second valves32-1,32-2are provided for controlling the supply of pressurised air to the first and second inflatable bladders17-1,17-2. The first and second valves32-1,32-2are associated with the first and second ports18-1,18-2respectively. The first and second valves32-1,32-2are two-way valves which can be selectively opened and closed to control inflation and deflation of the first and second inflatable bladders17-1,17-2. The first and second valves32-1,32-2are operable independently of each other to enable control of the inflation pressure of each of the first and second inflatable bladders17-1,17-2. The first and second inflatable bladders17-1,17-2may have the same or different inflation pressures. The seat cushion1could optionally include one or more pressure sensors (not shown) for measuring the pressure in the first and second inflatable bladders17-1,17-2. In a variant, the inflation pressure of the first and second inflatable bladders17-1,17-2may be fixed, for example by sealing the first and second ports18-1,18-2when the first and second inflatable bladders17-1,17-2have been inflated to the desired inflation pressure.

The process of integrally forming the compressible member15and the insert(s)16is represented by a block diagram100shown inFIG.6. The insert(s)16is disposed in the mould cavity51(BLOCK105). As described herein, the or each insert16is disposed on a support arm53. The support arm53is introduced into a pocket24formed in each insert16. The or each pocket24is thereby expanded by the support arm53. In some embodiments, the locating element18-3is located within the mould50(BLOCK110) to locate and hold in place the first and second ports18-1,18-2and the ends of the supply lines20-1,20-2connected thereto. A foaming material is introduced into the mould cavity51to form the compressible member15(BLOCK115). The foaming material introduced into the mould cavity51at least partially encapsulates the at least one insert16. The foaming material is allowed to cure (BLOCK120). The compressible member15is removed from the mould cavity51(BLOCK125).

According to some embodiments, the vehicle V comprises means for determining an occupancy status of the seat assembly2. The occupancy status may indicate that the seat assembly2is either in a seat occupied state (i.e. the seat assembly2is occupied) or a seat unoccupied state (i.e. the seat assembly2is unoccupied). The occupancy determining means comprises one or more seat occupancy sensor25for detecting the presence or absence of a seat occupant. In the present embodiment, the seat occupancy sensor25comprises a load sensor for detecting a load (or weight) indicative of a person sitting in the seat assembly2. The seat occupancy sensor25is disposed in the central seating region6of the seat assembly2, for example below the seat cushion15. It will be understood that a seat occupancy sensor25may be provided for one or more of the vehicle seats2disposed in the vehicle V. The occupancy status may be determined in respect of one or more of the vehicle seats2in the vehicle V. The seat occupancy sensor25is configured to output a seat occupancy status signal SOCC indicating the occupancy status of the seat assembly2. Other types of sensor, such as a pressure sensor, may be used as the seat occupancy sensor25. In a variant, the seat occupancy sensor25may comprise or consist of an imaging system comprising one or more camera, for example comprising an optical camera or a thermal imaging camera.

In a variant, the seat occupancy sensor25may be implemented by an in-cabin imaging system (not shown). The cabin imaging system may be configured to determine the occupancy status of one or more of the vehicle seats2. The cabin imaging system may comprise at least one imaging sensor, such as an optical or thermal camera, for determining when one or more person is within the cabin of the vehicle V. The at least one imaging sensor can be arranged to capture an image of an interior of the cabin. The imaging sensor may be disposed in an upper region of the cabin of the vehicle V, for example mounted in a headlining, or disposed in a housing of a rear-view mirror; or may be disposed in an instrument panel or a dashboard of the vehicle V. The cabin imaging system may comprise an image processor for determining the occupancy status of the seat assembly2. The image processor may process image data captured by the at least one imaging sensor in order to identify the presence or absence of a person in a region associated with one or more of the vehicle seats2. The image processor may thereby determine an occupancy status of one or more of the vehicle seats2.

In the present embodiment, the vehicle V comprises a remote access system26for implementing remote control of one or more vehicle systems. The remote access system26may, for example, comprise a Passive Entry Passive Start (PEPS) system or an enhanced Passive Entry Passive Start (ePEPS) system. The remote access system26may control one or more door lock or security latches for securing the vehicle doors D-n. The latch(es) may, for example, be unlocked when the remote access system26is activated. The remote access system26in the present embodiment comprises a base unit27A provided in the vehicle V and a remote control unit27B, for example comprising a key fob or a cellular telephone. A user may activate the remote control unit27B to unlock one or more of the vehicle doors D-n. Alternatively, or in addition, the activation may be performed automatically when the base unit27A detects the remote control unit27B. The base unit27A and the remote control unit27B may perform an electronic handshake to determine that the remote control unit27B is associated with the vehicle V. If the electronic handshake is successful, the base unit27A is configured to output an access signal SACC to unlock one or more of the vehicle doors D-n. In a variant, the remote access system26could be configured to release a door opening mechanism at least partially to open the vehicle door D-n.

A control system33is provided for controlling operation of the first and second valves32-1,32-2. The control system33is provided in the vehicle V, for example as a module with a vehicle system controller, and connected to the seat assembly2. In a variant, the control system33could be incorporated into the seat assembly2, for example in a seat control panel. The control system30is configured to generate first and second control signals SOUT1, SOUT2 for controlling operation of the first and second valves32-1,32-2. When activated, the control system33is configured to open the first and second valves32-1,32-2to inflate the first and second inflatable bladders17-1,17-2. The control system33is configured to close the first and second valves32-1,32-2when the first and second inflatable bladders17-1,17-2are at respective target inflation pressures. The control system33may determine the inflation pressure of the first and second inflatable bladders17-1,17-2in dependence on a signal from one or more pressure sensors. Alternatively, the control system33may control the inflation pressure of the first and second inflatable bladders17-1,17-2by opening the first and second valves32-1,32-2for a predetermined period of time. The control system33in the present embodiment is activated when the vehicle V is unlocked or a door of the vehicle V is opened. The seat cushion1may be pre-conditioned to receive an occupant upon entering the vehicle V. The inflation of the first and second inflatable bladders17-1,17-2may reduce or minimise sagging of the first seat cover11, thereby improving the appearance of the seat assembly2. A perceived quality of the seat cushion1may be improved. The control system33may optionally be configured to reduce the inflation pressure when an occupant sits in the seat assembly2. The controlled reduction in the inflation pressure may provide a seat welcome feature on initial sit-in via the relaxing effect of the partial or complete deflation of the first and second inflatable bladders.

The seat assembly2is installed in the vehicle V and the pressurised air supply28is connected to the first and second inflatable bladders17-1,17-2via the first and second ports18-1,18-2. The control system33is activated and outputs the first and second control signals SOUT1, SOUT2 to open the first and second valves32-1,32-2. The pressurised air supply28supplies pressurised air and inflates the first and second inflatable bladders17-1,17-2. The first and second valves32-1,32-2may be operated in parallel, such that the first and second inflatable bladders17-1,17-2are inflated concurrently; or may be operated sequentially, such that the first and second inflatable bladders17-1,17-2are inflated one after the other. The control system33outputs the first and second control signals SOUT1, SOUT2 to close the first and second valves32-1,32-2when the first and second inflatable bladders17-1,17-2have been inflated to the desired inflation pressure. A user may optionally control the inflation pressure of the first and second inflatable bladders17-1,17-2, for example to increase or decrease the inflation pressure(s) of each of the first and second inflatable bladders17-1,17-2.

The second inflatable bladder17-2shown inFIG.3comprises a plurality of second tubular members19-2extending in a longitudinal direction. In a variant, the second inflatable bladder17-2may comprise one or more tubular members19-2which extend in a transverse direction. This arrangement is illustrated inFIGS.7and8. A perspective view of the compressible insert15with the insert16omitted is shown inFIG.9. The control system33can be configured to vary the inflation pressure of the first and second inflatable bladders17-1,17-2to provide a control function to provide an anti-fatigue (massage) function for a seat occupant. In particular, the inflation pressure of each of the first and second inflatable bladders17-1,17-2can be increased and decreased sequentially. By alternating the inflation and deflation of the first and second inflatable bladders17-1,17-2out of phase with each other, the seat cushion1induces a pitching hip motion for an occupant of the seat assembly2. The seat cushion1can be modified also to provide a rolling hip motion for the occupant. The anti-fatigue function provides an oscillation cycle which may provide longer-term comfort and may mitigate the effects of back discomfort, via oscillation of the spine and surrounding muscular tissue. At least in certain embodiments, the anti-fatigue function may induce a rhythmic motion of the hips and/or spine of the occupant which is representative of the motion occurring when a person is walking. The oscillation cycle could, for example, have an operating frequency of 20 to 100 cycles per minute, for example 50 cycles per minute. It is believed that this may enhance spinal lubrication and/or increase blood flow compared to a static posture.

A further operation of the control system33in relation to the seat assembly2according to some embodiments of the present invention will now be described in more detail. It will be understood that the same control strategy may be applied for more than one of the vehicle seats2.

The seat assembly2may be prone to sag over time due to a reduction in the tautness of the first seat cover11. A schematic representation of sag in the first seat cover11is shown inFIG.10A. Sag may be caused by stretching or deformation of the first seat cover11, for example due to repeated or prolonged use. Alternatively, or in addition, sag may be caused by deformation of the compressible member15, for example due to localised or repeat loading. The first seat cover11is subject to increased wear on the upper surface of the seat cushion1in the central seating region6. As illustrated inFIG.10A, sag of the first seat cover11is most prevalent in this upper seating region. Whilst not affecting the functionality of the seat assembly2, the sag in the first seat cover11may prove unsightly, particularly when the seat assembly2is unoccupied. The control system33is configured to control inflation of at least one of the first and second inflatable bladders17-1,17-2to reduce or prevent sag of the first seat cover11. In the present embodiment, the control system33is configured to increase the inflation pressure of at least one of the first and second inflatable bladders17-1,17-2to tension the first seat cover11, thereby reducing sag. At least in certain embodiments, the appearance of the vehicle seat1may be improved. A schematic representation of the reduced sag in the first seat cover11due to the increased inflation pressure of the first inflatable bladders17-1is shown inFIG.10B.

The sag of the first seat cover11is most apparent when the seat assembly2is unoccupied. To address this, the control system33is configured to increase the inflation pressure of at least one of the first and second inflatable bladders17-1,17-2in dependence on a determination that the seat assembly2is unoccupied. As outlined above, the seat occupancy sensor25outputs the seat occupancy status signal SOCC indicating the occupancy status of the seat assembly2(i.e. that the seat assembly2is occupied or unoccupied). The control system33reads the seat occupancy status signal SOCC to determine when the seat assembly2is unoccupied.

The determination that the seat assembly2is unoccupied provides an entry condition for controlling inflation of the first and second inflatable bladders17-1,17-2to reduce sag of the first seat cover11. The control system33is configured to control inflation of the first and second inflatable bladders17-1,17-2in dependence on the determination that the seat assembly2is unoccupied. The control system33identifies one or more trigger events which, in combination with the determination that the seat assembly2is unoccupied, prompt the control system33to increase the inflation pressure of at least one of the first and second inflatable bladders17-1,17-2. In the present embodiment, the activation of the remote control unit27B is the trigger event for initiating an increase in the inflation pressure of the first and second inflatable bladders17-1,17-2to reduce sag. The control system33receives the access signal SACC and checks the seat occupancy status signal SOCC to determine if the seat assembly2is occupied or unoccupied. If the control system33determines that the seat assembly2is unoccupied, the pressure increase signal SINC is generated to inflate the first inflatable bladder17-1and/or the second inflatable bladder17-2. As shown inFIG.10Bthe inflation of one or both of the first and second inflatable bladders17-1,17-2reduces the sag of the first seat cover11. It will be understood that other trigger events may be used to initiate inflation of at least one of the first and second inflatable bladders17-1,17-2. Other trigger events include one or more of the following: determination that the vehicle door D is unlocked; determination that the vehicle door D is opened; and/or determination that a handle associated with the vehicle door D is actuated.

The control system33is activated and generates the pressure increase signal SINC. The pressure increase signal SINC comprises at least one of the first and second control signals SOUT1, SOUT2 for controlling operation of the first and second valves32-1,32-2. The first and second valves32-1,32-2are opened in response to the first and second control signals SOUT1, SOUT2. The air supply28supplies pressurised air to the first and second inflatable bladders17-1,17-2, thereby increasing the inflation pressure of the first and second inflatable bladders17-1,17-2. The first and second valves32-1,32-2may be operated in parallel, such that the first and second inflatable bladders17-1,17-2are inflated concurrently; or may be operated sequentially, such that the first and second inflatable bladders17-1,17-2are inflated one after the other. For example, the first inflatable bladder17-1may be inflated before the second inflatable bladder17-2; or the first inflatable bladder17-1may be inflated after the second inflatable bladder17-2. Alternatively, the pressure increase signal SINC may selectively open only one of the first and second valves32-1,32-2. It is envisaged that the problem of sag of the first seat cover11will be more prevalent in the central seating region6of the seat assembly6. To counter sag in this region, the pressure increase signal SINC may consist of the first control signal SOUT1 to open the first valve17-1to inflate the first inflatable bladder17-1.

The control system33outputs the first control signal SOUT1 to close the first valve32-1when the inflation pressure of the first inflatable bladder17-2has increased to a first target inflation pressure. The control system33outputs the second control signal SOUT2 to close the second valve32-2when the inflation pressure of the second inflatable bladder17-2has increased to a second target inflation pressure. The first and second target inflation pressures may be the same as each other or different from each other. The degree to which sag occurs typically depends on the usage of the seat assembly2. Stretching of the first seat cover11may increase as a result of repeated or extended use of the seat assembly2resulting in increased sag. The control system33is configured to estimate usage of the seat assembly2and to set the first target inflation pressure and/or the second target inflation pressure in dependence on the estimated usage. In particular, the control system33is configured to increase the first target inflation pressure and/or the second target inflation pressure in proportion to the estimated usage. The usage may be estimated in dependence on one or more of the following factors: vehicle age; vehicle mileage; a cumulative time that the seat assembly2is occupied; the total number of times that the seat assembly2has been used, for example a number of ingress/egress cycles. The usage may be estimated for each seat assembly2in the vehicle2; or may be estimated collectively for two or more of the seat assemblies2.

The control system33pre-conditions the seat assembly2for the user. The increase in the inflation pressure of the first and second inflatable bladders17-1,17-2increases the volume of the seat cushion1and gently stretches the first seat cover11. The sag in the first seat cover11is thereby reduced and the appearance of the seat assembly2can be improved. The increase in the inflation pressure of the first and second inflatable bladders17-1,17-2may also increase the firmness of the seat cushion1. To improve comfort, the control system33is configured to reduce the inflation pressure of the first and second inflatable bladders17-1,17-2when an individual is seated on the seat assembly2. The control system33monitors the seat occupancy status signal SOCC to detect a change in the occupancy status. In particular, the control system33identifies a change from the seat unoccupied state to a seat occupied state which indicates that an individual is seated in the seat assembly2. In dependence on this change in the seat occupancy status, the control system33generates a pressure decrease signal SDEC to reduce the inflation pressure. The pressure decrease signal SDEC comprises at least one first control signal SOUT1 and/or a second control signal SOUT2 to open one or both of the first and second valves32-1,32-2to release air. The reduction in the inflation pressure of the first and second inflatable bladders17-1,17-2improves the comfort of the seat assembly2, for example helping to ease the individual into the seat assembly2.

The control system33may be configured controllably to decrease the inflation pressure of the first and second inflatable bladders17-1,17-2to achieve a target inflation pressure. The control system33may output the first control signal SOUT1 to close the first valve32-1when the inflation pressure of the first inflatable bladder17-2has decreased to a first target inflation pressure. The control system33may output the second control signal SOUT2 to close the second valve32-2when the inflation pressure of the second inflatable bladder17-2has decreased to a second target inflation pressure. The first and second target inflation pressures may be the same as each other or may be different from each other.

The control system33may be configured to identify or predict when the occupant is vacating the seat assembly2or is preparing to vacate the seat assembly2. The seat occupancy sensor25may detect an occupant movement or a change in the measured load, which is indicative of the occupant vacating the seat assembly2. To facilitate egress from the vehicle V, the control system33may generate a pressure increase signal SINC in dependence on the determination that the occupant is vacating the seat assembly2or is preparing to vacate the seat assembly2. By increasing the inflation pressure of the one or both of the first and second inflatable bladders17-1,17-2, the seat cushion1may help to lift or raise the occupant as they leave the seat assembly2.

This operation of the control system33will now be described with reference to a first block diagram100shown inFIG.11. The operation of the control system33is initiated (BLOCK205). The control system33monitors the seat occupancy status signal SOCC generated by the seat occupancy sensor25(BLOCK210). The control system33determines if the seat assembly2is occupied or unoccupied (BLOCK215). If the seat assembly2is occupied (OCC), the control system33continues to monitor the seat occupancy. If the seat assembly2is unoccupied (UNOCC), the control system33monitors one or more trigger event. One such trigger event in the present embodiment is activation of the remote access system26on the vehicle V. The base unit27A provided on the vehicle V outputs the access signal SACC (BLOCK220). In dependence on receipt of the access signal SACC, the control system33generates a pressure increase signal SINC (BLOCK225). The pressure increase signal SINC is output to the first and second valves32-1,32-2associated with the first and second inflatable bladders17-1,17-2respectively (BLOCK230). The pressure increase signal SINC opens the first and second valves32-1,32-2and pressurized air (i.e. air at greater than atmospheric pressure) is introduced into the first and second inflatable bladders17-1,17-2(BLOCK235). The control system33may optionally monitor (or estimate) the inflation pressure of the first and second inflatable bladders17-1,17-2. The first and second inflatable bladders17-1,17-2are inflated to respective first and second target pressures and the control system33outputs first and second control signals SOUT1, SOUT2 to close the first and second valves32-1,32-2(BLOCK240). The control system33monitors the seat occupancy status signal SOCC to determine when the seat assembly2is occupied (BLOCK245). In dependence on the change in the occupancy status of the seat assembly2, the control system33outputs the pressure decrease signal SDEC to reduce the inflation pressure of the first and second inflatable bladders17-1,17-2(BLOCK250). The control system33may optionally also identify or predict when the occupant is vacating the seat assembly, for example with reference to the seat occupancy sensor25. In dependence on identifying that the occupant is vacating the seat assembly2, the control system33generates the pressure increase signal SINC (BLOCK255). The process repeats until the control system33is deactivated (BLOCK260).

The control system33may be configured to selectively to inhibit generation of one or both of the pressure increase signal SINC and the pressure decrease signal SDEC. For example, the control system33may inhibit generation of one or both of the signals if a child seat is disposed on the seat assembly2. The control system33may, for example, utilise the seat occupancy sensor25to detect the presence or absence of a child seat. Alternatively, or in addition, a sensor may be provided to determine when a fastening mechanism in the seat assembly2is actuated to secure a child seat.

The second inflatable bladder17-2shown inFIG.3comprises a plurality of second tubular members19-2extending in a longitudinal direction. In a variant, the second inflatable bladder17-2may comprise one or more tubular members19-2which extend in a transverse direction. This arrangement is illustrated inFIGS.7and8. A perspective view of the compressible insert15with the insert16omitted is shown inFIG.9. The control system33can be configured to vary the inflation pressure of the first and second inflatable bladders17-1,17-2to provide a control function to provide an anti-fatigue (massage) function for a seat occupant. In particular, the inflation pressure of each of the first and second inflatable bladders17-1,17-2can be increased and decreased sequentially. By alternating the inflation and deflation of the first and second inflatable bladders17-1,17-2out of phase with each other, the seat cushion1induces a pitching hip motion for an occupant of the seat assembly2. The seat cushion1can be modified also to provide a rolling hip motion for the occupant. The anti-fatigue function provides an oscillation cycle which may provide longer-term comfort and may mitigate the effects of back discomfort, via oscillation of the spine and surrounding muscular tissue. At least in certain embodiments, the anti-fatigue function may induce a rhythmic motion of the hips and/or spine of the occupant which is representative of the motion occurring when a person is walking. The oscillation cycle could, for example, have an operating frequency of 20 to 100 cycles per minute, for example 50 cycles per minute. It is believed that this may enhance spinal lubrication and/or increase blood flow compared to a static posture.

In a further embodiment shown inFIG.12, the seat cushion1comprises first, second, third and fourth inflatable bladders17-1,17-2,17-3,17-4. The control system33is configured to control the inflation pressure of each of the first, second, third and fourth inflatable bladders17-1,17-2,17-3,17-4to provide a pitching hip motion and/or a rolling hip motion. The first and second inflatable bladders17-1,17-2are disposed on a first side of the seat cushion1; and the third and fourth inflatable bladders17-3,17-4are disposed on a first side of the seat cushion1. By alternating between inflation of one or more of the inflatable bladders17-1,17-2,17-3,17-4on the first and second sides, the control system can induce the rolling hip motion. Alternatively, or in addition, alternating between inflation of one or more of the inflatable bladders17-1,17-2,17-3,17-4at the front and back of the seat cushion1, the control system2can induce the pitching hip motion.

By way of example, the control system33may be configured to implement a control function comprising first and second operating cycles. The first operating cycle comprises inflating and deflating at least one of the first and second inflatable bladders17-1,17-2. The second operating cycle comprises inflating and deflating at least one of the third and fourth inflatable bladders17-3,17-4. The control system33controls the first and second cycles to induce a cyclical motion about a longitudinal axis X. This cyclical motion may induce a rolling motion of the hips of a seat occupant. Alternatively, or in addition, the control system33may be configured to implement a third operating cycle comprising inflating and deflating at least one the first and third inflatable bladders17-1,17-3; and a fourth cycle comprising inflating and deflating at least one of the second and fourth inflatable bladders17-2,17-4. The control system33controls the third and fourth cycles to induce a cyclical motion about a transverse axis Y. This cyclical motion may induce a pitching motion of the hips of a seat occupant.

It will be understood that the seat cushion1could be modified to combine the second and fourth inflatable bladders17-2,17-4such that the seat cushion1consists of three inflatable bladders17-1,17-2,17-3. In a further variant, the seat cushion1may comprise more than four (4) inflatable bladders17-1,17-2,17-3,17-4. In a further variant, the at least one inflatable bladder17-nmay be disposed in the seating region of the seat cushion1.

The control system33comprises one or more controllers34. It is to be understood that the or each controller34can comprise a control unit or computational device having one or more electronic processors (e.g., a microprocessor, a microcontroller, an application specific integrated circuit (ASIC), etc.), and may comprise a single control unit or computational device, or alternatively different functions of the or each controller34may be embodied in, or hosted in, different control units or computational devices. As used herein, the term “controller,” “control unit,” or “computational device” will be understood to include a single controller, control unit, or computational device, and a plurality of controllers, control units, or computational devices collectively operating to provide the required control functionality. A set of instructions could be provided which, when executed, cause the controller34to implement the control techniques described herein (including some or all of the functionality required for the method described herein). The set of instructions could be embedded in said one or more electronic processors of the controller34; or alternatively, the set of instructions could be provided as software to be executed in the controller34. A first controller or control unit may be implemented in software run on one or more processors. One or more other controllers or control units may be implemented in software run on one or more processors, optionally the same one or more processors as the first controller or control unit. Other arrangements are also useful.

In the example illustrated inFIG.13, the or each controller34comprises at least one electronic processor35having one or more electrical input(s)36for receiving one or more input signals SIN-n and one or more electrical output(s)37for outputting one or more output signals SOUT-n. The or each controller34further comprises at least one memory device38electrically coupled to the at least one electronic processor35and having instructions39stored therein. The at least one electronic processor35is configured to access the at least one memory device38and execute the instructions39thereon so as to perform the method(s) described herein.

The, or each, electronic processor35may comprise any suitable electronic processor (e.g., a microprocessor, a microcontroller, an ASIC, etc.) that is configured to execute electronic instructions. The, or each, electronic memory device38may comprise any suitable memory device and may store a variety of data, information39, threshold value(s), lookup tables or other data structures, and/or instructions therein or thereon. In an embodiment, the memory device38has information and instructions for software, firmware, programs, algorithms, scripts, applications, etc. stored therein or thereon that may govern all or part of the methodology described herein. The processor, or each, electronic processor35may access the memory device38and execute and/or use that or those instructions and information to carry out or perform some or all of the functionality and methodology describe herein.

The at least one memory device38may comprise a computer-readable storage medium (e.g. a non-transitory or non-transient storage medium) that may comprise any mechanism for storing information in a form readable by a machine or electronic processors/computational devices, including, without limitation: a magnetic storage medium (e.g. floppy diskette); optical storage medium (e.g. CD-ROM); magneto optical storage medium; read only memory (ROM); random access memory (RAM); erasable programmable memory (e.g. EPROM ad EEPROM); flash memory; or electrical or other types of medium for storing such information/instructions.

Example controllers34have been described comprising at least one electronic processor35configured to execute electronic instructions stored within at least one memory device38, which when executed causes the electronic processor(s)34to carry out the method as hereinbefore described. However, it is contemplated that the present invention is not limited to being implemented by way of programmable processing devices, and that at least some of, and in some embodiments all of, the functionality and or method steps of the present invention may equally be implemented by way of non-programmable hardware, such as by way of non-programmable ASIC, Boolean logic circuitry, etc.

It will be appreciated that various changes and modifications can be made to the present invention without departing from the scope of the present application. The inflatable bladders17-nhave been described herein as forming part of the same insert16. It will be understood that more than one inert16may be disposed in the compressible member15. Two or more inserts16may be incorporated into the compressible member15. The inserts16may each comprise one or more inflatable bladders17-n.

The seat cushion1could be moulded in the mould cavity51when the or each inflatable bladder17-nis inflated. The pre-inflation of the or each inflatable bladder17-nenables formation of the chamber(s)21during the moulding process.

The present invention has been described with particular reference to the first seat cover11provided on the seat base3. It will be understood that the present invention may also be applied to other parts of the seat assembly2. For example, one or more inflatable bladders may be provided in the seat back4. The control system33may be configured selectively to increase or decrease the inflation pressure in accordance with the method(s) described herein. Sag of the seat cover on the seat back4may be reduced. The seat assembly2may comprise one or more side bolsters, for example provided on the seat base3or the seat back4. One or more inflatable bladder may be provided in each side bolster. The control system33may be configured selectively to increase or decrease the inflation pressure in accordance with the method(s) described herein. Sag of the seat cover on the seat back4may be reduced.

As outlined above, the seating assembly2in certain embodiments may be selectively configurable in a deployed condition and a stowed condition in the vehicle V. The control system33may optionally be configured to detect whether the seating assembly2is in the deployed condition or in the stowed condition. The control system33can be configured to inhibit increases in the pressure of the one or more inflatable bladders19-nif the seat assembly is in the stowed condition. The control system33can be configured to detect a change from a stowed condition to a deployed condition; and/or from a deployed condition to a stowed condition. The control system33can be configured to increase the pressure of the one or more inflatable bladders19-nupon detecting a change in the condition of the seat assembly from the stowed condition to the deployed condition. The pressure of the one or more inflatable bladders19-nmay be increased once the seat assembly2is in the deployed condition or during the re-configuration of the seat assembly2to the deployed condition. The control system33can be configured to decrease the pressure of the one or more inflatable bladders19-nupon detecting a change in the condition of the seat assembly from the deployed condition to the stowed condition. The pressure of the one or more inflatable bladders19-nmay be decreased once the seat assembly2is in the stowed condition or as the seat assembly2is re-configured to the stowed condition.