GB2567425A

GB2567425A - A positioning system

Info

Publication number: GB2567425A
Application number: GB1716343.7A
Authority: GB
Inventors: Fillinger Tomas
Original assignee: Jaguar Land Rover Ltd
Current assignee: Jaguar Land Rover Ltd
Priority date: 2017-10-06
Filing date: 2017-10-06
Publication date: 2019-04-17
Anticipated expiration: 2037-10-06
Also published as: GB2567425B; GB201716343D0; DE102018216633A1

Abstract

A positioning system (3, figure 4) for a moveable vehicle seat assembly (17, 19), comprising an actuator (60) for moving at least one component (39, e.g. a bulkhead or partition) of the seat assembly between first and second positions, and a spring (74, 76) configured to bias the at least one component away from the second position. Preferably, a spring arrangement 72 comprises two clock torsion springs 74, 76 wound up in opposite directions to form a resilient coils. The first spring may store more energy than the second spring. Preferably first and second springs each have a handover position at which they cease biasing the component, e.g. by disengaging a protruding member 78 of the component. The spring arrangement 72 may work together with the actuator (60) to control movement of a bulkhead (8, figure 2) relative to a seatback or squab (24, figure 2). The elastic spring assistance may enable the actuator output to remain almost constant as the bulkhead moves between unfolded and folded positions. By modulating the actuator output, springs 74, 76 may allow the actuator to move quieter and prolong its working life.

Description

TECHNICAL FIELD

The present disclosure relates to a positioning system. In particular, but not exclusively, the present invention relates to a positioning system in a foldable seat assembly for use in the passenger compartment of a vehicle, for example a saloon car or sport utility vehicle (SUV). Aspects of the invention relate to a positioning system, a foldable seat assembly and a vehicle comprising a positioning system and/or a foldable seat assembly.

BACKGROUND

The large amount of space available in a standard sport utility vehicle (SUV) allows a user to reconfigure the seating of the SUV to either carry more passengers or to accommodate a larger load. However, the seats used in luxury SUVs, and luxury vehicles generally, are often larger and heavier than those used in standard passenger cars because they tend to be optimised for comfort rather than versatility.

Additional functionality may also be required from the seats of a luxury vehicle. For example, it may be desirable for a rear seat to have the ability to recline in order to afford more comfort to the seated passengers. To achieve this, individual components of the seat may be movable relative to a bulkhead (or partition), which separates a seating compartment from a loadspace of the vehicle. The bulkhead may itself be folded forward to increase the capacity of the loadspace.

The movement of the both the seat and the bulkhead may be driven by a system of motors which can be housed within the structure of the seat assembly. Consequently, the ability to reconfigure the seating in luxury SUVs is often compromised due to the increased weight and size of the seating assembly. In particular, some electric motors may not be able to provide sufficient torque to drive the components of the assembly between their folded and unfolded positions. It is therefore desirable to assist movement of the folding seat assembly in some way, and it is against this background that the present invention has been devised.

SUMMARY OF THE INVENTION

According to an aspect of the present invention there is provided a positioning system for a moveable vehicle seat assembly, the system comprising: an actuator controllable to move at least one component of the seat assembly between a first position and a second position, and a spring configured to bias the at least one component away from the second position.

Advantageously, the actuator and the spring work together to control the movement of the component. In particular, the assistance offered by the spring enables the output of the actuator to remain almost constant as the component moves between the unfolded and folded positions. By modulating the output of the actuator, the spring allows the actuator to run more quietly, thereby creating a more pleasant and relaxing environment for passengers seated in the vehicle. The modulation of the actuator output also prolongs its working life.

The spring may be configured to bias the at least one component towards the second position. In embodiments, the spring may be configured to bias the at least one component towards both the first position and the second position. In embodiments, the spring may be configured such that it biases the at least one component away from the first position under tension and it biases the at least one component away from the second position under compression.

The spring may be configured to cease biasing the at least one component at a third position, which may be arranged between the first position and the second position. The third position may define a neutral position wherein the spring is configured to apply no biasing force upon the at least component away from either the first or second positions. Alternatively, the first or second positions may be arranged between the third position and the other of the first and second positions.

The spring may be configured to disengage from the at least one component at the third position. The spring may be advantageously configured to selectively engage with the at least one component in order so that it only exerts torque during a predetermined portion of component’s movement between first and second positions

The spring may comprise a first end configured to engage a further component of the seat assembly, the at least one component being movable relative to the further component, and a second end configured to releasably engage the at least one component. The first end may provide a fixation point against which the spring may be biased.

The second end may comprise a flange, the flange being configured to come into engagement, and/or come out of engagement, with a protruding member of the at least one component. Advantageously, the spring may be configured to disengage the at least one component once it has discharged all of its potential energy. The spring will therefore provide no resistance to the subsequent motion of the at least one component.

The spring may be a clock spring. Advantageously, the clock spring is configurable to store a large potential energy, whilst being conveniently accommodated within a small volume at the pivot of the seating assembly, thereby reducing the packaging constraints of the positioning system.

The positioning system may comprise a second spring configured to bias the at least one component away from the first position. Advantageously, the first and second springs can work together to control the movement of the component between the first and second positions.

The second spring may be configured to cease biasing the at least one component at a fourth position, which may be between the first position and the second position.

The fourth position may be between the second position and the third position.

The fourth position substantially coincides with the third position such that the third and fourth positions, together, define a handover position in which the component may be transitioned between the first and second spring. A single handover position enables a smooth transition between the first and second spring and minimises the motion of the component for which the actuator is required to move the component unaided.

When in the handover position, the component may be arranged at a right angle to a seat cushion of the seat assembly. In other words, the component is substantially orthogonal to the seat cushion of the seat assembly when the component is arranged in the handover position. When in the handover position, the fist component may be in a substantially vertical position.

The second spring may comprise: a first end configured to engage a further component of the seat assembly, the at least one component being movable relative to the further component, and a second end configured to releasably engage the at least one component.

The second end may comprise a flange, the flange being configured to come into engagement, and/or come out of engagement, with a protruding member of the at least one component.

The first and second springs are configured to releasably engage with the same protruding member. Advantageously, the seating assembly maybe provided with a single protruding member by which it can be manoeuvred into position by both the first and second spring, thereby reducing the complexity of the mechanism.

The second spring may be a clock spring. A clock spring is able to conveniently store a large amount of potential energy whilst only taking up a small amount of space within the seating assembly.

The second spring may be arranged side-by-side with the first spring and wherein a torsional axis of the first spring may be aligned with a torsional axis of the second spring, thereby reducing the space taken up by the positioning system within the seat assembly. The torsional axis of the first spring may be defined as a rotational axis, likewise the torsional axis of the second may also be defined as a rotational axis of the second spring.

The coil-direction of the second spring opposes the coil-direction of the first spring such that first and second springs may be configured to apply opposing torques to the common protruding member.

The first spring may be configured to store more energy than the second spring such that it is configured to support the weight of the seat component when it is arranged in a folded position.

The actuator may comprise an electric motor. The output from the electric motor can be conveniently controlled by accurately controlling its current supply. Thus, the electric motor provides enhanced control over the movement of the seating assembly.

The electric motor may be configured to draw substantially constant power when moving the at least one component between the first position and the second position.

The first spring may be arranged adjacently to the second spring such that they may conveniently apply torque to a common protruding member. Furthermore, by arranging the springs adjacently, they may be configured to occupy a reduced footprint within the seating assembly.

The first component may comprise a bulkhead of the moveable seat assembly.

According to further aspect of the invention there is provided a moveable seat assembly comprising a first component, a second component and a positioning system according to any of the paragraphs above, wherein the actuator of the positioning system is controllable to move the first component between a first position and a second position relative to the second component.

The first component may be pivotally connected to the second component of the moveable seat assembly, and arranged to pivot about a pivot axis relative to the second component.

The spring may be located proximate to the pivot axis. The actuator may be located proximate to the pivot axis.

The first position may define a folded position of the first component and the second position may define an unfolded position of the first component.

The seat assembly may comprise a latch mechanism arranged to secure the first component in the unfolded position and the first spring is configured to eject the first component from the latch mechanism.

The seat assembly may comprise a second spring of the positioning system, the second spring being configured to bias the first component away from the folded position

The second spring may be configured to substantially balance the weight of the first component when the first component is arranged in the unfolded position. Thus, the amount of torque required by the actuator to move the seat component away from the folded position is reduced to a minimum, thereby allowing for a smaller, less heavy actuator to be used.

The first component may comprise a bulkhead of the moveable seat assembly. In alternative embodiments, the first component may comprise a seat-back of the moveable seat assembly.

According to yet further aspect of the invention there is provided a vehicle comprising a positioning system according to any one of previous paragraphs and/or a moveable seat assembly according to any of the previous paragraphs.

Within the scope of this application it is expressly intended that the various aspects, embodiments, examples and alternatives set out in the preceding paragraphs, in the claims and/or in the following description and drawings, and in particular the individual features thereof, may be taken independently or in any combination. That is, all embodiments and/or features of any embodiment can be combined in any way and/or combination, unless such features are incompatible. The applicant reserves the right to change any originally filed claim or file any new claim accordingly, including the right to amend any originally filed claim to depend from and/or incorporate any feature of any other claim although not originally claimed in that manner.

BRIEF DESCRIPTION OF THE DRAWINGS

One or more embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 is a top view of a luxury vehicle including a rear seating arrangement suitable for use in embodiments of the invention;

Figure 2 is a perspective view of the rear seating arrangement of Figure 1 arranged in an unfolded configuration;

Figure 3 corresponds to Figure 2, but shows the rear seating arrangement in a folded configuration;

Figure 4 is a perspective view of the rear seating arrangement of Figure 2, showing a positioning system in accordance with an embodiment of the invention;

Figure 5 is a perspective view of a spring of the positioning system shown in Figure 4;

Figure 6 is a perspective view of a gearing assembly of the positioning system shown in Figure 4;

Figures 7a to 7c show a component of the rear seating arrangement of Figure 2 through a series of stages of a folding sequence of the component; and,

Figures 8a to 8c correspond to Figures 7a to 7c, but show an unfolding sequence of the component.

DETAILED DESCRIPTION

Embodiments of the invention relate to apparatus for moving the components of a motorised seating assembly for a vehicle. Due to the weight of the components, the apparatus includes a spring to assist with the movement of the components between a folded and an unfolded position.

Before moving on to consider these embodiments in detail, to put the invention into context a seating arrangement to which such embodiments are applicable is described with reference to Figures 1 to 4.

Figure 1 shows in plan view, and in simplified form, a luxury vehicle 6 including a rear seating arrangement (or assembly) 1 and a positioning system 3 for controlling movement of components of the rear seating arrangement 1 according to embodiments of the invention. The rear seating arrangement 1 is disposed in a passenger compartment 2 of the vehicle 6, and a loadspace 4 is defined behind the seating arrangement 1. Figure 2 shows the rear portion of the passenger compartment 2 and the loadspace 4 in perspective view.

In the description that follows, the terms “forwards” and “backwards” are used to describe positions or locations of features relative to the vehicle 6. For example, the term “forwards” refers to locations or positions towards or nearer the front of the vehicle 6, and “backwards” refers to locations or positions towards or nearer the rear of the vehicle 6.

As seen most clearly in Figure 2, the passenger compartment 2 is separated from the loadspace 4 by a bulkhead 8 or partition that extends transversely between opposed sides of the vehicle 6. The loadspace 4 is commonly referred to as the “trunk” or “boot” or “cargo space” or “loading bay” of a vehicle. Luggage and other items are typically loaded into the loadspace 4 by opening a hinged hatch or door (not shown) at the rear of the vehicle 6 to provide access to the loadspace 4. The bulkhead 8 has a first surface 10 and a second surface 12. When the bulkhead 8 is arranged in an unfolded, or upright, configuration as shown in Figure 2, its first surface 10 and the second surface 12 define a forward facing and a backward facing surface of the bulkhead 8, respectively.

The rear portion of the passenger compartment 2 includes the seating arrangement 1, which is shown in a default configuration with the first surface 10 of the bulkhead 8 facing the passenger compartment 2 and the second surface 12 facing the loadspace 4 in Figure 2. Figures 1 to 3 will now be described together.

The seating arrangement 1 comprises a first seat 18, a second seat 16 and a separating portion defining a central seat 20, the central seat 20 being located between the first seat 18 and the second seat 16. With particular reference to Figures 2 and 3, each seat comprises a seat cushion 22, a squab (or seat-back) 24, a headrest 26 and a calf rest 27. The squabs 24 are located adjacent to the first surface 10 of the bulkhead 8. The central seat 20 comprises a central cushion 28 and a backrest that is pivotable to function as an armrest 30.

The seating arrangement 1 is referred to in the art as a 40-20-40 split: the first seat 18 comprises 40% of the seating of the seating arrangement 1, the central seat 20 comprises 20% of the seating of the seating arrangement 1 and the second seat 16 comprises 40% of the seating of the seating arrangement 1.

The seating arrangement 1 is shown in Figure 3 in a configuration in which a portion of the seat arrangement 1 is folded. The bulkhead 8 is asymmetrically divided into a first bulkhead portion 17a and a second bulkhead portion 19a. Accordingly, the seating arrangement 1 is divided into a first seat assembly 17 and a second seat assembly 19, as shown in Figure 2. The first seat assembly 17 comprises the first seat 18, the central seat 20 and armrest 30, and the first bulkhead portion 17a. The second seat assembly 19 comprises the second seat 16 and the second bulkhead portion 19a. In the example shown, the seating arrangement 1 has a 40-20-40 split meaning the first bulkhead portion 17a and the second bulkhead portion 19a is typically a 60-40 split. In this way, the first and second bulkhead portions 17a, 19a define major and minor portions of the bulkhead 8, respectively.

The first, second and central seats 18, 16, 20 are arranged so that the squabs 24 and armrest 30 may each fold forward about an axis 33 extending transversely across the vehicle 6 parallel to the plane of the bulkhead 8. The bulkhead 8 is also arranged to fold forward in cooperation with the seats 18, 16, 20.

With particular reference to Figure 2, it is noted that the squabs 24 of the first and second seats 16, 18 are separate to the bulkhead 8 of the seating arrangement 1, such that they can be moved independently from the bulkhead 8. The provision of a bulkhead 8 that can fold independently of the seats 18, 16, 20 increases the versatility of the seating arrangement 1. For example, this configuration allows the bulkhead to be used as a foundation for movement of the seat squabs 24, which is helpful in view of their relatively large size and weight resulting from the increased level of comfort that they are designed to provide. This arrangement also allows the bulkhead 8 to continue to separate the loadspace 4 from the passenger compartment 2 while the positions of the squabs 24 are adjusted. It will be appreciated that the rear seating arrangement 1 shown in Figures 1 to 3 is one example of a seating arrangement with which embodiments of the invention may be used. Alternative embodiments are configured for use with seating arrangements in which the bulkhead 8 and the squab 24 are fixedly mounted to form a single component of the seating arrangement 1, such that the bulkhead 8 and the squab 24 can only be moved as a single unit.

In the configuration of the seat arrangement 1 shown in Figure 3, the first seat 18 is in a folded configuration so that its squab 24 rests on its corresponding seat cushion 22. The first bulkhead portion 17a of the bulkhead 8, i.e. of the second seat assembly 17, is in an unfolded, default configuration. In this configuration the corresponding second bulkhead portion 19a is folded forward to lie on top of the squab 24, so that the first surface 10 of the second bulkhead portion 19a generally faces the floor of the passenger compartment 2 and the second surface 12 of the second portion of the bulkhead 8 generally faces the roof of the passenger compartment 2. The folded configuration of the first seat 18 allows a long load 32 to be carried by the vehicle 6 while allowing the second seat 16 and the central seat 20 to carry passengers.

Although not shown here, it will be appreciated by the skilled person that the seating arrangement 1 can be arranged such that both the first and second bulkhead portions 17a, 19a are arranged in a folded configuration, in which both of the squabs 24 and the armrest 30 are folded forward about the folding axis 33 so that each squab 24 and the armrest 30 engages its respective cushion 22, 28. In this fully-folded configuration, both the first and second portions of the bulkhead 8 are folded forward to lie on top of the squabs 24 and armrest 30 so that the first surface 10 of the bulkhead 8 generally faces the floor of the passenger compartment 2 and the second surface 12 generally faces the roof of the passenger compartment 2. The fully-folded configuration allows a larger load to be carried by the vehicle 6.

Figure 4 shows the seating arrangement 1 with the upholstery and cushioning removed to reveal the underlying support structure. The seating arrangement 1 is shown in Figure 4 in a configuration in which the squabs 24 of the first and second seating assemblies 17, 19 are spaced apart from the bulkhead 8. Each bulkhead portion 17a, 19a comprises an upper-support structure 38 and a bulkhead bracket 40, whereas the squabs 24 each comprise a squab-support structure 24a, which is connected pivotably to the bulkhead bracket 40 such that it can move relative to the bulkhead 8.

Each moveable seat assembly also comprises a support structure 34 which is configured to connect the assembly to the chassis of the vehicle 1. Specifically, the bulkhead bracket 40 of each assembly is connected to the support structure 34 by a pair of pivotable joints 54, which are located on opposite sides of each seating assembly. The pivotable joints 54 define a pivot axis 33 of each seating assembly about which the bulkhead 8 is pivoted.

With particular reference to the second seating assembly 19, a first pivotable joint 54a connects the bulkhead bracket 40 to a first arm 34a of the support structure 34 and a second pivotable joint 54b connects the bulkhead bracket 40 to a second arm 34b of the support structure 34 wherein the first arm 34a is located inwardly from the second arm 34b with respect to the interior cabin of the vehicle. In this way, the first and second pivotable joints 54 define, respectively, an inner and an outer pivotable joint 54a, 54b of the seating assembly. By virtue of this arrangement, the bulkhead 8 is pivotally connected to the support structure 34 of the second seating assembly 19, and arranged to pivot about the pivot axis 33 relative to the support structure 34 when in use.

The seating arrangement 1 further comprises a pair of catches 70 that are mounted at the sides of the bulkhead 8 towards the upper corners of the seating arrangement 1. The catches 70 are configured to engage with a latch mechanism (not shown), which is mounted to a vehicle cabin structure (not shown). The latching mechanism is operable to lock the bulkhead 8 in place in the unfolded position. This ensures that each bulkhead 8 is tightly retained when the seating arrangement 1 is in the unfolded position, providing a secure foundation for movement of other components of the seating arrangement including, for example, the squabs 24. It also acts to minimise vibration, and in turn noise, arising from movement of the bulkheads 8 whilst the vehicle 1 is in motion.

Each movable seating assembly comprises a positioning system 3 which is arranged to control the movements of the assembly between the unfolded (default) configuration and the folded configuration. Each positioning system 3 comprises an actuator 60 which is controllable to move a first component 39 of the seating assembly between a first and a second position relative to a second component 41 of the seating assembly. The positioning system 3 also comprises a spring arrangement 72 configured to work with the actuator 6 in order to move the first component 39 relative to the second component 41.

According to the embodiment described herein, the bulkhead 8 defines the movable first component 39 and the support structure 34 defines the second component 41. The first and second positions of the first component 39 correspond, respectively, with the folded and unfolded configurations of the seating assembly. In alternative embodiments, the actuator 60 may be configured to move other components of the seating assembly such as, for example, the squab 24. Equally, the first and second position of the movable component may correspond to any number of suitable arrangements of the seating assembly.

The actuator 60 and the spring arrangement 72 are located proximate to one of the pair of pivotable joints 54 of the seating assembly. In the exemplary arrangement shown in Figure 4, the actuator 60 of each seating assembly is located proximate to the inner pivotable joint 54a of each respective seating assembly. However, it would be clear to the skilled person that the actuator 60 may be arranged proximate to the outer pivotable joint 54b or at any other suitable location within each seating assembly.

Each actuator 60 is configured to exert respective forces on the bulkhead 8 to move it between the folded and unfolded positions. Specifically, the actuator 60 comprises a bulkhead motor which is mounted to an inwardly-facing surface 41 of the bulkhead bracket 40 of each seating assembly. Accordingly, the bulkhead motor moves with the bulkhead 8 as it transitions between the folded and unfolded positions. This also enables the bulkhead motor to be conveniently packaged within the frame of the seating assembly in order to reduce the packaging constraints of the positioning system 3.

With reference now to Figures 5 and 6, components of the positioning system 3 are arranged within the structure of each seating assembly as will be described in more detail below.

As seen most clearly in Figure 6, the bulkhead motor (which is hidden behind the bulkhead bracket 40 in this view) is connected to an axle 61 which protrudes through an access hole 63 in the bulkhead bracket 40 and connects with a drive gear 62 or sprocket. The drive gear 62 engages an intermediate gear 64, which is mounted to a transversely-facing surface 43 of the bulkhead bracket 40. The intermediate gear 64 further engages a driven gear 66, which forms a portion of the inner arm 34a of the seating assembly support structure 34 such that the driven gear remains stationary when the bulkhead 8 moves between the folded and unfolded positions. The central axis of the driven gear 66 is aligned with the pivoting axis 33 of the first seating assembly 19. The drive gear 62, the intermediate gear 64 and the drive gear 66 define a gearing assembly of the positioning system 3.

During operation of the actuator 60, the bulkhead motor drives the drive gear 62 which, in turn, drives the intermediate gear 64. As the driven gear 66 is fixed, on rotating the intermediate gear 64 traverses the path of the portion of the driven gear 66 with which the intermediate gear 64 engages, in turn moving the bulkhead 8. In this way, the driven gear 66 and the intermediate gear 64 define a rack-and-pinion type arrangement in which the driven gear 66 defines a curved ‘rack’ along which the intermediate gear 64 traverses when the bulkhead 8 is in motion. A guiding arrangement 67 ensures that the rack-and-pinion remain in alignment as the bulkhead 8 moves between its folded and unfolded positions.

The guiding arrangement 67 comprises a guiding channel 68 which is arranged in the body of the driven gear 66. The guiding channel 68 accommodates a guiding pin 69 of the guiding arrangement 67, which protrudes from the outwardly-facing surface 43 of the bulkhead bracket 40 and is configured to travel along the guiding channel 68 as the bulkhead 8 moves relative to the seating assembly support structure 34. The extreme ends of the channel 68, which define the limits of movement for the guiding pin 69, correspond to the unfolded and folded positions of the bulkhead 8. In this way, the guiding channel and pin 68, 69 are configured to conveniently prevent the intermediate gear 64 from being driven off either end of the driven gear 66 acting as a rack during operation of the positioning system 3. For example, in Figure 6 the arrangement of the positioning system 3 corresponds to the bulkhead 8 being in the unfolded position. In this configuration the intermediate gear 64 is positioned at the extreme end of the driven gear 66 when the guiding pin 69 is located at the extreme end of the guiding channel 68.

As seen most clearly in Figure 5, the spring arrangement 72 is arranged at the inner pivotable junction 54a of the first seating assembly 19. The spring arrangement 72 comprises a first clock spring 74 and a second clock spring 76. Each spring is configured to operate as a torsion spring, being formed from a strip of resilient material which is wound up along its length to form a coil. In embodiments, the clock springs are formed from stainless steel. However, it will be clear to the skilled person that the springs may be formed from any engineering material with suitable elastic properties.

Each clock spring comprises a first end 74a, 76a and a second end 74b, 76b. The first end 74a, 76a is configured to fixedly engage with the seating assembly structure 34 whilst the second end 74b, 76b is configured to releasably engage with the bulkhead

8. In this way, each clock spring is fixed to the seat assembly support structure 34 but can move freely with respect to the bulkhead 8. As will be explained in more detail below, the first spring 74 is configured to bias the bulkhead 8 away from the folded position whereas the second spring 76 is configured to bias the bulkhead 8 away from the unfolded position. Advantageously, the first and second springs 74, 76 are configured to assist the actuator 60 in moving the bulkhead 8 between the folded and unfolded positions. The second spring 76 is also configured to eject the catch 70 of the bulkhead 8 out from the latch mechanism when the catch 70 is released by the latch of the latch mechanism.

As is shown in Figure 5, the coil of the first spring 74 is wound in an opposite sense to the coil of the second spring 76.

The first end 74a, 76a of each clock spring 74, 76 is fixedly mounted to a spigot 35 of the seat assembly support structure 34. The first end 74a, 76a comprises a hollow sleeve 75, the sleeve 75 being axially aligned with the coil of the spring and shaped to match the shape of the spigot 35. The sleeve 75 is arranged to allow the springs 74, 76 to be slidably mounted onto a shaft of the spigot 35 so that the springs 74, 76 sit adjacent to, and in coaxial alignment with, each other. In this way, the second spring 76 is arranged side-by-side with the first spring 74 such that a rotational axis of the first spring 74 is aligned with a rotational axis of the second spring 76.

As is seen most clearly in Figure 6, the spigot 35 of the bulkhead 8 protrudes orthogonally from the transversely-facing surface of the inner arm 34a, so that the spigot 35 aligns with the pivoting axis 33 of the first seating assembly 19. The spigot 35 has a cross-section in the form of an oblong with rounded short sides. Accordingly, the shaft of the spigot 35 has two opposing rounded edges and two opposing flat edges. Due to this arrangement, the sleeve 75 of each spring 74, 76 is unable to rotate with respect to the spigot 35 when a torque is applied to the second end of the spring 74, 76.

The second end 74b, 76b of each clock spring 74, 76 comprises a curved flange 77 which is configured to come into and out of engagement with a protruding member 78 of bulkhead 8 as the bulkhead 8 is moved between the folded and unfolded positions. Each spring 74, 76 is configured to resist the force exerted upon it by the protruding member 78. Specifically, each flange 77 is configured so that the outer surface of each spring 74, 76 applies a resistive force against the protruding member 78 as the spring 74, 76 revolves around the spigot 35.

The flanges 77 are formed by folding the end of spring 74, 76 in the opposite direction to the direction in which the coil of the spring has been wound. Accordingly, it is the outer surface of each spring 74, 76 which releasably connects with the protruding member 78 of the bulkhead 8.

According to the embodiment described herein, the flange 74a of the first spring 74 is configured to engage with the protruding member 78 as the bulkhead 8 moves away from the folded position and towards the unfolded position, thereby loading the first spring 74. As the bulkhead 8 moves away from the unfolded position and towards the folded position the protruding member 78 engages with the flange 76a of the second spring 76, thus loading the second spring 76.

The flanges 77 are also configured to disengage the protruding member 78 at a common disengagement position, the disengagement position being disposed between the folded and unfolded positions of the bulkhead 8. When the protruding member is at the disengagement position, no force is applied to the bulkhead 8 by either clock spring 74, 76. Movement of the bulkhead 8 and, in turn, the protruding member, in either direction will start to load one of the springs 74, 76 and thus give rise to a force opposing that movement.

In this way, the flanges 77 are configured to effectively handover the protruding member 78 as the bulkhead 8 pivots between the unfolded and folded positions. Accordingly, the common disengagement position of the first and second clock springs 74, 76 defines a handover position of the spring arrangement 70. In embodiments, the first and second springs 74, 76 each have a different disengagement position such that there is no single handover position. Rather, the distance between the respective disengagement positions defines a ‘handover region’ in which control of the movement of the bulkhead 8 is transferred between the first and second springs 74, 76. In embodiments, the disengagement position of each spring may be separated so that neither spring is arranged to engage the bulkhead 8 as it moves across the handover region. In this configuration, the movement of the bulkhead 8 across the engagement region is controlled by the actuator 60 alone. In alternative embodiments, the springs 74, 76 may be configured to act, simultaneously, upon the bulkhead 8 as it travels across the handover region. For example, the first spring 74 may be configured such that it does not disengage with the bulkhead 8 until after the second spring 76 has begun its engagement. Accordingly, the springs 74, 76 are configured to at least partially work against each other as the bulkhead 8 moves between the respective disengagement positions.

For example, in Figure 5 the protruding member 78 is shown to be in engagement with the flange 74a of the first spring 74 when the bulkhead 8 is arranged in the unfolded position. In this configuration, the first spring 74 is being loaded in an anti-clockwise direction by the force which is exerted upon it by the protruding member 78. As the bulkhead 8 moves away from the unfolded position and towards the folded position, the flange 74a ceases to engage with the protruding member 78 at the point at which the first spring 74 is fully unloaded. Any further movement towards the folded position will commence loading of the second spring 76.

In this embodiment, the clock springs 74, 76 are also arranged so that the disengagement position corresponds to the bulkhead 8 being arranged in a substantially vertical position. That is, the bulkhead 8 is arranged in a substantially vertical position relative to the pivot axis 33, i.e. the centre of gravity of the bulkhead 8 is substantially vertically aligned with the pivot axis 33.

The positioning system 3 also comprises one or more switches (not shown) that control the bulkhead motors 60 that in turn effect movement of the respective components of the seating assemblies. Pressing a switch generates an electronic request signal that activates the positioning system 3 to perform a relevant movement through appropriate operation of the electric motors.

The switches are arranged in a door nearest to the respective seating assembly, which enables an occupant of the seat to input control requests to operate the relevant motor and thereby move the seat as desired. In embodiments the switches may be arranged on any suitable internal surface of the vehicle including, for example, an internal wall of the loadspace 4, which is accessible to an occupant upon opening a rear cargo door of the vehicle 6.

The motors of the positioning system 3 are in communication with a vehicle controller (not shown), which is configured to control the motors in dependence on input signals that are received from a human machine interface (HMI) of the vehicle. The HMI comprises a touch screen device which is mounted in a dashboard of the vehicle. In alternative embodiments the vehicle controller may be configured to receive input signals from a wirelessly connected device such as an electronic key or a personal computer.

To enable the reader to appreciate the advantages associated with the positioning system of this embodiment, operation of the positioning system 3 will be described in more detail below with reference to Figures 7a to 7c and 8a to 8c, and also Figure 9.

Figures 7a to 7c are side views of the second seating assembly 19 incorporating the bulkhead 8, the squab 24 and the head rest 26. Each of Figures 7a to 7c show the second seating assembly 19 in sequential stages of movement as the bulkhead 8 folds under the control of the positioning system 3.

The first stage of the folding operation shown in Figure 7a has the bulkhead 8 in the unfolded configuration. On activation of the positioning system 3 by an appropriate switch that controls folding of the seating assembly 19, the positioning system 3 takes appropriate action at the second stage by moving the bulkhead 8 towards the vertical position on its way to the folded position, as shown in Figure 7b. At the third stage shown in Figure 7c, the bulkhead 8 is pivoted further forwards beyond the vertical position, to adopt the folded position. As already noted, the sequence shown in Figures 7a to 7c is provided as an example only, and many variations are possible.

Figures 8a to 8c show the reverse operation, namely a retraction sequence in which the bulkhead 8 moves from a folded configuration to an unfolded configuration. Specifically, the first stage of the retraction operation shown in Figure 8a has the bulkhead 8 in the folded configuration in which it finished at the end of the folding operation of Figures 7a to 7c. Next, at the second stage the bulkhead 8 is moved towards the vertical position on its way to the unfolded position. At the third stage shown in Figure 8c, the bulkhead 8 is pivoted backwards to pass a vertical position and return to the unfolded position.

Figure 9 shows the results of a computer simulation which has been used to model the relative forces that are exerted by the positioning system 3 as the bulkhead 8 moves between the folded and unfolded positions. Figure 9 also shows how the torque that is exerted by the bulkhead 8 upon the components of the positioning system 3 changes as the bulkhead 8 moves between the folded and unfolded positions.

With reference to Figure 9, the dash-dot line labelled ‘Seat Torque’ corresponds to the torque exerted by the bulkhead 8 as it moves between the unfolded and folded positions. The maximum positive torque (+80 Nm) coincides with the bulkhead 8 being in the folded position, i.e. when it is positioned at +65 degrees from vertical. The maximum negative torque (-60 Nm) coincides with the bulkhead 8 being in the unfolded position, i.e. when it is arranged at -45 degrees to vertical. The change in the torque exerted by the bulkhead 8 is represented graphically in Figures 7a to 7c and 8a to 8c by shaded block arrows. In Figure 7b it can be seen that the bulkhead 8 is in the vertical position and so the weight of the seat assembly 19 exerts no net torque about the pivotable joint 54a. The size and position of the arrow represents the relative shift in the centre of gravity of the bulkhead 8 as it moves away from the vertical position.

Returning to Figure 9, the open dashed line labelled ‘Lowering Spring Torque’ corresponds to the combined output of the first and second springs 74, 76 when the bulkhead 8 is moving from the unfolded position to the folded position. The solid dashed line labelled ‘Raising Spring Torque’ corresponds to the combined output of the springs 74, 76 when the bulkhead 8 is moving from the folded position to the unfolded position. Although both line graphs represent the combined output of the first and second springs 74, 76 it is noted that the protruding member 78 is ‘handed over’ from one spring to the other as the bulkhead 8 pivots through the vertical position, and therefore the positive torque values represent the torque exerted by the first spring 74 and the negative torque values represent the torque exerted by the second spring 76. The offset between the ‘raising’ and ‘lowering’ line graphs represents energy losses associated with the loading and unloading of the springs 74, 76.

The torque exerted by the springs 74, 76 is represented graphically in Figures 7a to 7c and 8a to 8c by the dotted line arrows. It can be seen that the springs exert no torque on the bulkhead 8 at the ‘handover’ position. Conversely, the maximum torque exerted by the springs 74, 76 corresponds to the unfolded and folded positions wherein one of the springs is fully loaded. As can be seen in Figure 9, when the bulkhead 8 moves from the unfolded position to the folded position the first spring 74 initially acts against the torque of the bulkhead 8 to bring help bring the bulkhead 8 to the vertical position. The bulkhead 8 is then handed over to the second spring 76 which acts against the torque exerted by the bulkhead 8 to resist the lowering of the bulkhead 8 into the folded position. The reverse sequence is observed when the bulkhead 8 moves from the folded position to the unfolded position.

The bulkhead 8 is pivoted +65 degrees from vertical in a clockwise direction when it is arranged in the folded position. By contrast, the bulkhead 8 is pivoted -45 degrees from vertical in an anti-clockwise direction when assuming the unfolded position, as is shown in Figure 7a. A corresponding torque is applied to the respective clock spring in each position due to the magnitude of a component of the weight of the bulkhead 8, represented by the shaded block arrows in Figures 7a to 7c and 8a to 8c, which acts to turn the bulkhead 8. Consequently, the maximum torque applied to the first clock spring 74 is greater than the maximum torque that is applied to the second clock spring 76.

The coil of the first clock spring 74 comprises two complete turns whereas the coil of the second clock spring 76 comprises three complete turns. This allows the second clock spring 76 to store more energy than the first clock spring 74. Thus, the second clock spring 76 is able to counteract more effectively the torque of the bulkhead 8, which is greater when arranged in the folded position than in the unfolded position. Once arranged in the folded position, the bulkhead 8 cannot be urged out of the folded position by the torque of the second spring 76 alone. The mechanical resistance from the actuator 60 together with the gearing assembly act to inhibit the movement of the bulkhead 8 such that it remains in the folded position until the actuator 60 is configured to unfold the seat assembly. In alternative embodiments, the bulkhead may be actively held in place by the actuator 60, which is supplied with a holding current to prevent it from reversing.

Referring to Figure 9, it can be seen that the change in the torque exerted by the springs 74, 76 roughly mirrors the change in torque that is exerted upon the positioning system 3 by the bulkhead 8. In fact, the springs 74, 76 are configured to exert a greater torque than the bulkhead 8 such that the actuator 60 is required to exert a counter torque against the first and second spring 74, 76 in order for the bulkhead 8 to reach the unfolded and folded positions, respectively. In this way, the actuator 60 is configured to load each spring 74, 76 by driving the bulkhead 8 towards the unfolded and unfolded positions.

Returning again to Figure 9, the open solid line, labelled ‘Lowering Actuator Torque’, corresponds to the output of the actuator 60 when the bulkhead 8 is moving from the unfolded position to the folded position. The solid dashed line, labelled ‘Raising Actuator Torque’, corresponds to the output of the actuator 60 when the bulkhead 8 is moving from the folded position to the unfolded position. The change in the torque exerted by the actuator 60 is represented graphically in Figures 7a to 7c and 8a to 8c by the solid black line arrows. Referring specifically to Figures 7a to 7c, as the bulkhead 8 moves from the unfolded position to the folded position the actuator 60 initially assists the first spring 74 to help bring the bulkhead 8 to the vertical position. The initial spike in the actuator 60 output shown in Figure 9 corresponds to the lifting the bulkhead latch 70 from the catch mechanism. As the bulkhead 8 pivots through the handover position, the actuator 60 works with the weight of the bulkhead 8 to load the second spring 76 as it lowers the bulkhead 8 into the folded position.

The reverse sequence is observed when the bulkhead 8 moves from the folded position to the unfolded position. Specifically, as the bulkhead 8 moves from the folded position to the unfolded position the actuator 60 assists the second spring 76 to help bring the bulkhead 8 to the vertical position. As the bulkhead 8 pivots through the handover position the actuator 60 initially works with the weight of the bulkhead 8 to load the first spring 74 as it lowers the bulkhead 8 into the unfolded position. As the latch 70 of the bulkhead 8 engages with the catch mechanism the actuator 60 may apply a positive torque, acting with the first spring 74, to ensure that the latch mechanism has securely fastened the bulkhead 8 in position.

Referring once again to the graph of Figure 9, the hollow and solid dotted lines which represent the torque that is exerted, respectively, by the first and second springs 74, 76 are shown as passing through the same point on the x-axis. The crossover point represents a single handover position between the first and second springs 74, 76. The chained line, representing the seat torque, also crosses the x-axis at the same point on the graph. This represents the point where the bulkhead 8 passes through the vertical. In the vertical position, the weight of the bulkhead 8 is centred over the pivot such that it causes no positive or negative torque to be applied on the hinge assembly. Hence, the spring mechanism is configured such that its handover position coincides with the point at which the bulkhead 8 passes through the vertical position. In alternative embodiments, the spring mechanism may be arranged such that the handover position occurs when the bulkhead 8 is arranged substantially forward or rearward from the vertical position.

In summary, positioning of the bulkhead 8 between the unfolded and folded positions is achieved through operation of an actuator 60 in combination with a complementary spring arrangement 70. The actuator 60 and spring arrangement 70 work together to control the movement of the bulkhead 8. In particular, the assistance offered by the spring arrangement 70 enables the output of the actuator 60 to remain almost constant as the bulkhead 8 moves between the unfolded and folded positions. By modulating the output of the actuator 60, the springs 74, 76 allow the actuator 60 to run more quietly, thereby creating a more pleasant and relaxing environment for passengers seated in the vehicle cabin. The modulation of the actuator’s output also prolongs its working life.

According to embodiments of the present invention, the positioning system 3 also comprises a squab motor 25 for each moveable seating assembly, as is shown in Figure 4. Each squab motor 25 is configured to exert respective forces on each of the squabs 24 to rotate them about a squab rotation axis. In this way the squabs 24 are pivoted, relative to the bulkhead 8 of each seating assembly, such that they can be arranged in a number of seating configurations including a deployed position and a reclined position. In the deployed position an upper portion of the squab is pivoted 5 forward of the bulkhead 8 and in the reclined position the upper portion of the squab is pivoted back toward the bulkhead 8. In such embodiments, each positioning system 3 may also comprise a squab spring arrangement which is configured to allow modulation of the output required from the squab motors 24 to control the movement of the squabs 24. The squab motors 25 are identical to the bulkhead motors 60 in this 10 example although they may differ in other implementations, for example if differing levels of torque are required to fold the squabs 24 and the bulkhead 8.

Claims

1. A positioning system for a moveable vehicle seat assembly, the system comprising:

an actuator controllable to move at least one component of the seat assembly between a first position and a second position, and a spring configured to bias the at least one component away from the second position.

2. The positioning system of claim 1, wherein the spring is configured to cease biasing the at least one component at a third position.

3. The positioning system of claim 2, wherein the third position is between the first position and the second position.

4. The positioning system of claim 2 or claim 3, wherein the spring is configured to disengage from the at least one component at the third position.

5. The positioning system of claim 4, wherein the spring comprises a first end configured to engage a further component of the seat assembly, the at least one component being movable relative to the further component, and a second end configured to releasably engage the at least one component.

6. The positioning system of claim 5, wherein the second end comprises a flange, the flange being configured to come into engagement, and/or come out of engagement, with a protruding member of the at least one component.

7. The positioning system of any preceding claim, wherein the spring is a clock spring.

8. The positioning system of any preceding claim, comprising a second spring configured to bias the at least one component away from the first position.

9. The positioning system of claim 8, wherein the second spring is configured to cease biasing the at least one component at a fourth position.

10. The positioning system of claim 9, wherein the fourth position is between the first position and the second position.

11. The positioning system of claim 10, when dependent on claim 2, wherein the fourth position is between the second position and the third position.

12. The positioning system of claim 10, wherein the fourth position substantially coincides with the third position such that the third and fourth positions, together, define a handover position in which the component is transferred between the first and second springs.

13. The positioning system of claim 12, wherein, when in the handover position, the component is substantially orthogonal to a seat cushion of the seat assembly.

14. The positioning system of claim 12 or claim 13, wherein, when in the handover position, the component is in a substantially vertical position.

15. The positioning system of any one of claims 8 to 14, wherein the second spring comprises: a first end configured to engage a further component of the seat assembly, the at least one component being movable relative to the further component, and a second end configured to releasably engage the at least one component.

16. The positioning system of claim 15, wherein the second end comprises a flange, the flange being configured to come into engagement, and/or come out of engagement, with a protruding member of the at least one component.

17. The positioning system of claim 16, wherein the first and second springs are configured to releasably engage with the same protruding member.

18. The positioning system of any one of claims 8 to 17, wherein the second spring is a clock spring.

19. The positioning system of claim 18, wherein the first spring and the second spring are coiled in opposite senses.

20. The positioning system of claim 18 or claim 19, wherein the second spring is arranged side-by-side with the first spring and wherein a torsional axis of the first spring is aligned with a torsional axis of the second spring.

21. The positioning system of any one of claims 8 to 20, wherein the first spring is configured to store more energy than the second spring.

22. The positioning system of any preceding claim, wherein the actuator comprises an electric motor.

23. The positioning system of claim 22, wherein the electric motor is configured to draw substantially constant power when moving the at least one component between the first position and the second position.

24. The positioning system of any preceding claim, wherein the first spring is arranged adjacently to the second spring.

25. The positioning system of any preceding claim, wherein the first component comprises a bulkhead of the moveable seat assembly.

26. A moveable seat assembly comprising a first component, a second component and a positioning system according to any preceding claim, wherein the actuator is controllable to move the first component between a first position and a second position relative to the second component.

27. The moveable seat assembly of claim 26, wherein the first component is pivotally connected to the second component and is arranged to pivot about a pivot axis relative to the second component.

28. The moveable seat assembly of claim 27, wherein the spring is located proximate to the pivot axis.

29. The moveable seat assembly of claim 27 or claim 28, wherein the actuator is located proximate to the pivot axis.

30. The moveable seat assembly of any one of claims 26 to 29, wherein the first position defines a folded position of the first component and the second position defines an unfolded position of the first component.

31. The moveable seat assembly of claim 30, comprising a latch mechanism arranged to secure the first component in the unfolded position and the first spring is configured to eject the first component from the latch mechanism.

32. The moveable seat assembly of claim 30 or claim 31, comprising a second spring of the positioning system, the second spring being configured to bias the first component away from the folded position

33. The moveable seat assembly of claim 32, wherein the second spring is configured to substantially balance the weight of the first component when the first component is arranged in the unfolded position.

34. The moveable seat assembly of any one of claims 26 to 33, wherein the first component comprises a bulkhead of the moveable seat assembly.

35. The moveable seat assembly of any one of claims 26 to 34, wherein the first component comprises a squab of the moveable seat assembly.

36. A vehicle comprising a positioning system according to any one of claims 1 to 24 and/or a moveable seat assembly according to any one of claims 26 to 35.