GB2511091A

GB2511091A - Head restraint locking mechanism

Info

Publication number: GB2511091A
Application number: GB1303191.9A
Authority: GB
Inventors: Ryan Spackman; James Hosegood
Original assignee: Jaguar Land Rover Ltd
Current assignee: Jaguar Land Rover Ltd
Priority date: 2013-02-22
Filing date: 2013-02-22
Publication date: 2014-08-27
Anticipated expiration: 2033-02-22
Also published as: GB2511091B; GB201303191D0

Abstract

A head restraint stem locking mechanism has an escutcheon 10 having a bore receiving a stem 12, a locking member 16 with a catch portion 25 and an actuator 26. Locking member 16 is movable between an unlocked position, where stem 12 is axially movable, and a locked position, where catch portion 25 engages a notch 14 in stem 12. Locking member 16 is resiliently biased towards the locked position. Actuator 26 operates to cause catch portion 25 to move substantially perpendicularly to stem 12. Actuator 26 may move parallel to stem 12 and may be an annular cap-shaped button surrounding stem 12; alternatively actuator 26 may be a knob rotatable about stem 12. A guide prong 36, 38 may extend from actuator 26 through a recess 18, 20 in escutcheon 10 to move a lever 22 engaging locking member 16. The mechanism reduces play and is operable without tools.

Description

Head Restraint Locking Mechanism

TECHNICAL FIELD

This invention relates to a head restraint locking mechanism and in particular, but not exclusively, to a head restraint locking mechanism for use in an automotive vehicle.

Aspects of the invention relate to a locking mechanism and head restraint arrangement, to a seat with a locking mechanism for a head restraint mechanism, to a seat and head restraint arrangement and to a method of removing a head restraint from a seat and head restraint arrangement.

BACKGROUND

Many road vehicles are supplied with head restraints installed at the top of the seats, primarily in order to protect the occupant of the seat from withstanding a head or neck injury in the event of the vehicle coming to a sudden stop, for example in a collision. In addition to this, the head restraint may provide a level of additional comfort for the occupant.

A head restraint generally incorporates a padded element to provide a cushioning effect! which is mounted on a pair of stems. The stems are received in respective holes at the top of the vehicle seat. In order to meet the needs of a range of occupants of varying height, the head restraint is generally adjustable, such that the padded element may be positioned at varying heights relative to the seat to accommodate different users. Previously, this may have been achieved by including a number of notches on one or more of the stems, with a latching mechanism provided in the respective hole in which that stem is received, so that the user may move the head restraint up or down as desired, and lock it in place by latching on an appropriate notch using a button to actuate the latching mechanism. To remove the head restraint from the seat, the latching mechanism is opened to allow the stems to be fully removed from the holes. A disadvantage to this arrangement is that, as the padded element is moved higher, a progressively shorter length of the stem is held within the seat. At the higher end of the range of adjustment, this may lead to a level of play associated with the padded element which is unacceptable.

Partly because of these problems, there has been a move towards the use of head restraints which are arranged with stems which are fixed in position once installed in the vehicle seat, such that the length of the internal portion of the stem is consistent and sufficient to provide the required level of protection. In these arrangements, height adjustment is achieved by moving the padded element up or down relative to the stem, rather than by moving the stem itself up and down.

However, it is often desirable for the head restraint to be removable, for example so that child car seats may be fitted and tested more easily. As the stems are no longer free to move in the current designs, an additional release mechanism has to be included to enable the releasing of the stems. There are various legal requirements which apply to these release mechanisms which govern their design, primarily in that it should not be possible to release the head restraint accidentally. Additionally, the release mechanism must not be so easy to use that a child could remove the head restraint.

Current head restraint release mechanisms are generally offered in one of two forms.

Both forms include a locking mechanism embedded within the vehicle seat to hold the stem in place. The locking mechanism is provided with a button on the side which releases the stem when pressed. However, in both cases, the button is also embedded within the seat, and therefore generally inaccessible.

In the first form of locking mechanism which is known in the art, the seat is provided with a removable rear panel, which provides access to the release button when removed. This arrangement has the disadvantage that a level of disassembly is required in order to remove the head restraint, which is time consuming and may be inconvenient. In the second form of locking mechanism known in the art, a small hole or slot is made in the seat to provide access to the button, although the hole is sized such that access can only be gained through the use of a tool. The requirement for a tool to release the head restraint is a clear disadvantage.

Against this background, it is an aim of the invention to provide a release mechanism which meets current requirements, but which provides an improved release method for the head restraint compared with currently implemented designs.

SUMMARY OF THE INVENTION

According to a first aspect of the present invention there is provided a locking mechanism for releasably locking a head restraint comprising a stem to a seat, the locking mechanism comprising: an escutcheon defining a bore, the bore having a bore axis and arranged to be dimensioned to receive the stem of the head restraint; a resiliently biased locking member comprising a stem engagement portion, the locking member arranged to be moveable between an unlocked position in which the stem can move within the bore and a locked position in which the stem engagement portion locates within a notch in the stem of the head restraint; an actuation member arranged to move the locking member from the locked position to the unlocked position; wherein (i) the resiliently biased locking member is biased towards the locked position; (ii) the stem engagement portion is arranged to move in a first direction that is substantially perpendicular to the bore axis when the locking member moves between the locked and unlocked positions; and (Ui) the actuation member is arranged to move in a second direction.

The ability to move the engagement portion in a first direction and the actuation member in a second direction means that the location of the actuation means is not restricted by the position and movement of the engagement means. This allows for the positioning of the actuation member in a location which is convenient for a user, for example at the top of the seat. When positioned on the top of the seat, the actuation means can advantageously be accessed from either side of the seat.

Furthermore, locating the actuation means on the top of the seat helps to ensure that it is not activated accidentally by the user.

The actuation member may be operatively connected to the locking member, or the actuation member may be located above the locking member and supported by, for example, the foam of the seat. In the latter arrangement, the actuation means can be made to operatively connect to the locking member by compressing the foam.

The second direction may be substantially parallel to the bore axis.

Advantageously, the actuation member may be arranged to move the locking member by means of a lever arrangement, lever arrangement being arranged to translate the substantially parallel motion of actuation member relative to the bore axis into motion substantially perpendicular to the bore axis.

The locking member may comprise a first part that is substantially parallel to the bore axis and a second part that is substantially perpendicular to the bore axis, the stem engagement portion being located on the second part and the lever arrangement being operably connected to the first part.

The lever arrangement may be arranged to pivot about a pivot point.

The actuation member may comprise a prong extending therefrom in a direction substantially parallel to the bore axis, said prong being arranged to engage with the lever arrangement.

The actuation member may comprise at least one guide prong which is received by a respective recess in the escutcheon, wherein the guide prong is arranged to ensure correct alignment of the actuation means with respect to the escutcheon.

The actuation member may be operably connected to the locking member by means of a pin member.

The second direction comprises rotation of the actuation member about the bore axis.

A surface of the actuation member may be arranged to move the locking member, said surface having a profile which varies in a direction parallel to the bore axis as the actuation member rotates relative to the locking member.

The actuation member may comprise a through hole arranged to be dimensioned to allow the stem to pass therethiough.

According to a second aspect of the present invention there is provided a locking mechanism and head restraint arrangement comprising: a locking mechanism according to the first aspect of the present invention; and a head restraint comprising a stem.

The head restraint may comprise two stems each of which engage with a locking mechanism according to the fiist aspect.

The head restraint may further comprise a padded element thereon.

According to a third aspect of the present invention there is provided seat with a locking mechanism for a head restraint, the seat comprising: a seat back; a locking mechanism according to the first aspect of the present invention secured within the seat back; wherein the seat back comprises an opening at the top of the seat back, the opening aligning with the bore of the locking mechanism.

The actuating member may be located in the vicinity of the opening at the top of the seat back.

The seat may comprise a body at least partly formed from a foam-like material and a seat cover material wherein the actuating member is formed from two pieces, one piece of which is located between the foam-like material and the seat material and the second of which is located on top of the seat material and above the first piece.

According to a fourth aspect of the present invention there is provided a seat and head restraint arrangement comprising: a seat according to the third aspect of the present invention; and a head restraint comprising a stem; wherein the stem is located within the bore of the locking mechanism.

According to a fifth aspect of the present invention there is provided a method of removing a head restraint from a seat and head restraint arrangement wherein the seat comprises a locking mechanism for releasably locking a head restraint comprising a stem to the seat, the locking mechanism comprising: an escutcheon defining a bore, the bore having a bore axis and arranged to be dimensioned to receive the stem of the head restraint; a resiliently biased locking member comprising a stem engagement portion, the locking member arranged to be moveable between an unlocked position in which the stem can move within the bore and a locked position in which the stem engagement portion locates within a notch in the stem of the head restraint; an actuation member arranged to move the locking member from the locked position to the unlocked position wherein (i) the resiliently biased locking member is biased towards the locked position; (ii) the stem engagement portion is arranged to move in a first direction that is substantially perpendicular to the bore axis when the locking member moves between the locked and unlocked positions; and (iU) the actuation member is arranged to move in a second direction, the method comprising: moving the actuation member in the second direction in order move the locking member to the unlocked position; and removing the stem from the bore.

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.

Features described in connection with one embodiment are applicable to all embodiments, unless such features are incompatible.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which like components are assigned like numerals, and in which:-Figure 1 is a schematic drawing showing a cross section of a head restraint release mechanism according to one embodiment of the invention, in which a cap is provided with an activation peg; Figures 2a) and b) are perspective views of a head restraint release mechanism according to an alternative embodiment of the invention, as seen from thefront; Figures 3a) and b) are perspective views of the head restraint release mechanism in Figure 2 with a head restraint inserted, as seen from the front; Figures 4a) and b) are side views of the head restraint release mechanism in Figure 2 with a head restraint inserted; and Figure 5 a side view showing the head restraint release mechanism in Figure 2 when assembled into a vehicle seat.

DETAILED DESCRIPTION

Figure 1 illustrates a head restraint release mechanism according to an embodiment of the present invention. The release mechanism 5 includes a housing in the form of an escutcheon 10 which is generally tubular and defines a bore 9 having a central axis 11, with an enlarged region at one end. A stem 12 of a head restraint is received by the escutcheon 10. The stem 12 is provided with a notch 14 which is arranged to be locked within the bore 9 by a resiliently biased locking member in the form of a spring 16 which engages the notch 14, defining a locked position for the spring 16 as shown in Figure 1. The enlarged portion of the escutcheon 10 is provided with a first recess 18 and a second recess 20. A lever 22 is received at one end in the second recess 20, where a tip of the lever 22 is pivotably connected to the escutcheon 10.

The other end of the lever 22 engages a dog-leg shaped section 24 of the spring 16.

The spring 16 of this embodiment consists of a wire which is shaped to comprise an engagement portion 25, and the dog leg section 24. The engagement portion 25 sits inside the escutcheon 10 and surrounds the stem 12, with a portion of the engagement portion 25 engaging with the notch 14 of the stem 12 when in the locked position. The dog leg section 24 extends away almost perpendicular to the engagement portion 25. The spring 16 is supported at the bottom end of the dog leg section 24, in a manner which biases the dog leg section 24 towards an upright position, and hence biases the engagement portion 25 into the locked position to engage with the notch 14.

The release mechanism 5 is arranged so that the notch 14 is positioned as low as possible in the escutcheon 10 when it engages with the spring 16. This ensures that the load on the stem 12 is minimised, in use. It will be appreciated that the engagement position of the notch 14 is determined by the position of the spring 16.

The position of the spring 16 is in turn substantially determined by the form of the lever 22; a longer lever 22 allows the spring 16 to be positioned further down the escutcheon 10 to engage with the lever 22.

An actuation member in the form of a cap 26 is positioned coaxially with the central axis 11, and the cap 26 is located above the escutcheon 10. The cap 26 is formed with an upper portion 28 and a lower portion 30, which sit above and below a leather outer layer 32 of the vehicle seat 33 (not shown in Figure 1, shown in Figure 5). The upper and lower portions 28, 30 of the cap 26 clamp together to attach the cap 26 to the leather outer layer 32 of the seat 33. The cap 26 is formed with an integral activation peg 34, which may be provided with a plurality of prongs arranged in a circular pattern extending from a lower surface of the activation peg 34. A first prong 36 and a second prong 38 are visible in Figure 1. The first and second prongs 36, 38 are received in respective recesses 18, 20 in the escutcheon 10. The remaining prongs which are not shown are also received in respective recesses, which are also not shown. The recesses 18, 20 are funnel shaped so as to guide the prongs 36, 38 into the recesses 18, 20 when the cap 26 and activation peg 34 are pressed downwards to meet the escutcheon 10. In this way, any misalignment of the cap 26 with respect to the escutcheon 10 is compensated for. In alternative arrangements the peg may carry fewer prongs than recesses in the escutcheon.

The cap 26 and integral activation peg 34 are supported in an initial position by a layer of foam 40, which is a standard component of the vehicle seat 33. The cap 26 and integral activation peg 34 are formed with a central hole (not shown) which is positioned coaxially with the central axis 11. The central hole is arranged to receive the stem 12 of the head restraint to allow the stem to be inserted into and removed from the escutcheon 10, and the seat 33 itself. The central hole, cap 26 and escutcheon are all coaxial around the central axis 11.

In this embodiment, a release mechanism 5 is provided for each stem 12 of the head restraint, the head restraint having at least two stems 12. Therefore, a vehicle seat 33 has at least two release mechanisms 8 installed. To remove the head restraint, all stems 12 must be released simultaneously. In this way, the arrangement provides a level of protection against the accidental removal of the head restraint.

An initial position (corresponding to when the spring is in the locked position) for the release mechanism 5 is defined when no pressure is applied to the cap 26, and therefore the foam layer 40 is in its normal, uncompressed state, and the cap 26 is at its highest point. When the mechanism 5 is in this initial position, the activation pin sits above the escutcheon, with the first prong 36 clear of the escutcheon 10, in alignment with the first recess 18. In an alternative embodiment, when in the initial position, the first prong 36 sits at the top of the first recess 18 of the escutcheon 10, in contact with the tip of the lever 22.

At this point, the first prong 36 does not apply any force to the lever 22, and therefore the lever 22 in turn does not apply an actuating force to the spring 16. The spring 16 is arranged to be biased towards the lever 22, such that the spring 22 clips into the notch 14 of the stem 12 when allowed to. The second prong 38 (and the remaining prongs which are not shown) is received at the top of the second recess (the other prongs being received by their respective recesses), and acts to locate the activation peg 34 and ensure correct orientation.

To insert a head restraint, the user must push the stern 12 into the central hole of the cap 26, and downwards along the central axis 11 through the activation peg 34 and into the bore 9 in the escutcheon 10. At this point, the spring 16 is in the locked position, and therefore obstructs the stem 12. Therefore, the end of the stem 12 is formed with a taper (not shown) which guides the spring 16 out of the path of stem 12 as it moves downwards. As the spring 16 is moved away from the central axis 11, an unlocked position for the spring 16 is defined. When the notch 14 draws level with the spring 16, the biasing action of the spring 16 causes the spring 16 to return to the locked position and clip into the notch 14. thereby locking the stem 12 in position.

The inner diameter of the escutcheon 10 is sized accordingly to allow enough room for the spring 16 to move out of the way of the stem 12 as it moves downwards past the spring 16 when in the unlocked position. In an alternative embodiment, the inner surface of the escutcheon is provided with a groove or a series of apertures to allow room for the spring 16 to move into the unlocked position. This alternative embodiment accords the release mechanism the advantage that the inner diameter of the escutcheon 10 may be more closely matched to the diameter of the stem 12, ensuring a tighter fit. This substantially eliminates play of the stem 12 in the release mechanism 5, which results in a head restraint which is more robust and which does not wobble.

This procedure occurs for each stem 12 of the head restraint as the stems 12 are inserted into their respective release mechanisms 5. Thus the head restraint is installed and can be used. Height adjustment for the head restraint is provided for separately to the release mechanism 5, by allowing the padded element of the head restraint to move up and down relative to the stem 12, while the stem 12 remains stationary, as described previously. Therefore the release mechanism 5 provides a semi-permanent lock to hold the stem 12 of the head restraint in place.

In order to release the stem 12, a user pushes the cap 26 downwards in the direction generally indicated by arrows 42 and 44, in a direction substantially parallel to axis 11. As the cap 26 and integral activation peg 34 move downwards, the contact point between the first prong 36 and the lever 22 moves downwards accordingly. This causes the lever 22 to pivot about its tip, meaning that the lower end of the lever 22 moves towards the central axis 11 and presses against the dog leg 24 section of the spring 16. This action moves the spring 16 horizontally towards the unlocked position, until the engagement portion 25 is moved completely outside the notch 14, whereupon the stem 12 is unlocked and may be released and removed. If the same action is performed simultaneously on the other release mechanisms 8 which are provided in the vehicle seat 33 to release all stems 12, the head restraint may be removed by pulling it upwards to move the stems 12 out of the respective escutcheons 10 and then out of the respective caps 26.

When the cap 26 is pushed downwards by the user, this compresses the foam layer 40. Therefore, when the user removes the applied force from the cap 26, the cap 26 is returned to the initial position as the foam expands to its normal state. This releases the lever 22, which in turn allows the spring 16 to return to its locked position in the notch 14.

A second embodiment of the invention is now described with reference to Figures 2 to 5. This embodiment differs from the embodiment described above with reference to Figure 1 in that the cap 26 is not formed with an integral activation peg 34. Instead, the escutcheon 10 is provided with an activation pin 46 with which the cap 26 engages when pressed down by the user. The activation pin 46 performs the same function as the first prong 36 of the embodiment shown in Figure 1, in that the activation pin 46 is in contact with the lever 22, and acts to press the lever 22 towards the stem 12 when the cap 26 is pushed down by the user. In this way the spring 16 is pushed out of the notch 14 of the stem 12, therefore moving the spring 16 from the locked position to the unlocked position and releasing the stem 12.

Figure 2 shows a perspective view of the release mechanism 5 prior to a stem 12 being inserted. In this illustration, the surrounding components of the vehicle seat 33 are not shown, so the cap 26 appears to float. It should be appreciated that the cap 26 is supported by the foam layer 40 of the vehicle seat 33 in the same way as in the embodiment of Figure 1. This is illustrated more clearly in Figure 5, which shows the release mechanism 5 in situ in the vehicle seat 33.

Figure 2 shows clearly the lever 22 of this embodiment, which is in the form of a cross. The lever 22 is constituted by a substantially vertical section 48, which engages with the activation pin 46, and a horizontal section 50, which engages with the spring 16. The vertical section 48 provides a surface for the activation pin 46 to slide up and down in order to effect the actuating movement of the lever 22. The horizontal section 50 ensures that the actuating force from the lever 22 is applied to the spring 16 over a wide area. This ensures even and balanced movement of the spring 16 from the locked position to the unlocked position, so that it is moved cleanly out ot the notch 14 when the activation pin 46 is pressed down by the user. If the lever 22 did not include the horizontal section 50, the actuating force would be applied to a single point of the spring 16 only, at the point where the spring 16 makes contact with the vertical section 48. This may cause the spring 16 to twist and move unevenly, especially if the contact point was not precisely central, or if the spring 16 was not sufficiently symmetrical, therefore compromising the performance of the release mechanism 5.

The outer surface of the escutcheon 10 in Figure 2 is provided with a number of small extrusions 52. These extrusions 52 are used to secure the escutcheon 10 to a bracket 54 in the vehicle seat 33, which is shown in Figure 5.

Figures 3 and 4 show the release mechanism 5 with a stem 12 inserted, from two different perspectives. These figures illustrate that the stem 12 can guide the movement of the cap 26 when the user presses the cap 26 down towards the escutcheon 10. This ensures that the cap 26 successfully engages with the activation pin 46.

Figure 4 is a side view of the release mechanism 5, in which the notch 14 of the stem may be seen. This figure also illustrates an aperture 56 which is provided in the escutcheon 10 of this embodiment. When the spring 16 is pushed forward to release the stem 12, the spring 16 moves into this aperture 56. Providing the aperture 56 allows the inner diameter of the escutcheon 10 to be more closely matched to the diameter of the stem 12, which ensures a tighter fit. This therefore substantially eliminates play of the stem 12 within the release mechanism 5, as described previously.

Figure 5 illustrates how the release mechanism 5 is located within the vehicle seat 33 when installed. As noted above, the release mechanism 5 is held in place by a bracket 54 which clamps around the escutcheon 10 and engages with the outer extrusions 52. The bracket 54 is attached to the main body 58 of the seat 33. In this embodiment, the release mechanism is installed such that its central axis 11 is parallel to the rear of the seat 33. The seat 33 is generally reclined in order to provide improved comfort for the occupant, therefore the release mechanism 5 is not vertical.

In order to provide useful height adjustment within the limitations of the vehicle interior, it is necessary for the padded element to move up and down in a substantially vertical plane. Therefore, the stem 12 is formed with a bend, such that an exposed portion 60 of the stem 12 which is outside of the vehicle seat 33 is substantially vertical, whereas an interior portion 62 of the stem 12 which is contained by the release mechanism 5 is parallel to the central axis 11 of the release mechanism 5.

In the above described embodiments of the head restraint release mechanism 5, the S releasing action is effected by the user pushing the cap 26 downwards in generally linear movement. In an alternative embodiment, the release mechanism 5 is arranged such that the user twists the cap 26 in order to release the stem 12. In this embodiment, the cap 26 may be formed with a sculpted lower surface which engages with an activation pin 46, such that the thickness of the lower section of the cap 26, namely the section of the cap which is positioned below the leather layer 32 of the seat 33, varies around its circumference. Therefore, an initial position in which no pressure is applied to the locking spring 16 via the cap 26 is defined when the thinnest section of the cap is directly above the activation pin 46. When the cap 26 is twisted about the central axis 11, the profile of the lower surface of the cap 26 moves progressively downwards towards the activation pin 46. This occurs as a result of the thickness of the cap below the leather layer 32 increasing. This leads to the cap 26 progressively moving the activation pin 46 downwards towards the lever 22, therefore releasing the stem 12.

In a further embodiment, the dog leg portion 24 of the spring 16 is arranged to extend upwards to engage directly with the cap 26. In this embodiment, the lever 22, activation peg 34 and the activation pin 46 are not required. When the cap 26 is pressed down or twisted, this forces the dog leg portion 24 of the spring 16 downwards. The escutcheon 10 is arranged to constrain the movement of the spring to a path which ensures that as the dog leg portion 24 of the spring moves downwards, the engagement portion 25 moves generally horizontally towards the unlocked position such that it exits the notch 14 and releases the stem 12.

Claims

CLAIMS1. A locking mechanism for releasably locking a head restraint comprising a stem to a seat, the locking mechanism comprising: an escutcheon defining a bore, the bore having a bore axis and arranged to be dimensioned to receive the stem of the head restraint; a resiliently biased locking member comprising a stem engagement portion, the locking member arranged to be moveable between an unlocked position in which the stem can move within the bore and a locked position in which the stem engagement portion locates within a notch in the stem of the head restraint; an actuation member arranged to move the locking member from the locked position to the unlocked position; wherein (i) the resiliently biased locking member is biased towards the locked position; (ii) the stem engagement portion is arranged to move in a first direction that is substantially perpendicular to the bore axis when the locking member moves between the locked and unlocked positions; and (iii) the actuation member is arranged to move in a second direction.
2. A locking mechanism as claimed in claim 1, wherein the second direction is substantially parallel to the bore axis.
3. A locking mechanism as claimed in claim 2, wherein the actuation member is operably connected to the locking member by means of a lever arrangement, lever arrangement being arranged to translate the substantially parallel motion of actuation member relative to the bore axis into motion perpendicular to the bore axis.
4. A locking mechanism as claimed in claim 3, wherein the locking member comprises a first part that is substantially parallel to the bore axis and a second part that is substantially perpendicular to the bore axis, the stem engagement portion being located on the second part and the lever arrangement being operably connected to the first part.
5. A locking mechanism as claimed in claim 3 or claim 4, wherein the lever arrangement is arranged to pivot about a pivot point.
6. A locking mechanism as claimed in any one of claims 3 to 5, wherein the actuation member comprises a prong extending therefrom in a direction substantially parallel to the bore axis, said prong being arranged to engage with the lever arrangement.
7. A locking mechanism as claimed in claim 6, wherein the actuation member comprises at least one guide prong which is received by a respective recess in the escutcheon, wherein the guide prong is arranged to ensure correct alignment of the actuation means with respect to the escutcheon.
8. A locking mechanism as claimed in any one of claims 2 to 5, wherein the actuation member is operably connected to the locking member by means of a pin member.
9. A locking mechanism as claimed in claim 1, wherein the second direction comprises rotation of the actuation member about the bore axis.
10. A locking mechanism as claimed in claim 9, wherein a surface of the actuation member is operably connected to the locking member, said surface having a profile which varies in a direction parallel to the bore axis as the actuation member rotates relative to the locking member.
11. A locking mechanism as claimed in any preceding claim, wherein the actuation member comprises a through hole arranged to be dimensioned to allow the stem to pass therethrough.
12. A locking mechanism and head restraint arrangement comprising: a locking mechanism as claimed in any one of claims 1 to 11; and a head restraint comprising a stem.
13. A locking mechanism and head restraint arrangement as claimed in claim 11, wherein the head restraint comprises two stems each of which engage with a locking mechanism as claimed in any one of claims 1 to 11.
14. A locking mechanism and head restraint arrangement as claimed in claim 12 or claim 13, wherein the head restraint further comprises a pillow member thereon.
15. A seat with a locking mechanism for a head restraint, the seat comprising: a seat back; a locking mechanism as claimed in any one of claims 1 to 11 secured within the seat back; wherein the seat back comprises an opening at the top of the seat back, the opening aligning with the bore of the locking mechanism.
16. A seat as claimed in claim 15, wherein the actuating member is located in the vicinity of the opening at the top of the seat back.
17. A seat as claimed in claim 15 or claim 16, wherein the seat comprises a body at least partly formed from a foam-like material and a seat cover material wherein the actuating member is formed from two pieces, one piece of which is located between the foam-like material and the seat material and the second of which is located on top of the seat material and above the first piece.
18. A seat and head restraint arrangement comprising: a seat as claimed in any one of claims 15 to 17; and a head restraint comprising a stem; wherein the stem is located within the bore of the locking mechanism.
19. A method of removing a head restraint from a seat and head restraint arrangement wherein the seat comprises a locking mechanism for releasably S locking a head restraint comprising a stem to the seat, the locking mechanism comprising: an escutcheon defining a bore, the bore having a bore axis and arranged to be dimensioned to receive the stem of the head restraint; a resiliently biased locking member comprising a stem engagement portion, the locking member arranged to be moveable between an unlocked position in which the stem can move within the bore and a locked position in which the stem engagement portion locates within a notch in the stem of the head restraint; an actuation member arranged to move the locking member from the locked position to the unlocked position wherein (i) the resiliently biased locking member is biased towards the locked position; (ii) the stem engagement portion is arranged to move in a first direction that is substantially perpendicular to the bore axis when the locking member moves between the locked and unlocked positions; and (iH) the actuation member is arranged to move in a second direction, the method comprising: moving the actuation member in the second direction in order move the locking member to the unlocked position; and removing the stem from the bore.