AU2012224469A1 - Child Safety Restraint - Google Patents

Abstract

The present invention provides a child safety seat for a vehicle comprising: a seat portion; a backrest portion mounted with respect to the seat portion; a headrest mounted to the backrest portion so as to be movable with respect to the backrest portion in a vertical direction; an activation mechanism mounted on the headrest, the activation mechanism being configured such that when the activation mechanism is in a first state, movement of the headrest with respect to the backrest portion is prevented and when the activation mechanism is in a second state, movement of the headrest with respect to the backrest portion is permitted; wherein, the activation mechanism is positioned on said headrest so as to be accessed by a user with one hand to facilitate adjustment of the vertical position of the headrest with respect to the backrest portion.

Description

Child Safety Restraint FIELD OF INVENTION The present invention generally relates to a child restraint for use in a vehicle, 5 and in particular, to child safety seat having an integral headrest for supporting and/or protecting a head region of a child seated therein. BACKGROUND ART Child restraints have been developed to improve the safety of children travelling in vehicles. A variety of different types of child restraints have been developed 10 for this purpose, with most child restraints consisting of a seat or chair which is supported on a rear seat of a vehicle, for receiving the child therein. There exist a variety of types of child safety seats that are approved for use with children of a variety of ages and/or sizes. Type A seats typically refer to rear facing seats or capsules suitable for accommodating babies/infants up to around 6 15 months of age and/or 70cm in length and up 12kg. Type B seats typically refer to forward facing seats used to accommodate toddlers and young children from approximately 6 months to 4 years, or from 8 - 18kg. Type E seats typically refer to booster seats and booster cushions used to accommodate children between 4 - 8 years old, or approximately from 14 - 32kg, and which are 20 typically used in combination with the vehicle seat belt. Some seats may be a combination type A/B or B/E to accommodate a child as they child grows thereby avoiding the need to purchase, or otherwise source, a variety of different seats to accommodate a growing child. For Type A, Type B, Type A/B and Type B/E child safety seats, it has been 25 known to employ a headrest within the seat shell that is attached to an inner surface of the backrest portion thereof, to provide support to the child's head and neck region when the child is seated therein. The headrest is typically formed to comprise a curved body having a pair of wing portions and extend along opposing sides of the child's head region so as to provide a degree of protection 30 to the child's head region in the event of a side impact, as well as to limit any unwanted head movement of the child in the event of an accident. The headrest portion is typically covered with a cushion material or similar covering to provide a degree of comfort to the child and aesthetic appeal to the seat.

As many available child safety seats are typically designed to accommodate a child as they grow, in child safety seats having a headrest portion, it is typically necessary to provide a means for adjusting the position of the headrest along the surface of backrest portion of the seat as the child grows. In some child safety 5 seats, the means for adjusting the position of the headrest along the surface of the backrest is often difficult to use and generally requires removal the seat from the vehicle for adjustment. In this regard, the mechanism often requires a parent, or fitting person, to access the rear of the child safety seat to adjust the mechanism, which is generally not possible when the child safety seat is positioned in a 1o vehicle for use, with a child seated therein. Further to this, proposed mechanisms for adjusting the position of the headrest in a child safety seat require the user to use both hands to achieve the adjustment. Typically, this may involve a user having to depress two opposed mechanisms to release the headrest; or to use one hand to release the headrest and the other to move the headrest into position. In 15 either case, the user cannot simply adjust the headrest with one hand, which may be required when dealing with a child or accessing a confined space. Further to this, most child safety seats that employ a headrest portion also employ an internal harness system which is incorporated into the shell of the child safety seat. Such a harness system typically comprise straps that pass through slots or 20 similar locating means provided in the seat shell to position the straps correctly about the child so that they pass over the child's shoulders in a safe and secure manner. Therefore, in much the same way as a position of the headrest must be adjusted as a child grows, the location of the straps of the harness must also be adjusted as a child grows. In existing devices, the means for adjusting the straps 25 of the harness system and the means for adjusting the vertical position of the headrest are provided independently, thus making adjustments of the child safety seat a considerable task that requires a considerable amount of time and effort on behalf of the parent or fitting person. Thus, there is a need to provide a child safety seat of the type which employs an 30 adjustable headrest portion that can be simply adjusted with one hand without requiring removal from the position in the vehicle. It is also desirable to provide a child safety seat that provides for adjustment of the harness straps of an internal harness system at the same time as the adjustment of the headrest. The above references to and descriptions of prior proposals or products are not 35 intended to be, and are not to be construed as, statements or admissions of common general knowledge in the art. In particular, the following prior art discussion does not relate to what is commonly or well known by the person skilled in the art, but assists in the understanding of the inventive step of the present invention of which the identification of pertinent prior art proposals is but one part. STATEMENT OF INVENTION 5 According to a first aspect, there is provided a child safety seat for a vehicle comprising: a seat portion; a backrest portion mounted with respect to the seat portion; a headrest mounted to the backrest portion so as to be movable with 10 respect to the backrest portion in a vertical direction; an activation mechanism mounted on the headrest, the activation mechanism being configured such that when the activation mechanism is in a first state, movement of the headrest with respect to the backrest portion is prevented and when the activation mechanism is in a second 15 state, movement of the headrest with respect to the backrest portion is permitted; wherein, the activation mechanism is positioned on said headrest so as to be accessed by a user with one hand to facilitate adjustment of the vertical position of the headrest with respect to the backrest portion. 20 In one embodiment, the backrest portion may comprise a track formed therein into which the headrest is mounted. The track may comprise a slot extending through the backrest portion to define a vertical path along which the headrest is movable. In another embodiment, the activation mechanism comprises a button formed on 25 a surface of the headrest, the button may be rotatable between a first position defining the first state and a second position defining the second state. In one form, the second position may be orientated in a substantially 90' arc from the first position. The button may comprise a biasing means configured to bias the button in the 30 first position. The button may comprise a shaft extending therefrom. The shaft may be configured to extend through the track formed in the backrest portion such that when the button is in the first position the shaft may be prevented from sliding within the track and when the button is in the second position the shaft may be free to slide within the track. In another embodiment, the activation mechanism may comprise a lever formed 5 on a surface of the headrest. The lever may be movable between a first position defining the first state and a second position defining the second state. In one form, the lever may be provided on a top surface of the headrest. The lever may be connected to a shaft extending from the headrest and through the 10 track formed in the backrest portion such that when the lever is in the first position the shaft may be prevented from sliding within the track and when the button is in the second position the shaft may be free to slide within the track. In another form, the lever may be provided on a front surface of the headrest. the front surface of the backrest portion may be configured to engage with a rear 1s surface of the headrest portion when the lever is on the first position to prevent movement of the headrest with respect to the backrest portion, and the front portion of the backrest portion may be configured to disengage with the rear surface of the headrest portion when the lever is in the second position to facilitate movement of the headrest with respect to the backrest portion. 20 In another embodiment, the headrest may be configured to receive one or more straps of a harness system used with the child safety seat, such that adjustment of the vertical position of the headrest with respect to the backrest portion may also adjust the position of the one or more straps of the harness system with respect to a child located within the child safety seat. 25 According to a second aspect of the present invention, there is provided an adjustable headrest for a child safety seat comprising: a body configured to be positionable about a head region of a child seated in the child safety seat to provide protection to the head region of child; a mounting means for mounting the body to a child safety seat to facilitate 30 vertical movement of the body with respect to the child safety seat; and an activation mechanism mounted on the body, the activation mechanism being configured such that when the activation mechanism is in a first state, movement of the body with respect to the backrest portion is prevented and when the activation mechanism is in a second state, movement of the body with respect to the backrest portion is permitted, the activation mechanism being positioned on the body so as to be accessed by a user with one hand to facilitate adjustment of the vertical 5 position of the body with respect to the backrest portion. The mounting means may comprise a shaft extending from the body, the shaft may be configured to slidably move within a track formed in a backrest portion of the child safety seat. The shaft may be connectable to the activation mechanism such that when the 1o activation mechanism is in the first state, the shaft may be orientated into a first position that prevents slidable movement of the shaft within the track formed in the backrest portion and when the activation mechanism is in the second state, the shaft may be orientated into a second position that facilitates slidable movement of the shaft within the track formed in the backrest portion. 15 According to another aspect of the invention, there is provided a child safety seat for a vehicle comprising: a seat portion; a backrest portion mounted with respect to the seat portion; a headrest mounted to the backrest portion and movable with respect to 20 the backrest portion to facilitate adjustment of the vertical position of the headrest with respect to the backrest portion; and an activation mechanism mounted on the headrest, the activation mechanism being configured such that when the activation mechanism is in a first state, movement of the headrest with respect to the backrest 25 portion is prevented and when the activation mechanism is in a second state, movement of the headrest with respect to the backrest portion is facilitated; wherein, the activation mechanism is biased towards said first state and is positioned on said headrest so as to be accessed by a user without 30 requiring removal of the seat from the vehicle. According to one embodiment of this apsect, the activation mechanism may comprises a gripping portion that can be gripped by a user when being moved from said first state to said second state to facilitate vertical movement of the headrest with respect to the backrest portion. The activation mechanism may be provided on an outer surface of the headrest. BRIEF DESCRIPTION OF THE DRAWINGS The invention may be better understood from the following non-limiting 5 description of preferred embodiments, in which: Figure 1 is a perspective view of the a child safety seat suitable for use with the present invention; Figure 2 is a view of a headrest and backrest region of a seat in accordance with the present invention; 10 Figure 3 is rear view of a child safety seat incorporating the arrangement of Figure 2; Figure 4 is an enlarged view of a region of the seat of Figure 3; Figure 5 is a perspective view of a mounting arrangement for mounting the headrest to the backrest portion of the embodiment of Figure 2; 1s Figure 6 is a cross-sectional view of an embodiment of a headrest according to the arrangement of Figure 2; Figure 7 is a cross-sectional side view of an alternative embodiment of a child safety seat according to the present invention; Figure 8 is an enlarged view of Figure 7, showing the arrangement in an 20 'open' position; Figure 9 is an enlarged view of Figure 7, showing the arrangement in a 'closed' position; Figure 10 shows an alternative embodiment of the invention as shown in Figure 2 in a locked state; and 25 Figure 11 shows an alternative embodiment of the invention as shown in Figure 2 in an unlocked state. DETAILED DESCRIPTION OF THE DRAWINGS Preferred features of the present invention will now be described with particular reference to the accompanying drawings. However, it is to be understood that the features illustrated in and described with reference to the drawings are not to be construed as limiting on the scope of the invention. 5 The present invention will be described below in relation to a Type-B child safety seat for use in a vehicle in a forward facing manner. However, it will be appreciated that the present invention could be equally applicable for use in a variety of different modes of child safety seats, including Type A, Type B, Type A/B, Type A/B/E etc, used in a rearward or forward facing manner, and still fall 1o within the spirit of the present invention. Further, the present invention will be described below in relation to a vehicle undergoing an accident. However, it will be appreciated that the present invention can be used in a variety of vehicle situations, such as sudden breakage or acceleration of the vehicle where a child can be exposed to potentially harmful forces, without the need for the vehicle to 15 be involved in an accident or collision. Referring firstly to Figure 1, a child safety seat 10 in accordance with a preferred embodiment of the present invention is shown. The seat 10 is configured to be mounted on a seat of a vehicle to accommodate a child therein as is well understood in the art. Whilst there will be no discussion regarding the manner in 20 which the child safety seat 10 will be secured to the seat of a vehicle, it will be appreciated that this may be achieved through use of a vehicle seat belt and or an external tethering system, as would be appreciated by those skilled in the art. The seat 10 generally comprises a base portion 12 and seat shell 14. The base portion 12 is configured to be supported on a seat of a vehicle and thus has an 25 undersurface that conforms to the surface of the vehicle seat so as to provide support for the seat shell thereon. The shell 14 may be supported on the base portion such that it is movable in relation thereto, to facilitate adjustment of the angle of inclination of the shell 14 with respect to the base portion 12. The seat shell 14 comprises a seat portion 15 and a backrest portion 16. The seat 30 portion 15 is configured to receive the posterior region of a child seated therein. The backrest portion 16 extends from the seat portion 15 to support the back region of the child. In this regard, the backrest portion 16 comprises an inner surface against which the child's back region is directly supported and an outer surface against which the backrest portion 16 contacts the upper portion of the 35 vehicle seat. Whilst not shown, the seat 10 also has an internal harness system which acts to securely restrain the child within the seat 10. The internal harness system may be in the form of a common 3-point or 5-point harness system whereby a number of straps are secured to the body of the seat shell 14 so as to be connected about the child at a central point, typically at a buckle located in a crutch region of the 5 child. Slots may be provided in the backrest portion 16 to accommodate the internal harness system, as is well known in the art. A headrest 18 is mounted on the inner surface of the backrest portion 16 of the seat 10. As is shown, the headrest 18 comprises a pair of wing portions 19 that project outwards from the backrest portion 16 to extend along lateral sides of the 10 child's head region when a child is seated therein. The headrest 18 is mounted to the inner surface of the backrest portion 16 so as to be movable vertically along the backrest portion 16 as the child grows. In this regard, the vertical position of the headrest portion may be altered by sliding or otherwise moving the headrest 18 in an upward or downward manner to accommodate children of a variety of 15 different heights, or to accommodate the needs of single child as that child grows. The manner in which this is achieved will be discussed in more details below. Referring to Figure 2, the headrest 18 is mounted to the backrest portion 16 so as to be movable along a track 20. The track 20 is in the form of an elongated 20 recess extending substantially the height of the backrest portion 16 from a position adjacent to an upper end of the backrest portion to at least a position at or below a middle position along the height of the backrest. As is clearly shown in Figure 2, the track 20 extends from the inner surface to the outer surface of the backrest portion and is shaped to form a track having a plurality of spaced apart 25 circular or widened regions 21 interconnected by narrow slot regions 22. Referring Figs. 3 and 4, the rear of the seat 10 is shown in more detail. The track 20 is formed in a metal plate 23 mounted to the outer surface of the backrest portion 16. A pair of slots 25 are provided on opposing sides of an upper region of the plate 23 to provide a path for shoulder straps of the internal harness system 30 (not shown) to pass from the inner surface of the backrest portion 16 to be mounted to a mounting plate 26 located on the outer surface of the backrest portion 16. A pair of elongate slots 28 are provided to extend along opposing sides of the track 20. The slots 28 are positioned to accommodate a u-bolt 27 that projects 35 from an underside of the headrest 18. The u-bolt 18 is configured to slide along the slots 28 as the headrest 18 is moved in an upwards or downwards motion (as represented by arrow A of Fig 2) so as to provide stability of movement of the headrest for east of adjustment. It will be appreciated that the provision of the u bolt reduces likelihood of the headrest 18 twisting and becoming jammed or stuck in position as it is slid in an upward or downward direction, however, it 5 will also be appreciated that the u-bolt 27 could be replaced with other arrangements to achieve this purpose, and in some instances, the provision of a u bolt 27 may not be necessary. The headrest 18 is mounted to the backrest portion 16 of the seat shell 14 by way of a mounting arrangement 30, as is shown in Fig 5. The mounting arrangement 10 30 comprises an activation button 32 that is mounted to the headrest 18. The activation button 32 is in the form of a substantially circular button member that is recessed within the surface of the headrest 18 such that an upper surface of the button 32 is substantially flush with the surface of the headrest 18. The button 32 is mounted so as to be rotationally movable in the direction of arrow B between a 15 substantially 90 degree arc, as will be discussed in more detail below. An elongate shaft member 34 extends from the activation button 32 so as to pass through the track 20 provided through the backrest portion 16. In this regard, the length of the shaft member 34 is sufficient to be substantially equivalent to the width of the backrest portion 16 such that a washer 36 and locking nut 38 are 20 located against the outer surface of the backrest portion to be substantially flush with the plate 23, as is shown in Figs. 3 and 4. In this regard, the surface of the washer 36 is substantially smooth so as to facilitate slidable motion over the surface of the plate 23 when the position of the headrest 18 is adjusted. Referring to Fig. 5, the elongate shaft member 34 has a neck portion 33 formed 25 therein. The neck portion 33 is formed to comprise that portion of the elongate shaft member that extends through the track 20. The shaft member 34 is formed from a tubular element, such as a steel or plastic rod or the like, having a substantially circular cross section. The neck portion 33 is formed by removing a portion of material from a top and a bottom surface of the shaft member 34, as is 30 shown. In this regard, when the shaft member is orientated in a first position, such as that shown in Fig. 5, the neck position 33 presents a width substantially equivalent to the width of the remainder of the elongate shaft member 34. However, when the elongate shaft member 34 is turned through an arc of 90 degrees, the neck portion 33 presents a width significantly narrower than the 35 width of the remainder of the elongate shaft member 34. With such a mounting arrangement 30 as shown in Fig. 5, by rotating the activation button 32 through an arc of 90 degrees, the neck portion 33 can be orientated so as to extend vertically. In this position, the headrest 18 can be moved in a vertical position, thereby causing the neck portion 33 to freely travel along track 20, namely along the narrow slot regions 22 and the widened regions 21, so as to be positioned at any desired height along the backrest portion 16. By 5 allowing the mounting arrangement to return to its biased position through travelling a 90 degree arc, the wide portion of the neck region 33 will rotate to extend in a horizontal manner, and as the width of the elongate shaft member 34 is wider than the slot regions 22 of the track 20, further vertical movement of the headrest 18 will be prevented and the headrest 18 will be locked in position. 10 As is shown in Figure 5, a spring member 35 is mounted to an undersurface of the activation button 32. The spring member 35 is a torsion spring having one arm 35a fixed in position with respect to the button 32, and the other end 35b free. When the button 32 is mounted within the recess 17 formed in the headrest 18 (see Fig. 6) the free end 35b of the spring member 35 abuts against a lip 17a 15 formed in the recess 17. This arrangement acts to limit the amount of rotational movement of the button 32 such that it cannot be rotated through more than a 90' arc. The spring 35 is further arranged to act as a bias such that the button 32 is always biased towards a closed or locked position where by the mounting arrangement 30 prevents vertical adjustment of the headrest 18. 20 In the embodiment as shown in Figs 2-6, the headrest 18 has a pair of guides 11 formed therein. The guides 11 act to receive the shoulder straps of the harness system of the seat 10 as they pass through the guides 11 and the slots 25 to the rear surface of the backrest portion 16. Thus it will be appreciated that by adjusting the position of the headrest 18, the location of the shoulder straps of the 25 harness system will also be adjusted in accordance therewith, thus reducing the need to perform multiple adjustment tasks. Further to this, such a combined headrest adjustment and harness adjustment only requires the provision of a single pair of slots 25 formed in the backrest 16 for receiving the shoulder straps. Typically, in order to adjust the shoulder strap positions in conventional safety 30 seats, multiple slots 25 have been required to enable adjustment of the position of the should straps with respect to the height of the child. By overcoming the need to form multiple slots 25 in the backrest, the construction and design of the seat can be greatly simplified. Referring to Figure 2, it will be appreciated that the embodiment of the present 35 invention as shown in Figs. 2 - 6 provides the adjustment at the front of the seat 10, namely the activation button 32 is located on the surface of the headrest 18, thus providing an easy to access means of performing the adjustment. By simply rotating the button 32 through an arc of 90' and applying vertical pressure through the headrest, the headrest can be vertically adjusted to a child's needs, together with the harness shoulder straps, simply and with one hand and without requiring removal of the seat from the vehicle or to perform multiple adjustment 5 tasks. A variation of the embodiment of the present invention of Figures 2 - 6 is shown in Figures 10 and 11. In describing this embodiment, similar reference numerals will be used to refer to similar features as described above in relation to the embodiment of Figures 2 - 6. 10 As is shown in Figure 10, in order to provide adjustment of the headrest 18, a lever mechanism 80 is provided along an upper or top edge of the headrest. The lever mechanism 80 is formed to substantially conform to the contour of the upper edge of the headrest 18 and is pivotally mounted to the headrest 18 at one end, with the other end being free to be lifted by a user. In this regard a recess 82 1s may be formed in the headrest 18 immediately below the free end of the lever mechanism 80 to assist a user in lifting the free end of the lever mechanism in the direction of the arrow as shown in Figure 11. A connector member 84 is connected to the free end of the lever mechanism 80 and extends to be attached to an underside of the shaft member 34 as represented 20 by the hashed lines in Figure 10. The connector member 84 may be in the form of an inextensible length of wire, string or the like that acts to impart a rotational motion to the shaft member 34 of the mounting arrangement 30 as the lever mechanism 80 is lifted in the manner as shown in Figure 11. By lifting the lever mechanism 80 in the manner as shown in Figure 11, the shaft 25 member 34 of the mounting arrangement 30 is caused to move through a 90' arc, thereby enabling the position of the headrest 18 to be adjusted as required. It will be appreciated that as the lever mechanism is provided in the upper or top edge of the headrest 18, the headrest 18 can be adjusted in a simple one-handed motion. It will be appreciated that other means for achieving such one-handed 30 adjustment of the headrest position are also envisaged, including an arrangement whereby the lever mechanism 80 is depressed rather than lifted. It will be appreciated that in the embodiment of Figures 10 and 11, the lever mechanism 80 may be employed instead of, or in addition to, the button 32 Referring to Figures 7 - 9, an alternative embodiment of the present invention is 35 shown. In this embodiment, a mounting arrangement 50 is provided to mount the headrest 18 to the backrest portion 16 of the seat 10. The mounting arrangement 50 comprises a bolt 52 that extends through the headrest 18 and is received within an elongate slot (not shown) formed vertically along at least a portion of the height of the backrest 16. A securing nut 54 is provided in the backrest portion to secure an end of the bolt 52 in position with respect to the backrest 5 portion 16. The other end of the bolt 52 extends to a front surface of the headrest 18 and has a lever 56 mounted thereto. The lever 56 is mounted within a recess 55 formed in the front surface of the headrest 18, such that when the lever 56 is in a locked position the lever 56 is retained fully within the recess 55 and does not project beyond the front surface of the headrest 18. 10 The inner surface of the backrest portion 16, namely the surface along which the headrest 18 travels, is configured to provide a surface having a plurality of peaks 41 and troughs 42 formed thereon. The undersurface of the headrest 18 is provided with a plurality of projections 45 that project therefrom, towards the inner surface 40 of the backrest portion 16. The projections 45 are shaped such 15 that they substantially conform to the shape of the troughs 42 in the inner surface of the backrest portion 16. The mounting arrangement 50 is configured such that when the lever is in a first or opened position (Fig. 8) the headrest 18 is loosely mounted against the inner surface 40 of the backrest portion 16, such that the headrest 18 is able to be freely 20 movable along the inner surface 40 of the backrest portion 16 in the direction of arrow C. By turning the lever 56 such that it is moved to a locked or closed position (Fig. 9) the undersurface of the headrest 18 is brought into firm contact with the inner surface 40 of the backrest portion 16 such that the projections 45 are pressed into position within the troughs 42 formed on the surface 40. This 25 then locks the headrest 18 in position against the backrest portion 16. It will be appreciated that a torsion spring mechanism may be employed with the lever 56 to bias the lever 56 into a closed position where it is received within the recess 55 of the headrest 18. In the embodiment of the present invention as shown in Figures 7 - 9, the vertical 30 position of the headrest 18 can be simply adjusted by one hand through lifting the lever 56 and moving the headrest into the desired vertical position. It will be appreciated that the child safety seat of the present invention provides a simple and effective mechanism for adjusting the position of the head rest and/or the harness system from a front-on position without requiring removal of the seat 35 from the vehicle. The present invention can be simply activated with one hand and in a single motion, and can be readily activated and biased towards a closed position for added safety and security. Throughout the specification and claims the word "comprise" and its derivatives are intended to have an inclusive rather than exclusive meaning unless the contrary is expressly stated or the context requires otherwise. That is, the word 5 "comprise" and its derivatives will be taken to indicate the inclusion of not only the listed components, steps or features that it directly references, but also other components, steps or features not specifically listed, unless the contrary is expressly stated or the context requires otherwise. It will be appreciated by those skilled in the art that many modifications and 1o variations may be made to the methods of the invention described herein without departing from the spirit and scope of the invention. Orientational terms used in the specification and claims such as vertical, horizontal, top, bottom, upper and lower are to be interpreted as relational and are based on the premise that the component, item, article, apparatus, device or 15 instrument will usually be considered in a particular orientation, typically with the child safety seat uppermost.

Claims (18)

1. A child safety seat for a vehicle comprising: a seat portion; a backrest portion mounted with respect to the seat portion; a headrest mounted to the backrest portion so as to be movable with respect to the backrest portion in a vertical direction; an activation mechanism mounted on the headrest, the activation mechanism being configured such that when the activation mechanism is in a first state, movement of the headrest with respect to the backrest portion is prevented and when the activation mechanism is in a second state, movement of the headrest with respect to the backrest portion is permitted; wherein, the activation mechanism is positioned on said headrest so as to be accessed by a user with one hand to facilitate adjustment of the vertical position of the headrest with respect to the backrest portion.

2. A child safety seat according to claim 1, wherein the backrest portion comprises a track formed therein into which the headrest is mounted.

3. A child safety seat according to claim 2, wherein the track comprises a slot extending through the backrest portion to define a vertical path along which the headrest is movable.

4. A child safety seat according to claim 2 or 3, wherein the activation mechanism comprises a button formed on a surface of the headrest, the button being rotatable between a first position defining the first state and a second position defining the second state.

5. A child safety seat according to claim 4, wherein the second position is orientated in a substantially 90' arc from the first position.

6. A child safety seat according to claim 2, wherein the button comprises a biasing means configured to bias the button in the first position.

7. A child safety seat according to any one of claims 4 to 6, wherein the button comprises a shaft extending therefrom, the shaft being configured to extend through the track formed in the backrest portion such that when the button is in the first position the shaft is prevented from sliding within the track and when the button is in the second position the shaft is free to slide within the track.

8. A child safety seat according to claim 2 or 3, wherein the activation mechanism comprises a lever formed on a surface of the headrest, the lever being movable 14 between a first position defining the first state and a second position defining the second state.

9. A child safety seat according to claim 8, wherein the lever is provided on a top surface of the headrest.

10. A child safety seat according to claim 9, wherein the lever is connected to a shaft extending from the headrest and through the track formed in the backrest portion such that when the lever is in the first position the shaft is prevented from sliding within the track and when the button is in the second position the shaft is free to slide within the track.

11. A child safety seat according to claim 8, wherein the lever is provided on a front surface of the headrest.

12. A child safety seat according to claim 11, wherein a front surface of the backrest portion is configured to engage with a rear surface of the headrest portion when the lever is on the first position to prevent movement of the headrest with respect to the backrest portion, and the front portion of the backrest portion is configured to disengage with the rear surface of the headrest portion when the lever is in the second position to facilitate movement of the headrest with respect to the backrest portion.

13. A child safety seat according to any one of the preceding claims, wherein the headrest is configured to receive one or more straps of a harness system used with the child safety seat, such that adjustment of the vertical position of the headrest with respect to the backrest portion also adjusts the position of the one or more straps of the harness system with respect to a child located within the child safety seat.

14. An adjustable headrest for a child safety seat comprising: a body configured to be positionable about a head region of a child seated in the child safety seat to provide protection to the head region of child; a mounting means for mounting the body to a child safety seat to facilitate vertical movement of the body with respect to the child safety seat; and an activation mechanism mounted on the body, the activation mechanism being configured such that when the activation mechanism is in a first state, movement of the body with respect to the backrest portion is prevented and when the activation mechanism is in a second state, movement of the body with respect to the backrest portion is permitted, the activation mechanism being positioned on the body so as to be accessed by a user with one hand to facilitate 15 adjustment of the vertical position of the body with respect to the backrest portion.

15. An adjustable headrest according to claim 14, wherein the mounting means comprises a shaft extending from the body, the shaft being configured to slidably move within a track formed in a backrest portion of the child safety seat.

16. An adjustable headrest according to claim 15, wherein the shaft is connectable to the activation mechanism such that when the activation mechanism is in the first state, the shaft is orientated into a first position that prevents slidable movement of the shaft within the track formed in the backrest portion and when the activation mechanism is in the second state, the shaft is orientated into a second position that facilitates slidable movement of the shaft within the track formed in the backrest portion.

17. A child safety seat substantially as hereinbefore described with reference to any one of Figures 2 - 11.

18. An adjustable headrest substantially as hereinbefore described with reference to any one of Figures 2 - 11. 16