Child safety seat

1. A child safety seat comprising:

a seat shell comprising a seat portion and a back portion; and

an adjustable backrest comprising a first end which is slidably and pivotally secured with respect to the back portion, and a second end configured to bear against a supporting surface provided on the seat shell, wherein the backrest is configured to be moveable with respect to the seat shell between a lowermost position, where the second end of the backrest is moved away from the back portion and closer to a front edge of the seat portion, reducing the available seating area for an occupant of the seat, and an uppermost position, where the second end of the backrest is moved away from the front edge of the seat portion and closer to the back portion of the seat shell, increasing the available seating area for the occupant of the seat,

wherein the backrest and supporting surface are configured such that the backrest is able to be moved up and down between the uppermost position and a defined position in between the uppermost position and the lowermost position, without a change in the available seating area, and wherein the backrest is able to be moved up and down between the defined position and the lowermost position with a change in the available seating area

wherein the second end of the backrest comprises at least one projection configured to bear against the supporting surface provided on the seat shell.

2. The child safety seat as claimed in claim 1 , wherein the seat shell comprises at least one recess configured to accommodate the at least one projection, the recess provided along a portion of the supporting surface, the recess extending from a first position corresponding to the uppermost position of the backrest to a second position corresponding to the defined position with relation to the back portion, the recess configured such that the backrest is able to move up and down between the uppermost position and the defined position without a change in the available seating area.

3. The child safety seat as claimed in claim 1 , further comprising a headrest configured to be slidably secured with respect to the back portion of the seat shell, and moveable between an upper position and a lower position, and to which the backrest is pivotally connected, such that the backrest and headrest move together.

4. A child safety seat comprising:

a seat shell comprising a seat portion and a back portion; and

an adjustable backrest comprising an upper end which is slidably and pivotally secured with respect to the back portion, and a lower end configured to bear against a support surface provided on the seat shell, wherein the backrest is configured to be moveable with respect to the seat shell between a lowermost position, where the lower end of the backrest is moved away from the back portion and closer to a front edge of the seat portion, reducing the available seating area for an occupant of the seat and increasing an incline angle of the backrest with respect to the back portion, and an uppermost position, where the second end of the backrest is moved away from the front edge of the seat portion and closer to the back portion of the seat shell, increasing the available seating area for the occupant and decreasing the incline angle of the backrest with respect to the back portion,

wherein the backrest is able to be moved up and down between the uppermost position and a defined position between the uppermost and lowermost positions, without a change in the incline angle of the backrest, and wherein the backrest is able to be moved up and down between the defined position and the lowermost position, with a change in the incline angle of the backrest

wherein the lower end of the backrest comprises at least one projection configured to bear against the supporting surface provided on the seat shell.