Child safety seat

1. A child safety seat comprising:

a seat shell including a backrest having a lengthwise axis;

a headrest assembled with the seat shell and movable along the lengthwise axis of the backrest; and

a headrest adjustment mechanism including:

two tube segments affixed with the backrest;

a mount frame affixed with the headrest, the mount frame being movable along the tube segments during adjustment of the headrest relative to the backrest;

two latches assembled with the mount frame, wherein the latches are operable to move transversally relative to the headrest to respectively engage with the two tube segments to lock the headrest in position, and to respectively disengage from the tube segments to allow adjustment of the headrest; and

a driving part connected with the two latches, the driving part having a lower portion provided with two guide slots that are inclined symmetrically relative to an axis of displacement of the driving part, and the two latches having portions that are respectively connected through the two guide slots, wherein the driving part is movable along the lengthwise axis to cause the latches to respectively disengage from the tube segments.

2. The child safety seat according to claim 1 , wherein the latches are movable along a direction that is perpendicular to an axis of displacement of the driving part.

3. The child safety seat according to claim 1 , wherein the driving part is disposed centrally between the two tube segments.

4. The child safety seat according to claim 1 , wherein the driving part moves upward to drive the two latches in movement toward each other to disengage from the two tube segments.

5. The child safety seat according to claim 1 , wherein the tube segments respectively include a plurality of locking openings, and the latches are operable to engage with any ones of the locking openings to lock the headrest at a desired position relative to the backrest.

6. A child safety seat comprising:

a seat shell including a backrest having a lengthwise axis;

a headrest assembled with the seat shell and movable along the lengthwise axis of the backrest; and

a headrest adjustment mechanism including:

two tube segments affixed with the backrest;

a mount frame affixed with the headrest, the mount frame being movable along the tube segments during adjustment of the headrest relative to the backrest;

two latches assembled with the mount frame, wherein the latches are operable to move transversally relative to the headrest to respectively engage with the two tube segments to lock the headrest in position, and to respectively disengage from the tube segments to allow adjustment of the headrest;

a driving part connected with the two latches, wherein the driving part is movable along the lengthwise axis to cause the latches to respectively disengage from the tube segments; and

a release actuator pivotally assembled with the headrest, the release actuator having a lower portion connected with the driving part, such that a rotation of the release actuator causes displacement of the driving part along the lengthwise axis.

7. The child safety seat according to claim 6 , wherein the headrest includes a pocket in which the release actuator is received.

8. The child safety seat according to claim 6 , wherein the release actuator is formed as one single part that is connected with the driving part.

9. The child safety seat according to claim 6 , wherein the release actuator has a lower portion assembled with a plurality of slots provided in an upper portion of the driving part.

10. The child safety seat according to claim 1 , wherein the headrest adjustment mechanism further includes a spring having two ends respectively anchored with the driving part and the headrest, the spring being operable to create a biasing force to urge the driving part to move in a direction for causing the latches to respectively engage with the tube segments.

11. The child safety seat according to claim 1 , wherein the mount frame includes two sleeves through which the tube segments are disposed, the sleeves being movable along the tube segments.

12. The child safety seat according to claim 1 , wherein the mount frame further includes two strap-routing slots through which shoulder straps of the child safety seat are routed.

13. The child safety seat according to claim 11 , wherein the two latches are movable to respectively extend into the two sleeves to engage with the two tube segments.

14. A child safety seat comprising:

a seat shell including a backrest having a lengthwise axis;

a headrest assembled with the seat shell and movable along the lengthwise axis of the backrest; and

a headrest adjustment mechanism including:

two tube segments affixed with the backrest;

a mount frame affixed with the headrest, the mount frame being movable along the tube segments during adjustment of the headrest relative to the backrest;

two latches assembled with the mount frame, wherein the latches are operable to move transversally relative to the headrest to respectively engage with the two tube segments to lock the headrest in position, and to respectively disengage from the tube segments to allow adjustment of the headrest; and

a driving part connected with the two latches, wherein the driving part is movable along the lengthwise axis to cause the latches to respectively disengage from the tube segments;

wherein the mount frame includes a transversal segment having two elongated slots, the driving part includes two guide slots that respectively overlap at least partially with the elongated slots and respectively extend at an angle relative to the elongated slots, and the two latches are assembled in the transversal segment and are respectively connected with the elongated slots of the transversal segment and the guide slots of the driving part.