GB2482410A

GB2482410A - Child safety seat

Info

Publication number: GB2482410A
Application number: GB201112876A
Authority: GB
Inventors: da-liang Zhang
Original assignee: BP Childrens Products HK Co Ltd
Current assignee: BP Childrens Products HK Co Ltd
Priority date: 2010-07-26
Filing date: 2011-07-26
Publication date: 2012-02-01
Anticipated expiration: 2031-07-26
Also published as: GB2482410B; GB201112876D0; CN102343846B; CN102343846A

Abstract

A child safety seat comprises a seat portion and a backrest assembly 102 coupled with the seat portion. The backrest assembly 102 includes a first support portion 104 having a row of grooves 1083, a second support portion 105 movably assembled with the first support portion 104, and a latch mechanism 103 including a latching element 106 movably mounted with the second support portion 105. The latching element 106 includes at least one elastically deformable bent arm 1063, and an engagement end 1064 at a distal end of the bent arm 1063. The latching element 106 can move along a first path to drive displacement of the bent 1063 arm and cause the engagement end 1064 to move along a second path to disengage or engage with a groove 1083. When the engagement end 1064 is disengaged from the groove 1083, the latch mechanism 103 is unlocked and the second support portion 105 is adjustable relative to the first support portion 104. When the engagement end 1064 is engaged with the groove 1083, the second support portion 105 is locked with the first support portion 104.

Description

CHILD SAFETY SEAT

[00011 This application claims priority of China patent application no. 201010239885.2 filed on July 26, 2010, and China patent application no. 201010279949.1 filed on September 9, 2010.

[00021 The present invention relates to a child safety seat having an adjustable backrest assembly.

[00031 Vehicle seats are usually designed to accommodate adults, and are not suitable to seat young children. Accordingly, current safety legislations require the use of a child safety seat to seat a young child in a vehicle.

[0004] A child safety seat usually includes a headrest, a backrest and a waist rest that are designed in accordance with the size of the child's head and body. Once the child is adequately installed, the child safety seat can safely restrain the child in position as the vehicle is advancing. In addition, the conventional child safety seat may also be provided with some height adjustment mechanism to accommodate a growing child at different ages. However, the current construction of the height adjustment mechanism is usually complex. Moreover, because the conventional construction of the child safety seat cannot be conveniently collapsed or disassembled, the child safety seat requires a substantial amount of packaging material for shipment.

[0005] Therefore, there is a need for a child safety seat that can be more convenient to operate, can reduce the manufacture cost and address at least the forgoing issues.

100061 The present application describes a child safety seat having an adjustable backrest assembly that can be easily dismounted, and have a latch mechanism which is convenient to operate for adjusting the height of the backrest assembly.

[00071 Viewed from one aspect the present invention provides a child safety seat comprising: a seat portion; and a backrest assembly coupled with the seat portion, the backrest assembly including: a first support portion having a row of grooves; a second support portion movably assembled with the first support portion; and a latch mechanism including a latching element movably mounted with the second support portion and extending toward the first support portion, wherein the latching element includes at least one elastically deformable bent arm, and an engagement end at a distal end of the bent arm, wherein the latching element is operable to move along a first path to drive displacement of the bent arm and cause the engagement end to move along a second path to disengage or engage with one of the grooves, when the engagement end is disengaged from the groove, the latch mechanism is unlocked and the second support portion is adjustable relative to the first support portion, when the engagement end is engaged with the groove, the latch mechanism locks the second support portion with the first support portion.

100081 In one embodiment, the child safety seat comprises a seat portion, and a backrest assembly coupled with the seat portion. The backrest assembly can include a first support portion having a row of grooves, a second support portion movably assembled with the first support portion, and a latch mechanism including a latching element movably mounted with the second support portion. The latching element includes at least one elastically deformable bent arm, and an engagement end at a distal end of the bent arm. The latching element is operable to move along a first path to drive displacement of the bent arm and cause the engagement end to move along a second path to disengage or engage with one of the grooves. When the engagement end is disengaged from the groove, the latch mechanism is unlocked and the second support portion is adjustable relative to the first support portion. When the engagement end is engaged with the groove, the latch mechanism locks the second support portion with the first support portion.

[00091 Viewed fiom another aspect the present invention provides a child safety seat comprising: a seat portion; and a backrest assembly including: a first support portion detachably connected with the seat portion; a second support portion detachably assembled with the first support portion; and a latch mechanism assembled between the first and the second support portions, the latch mechanism having* a locked state for holding the second support portion in place relative to the first support portion, and an unlocked state allowing adjustment of the second support portion relative to the first support portion.

[0010] In the child safety seat described herein, the backrest assembly has a latch mechanism that is simple in construction, and can be easily operated to adjust the height of the backrest assembly as well as for dismounting and assembly operations.

Accordingly, the child safety seat can be more versatile in use.

[0011] Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, wherein: [0012] Figure 1 is a schematic rear view illustrating one embodiment of a child safety seat; [0013] Figure 2 is an exploded view illustrating a backrest assembly in the child safety seat shown in Figure 1; [0014] Figure 3 is an enlarged view illustrating a portion of the backrest assembly; [0015] Figure 4 is a schematic view illustrating the assembly of the first and second support portions in the backrest assembly; [0016] Figure 5 is a schematic view illustrating a latch mechanism provided in the backrest assembly in an unlocked state; [0017] Figure 6 is a schematic view illustrating the second support portion in the backrest assembly adjusted to a height different from that of Figure 4; [0018] Figure 7 is a schematic view illustrating a construction of a limiting structure adapted to limit an upward course of the second support portion in the backrest assembly; [0019] Figure 8 is a schematic view illustrating the disassembly of the second support portion from the first support portion in the backrest assembly; [00201 Figure 9 is a schematic view illustrating a variant embodiment for creating interference between engagement ends and a variant construction of a limiting structure in the backrest assembly; [0021] Figure 10 is a schematic view illustrating another limiting structure adapted to prevent disengagement of the second support portion from the first support portion in the backrest assembly; and [0022] Figures 11 through 13 are schematic views illustrating the child safety seat in three different configurations of use.

[0023] The present application describes a child safety seat including a bottom seat portion and a backrest assembly. The backrest assembly includes first and second support portions adjustable relative to each other, and a latch mechanism assembled between the first and second support portions. The latch mechanism uses a latching element having a curved resilient portion that is operable to achieve locking and unlocking. The latch mechanism is simple in construction, which can reduce the amount of component parts and manufacture cost. Moreover, the latch mechanism conveniently permits easy assembly and disassembly of the backrest assembly.

[00241 Figure 1 is a schematic rear view illustrating one embodiment of a child safety seat 100, Figure 2 is an exploded view illustrating a backrest assembly 102 of the child safety seat 100, and Figure 3 is an enlarged view illustrating a portion of the backrest assembly 102. The child safety seat 100 can include a seat portion 101 and a backrest assembly 102. The backrest assembly 102 can be movably assembled with the seat portion 101 to define a space that can receive a child. In an embodiment, the backrest assembly 102 can include three joining portions 1 02A (for example C-shaped clamp), and the seat portion 101 can include coupling elements I O1A (for example rod * portions) that can pivotally mount with the joining portions 1 02A to detachably connect the backrest assembly 102 with the seat portion 101. It will be understood that the seat portion 101 and the backrest assembly 102 can be connected with each other via other constructions. In addition, fabric andlor flexible materials (not shown) may be mounted with the seat portion 101 and the backrest assembly 102 to provide

comfortable support.

10025] The backrest assembly 102 can comprise a first support portion 104, a second support portion 105, and a latch mechanism 103 assembled between the first and second support portions 104 and 105. The first support portion 104 can be exemplary a waist rest adapted to provide support for a waist portion of the seated child. The second support portion 105 can include a backrest region 109, a headrest region 110 connected with a first side.of the backrest region 109, and a pillar 107 connected with the backrest region 109 at a side opposite to the headrest region 110. In one embodiment, the second support portion 105 (including the pillar 107, the backrest region 109 and the headrest region 110) can be formed in an integral body. The pillar 107 can have a generally "M"-shaped cross-section that is movably mounted through a guide slot 108 provided in the first support portion 104. The second support portion can thereby move vertically up and down relative to the first support portion 104 to increase or reduce a distance between the first and second support portions 104 and 105, whereby the height of the second support portion 105 relative to the first support portion 104 can be adjusted to suit the height of the child. Moreover, the left and right sides of the first and second support portions 104 and 105 can respectively bend to form lateral wings 1 04A, 1 09A and 11 OA adapted to provide lateral resting support.

10026] As shown in Figure 2, the guide slot 108 is located approximately at a central area of the first support portion 104, and can have a generally "M"-shaped cross-section including multiple sidewalls 108A, 108B, 108C and 108D. The sidewall 108A can correspondingly face a front surface of the pillar 107, the sidewall 108B can correspondingly face a rear surface of the pillar 107, and the sidewalls I 08C and I 08D are respectively parallel to the left and right side edges of the pillar 107. Two opposite side regions of the sidewall 108A can include two rows of grooves 1083 through which the latch mechanism 103 can effect locking engagement to hold the second support portion 105 at different heights relative to the first support portion 104. The construction of the latch mechanism 103 and its interaction with the grooves 1083 will be described in more details hereafter.

100271 Referring again to Figure 2, the latch mechanism 103 can include a movable latching element 106 and a spring 111. The latching element 106 can comprise an actuator portion 1061, a lengthwise extension 1062, a pair of bent arms 1063 elastically deformable, and two engagement ends 1064. The actuator portion 1061 can be fixedly joined with a first end portion of the extension 1062. Each of the bent arms 1063 is connected with a second end portion of the extension 1062 opposite to the actuator portion 1061. The engagement ends 1064 are respectively provided at the distal ends of the bent arms 1063. Each of the bent arms 1063 can be made of an elastic material that can be subject to elastic deformation (i.e., the bent arms 1063 can elastically deform upon application of an external force, and recover an initial shape upon removal of the external force). The bent arms 1063 can respectively bend outward toward the left and right sides to form a generally T-shape. As the latching element 106 moves relative to the second support portion 105 along a first path (e.g., upward or downward in Figure 2), each of the bent arms 1063 can be driven to slide and elastically deform to cause displacement of the associated engagement end 1064 along a second path (e.g., in a transverse direction toward the left/right side in Figure 2) to engage with or disengage from a corresponding groove 1083, thereby effecting locking and unlocking of the latch mechanism 103. To effect firmer engagement, a width W of the engagement end 1064 can be gieater than that of the bent arm 1063. While the illustrated embodiment uses two bent arms 1063 and engagement ends 1064, alternate embodiments may use one single bent armlengagement end, or more than two bent arms/engagement ends.

100281 Figure 3 is a schematic view illustrating the assembly of the latching element 106 with the second support portion 105. The latching element 106 can be movably mounted in a channel 1051 formed at a rear of the second support portion 105 for vertically up and down movements. The channel 1051 can have side edges provided with restrain ribs 1053 (as shown in Figure 1) that can prevent lateral disengagement of the latching element 106 from the channel 1051 when the latching element 106 is sliding vertically. Moreover, the latching element 106 can include a restrain slot 1065 along the axial direction of the extension 1062, and the rear of the second support portion 105 can include a stud 1055 that can be movably engaged in the restrain slot 1065. The spring 111 can be mounted between the stud 1055 and an anchor rib 1066 provided on the latching element 106. A fastener element 113 (e.g., restrain screw) can be engaged through the stud 1055 to prevent the latching element 106 from disengaging from the channel 1051 of the second support portion 105. In this manner, the vertical movement of the latching element 106 relative to the second support portion 105 can be limited in range by the restrain slot 1065.

100291 Figure 4 is a schematic view illustrating the assembly of the first and second support portions 104 and 105. For clarity, the representation of the sidewall 1 08B is omitted in Figure 4 to better show the assembly of the pillar 107 and the latch mechanism 103 in the guide slot 108. When it is assembled with the second support portion 105, the latching element 106 can extend along a lengthwise axis of the second support portion 105 to the first support portion 104. The actuator portion 1061 can be placed adjacent to the headrest region 110. The lengthwise extension 1062 can be placed along the backrest region 109 and the pillar 107. The bent arms 1063 and the engagement ends 1064 can be placed proximate to a lower end of the pillar 107. A rear of the pillar 107 can include a plurality of guide ribs 1072 (better shown in Figure 7) disposed at positions adjacent to spaced-apart portions of the bent arms 1063. The guide ribs 1072 can contact and guide the displacement and deformation of the bent arms 1063. The bent anus 1063 can respectively bend toward the left and right sides of the pillar 107, i.e., toward the sidewalls 108E and 108F of the guide slot 108, such that the engagement ends 1064 can respectively pass through the left and right sidewalls 1074 of the pillar 107. Movements of the latching element 106 can drive displacement and elastic deformation of the bent arms 1063, which in turn cause the engagement ends 1064 that extend outward from the two opposite sidewalls 1074 to disengage or engage with a pair of corresponding grooves 1083 in the first support portion 104. The latching mechanism 103 can be thereby switched to unlocked and locked states. In one embodiment, the movement path of the latching element 106 can be substantially perpendicular to the movement path of the engagement ends 1064, e.g., the latching element 106 may move up and down along the lengthwise axis of the backrest assembly 102 to drive transverse displacement of the engagement ends 1064.

10030] A stop element 1101 can be provided at a rear of the headrest region 110.

The stop element 1101 can be disposed on the second support portion 105 at a location adjacent to the actuator portion 1061. When the latching element 106 is moving upward along the lengthwise axis, the stop element 1101 can abut against the actuator portion 1061 to limit the upward course of the latching element 106 and stop the latching element 106 at the unlocked position. In one embodiment, the stop element 1101 can be formed as a resilient tab that protrudes from the second support portion 105, and can be elastically deflect to disengage from the actuator portion 1061 and extend the upward course of the latching element 106.

[0031] Exemplary operation for adjusting the second support portion 105 relative to the first support portion 104 is described hereafter with reference to Figures 4, and 6. In Figure 4, the engagement ends 1064 of the latching element 106 extend outward from the opposite sidewalls 1074 of the pillar 107, and respectively engage with a pair of corresponding grooves 1083 in the first support portion 104.

Accordingly, the latch mechanism 103 is in a locked state to hold the height of the second support portion 105 relative to the first support portion 104.

[00321 Figure 5 is a schematic view illustrating the latch mechanism 103 in an unlocked state. When the height of the second support portion 105 is to be adjusted, the latching element 106 has to be pulled upward until the actuator portion 1061 abuts against the stop element 1101. As a result, the bent arms 1063 can be pulled upward concurrently. . Owing to the interaction of the guide ribs 1072, the displacement of the bent arms 1063 can cause a deformation that reduces the transverse length of the bent arms 1063, and cause the engagement ends 1064 to disengage from the grooves 1083.

The limiting abutment of the stop element 1101 can prevent the engagement ends 1064 from disengaging from the opposite sidewalls 1074 of the pillar 107 and maintain the latch mechanism 103 in the unlocked state. While the latching element 106 is kept in abutment against the stop element 1101 in the unlocked state, the second support portion 105 can be vertically moved relative to the first support portion 104 to reduce or increase the height of the second support portion 105. When the second support portion 105 is being adjusted, the latching element 106 and spring 111 assembled on the second support portion 105 are also moved in unison.

100331 Figure 6 is a schematic view illustrating the second support portion 105 adjusted to a height different from that of Figure 4. Once the second support portion is adjusted to a desired height, the latching element 106 can be released. As a result, the spring 111 can urge the latching element 106 to move toward the first support portion 104. As the latching element 106 is moving downward, the bent arms 1063 can displace and elastically deform due to the interaction with the guide ribs 1072, which push the engagement ends 1064 in locking engagement with another pair of corresponding grooves 1083. The latch mechanism 103 can thereby recover its locked state to hold the second support portion 105 at the desired height relative to the first support portion 104.

100341 To prevent disengagement of the second support portion 105 from its connection with the first support portion 104, the first support portion 104 can include a.

limiting structure 116. When the second support portion 105 moves upward, the limiting structure 116 can interfere with the engagement ends 1064 to prevent excessive upward adjustment of the second support portion 105. Figure 7 is a schematic view illustrating a construction of the limiting structure 116 adapted to limit the upward course of the second support portion 105. The limiting structure 116 can be disposed adjacent to the uppermost grooves 1083A in the two rows of the grooves 1083. The limiting structure 116 can be exemplary formed as protruding ribs that respectively project from the sidewalls 108E and 108F toward the pillar 107 (Figure 7 only shows a portion of the limiting structure 116 provided on the sidewall 108E, the other sidewall I 08F can be symmetrically provided with the same limiting structure 116). While the latch mechanism 103 is in the unlocked state and the second support portion 105 is being adjusted upward, the engagement ends 1064 can abut against the limiting structure 116 to prevent excessive upward displacement that may move the engagement ends 1064 beyond the uppermost grooves I 083A. Accordingly, the latch mechanism 103 is restricted to operate in a predetermined allowable range of adjustment, which can ensure safer use.

[0035] Figure 8 is a schematic view illustrating the disassembly of the second support portion 105 from the first support portion 104. First, the stop element 1101 is operated to disengage from its blocking position with respect to the latching element 106. For example, the stop element 1101 can be depressed out of the movement path of the latching element 106, such that the upward adjustment course of the latching element 106 can be increased. Because the stop element 1101 is formed as a resilient tab, the stop element 1101 can elastically deflect to remove the interference with the actuator portion 1061. Subsequently, the latching element 106 can be further moved upward to pass by the stop element 1101 to a dismount position, which also drives the engagement ends 1064 to further move toward a central region of the pillar 107 to respectively disengage from the locking positions of the limiting structure 116 (as shown with phantom lines in Figure 7). As the obstruction of the limiting structure 116 is removed, the second support portion 105 can be easily disassembled from the first support portion 104.

[0036] For assembling the second support portion 105 with the first support portion 104, the pillar 107 of the seccnd support portion 105 can be inserted into the guide slot 108 of the first support portion 104. As the latching element 106 is moving downward, the engagement ends 1064 extending outward from the opposite sidewalls 1074 can push against angled surfaces 11 6A provided at an upper side of the limiting structures 116, which urges the engagement ends 1064 to respectively move away from the limiting structures 116, e.g., toward the central region of the pillar 107. As a result, the second support portion 105 can further move toward the first support portion 104.

Once the engagement ends 1064 have moved past the positions of the limiting structures 116, the bent arms 1063 can elastically urge the engagement ends 1064 toward an underside of the limiting structures 116. The obstructing positions of the limiting structures 116 can be thereby recovered, and the assembly of the second support portion and the first support portion 104 can be completed.

[0037] It is worth noting that the interference between the engagement ends 1064 and the limiting structures 116 can be effected in different directions. Figure 9 is a schematic view illustrating a variant embodiment for creating interference between the engagement ends 1064 and a variant construction of a limiting structure 117. In this embodiment, the engagement end 1064 can include a protrusion 1 064A projecting toward the sidewall 108B of the guide slot 108. The sidewall 108B can include a limiting structure 117 disposed above the uppermost groove 1 083A. The limiting structure 117 has the same function as the limiting structure 116 previously described, i:e., creating an obstruction against the engagement end 1064 to prevent the second support portion 105 from entirely disassembling from the first support portion 104.

After the engagement end 1064 has moved toward the central region of the pillar 107 out of the obstruction of the limiting structure 117, the second support portion 105 can be dismounted from the first support portion 104.

[0038] Aside the aforementioned contact interference between the engagement ends 1064 and the limiting structures 116, other constructions may be possible to prevent the second support portion 105 from entirely disengaging from the first support portion 104 during adjustment. Figure 10 is a schematic view illustrating another limiting structure adapted to prevent disengagement of the second support portion 105 from the first support portion 104. As shown, the pillar 107 of the second support portion 105 can include a restrain element 1075 that projects toward the sidewall 108B of the guide slot 108 at a location above the engagement end 1064. The sidewall 108B of the guide slot 108 can include a recessed pocket 1088 corresponding to the restrain element 1075. In one embodiment, the restrain element 1075 can be formed integral with the pillar 107 made of a plastic material. The restrain element 1075 can be disposed adjacent to the central region of the pillar 107, and have a resilient hook portion. When the second support portion 105 is adjusted vertically, the restrain element 1075 can slide up and down in the recessed pocket 1088 relative to the first support portion 104. In particular, as the engagement end 1064 is driven by the second support portion 105 and slides upward to reach or move past the uppermost groove I 083A, the restrain element 1075 can be brought to abut against a limiting structure provided at an uppermost region of the recessed pocket 1088 (e.g., shoulder surface 1088A). The second support portion 105 can be thereby stopped to prevent excessive course that may disengage the pillar 107 of the second support portion 105 from the guide slot 108 of the first support portion 104. For disassembling the second support portion 105 from the first support portion 104, the restrain element I 075 can be manually operated to disengage. from the interference of the surface 1088A. The amount of the restrain element 1075 can be adjusted according to the actual design requirement.

100391 The aforementioned embodiments can provide a latch mechanism that allows convenient adjustment, as well as easy disassembly and assembly of the seat backrest. Moreover, the constructions described herein can simplify the structure of the latch mechanism, and reduce the fabrication cost.

[00401 Figures 11 through 13 are schematic views illustrating the child safety seat 100 in three different configurations of use. In Figure 11, the child safety seat5lOO is shown in a first configuration where the backrest assembly 102 is assembled with the seat portion 101. The backrest assembly 102 can include the first support portion 104 and the second support portion 105. The first support portion 104 can be used as waist support, whereas the second support portion 105 can include the backrest region 109 and the headrest region 110. Moreover, the joining portions 102A of the backrest assembly 102 can be connected with the coupling element lOlA of the seat portion 101 (as better shown in Figure 13). With this construction, the backrest assembly 102 can be detachably assembled with the seat portion 101.

[0041] As shown in Figure 12, a plate 104B can be mounted between the lateral wings 1 04A of the first support portion 104. The plate 104 can have an inner side provided with an opening 104C through which the pillar 107 can be passed to mount through the guide slot 108. To provide a comfortable environment that allows the child to perform larger amplitudes of movement, the second support portion 105 can be disassembled from the first support portion 104, such that the pillar 107 and a portion of the latch mechanism 103 can be removed from the opening 1 04C. In addition, a cover portion of an outer fabric that wraps the seat portion 101 and the first support portion 104 (not shown) can be used to cover the opening 1 04C to provide comfortable seating and improve the outer appearance.

(0042] As shown in Figure 13, the first support portion 101 can also be detached from the seat portion 101, which can be used as a booster seat.

[0043] Realizations in accordance with the present invention therefore have been described only in the context of particular embodiments. These embodiments are* meant to be illustrative and not limiting. Many variations, modifications, additions, and improvements are possible. Accordingly, plural instances may be provided for components described herein as a single instance. Structures and functionality presented as discrete components in the exemplary configurations may be implemented as a combined structure or component. These and other variations, modifications, additions, and improvements may fall within the scope of the invention as defined in the claims that follow.

Claims

CLAIMS: 1. A child safety seat comprising: a seat portion; and a backrest assembly coupled with the seat portion, the backrest assembly including: a first support portion having a row of grooves; a second support portion movably assembled with the first support portion; and a latch mechanism including a latching element movably mounted with the second support portion and extending toward the first support portion, wherein the latching element includes at least one elastically deformable bent arm, and an engagement end at a distal end of the bent arm, wherein the latching element is operable to move along a first path to drive displacement of the bent arm and cause the engagement end to move along a second path to disengage or engage with one of the grooves, when the engagement end is disengaged from the groove, the latch mechanism is unlocked and the second support portion is adjustable relative to the first support portion, -when the engagement end is engaged with the groove, the latch mechanism locks the second support portion with the first support portion.
2. The child safety seat according to claim 1, wherein the first path is substantially perpendicular to the second path.
3. The child safety seat according to claim 1 or 2, wherein the second support portion includes a plurality of guide ribs in contact with the bent arm.
4. The child safety seat according to claim 1, 2 or 3, wherein the first support portion includes a guide slot, and the second support portion includes a pillar movably mounted through the guide slot.
5. The child safety seat according to claim 4, wherein the latch mechanism includes a spring having a first and a second end, the first end of the spring being connected with the latching element, the second end of the spring being connected with the second support portion, whereby the spring is adapted to bias the latching element to move along the first path.
6. The child safety seat according to claim 5, wherein the latching element has an anchor rib to which the first end of the spring is connected.
7. The child safety seat according to claim 6, wherein the latching element has a restrain slot, and the second suppOrt portion has a stud connected with the second end of the spring and movably engaged through the restrain slot for guiding movements of the latching element relative to the second support portion.
8. The child safety seat according to claim 7, wherein the stud is mounted with a restrain screw adapted to prevent disengagement of the latching element from the stud.
9. The child safety seat according to any preceding claim, wherein a rear of the second support portion includes a channel along which the latching element is movably mounted for vertically up and down movements, the channel having two side edges provided with restrain ribs adapted to prevent lateral disengagement of the latching element from the channel.
10. The child safety seat according to any preceding claim, wherein the first support structure includes a limiting structure adapted to prevent disengagement of the second support portion from the first support portion by abutting against the engagement end of the latching element as the second support portion is adjustably moved relative to the first support portion.
11. The child safety seat according to any preceding claim, wherein the second support portion includes a movable stop element against which the latching element comes into abutment to limit an upward course of the latching element, the stop element being operable to disengage from the abutment with the latching element for allowing further upward movement of the latching element when the second support portion is removed from the first support portion.
12. The child safety seat according to claim 11, wherein the stop element is formed as a resilient tab mounted with the second support portion, and the latching element includes an actuator portion that comes in abutment against the resilient tab when the latching element moves upward, the latch mechanism being unlocked when the resilient tab is operated to remove the abutment against the actuator portion.
13. The child safety seat according to claim 10, wherein the second support portion includes at least one restrain element, when the second support is adjusted upward relative to the first support portion, the restrain element is adapted to abut against the limiting structure to prevent separation of the second support portion from the first support portion.
14. The child safety seat according to claim 10, wherein the limiting structure has an angled surface that is adapted to push the engagement end away from the limiting structure when the latching element is moving downward.
The child safety seat according to claim 1, wherein the second support portion includes a restrain element adapted to abut against a shoulder surface provided in the first support portion to prevent separation of the second support portion from the first support pOrtion.
16. The child safety seat according to any preceding claim, wherein the second support portion includes a headrest region and a backrest region.
17. The child safety seat according to claim 16, wherein the headrest region has two sides provided with first lateral wings, and the backrest region has two sides provided with second lateral wings.
18. The child safety seat according to claim 17, wherein the first support portion has two sides provided third lateral wings.
19. The child safety seat according to any preceding claim, wherein the first support portion is detachably mounted with the seat portion.
20. The child safety seat according to claim 19, wherein the first support portion includes at least a joining portion, and the seat portion includes at least one coupling element adapted to connect with the joining portion.
21. The child safety seat according to claim 20, wherein the coupling element is a C-shaped clamp, and the joining portion is a rod.
22. The child safety seat according to any preceding claim, wherein the first support portion is a waist support.
23. A child safety seat comprising: a seat portion; and a backrest assembly including: a first support portion detachably connected with the seat portion; a second support portion detachably assembled with the first support portion; and a latch mechanism assembled between the first and the second support portions, the latch mechanism having a locked state for holding the second support portion in place relative to the first support portion, and an unlocked state allowing adjustment of the second support portion relative to the first support portion.
24. The child safety seat according to claim 23, wherein the first support portion includes at least a joining portion, and the seat portion includes at least one coupling element adapted to detachably mount with the joining portion.
25. The child safety seat according to claim 24, wherein the coupling element is a C-shaped clamp, and the joining portion is a rod.
26. The child safety seat according to claim 23, 24 or 25, wherein the first support portion is a waist support.
27. The child safety seat according to claim 23, 24, 25 or 26, wherein the second support portion includes a headrest region.
28. A child safety seat substantially as hereinbefore described with reference to the accompanying drawings.