Abstract:
A child booster seat includes a seat base, and an armrest support coupled to the seat base and formed with an installation space that opens upward. The armrest support has a wall confronting the installation space and formed with a plurality of restraining parts located at different heights of the armrest support. The child booster seat further includes an armrest assembly including a latching component having a tongue board that extends into the installation space and that is movable vertically within the installation space and a stop piece that projects from the tongue board for engaging selectively the restraining parts, and an armrest component coupled to the tongue board and vertically co-movable with the tongue board relative to the armrest support.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority of U.S. Provisional Application No. 61/210,997, filed on Mar. 25, 2009. This application also claims priority to Chinese Application No. 200910179569.8, filed on Sep. 30, 2009. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to a child booster seat, more particularly to a child booster seat with a height-adjustable armrest. 
     2. Description of the Related Art 
     A child booster seat may be used to raise the height of a child to assist with feeding the child. One example of a child booster seat design is illustrated in U.S. Pat. No. 7,104,603. In the prior art, the armrest of the child booster is not easy to operate while a caregiver wants to adjust the height of the armrest for a child seating on the seat. Accordingly, the design and operation of a child booster seat may still be improved. 
     SUMMARY OF THE INVENTION 
     The object of the present invention is to provide a child booster seat with a height-adjustable armrest that is relatively easy to adjust. 
     According to the present invention, a child booster seat includes a seat base, and an armrest support coupled to the seat base and formed with an installation space that opens upward. The armrest support has a wall confronting the installation space and formed with a plurality of restraining parts located at different heights of the armrest support. The child booster seat further includes an armrest assembly that includes a latching component, which includes a tongue board that extends into the installation space and that is movable vertically within the installation space and a stop piece that projects from the tongue board for engaging selectively the restraining parts. 
     The armrest assembly further includes an armrest component that is coupled to the tongue board and that is vertically co-movable with the tongue board relative to the armrest support. The armrest component is supported at a selected height of the armrest support when the stop piece engages one of the restraining parts. The tongue board is operable to move the stop piece relative to the armrest component for disengaging the restraining parts and permitting height adjustment of the armrest assembly relative to the armrest support. 
     Preferably, the armrest component is formed with a slot that opens upward and an access opening in spatial communication with the slot. The tongue board is received in the slot, and the stop piece protrudes through the access opening when the stop piece engages one of the restraining parts-Preferably, the armrest assembly further includes a pressing component that is installed on the armrest component and that has a pressing side and a pushing side. The pushing side abuts against the tongue board of the latching component such that a horizontal force on the pressing side is transmitted to the tongue board to move the stop piece relative to the armrest component for disengaging the restraining parts. 
     Preferably, the pressing component is located at a height position between the stop piece and a coupling junction between the tongue board and the armrest component. 
     Preferably, the child booster seat further includes a position limiting mechanism provided on the armrest support and the armrest component for limiting vertical movement of the armrest component relative to the armrest support. 
     Preferably, the position limiting mechanism includes a hole-defining portion that is provided on one of the wall of the armrest support and the armrest component and that defines a position limiting hole, and a position limiting block that is provided on the other one of the wall of the armrest support and the armrest component and that extends into the position limiting hole to limit the vertical movement of the armrest component relative to the armrest support. 
     Preferably, the armrest assembly further includes a return spring located between the tongue board and the armrest component for biasing the tongue board to move the stop piece toward the restraining parts. 
     Preferably, the tongue board has one end that is opposite to the stop piece and that is pivotable relative to the armrest component about a horizontal axis. 
     Preferably, one of the tongue board and the armrest component is formed with an indentation, and the other one of the tongue board and the armrest component is formed with a protrusion. The return spring has a first spring end sleeved on the protrusion and a second spring end received in the indentation. 
     Preferably, the restraining parts include a first stop opening and a second stop opening that are formed in the armrest support and that are vertically spaced apart from each other. 
     Preferably, the restraining parts include vertically spaced apart upper and lower arc edges on the wall of the armrest support, and the stop piece has a peripheral contour conforming with those of the upper and lower arc edges. Preferably, the armrest component includes a vertical board portion that is formed with the access opening, and a horizontal board portion that is connected to a top end of the vertical board portion and that is formed with the slot. The tongue board has a top portion that is connected to the horizontal board portion, and an extension portion that extends downwardly from the top portion, that is received in the slot, and that is formed with the stop piece. 
     Preferably, the position limiting mechanism includes a limit block protruding from the vertical board portion, and a stop block protruding from the armrest support into the installation space and vertically aligned with the limit block. Engagement between the limit block and the stop block prevents the armrest assembly from separating from the armrest support when the armrest assembly is moved vertically upward relative to the armrest support. 
     Preferably, the extension portion is deformable by a horizontal force to move the stop piece relative to the armrest component for disengaging the restraining parts. 
     Preferably, the extension portion is resilient and biases the stop piece toward the restraining parts. 
     In the present invention, the armrest assembly can be disengaged from the armrest support to allow the armrest assembly to be adjusted to a desired height. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Other features and advantages of the invention will become apparent in the following detailed description with reference to the accompanying drawings, of which: 
         FIG. 1  is a perspective view of a child booster seat, according to a first embodiment; 
         FIG. 2  is another perspective view illustrating the child booster seat with a height adjustable armrest assembly, according to the first embodiment; 
         FIG. 3  is an exploded perspective view illustrating an armrest support and an armrest assembly, according to the first embodiment; 
         FIG. 4  is an exploded perspective view illustrating the armrest assembly, according to the first embodiment; 
         FIG. 5  is a fragmentary perspective view illustrating a raised part of an armrest component, according to the first embodiment; 
         FIG. 6  is a perspective view illustrating an indentation of a latching component of the armrest assembly, according to the first embodiment; 
         FIG. 7  is a fragmentary schematic sectional view illustrating a stop piece of the latching component in a first stop opening, according to the first embodiment; 
         FIG. 8  is a fragmentary schematic sectional view illustrating the stop piece separated from the first stop opening, according to the first embodiment; 
         FIG. 9  is a fragmentary schematic sectional view illustrating the stop piece of the latching component that is moved toward a second stop opening, according to the first embodiment; 
         FIG. 10  is a fragmentary schematic sectional view illustrating the stop piece in the second stop opening, according to the first embodiment; 
         FIG. 11  is a schematic side view of a child booster seat, according to a second embodiment; 
         FIG. 12  is another schematic side view illustrating the child booster seat with a height adjustable armrest assembly, according to the second embodiment; 
         FIG. 13  is an assembled perspective view illustrating the armrest assembly of the second preferred embodiment; 
         FIG. 14  is an exploded perspective view illustrating an armrest component, a latching component, and a pressing component, according to the second embodiment; 
         FIG. 15  is a fragmentary partly cutaway perspective view illustrating a position limiting block of an armrest component of the armrest assembly and a stop piece of a latching component, according to the second embodiment; 
         FIG. 16  is a fragmentary schematic sectional view illustrating the stop piece located at a lower arc edge, according to the second embodiment; and 
         FIG. 17  is a fragmentary schematic sectional view illustrating the stop piece located at an upper arc edge, according to the second embodiment. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     Referring to  FIGS. 1 ,  2  and  3 , the first preferred embodiment of a child booster seat  101  according to this invention includes a seat base  2 , a pair of armrest supports  3 , a pair of armrest assemblies  4 , and a pair of armrest support housings  7 . The armrest support housings  7  are located at two sides of the seat base  2  and are integrally formed with the seat base  2 . Each of the armrest support housings  7  is formed with a receiving slot  71 . The two armrest supports  3  are each disposed in one of the receiving slots  71  of the armrest support housings  7 . As shown in  FIG. 3 , each of the armrest supports  3  is fixed in one of the armrest support housings  7  that are connected to the sides of the seat base  2 . An armrest assembly  4  is disposed in each armrest support  3 . The armrest assembly  4  is capable of moving upwards and downwards relative to the armrest support  3  to adjust the height of the armrest assembly  4 . 
     Referring to  FIG. 3 , each of the armrest supports  3  includes a support body  31  formed with an installation space  32 , a pair of first stop openings  331 , a pair of second stop openings  332 , and a position limiting hole  34 . The support body  31  is fitted in the receiving slot  71 . The top of the support body  31  is provided with a pair of fixing parts  311  to fasten the armrest supports  3  in the receiving slots  71  of the armrest support housings  7  with the use of screws (not shown). The installation space  32  is formed between a pair of confronting lateral walls of the support body  31  and has an upwardly facing opening. The first stop openings  331  are spaced apart from each other and are formed on left and right sides of one of the lateral walls of the support body  31 . The second stop openings  332  are also spaced apart from each other, are formed on left and right sides of the one of the lateral walls, and are spaced apart from and disposed above the first stop openings  331 , respectively. The position limiting hole  34  is located between the first stop openings  331  and has a vertical length larger than the distance between the top edges of the first stop openings  331  and the bottom edges of the second stop openings  332 . 
     Referring to  FIGS. 3 and 4 , each of the armrest assemblies  4  includes an armrest component  41 , a latching component  42 , a pressing component  43 , a return spring  44 , a pivot axle  45 , and an armrest cover  46 . The armrest component  41  includes an armrest component body  411  that can be installed in and displaced up and down within the installation space  32 . The armrest component  41  has an upwardly opening slot  412  formed in the armrest component body  411  and a pair of access openings  413  formed on a lateral side of the armrest component body  411 . The access openings  413  are capable of being brought into alignment with the first stop openings  331  or the second stop openings  332  when the armrest component body  411  is displaced upwards and downwards in the slot  412 . 
     The armrest component  41  further has a position limiting block  414  protruding from the armrest component body  411  and extending into the position limiting hole  34 , such that, when the armrest component  41  moves upward to the extent that the position limiting block  414  abuts against the top edge of the position limiting hole  34 , the armrest component  41  is stopped from further upward movement and is prevented from separating from the corresponding armrest support  3 . 
     Moreover, the armrest component  41  further includes a pair of pivot base parts  415  that are located at the top of the armrest component body  411 . The pivot base parts  415  are preferably adjacent to the upward opening of the slot  412  and are spaced apart from each other. The armrest component  41  further has a receiving hole  416  for the pressing component  43  to extend through. The top of the armrest component  41  is formed to couple with the armrest cover  46  to cover the pivot base parts  415 , the purpose of which will be further described below. 
     The latching component  42  includes a tongue board  421  with a forked bottom section and a top edge configured with an axle hole  422 , and a pair of protruding stop pieces  423  at the bottom of the tongue board  421 . The tongue board  421  is installed between the pivot base parts  415  of the armrest component  41 , and the pivot axle  45  extends through the pivot base parts  415  and the axle hole  422  formed on the top edge of the tongue board  421 , such that the latching component  42  can pivot about a horizontal axis with respect to the armrest component  41 . 
     The stop pieces  923  may pass through the first stop openings  331  or the second stop openings  332  via the access openings  413 . By extending the stop pieces  423  through the access openings  413  and either the first stop openings  331  or the second stop openings  332 , the armrest assembly  4  is securely positioned with respect to the corresponding armrest support  3 . 
     The pressing component  43  extends through the receiving hole  416  of the armrest component  91  and abuts against the tongue board  421  of the latching component  42 . The pressing component  43  has a pressing side  431  accessible from the respective one of the armrest supports  3 , and a pushing side  432  extending from the pressing side  431 . The pushing side  432  contacts the tongue board  421  of the latching component  42 , such that a horizontal force exerted on the pressing side  432  can be relayed to the tongue board  421 . This enables the stop pieces  423  to be moved away from the first stop openings  331  or the second stop openings  332 , which allows adjustment of the position or height of the armrest assembly  4  relative to the corresponding armrest support  3 . 
     In the embodiment, the tongue board  421  of the latching component  42  has an outer side formed with a protrusion  424  to abut against the pressing component  43 . In addition, as illustrated in  FIG. 3 , the pressing component  43  is positioned by the receiving hole  416  of the armrest component  41  such that the pressing component  43  contacts the latching component  42  at a height position of the tongue board  421  between the axle hole  422  and the stop pieces  423 . 
     Referring to  FIGS. 3 ,  5  and  6 , the return spring  44  is located between the tongue board  421  of the latching component  42  and the armrest component  41 . In the embodiment, the tongue board  421  of the latching component  42  has a face with an indentation  425 , and the armrest component  41  has a protrusion  417  extending from an inner lateral wall. One end of the return spring  44  is sleeved on the protrusion  417 , and the other end of the return spring  44  is received in the indentation  425 . In such a manner, the return spring  44  biases the latching component  42  toward the lateral wall of the armrest component body  411  of the armrest component  41  that is formed with the access opening  413 . The return spring  44  may be mounted such that it applies a horizontal return force when it is compressed or expanded. In other words, the above assembly applies a force to maintain the insertion of each stop piece  423  of the latching component  42  through the corresponding access opening  413  and either the corresponding first stop opening  331  or the corresponding second stop opening  332  to hold a secure position. 
     The pivot axle  45  has a first section  451  and a second section  452 . Because the tongue board  421  of the latching component  42  is located between the corresponding pivot base parts  415 , and the axle hole  422  formed on the top edge of the tongue board  421  may be aligned with the pivot base parts  415 , by extending each of the first section  451  and the second section  432  of the pivot axle  45  through the respective pivot base part  415  and the axle hole  422 , the latching component  42  is connected pivotably to the armrest component  41  and is capable of being displaced in the slot  412  by being rotated about the pivot axle  45 . 
     Referring to  FIGS. 7 to 10 , when a user wants to adjust the armrest assembly  4  higher, by depressing the pressing component  43 , the tongue board  421  of the latching component  42  moves away from the first stop openings  331  and compresses the return spring  44 . This movement of the tongue board  421  separates the stop pieces  423  located at the bottom end of the tongue board  421  from the first stop openings  331 , thereby disengaging the fastening between the armrest assembly  4  and the armrest support  3 . The user may then pull the armrest assembly  4  upwards until the stop pieces  423  reach the second stop openings  332 . 
     After the external force on the pressing component  43  is released, the return force of the return spring pushes the tongue board  421  of the latching component  92  return. The movement of the tongue board  421  causes a linked movement of the stop pieces  423 , extending the stop pieces  423  through the access openings  413  and into the second stop openings  332 , thereby securely positioning the armrest assembly  4  and the corresponding armrest support  3 . 
     On the other hand, when adjusting the armrest assembly  4  to a lower height, the pressing component  43  may be depressed to disengage the stop pieces  423  from the second stop openings  332 . The user can then move the armrest assembly  4  downwards until the stop pieces  423  reach the first stop openings  331 . At this time, the stop pieces  423  can be extended through the access openings  413  and into the first stop openings  331 , again securely positioning the armrest assembly  4  and the corresponding armrest support  3 . The pressing component  43  may be released when the stop pieces  423  are aligned with the first stop openings  331 , or in other embodiments, prior to the time the stop pieces  423  are moved into alignment with the first stop openings  331 . 
     The tongue board  421  can be displaced by the return spring  44  or the pressing component  43  such that the tongue board  421  is pivoted about a horizontal axis with respect to the armrest component  41 . The movement of the tongue board  421  of the latching component  42  causes a linked movement of the stop pieces  423 . In other embodiments, the tongue board  421  may be pushed or pulled through direct contact by a user to displace the tongue board  421  and to cause a linked movement of the stop pieces  423 . The direct contact may be made through the receiving hole  416  or through an open space of the armrest support  3 . Alternatively, the tongue board  421  may include a protrusion that may be pulled or rotated to cause the tongue board  421  to be displaced. 
     The linked movement of the stop pieces  423  may cause them to be extended into or retracted from the access openings  413  and engaged or disengaged with the first stop openings  331  or the second stop openings  332 . In such a manner, the armrest assembly  4  can be secured to or disengaged from the corresponding armrest support  3 , allowing the height of the armrest assembly  4  to be adjusted to provide a comfortable resting position for arms of a child. Although in the embodiment, the first stop openings  331  and the second stop openings  332  are used to adjust the height of the armrest assembly  4 , additional or fewer stop openings may be provided for height adjustment of the armrest assembly  4  in accordance with practical requirements. 
     In the embodiment, the first stop openings  331  and the second stop openings  332  act as restraining parts for holding the armrest assembly  4  and the armrest support  3  in a fixed relative vertical position when the stop pieces  423  are extended through the access openings  413  to engage a restraining part, such as the first stop openings  331  or the second stop openings  332 . In other embodiments, the restraining parts may include protrusions, openings, ridges, interlocking, or other components that interact with the stop pieces  423  and that may be used to restrict relative vertical movement between the armrest assembly  4  and the armrest support  3 . For example, in other embodiments, each stop piece  423  may include an opening that receives a corresponding protruding restraining part of the armrest support  3 . 
     Referring to  FIGS. 11 and 12 , the second preferred embodiment of a child booster seat  102  according to this invention includes a seat base  2 , a pair of armrest supports  5 , and a pair of armrest assemblies  6  (due to the viewing angle, only one armrest support  5  and one armrest assembly  6  are shown in the Figures). In the embodiment, the armrest assemblies  6  are adjustable between two different height positions. As shown in  FIGS. 11 and 12 , the different height positions of the armrest assemblies  6  are a comparatively lower height position and a comparatively higher height position. In the embodiment, the armrest supports  5  are located at two sides of the seat base  2  and are integrally formed with the seat base  2 . The armrest assemblies  6  are installed in the armrest supports  5 , respectively. The armrest assemblies  6  may be moved upwards and downwards relative to the respective armrest supports  5  to adjust the height of the armrest assemblies  6 . 
     Referring to  FIGS. 12 ,  15  and  16 , each of the armrest supports  5  includes a seat body  51  formed with an installation space  52 , a lower arc edge  531 , an upper arc edge  532 , and a pair of stop blocks  54 . The installation space  52  is formed with an upwardly facing opening in the seat body  51  and is confined between a pair of confronting lateral walls of the seat body  51 . The upper arc edge  532  and the lower arc edge  531  are formed at respective higher and lower locations of one of the lateral walls of the seat body  51  of the armrest support  5 . In the embodiment, the lower arc edge  531  is formed by the upper boundary of an opening in the one of the lateral walls of the seat body  51 , and the upper arc edge  532  is formed by a lower boundary of an opening in the one of the lateral walls of the seat body  51 , with the upper are edge  532  being located above the lower arc edge  531 . The upper arc edge  532  and the lower arc edge  531  are located approximately in the middle of the one of the lateral walls between the left and right sides of the one of the lateral walls. 
     The stop blocks  54  protrude from an inner wall of the seat body  51  and into the installation space  52 . In the embodiment, the stop blocks  54  are located such that the upper arc edge  532  and the lower arc edge  531  are formed between the left and right positions of the stop blocks  54  on the inner well of the seat body  51 . The stop blocks  54  are located approximately at the height position of the upper arc edge  532 . In other embodiments, one or more stop blocks  54  may be used, and the stop blocks  54  may be formed by a ledge, an opening, or other surface that may oppose upwards travel of a corresponding surface or object. In addition, the stop blocks  54  may be located above or below the height position of the upper arc edge  532 . 
     Referring to  FIGS. 13 and 14 , each of the armrest assemblies  6  includes an armrest component  61 , a latching component  62 , and a pressing component  63 . The armrest component  61  includes a vertical board portion  610  formed with an access opening  612  and a receiving hole  614 . In the embodiment, the vertical board portion  610  is installed in the installation space  52  of the seat body  51  such that the armrest assembly  6  may be moved upwards and downwards. 
     The access opening  612  is formed at an area between the left and right sides of the vertical board portion  610  and below the receiving hole  614 . The access opening  612  is further aligned vertically with the upper arc edge  532  and the lower arc edge  531 . The vertical board portion  610  includes a raised platform  616 , which is located at the top of the access opening  612  and which is formed with the receiving hole  614 . The pressing component  63  passes through the receiving hole  614 . The raised platform  616  protrudes from a wall of the vertical board portion  610  such that a lower boundary of the raised platform  616  may conform to and abut against the upper arc edge  532  when the armrest assembly  6  is at a lowered position. The lower boundary of the raised platform  616  may limit the downward travel of the armrest assembly  6  when the armrest assembly  6  is installed in the installation space  52  of the seat body  51 . 
     The armrest component  61  also includes a horizontal board portion  611  connected to a top of the vertical board portion  610 . A slot  613  is formed in the middle of the horizontal board portion  611  that allows the latching component  62  to be inserted and installed in the slot  613 . The horizontal board portion  611  may conform to and abut against an upper end of the seat body  51  to limit downward travel of the armrest assembly  6  when the latter is installed in the installation space  52  of the seat body  51 . 
     Moreover, as shown in  FIGS. 14 and 15 , the armrest component  61  further includes a pair of position limiting blocks  615 . The position limiting blocks  615  are formed by indenting a side of the vertical board portion  610  to create protrusions into the installation space  52  and adjacent to the lateral wall with the stop blocks  54 . The position limiting blocks  615  are located on left and right sides of the vertical board portion  610  with the access opening  612  located between the position limiting blocks  615 . The position limiting blocks  615  are located approximately at a height position of the bottom edge of the access opening  612 . The position limiting blocks  615  protrude from the vertical board portion  610  to align with the stop blocks  54 . 
     When the armrest assembly  6  is moved upwards, the position limiting blocks  615  on the vertical board portion  610  are moved upwards until they abut against the stop blocks  54  on the seat body  51 , thereby preventing separation of the armrest assembly  6  from the armrest support  5 . In other embodiments, one or more position limiting blocks  615  may be used, and the position limiting blocks  615  may be installed at the same height, above, or below the bottom edge of the access opening  612 . 
     Referring to  FIGS. 13 ,  14  and  16 , the latching component  62  passes through and is installed in the slot  613  of the armrest component  61 . The latching component  62  includes a tongue board  621  that extends along the vertical board portion  610 , both horizontally across and downwards next to the vertical board portion  610 . The tongue board  621  has a top portion  6211  assembled to the horizontal board portion  611  and an extension portion  6212  to be inserted into and mounted within the slot  613 . In such a manner, the latching component  62  is connected to the armrest component  61 . 
     The latching component  62  further has a stop piece  623  protruding from the bottom part of the extension portion  6212  for extending through the access opening  612  and abutting against either the lower arc edge  531  and the upper arc edge  532 . The stop piece  623  also takes an arc shape and is configured to contact closely with the lower arc edge  531  or the upper arc edge  532 . As such, by virtue of the stop piece  623  extending through the access opening  612  and contacting with either the lower arc edge  531  or the upper arc edge  532 , the armrest assembly  6  may be securely supported on the corresponding armrest support  5 . In the embodiment, the stop piece  623  is large enough to provide adequate support for a user&#39;s arm, and the top portion  6211  is shaped like the armrest cover  46  in the first preferred embodiment. 
     Referring to  FIGS. 14 and 16 , the pressing component  63  extends through the receiving hole  614  of the armrest component  61  and abuts against the tongue board  621  of the latching component  62 . The pressing component  63  has a pressing side  631  and a pushing side  632 . The pressing side  631  is accessible outside of a respective armrest support  5  to allow the pressing component  63  to be pressed. The pushing side  632  abuts against the tongue board  621  of the latching component  62 , such that a horizontal force exerted on the pressing side  631  can be relayed to the tongue board  621 . The tongue board  621  can then separate the stop piece  623  from the interference position with the upper arc edge  532  or the lower arc edge  531 , thus releasing the armrest assembly  6  from a secured position to allow the armrest assembly  6  to be moved up or down in the installation space  52 . The pressing component  63  contacts the tongue board  621  at a location between the stop piece  623  and the connection between the tongue board  621  and the armrest component  61 . 
     By fixing the top portion  6211  to the horizontal board portion  611 , the extension portion  6212  is suspended downwards. By pushing the pressing component  63 , the extension portion  6212  may be moved horizontally and the stop piece  623  may be separated with the upper arc edge  532  or the lower arc edge  531 . Due to a bending moment on the tongue board  621 , which caused by the pushing at the pressing component  63  and a distance between the pressing component  63  and the fixed end of the top portion  6211 , and the resiliency of the material from which the extension portion  6212  is formed, the extension portion  6212  has an inherent return force. Hence, when the pressing component  63  is no longer depressed, the extension portion  6212  is restored to its original position. In other words, the resiliency of the extension portion  6212  biases the stop piece  623  towards the lower arc edge  531  or the upper arc edge  532 . A return spring may also be installed between the extension portion  6212  and the pressing component  63  to increase the horizontal return force to bring the pressing component  63  back to its former position. 
     Referring to  FIGS. 16 and 17 , when a user wishes to adjust the armrest assembly  6  higher, by depressing the pressing component  63 , the extension portion  6212  is moved away from the lateral side that has the lower arc edge  531  and the upper arc edge  532 . When the extension portion  6212  is moved, the connected stop piece  623  is also moved away from the access opening  612  and the lower arc edge  531 , which releases the armrest assembly  6  from the secured position and allows the armrest assembly  6  to be pulled upward until the stop piece  623  moves above the upper arc edge  532 . 
     At this time, the pressing component  63  may be released such that the horizontal return force of the extension portion  6212  moves the extension portion  6212  of the latching component  62  towards the lateral side that has the lower arc edge  531  and the upper arc edge  532 . The pressing component  63  is also moved outwards in a connected movement due to contact between the pressing component  63  and the extension portion  6212 . The movement of the extension portion  6212  causes a connected movement of the stop piece  623 , extending the stop piece  623  through the corresponding access opening  612  and joining the stop piece  623  with the corresponding upper arc edge  532 . The lateral wall of the seat body  51  that forms the upper arc edge  532  then supports the armrest assembly  6 . The dimensions of the stop piece  623  and the thickness of the lateral wall that forms the upper arc edge  532  are large enough to stably support a user&#39;s arm resting on the armrest assembly  6 . Accordingly, relative downward movement of the armrest assembly  6  with respect to the armrest support  5  is restricted, and the armrest assembly  6  is securely positioned at a raised position with respect to the armrest support  5 . 
     When a user wishes to adjust the armrest assembly  6  lower, by depressing the pressing component  63 , the stop piece  623  may be disengaged from the upper arc edge  532 , releasing the armrest assembly  6  from the securely positioned state. The armrest assembly  6  can then be moved downwards until the stop piece  623  is moved below the lower arc edge  531 . At this time, the stop piece  623  can be extended through the access opening  612  to join the stop piece  623  with the lower arc edge  531 , which restricts relative upward movement of the armrest assembly  6  with respect to the armrest support  5 . In addition, the horizontal board portion  611  abuts against the top of the seat body  51  of the armrest support  5 . In other words, the top of the seat body  51  of the armrest support  5  supports the armrest assembly  6 , thereby allowing the armrest assembly  6  to securely support a user&#39;s arm resting thereon. Accordingly, the armrest assembly  6  may be securely positioned at a lowered position when the stop piece  623  passes through the access opening  612  and engages the lower arc edge  531 . The stability of support in either the raised or lowered position is therefore assured. 
     The extension portion  6212  of the latching component  62  may be displaced by either the horizontal return force of the extension portion  6212  or a force transmitted by the pressing component  63 . In other embodiments, the extension portion  6212  may be pushed or pulled through direct contact by a user to displace the extension portion  6212  and to cause a linked movement of the stop piece  623 . The direct contact may be made through the receiving hole  614  or through an open space of the armrest support  5 . Alternatively, the extension portion  6212  may include a protrusion that may be pulled or operated to cause the extension portion  6212  to be displaced. 
     In the embodiment, the upper arc edge  532  and the lower arc edge  531  act as restraining parts for holding the armrest assembly  6  and the armrest support  5  in a fixed relative vertical position when the stop piece  623  is extended through the access opening  612  to engage a restraining part, such as the upper arc edge  532  or the lower arc edge  531 . In other embodiments, the restraining parts may include protrusions, openings, ridges, interlocking, or other components that interact with the stop piece  623  and that restrict relative vertical movement between the armrest assembly  6  and the armrest support  5 . For example, in other embodiments, the stop piece  623  may have an opening that receives a corresponding protruding restraining part of the armrest support  5 . 
     To sum up, through a simple operation that involves pressing the pressing component  43 ,  63 , the child booster seat  101 ,  102  allows the armrest assembly  4 ,  6  to be released from the securely positioned state relative to the armrest support  3 ,  5  and adjusted to a desired height. 
     While various embodiments have been described in connection with particular examples, it should be understood that the invention is not limited to the disclosed embodiments but is intended to cover various arrangements included within the spirit and scope of the broadest interpretation so as to encompass all such modifications and equivalent arrangements.