Abstract: A stroller includes an outer frame unit, two support units connected with the outer frame unit, two linking units connected with the outer frame unit and the support units, a cross connection unit mounted between the support units and the linking units, and a positioning and folding unit mounted between the support units. Thus, the positioning and folding unit is operated to expand and collapse the stroller.

Abstract: A carrier for an infant car seat includes a lower support unit, two pairs of position adjusting units connected with the lower support unit, two pairs of angle adjusting units connected with the position adjusting units, and a pair of upper support bars connected with the angle adjusting units. An infant car seat is placed and supported between the upper support bars. Thus, the carrier is used to fix and support the infant car seat and can be placed indoors and outdoors. In addition, the carrier can be directly taken out of the car to support the infant car seat, so that the user can place and carry the infant car seat easily and conveniently.

Abstract: A foldable bottom bracket device for a stroller includes a base unit having a bottom bracket, a support unit pivotally connected with the base unit, and a locking unit rotatably mounted on the base unit and detachably locked onto the support unit. The support unit includes two support rods each pivotally connected with the bottom bracket, and two limit rods each pivotally connected with the bottom bracket. The locking unit includes a rotation cover rotatably mounted on the bottom bracket and having two locking hooks detachably locked onto the limit rods respectively. Thus, the user only needs to rotate the rotation cover to detach the locking hooks from the limit rods to release the limit rods from the bottom bracket to unlock the support unit so that the bottom bracket device is unlocked and folded easily and quickly.