Stroller with foldable structure

A stroller comprising:

• 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;
• wherein:
• each of the support units includes:
• a connecting piece;
• a rear leg having a first end mounted on the connecting piece;
• and
• a rear wheel mounted on a second end of the rear leg;
• the connecting piece of each of the support units is provided with two first connecting grooves and a second connecting groove;
• the outer frame unit includes:
• an upper frame having two opposite ends each pivotally connected with the respective first connecting groove of each of the support units;
• a lower frame having two opposite ends each pivotally connected with the respective first connecting groove of each of the support units;
• a side frame pivotally connected with the upper frame;
• and
• a front wheel mounted on the lower frame;
• each of the linking units includes a connecting block mounted on the rear leg of the respective support unit;
• an upper curved lever mounted between the connecting block and the upper frame of the outer frame unit;
• a lower curved lever mounted between the connecting block and the lower frame of the outer frame unit;
• and
• a support bar connected with the connecting block;
• the connecting block of each of the linking units is provided with a mounting hole, two first connecting recesses, a second connecting recess and a connecting portion;
• the mounting hole of each of the linking units is slidably mounted on the rear leg of the respective support unit;
• the upper curved lever of each of the linking units has a first end pivotally connected with the respective first connecting recess of the connecting block and a second end pivotally connected with the respective end of the upper frame of the outer frame unit;
• the lower curved lever of each of the linking units has a first end pivotally connected with the respective first connecting recess of the connecting block and a second end pivotally connected with the respective end of the lower frame of the outer frame unit;
• the support bar of each of the linking units is connected with the connecting portion of the connecting block;
• the cross connection unit includes:
• two oblique levers intersecting each other;
• and
• two rotation members each mounted on the respective oblique lever;
• the rotation members of the cross connection unit are pivotally connected with each other;
• each of the oblique levers of the cross connection unit has a first end pivotally connected with the second connecting groove of the respective support unit and a second end pivotally connected with the second connecting recess of the respective linking unit;
• the positioning and folding unit includes a folding base, a compression spring, a control cover, two first pins, a second pin, two folding bars, and two positioning protrusions;
• the folding base of the positioning and folding unit is provided with a receiving chamber, two elongate slots and a mounting channel;
• the control cover of the positioning and folding unit is movably mounted on the folding base;
• each of the first pins of the positioning and folding unit is extended through the control cover and is slidably mounted in the respective elongate slot of the folding base;
• the second pin of the positioning and folding unit is extended through the control cover and is slidably mounted in the receiving chamber of the folding base;
• the compression spring of the positioning and folding unit is mounted in the receiving chamber of the folding base and is biased between the folding base and the second pin;
• each of the folding bars of the positioning and folding unit has a first end pivotally mounted in the mounting channel of the folding base and a second end pivotally connected with the connecting block of the respective linking unit;
• each of the positioning protrusions of the positioning and folding unit is formed on the first end of the respective folding bar and is provided with a positioning groove and a plurality of engaging teeth;
• the positioning groove of each of the positioning protrusions is detachably locked onto the respective first pin;
• and
• the engaging teeth of the positioning protrusions mesh with each other.