Toolbox with a stacking function

1. A toolbox having

a body being a casing and having

a top face having four corners;

a bottom face being parallel with the top face of the body and having four corners respectively aligning with the four corners of the top face of the body;

two opposite sidewalls formed with the top face of the body and the bottom face of the body and facing each other;

four positioning segments formed on and protruding from the top face of the body respectively at the four corners of the top face of the body;

four locating segments formed on and protruding from the bottom face of the body respectively at the corners of the bottom face of the body, respectively aligning with the four positioning segments, and when two toolboxes stacked up with each other, the four locating segments of the body of an uppermost toolbox respectively engaging with the four positioning segments of the body of a lowermost toolbox;

at least two mounting recesses formed in the two opposite sidewalls of the body adjacent to the bottom face of the body, and each one of the at least two mounting recesses having

two inner opposite sides being perpendicular to the bottom face of the body and facing each other; and

two pivot holes being square, respectively formed in the two inner opposite sides of the mounting recess near the bottom face of the body and aligning with each other; and

at least two holding recesses formed in the two opposite sidewalls of the body adjacent to the top face of the body above the at least two mounting recesses, and each one of the at least two holding recesses having

a top outer side formed on and protruding downwardly from the top face of the body between two adjacent positioning segments; and

two engaging holes formed through the top outer side of the holding recess at an interval and communicating with the holding recess;

at least two connecting elements detachably and pivotally connected to the body in the at least two mounting recesses, and each one of the at least two connecting elements having

an inner side facing a corresponding mounting recess of the body;

an outer side;

a top end;

a bottom end;

two opposite sides respectively facing the two inner opposite sides of the corresponding mounting recess;

a connecting rod transversally formed on and protruding from the outer side of the connecting element at the bottom end of the connecting element and having two inserting ends respectively extending out of the two opposite sides of the connecting element, respectively inserted into the two pivot holes of the corresponding mounting recess, and each one of the inserting ends having a cross section corresponding to a shape of a corresponding pivot hole to enable the connecting rod to turn relative to the pivot holes of the corresponding mounting recess per 90 degrees with two steps to prevent the connecting element from directly knocking against the ground;

a handle formed on and protruding from the top end of the connecting element, extending out of the outer side of the connecting element and having a bottom face facing the connecting rod; and

two engaging protrusions formed on and protruding downwardly from the bottom face of the handle at an interval, and when the two toolboxes are stacked up with each other, the connecting element of the uppermost toolbox rotated 180 degrees relative to the body of the uppermost toolbox and the two engaging protrusions respectively inserted in and engaging with the two engaging holes of a corresponding holding recess of the body of the lowermost toolbox that is mounted below the mounting recess of the body of the uppermost toolbox.

2. The toolbox as claimed in claim 1 , wherein

the toolbox has two connecting elements; and

the body has two mounting recesses and two holding recesses.

3. The toolbox as claimed in claim 2 , wherein

each one of the four positioning segments is a curved rib; and

each one of the four locating segments is a curved stem.

4. The toolbox as claimed in claim 3 , wherein the handle of each one of the two connecting elements is L-shaped.

5. The toolbox as claimed in claim 4 , wherein each engaging protrusion of each one of the two connecting elements is circular.

6. The toolbox as claimed in claim 2 , wherein each engaging protrusion of each one of the two connecting elements is circular.

7. The toolbox as claimed in claim 3 , wherein each engaging protrusion of each one of the two connecting elements is circular.

8. The toolbox as claimed in claim 1 , wherein each engaging protrusion of each one of the at least two connecting elements is circular.