Expanding wheel frame wagon

1. A folding cart comprising:

a frame including a front frame and a rear frame, wherein the front frame opposes the rear frame;

a floor assembly, comprising a front frame member and a rear frame member, wherein the front frame member is hinged to the rear frame member, wherein the front frame member and the rear frame member are hinged between the front frame and the rear frame;

a wheel retracting assembly including: a rear wheel half-shaft rotary rod, a rear wheel half shaft, a rotary pulling rod, an automatic foot assembly and a rotary connecting bar;

wherein the rear wheel half-shaft rotary rod is pivotally connected to the rear frame member at a first rear wheel half-shaft rotary rod end, wherein the rear wheel half shaft is disposed at a second rear wheel half-shaft rotary rod end, for connecting a rear wheel, wherein the first rear wheel half-shaft rotary rod end is opposite the second rear wheel half-shaft rotary rod end; and

wherein the rotary pulling rod is pivotally connected to the rear frame member at a first rotary pulling rod end, and at a second rotary pulling rod end pivotally connected to the rear wheel half-shaft rotary rod to drive the rear wheel half-shaft rotary rod to retract, wherein the first rotary pulling rod end, is opposite to the second rotary pulling rod end.

2. The folding cart according to claim 1 , wherein the wheel retracting assembly further comprises a half-shaft rotary rod hinge, wherein the rear wheel half-shaft rotary rod is inclinedly disposed at the rear frame member relative to a horizontal plane via the half-shaft rotary rod hinge.

3. The folding cart according to claim 1 , wherein the rear wheel half-shaft rotary rod forms a four bar mechanism in a parallelogram shape, wherein the rear wheel half shaft stays in a position parallel to the ground during the rotation of the rear wheel half-shaft rotary rod.

4. The folding cart according to claim 1 , wherein the wheel retracting assembly further comprises two sets of expansion rod mechanisms, wherein two ends of each set of the expansion rod mechanism are pivotally connected to the rear frame member and the rear wheel half-shaft rotary rod, respectively.

5. The folding cart according to claim 4 , wherein the expansion rod mechanism further comprises a first rod and a second rod which are sleeved, wherein the first rod is connected to the rear frame member, and wherein the second rod is connected to the rear wheel half-shaft rotary rod, wherein when the floor assembly is in a working state the expansion rod mechanism is retracted, wherein when the floor assembly is in a folding state the expansion rod mechanism is extended.

6. The folding cart according to claim 1 , wherein the wheel retracting assembly further comprises an automatic foot assembly and a rotary connecting bar, wherein the rotary connecting bar is hinged to the rear frame member at a rotary connecting bar first end, and wherein a rotary connecting bar second end is hinged to the automatic foot assembly, wherein when the rear frame member is folded, the automatic foot assembly extends out to allow the folding cart to stand.

7. The folding cart according to claim 1 , wherein the folding cart further comprises:

a main basket, comprising a front main basket member and a rear main basket member which are hinged to each other and disposed above the front frame member and the rear frame member;

two sets of sidewall assemblies, each set comprising a primary sidewall assembly rear floor crossbar support and a primary sidewall assembly front floor crossbar support which are hinged to each other and form certain angle with each other, the primary sidewall assembly front floor crossbar support is hinged to the front frame via the primary sidewall assembly left front sidewall link, and the primary sidewall assembly rear floor crossbar supports is hinged to the rear frame via the primary sidewall assembly left rear sidewall link, the primary sidewall assembly rear floor crossbar supports and the primary sidewall assembly front floor crossbar support are hinged to each other at a floor crossbar connector, a floor crossbar is connected between two floor crossbar connectors, and the floor crossbar is disposed below the floor assembly;

a main basket front left support and a main basket front right support are hinged between the primary sidewall assembly front floor crossbar support and the front frame, a main basket rear left support and a main basket rear right support are hinged between the primary sidewall assembly rear floor crossbar supports and the rear frame.

8. The folding cart according to claim 7 , wherein the wheel retracting assembly further comprises a locking mechanism which is pivotally connected to the rotary connecting bar, and when the folding cart is in a working state, the locking mechanism hooks the floor crossbar, when the locking mechanism is pulled upwardly, the locking mechanism is separated from the floor crossbar and drives the front frame member and the rear frame member to fold relative to each other.

9. The folding cart according to claim 8 , wherein each set of sidewall assembly further comprises a secondary sidewall assembly rear link and a secondary sidewall assembly front link which are hinged to each other, the secondary sidewall assembly rear link is hinged to the front frame, and the secondary sidewall assembly front link is hinged to the rear frame.

10. The folding cart according to claim 8 , wherein the folding cart further comprises a handle, the handle is hinged to the rear frame, and the handle further comprises a handle support upper section and a handle support lower section which are hinged to each other, the handle support upper section is further hinged to a handle extension of the handle, and the handle support lower section is further hinged to the rear frame.