Foldable play yard

1. A foldable play yard comprising:

a floor assembly;

at least one top rail assembly; and

at least one corner post assembly comprising:

a first column, a lower end of the first column being pivoted to the floor assembly, an upper end of the first column being movably connected to the at least one top rail assembly; and

a second column movable relative to the first column, a lower end of the second column being movably connected to the floor assembly, an upper end of the second column being pivoted to the at least one top rail assembly;

wherein the floor assembly drives the second column to move relative to the first column to drive the at least one top rail assembly to be folded when the floor assembly is folded, and the floor assembly drives the second column to move relative to the first column to drive the at least one top rail assembly to be unfolded when the floor assembly is unfolded.

2. The foldable play yard of claim 1 , wherein the floor assembly comprises a floor hub and at least one floor beam having a first end and a second end, the floor hub is pivoted to the first end of the at least one floor beam, and the lower end of the first column is pivoted to an intervening portion of the at least one floor beam between the first end and the second end of the at least one floor beam.

3. The foldable play yard of claim 2 , wherein at least one lower slot is formed on the second end of the at least one floor beam, the at least one corner post assembly further comprises at least one lower pin adjacent to on the lower end of the second column and slidably passing through the at least one lower slot, and the lower end of the second column is rotatably and slidably disposed on the second end of the at least one floor beam by cooperation of the at least one lower pin and the at least one lower slot.

4. The foldable play yard of claim 2 , wherein the floor assembly further comprises at least one latch pivoted to the lower end of the first column for engaging with the second column, so as to stop the second column from being driven by the at least one floor beam to move relative to the first column.

5. The foldable play yard of claim 4 , wherein the floor assembly further comprises at least one cable connected to the at least one latch for driving the at least one latch to disengage from the second column to allow the second column to be driven by the at least one floor beam to move relative to the first column.

6. The foldable play yard of claim 4 , wherein the floor assembly further comprises at least one resilient component for biasing the at least one latch to engage with the second column.

7. The foldable play yard of claim 2 , wherein the floor assembly further comprises at least one pivoting component pivoted to the lower end of the second column and the second end of the at least one floor beam.

8. The foldable play yard of claim 2 , wherein the second column is pivoted to the second end of the at least one floor beam.

9. The foldable play yard of claim 8 , wherein the floor assembly further comprises at least one supporting base connected to the at least one floor beam, and the at least one floor beam drives the at least one supporting base to be located beneath the second column when the floor assembly is unfolded.

10. The foldable play yard of claim 9 , wherein the at least one corner post assembly further comprises a wheel set disposed on the lower end of the second column, the wheel set is hidden between the at least one supporting base and the second column when the floor assembly is unfolded to drive the at least one supporting base to be located beneath the second column, and the wheel set is exposed when the floor assembly is folded to drive the at least one supporting base to leave from the second column.

11. The foldable play yard of claim 2 , wherein the at least one corner post assembly further comprises a wheel set disposed on the lower end of the first column.

12. The foldable play yard of claim 1 , wherein the first column is movably sleeved inside the second column.

13. The foldable play yard of claim 12 , wherein the at least one corner post assembly further comprises an elastic component connected to the first column and the second column, and the elastic component is elastically deformed when the floor assembly is folded to drive the second column to move relative to the first column.

14. The foldable play yard of claim 1 , wherein the at least one top rail assembly comprises:

a bracket; and

at least one upper beam having a first end and a second end, the bracket being pivoted to the first end of the at least one upper beam, the second column being pivoted to an intervening portion of the at least one upper beam between the first end and the second end of the at least one upper beam, an upper slot being formed on the second end of the at least one upper beam, the at least one corner post assembly further comprising an upper pin adjacent to the upper end of the first column and slidably passing through the upper slot, and the upper end of the first column being rotatably and slidably disposed on the at least one upper beam by cooperation of the upper pin and the upper slot.

15. The foldable play yard of claim 14 , wherein the at least one top rail assembly further comprises at least one lower beam having a first end and a second end, the first end of the at least one lower beam is pivoted to the bracket, and the second end of the at least one lower beam is pivoted to the second column.