VEHICLE STEP APPARATUS AND EXTENDING AND RETRACTING DEVICE THEREOF

1 . An extending and retracting device for a vehicle step apparatus, comprising:

a mounting bracket;

a step bracket;

a first arm defining a first end pivotally connected to the mounting bracket and a second end pivotally connected to the step bracket;

a second arm defining a first end pivotally connected to the mounting bracket and a second end;

a third arm defining a first end pivotally connected to the second end of the second arm and a second end pivotally connected to the step bracket; and

a fourth arm defining a first end pivotally connected to the second end of the second arm and the first end of the third arm respectively, and a second end pivotally connected to the first arm.

2 . The extending and retracting device as set forth in claim 1 , wherein the second arm is substantially coaxial with the third arm, and the first arm is substantially parallel to the second and third arms.

3 . The extending and retracting device as set forth in claim 1 , wherein the second end of the fourth arm is connected with a middle portion of the first arm.

4 . The extending and retracting device as set forth in claim 1 , wherein the first to fourth arms are in a form of a plate.

5 . The extending and retracting device as set forth in claim 1 , wherein the first end of the first arm is connected to the mounting bracket via a first pivot, and the second end of the first arm is connected to the step bracket via a second pivot;

the first end of the second arm is connected to the mounting bracket via a third pivot;

the second end of the second arm and the first end of the third arm are connected to the first end of the fourth arm via a fourth pivot;

the second end of the third arm is connected to the step bracket via a fifth pivot; and

the second end of the fourth arm is connected to the first arm via a sixth pivot.

6 . The extending and retracting device as set forth in claim 1 , wherein the second end of the second arm has a U-shaped second arm groove, and the first end of the third arm has a protrusion adapted to be fitted within the second arm groove.

7 . The extending and retracting device as set forth in claim 6 , wherein the protrusion includes two lugs spaced apart from each other, and the first end of the fourth arm is fitted between the two lugs.

8 . The extending and retracting device as set forth in claim 1 , wherein the first arm is provided with a first arm groove, and the second end of the fourth arm is fitted within the first arm groove.

9 . The extending and retracting device as set forth in claim 1 , wherein the step bracket has a bracket groove, and the second end of the first arm and the second end of the third arm are fitted within the bracket groove.

10 . A vehicle step apparatus, comprising:

an extending and retracting device which includes:

a mounting bracket;

a step bracket;

a first arm defining a first end pivotally connected to the mounting bracket and a second end pivotally connected to the step bracket;

a second arm defining a first end pivotally connected to the mounting bracket and a second end;

a third arm defining a first end pivotally connected to the second end of the second arm and a second end pivotally connected to the step bracket;

a fourth arm defining a first end pivotally connected to the second end of the second arm and the first end of the third arm respectively, and a second end pivotally connected to the first arm;

a step member mounted on the step bracket of the extending and retracting device; and

a drive device driving at least one of the first and second arms to drive the extending and retracting device to move the step member between an extended position and a retracted position.

11 . The vehicle step apparatus as set forth in claim 10 , wherein the second arm is substantially coaxial with the third arm, and the first arm is substantially parallel to the second and third arms.

12 . The vehicle step apparatus as set forth in claim 10 , wherein the second end of the fourth arm is connected with a middle portion of the first arm.

13 . The vehicle step apparatus as set forth in claim 10 , wherein the first to fourth arms are in a form of a plate.

14 . The vehicle step apparatus as set forth in claim 10 , wherein the first end of the first arm is connected to the mounting bracket via a first pivot, and the second end of the first arm is connected to the step bracket via a second pivot;

the first end of the second arm is connected to the mounting bracket via a third pivot;

the second end of the second arm and the first end of the third arm are connected to the first end of the fourth arm via a fourth pivot;

the second end of the third arm is connected to the step bracket via a fifth pivot; and

the second end of the fourth arm is connected to the first arm via a sixth pivot.

15 . The vehicle step apparatus as set forth in claim 10 , wherein the second end of the second arm has a U-shaped second arm groove, and the first end of the third arm has a protrusion adapted to be fitted within the second arm groove.

16 . The vehicle step apparatus as set forth in claim 15 , wherein the protrusion includes two lugs spaced apart from each other, and the first end of the fourth arm is fitted between the two lugs.

17 . The vehicle step apparatus as set forth in claim 10 , wherein the first arm is provided with a first arm groove, and the second end of the fourth arm is fitted within the first arm groove.

18 . The vehicle step apparatus as set forth in claim 10 , wherein the step bracket has a bracket groove, and the second end of the first arm and the second end of the third arm are fitted within the bracket groove.