Coupler and anti-creep mechanism for the same

1. An anti-creep mechanism for a coupler comprising a lower lockpin rod, a coupler shank and a rotation shaft, wherein the rotation shaft is disposed in an elongate mounting hole of the lower lockpin rod and a circular mounting hole of the coupler shank so that the lower lockpin rod and the coupler shank are hinged together, wherein after the lower lockpin rod is moved upwardly, an anti-creep bulge of the lower lockpin rod abuts against an anti-creep surface of the coupler shank to prevent the coupler from being abnormally unlocked, further comprising:

a boss axially disposed on an upper surface of the rotation shaft; and

a groove axially provided in a wall of the mounting hole of the coupler shank above the rotation shaft to receive the boss of the rotation shaft, wherein the rotation shaft is axially movable relative to the lower lockpin rod and the coupler shank and has two operating positions,

wherein when the rotation shaft is moved to a first operating position, an inner end portion of the boss is positioned in the elongate mounting hole of the lower lockpin rod, and a top wall of the elongate mounting hole abuts against the boss, and if the lower lockpin rod is rotated in a coupler unlocking direction, the anti-creep bulge of the lower lockpin rod abuts against the anti-creep surface of the coupler shank and the boss abuts against a sidewall of the groove in the coupler shank; and

wherein when the rotation shaft is moved to a second operating position, the boss is positioned in the groove of the mounting hole of the coupler shank, and the top wall of the elongate mounting hole abuts against an outer circumferential surface of the rotation shaft.

2. The anti-creep mechanism for coupler according to claim 1 , wherein, a chamfer is disposed at the inner end portion of the boss.

3. The anti-creep mechanism for coupler according to claim 1 , wherein the boss is disposed on an outer circumferential surface of one end portion of the rotation shaft, and a stop shoulder is provided at the one end portion of the rotation shaft, wherein the stop shoulder is configured to abut against the coupler shank to allow the rotation shaft to be in the first operating position.

4. The anti-creep mechanism for coupler according to claim 3 , wherein, a pull-tab is provided in an axial outer end surface of the stop shoulder to allow the rotation shaft to be in the second operating position.

5. The anti-creep mechanism for coupler according to claim 4 , further comprising:

a spring provided on the rotation shaft at an outer side of the coupler shank;

a stop component disposed on the rotation shaft at an outer side of the spring, wherein when the rotation shaft is in the second operating position, the spring is compressed and deformed; and

a split pin inserted in a radial through hole of the rotation shaft to limit an axial displacement of the stop component.

6. The anti-creep mechanism for coupler according to claim 5 , wherein the stop component is provided with a split pin receiving hole, and the split pin is inserted in the split pin receiving hole of the stop component and the radial through hole of the rotation shaft.

7. The anti-creep mechanism for coupler according to claim 6 , wherein the stop component is an annular stop collar provided on the rotation shaft.

8. The anti-creep mechanism for coupler according to claim 7 , wherein an annular groove is provided on an outer cylindrical surface of the annular stop collar, and the split pin receiving hole is disposed at a bottom of the annular groove.

9. A coupler comprising an anti-creep mechanism for coupler according to claim 1 .