Patent ID: 7950108

Claim:
A castor, comprising a suspension unit, a castor body, a wheel unit, and a brake unit, wherein the suspension unit includes an upright fixing bolt and a locking member secured on the fixing bolt; the castor body is rotatably mounted on the fixing bolt of the suspension unit; the wheel unit includes two rollers each rotatably mounted on the castor body and each having a side formed with a plurality of locking grooves; the brake unit includes a positioning block movably mounted in the castor body and movable to press the locking member of the suspension unit to lock the castor body onto the locking member of the suspension unit, a sliding block movably mounted in the castor body and combined with the positioning block to move the positioning block in the castor body, a biasing member mounted in the castor body and biased between the castor body and the sliding block to push the sliding block outwardly relative to the positioning block, a drive member pivotally mounted on the castor body and abutting the sliding block to push the sliding block toward the positioning block, and a braking pin mounted on the drive member to move with the drive member and movable into one of the locking grooves of each of the rollers to brake and lock each of the rollers of the wheel unit onto the castor body.