Patent ID: 8220110

Claim:
A castor, comprising: a connecting board; a base bracket pivotally connected with the connecting board; a locking disk connected with the connecting board; a wheel rotatably mounted on the base bracket; a mounting bracket secured on the base bracket; a braking member pivotally connected with the mounting bracket and releasably locked onto the locking disk and the wheel to releasably lock the base bracket relative the connecting board and to releasably lock the wheel relative the base bracket; and a drive unit pivotally connected with the braking member to move the braking member relative to the locking disk and the wheel; wherein the locking disk has a periphery provided with a toothed locking portion; the braking member has a first end provided with a toothed locking section that is movable to engage the locking portion of the locking disk and a second end provided with a mounting portion; the second end portion of the braking member has a side provided with a braking section that is movable to press the wheel; the drive unit includes a driving plate pivotally connected with the braking member, and a linking block pivotally connected with the driving plate; the driving plate of the drive unit has a first end provided with a first pivot section and a second end provided with a second pivot section; the first pivot section of the driving plate is pivotally connected with the linking block of the drive unit; the second pivot section of the driving plate is pivotally connected with the mounting portion of the braking member.