Patent ID: 8407854

Claim:
A protective device for a castor comprising: a mounting ring for mounting to the castor; a driving piece secured on the mounting ring; and a positioning plate secured on the mounting ring and detachably connected with the driving piece, wherein: the mounting ring has an outer periphery formed with a breakable portion located beside the driving piece; the breakable portion allowing the mounting ring to be removed from the castor; the driving piece has a first end extending from the mounting ring and a second end formed with a pull tab; the positioning plate has a first end extending from the mounting ring and a second end formed with a plurality of connecting blocks detachably connected with the pull tab of the driving piece; the first end of the driving piece is formed with a connecting portion connected with the mounting ring; the connecting portion of the driving piece has a first side connected with the breakable portion of the mounting ring; the first side of the connecting portion of the driving piece is detachable from the mounting ring through the breakable portion of the mounting ring; the connecting portion of the driving piece has a second side fixedly combined with the mounting ring; the second side of the connecting portion of the driving piece is non-detachable from the mounting ring; and the driving piece is combined with the mounting ring without detachment.