US Patent 10392783 Cylinder device

A bucket cylinder includes a cylindrical tube, a rod having a cylindrical boss part mounted to a protruding end side of the rod, and a protective cover having one side supported by a cover guide provided on the tube, while the other side is mounted on the boss part. A protective protrusion protruding outward in a radial direction of the boss part and protecting the boss part and the protective cover is provided on the boss part. The protective cover is formed having a plate shape by a material having elasticity, and the protective cover includes a plate part for protecting the rod between the cover guide and the boss part and a winding part formed so as to be wound around an outer periphery of the boss part from a distal end side of the plate part. A protective protrusion engaging hole into which the protective protrusion is engaged is provided in the winding part at a position corresponding to the protective protrusion.