Patent ID: 7905336
Filing Date: 2011-03-15
Classification: F16J

Abstract:
1. A flexible boot for protecting a piston-cylinder unit of a disk brake including a piston, having a predefined axis, slidable in a cylinder in order to act on a brake pad, the flexible boot comprising at one end a first engagement ring which is adapted to be housed in a first groove of said cylinder, said groove being provided in the vicinity of an opening of said cylinder, and said flexible boot comprising, at an opposite end, a second engagement ring to be housed in a second groove provided in the vicinity of a head of said piston; said second ring having a first end suitable to be disposed closed to the pad and an opposite end disposed far from said pad in the rolled-up condition, the flexible boot also comprising a first connecting band between the first engagement ring and a second band suitable to be housed inside a seat formed in a portion of the cylinder disposed in the region of the opening and arranged radially, in a plane substantially perpendicular to the axis of the cylinder when the flexible boot is fitted on the piston-cylinder unit, in the rolled-up condition, the flexible boot also comprising a fifth band connected to the opposite end of said second engagement ring; said fifth band being arranged radially, in a plane substantially perpendicular to the axis of the cylinder when the flexible boot is fitted on the piston-cylinder unit; the flexible boot further comprising a surface, an annular portion of said surface adapted to face a wall of the pad when said boot is in a rolled-up configuration, said annular portion having at least one spacer element extending laterally from said surface and along less than the entirety of said annular portion, said spacer element being configured to have a circular cross section shape and to taper such that said spacer element reduces in cross sectional area as the spacer element extends laterally away from said surface, said spacer element thereby coming into contact with the wall of the pad at a minimized surface area of said spacer element and keeping the annular portion of the surface spaced from the wall of the pad; wherein the spacer elements are formed in pairs distributed across the annular portion with a distance between each adjacent pair, each pair formed of two adjacent spacer elements arranged at a distance closer to each other than the distance between each adjacent pair.