CUP OF A MASTER CYLINDER, ADVANTAGEOUSLY A TANDEM MASTER CYLINDER AND TANDEM MASTER CYLINDER PROVIDED WITH SUCH CUPS

摘要

The invention relates to a cup of a master cylinder engaging with the primary piston or the secondary piston thereof and subjected to the pressure of the brake fluid in the primary chamber and the secondary chamber. The cup (60) has two large grooves (622, 624) bordered: with a rib (627) between the heel (621) and the first groove (622), with a rib (623) between the first groove (622) and the second groove (624), with a rib (625) between the second groove (624) and the small grooves (626), said ribs (627, 623, 625) projecting (DS) from the cylindrical surface (D) of the heel (621) in the mounting position of the cup (50) such as to separate the heel (620) from the surface of the piston (30) and to form a gap (621) containing a film of brake fluid (628) between the heel (620) and the surface of the piston (30). The invention relates in particular to a tandem master cylinder provided with such cups.