Patent attributes
In a plunger master brake cylinder (1), the closed end (5) of the main bore (3) is manufactured in one piece with the housing (2). The pistons (6,7) are inserted from the open end (4) of the main bore (3). In order to prevent the pistons (6,7) from slipping out of the main bore (3) prior to assembly in the vehicle, a retaining pin 23 is provided, which has a length greater than the diameter of the pistons (6,7) and than the diameter of the open end (4) of the main bore (3). The pin 23 extends through radial holes (20) in the spring retainer (13) of the compression spring 12 coupled to the outer piston (7). The pin is inserted through a small radial opening 26 in the housing 2 and is limited in its outward movement by a step (25) in the main bore (3).