Tandem pneumatic brake booster
AssigneeRobert Bosch GmbH
InventorsIgnacio Diaz Bueno, Christian Ast, Christian Caquet, Jean-Pierre Michon
Life of this patent
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Abstract
The invention relates to a tandem pneumatic brake booster (1) for a vehicle. The objective is to prevent a blocking of a booster thrust rod (4) in the maximum travel position. The blocking appears following a sealed adhesion of a first plate skirt (12) on a seal (22) of the tandem booster. This seal blocks a vacuum in a first front chamber (5). To prevent this blocking, provision is made to crenelate a first lip (23) pressed against the pneumatic piston (3) of a seal. Merlons prevent a sealed adhesion of the plate skirt (12) over the whole seal (22). This absence of adhesion creates a leakage of air to the first front chamber (5) and allows a return to a rest position.
Claims17
Tandem pneumatic brake booster (1) for a vehicle comprising a shell (2), a pneumatic piston (3) sliding in the shell, two pairs of chambers, each pair comprising a front chamber (5,7) and a rear chamber (6,8), the front chamber being situated closer to a brake master cylinder than the rear chamber, a fixed partition (14) in the booster, separating a first front chamber (5) from a second rear chamber (8), a first plate skirt (12), separating the first front chamber (5) from the first rear chamber (6), and a second plate skirt (13), separating the second front chamber (7) from the second rear chamber (8), these plate skirts being movable, sealed and moving the pneumatic piston (3), a seal (22) fixed to the fixed partition, the pneumatic piston (3) sliding inside this seal (22) in a sealed manner, this seal comprising a first lip (23) pressed on the pneumatic piston (3) in a sealed manner, and extending parallel to the axis of movement of the pneumatic piston, characterized in that the first lip (23) is crenelated.
Dependencies are inferred from the claim text.