The invention relates to a dual-mode
drum brake for a vehicle, which operates as a service
brake in simplex mode and as a
parking brake in duo
servo mode. The invention also relates to a vehicle including such a
drum brake, and to a method for assembling such a
drum brake. When operating as a service
brake, a first
actuator separates two movable ends of the
brake shoes while the opposite ends thereof both abut with the housing of a second
actuator. When operating as a
parking brake, said second
actuator separates the two abutting ends from one another, while the movable ends engage one another via a floating inserted element, for example a wear-adjusting rod. All braking or holding torque is transmitted to the plate by the
abutment end of a single
brake shoe, by engaging, on one side, the housing of the second actuator. The second actuator uses two pistons, one of which is a spring
package, moved by a screw-and-nut
system driven by a pre-assembled sub-
assembly of gears with axes that are all parallel to the movement of the pistons. The
system is driven, on the other side of the plate, by an
electric motor-
reducer with double planetary gearset sharing a single ring gear.