Patent ID: 8379493

Claim:
A spring-loaded driving member for a timepiece movement, comprising: (a) two coaxial barrels coupled in series, wherein each barrel has a rotatable cylindrical housing provided with an outer tooth arrangement and a base, and a spring rolled up inside the housing and having an outer end coupled to the housing and an inner end coupled to a core, wherein the respective cores of the barrels are interdependently rotatable and the respective bases of the barrels are located axially opposite one another, wherein the two barrels do not have a cover, and the respective springs of the two barrels are only separated from one another by a separation washer, and each housing has a substantially cylindrical central hub, in which a shaft common to both of the two barrels is housed, wherein at least one of the housings is rotatably mounted on the common shaft, and the two cores form part of a common tubular element mounted rotatably around the two central hubs of the two housings.