Patent ID: 8894275

Claim:
A timepiece barrel for pivotal assembly between a bottom plate and a bridge and comprising at least one spring, housed between a pivoting drum and a ratchet and hooked between said drum at the outer end thereof and an arbour at the inner end thereof, said arbour being pivotally integral with said ratchet about a pivot axis, said barrel including a single-piece sub-assembly coaxial with said arbour and carrying said ratchet and including, on either side of said ratchet, a hub for pivotally guiding said barrel in said bottom plate, said hub forming one end of said arbour, wherein said ratchet forms a closing cover of said drum and is placed between said drum and said bottom plate, and in that said single-piece sub-assembly is pivoted on an upper shoulder in a bore in said drum on an end pipe whose external shoulder pivots in a bore of said bridge or of a jewel in said bridge.