Patent ID: 8891339

Claim:
A timepiece gear train device with a power reserve, comprising: at least one energy storage means arranged to be powered by a motion imparted to a winding stem and/or to an oscillating weight, said energy storage means including at least one barrel; display means including at least one cannon-pinion and an hour wheel driven directly about a main pivot axis by a motion work; and at least one driving wheel driven directly or indirectly by said at least one barrel, said at least one driving wheel pivoting about a secondary pivot axis external to said at least one barrel, and said at least one driving wheel being friction coupled to said motion work on a friction surface coaxial to said secondary pivot axis of said at least one driving wheel, wherein said main pivot axis is secant to said at least one barrel, wherein said at least one driving wheel includes a driving cannon-pinion pivoting about a wheel body along said secondary pivot axis and connected to a shoulder of said wheel body which forms said friction surface by friction means formed by a friction spring, and wherein said driving cannon-pinion cooperates with a minute wheel belonging to said motion work and pivoting about a minute axis.