Patent ID: 7712953

Claim:
A clutch device for a timepiece, comprising: first and second coaxial rotary mobile parts ( 1 , 2 ) mounted on an axis ( 3 ) and able to take up a relative axial coupled position in which rotation of said first mobile part ( 1 ) causes rotation of said second mobile part ( 2 ) and a relative axial uncoupled position in which rotation of said first mobile part ( 1 ) does not cause rotation of said second mobile part ( 2 ); a clamp ( 20 ) moving said second mobile part axially relative to said first mobile part; said second mobile part comprising a pipe ( 11 ) surrounding said axis ( 3 ) and a member ( 10 ) surrounding and rigidly assembled to said pipe, said member ( 10 ) being actuable by said clamp ( 20 ); and a friction element of viscoelastic material ( 30 ) intercalated between said first and second mobile parts ( 1 , 2 ) so as to transmit rotation of said first mobile part ( 1 ) to said second mobile part ( 2 ) in said coupled position, said friction element being housed partly in a cavity ( 31 ) defined by said pipe ( 11 ) and said member ( 10 ).