679,313. Timepieces. MONTRES ROLEX SOC. ANON. July 10, 1950 [July 16, 1949], No. 17238/50. Class 139 A self-winding timepiece comprises two masses mounted so as to be able to effect complete revolutions, each mass co-operating with a wheel which forms part of the winding train. The masses, 9a, 9b, Fig. 2, are respectivtly carried by arms 8a, 8b, Figs 1 and 2, secured to pinions 7a, 7b carried by shafts 6a, 6b respectively. The .shafts 6a, 6b are rotatable in bearings 5. The pinions 7a, 7b both mesh with a wheel 12 rigid with a pinion 13 which drives a wheel 14 rigid with the barrel ratchet 15. The masses are in a cage 1 fixed to the barrel bridge 2.