Electromechanical clock

[3. The combination defined in claim 2 wherein said mounting means comprises a rocker pivoted to a stationary support for swinging about a horizontal axis, said stop means being part of said

• support.] 4. The combination defined in claim [3] 2 wherein said extension comprises a horizontal spur secured to said resilient element near said upper end thereof for oscillation
• thereabout. 5. The combination defined in claim 4 wherein said stop means is an edge of a horizontal slot in said support periodically enterable by
• said spur. 6. The combination defined in claim 4 wherein said driven member is a cam disk, said formation being at least one hump on said cam
• disk. 7. The combination defined in claim 6 wherein said stop means
• substantially coincides with a vertical axial plane of said cam disk. 8. The combination defined in claim 7 wherein said horizontal axis lies in said vertical plane, said rocker being provided with a pivot pin carrying
• said cam disk. 9. The combination defined in claim 8 wherein said biasing means comprises a weight at an extremity of said rocker remote from said pivot pin, said first pinion being carried on said rocker at an
• intermediate location between said extremity and said axis. 10. The combination defined in claim 8 wherein said second pinion is mounted on
• said pivot pin and is rigid with said cam disk. 11. The combination defined in claim 10 wherein said first pinion is stepped and has two toothed portions of different diameter respectively meshing with said
• driving gear and with said second pinion. 12. The combination defined in claim 11 wherein the toothed portion meshing with said second pinion has
• the larger diameter. 13. The combination defined in claim 12 wherein said
• driving gear is substantially larger than said pinions. 14. The combination defined in claim 13 wherein said driving gear has 72 teeth, said toothed portions have 22 and 20 teeth, respectively, and said second
• pinion has 20 teeth. 15. The combination defined in claim 14 wherein said cam disk is provided with two diametrically opposite humps and said
• torsion pendulum has an oscillatory cycle of about 10 to 15 seconds. 16. The combination defined in claim 8 wherein said support is provided with a cutout, said first pinion being provided with a shaft received with
• play in said cutout for limiting the swing of said rocker. 17. The combination defined in claim 6 wherein said pinions, said rocker and said
• cam disk [consists] consist of plastic material. 18. The combination defined in claim 4 wherein said spur is a resinous
• casting on said resilient element. 19. The combination defined in claim 2 wherein said extension engages said stop means substantially in a midposition of a pendulum swing.

[20. The combination defined in claim 1 wherein said clockwork comprises an electrodynamic escapement.] In a timepiece, in combination:

• a clockwork powered by a source of electric energy;
• a torsion pendulum with an elongate resilient element having a fixedly anchored upper end and a freely rotatable lower end;
• mechanical transmission means comprising a gear train including a driving gear positively coupled with said clockwork, a first pinion adjacent said driving gear for entrainment thereby, movable mounting means for said first pinion enabling its disengagement from said driving gear, a second pinion meshing with said first pinion with a sense of rotation tending to disengage said first pinion from said driving gear upon a halting of said second pinion, biasing means for said mounting means tending to maintain said first pinion engaged with said driving gear, and a driven member positively coupled with said second pinion;
• and
• decoupling means comprising an oscillatable extension of said resilient element, a formation on said driven member intermittently engageable with said extension, and stop means periodically engageable by said extension in a predetermined phase of an oscillatory cycle, said extension lying in the path of said formation only in the vicinity of said stop means and resisting displacement by said formation while being urged by said resilient element against said stop means, said extension engaging said stop means substantially in a midposition of a pendulum swing.

In a timepiece, in combination:

• a clockwork powered by a source of electric energy;
• a torsion pendulum with an elongate resilient element having a fixedly anchored upper end and a freely rotatable weighted lower end, said resilient element being provided with a transverse spur secured thereto near said upper end for oscillation thereabout;
• mechanical transmission means forming a power train between said clockwork and said resilient element for periodically stepping said torsion pendulum, said transmission means including a driving member positively coupled with said clockwork, a driven member having a formation intermittently engageable with said spur during a predetermined phase of each oscillatory cycle of said torsion pendulum, and a releasable coupling between said driving and driven members yieldable to interrupt said power train upon said driven member encountering a significant resistance;
• and
• stop means in the path of said spur for arresting same during a predetermined fraction of each oscillatory cycle while allowing said torsion pendulum to complete the cycle at an accelerated rate resulting from a partial immobilization of said resilient element, said formation coacting with said spur during said fraction whereby said driven member encounters a resistance sufficient to release said coupling until said spur disengages said stop means following a reversal of the rotation of said torsion pendulum.