| 摘要 |
1,096,039. Clocks and watches. CITIZEN TOKEI KABUSHIKI KAISHA. Feb. 21, 1966 [Feb. 19, 1965 (2)], No. 7448/66. Heading G3T. An escapement mechanism for a watch comprises a lever 11 pivoted on an arbor 33 to oscillate between stop positions defined by pins 12, 13, an entry pallet 18 and an exit pallet 19 fixed to the lever, an escape wheel 5 co-operating with the pallets and a permanent magnet 8 placed in a position substantially diametrically opposite the lever with respect to the escape wheel. The function of the magnet is to exert a torque on the escape wheel so that the lever is urged into locked positions at the end of each intermittent stepped rotation of the escape wheel as illustrated in Fig. 2 and Fig. 5 (not shown) and also to resist reverse rotation of the wheel at each release of the entry and exit pallets. For this purpose, a traction wheel 7 made of a magnetizable material such as iron and having teeth 7a is spot welded to the escape wheel. A roller (2), Fig. 1 (not shown) having a flange 2a and an impulse pin 3 is attached to a balance wheel (1) which is of the conventional type used in electronic time pieces in which magnets (1a) co-operate with drive and search coils (not shown) to maintain the oscillation. The impulse pin strikes forks 14, 15 to produce oscillations of the lever 11, the pallets 18, 19 transmitting an intermittent drive to the escape wheel 5. The interaction of the magnet 8 with the iron teeth 7a ensures correct location of the escape wheel at each stopping point of its intermittent rotation. In a modification, Fig. 7 (not shown) two permanent magnets (8a), (8b) are mounted on a plate (43) and their position with respect to the teeth 7a may be adjusted by pivoting the plate about the escape wheel spindle (35). A screw (44) engaging a slot (45) of the plate locks the plate in position. In a second modification, Figs. 8, 9 (not shown), the jaws of a yoke-shaped magnet (8b) are mounted opposite holes (49) cut in the escape wheel and a traction wheel is not required. The holes (49) may be extended to the inner rim of the escapement wheel to form recesses (51) as illustrated in Fig. 10 (not shown).
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