| 摘要 |
818,678. Tuning forks. BULOVA WATCH CO. Inc. Feb. 16, 1956 [Feb. 16, 1955], No. 4908/56. Class 88 (2). [Also in Group XVIII] An electrical timepiece comprises an electric oscillating circuit (see Fig. 7) having a tuning fork 2, Fig. 1, which forms a mechanical vibrator of constant natural frequency and drives the going train. The tuning fork 2 is fixed, e.g. by soldering or welding to a member 5 fixed to the base-plate 1. The tine 3 carries at its free end a hollow cylindrical permanent magnet 6 the end wall 6b of which supports a magnetic bar 6a. The tine 4 carries at its free end a balance weight 7 having a threaded bore 7a in which a regulating screw 8 is located. Within the drum 6 is located a tubular member 10 fixed to a support 13 and carrying the two coils 11, 12 of the oscillating circuit, Fig. 7, constituting a tuning fork oscillator of the type disclosed in Specification 761,609, [Group XVIII]. |
