GB908510A - Ship's bell clock - Google Patents

Abstract

908,510. Clocks. GENERAL TIME CORPORATION. Oct. 30, 1959 [April 24, 1959], No. 36880/59. Class 139. In a ship's striking clock the striking mechanism comprises a spring 27 (shown diagrammatically), gearing 41, 42, 44, 45, 47, a vane 43, and a double star-wheel 25a, 25b which cooperates with an arm 30 to transmit movement to the hammer 22 through the linkage 31, 33, 34. The shaft 40 of the striking train carries a two-lobe cam 50 which is normally locked by a detent 55 pivotally mounted on a shaft 57 on which is also pivoted the lifting piece 60 the end 61 of which co-operates with a cam 62 having an hour lobe 63, a half-hour lobe 64 and a forty-five minute lobe 110 the purpose of which is described later. The extension 70 of the lifting piece 60 locks the gear 47 of the striking train when the lifting piece 60 is raised by the cam 62 until drop-off occurs when the striking train is freed. The periphery of the hour snail 80 is divided into three groups of eight steps. The detent 56 has a rack hook extension 100. The gathering pins 101, 102 extend from the cam 50 on the shaft 40. At the forty-five minute position the lobe 110 of the cam 62 raises the lifting piece 60 to remove the detent 55 from the cam 50 and at drop-off the striking train is freed for one half revolution of the cam 50 which is then arrested by the detent 55. During this half revolution the star-wheel 25a, 25b is rotated one step but the hammer is not actuated as the silencing cam 115 on the minute shaft 11 engages the lever arm 32 to remove the arm 30 from the star-wheel 25a, 25b. The striking mechanism is thus conditioned to strike an even number of blows on the hour. If the hand-setting mechanism is actuated to move the minute hand from a position in advance of, to a position before the forty-five minute position, the shaft 40 is not released again by the lobe 110 acting on the lifting piece since the lobe 51 of the cam 50 is too big to be released from the detent 55.