Patent GB-352963-A (GB)
Title: Improvements relating to electric clocks
IPC: G04C13/04
Filed: 1930-01-15
Abstract: 352,963. Electric clocks. KRAUSE, A. C., 227, Blackfriars Road, London. Jan. 15, 1930, No. 1483. [Class 139.] Winding apparatus, electric. - In master clock mechanism an arm 47 is rocked by an electro-magnet 41 to close the secondary clock circuit at 77, 85, the circuit of the magnet being closed intermittently by contact of a member oscillated by the clockwork with a member rotated by the clockwork. The arm 47 is also provided with means, pawl 55, for simultaneously rewinding the mainspring or weight. The pendulum 12 (or a balance wheel) has a pin-and-slot connection with an arm 13 on the staff 14 of the anchor 15, the escape wheel 17 controlled thereby having rigid with its arbor 11 two arms. 10, carrying contact shoes 32. This arbor 11 is driven by mainspring 18 through wheel 58 and train 19. An oscillatory arm 20, carrying a contact pin 21, is mounted on an insulated member 22 on a plate 23 which is loose on spindle 24 and has an arm 25 attached by spring 26 to an arm 27 rigid with spindle 24. Plate 23 has a second arm 29 the lip 28 of which is thus pressed by spring 26 against the arm 27. Spindle 24 is oscillated from the pendulum by a link 31. The escape wheel rotates once a minute, so that each half minute an arm 10 reaches pin 21. Normally this pin is raised and lowered each swing of the pendulum but at the half minute, a shoe 32 obstructs it. Thus as the pendulum, and therefore arm 27, continues to move, spring 26 is stretched and pin 21 is pressed with increasing firmness against shoe 32. To overcome the retarding effect this would have, a shoe 34 on an arm 33 rigid with spindle 24 rotates the arm 10 to separate the contacts 32, 21. Closure of these contacts energizes a magnet 41 to attract its armature 46, Fig. 3. This armature is on an arm 47 pivoted at 48 and connected by link 51 to a lever 49 pivoted at 50 and carrying a pawl 55 ; this pawl at each energization advances a ratchet wheel 57 at the other end of the mainspring 18 to that driving the train 19. As the lever 47 moves to the right, once each half minute, Fig. 3, a pin 81 on it permits a spring 80 to rock a lever 78, pivoted at 79, counterclockwise to close contacts 83, 84 for the secondary clocks. Contact 83 is electrically connected to post 77, and 84 to post 85. Overwinding, preventing.-Link 51 and arm 49 are connected by a pin and slot 63, 62, pin 63 being pressed to the right-hand end of the slot by a spring 64. When the mainspring is fully wound, it holds pin 63 stationary and the reciprocation of link 51 merely stresses spring 64. Releasing mainspring.-To permit mainspring 18 to unwind fully a cord is pulled to rotate a lever which coacts with pin 74 on pawl 55 and, with a holding pawl, to remove both pawls and free the ratchet 57. Winding apparatus, hand.-To stress the mainspring manually, a handle 66 pivoted at 67 has a lip 70 which rocks lever 47 and pawl 35 to the right each time 66 is rocked. To prevent energization of the secondary clocks at this operation the contact 84 is on a lever 87 which is rotated counterclockwise by a spring 88 and meets a pin 89 on handle 66. When the latter advances the pawl 55, lever 87 follows pin 89 and rocks the contact 84 to the left, Fig. 3, away from the contact 83 which is moving leftwards. To send impulses to the secondary clocks independent of the master clock shown, the lever 87 is oscillated.