GB833662A - Improvements in and relating to electrically driven timepieces - Google Patents

Abstract

833,662. Electric clocks. PEMEW S.A. June 4, 1956 [June 6, 1955], No. 17158/56. Class 139 An electric clock of the electromagnetically maintained balance type has a winding and two magnetizable elements one of which is fixed and the other of which is carried by the balance staff, the maintaining impulses being obtained by mutual repulsion of the elements when the winding is energized to magnetize them with the same polarity. In the first embodiment, Fig. 1, the first magnetizable element F1 is carried by the balance staff a and moves inside a coil M to which the second magnetizable element F2 is attached. When the maintaining circuit is closed by a contact g meeting a contact l the elements Fl, F2 are magnetized with the same polarity and repel each other to give a maintaining impulse. A second pair of magnetizable elements may be located diametrically opposite to the pair F1, F2. In another example, Fig. 7, two connected windings M1, M2 are provided and the cooperating magnetizable elements F1, F2 are U-shaped. In the example of Fig. 9 the two co-operating magnetizable elements F1, F2 are finger shaped and each is surrounded by a winding. Instead of extending radially from the balance staff the elements F1, F2 may extend parallel thereto and two diametrically opposite pair of magnetizable elements may be provided. In another example, Fig. 10, the elements F1, F2 extend parallel to the axis of the balance staff and carry small circular discs r1, r2. In another example, the winding is a flat coil and the elements are of oval or elliptical shape. In another example, Fig. 16, two concentric stationary windings N1, N2 are provided and the elements F1, F2 are carried by the balance staff a and the winding N1 respectively. Two pairs of coils may be used as shown in Fig. 17.