The present invention relates to a pendulum mechanism, adapted to be attached to the casing of a clockwork for use together with the clockwork, which operates independently of the clockwork, and which comprises a pivot bearing, a pendulum arm mounted on the bearing for swinging motion, and an electrical drive mechanism for the pendulum comprising a permanent magnet carried by the pendulum adjacent its lower end and cooperating with a coil mounted on a circuit board located below the clockwork casing and carrying the electronics for driving the pendulum.
An autonomously operating pendulum arrangement, which can be attached to a crystal-controlled clockwork, is discussed in Haag et al U.S. Pat. No. 4,043,118, assigned to the assignee of the instant application. This known arrangement consists of a pendulum housing adapted to be fastened to the lower side of the clockwork casing and carrying a circuit board on which are mounted the electrical components required to drive the pendulum. The arrangement includes a bearing device for the pendulum arm which bearing device is attached as a separate element to the upper side of the clockwork casing, and a device for suspending the pendulum is provided at the lower side of the pendulum arm. The housing is also provided with a lateral arm on which the bell of a clock-striking system can be mounted.
This known arrangement has the disadvantage that the proper functioning of its various components, i.e., the overall pendulum arrangement as well as the associated chime system, can be checked out for proper operation only when all of the separate parts of the pendulum have been assembled on the clockwork casing. There is, in addition, the disadvantage that the pendulum arm is substantially U-shaped and envelopes the clockwork laterally, and this requires a comparatively large amount of space for the swinging motion of the pendulum. The known arrangement, moreover, cannot be used in conjunction with comparatively small pendulum clocks, for example table clocks; and the lateral placement of the bell of the clock-striking system precludes use of the arrangement in small-sized classic clocks.
The present invention is intended to obviate these disadvantages of the prior art, and is concerned with a novel autonomous pendulum mechanism which can be connected to the casing of the clockwork in the form of a completely separate assembled structural unit whose functioning can be checked out independently of the clockwork. Moreover, the unitary pendulum mechanism of the present invention is so arranged that a chiming system can be incorporated therein as part of the pendulum unit, so that its proper operation can also be checked out independently of the clockwork.