Chiming mechanisms make it possible to hear the time. They pose great challenges for watchmakers: The gongs need enough room for oscillating while the striking mechanism consumes part of the timepiece’s energy.
THE STRIKING MECHANISMS OF THE ZEITWERK WATCH FAMILY
VISIBLE PRE-STRIKE COCKING
The mainspring barrel of the ZEITWERK delivers the ample power needed to advance the numeral discs. In the ZEITWERK STRIKING TIME and the ZEITWERK DECIMAL STRIKE HONEYGOLD, a part of this energy is used to power the striking mechanism. Every time a numeral disc advances, the hammer that will execute the next strike visibly moves up a fraction of the way toward the centre of the watch. This gradually tensions the spring that triggers the impact of the hammer against the gong.
The striking mechanism of the ZEITWERK STRIKING TIME is activated by a three-pronged snail (1). The three prongs control the mechanism of the quarter-hour hammer (2a) on the right-hand side. Below it lies a fourth prong for the hour hammer (2b) on the left-hand side. Powered by the switching impulses of the jumping numerals mechanism, the snail rotates about its own axis by 60 small steps in the course of an hour. During this phase, one of the four prongs deflects its hammer via a lever (3a, 3b), thus tensioning its respective spring. Precisely every quarter-hour and hour, the respective lever crosses over the apex of its prong and allows the spring to trip the hammer against its gong (4a, 4b).
The ZEITWERK DECIMAL STRIKE HONEYGOLD features a five-pronged snail instead of the three-pronged version. It assures that the right-hand hammer strikes five instead of three times: at 10, 20, 30, 40 and 50 minutes. At 60 minutes, i.e. at the top of the hour, the strike is executed by the hour hammer.