25/08/2023
Escapements - Electromechanical Escapements - Hipp
Hipp Clock
In the middle of the 19th century Matthias Hipp invented a switch for a clock which was impulsed electro-magnetically. The pendulum drove a ratchet wheel via a pawl on the pendulum rod and the ratchet wheel drove the rest of the clock train to indicate the time. The pendulum was not impulsed on every swing or even at a set interval of time. It was only impulsed when its arc of swing had decayed below a certain level. As well as the counting pawl, the pendulum carried a small vane, known as a Hipp's toggle, pivoted at the top, which was completely free to swing. It was placed so that it dragged across a triangular polished block with a vee-groove in the top of it. When the arc of swing of the pendulum was large enough, the vane crossed the groove and swung free on the other side. If the arc was too small the vane never left the far side of the groove, and when the pendulum swung back it pushed the block strongly downwards. The block carried a contact which completed the circuit to the electromagnet which impulsed the pendulum. The pendulum was only impulsed as it required it.
This type of clock was widely used as a master clock in large buildings to control numerous slave clocks. Most telephone exchanges used such a clock to control timed events such as were needed to control the set up and charging of telephone calls by issuing pulses of varying durations such as every second, six seconds and so on.
An interesting read, have one myself in the workshop
Synchronomes Gents, Gensigns, & CBH Master Clocks and Others