Due to the complexity and the number of images available I shall split discussion of the mechanism into several parts. The first will discuss and illustrate the switching involved in starting and ending the striking sequence:
Rather than repeat the sequence of actions, word for word, here is an earlier post describing an earlier bell striker.
A general view is seen here of the bell striker from the front. The drive motor is on the far left. The main worm, its wormwheel and snail-shaped, hammer lifting cam are raised high on a sturdy bracket in the centre rear of the mechanism. The round, count plate, with slots in its periphery, limits the number of strikes each hour and is seen in the centre foreground. I will discuss its drive and how it functions in a later part.
The linkage on the extreme right would be connected to a bell hammer pull wire or rope. Note that the long, black, hammer lifting lever is quite separate from the white switching lever in the foreground. The black, bell striking lever is pushed down and released by the large, snail-shaped cam in the centre when the motor runs. The black striking lever is hinged just in front of the drive motor.
The actual switches or contacts used varied over the history of Gents' bell striker mechanisms. Their purpose remains the same. A microswitch was used in some bell strikers to turn the drive motor on and off. There appears to be a box above the switching arm's pivot. Which may contain the switch for the drive motor.
Note also the shiny, steel, stepped latch on the right and the strangely twisted arm just to the left of the height adjusting screw. At rest, between striking sequences, the switching lever is normally raised and unlatched. The latch is connected [in a continuous U-shape] to the twisted metal arm. A brass leaf spring presses upwards against the base of the U-shaped lever/latch. Ensuring that the lever will latch itself via its long pin when it falls far enough.
Rotation of the main wormwheel and cam shaft also rotates a trip vane clamped to the same shaft. When this long metal arm strikes the top of the U-shaped arm the switching lever is unlatched. Due to the counterweight the switching lever can now rise again. The contacts above the counterweight open and the motor shaft brake is instantly re-applied.
Usually a separate timing device [known as a bell ringer] is driven by the controlling master clock of the entire clock system. The bell ringer sends out an electrical signal every hour on the hour.
The terminals for the low voltage, timing signal and brake solenoid are fixed on two insulated blocks at the front of the massive, cast iron, bed plate.
N.B. There is no connection between the low voltage wiring and the 250V mains electricity which drives the electric motor.
WARNING: Connecting these low voltage terminals to the mains electricity would immediately destroy the electromagnets. Very probably causing a dangerous fire! Exposed, bare metal parts would be very likely to carry a lethal mains voltage! Even if you survived, the bell striking mechanism and its entire clock system would probably be completely destroyed! Fires might even occur throughout the building! You have been warned! Low voltages only to be connected to these bare terminals.