The Great Astronomical Clock 2011-2015

Description of operation

The clock drive (regulator) drives the seconds hand axis and the minute hand axis of the main mechanism. The main mechanism controls the movement of the hands visible on the main dial, in addition to the "sunrise", "sunset" and "sun declination" hands. It also controls the year indications in the four fields of the main dial.

The main mechanism acts as a complete calendar device. It does not have automatic date correction. The main mechanism drives the annual gear, via the transmission mechanism, at a speed of 1 revolution/24 hours, and the 'time zone' indication dial at the same speed.

The annual gear axis makes 1 revolution in 365 days. A speed of 1/365 days has been achieved by using a worm gear. The annual gear, in addition to the "season" and "zodiac signs” indication drive, controls the "sunrise", "sunset" and "sun declination" indications on the main dial via the transmission mechanism. If necessary, the date should be adjusted with the key from the toolkit provided with the clock. Once every four years, the clock should be stopped for 24 hours to maintain the correct indications of 'sunrise', 'sunset', 'sun declination', 'zodiac signs' and 'seasons'.

Interruptions in the operation of the timer result in the erroneous setting of the aforementioned functions and make it necessary to correct the setting.

Drive mechanism (regulator)

The clock mechanism is a modern design the size of a small tower clock. Ball bearings have been used for all axes of the mechanism due to the need to increase the durability of the mechanism and reduce rolling resistance. The pendulum and anchor have been fitted with two knife supports resting on the prism sockets of the mechanism. The anchor-pendulum connection has been equipped with a pendulum swing regulator and a safety device to protect the capture wheel and the pallets from damage in the event of a pulse failure. The seconds pendulum has thermal compensation. The mechanism has a cable tension, with a power reserve of approximately 5 days.

Transmission mechanism

The transmission mechanism, located between the drive (regulator) and the main mechanism, distributes the drive in multiple directions and planes via sprockets, Gall chains, and drive axles. Bodies with roller-bearing-mounted sprocket axles have been fixed on the mechanism plate. Each sprocket system has adjustable chain tension, and the drive axles are fitted with longitudinally sliding Cardan joints to protect the entire linkage system from additional rolling resistance. All structural components of the drive mechanism involved in the clock's operation have been heat-treated to increase the durability of the components.

Tensioning mechanism

In order to wind up the clock, a crank is applied to the quadrant of the winding axis. The axis of the tensioning mechanism is mounted to the wooden clock case by means of two brackets. An additional pair of sprockets makes it possible to reduce the force required to wind the clock up. The sprocket axles are housed in bodies fitted with ball bearings. By means of a Gall chain and a sprocket integrated into the axle of the clock drive mechanism's cable reel, wind the clock by turning the crank in the direction indicated by the arrows.

The main mechanism of Krzysztof Płonka's astronomical clock is a highly complex calendar device that controls all the clock's functions.

The central axis of the main mechanism makes 1 revolution per hour – this is the minute axis. Through gears with a gear ratio of 1 revolution/24 hour, the drive of the date display, days of the week, moon phase, GMT time indications – (24-hour dial), globe drive, time zone drive, and worm annual gear drive have been obtained. A gear system with a ratio of 1 revolution/12 hours drives the hour hand.

The year indication mechanism located in the four fields of the dial consists of four rotating drums with the numerals 0 to 9. The mechanism automatically changes the year when the month name is changed to January. The mechanical counter changes the display automatically for 99 years. After this period, the settings in the fields on the left-hand side of the dial should be adjusted manually. Each time the year changes, the setting of the indicator on the dial changes – "ordinary years – leap year".

The main mechanism drives the annual gearbox at a rate of 1 revolution/365 days. The drive works by means of gear wheels of the main mechanism, chain gears of the drive transmission mechanism and a worm gear. The annual gearbox is responsible for the indications – 'seasons', 'zodiac signs', 'sunrise', 'sunset', and 'sun declination'. The above indications have been obtained with gears, levers, and cams making one revolution in 365 days. The system needs to be revised every 4 years.

Krzysztof Płonka

He was born in 1952 in Ślemień near Żywiec, where he lived and attended primary school. In 1966, he began studying mechanical engineering, machining and precision mechanics in Bielsko-Biała. He has been self-employed since 1990. Since the beginning of his career, clock constructions have become his lifelong passion.

It deepens the knowledge of the history and construction of mechanical clocks, and at the same time rebuilds unique, antique clocks, restoring them to all functions, which allows them to operate.

In 2005, he obtained a patent for the "Chronometer Clock Grab" No. 204808, which he designed.

During this time, he begins building astronomical clocks of very high complication and "Regulator" type standing clocks.

Currently, he is working on the implementation of Krzysztof Płonka's "Great Astronomical, Figural Tower Clock" and rescues old, antique mechanical clocks from total oblivion by restoring their utility functions.

Project