The conical pendulum was first described by Hooke in the 1660's and made its appearance in clocks in the 1800's. Because it is a continuous motion system rather than the stop start motion of a traditional escapement it was used for the control of the sweeping of lighthouse beams and astronomical telescopes. From 1860 Eugene Farcot produced a number of elegant timekeepers employing conical pendulums.
Perhaps surprisingly the frequency of rotation of a conical pendulum follows the same equation as a traditional pendulum and depends only on the its length and gravitational force.For small angles of cone the pendulum is independent of the driving force and is thus isochronous.
My version of a conical pendulum clock represents a Cornish beam engine and the case is dressed in images relating to tin mining.
This is a true pendulum clock in that the pendulum is doing the regulating and its frequency is adjusted by altering its length. Coarse adjustment is made by raising or lowering the beam and fine adjustment by an adjustable screw at the nose of the beam. The length of the cotton thread is then adjusted and held by a pair of wooden cheek pieces.
The going train of the clock is weight driven by a very small weight (50 gramme) that is rewound every 45 secs or so by an electric motor driving a differential system. This mechanism can be seen in the video below. The design of this remontoire is ascribed to Augustine Lepaute c. 1830 and has been used in a number of tower clocks. for further information see http://www.my-time-machines.net/korfhage_remontore.htm
As in some of my other clocks I use a microcontroller to control the speed and duration of the winding after the descending weight has triggered an electrical contact
Because of the way that the differential works power to the going train is maintained during winding.
The challenge was to produce wooden bevel gears for the differential and although I did make proper bevel gears on the band saw in the long run it was easier to use modified spur gears. A similar pair of bevel/spur gears is used in the final right angle drive to the pendulum drive.
Thanks for sharing about Pendulum Clock. You Content is really informative us.......
ReplyDeletePendulum Clock
Pendulum Wall Clock