A Ting-Tang Yorkshire Long-Case
An interesting long-case clock passed through my workshop not too long ago, It was a painted dial, West Yorkshire clock of the late 18th century. The interesting feature was its mechanism for chiming the quarters, using a specially designed inside count-wheel.
The maker is James Booth, son of Benjamin Booth C1780.
This clock chimes Ting-Tang quarters, that is sounding on two bells, first the higher, then the lower. Repeating this for the number of quarters that have passed.
The driving weight for the quarter chiming and strike train is a 20lb weight, extremely big for a long-case clock, but sufficient for driving this more complicated gear train. the time train weight is14lb.
Beneath the dial we can see how the mechanism works, and I will take a minute to explain its main features, with the aid of pictures.
When striking, the pin wheel lifts the deeper toned hammer to cause it to strike the bell when dropped. The attached dark blue lever is therefore also lifted and acts upon the light blue lever, lifting it too.
Because the light blue lever is significantly shorter, it drops first, causing the 'Ting'. Shortly after that, the deeper bell sounds as the hammer tail drops from the pin wheel (Tang)
Once an hour, the cannon lever presses the light blue hammer tail towards the plate and therefore away from the dark blue lever, in this manner the hour can be struck on a single bell.
The design of the count-wheel is unique, you can see from the picture to the left that it is numerical as usual, one o'clock being on the right hand side in this image. However the sequence is interrupted by notches to allow the correct number of Ting-tangs to be struck. Note also the larger than usual size of the great wheel to allow for the extra duration needed to strike at every quarter.
This is the under dial work. I have used colour to make my explanation easier to understand.
In the red circle we can see the minute wheel, its job is to convert the cannon wheel's one rotation per hour, to the hour wheel's one rotation every 12 hours. This minute wheel has four lifters (Pins) to set the strike train off at every quarter. These lifters act in the usual manner to set-off the count wheel striking mechanism.
In the green wheel we can see a ramp attached to the cannon wheel, This wheel drives the minute hand. This ramp therefore acts on its associated lever (referred to here as the cannon lever) once every hour.
The light blue line represents the hammer tail of the higher pitched bell, the dark blue lever is attached to the deeper bell. The hammer tail on the deeper bell operates in the usual manner on the pin wheel.
Ting-Tang Position of Levers
Striking Position of Levers