Striking

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I removed the DUFA's hands and dial.


Which leaves the front plate showing the motion works (the parts that turn the hands). You can see that this movement also uses a rack & snail for its striking. When the rack is activated it starts things turning in the back of the clock.


Here is a rear view of the movement showing the hammers on the strike. They are attached to arbors that turn as part of the strike. When the clock strikes those arbors turn, lifting the hammers, and then they release the lift such that the hammers drop and strike the gong rods in the case.


Here you can see how the hammers are all connected to a cylinder that is screwed onto an arbor. The left set has been removed from their arbor in the photo below.


So...

How does that lifting of the hammers actually happen?

The rack and snail determines how many times the clock should strike. 

When the rack and snail are activated the strike train turns the pin wheel (seen below) counterclockwise. As it the pin wheel rotates, a pin (here Pin A) will catch and pull the Lifting lever A to the right (it pivots on its own arbor on the bottom). As Lifting lever A is pulled right its far left end catches Lifting Rod A and as it is pulled upwards, it turns the arbor counterclockwise. The rotation of the arbor lifts the hammers on the right up and away from the gong rods.


As the Pin wheel continues to rotate, Pin A will travel past its contact point with Lifting lever A, which will slip its contact with Pin A and the lever will fall back to the left. Lifting Rod A will drop. The right hammers will fall.

As the Pin wheel continues its rotation, Pin B will contact Lifting lever B. In this case it pushes that lever downwards, seesawing the left side of Lifting lever B up, which connects to and then raises Lifting rod B, turning the left arbor clockwise.


Just as with the right side, as the Pin wheel continues its rotation Pin B will slip its contact with Lifting lever B which will slip and fall, allowing Lifting rod B to fall and the left hammers to drop, striking the left gong rods in the case.

That constitutes one full strike.

The pin wheel continues for as many strikes as set by the rack and snail.

Here it is all demonstrated with a video. 

And yes this is another "after" video when I was rebuilding the movement after cleaning and setting the strike back together. Click on full screen.


I'll stop here but I'm going to come back to one very important, and wonderful feature of this movement.

When the hammers fall, how to they fall just enough to hit the rods but not stay in contact with them?

It's way more complicated than you might think.


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