Inspecting minute repeater with chrono function

Reviewed by Andrew Babanin

At Moscow flea market I found one interesting movement. To pity its in a poor condition: there's no case, some parts are broken, some missed. It's an old Invicta watch of the beginning of twentieth century.

What interested me in this movement? It's nice chronograph with minute repeater. I cleaned it carefully and fixed some small problems. Watch function works perfectly,as to chrono function - it works theoretically. "Theoretically" means, that if you rotate column wheel - chrono starts, stops and resets. But there's no lever to rotate it. I will try to find missed clicker and broken spring. As to repeater - here more problems. A spring is broken, there are no strings, some parts under the dial are missed. But anyway you can notice how complex this movement is.

Repeater centrifugal governor (wheel with maltese cross) has two weights. It slows down gongs. Under centrifugal forces they move apart, but small springs return them back.

You can notice that it's quite spacy under the dial (I didn't photograph it because it's not interesting). In some watches you can find full calendar with moon phase. This one didn't have such complications. To pity cannon pinion and hour wheels are missed. But still you can notice brass wheel with sharp teeth. There're 12 teeth. Underneath it has a plate of spiral shape with steps. The bottom raker interacts with it and knows about hours.

The upper raker interfered with cannon pinion. There're 14 teeth for minutes. On the fifteen there'll be a strike - a quarter. So these two rakers by means special levers affect on cams and make them striking the strings.

On disassembling I found that it's quite common to watchmaking society Landeron movement: "Hahn Landeron". You can notice a raker with sqare - it's the end of repeater spring arbor. You can also notice a gear - the bottom raker interacts with the push lever. By pressing on it you wind repeater module and it strikes present time.

I dismounted repeater bridges just to show you its spring.

In conclusion I wanna mention that working on such movements is a great pleasure. I still cannot believe that it was possible to make such complicated movements a century ago.