Restoring a Winterhalder & Hofmeier 2-Train Quarter-Striking Clock

Restoring a Winterhalder & Hofmeier (W&H) 2-train movement requires a nuanced understanding of its unique quarter-striking mechanism. Experts suggest that these high-quality German movements often utilize a single hammer for the hour strike while signaling quarters with a "bim-bam" sequence. Restorers recommend paying close attention to the interplay between the minute wheel and the lifting levers, as minor misalignments in these components are the most common cause of strike failure.

Managing Strike Train Power and Volume

A common issue with spring-driven W&H movements is stalling three or four days after a full wind. Restorers suggest that this is often caused by excessive return spring pressure on the hammer arbors. When the mainspring torque decreases mid-week, the mechanism lacks the power to overcome tight return springs, especially when attempting to lift both hammers for the quarter strike.

To equalize the sound of the "bim-bam" strike, experts suggest adjusting the length of the lifting pins. Shortening a pin slightly can reduce the hammer lift, which not only balances the volume between the two gongs but also reduces the physical load on the strike train, helping to prevent mid-week stalling. Restorers also recommend ensuring all lifting pins are polished smooth on the lower side to prevent them from catching on the strike wheel pins.

Frequently Asked Questions

1. Why does my W&H clock stall mid-week despite being fully wound? Restorers often find that backing off the pressure on the hammer return springs allows the train to run even as mainspring power decreases.

2. What is a "Blind Man's Clock"? While often applied to any striking clock, experts clarify that a true blind man's clock uses a Grande Sonnerie strike, which counts the hour at every quarter point to allow the listener to know the exact time without looking.

3. How do I know if the "bim-bam" hammers are lifting too high? Repairers suggest that if the hammers hit the gong rods too hard or cause the train to stall during the dual-lift phase, the pins are likely too long and should be shortened.

4. What is the significance of the "W&H Sch." mark? This mark helps date the movement, typically appearing on high-quality movements from the mid-19th century through the early 20th century, often housed in rustic or English-style cases.

5. Should the hammer pin be in contact with the strike wheel when at rest? No, restorers suggest there should be a visible gap between the hammer pin and the strike wheel pins to allow the train a "run-up" after being released from warning.