Overview of the Count‑Wheel Strike System
The American count‑wheel strike system uses a coordinated set of levers, wheels, and cams to control when the clock strikes, how many times it strikes, and when the strike train stops. The system remains at rest until activated by the minute arbor pin, which lifts the J‑hook and begins the strike sequence.
How the Strike Train Rests
Count lever position
The count lever rests in a deep slot on the count wheel when the strike train is inactive.
Maintenance lever position
The maintenance lever sits in one of the slots on the maintenance cam.
Warning wheel lever position
The warning wheel lever arrests the warning pin, preventing the train from moving.
J‑hook position
The J‑hook rests against the brass lever, which is held in place by the pin on the minute arbor.
How the Lift Lever and J‑Hook Interact
Minute arbor pin movement
The pin on the minute arbor pushes the brass lever forward as the minute hand approaches the hour.
J‑hook lift
The brass lever lifts the J‑hook, which in turn raises the count lever and maintenance lever.
Approaching release
As the J‑hook rises, the count lever begins to lift out of the deep slot on the count wheel.
Entering Warning
Count lever rising
The count lever lifts almost out of the deep slot but does not yet release the train.
Maintenance lever rising
The maintenance lever rises within the slot on the maintenance cam.
Warning wheel lever rising
The warning wheel lever slides up the warning pin, preparing for release.
Strike Release
J‑hook disengagement
The brass lever moves far enough to disengage the J‑hook completely.
Count lever clears the deep slot
The count lever rises onto the raised section of the count wheel.
Maintenance cam rotation begins
The maintenance lever lifts out of its slot, allowing the cam to turn.
Warning wheel release
The warning wheel lever lifts above the warning pin, allowing the strike train to run.
How the Strike Train Operates
Count wheel control
The count lever rides along the raised section of the count wheel, determining how many strikes occur.
Maintenance cam control
The maintenance cam lifts and drops the hammer lever, producing each strike.
Hammer action
The hammer lever rides up a pin on the maintenance cam and drops off, striking the gong.
Hammer return
The hammer return spring brings the hammer back to its resting position after each strike.
Ending the Strike Sequence
Count lever drop
When the count lever reaches the next deep slot, it drops into place.
Maintenance lever drop
The maintenance lever drops into a slot on the maintenance cam, stopping its rotation.
Warning wheel arrest
The warning wheel lever drops and arrests the warning pin, stopping the train.
Strike train at rest
The system remains at rest until the minute arbor pin lifts the brass lever again at the next hour.
Common Mistakes
Incorrect J‑hook height, misaligned warning pin, improper count lever position, or maintenance cam not seated in a slot at rest.
Troubleshooting
Strike runs continuously
The count lever is not dropping into a deep slot on the count wheel.
Strike stops too early
The maintenance lever is dropping into a slot prematurely.
Strike fails to start
The warning wheel pin is not clearing the warning lever during lift.
Hammer does not strike
The hammer lever is not engaging the pins on the maintenance cam.
FAQs
What controls the number of strikes?
The count wheel determines how many times the clock strikes by controlling when the count lever drops into a deep slot.
What starts the strike train?
The minute arbor pin lifts the brass lever, which raises the J‑hook and releases the strike train.
What stops the strike train?
The count lever drops into a deep slot, and the warning wheel lever arrests the warning pin.
Why does the hammer strike multiple times?
The maintenance cam lifts and drops the hammer lever for each strike.
Why does the strike fail to release?
The warning wheel pin may not be clearing the warning lever during lift.
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