Edward Stewart's time lock, Fort Madison, Iowa - 2 movements

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Minor repairs.

As received, the two cranks were frozen. An inspection revealed that the chain pulley and ratchet components had been improperly reassembled. The two larger oval areas show the blued steel ratchet springs sandwiched between the ratchet wheel and adjoining drive pulley. The ratchet must be astride the ratchet wheel. Being sandwiched in between would not allow the top securing plate to properly seat upon the pulley arbor causing the gaps as seen in the smaller circles. Screwing down the top plate simply squeezed the pulley, ratchet and ratchet wheels together causing the entire set to seize.

 

Two more photos of the ratchets misaligned on both pulleys.

Here I begin disassembly of the two drive chains and four pulleys. In the first photo they are still in place but with the top decorative name plate removed. Next one set is removed with one remaining and next the both sets removed.

 

The first photo shows a pulley with attached ratchet. The black circle is drawn on the photo to show the diameter of the ratchet wheel that would be adjacent to the ratchet. One can readily see a portion of the ratchet intersects the circle and will do so because it is spring tentioned to ride upon the face of the ratchet wheel. The second photo shows this same condition on both pulleys, arrows 1 and 2. Arrows three and four show the attachments on the chain that control the bolt dog release (3) and the cycling of the day on the calendar wheel (4).

 

The chain was very stiff making the rotation of the hand cranks difficult. Each link was inspected, oiled and manipulated until each link was free to move independently from its neighbor. Next a thin metal strip is used to position each ratchet during reassembly so as to move it out of the way of the ratchet wheel face allowing for all components to be properly alligned.

 

The chain, pulley components are now reinstalled. next a photo of the case serial number 1.

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