The Ansonia 5-Pillar Shelf Clock Movement, ca. 1885

September 11, 2012 | By | Reply More

This is the Ansonia 5-pillar shelf clock movement. It strikes the hours, and is nominally an 8-day movement, although it will usually run close to 2 weeks on one winding. The plates of the movement are 5 3/4 inches tall and 3 5/16 inches wide. 5 steel pillars secure the front plate to the back plate.

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Many Ansonia shelf clocks from the 1880s have this movement. In the late 1880s or early 1890s, the smaller 4-pillar movement superseded this 5-pillar movement.

The 5-pillar movement has a between the plates recoil escapement using an American-style strip verge (also called the anchor). It has the “count wheel” strike system that requires manual correction if the striking gets out of sync with the hands.

Correcting the Strike

Some clocks have a wire hanging below the dial, near the 7. Push up on the wire from the bottom and release it. The clock will strike the next hour. Do this until the striking is correct.

If there is no wire, use the following procedure:

  • Move the minute hand (long hand) forward (clockwise), stopping about 5 minutes before the hour, when the clock makes a striking preparation noise called “warning”.
  • Move the minute hand backward (counterclockwise) to 25 minutes before the hour. This will cause the clock to strike the hour.
  • Repeat above two steps until the clock strikes one hour less than the hour that the hour hand points to.
  • Move the minute hand forward, pausing at each hour for the clock to strike, and set the clock to the correct time.

There is also a “cheater’s method” for correcting the strike:

  • Move the minute hand to the next hour (the clock will strike),
  • Grasp the hour hand (short hand) near the center and move it around to the hour that the clock just struck. (if the hour hand get loose, push it onto its shaft, using your thumbnails to push in at the center). Note: if the hour hand is too tight to move easily, don’t use this method).
  • Use the minute hand to set the clock to the correct time, pausing each hour for the clock to strike.

Mainsprings

The 5-pillar movement has 3/4 inch wide mainsprings with loop outer end. They are “open” springs (they are out in the open and not contained in barrels). The original mainsprings are rougher than modern springs, and the loop ends are “rolled” instead of riveted. Note to repairers: The keep the original springs in the movement if they have no obvious damage.

If a mainspring needs replacing, I recommend a spring 0.0165 inch thick or less. Don’t use the so-called standard American clock mainspring of 0.0175 – 0.018 inch thick, it is too strong and will result in wear to the mainwheel teeth. I have had excellent results with a loop end mainspring 3/4 wide by 0.0165 inch thick by 120 inches long, such as the 77.303 from R & M Imports or the Timesavers 15959.

Example Clock

The clock illustrated above is the “La Mascotte” , made around 1883 according to the book “Ansonia Clocks” by Tran Duy Ly. I first repaired this example in 2002. I polished the pivots, installed 18 bushings, re-pinned 4 pinions and polished the verge faces. At that time it  had a non-original time mainspring 3/4 by 0.0178 inch thick, and had the original strike mainspring, a rough spring with rolled loop end, 0.0167 inch thick.

In 2012, the clock came into my shop again, with a broken strike mainspring. After cleaning, I observed that the time spring was causing wear to the mainwheel teeth, thus I decided to replace both springs. I selected two springs no. 77.303 from R & M Imports. These are specified as 3/4 by 0.0165 by 120 inches long. Actual measured thicknesses are 0.0157 inch for the time spring and 0.0163 inch for the strike spring. The clock runs very well with these springs, and even thinner springs could be used.

The pivots I had polished in 2002 had caused no wear to their bushings in the 10 years of operation. I hadn’t polished the front strike 3rd wheel pivot in 2002, and its bushing had worn. Thus I polished that pivot this time, and installed a new bushing. No other repair work was needed.

Repair job 5871.


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Category: American Clock Mainsprings, American Clock Repair

Last updated: October 11, 2012

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