Gilbert tambour clock with Normandy Chime – movement servicing

Gilbert mantel clock 1925

This Gilbert tambour style mantel clock is model 2038 with a bim-bam strike or what Gilbert called a Normandy chime. The model number along with the words “Normandy Chime” are stamped on the bottom of the case. Gilbert called this the “Normandy Chime” as it was reminiscent of the old bells of Normandy (Corneville) in France. In terms of nomenclature within clock circles, calling it a “Chime” certainly adds to the confusion as this would be considered a striking clock rather than a chiming one.

Whoever did the past bushing work chose to avoid the motion works area, and for good reason

The Movement

And now to service the movement.

Dis-assembly of the movement is done in the conventional manner with the exception of two items. Both the striking disk (upper arrow) which runs off the cam wheel and the passing strike L bracket (lower arrow) which runs off the centre cannon are friction fit and must be pulled off beforehand to work on the movement. I don’t have a puller but two small screwdrivers positioned across from each other will lift the parts off with minimal effort. Do not polish the ends of these two rear pivots.

Arrows showing striking disk and passing strike L bracket

A prior examination of the movement revealed that it is generally good shape. Overall, the lantern pinions are in good condition with minimal wear. There has been extensive bushing work completed in the past. I see six replacement bushings on the back plate and seven on the front for a total of thirteen which suggests that there was a lot of wear. They are all in very good condition which tells me that the work was done fairly recently.

It also tells me that whoever did the past bushing work chose to avoid the motion works area and for two reasons. It is a tough one to fix because there is so little brass to work with and there is not a lot of torque on this wheel so it can be left as-is.

Although the following photo does not show it well, there is a lot of play in the bushing hole. This is the only one that is addressed in this servicing because I wanted to ensure good meshing of the motion works gears.

Motion works gear with bushing wear

To address the motion works bushing I sought advice from my colleagues at the NAWCC forum site with comments ranging from doing nothing to immediate replacement. The best advice came from a member who suggested I install a smaller diameter bushing and broach out the hole to fit the pivot and that is exactly what I did. A #46 Bergeon bushing was chosen with a diameter of 3mm and an inside diameter of 1.30mm. The pivot is 1.48mm and the result is a side wall that is about 0.80mm. This should allow the gear to mesh nicely and since there is not a lot of torque on this gear the fix should last a long time.

Re-assembling was straightforward. There are no helper springs on this movement so there was no tension pushing on the levers. The only adjustment I had to make was to pull the movement slightly apart to correctly align the stop pin to the stop lever so that the movement strikes as it should.

Arrow showing stop pin (my healing thumbnail from a mainspring that let go)

Since the movement has a Normandy chime the striking hammers are located outside and to the bottom of the movement.

Striking hammer assembly for Normandy Chime

The final process in re-assembly is to attach the hammer mechanism. But before doing so two parts are re-attached, the strike wheel and the L bracket which are pushed back into place. Once in place they can be moved slightly to sync the hourly and half hour strike.

Some folks give Gilbert movements a bad rap but they are not much different than a Sessions, or similar inexpensive movement of that period and the fact that this one is still functioning after over 90 years has to say something for its engineering.