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.

Tick Talk Tuesday #14 – Can you tell me something about my Forestville clock

Tick-Talk Tuesday is about the letters and comments I have received from you, the reader, concerning your clock, issues you might have had, challenges you face or a clock you would like me to profile and my responses to your questions with advice on your particular clock concern. For those comments and questions that stump even me, I consult within my clock circles for the best possible answer.
GGs Forestville Mantel clock
GGs Forestville Mantel clock

GG writes: “Hello there,,,I was wondering if you know much about my mantle clock and maybe it’s value?

I have attached some photos!”

My reply: “Thanks for coming to my blog. That is one of the nicest mantel clock cases I have seen on a Forestville and it appears to be in good shape.

Forestville is a Canadian Company based out of Toronto. They went out of business in 1979. They did not make their own movements instead sourcing them from England, France, the US and Germany though they made their own clock cases.

GGs clock showing German made movement and pendulum bob
GGs clock showing German made movement and pendulum bob

You may or may not know that Forestville was called the Blackforest Clock company prior to WWII. So, you have a post war clock made in the late 1940s or early 50s. Later on In the 1950s Forestville went from using pendulums in their clocks to balance wheels (no pendulum). Forestville also sourced German movements exclusively after the war. Your movement (the brass works) was likely made by Mauthe or Hermle, both well known and well respected German companies.

You have what is known as a time and strike Bim-Bam clock. It strikes the respective hour and once on the half hour but makes a distinctive “Bim-Bam” sound as a result of one hammer striking one rod while the other two strikes two rods simultaneously.

Unfortunately there are thousands of similar clocks and Forestville clocks are not particularly distinctive but a clock such as this in good running condition might fetch about $100.”

GG writes back to explain that the movement is an Enfield from England which stands to reason if it was made immediately after the Second War.

More fascinating terms – the language of clocks

Regular reader and contributor JC suggested a few more clock terms I thought readers and fellow horologists might find interesting.

My source for this article is the Watch and Clock Encyclopedia by Donald de Clarke, published by Bonanza Books (1984) which is still available on Amazon.

Gridiron pendulum: A pendulum consisting of alternating steels and brass rods coupled together to compensate for downward expansion so that the centre of oscillation of the pendulum remains consistent with changes in temperature, invented by John Harrison in 1725.

final look
Gridiron pendulum on a Junghans Crispi wall clock

Broaches: To broach is to open and enlarge a hole. A Broach is a steel cutting or smoothing tool with a tapered or parallel sided edge used to cut or “finish” holes in a clock plate. Used to enlarge and then finish (smooth) a newly installed bushing on a clock plate.

Swiss made smoothing broaches
A set of Swiss made smoothing (or finishing) broaches

Motion Works: The train or wheels of a clock directly connected with the hour and minute hand.

Great wheel: The teeth that form part of the barrel of the going barrel. It is also the wheel to which the mainspring is attached.

The motion works of a clock; the largest wheel on this movement is the great wheel (Pequegnat Clock Co.)

Maintaining Power: A method to maintain the driving power while the weight is being lifted or mainspring with fusee is being wound. In effect keeping the mechanism going while winding.

Weight driven movement with maintaining power
Weight driven movement with maintaining power, (unmarked Vienna Regulator)

Huygens Endless Rope Drive: It is a method of providing maintaining power to drive the clock while the weight was being raised. The endless cord passes over pulley A which is attached to the great wheel and supports the driving weight B, it then passes over pulley C which has a ratchet to support small weight D. As cord E is pulled down to wind the clock ratchet C turns under it’s click to raise weight B which continues to drive the clock as it supplies torque to wheel A. This ingenious system is found in some 18th century long-case clocks.

Huygens endless rope
Huygens endless rope

Locking Wheel (or Count Wheel): A count wheel is the wheel that determines the number of blows to be struck in striking mechanisms.

The left wheel with notches is the count wheel

Ratchet wheel: A toothed wheel into which a click engages permitting the wheel to revolve in one direction only.

Click replaced
Toothed ratchet wheel and click

Cam: Usually a disk so that upon revolving it transmits movement to or exerts pressure upon a connecting unit.

Arrow showing location of a cam
Arrow showing location of a cam, the fly is located in the upper right

Fly: Often called the governor or controller of a chime or strike train. It is the last piece in a train of wheels.

The language of the clock world always amazes me. There are a plethora of other clock terms that I will be happy to explore in future blogs.

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