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Gillett and Johnston Grandmother clock


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I picked up my latest project today, listed on Ebay yesterday as a Victorian Grandmother clock, The clock is certainly not Victorian it dates from 1924 this can be pinpointed quite accurately because it has a two train full Westminster strike movement utilising a locking differential gear although patent applied for in 1920 its first use by Gillett in a commercial clock was  around 1924, this clock movement is stamped with the Gillett and Johnston trademark, some time in 1924 F.W Elliott purchased Gillett and subsequent production was stamped Elliott.

I already own a couple of Gillett and Johnston two train Westminster clocks one a small spring driven platform escapement mantle clock and the other a twin fusee bracket clock, I have wanted one of the weight driven variety for a while but auction prices and dealer prices are too high for my pocket.

I took a gamble on the clock because the ebay listing gave scant details and poor pictures and the elderly seller could only say that the clock had been inherited many years ago from her aunt because no one else in the family had wanted it, but a few things helped make up my mind that the clock was a Gillet and Johnston, although the ebay listing did not show the pendulum it did show the flat pendulum rod, this is a very distinct feature of later Gillett clocks from around 1920 onwards which used a patented Invar self temperature compensating pendulum as seen in the picture I have taken below, the pendulum bob is a lead antimony alloy.

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The other clue to its maker is in the unsigned engraved dial, in nearly all engraved Gillett dials the motif is a basket of flowers in the central portion of the dial this features on longcase and bracket clocks they made and is considered as a unofficial trademark amongst collectors very few Gillett and Johnston dials of this period are signed because most of their production wasn't sold directly to the public, but through retail jewellers and a plaque featured on the dial for the retailer to engrave their company name onto, and any dial actually signed Gillett and Johnston would be unusual.

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The Movement is typical of Gillett and Johnston  production of the time being of high quality, with thick plates, deadbeat escapement, with beat adjustment on the crutch and maintaining power on the going train, the weights are of brass cased lead, the strike, chime weight is very heavy weighing 26 pounds, as with all two train Westminster they do require a lot of power to run.IMG_2978.thumb.JPG.c3266bb1716021da014b7097963652e8.JPG

The clock is very dirty and I shall be cleaning it some time soon so shall post pictures of the cleaning  and also explain how the two train striking system works.

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2 hours ago, wls1971 said:

The clock is very dirty and I shall be cleaning it some time soon so shall post pictures of the cleaning  and also explain how the two train striking system works.

I know nothing about clocks so I shall be looking forward to it.

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Very well made movement. With a dead beat escapement pity it doesn’t have a seconds hand so you can see how the dead beat works. With maintaining power and type of pendulum it should be a very good time keeper. A nice well made proportioned case. It certainly is one of the better Grandmother clocks that you see from that period.

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  • 2 weeks later...

I have now cleaned the movement of the clock and after being under test for a week it has been re instated into the case and just needs adjusting for time keeping over the next couple of weeks, the clock had very little wrong with it, minor wear to the pallets and a broken spring on the maintaining power ratchet.

below is a copy of the original patent application form:

https://patentimages.storage.googleapis.com/cb/23/0f/34b4fc44f86b51/US1468267.pdf

The main advantage for the use of two trains in a chiming clock was to simplify the servicing and Maintenance of the clock and reduce manufacturing costs it also allowed the movement to be much more compact than a traditional three train chiming clock of the period, although most of the mantle and bracket clocks made where in appearance no smaller than three train clocks of the time with the exception of some of the mantle clocks with platform escapement which where very compact in design.

The movement was best employed in the construction of Grandfather clocks with Tubular bells which before where very large and imposing in size, the compact design also made it practical to manufacture Grandmother clocks with tubular bells, having been recently shown a 9 tube grandmother clock by a collector that was even smaller than the rod chiming one I now own.

The key to the design is the ability to seamlessly split the drive between chime and strike, in order to do that the design has a two part contrate geared chime strike drum that allows the chime barrel to be locked and drive transferred to the strike via a differential gear as seen in the photos below:P1.thumb.jpg.8c73422110235086ae087951c390849e.jpg

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side view of movement with chime strike barrel in situe

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In order to lock and unlock the chime and strike a large V-shaped lever is used P3.thumb.jpg.fecaed8ed1e18d88814a7c69e0391468.jpg

 

When chiming the lever is pushed to the right by a spring this engages the lever with the striking wheel pins preventing it from running but allowing power to the chime drum.

The clock works in much the same way a Ting Tang type clock would it is fitted with a rack that has twin rack tails one for the quarter chime sequence and one for the hour chime/strike sequence which can only engage with the hour snail when a cut out section of the quarter snail is reached near the hour as shown below:

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In order to lock the chime and unlock the strike a tension spring is employed, this is connected to the V shape locking lever and is tensioned on the hour by a pin located on the quarter chime snail this pushes the  lever to the left but is prevented from moving by the rim of the chime barrel after a full 16 note chime sequence the lever engages with a slot on the chime barrel rim locking it, at the same time this disengages the lock on the strike and that begins to run striking the hours.

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At about 5 past the hour the pin on the snail releases tension on the spring and the V-shape lever is pushed out of the slot on the chime barrel and back on to the hour strike pins allowing once again quarter chiming.

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 Looks very good. What type of cleaning did you use? Nice to see the clean screws and blued as some should be. I not sure on the type of line you used? More likely its my eyesight.                                                                                                                                                                                                                                                                         

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40 minutes ago, oldhippy said:

 Looks very good. What type of cleaning did you use? Nice to see the clean screws and blued as some should be. I not sure on the type of line you used? More likely its my eyesight.                                                                                                                                                                                                                                                                         

I have used a clock cleaner by Priory Polishes, it is the same as Horolene but half the price, I avoided using any abrasive cleaners to preserve the finish on the plates, the line I have used is a vinyl coated multi strand steel line which I am going to replace, the chime train weight is very heavy so I have ordered a slightly thicker line, although the breaking strain of the line used is well within its range it does not fill me with confidence, when cleaning the clock I removed the old line and that had worn at the point of fixing to the winding barrel and had only about 4 strands of wire holding the weight up.

 

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I have heard of that cleaner, but never used it, it does a good job. Those lines have about 200 lb breaking strain if it fits in the barrel grooves and is a good fit, the other thing I like about that type of line is at the barrel end after making a knot you can heat the vinyl and it will mold so the knot will never slip or come undone. Those old wire lines unravel and mark the brass work, I always replaced them. 

One last thing does  that cleaner give of a pong? 

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The cleaner,  ammonia is a active ingredient so does smell , its about £18.00 per litre as apposed to £30.00  a litre for Horolene and I can detect no difference in cleaning performance, it is used at a ratio of one part cleaner to 7 parts water, just as Horolene is, I always buy it direct from their Ebay shop and get a 10ml J.D Windles clock oil thrown in.

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