Clocks & Pocket Watches

[Bernd]

Jere,

Here are the pics of that pocket watch I have.

The first is of the face. There are no markings on the face other than the numbers for the time. It could be that the face was replaced at some time. I believe the material to be porcelain. Note also that it has a winding key.



This is the part that gets me. The fine intricate marking. It doesn't look engraved. It looks more like it was etched. I believe it's 10 jewel movement. As you can seen it has two square posts, one for the main spring and one for the setting of the hands.



Note that there is another hinged cover. This had a piece of plastic in it when I got the watch. I am assuming it must have had a crystal in it at one time. Also the key is on the main spring.



Here's a bad picture of the only inscription I can find on the watch. It looks oriental to me.



I did finally get a better pic of the inscription and a number at the very bottom, 1438



That's about all I can tell of the watch other than I got it at a clock auction and it does run. The size of the watch is 62.25mm (2.450") in dia. and 11.4mm (.450") thickness.

Here are a few more pics of some of the wife's clock collection.

4 pocket watches, 2 small clocks, a small version on the right of a mission clock. Then there is the bird in the cage clock. This is rather a novel piece. It has a bird the moves back and forth. A small ball with a time scale and pointer tell the time.



5 carriage clocks and two novelty clocks



Atmos clock with round face.



Atmos with square face and crystal regulator.



Dent 8 day skeleton clock



And a time stamp clock. This clock was used to stamp your time clock. Still works.



What's it like a noon and mid-night around here? Really can't tell you. I've gotten used to the noise.

Bernd

[raynerd]

Really like the Dent 8 day skeleton clock. If you find time, could you post a few more pictures of it.

[Jere]

Bernd,

Your watch is of the type commonly referred to as "Chinese market watches."  They were made in Switzerland for sale in China in the 1800's.  They were typically ornately engraved as is yours.  For a very complete discussion of this type of watch, visit the following website : http://www.rawbw.com/~hbv/horology/chinese.html

I agree on the skeleton clock, I am always attracted to this type as well.  They are very popular among amateur clockmakers, I even got a book on how to make one, for someday in the future.  John Wilding's book "The Construction of an Elegant Scroll Frame Skeleton Clock."  An image of the clock he shows how to make, it is quite similar to yours.

[Bernd]

Thanks Jere. That is the first info I have ever gotten on this watch. I'll check out the site you provided.

A few years ago Bill Smith of clock fame wrote an article in, I believe it was Home Shop Machinist on building a skeleton clock. I know your interrested, right? I'll start digging out the issues. 

Thanks again.

Bernd

[Bernd]

Really like the Dent 8 day skeleton clock. If you find time, could you post a few more pictures of it.

More pics coming. Stay tuned.  

Here's a link to Bill Smith's clock page. http://www.wrsmithclocks.com/books.htm  Go down about half way for the skeleton wall clocks.

Bernd

[raynerd]

Jere, Bernd

When I was selecting which clock I wish to make, or at least slowly start, it was down to John Wildings - The Construction of an Elegant Scroll Frame Skeleton Clock and Colin Thornes - Skeleton Timepiece. I decided upon Thornes's as it does not have a strike as Wildings does, therefore presumed it would be a little easier or at least have fewer complications to the build.

Bernd - is it not John Wildings skeleton that is in home shop machinest or perhaps it may have been model engineer? I thought most of Wildings books were actually based on magasine articles rather than specifically for books. I could be totally wrong.

The disadvantage of Thornes skeleton clock is that it is plans only with no documentation of a possible build. I have recently purchased Thorne's "Clockmaking for the Model Engineer" which in my opinion, goes through all the methods of making parts for a simple clock. I purchased Wilding's book on his Gearless Clock many years ago and it seemed overly specific to a build on the Myford 7.

Bernd - I would like to see more pics of that clock as I really do like it and I could possible get some ideas for mine for the asthetics.

Regards
Chris 

[Jere]

Wilding's books, at least the ones I have, appear to be the compilations of the articles that were published in magazines.

[Krown Kustoms]

Bernd, you and your wife have a nice collection.
I hope this is not too far off topic, but this has been on my to do list for some time and would look nice sitting next to your skeleton clock.
http://www.model-engineer.co.uk/news/article.asp?a=5134
-B-

[Bernd]

-B-

Your more than welcome to build it and send it to the wife to set next to her clock.  I'm sure she would appreciate it.

And it's right on topic. Thanks for posting that link. I'm going to download the article.

Bernd

[Bernd]

Chris,

If you follow the link I gave to Bill Smith's web site you'll see the following

"How to Make a Skeleton Wall Clock" is comprised of twelve chapters which originally appeared in serial form in the "Home Shop Machinist" from Nov.1993 through Oct. 1995. There are 85 pages of text, and 280 photos and drawings."

So yes he did do a write up and now has it in book form.

Pictures of the Dent will be posted in the next day or so.

Bernd

[Bernd]

Here ya go Chris. More pics.



















Hope you like 'em.

Bernd

[raynerd]

Hi Bernd
Thanks for the extra pics it has given me some ideas. I really like that - how long have you had this clock?

[Darren]

Guys,

Without studying the concept, call me lazy if you like but I'm studying and researching so many other things at the mo. How does a time device keep accurate time.

I assume a spring is the motor, but how is it regulated?

[raynerd]

The power can be either a spring or simply a hanging weight. In a mechanical clock, the escapement and pendulum keep the "time". Hugely simplyfying, the escape wheel is a wheel with teeth cut differently to the norm, there is normally a pallet which inteferes with the teeth on the escapement. The pallet is attached to the pendulum which allows the wheel to be released one tooth at a time - tick and tock! the image below is a recoil escapement but you can get deadbeats, in which you do not see the recoil.



there are various ways of regulating the escapement to complicate things! This is a grasshopper:



It is the pendulum that is regulating it or a balance in the case of watches and some clocks:


Chris

[Darren]

Thanks Chris,

I suppose it's the energy of the falling weight that keeps the pendulums momentum from coming to a halt.

But what regulates each release of movement  (time wise)

[Darren]

Ah, so you mean it's the time between swinging from left to right that regulates time.

How is that controlled to alter the rate, thus accuracy?

[raynerd]

Thanks Chris,

I suppose it's the energy of the falling weight that keeps the pendulums momentum from coming to a halt.

But what regulates each release of movement  (time wise)

The escape wheel teeth are cut cleverly to give the pendulum a little "push" as it releases the wheel! It is really clever, if it didn`t, friction  would eventually grind it to a halt. As the pallet disengages with the escape wheel, the "power" or drive from the motion train gives the pallet a little push which in turn keeps the pendulm moving.

What regulates the movement

-   as the pendulum goes to one side, the pallet releases a tooth and moves around a little, the pendulum swings back and engages the pallet back and stops the escape wheel. And so it continues. The rate at which the pendulum swings dictates the release of the escape wheel and timing of the clock. Since the equation for the period of pendulum only really involve length and not mass, the wheel ratio is based on the length of the pendulum as this is going to ultimately dictate the release of the escape wheel and hence the time.

Chris

[raynerd]

Ah, so you mean it's the time between swinging from left to right that regulates time.

How is that controlled to alter the rate, thus accuracy?

There are few ways of regulating the clock but really it is due to the length of the pendulum. And we are talking about small amounts. The pendulum can be moved slightly up and down on the clock to change the period and therefore the time. Thats is why before I said that you need to take into account the gear ration when selecting the pendulum length or vice versa! Say you want gear ratio X for your mantle clock but that requires a 1m long pendulum, it is no use but in a longcase clock it would be fine for the gear train! The gear ratio needs to be selected to suit to pendulum length OR you can add to the motion train to gear the ratio down to suit. But this adds more wheels, more friction etc etc.
There are tables which say the ideals or suggestions and many clock use similar motion trains and ratios.

Chris

[Darren]

So to adjust the speed you adjust the length of the pendulum?

[raynerd]

yes, because the pendulum is attached to the pallets, the pallet regulates how fast the escape wheel turns and in turn these dictates how fast the wheels turn and consequently how fast the hands turn since the wheels are ultimately attached to these!

Pretty clever stuff!

[sbwhart]

For a pendulum clock it the length of the pendulum, not quite shur what it is for a spring clock i'll have to look that one up.

Stew

[Darren]

Pretty clever stuff!

Certainly is !!

The study needed to make one from scratch must be immense  

[bogstandard]

I have somewhere in my house an old solid silver pocket watch, I think from the 1880's. It has a very nice chain driven fusee movement. Retailed by a jeweller who traded at some time in my home town, so it hasn't travelled far in it's life. By the scratched on markings inside the case, it has been repaired and regulated a few times.

It tells perfect time, even as accurate as the atomic clock, but only twice a day (it does work well though, when wound with the key, but not quite so accurate)

The value in the UK, the scrap value of the case, around 30 to 40 squid. The insides are discarded and the cases melted down. It is better value to have it as a keepsake and talking point rather than selling it.

I must root it out one day and see if it is still telling good time.


Bogs

[raynerd]

For a pendulum clock it the length of the pendulum, not quite shur what it is for a spring clock i'll have to look that one up.

Stew, when fixing a few spring clocks, there is a little lever that moves up and down and contacts the spring at various positions. Effectivelty, it makes the recoil of the spring faster or slower. With the lever contacting to make less spring length, the balance moves faster and vice versa. I don`t know any of the physics behand it but when looking at one for real it does make sense.



Part 2 on the picture shows the lever I was talking about that makes contact with the spring to shorten or lengthen its length.

Chris

[Bernd]

Hi Bernd
Thanks for the extra pics it has given me some ideas. I really like that - how long have you had this clock?

We got that clock at an auction at least 5 years ago. Needs a bit of tender care. It runs but stops often. There are many loose fitting parts that need a bit of tightening up. It's on my to do list way near the bottom.

Bernd