French Clocks

[doc_fields]

Are French clock verges that sensitive to being knocked out of beat? I have had several I have worked on, only to be called back later after the customer has been gone a bit and re-starts their clock pendulum, and have it go out of beat. I do not like the idea of using lok-tite to set it, but there seems no other way sometimes. What am I missing here? I would prefer answers from the more experienced here of those who have worked on these quite often. Thanks........doc

 

[David Robertson]

some are self adjusting. Is this one?

 

[doc_fields]

Not that I know, David, except for the fact that they do move too easily for my liking. And if they're self-adjusting, they knock themselves easily out of beat, like some of the grandfathers. How do I know if it is truly meant to be self-adjusting? One has the crutch thread onto the verge shaft, and as it gets further on, it opens the threaded jaws on the crutch, losing some of it's gripping power. This particular one is a bugger to get into beat, very narrow margin for error, then it runs great. I did use some lok-tite on the threaded portion, but after the customer was gone for ten days, she came back, re-started the pendulum, carefully, I might add, and soon was out of beat again. I like French clocks, but not their verges!.........doc

 

[Joseph Bautsch]

Doc - I've worked on French clocks for many years and yes most have the same problem with staying in beat. The anchor (verge) on most of them are friction fitted on their arbor. A friction fit of this type is movable. That was done to make it easier to set the beat without having to bend the crutch. Over time and repeated reseting of the beat the wear on the friction fit causes it to loosen up. That makes the beat difficult to hold. Some of the works I've worked on had the joint between the arbor and anchor soldered by prior repairmen. Not a good solution. The solution I use is to put a small touch of epoxy glue at the joint to hold the anchor in beat. The epoxy can be removed and the escapement worked on or the beat reset if needed without damaging arbor or the anchor. Lok-tite won't work unless you can get it inside the anchor/arbor joint. I don't think that's practical.

 

[harold bain]

Another related problem with French clocks is if the screws that hold the movement are not tight enough, the movement itself will move when winding the clock, putting it out of beat.

 

[Chris]

I've got one that is loose on a silk thread movement, but a gentle push adds friction and it can be set. The problem is that many like these on the mantle. Well, mantles are not deep enough to allow you to open the door and install the pendulum. Therefore, they hang the pendulum then move the clock. If they're not careful, they can easily set it offbeat.

I had a newer one (1880's) that was an open escapement that was difficult to set. Turns out, it's a self-regulating one that works as it should. A gentle overswing and it takes care of itself.

I'm more in favor of trying for a tighter fit (avoiding rubbing on the movement plate) and not putting any type of adhesive, solder, etc. on it. If it's deemed necessary, use anything sparingly.

Harold brings up another point. Make sure it's secure in the case; if the movement slides in the case, you'll get a call.

 

[Joseph Bautsch]

Doc - My error. The problem as you state is in the threaded crutch collar found in most French clocks. It's not the anchor arbor joint as I had indicated. The threaded crutch collar on the escapement arbor is a friction fit. Some say it's a self adjusting device for the beat. It may be, I can't say one way or the other. My thought has always been that it's to make the beat easier to set. Whatever the reason the French did it that way the same problem remains. After the beat has been set and reset over many years the joint gets loose and the beat is difficult to hold. As I said I've seen many of these loose collars soldered by prior repairmen. The best solution I've come up with is to put a touch of epoxy glue spanning the joint between the collar and the arbor. (Not inside the joint on the threads.) This will hold the collar firm enough that it will hold the beat. The epoxy can also can be easily removed for work latter on or resetting the beat.

 

[tymfxr]

Most French mantel clocks are placed on a shelf or MANTLE. So the customer picks it up or reaches around the back, opens the door, and pushes the pendulum too hard. Not good for keeping it in beat. Or they will tilt the clock too vigorously to start the pendulum swinging. Either way it may cause the crutch to slip or bend.
Mike C.
aka
clock whisperer

 

[doc_fields]

Thanks guys for all of your input. This clock that I mentioned about the crutch threading onto the arbor is a cast brass figure clock sitting on a bureau in the customer's home. the pendulum is easily accessible without doing any gymnastics to start it. I did put lok-tite, medium strength on the threaded portion of the verge shaft, and threaded the crutch onto that, knowing it would only set where air could not reach it, since it's anaerobic. It has never, even with careful levelling, ever put itself into beat after starting the pendulum, but instead will quit or knock itself out of beat. I know French clocks are famous for their glass hard pinions and hard shafts, so I never tried the peening method, or stippling one part or the other so it tightens up the fit.
Once again, thanks for the replies...............doc

 

[John C. Losch]

6/15/07

It is a big mistake to tighten the joint between the verge and the pallet arbor of French clocks. Most of the time the trouble with getting these clocks in beat is that the friction is too great at the joint. The whole idea of this arrangement is that the pendulum, when the clock is started, can be made to swing well in excess of the normal swing that results when the motion of the pendulum achieves equilibrium with the force delivered by the escape wheel.

When the pendulum swings widely the pallet faces bottom in the teeth of the escape wheel until the pendulum has settled to a shorter arc. As this occurs the pallets become centered in relation to the escape wheel so that the clock becomes automatically in beat. Sometimes it requires more than one try for this to happen, but usually it will work with little or no difficulty.

This system of finding beat demands that the friction between verge assembly and pallet arbor have only enough friction to assure that impulse is delivered to the pendulum. When there is too much friction the clock will not put itself in beat. Worse, it is possible for the pallets to bend a delicate escape wheel, or for jeweled Brocot pallets to get broken. The verge should slip when it is pushed with a feather!

A lot of though went into this design, and it is folly to try to outsmart the original builders of these clocks. Jcl

 

[doc_fields]

John,
Please PM me....................doc

 

[Sooth]

Can I just ask a very simple question: Why does the clock ever need to be restarted in the first place? French clocks are usually 1 week clocks, but they are so incredibly well made that they usually last up to 14 days.

Your client is likely not winding the clock properly, or often enough. I have 2 French clocks, and I rarely ever need to restart them (usually only when I'm away for over a week).

As for the anchor being friction fit, both of mine are not. They appear to be (from memory) a solid piece of metal, slipped onto a square arbor. The only way to make an adjustment is to bend the crutch, or turn the entire mechanism within the case. Again, I don't remember either one being at all loose, or adjustable (they MIGHT be, but not that I can remember). Both are S. Marti clocks.

Apparently, however, this is not true on other French clocks, as mentioned several times above.

 

[Mike Phelan]

Sooth
All the French crutches of this sort I have seen are split and run on a threaded pallet staff (US=verge).
Occasionally the brass boss is split, which loosens the crutch.
If the split is closed up it should work fine without making it solid, which could damage the EW or break a ruby pallet if it is a Brocot escapement.

 

[doc_fields]

Sooth;
The customer was gone for ten days overseas, that's why she needed to re-start the clock.
Tymfxr;
This clock's pendulum can be started by reaching underneath much like an American 8 day black mantle, and gently starting the swing. No need to open the rear door. Besides, the strike bell is in the way of reaching the pendulum.
Thanks all.....................doc

 

[Sooth]

Doc, thanks for clarifying.

Mike, I'll have to have another look at the crutch assemblies in both my clocks. From what I remember, though, the main arbor is turned on the back end, and it's square on the other half, where the anchor is slipped on (the square). The actual crutch piece may be friction fit on the round section, but I don't remember being able to move it at all. As I recall, I had to hold the anchor firmly, then force the crutch to bend it to be able to set the clock in beat at a 90 degree angle, before I put it back in the case.

I don't remember seeing anything that was threaded.

I'm actually quite curious now, and I just might go an dismantle my fairly simple slate clock. I can take the whole verge/anchor out, and photograph it.

 

[Sooth]

Here, as you can see, this one is one piece, and very much unadjustable. The two French clocks that I have both have the exact same setup.



I'd be very curious to see a photo of the other type, which you can adjust. I don't quite understand this whole "split" and "threaded" business.

 

[Joseph Bautsch]

Here, as you can see, this one is one piece, and very much unadjustable. The two French clocks that I have both have the exact same setup.

I'd be very curious to see a photo of the other type, which you can adjust. I don't quite understand this whole "split" and "threaded" business.

Sooth - It's the brass crutch collar that gets loose. It's usually threaded on to the steel arbor with a tight fit. It is movable, left or right, to set the beat. Over the years the fit between the collar and the steel arbor loosens up consequently making it difficult to keep in beat. Allegedly it was done that way as a self adjustment for the beat. The theory was that more pressure would be applied to the out of beat pallet as the pendulum swung in that direction there by causing the crutch to move on the arbor in the opposite direction. It would do that until the applied pressure on the pallets were equal thereby keeping the clock in beat. In my experience I've never seen the theory work out that way.

 

[clocker2]

Can I just ask a very simple question: Why does the clock ever need to be restarted in the first place? French clocks are usually 1 week clocks, but they are so incredibly well made that they usually last up to 14 days.

Your client is likely not winding the clock properly, or often enough. I have 2 French clocks, and I rarely ever need to restart them (usually only when I'm away for over a week).

Its not just stopping that throws it out of beat. If the customer turns the minute hand backward, the escape wheel can turn backward and catch on the verge, causing it to go out of beat.

Jeff Major

 

[Mike Phelan]

Mike, I'll have to have another look at the crutch assemblies in both my clocks. From what I remember, though, the main arbor is turned on the back end, and it's square on the other half, where the anchor is slipped on (the square). The actual crutch piece may be friction fit on the round section, but I don't remember being able to move it at all. As I recall, I had to hold the anchor firmly, then force the crutch to bend it to be able to set the clock in beat at a 90 degree angle, before I put it back in the case.

I don't remember seeing anything that was threaded.

I'm actually quite curious now, and I just might go an dismantle my fairly simple slate clock. I can take the whole verge/anchor out, and photograph it.

Sooth
That one is definitely not threaded - most of them are, though.

I think that all the wheel collets are soft-soldered on to the arbors, so it is possible that the crutch collet is as well, if there is no visible slit.

 

[Kevin W.]

Sure would be nice if people would use pictures from their computer and not some outside source. Pictures get lost and the thread is not worth as much to others later that find these threads.

 

[D.th.munroe]

Which do you need a pic of Kevin? I have boxes of these.
I've found the biggest reason for them going out of beat is the movement turning while winding.
Also in my experience most brocot ones seem to be adjustable and threaded on the arbour and the standard anchors are not.
Dan

 

[Kevin W.]

I have a crystal regulator which has a lose verge, dificult to say the least to put in beat, and for it to keep running. Just wondering how to repair this.

 

[D.th.munroe]

Do you have a picture?
For adjustable ones, sometimes I take the crutch off and wrap a piece of paper or something around the collet, to protect it, if its polished like in a crystal regulator, and put a rod or wire a bit smaller than the arbor in it, so I don't crush it accidentally and carfully squeeze it tighter in a lathe or drill chuck.

If it's non adjustable that could work too.
Some people frown on it, but you could just use loctite or something on those.