The stand alone weight for tower clock

[dk0Participant @dk0]

I designed and built an automatic weight for a tower clock.
The operating principle is called “Monkey up the rope.” Essentially, the weight contains a gear motor and lead plates. The motor winds itself up the chain when it has descended to a certain level. This system has the advantage of keeping the pendulum constantly loaded. Another advantage is that the application not requires machining or mechanical modifications to the antique clock. I’ve made a dozen of them, and they’ve been working perfectly for over five years. The overall weight is adjustable using additional plates and varies from 12 to 25 kg.

[bernard towersParticipant @bernardtowers37738]

That would make a good article for the magazine, any more info?

[Nigel Graham 2Participant @nigelgraham2]

I agree!

It’s an interesting solution to an old problem and it would good to read about in ME&W.

[dk0Participant @dk0]

No problem providing information about this product.This project was born from the need to automate antique clocks without compromising or altering their originality, as required by art heritage laws.
The application only requires the diameter of the rope barrel to provide the corret diameter of the roller chain crown.

The kit consists of the weight assembly + 5 meters of roller chain + a crown that encircles the barrel + a small 220/12-volt transformer.

[BazyleParticipant @bazyle]

An interesting concept and food for thought. I think I would have a short chain and just attach it to the end of the rope to avoid having to get ‘into the works’.

[Bazyle]

On Bazyle Said:

An interesting concept and food for thought. I think I would have a short chain and just attach it to the end of the rope to avoid having to get ‘into the works’.

I don’t understand how it could work…. the weight just attach it to the end of the rope .

[duncan webster 1Participant @duncanwebster1]

Love it, almost makes me want to make a conventional clock so I can have the weight shimmying up every so often

[John HaineParticipant @johnhaine32865]

Another approach would be to drive the “monkey” with a stepper motor synched to the clock pendulum with some electronic “gearing” so it climbs up as fast as the chain rolls down.  Would need much less height.  Need quite a lot of mechanical gearing between the stepper and sprocket but steppers with gearboxes are quite cheap.

[duncan webster 1Participant @duncanwebster1]

If you go down that route you could drive the escape wheel direct from the stepper via a torsion spring, sort of permanent remontoire.

[Nigel Graham 2Participant @nigelgraham2]

That would be a significant change to the way the clock works, though. Fine for a new project, and no doubt interesting to build, but not when maintaining the original.

The only “modification” dk0 has made, is to fit a sprocket to the rope-drum – readily reverted to full weight and cord power.

Also, would using a torsion-spring remontoire place a brief interruption to the escape-wheel drive each time it acts?

 

[Nigel Graham 2]

On Nigel Graham 2 Said:

……

Also, would using a torsion-spring remontoire place a brief interruption to the escape-wheel drive each time it acts?

 

Don’t think so, escape wheel on one end of torsion spring, stepper on the other. Escape wheel is driven continuously by the wind up in the spring.

[John HaineParticipant @johnhaine32865]

The scape wheel of a Harrison clock is driven by a much coarser stepping remontoire than a stepper motor. I first suggested this approach in an HJ article a few years ago = given that “Clock B” uses a lever lifting a weight and pivoted off the minute arbor with a worm motor drive controlled by a mercury level switch, the stepper remontoire would probably work better and take almost all the torque load off the train.

[dk0Participant @dk0]

Remaining on the subject of restoring antique tower clocks, another aspect requiring attention is synchronization with the exact time.
The device designed is an electromechanical actuator controlled by a small PLC. Every 24 hours, the synchronizer activates a V-fork that indexes a pin on the minute wheel, correcting any errors of the pendulum.

[dk0Participant @dk0]

With these two simple devices, automatic weight winding and the exact time synchronizer, any old tower clock can be returned to its glorious function.

[Marcus BowmanParticipant @marcusbowman28936]

That’s an interesting device.

Does that forked device cope with both slowing the minute wheel when the clock is running fast and advancing it when the clock is running slow?

Are the limits on adjustment set by the aperture of the fork?

I assume this requires a pin to be added to the minute wheel?

Does the device have its own GPS-locked internal clock? So does it require a GPS antenna?

[Michael GilliganParticipant @michaelgilligan61133]

Excellent stuff … keep-up the great work !

Could you show us the locations of these ‘family’ clocks please?

MichaelG.

[John HaineParticipant @johnhaine32865]

If it only corrects the minutes then GPS is hardly relevant.

[Marcus Bowman]

On Marcus Bowman Said:

That’s an interesting device.

Does that forked device cope with both slowing the minute wheel when the clock is running fast and advancing it when the clock is running slow?

Are the limits on adjustment set by the aperture of the fork?

I assume this requires a pin to be added to the minute wheel?

Does the device have its own GPS-locked internal clock? So does it require a GPS antenna?

The forked device can correct the error by +/- 1.5 minutes.

Yes, the limits are determined by the fork width.

A pin is mounted to the minute wheel.

The PLC has its own quartz with high accuracy.

 

[BazyleParticipant @bazyle]

The synchroniser is interesting. Tower clock? Ours takes quite a lot of force to correct but not sure if that is the weight of the hands and gearing or just the friction to lock the arbor and wheel is set high.

[Michael GilliganParticipant @michaelgilligan61133]

I find it ‘philosophically’ rather pleasing that these magnificent old Tower/Turret Clocks have entered a new chapter in their history.

Once they were cutting-edge ‘Keepers of Time’ and they have gently morphed into well-earned  retirement, as ‘Displayers of Time’

MichaelG.

[Bazyle]

On Bazyle Said:

The synchroniser is interesting. Tower clock? Ours takes quite a lot of force to correct but not sure if that is the weight of the hands and gearing or just the friction to lock the arbor and wheel is set high.

The shaft that transmits the movement to the hands doesn’t require much force to turn because it’s highly geared, and the weight of the hands doesn’t affect it either, as they should be balanced, so I think something’s out of place causing this stiffness.

P.S. Please note that to correct the position of the hands, you need to release a minute indexing device.

[Michael Gilligan]

On Michael Gilligan Said:

Excellent stuff … keep-up the great work !

Could you show us the locations of these ‘family’ clocks please?

MichaelG.

My family produced about 100 tower clocks between 1850 and 1940. At that time, these clocks were located in our region of Emilia Romagna (Bologna).
Of these clocks, 23 are still in working order, they are remotely controlled and I regularly maintain and service them.

[Michael GilliganParticipant @michaelgilligan61133]

Thank You

MichaelG.

[Robert Atkinson 2Participant @robertatkinson2]

How does the monkey “know” when to start and stop climbing? Are there limit switches attached to fixed points? Perhaps on a seperate rope.

[Robert Atkinson 2]

On Robert Atkinson 2 Said:

How does the monkey “know” when to start and stop climbing? Are there limit switches attached to fixed points? Perhaps on a seperate rope.

Stop climbing with a microswitch mounted on the weight.
Start climbing microswitch mounted on the weight and activated by the lower radius of the chain or alternatively, by a timer with programmed descent time.

[Author]

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