An unusual clock

[D.M. Procida]

I bought a kitchen clock in a second-hand shop. I think it must be German, from the around 1960.

Photo:

It's not a good picture, sorry. The clock is ceramic, and is very pretty.

The mechanism is very unusual. It's driven by clockwork, and but powered by a battery.

There's a solenoid, which every minute or so taps a brass disk, spinning it round 120 degrees or so and thus charging up the spring that's attached to it. That spring powers the clockwork mechanism, and as it runs down the disk rotates back to its original position, once again triggering the solenoid that sends it round once more.

I've never seen anything quite like it.

The clock is marked "ELMA Elamatic".

Daniele

[Huge]

Not that unusual in clocks of that age. Several of those in my MILs house had similar mechanisms.

[Graham.]

On 9 Dec 2017 16:16:43 GMT, Huge coalesced the vapors of human experience into a viable and meaningful comprehension...

Quite. The first clock I encountered that worked on this principle was in the dashboard of my grandfathers Hillman Minx.

[Bob Eager]

I've always liked the Congreve clocks, although they are remarkably inaccurate!

[DJC]

I remember (1960s) one with a similar mechanism, mechanical time keeping but electric winding.

[Graham.]

On 9 Dec 2017 18:30:05 GMT, Bob Eager coalesced the vapors of human experience into a viable and meaningful comprehension...

I like digital clocks. Here is a video I shot of my favourite one ;-)

[Brian Gaff]

I have a feeling that that make made novelties. When I worked for a TV company, one of the blokes showed me what was called an atmospheric clock. It bore the same name as yours but the battery in this case powered a tiny heater in a cylinder with some kind of valve arrangement. The piston drove a kind of escapement which kept the clock wound up. What I never did figure out was that how it knew it was unwound enough to allow the battery. a U11 to start the piston again. I suppose there must have been some little microswitch somewhere as the spring unwound. The question is, why go to all that bother in the first place? Brian

[Harry Bloomfield]

Brian Gaff submitted this idea :

[Rob Morley]

And I suppose this is an early MIDI implementation.

:-)