Automatic watches
Discussion
elster said:
How much movement do they need to be kept running?
Movement dependent, but most 'typical' automatics will last around 40-60hrs once fully wound. To fully wind you'd need a relatively active day. elster said:
Are different internals vastly different?
Yes. Different layouts of dials, date almost never-ending.elster said:
If so, which ones work most efficiently?
Pass on that one I'm afraid, but things like Omega's co-axial movement would be beneficial for efficiency I'd have thought.elster said:
Also what makes them so different?
Date function, day-date, day-date-month, perpetual calendar chronograph, moonphase, GMT function etc. as complications. Then in-house from bought in movements. You'll find more variation in types from around the 30's-60's, when mechanical watches were in fierce competition with each other and the automatic was a relatively new idea. I don't have my complications book handy, but it features somethign like twenty different types. If you wanted to start a collection, trying to have one of each winding system would keep you pretty busy & give you some interesting stuff, it's a whole field of its own which, sadly, I haven't studied properly yet.
These days the most popular types are variations of either rocker/cam/lever winding systems (as used in many Japanese designs, though I'm sure the swiss used them, too. The Smiths Watch company used a similar type), in which the direction of the rotor causes a "claw" to either push or pull a winding wheel around, thus winding the watch. Something like this, where the big wheel on the left has a cam underneath it, causing the claw to pull or push the fine-toothed wheel around:
The other type, as seen in many Swiss designs, uses some wheels, one of which is reverser wheel with a ratchet, to ensure that the winding wheel is wound in the same direction, regardless of the direction the rotor is travelling. Other similar types wind in only one way, like this one, where the rotor engages with the left most wheel, winding the rightmost wheel in one direction, and disengaging or slipping in the other:
There's a good article on the bidirectional reverser wheel automatic system here:
http://www.timezone.com/library/horologium/horolog...
In terms of pure winding efficiency, I don't honestly know the most efficient system. I have even heard that unidirectional systems can be more efficient than bidirection, which initially sounds counter-intuitive. As I said above, I don't understand the subject deeply enough to be able to give a conclusive answer. Practically, though, much depends on the size/inertia of the rotor and design of the base movement itself. Daily wear is usually enough for most watches to keep a full wind.
My personal faves are the old bumper types:
and microrotors:
These days the most popular types are variations of either rocker/cam/lever winding systems (as used in many Japanese designs, though I'm sure the swiss used them, too. The Smiths Watch company used a similar type), in which the direction of the rotor causes a "claw" to either push or pull a winding wheel around, thus winding the watch. Something like this, where the big wheel on the left has a cam underneath it, causing the claw to pull or push the fine-toothed wheel around:
The other type, as seen in many Swiss designs, uses some wheels, one of which is reverser wheel with a ratchet, to ensure that the winding wheel is wound in the same direction, regardless of the direction the rotor is travelling. Other similar types wind in only one way, like this one, where the rotor engages with the left most wheel, winding the rightmost wheel in one direction, and disengaging or slipping in the other:
There's a good article on the bidirectional reverser wheel automatic system here:
http://www.timezone.com/library/horologium/horolog...
In terms of pure winding efficiency, I don't honestly know the most efficient system. I have even heard that unidirectional systems can be more efficient than bidirection, which initially sounds counter-intuitive. As I said above, I don't understand the subject deeply enough to be able to give a conclusive answer. Practically, though, much depends on the size/inertia of the rotor and design of the base movement itself. Daily wear is usually enough for most watches to keep a full wind.
My personal faves are the old bumper types:
and microrotors:
Edited by glazbagun on Tuesday 13th April 19:03
Edited by glazbagun on Tuesday 13th April 21:39
Gassing Station | Watches | Top of Page | What's New | My Stuff