The "Floating Balance"
Ah, sacré Franz Hermle. They never did anything like the others. Sometimes I suspect that this was to get around patent laws ( I will write more on this later, as it is one of my pet rants ), but sometimes they had some very bright ideas. Smiths and Bulova used the floating balance too, but I think it was invented by Blech and Hettich* around 1957.
This is not the same movement, but I suspect the escapement is something similar. -
http://www.hermle-clocks.com/user/engl/start.php4 then go to "Movements" (it's php...)
The "Floating balance" resembles a classic regulator, only it's inside out - instead of pivots turning in jewel holes the holes are mounted in a tubular balance staff which turns on a tightly-stretched wire. This allows the balance wheel to "float", as the name would suggest, and replacement of the wire is much easier than planting new pivots, although still not for the faint of heart (guitar string.**...). A balance wheel in a table clock has many advantages over a pendulum - the clock is transportable, does not need to run level, beats faster so is liable to be more accurate.
However a balance wheel escapement runs best if the wheel axis is vertical - any static imbalance of the wheel will not affect the timekeeping as the spring winds down (and the amplitude diminishes), and there is less friction as the wheel rests on one end pivot, practically a point-contact since said pivot should be nicely rounded, rather than on two line-contacts. The main obstacle to having a vertical-axis balance lies in the fact that the train-wheels are horizontal, and the motive force must be turned through 90º. The contrate gear that achieves this has always and forever been a source of trouble - in classic carriage "5-glaces" clocks the tooth penetration of the contrate wheel into the escape wheel pinion is adjustable, and thus prone to be badly adjusted...
Hermle cleverly gets round this by using the "anchor" of the escapement to turn the corner. The rather crude looking "pin-pallet" escapement is another clever, although much deprecated idea - the impulse faces are on the escape wheel, and the pins are easily replaced (more guitar strings...).
The double-helix (it's life, Jim, but not as we know it) hairspring is to prevent vertical movement of the wheel, one half contracting as the other expands.
Cleaning? Well, get rid of all that oil, for a start ! At least the thing won't have rusted. No alcohol ! I am reluctant to publish "keep out of the reach of children" formulæ on a public site, but if anyone is interested, write to me - I have some great Witches Brews in my cauldron....
More about lubrication in another post - watch this space...
* http://www.clock-museum.co.uk/c191.htm
**No shit! And to get the wire taut enough I mounted the string on an old guitar and "tuned it up" before soldering it in place...
This is not the same movement, but I suspect the escapement is something similar. -
http://www.hermle-clocks.com/user/engl/start.php4 then go to "Movements" (it's php...)
The "Floating balance" resembles a classic regulator, only it's inside out - instead of pivots turning in jewel holes the holes are mounted in a tubular balance staff which turns on a tightly-stretched wire. This allows the balance wheel to "float", as the name would suggest, and replacement of the wire is much easier than planting new pivots, although still not for the faint of heart (guitar string.**...). A balance wheel in a table clock has many advantages over a pendulum - the clock is transportable, does not need to run level, beats faster so is liable to be more accurate.
However a balance wheel escapement runs best if the wheel axis is vertical - any static imbalance of the wheel will not affect the timekeeping as the spring winds down (and the amplitude diminishes), and there is less friction as the wheel rests on one end pivot, practically a point-contact since said pivot should be nicely rounded, rather than on two line-contacts. The main obstacle to having a vertical-axis balance lies in the fact that the train-wheels are horizontal, and the motive force must be turned through 90º. The contrate gear that achieves this has always and forever been a source of trouble - in classic carriage "5-glaces" clocks the tooth penetration of the contrate wheel into the escape wheel pinion is adjustable, and thus prone to be badly adjusted...
Hermle cleverly gets round this by using the "anchor" of the escapement to turn the corner. The rather crude looking "pin-pallet" escapement is another clever, although much deprecated idea - the impulse faces are on the escape wheel, and the pins are easily replaced (more guitar strings...).
The double-helix (it's life, Jim, but not as we know it) hairspring is to prevent vertical movement of the wheel, one half contracting as the other expands.
Cleaning? Well, get rid of all that oil, for a start ! At least the thing won't have rusted. No alcohol ! I am reluctant to publish "keep out of the reach of children" formulæ on a public site, but if anyone is interested, write to me - I have some great Witches Brews in my cauldron....
More about lubrication in another post - watch this space...
* http://www.clock-museum.co.uk/c191.htm
**No shit! And to get the wire taut enough I mounted the string on an old guitar and "tuned it up" before soldering it in place...
posted by Simeon Lapinbleu at 20:16
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