Nicholas Bodley
2011-09-25 18:49:53 UTC
Dear a.h people,
Among other subjects, I'm also interested in calculators, especially
mechanical. A subscriber to a mailing list for enthusiasts and collectors
Asked for help and information about a Calculagraph. That's a trade name
for a small number of different models of printing clocks (with a
conventional dial). They print event start time onto a card when a lever
is operated, as well as elapsed time when another lever is operated.
Because (like old time clocks), these overlap into horology, I thought
they might be of interest.
This page has a good lot of information, including patent numbers:
<http://www.prc68.com/I/Calculagraph.shtml>
I'm pondering whether there would be a differential in the movement;
probably not, I'm thinking. Instead, the "dials" for the elapsed-time
print section would probably rotate, as well as the pointers.
===
Regarding timekeeping, sources I trust say that the atomic clocks aboard
GPS satellites are periodically corrected to about a picosecond.
Considering that light travels on the order of a nanosecond per foot,
that's very impressive.
===
As a youngster, around 12 or so, my father bought a truckload of semi-
smashed IBM mechanisms that was destined for the junkyard. When the load
was put into our living room, my mother was Not Happy.
Included were two or more pendulum clocks (dead-beat escapement) for
employee time clocks. They had hefty dual mainsprings and a set of miter
gears that provided a shaft drive down to the time/date print-wheel
mechanism. (Also had one or more of those.) I no longer recall the rate
of that shaft, but it was probably one rev/hour. That, however, would
mean continuous advance of the minutes print wheel (00-59), and afaik,
minutes were printed properly aligned.
Carries (think calculators; minutes to hours, hours to day of week, etc.)
were by snail cams with one "dropoff" that raised weights. When the
weights fell, the force advanced the next print wheel. I never did try to
outfit the movement with proper-length pendulums, but the movements were
undamaged, and simply hanging a mass onto the pendulum "coupling wire" at
the back set them running, although much faster than intended.
When I disassembled a small rectangular lady's watch (incl. removing the
balance and hairspring), and reassembled it so it ran, I figured I'd
"earned my stripes".
=====
On a personal note, sorry to say I've had a spell of reclusiveness
related to mild (moderate?) depression; still physically healthy, however.
Current news about a neutrino beam going a wee bit faster than light
recalls the Michelson-Morley experiment.
Here's hoping that you're all well!
Best regards,
Among other subjects, I'm also interested in calculators, especially
mechanical. A subscriber to a mailing list for enthusiasts and collectors
Asked for help and information about a Calculagraph. That's a trade name
for a small number of different models of printing clocks (with a
conventional dial). They print event start time onto a card when a lever
is operated, as well as elapsed time when another lever is operated.
Because (like old time clocks), these overlap into horology, I thought
they might be of interest.
This page has a good lot of information, including patent numbers:
<http://www.prc68.com/I/Calculagraph.shtml>
I'm pondering whether there would be a differential in the movement;
probably not, I'm thinking. Instead, the "dials" for the elapsed-time
print section would probably rotate, as well as the pointers.
===
Regarding timekeeping, sources I trust say that the atomic clocks aboard
GPS satellites are periodically corrected to about a picosecond.
Considering that light travels on the order of a nanosecond per foot,
that's very impressive.
===
As a youngster, around 12 or so, my father bought a truckload of semi-
smashed IBM mechanisms that was destined for the junkyard. When the load
was put into our living room, my mother was Not Happy.
Included were two or more pendulum clocks (dead-beat escapement) for
employee time clocks. They had hefty dual mainsprings and a set of miter
gears that provided a shaft drive down to the time/date print-wheel
mechanism. (Also had one or more of those.) I no longer recall the rate
of that shaft, but it was probably one rev/hour. That, however, would
mean continuous advance of the minutes print wheel (00-59), and afaik,
minutes were printed properly aligned.
Carries (think calculators; minutes to hours, hours to day of week, etc.)
were by snail cams with one "dropoff" that raised weights. When the
weights fell, the force advanced the next print wheel. I never did try to
outfit the movement with proper-length pendulums, but the movements were
undamaged, and simply hanging a mass onto the pendulum "coupling wire" at
the back set them running, although much faster than intended.
When I disassembled a small rectangular lady's watch (incl. removing the
balance and hairspring), and reassembled it so it ran, I figured I'd
"earned my stripes".
=====
On a personal note, sorry to say I've had a spell of reclusiveness
related to mild (moderate?) depression; still physically healthy, however.
Current news about a neutrino beam going a wee bit faster than light
recalls the Michelson-Morley experiment.
Here's hoping that you're all well!
Best regards,
--
Nicholas Bodley __-/^\-__ Waltham, Mass.
Nicholas Bodley __-/^\-__ Waltham, Mass.