POUVILLON RESTORATION PROJECT - August 2011
Disassembly. Remove complications, Lunar
indicator, planisphere, tellurian-orrery, sun-moonrise dials, equation of
Photo 9 001.
Here we have the planisphere mechanism as well as the drive and the lunar
mechanism. Of interest is that Mr. Pouvillon, it appears, to have silvered
all components in the lunar and planisphere mechanism. The plates and the
gears all appear to be silvered; altogether a dainty piece of engineering.
Photo 9 002 is a close up of the
planisphere. Of interest to note is the #58 punch mark on the lower left
gear projecting from between the plates, also the generally bad corrosion or
tarnish of the silvered components but also rust on the blued screw on the
upper left. The bevel gear projecting beyond the frame is the input drive to
Photo 9 003
gives us close up of the lunar mechanism. The lower arbor on the right hand
side is the in feed. It has a square on the top which apparently is for
setting. This gear is only fixed by means of a taper to the arbor
fit). The next gear is an idler and, of course, the third gear
carries on to the worm drive to the moon arbor shaft. Altogether a simple
and extremely dainty mechanism. The arbor across the upper part of the
photograph incorporating a universal joint is the drive that continues up to
the orrery. Photo 9 004. Here we
have a close up of the lower drive to the lunar dial. Of interest is the
construction of the universal continuing up to the orrery. We see what a
beautiful, little mechanism this is. The outer diameter of the ring
surrounding the universal is only 6.8mm or just over a quarter inch in
diameter. The idler gear on the little post with a screw in the top one can
see that its line is slightly skewed exhibiting some signs of wear, but
otherwise a very nice little unit. This use of a
universal joint on the orrery drive to avoid an obstruction is another
indication that the orrery was added later. More detail on this will be
provided in a later segment.
Photo 9 005.
We have a side view of the planisphere. We
see a reversing gearbox which gives counter rotating direction between the
planisphere disc and the indicator hand. In other words the disc rotates
clockwise once in 24 hours or sidereal time, and the hand rotates in the
opposite direction at exactly the same speed.
Photo 9 006. We have a pin
mounted on the dial of the planisphere. There is an identical pin at the 12
o’clock position, 1800 around the dial. As we can see this pin is
slightly bent and there appears to have been either a thin wire or thread
across the front of this dial acting as an indicator.
Photo 9 007. Here we have another
view of the vertical drive from the clock to the lunar dial as well as the
orrery. As we can see on the right, top we have the bevel gear that is
driven by the strike train and it is reduced in speed immediately to the
lower arbor which goes to the lunar dial.
9 008. Here we have
the universal joint removed from the pivot. It is a screw-clamped joint.
Photo 9 009. We have a
photograph of the orrery which dismounts as a complete unit. The only
projection below the square brass base is the in feed arbor that drives the
whole unit. Projecting out of the front of the leap year dial in the center
towards the base we see another bevel gear which is the drive to the globe.
This drive drives the globe at ‘real time’ speed. In other words it moves
second by second; not intermittently like the rest of the orrery which is
driven from the strike train.
Photo 9 010.
This is the underneath of the base of the orrery where we can see the gear
that accepts the drive from vertical shaft from the lunar train. This drive
proceeds upward into the orrery. Also just above the bridge we see an
extension or a pin that drives the one year arbor that is missing on this
clock. And this arbor carries the cams for the day/night length dials as
well as the equation of time cam. To the left of the picture we see the
drive from the time train that drives the globe. Also of interest is in the
center of the plate we see six screws and the center arbor for the orrery.
It appears three screws act as a height adjustment and their heads do not
touch the center plate completely. But there are three other counter-sunk
screws that pull down a flange against the tips of these three screws giving
us a height adjustment for a bevel gear inside the orrery.
here for a discussion about the tellurian/ orrery assembly.
Photo 9 011. Here we have a
clearer photograph of the three clamp screws,
flag 5. One appears to be
slightly loose and the three jack screws which control the height of a bevel
gear on the other side of this base plate.
Photo 9 012.
We have the lower base
plate at the top of the clock onto which the orrery mounts. It’s interesting
to note that this base plate has cutouts for the various drives but it also
carries the drop-down pillars for the day/night, length of day, length of
night assembly. Photo 9 013. We
have a view from the left hand side of the clock towards the base of the
sunrise/sunset dial. Flag 2 and 6 are pointing to the mounting screws which
hold this assembly. It is becoming apparent at this stage that most of the
complications mount on exiting portions of the clock. In other words, there
are no specially incorporated pads or mounting points for any complication
so far that we’ve seen.
We begin to
see a pattern here of evidence that the complications have been added in an
ad hoc manner.
Photo 9 014. We have a rear view
of the sunrise/sunset dial. A few points to take account of is that the two
sector gears have become disengaged from their length of day and length of
night hands or pinions so they are in the incorrect position but they are
displayed like this to show the way they have been made. Also of interest is
the row of screws around the semicircular brass rim behind the chapter ring
which forms a guide for the sunrise/sunset shutters. The input to this gear
system is via the bevel gear seen on the right, lower portion attached to
the steel bracket which carries this whole unit. Also to note is on the two
upper frames carrying the sector gears towards the outer end just slightly
past the main chapter ring is an empty hole. It appears to match with a
mounting screw hole where the frame attaches to the chapter ring on the
front frame. Perhaps Mr. Pouvillon made these frame simultaneously;
sandwiched together. Photo 9 015
gives us a close up of the sun hand which rotates once in 24 hours. It’s
nice to see the delicacy of the engraving. One does wonder whether there was
anything else mounted in the center of this dial (hand).
Because we have a flat, machined pad, but this is only a query. We can also
see some of the filling has been lost from the engraving in the chapter
ring. But otherwise this assembly has largely been gilded and one sees the
befit of the gilding in the almost complete lack of corrosion.
Photo 9 016.
We have a close up of the sunrise/sunset dial. We can see a very faint
marking outline going from the 24 division up through the end of the ‘L’.
Also of note is that sidereal is clearly
hand engraved while most of the numbers, here we have 24 and 23 appear to be
machine engraved. Photo 9 017.
We have an arbor missing a hand for the length of night dial. Both on the
length of day and length of night dial we have this screw projecting from
the side of the frame just above the blued screw which holds the pillar and
there is nothing to show what it is used for. One suspects that it might
have been a stud for an anti-backlash spring similar to a balance
hairspring. But this is only a supposition as there is no collet on the
actual arbor or other indication that such a method was used on this dial or
the length of day dial.
Photo 9 018.
We have another view of the sunrise/sunset
mechanism with the sector gears engaged with the pinions driving the hands
for the length of day and length of night dials.
Photo 9 019. We have the lever
and the crank gear from the equation of time mechanism. Here we have gilded
components again which show very little sign of corrosion. Starting at the
lower end of the lever we have a weight which helps keep the lever in
contact with the missing kidney cam. About one-third from the bottom we have
a protrusion from the side facing backwards in this photograph, two short
pins projecting out from it which seem to be guide pins to keep the lever
from falling sideways off the equation of time cam. As this lever is raised
and lowered so it partially rotates the gear attached to the blued rod and
this gear, in turns, operates on the differential which gives us the
difference between mean time and solar time and displays it on the ‘mystery
dial’. Photo 9 020 is a bad
photograph of the equation of time differential. We also see the vertical
arbor just behind the dial that was formerly attached to the glass tube that
drove the mystery dial. Also noticeable is that the dial support frame is
only attached with one screw and not completely tightened. Whether this was
done when the mystery dial was removed for transport or exactly why it is
like this is unknown but obviously has to be repaired.
Photo 9 021.
We have another view of the drive to the glass tube to the mystery dial and
also the loose dial support.
Photo 9 022.
We have another overall view of the near naked movement with all the
complications removed. It is interesting to note that we still have not lost
a unity of design due to the complications removed. We’ll see how this idea
progresses as we remove the final upper plate that carried the orrery in the
Photo 9 023.
We have a photo of the bare movement showing
only the time train, pallets of course, and the strike train giving us the
appearance of a fairly basic, standard skeleton clock.
Photo 9 024. We have the rear
view of the main time dial. It’s nice to notice the curling on the back of
the dial. Also interesting are the special countersunk screws which hold
this dial to the main frame of the clock. It is a countersunk screw but has
also been reduced below the countersunk head to give a very flat screw. So
it appears that the screw is countersunk into the front of the dial but it
is actually, I should say, counter-bored but is actually a plain
countersink. Also interesting is the way Mr. Pouvillon has attached the rim
of the dial to the back plate.
Photo 9 025
is a close up of a bezel clamping screw and
also shows off the curlage well. Of interest is that we have the junction of
the prime support and the main support outer frame. We see the last curling
application as a full circle. Photo
9 026. We have side view of the bezel, a close up, showing a worm hole
in the brass. Well, of course, we don’t have worms that eat brass so I
suppose it is actually a casting defect.
Photo 9 027.
We have a close up of the equation of time differential and the frame on
which the differential mounts or pivots. We see the bevel gear going up to
the blue arbor that goes to the glass tube driving the mystery dial. And an
interesting feature on the contrate wheel on the differential gear box is
very nicely recessed and carries the mating bevel gear that drives the
mystery dial, altogether a nice compact, complex little mechanism.
Photo 9 028.
We have the equation of time differential mounted in the pivot on its frame.
We see a few interesting features, numbered screws as well as identification
punches showing their correct location on the contrite wheel. This is a
feature that helps any restorer and makes our life a little easier.
Photo 9 029. A side view of the
equation of time mechanism. Photo 9
030. We have another side view of the equation of time differential and
we can see the two small bevels meshing giving us the drive from the
differential through to the mystery dial.
Photo 9 031.
We have the motion work to the main time dial. We have a copper, or a bronze
anti-rattle washer that goes between the minute and the hour gear. The rod
coming to the top left hand corner of the photograph is the lever tripping
the strike. Also interesting to note is that Mr. Pouvillon has used a
hexagonal nut to retain the lower gear in this picture.
Photo 9 032. We have a close up
the hexagonal retaining nut and washer on the motion work.
Photo 9 033.
We have a view from the front of the clock with the main time dial removed
and we see the major portion of the strike train; the pinwheel that lifts
the strike hammer as well as the propeller-shaper governor fan. We also see
the slot in the base for both the time and strike weight cords. Another
interesting feature seen above the second brass gear from the left hand side
of the strike train is the vertical lever coming down from the motion work
where Mr. Pouvillon has incorporated an ‘S’ bend to give one a simple length
adjustment to get your banking to occur at the correct point.