that they are needlessly elaborate, and confer
no practical advantage over the simpler form of
regulator as fitted to a cheap alarm clock. Only
i f it is desired to construct a faithful replica of
the original clock is it considered worth while to
follow these details exactly. It will be seen that
the regulator quadrant is equipped with a
Fig.
16.
Ratchet lever
toothed segment, engaging a pinion carried in a
plate attached to the rear motion-plate of the
clock, and fitted with a star wheel on the outside,
by means of which it is operated. The quadrant
plate has a 1/4 in. pivot hole which fits over the
spigot of the rear balance pivot housing, and is
retained in place by fitting a washer over it and
lightly burring over or expanding the end of the
spigot, so that it moves with some friction. A
curved slot is cut in the lower end of the quadrant,
which is located by springing it into a slot at the
root of the boss which clamps the end of the
hairspring, and this boss also limits the motion
of the quadrant, preventing the sector from
moving far enough to get out of mesh with the
pinion.
MARCH 31, 1949
wheel may be entirely omitted, also the toothed
sector of the quadrant, but the latter should then
have a second arm extending upwards for opera-
ting purposes. A rating plate may be fixed to
the pivot housing to indicate the position of the
arm, and show the direction in which it must be
moved to produce a faster or slower rate.
Ratchet Lever
As already mentioned, this component was
entirely absent when the clock was submitted
for restoration, and has been produced from first
principles, so there is no guarantee that it is
identical with the one originally fitted. The
form in which it is made is somewhat elaborate,
involving the use of three separate parts held
together by 14-B.A. screws, and a simpler con-
struction, with the parts fabricated by sweating
or riveting would serve just as well, but it should
be noted that the construction was experimental
and tentative, and several alterations were called
for before it produced the desired result, so
that a method of construction which conferred
some measure of mutability was clearly indicated.
(Fig.
16.)
The top end of the lever is extended at right
angles to its main length and carries a large
diameter disc roller, which is reduced to a narrow
rounded edge and polished to reduce friction
when in contact with the eccentric on the balance
staff. This may be turned from the solid, as the
more orthodox horological method of making
it separate, fixing it to a brass collet, and mounting
the latter on an arbor, confers no practical
advantage, and entails much more work. Mild-
steel, case-hardened on the working surfaces
is a suitable material and easier to machine than
a carbon steel which could be hardened and
tempered. The pivots should be highly polished
and made a little larger than the holes in the
lever, which are broached to a working fit ;
The arm extending horizontally from the
quadrant is bent U-shaped at the end, and notches
are cut across the span, into which brass curb
pins approximately 1/32 in. diameter are sweated.
Fig. 17. Roller
Under working conditions, these allow a little
play for the hairspring, which passes between
them, and should touch each of them in turn
as it expands and contracts with oscillation of the
this applies also to the other pivot holes for the
balance wheel. By moving the quadrant towards
feed paw1 and the lever itself. (Fig.
17.)
the anchorage of the spring, its effective free
Case-hardened mild-steel may be used also
length is increased and the clock is slowed down
;
for the pawl, similarly turned from the solid,
movement in the other direction has the reverse
complete with its pivots, and filed to the shape
effect and increases the working rate.
shown. Before hardening, it should be tried out
If it is decided to simplify the regulator, it is
in position to check up on the shape of the point,
which should fit the ratchet wheel teeth when
suggested that the pinion, pivot plate and star at the end of its working stroke. The lever pivot
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