Now we can readily
understand that the lighter we make the parts _i j k m_, the weaker the
spring _h_ can be. You say, perhaps, if we make it too weak it will be
liable to buckle under the pressure of the escape wheel; this, in turn,
will depend in a great measure on the condition of the spring _h_.
Suppose we have it straight when we put it in position, it will then
have no stress to keep it pressed to the holding, stop or banking screw,
which regulates the lock of the tooth. To obtain this stress we set the
foot _F_ of the detent around to the position indicated by the dotted
lines _r_ and _n_, and we get the proper tension on the detent spring to
effect the lock, or rather of the detent in time to lock the escape
wheel; but the spring _h_, instead of being perfectly straight, is bent
and consequently not in a condition to stand the thrust of the escape
wheel, indicated by the arrows _o p_.
OBTAINING THE BEST CONDITIONS.
Now the true way to obtain the best conditions is to give the spring _h_
a set curvature before we put it in place, and then when the detent is
in the proper position the spring _h_ will have tension enough on it to
bring the jewel _s_ against the stop screw, which regulates the lock,
and still be perfectly straight.
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