The advantages claimed for the club-tooth escapement are many; among
them may be cited (_a_) the fact that it utilizes a greater arc of
impulse of the escape wheel; (_b_) the impulse being divided between the
tooth and the pallet, permits greater power to be utilized at the close
of the impulse. This feature we have already explained. It is no doubt
true that it is more difficult to match a set of pallets with an escape
wheel of the club-tooth order than with a ratchet tooth; still the
writer thinks that this objection is of but little consequence where a
workman knows exactly what to do and how to do it; in other words, is
sure he is right, and can then go ahead intelligently.
It is claimed by some that all American escape wheels of a given grade
are exact duplicates; but, as we have previously stated, this is not
exactly the case, as they vary a trifle. So do the pallet jewels vary a
little in thickness and in the angles. Suppose we put in a new escape
wheel and find we have on the entrance pallet too much drop, that is,
the tooth which engaged this pallet made a decided movement forward
before the tooth which engaged the exit pallet encountered the locking
face of said pallet.
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