Watch and Clock Escapements - A Complete Study in Theory and Practice of the Lever, Cylinder and Chronometer Escapements, Together with a Brief Account of the Origin and Evolution of the Escapement in Horology by Anonymous
page 17 of 243 (06%)
page 17 of 243 (06%)
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position on such matters as Mr. Grossman, because a mistake is a
mistake, no matter who makes it. We will say no more of this error at present, but will farther on show drawings of Mr. Grossman's faulty method, and also the correct method of drawing such a pallet. To delineate the locking face of our pallet, from the point formed by the intersection of the lines _e g b b'_, Fig. 9, as a center, we draw the line _j_ at an angle of twelve degrees to _b b''_. In doing this we employ the same method of establishing the angle as we made use of in drawing the lines _e g_ and _e h_, Fig. 10. The line _j_ establishes the locking face of the pallet _B_. Setting the locking face of the pallet at twelve degrees has been found in practice to give a safe "draw" to the pallet and keep the lever secure against the bank. It will be remembered the face of the escape-wheel tooth was drawn at twenty-four degrees to a radial line of the escape wheel, which, in this instance, is the line _b b'_, Fig. 9. It will now be seen that the angle of the pallet just halves this angle, and consequently the tooth _A_ only rests with its point on the locking face of the pallet. We do not show the outlines of the pallet _B_, because we have not so far pointed out the correct method of delineating it. METHODS OF MAKING GOOD DRAWING INSTRUMENTS. Perhaps we cannot do our readers a greater favor than to digress from the study of the detached lever escapement long enough to say a few words about drawing instruments and tablets or surfaces on which to delineate, with due precision, mechanical designs or drawings. Ordinary drawing instruments, even of the higher grades, and costing a good deal of money, are far from being satisfactory to a man who has the proper |
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