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 32 of 243 (13%)
page 32 of 243 (13%)
![]() | ![]() |
|
examples, by first assuming the center of the escape wheel at _A_, and
with the dividers set at five inches sweeping the arc _a a_. Through _A_ we draw the vertical line _A B'_. On the arc _a a_, and each side of its intersection with the line _A B'_, we lay off thirty degrees, as in former drawings, and through the points so established on the arc _a a_ we draw the radial lines _A b_ and _A c_. From the intersection of the radial line _A b_ with the arc _a_ we draw the line _h h_ at right angles to _A b_. Where the line _h_ intersects the radial lines _A B'_ is located the center of the pallet staff, as shown at _B_. Inasmuch as we decided to let the pallet utilize five degrees of escape-wheel action, we take a space of two and a half degrees in the dividers, and on the arc _a a_ lay off the said two and a half degrees to the left of this intersection, and through the point so established draw the radial line _A g_. From _B_ as a center we sweep the arc _d d_ so it passes through the point of intersection of the arc _a_ with the line _A g_. [Illustration: Fig. 20] We again lay off two and a half degrees from the intersection of the line _A b_ with the arc _a_, but this time to the right of said intersection, and through the point so established, and from _B_ as a center, we sweep the arc _e_. From the intersection of the radial line _A g_ with the arc _a_ we lay off to the left five and a half degrees on said arc, and through the point so established draw the radial line _A f_. With the dividers set at five inches we sweep the short arc _m_ from _B_ as a center. From the intersection of the line _h B h'_ with the arc _m_ we lay off on said arc and above the line _h'_ four and a half degrees, and through the point so established draw the line _B j_. We next set the dividers so they embrace the space on the radial line _A b_ |
|