We have now explained how we can delineate a tooth or
pallet at any point of its angular motion, and will next explain how to
apply this knowledge in actual practice.
PRACTICAL PROBLEMS IN THE LEVER ESCAPEMENT.
To delineate our entrance pallet after one-half of the engaged tooth has
passed the inner angle of the entrance pallet, we proceed, as in former
illustrations, to establish the escape-wheel center at _A_, and from it
sweep the arc _b_, to represent the pitch circle. We next sweep the
short arcs _p s_, to represent the arcs through which the inner and
outer angles of the entrance pallet move. Now, to comply with our
statement as above, we must draw the tooth as if half of it has passed
the arc _s_.
To do this we draw from _A_ as a center the radial line _A j_, passing
through the point _s_, said point _s_ being located at the intersection
of the arcs _s_ and _b_. The tooth _D_ is to be shown as if one half of
it has passed the point _s_; and, consequently, if we lay off three
degrees on each side of the point _s_ and establish the points _d m_, we
have located on the arc _b_ the angular extent of the tooth to be drawn.
Pages:
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184