We do not
quote his description or directions for delineation because he refers to
so much matter which he has previously given in the book just referred
to. Besides we cannot entirely endorse his methods of delineations for
many reasons, one of which appears in the drawing at Fig. 84.
[Illustration: Fig. 84]
MORE ABOUT TANGENTIAL LOCKINGS.
Most writers endorse the idea of tangential lockings, and Saunier speaks
of the escapement as shown at Fig. 84 as having such tangential
lockings, which is not the case. He defines the position of the pallet
staff from the circle _t_, which represents the extreme length of the
teeth; drawing the radial lines _A D_ and _A E_ to embrace an arc of
sixty degrees, and establishing the center of his pallet staff _C_ at
the intersection of the lines _D C_ and _E C_, which are drawn at right
angles to the radial lines _A D_ and _A E_, and tangential to the circle
_t_.
Here is an error; the lines defining the center of the pallet staff
should have been drawn tangent to the circle _s_, which represents the
locking angle of the teeth.
Pages:
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160