. Watch and clock escapements; . ub-tooth lever escapement is really the most complicatedescapement made. We mean by this that there are more factorsinvolved in the problem of designing it correctly than in any otherknown escapement. Most—we had better say all, for there areno exceptions which occur to us—writers on the lever escapementlay down certain empirical rules for delineating the several parts, The Detached Lever Escapement. 33 without giving reasons for this or that course. For illustration, itis an established practice among escapement makers to employtangential lockings, as we expla
. Watch and clock escapements; . ub-tooth lever escapement is really the most complicatedescapement made. We mean by this that there are more factorsinvolved in the problem of designing it correctly than in any otherknown escapement. Most—we had better say all, for there areno exceptions which occur to us—writers on the lever escapementlay down certain empirical rules for delineating the several parts, The Detached Lever Escapement. 33 without giving reasons for this or that course. For illustration, itis an established practice among escapement makers to employtangential lockings, as we explained and illustrated in Fig. 16. Now, when we adopt circular pallets and carry the locking faceof the entrance pallet around to the left two and a half degrees,the true center for the pallet staff, if we employ tangent lockings,would be located on a line drawn tangent to the circle a a from itsintersection with the radial line A k, Fig. 21. Such a tangent isdepicted at the line s /. If we reason on the situation, we will see. Fig. 31 that the line A k is not at right angles to the line s I; and, con-sequently, the locking face of the entrance pallet E has not reallythe twelve-degree lock we are taught to believe it has. We will not discuss these minor points further at present, butleave them for subsequent consideration. We will say, however,that we could locate the center of the pallet action at the smallcircle B above the center B, which we have selected as our fork-and-pallet action, and secure a perfectly sound escapement, withseveral claimed advantages. Let us now take up the delineation of the exit pallet. It isvery easy to locate the outer angle of this pallet, as this must besituated at the intersection of the addendum circle i and the arc g,and located at 0. It is also self-evident that the inner or locking 34 Watch and Clock Escapements. angle must be situated at some point on the arc h. To determinethis location we draw the line B c from B (the pallet center) thr
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