If, however, we removed the engaging tooth, which we have just conceived
to be at _c_, to the point _k_ on the arc _a' a'_, Fig. 88, the pallet
center _D_ would then represent a tangential locking, and a neutral
pallet face would coincide with the radial line _A k'_; and a locking
face with twelve degrees draw would coincide nearly with the line _l_.
Let us next analyze what the effect would be if we changed the pallet
center to _h'_, Fig. 88, leaving the engaging tooth still at _k_. In
this instance the line _l l_ would then coincide with a neutral locking
face, and to obtain the proper draw we should delineate the locking face
to correspond to the line _k n_, which we assume to be twelve degrees
from _k l_.
It is not to be understood that we insist on precisely twelve degrees
draw from a neutral plane for locking faces for lever pallets. What we
do insist upon, however, is a "safe and sure draw" for a lever pallet
which will hold a fork to the banks and will also return it to such
banks if by accident the fork is moved away.
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