Sprocket blank a is clamped coaxially on link 1 which is a segment with teeth exactly like those to be cut on the sprocket blank. Link 2 is clamped rigidly on the milling machine table, and carries pin d which engages the teeth of sprocket segment 1. Link 1 with sprocket blank a turns about axis A of link 4 which, in turn, turns about fixed axis B. The axis of end mill c coincides with that of pin d. When handle e is turned first in one direction and then in the other, link 1 rolls about pin d of link 2 and end mill c mills the required tooth space profile on sprocket blank a. Then blank a is indexed on link 1 by a device (not shown) and the next tooth space is milled, etc.
$2656$PG,FD$