Figure 7-19.--The wide range divider.
allows you to index divisions from 2 to 400,000. The
As with the standard dividing head, the large
wide range divider (fig. 7-19) consists of a large index
index crank rotates the spindle in the ratio of 40 to 1.
Therefore, one complete turn of the large index crank
plate and a small index plate, both with sector arms
rotates the dividing head spindle 1/40 of a turn, or 9°.
and a crank. The large index plate (A, fig. 7-19) has
By using the large index plate and the crank, you can
holes drilled on both sides and contains 11 circles of
index in the conventional manner. Machine operation
holes on each side of the plate. The number of holes
is the same as it is with the standard dividing head.
in the circles on one side are 24, 28, 30, 34, 37, 38, 39,
41, 42, 43, and 100. The other side of the plate has
circles containing 46, 47, 49, 51, 53, 54, 57, 58, 59,
62, and 66 holes. The small index plate has two
rotated, the large index crank remains stationary, but
circles of holes and is drilled on one side only. The
the main shaft that drives the work revolves in the
outer circle has 100 holes and the inner circle has 54
ratio of 1 to 100. This ratio, superimposed on the 40
to 1 ratio between the worm and worm wheel
The small index plate (B, fig. 7-19) is mounted on
in the ratio of 4,000 to 1. This means that one
complete revolution of the spindle will require 4,000
which is built into the index crank (F, fig. 7-19) of the
turns of the small index crank. Turning the small
large plate. As the index crank of the large plate is
crank one complete turn will rotate the dividing head
rotated, the planetary gearing assembly and the small
spindle 5 minutes, 24 seconds of a degree. If one hole
index plate and crank rotate with it.
of the 100-hole circle on the small index plate were to