South Bend mills could be ordered with a power feed for the quill
as an option.  The "rube goldberg" solution was a hydraulic feed
including rapids for the short 4" quill stroke.  As acquired, this
one had the feedworks installed, but no hydraulic power supply.
The orginal took up most of a good sized cabinet mounted to the 
left side & base of the mill.  After dithering about it for some
time, curiosity about how well the device worked got the best of
me, and I made a power unit out of a Saginaw power steering pump.
The pump needs to have the pressure reduced to 300PSI or less.
SB counted on hard stops as the adjustable limits.  Too much 
pressure will shear the key to the quill rack gear at the limits
(or break teeth).  Another factor is that it seems preposterous
to use more than 1/2HP dedicated to the quill feed:  The spindle
motor is only 3/4HP!  300PSI, reduced flow, and 1/2HP seem to 
work fine.  The unit works as it should; and is a hoot to operate.
Infinitely variable up/down feed rates, and rapids either direction
to avoid having to reset the feed rate in use, say for a multiple 
pass boring operation.