LATHE OPERATIONS - OD1645 - LESSON 1/TASK 1
and a hollow headstock spindle for feeding bar stock into the machine, or
may use a universal scroll chuck for swinging the workpiece. The size of
the horizontal turret lathe is usually given as the diameter of bar stock
that can be fed into the lathe through the headstock spindle. The size can
also be classified by the swing. The turret of the turret lathe is usually
power operated.
It contains an indexing mechanism for bringing the tools
(held on its six faces) against the workpiece in a preselected order.
Separate feed stops are provided for each face of the turret. A quick hand-
indexing four-sided turret is commonly mounted on the front of the cross-
slide, and a holder for one or more tools often is mounted on the rear. The
cross-slide may be either hand or power operated.
e.
Special Purpose Lathes.
(1) General.
Some lathes have characteristics that enable them to do
certain work well.
Some of these lathes are of the heavy-production type
where large numbers of identical parts must be produced to make the
operation more economical. Other special purpose lathes are specialized for
machining specific items and cannot be adapted to the common types of lathe
operations.
(2) Bench-type Jeweler's Lathe.
The bench-type jeweler's lathe is
actually a miniature engine lathe designed for the precision machining of
small parts. The usual jeweler's lathe contains a collet-type chuck, lead
screw, change gears for threading operations, and a precise manual
crossfeed.
Controls and feeds are calibrated in smaller increments than
with the engine lathe and, as a result, workpieces of small dimensions can
be machined to a great degree of accuracy.
The jeweler's lathe is belt
driven by an independent motor which can be mounted above or behind the
lathe.
(3) Other Special Purpose Lathes.
Other special purpose lathes include
the production lathe, the automatic lathe, the automatic screw machine, the
brakedrum lathe, the crankshaft lathe, the duplicating lathe, the
multispindle lathe, and lathes designed for turning car axles or forming
sheet metal.
7
Previous Page
