on which the bed is carried can be rotated on a pin to present different faces
to the work. It is also detachable. Fig. 56 shows the same bed turned round
90° to have the cylinder end faced and bored to receive the liner. After
this, an edge-mill machines the water inlet and outlet and cam shaft
Vertical-spindle Machines.—These are the most popular types at
present for dealing with motor cylinders and those of the smaller gas engines.
The spindles are massive to enable them to withstand heavy cuts in bores
Fig. 55.—Boring and facing Crank-shaft Bearings of Gas-engine Bed
(Pearn-Richards Horizontal Combined Machine)
that range, say, from 4 to 6 in., and in lengths up to about 16 in. The
analogue of this class of spindle is that of the horizontal snout boring machine,
introduced originally to deal with cylinders of small bores and having either
one or two spindles. This is being supplanted by the vertical design, to
which multi-spindles are more readily fitted, while the workman has a better
view of the operations, and the cuttings fall clear away at once instead of
choking the action of the tools. It is also easier to design and handle fixtures
for the vertical spindle machines than for the others.
With the rapid extension of automobile work the vertical-spindle machines
have been subject to many changes and improvements. Single-spindle
machines are ranged in gangs, three or four comprising a working unit.
The cylinder, held in a suitable fixture, is rough-bored under one spindle,