Modern Mechanical Engineering Vol-I

224

THE MACHINE-SHOP

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milling. Generally the bed is of the lathe type, and receives the saddle on
which the work-holding table has a cross-traverse movement. In some cases
the bed resembles that of a planing machine, along which the work table
traverses, this giving a longer range of feed than the other. As the table
cannot be elevated, vertical movements are imparted to the spindle, which
slides in its bearings in or on the faces of housings fixed at the left-hand end

Fig. 59.—Vertical-spindle Machine

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of the bed. An arbor support is provided in a tail block at the right hand,
adjustable along the bed.
The Pillar and Knee Machine.—Also frequently termed a horizontal
spindle machine, this has a hollow column that carries a headstock on top,
and a knee on one face, which receives the work table and its slides. All
vertical adjustments are imparted to the knee. Machines are plain or
universal, the first being restricted to rectangular movements only, that of
the table along its saddle, that of the table alone, longitudinally, and that of
the knee vertically. The second includes in addition a spiral head, an index