Modern Mechanical Engineering Vol-I

THE ESSENTIALS OF ECONOMICAL MACHINING 207

different kinds of operations are performed, or the jig plates may be changed
for the operations of drilling or milling. The fixture may be rigid, or it
may be made movable so as to present different faces of the work to the

FLANGEHQLE JIGS
SIDE VI£W CD

PLAN OF TOP

PLAN OF BOTTOM

Fig. 42 .—Fixture for holding Feed-pump Check Valve

tools. Stop pins and locking devices provide for precise settings on one or
on several pieces of work held in tandem.
Example of an Open Fixture.—Fig. 40 illustrates a plunger for a
sensitive feed lever, and fig. 41 an open fixture for holding six levers while
their ends are being milled to bevels. This is by Messrs. James Archdale
& Co., Ltd., Birmingham. The levers rest in vees at one end, in which they