528 Chapter 16 Engineering Drawings and Symbols
Next, we will extrude the profile in the normal direction, as shown in Figure 16.29.
We then create the block and the holes. In order to create the holes, first we create two solid
cylinders and then use the Boolean operation to subtract the cylinders from the block. Finally,
we add the new block volume to the volume, which we created by the extrusion method, as in
Figure 16.30.■Figure 16.29 Extruded profile.
Block
Holes
■Figure 16.30 The solid model of the bracket.
16.8 Why Do We Need Engineering Symbols?
The symbols in Figure 16.31 are a “language” used by engineers to convey their ideas, their
solutions to problems, or analyses of certain situations. As engineering students you will learn
about the graphical ways by which engineers communicate among themselves. In this section,
we will discuss the need for conventional engineering symbols as a means to convey informa-
tion and to effectively communicate to other engineers. We will begin by explaining why there
exists a need for engineering signs and symbols. We will then discuss some common symbols
used in civil, electrical, and mechanical engineering.
Almost all of you have a driver’s license by now; perhaps you even own a car. If this is the
case, then you are already familiar with conventional traffic signs that provide valuable infor-
mation to drivers. Examples of traffic signs are shown in Figure 16.32. These signs are designed
and developed, based on some acceptable national and international standards, to convey infor-
mation not only effectively but also quickly. For example, a stop sign, which has an octagon
shape with a red background, tells you to bring your car to a complete stop.
A sign that signals a possibly icy road ahead is another example that warns you to slow
down because the road conditions may be such that you may end up in a hazardous situation.
That same information could have been conveyed to you in other ways. In place of the sign62080_16_ch16_p504-549.qxd 5/22/10 12:31 AM Page 528
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