Cased Instruments, Continued
Proportional
Proportional dividers transfer measurements from one scale to another and
dividers
divide lines and circles into equal parts. They consist of two legs of equal
length joined by a moveable pivot. This pivot is a rack-and-gear movement
secured by a thumb nut. There is a series of scales on the divider face
ranging from 1 to 11.5. Divider points are made of hardened steel.
Protect divider points when they are not in use. Keep the dividers clean and
wipe them with a light oil cloth after use, Do not oil the movement on
proportional dividers.
Figure 2-19 shows a set of proportional dividers.
Figure 2-19. —Proportional dividers.
Dividers
Use a set of dividers to step off equal distances, to transfer measurements, or
to divide a line into equal lengths. Dividers have two legs of equal length
terminating in needlepoints. Above the needlepoints is a hinge to help the leg
maintain perpendicularity with the drawing surface. Dividers are joined at
the top.
Figure 2-20 shows a set of common dividers.
Figure 2-20. —Common dividers.
Continued on next page
2-20
