Cased Instruments, Continued
Proportional dividers transfer measurements from one scale to another and
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
Figure 2-19 shows a set of proportional dividers.
Figure 2-19. Proportional 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
Figure 2-20 shows a set of common dividers.
Figure 2-20. Common dividers.
Continued on next page