Cross Leveling Fixture.
Description. The cross leveling fixture (fig. 10-9) is made from heavy components, mainly cast iron, to reduce
vibration and maintain accurate angular settings. Two large circular scales, graduated in degrees, form part of the
elevation and cross leveling mechanisms of the fixture. The axes of these mechanisms lie in a horizontal plane and are
fixed at right angles to each other. Each mechanism may be displaced independently upward or downward by means of
worm and wormwheel movements actuated by the handwheel. Angular settings of either mechanism may be refined to
minutes of arc by means of the vernier scales which form the indexes for the circular scales.
Use. The cross level fixture is used for the adjustment and inspection of various fire control mounts and
quadrants such as the M21A1 Telescope Mount, M145 Telescope Mount, and the M15 Elevation Quadrant. The fixture
was designed for checking the accuracy of elevation mechanisms, angle-of-sight mechanisms, and the setting of level
Figure 10-9. Cross Leveling Fixture.