When measuring spindle 1 is raised, frame a, rigidly secured to the spindle, and knife edge 2 are also raised. This enables spring 4 to turn member 3 on fixed knife edge 5. The deflection of member 3 from its horizontal position is indicated by hand 6 on scale b. Spring 7 holds measuring spindle 1 constantly against workpiece d being measured.
$466$SL,M$