P inio n 7, on which hand d is rig id ly mounted, rotates about
fixed axis A and meshes w ith segment gear a, tu rning about
fixed axis В of lever 3. The size of workpiece 1 is indicated on
scale b by hand d. The position of hand d depends upon the positions
of lever 3 and measuring spindle 2, which contacts workpiece
1 and engages lever 3 w ith a lug. A t the m in im um lim it
of size of workpiece 1, spindle 2 moves downward, turning lever
3 clockwise and closing a circuit by contacting screw 4. A t the
m ax im um lim it of size, spindle 2 moves upward so that spring 5
turns lever 3 counterclockwise, closing a second circuit by contacting
screw 6. The two circuits closed at screws 4 and 6 are
sig na lling circuits th at enable over- and undersize workpieces
to be rejected.
$4382$SmE,M$