Patent ID: 6463671
Filing Date: 2002-10-15
Classification: G01B

Abstract:
A micrometer comprising:an approximately U-shaped frame; an anvil held on one end of the frame; a spindle screwed to an other end of the frame through a retainer sleeve and movable toward and away from the anvil; a thimble secured to the spindle and fitted to an outer circumference of the retainer sleeve; an operation sleeve rotatable relative to the spindle, the operation sleeve integrally having, on an outer side of an end of said operation sleeve remote from an end opposing the anvil, a first operation section with a smaller diameter than the diameter of the retainer sleeve and a second operation section fitted to an outer circumference of the thimble; and a constant-force device provided on either between the first operation section of the operation sleeve and an outer end of the spindle remote from the anvil or between the second operation section of the operation sleeve and the outer circumference of the thimble, the constant-force device idly spinning when a more than predetermined load is applied to the spindle.