DEVICE FOR MEASUREMENT OF RADIUS OF CURVATURE OF SURFACE OF PART Russian patent published in 1994 - IPC

FIELD: measurement technology. SUBSTANCE: device for measurement of small radius of curvature from 15 to 40 mm has source of light, capacitor, collimator composed of lens and slit diaphragm mounted in its front focal plane, opaque screen with one narrow slit, carriage moving perpendicular to optical axis of collimator with the aid of electric motor through pickup of value of travel, two measurement branches consisting of lenses and coordinate-sensitive photodetectors mounted in rear focal planes of lenses, unit for information processing, indicator unit and digital printing unit. Lens of collimator forms wide beam of parallel rays from which slit of opaque screen cuts narrow beam of parallel rays which is incident on checked part and is reflected from it. With movement of checked part perpendicular to optical axis distance from vertex of part to point of incidence on it of beam of rays and angle of its reflection change. At certain distance angle of reflection grows equal to 90 deg and image of slit becomes symmetric to line of separation of photodetector. Reading from pickup of value of travel is memorized. With further movement of part beam of rays passes through vertex of part and is reflected to other side at angle of 90 deg to optical axis of collimator building image of slit of collimator in symmetry to line of separation of second photodetector. Reading from pickup of value of travel is memorized. Difference of readings produces distance between incident beams of rays when they are reflected at angles of 90 deg. Radius of curvature of checked part is determined by angle and distance. EFFECT: improved accuracy of measurement of small radii of curvatures under automatic mode. 1 dwg