SPHERICAL-FORM MEASURING APPARATUS

• US 20110173830A1
• Filed: 01/19/2011
• Published: 07/21/2011
• Est. Priority Date: 01/20/2010
• Status: Active Grant

• Current Assignee: Mitutoyo Corporation
• Original Assignee: Mitutoyo Corporation
• Inventors: Hagino, Takeshi, Yokoyama, Yuichiro
• Granted Patent: US 8,356,417 B2
• Time in Patent Office: Days
• US Class Current: 33/553
• CPC Class Codes: G01B 5/008 using coordinate measuring machines
• CPC Class Codes: G01B 5/201 for measuring roundness
• CPC Class Codes: G01G 21/20 for precision weighing apparatus

Abstract

A spherical-form measuring apparatus 10 which efficiently measures the sphericity and the form of a sphere to be measured with use of the mechanism of a roundness measuring machine, including:

• • a turntable 14;
  • a probe 22 for measuring a contour of a sphere to be measured on an equatorial plane parallel to a surface of the turntable 14, associated with rotation of the turntable 14; and
  • a holding unit 24 mounted on the turntable 14, for holding the sphere to be measured 30;
  • wherein the holding unit 24 positions the center of the sphere to be measured 30 on a rotational axis of the turntable 14, and holds the sphere to be measured 30 so that the sphere is rotatable about an inclined axis which passes the center of the sphere and is inclined at the angle in the range of −5 degrees-+5 degrees centered on the angle where the sine is 1√3 (1 divided by the square root of 3) against the surface of the turntable 14.

Claims

1. A spherical-form measuring apparatus, comprising:

a turntable;

a probe for measuring a contour of a sphere to be measured on an equatorial plane parallel to a surface of the turntable, associated with rotation of the turntable; and

a holding unit mounted on the turntable, for holding the sphere to be measured;

wherein the holding unit positions the center of the sphere to be measured on a rotational axis of the turntable, and holds the sphere to be measured so that the sphere to be measured is rotatable about an inclined axis which passes the center of the sphere and is inclined at an angle in the range of −

5 degrees-+5 degrees centered on an angle where a sine is 1/√

3 (1 divided by the square root of

     3) against the surface of the turntable.

2. The apparatus according to claim 1, wherein a sphericity of the sphere to be measured is measured in a way that the holding unit rotates the sphere to be measured by 120 degrees repeatedly about the inclined axis and contour measurement on the equatorial plane of the sphere is performed at every rotated position.