FORM MEASURING INSTRUMENT

• US 20140237834A1
• Filed: 02/26/2014
• Published: 08/28/2014
• Est. Priority Date: 02/28/2013
• Status: Active Grant

• Current Assignee: Mitutoyo Corporation
• Original Assignee: Mitutoyo Corporation
• Inventors: Matsumiya, Sadayuki, Hidaka, Kazuhiko
• Granted Patent: US 9,285,201 B2
• Time in Patent Office: Days
• US Class Current: 33/503
• CPC Class Codes: G01B 3/008 Arrangements for controlling the measuring force
• CPC Class Codes: G01B 5/20 for measuring contours or curvatures
• CPC Class Codes: G01B 5/28 for measuring roughness or irregularity of surfaces
• CPC Class Codes: G01B 7/28 for measuring contours or curvatures
• CPC Class Codes: G01B 7/34 for measuring roughness or irregularity of surfaces

Abstract

A form measuring instrument includes: a body; a movable member including: a stylus holder being rotatably supported by the body; a stylus being held by the stylus holder; and a tip being provided at an end of the stylus and being contactable with a workpiece surface; a measurement-force-applying unit being adapted to generate a rotation force acting on the stylus holder to bring the tip of the stylus into contact with the workpiece surface; a displacement detector being provided to a portion of the stylus holder to detect a displacement of the stylus holder resulting from a rotation thereof; and a vibration generator being adapted to apply vibration to the stylus holder.

Claims

1. A form measuring instrument comprising:

a body;

a movable member comprising;

a stylus holder being rotatably supported by the body;

a stylus being held by the stylus holder; and

a tip being provided at an end of the stylus and being contactable with a workpiece surface;

a measurement-force-applying unit being adapted to generate a rotation force acting on the stylus holder to bring the tip of the stylus into contact with the workpiece surface;

a displacement detector being provided to a portion of the stylus holder to detect a displacement of the stylus holder resulting from a rotation thereof; and

a vibration generator being adapted to apply a vibration to the stylus holder.

2. The form measuring instrument according to claim 1, wherein the vibration applied by the vibration generator comprises a first vibration that makes the stylus holder move around a turn shaft thereof.

3. The form measuring instrument according to claim 2, wherein the vibration applied by the vibration generator comprises a bidirectional vibration comprising:

the first vibration making the stylus holder move around the turn shaft thereof; and

a second vibration in a direction intersecting with a direction of the first vibration.

4. The form measuring instrument according to claim 1, wherein

the vibration generator is adapted to vibrate the stylus holder at a frequency higher than a natural frequency of the movable member, and

the displacement detector is adapted to output only a frequency component lower than the natural frequency of the movable member taken from a signal representing the displacement detected at the portion of the stylus holder.

5. The form measuring instrument according to claim 1, wherein the vibration generator is adapted to vibrate a section defined from the turn shaft of the stylus holder to the tip of the stylus.

6. The form measuring instrument according to claim 5, wherein the vibration generator is adapted to vibrate the stylus holder.

7. The form measuring instrument according to claim 1, wherein the displacement detector is adapted to detect a displacement of a portion of the stylus holder opposite to the tip of the stylus across the turn shaft.