Coordinate measuring machine guideway composite structure and method of manufacture

US6202316A · kind A · utility

Inventors

• Timothy J. Swift · Gilbert, US
• John Hunter · South Holland, US

Key dates

• Filing date: Apr 14, 1998
• Grant date: Mar 20, 2001
• Expiry date: Apr 14, 2018

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S33/11
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A composite structure for use in a coordinate measuring machine (CMM) includes a metallic material joined to a non-metallic material, wherein each material possesses a coefficient of thermal expansion (CTE) less than or equal to 6.1.times.10.sup.-6 cm/cm/.degree. C. The metallic material may be INVAR, an alloy of iron and nickel, and the non-metallic material may be carbon fiber reinforced composite. Also, the metallic material may be in the shape of a space frame with the non-metallic material in the shape of stiffeners adhered to the space frame. The modulus of elasticity of the combined space frame and stiffeners is preferably greater than 140 GPa. The space frame may be a modified I-beam with reinforcing structures and mass-reducing cutouts. The stiffener may be a square tube, wherein one stiffener is adhered to each I-beam flange of the space frame. The stiffeners are ground and lapped to produce bearing tracks of high precision for air bearings to traverse. Additionally, a method for fabricating a CMM includes the steps of assembling and/or fabricating the materials and structures described above.