Coordinate measuring machine with improved carriage way arrangement

• Main Authors: RALEIGH; FREDDIE L, HEMMELGARN; THOMAS L
• Format: Patent
• Language: English
• Published: 28.11.1989
• Subjects: MEASURING; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS; MEASURING LENGTH, THICKNESS OR SIMILAR LINEARDIMENSIONS; PHYSICS; TESTING

A coordinate measuring machine (10) of the horizontal arm type having an improved way arrangement for a carriage (40) mounted for movement along one of the orthogonal axes (X) of the machine including a pair of angled upstanding granite way members (24,26) detachably mounted spaced apart atop a granite base member (22), extending parallel to each other and the axis of movement. The way members (24, 26) have inwardly turned opposing overhang portions (28, 30) formed with upper horizontal way surfaces (32,34) and under way surfaces (36,38). The carriage (40) is received in the space between the way members (24,26) and is formed with flanges (42,44) extending over the upper way surfaces (32, 34) with pairs of air bearings (46a,b; 48a,b) interposed. Preload brackets (50,52,54) are attached to the underside of the carriage (40), constructed of a different material to equalize the thermal growth, and have portions (56, 58, 60) extending beneath the under way surfaces (36,38) with pairs of preloading air bearings (62a,b; 64a,b) interposed. Integral pairs of guide legs (66a,b; 68a,b) extend downwardly on either side of a granite guide rail (70) affixed atop the base member (22) with lateral guiding air bearing pairs (76a,b; 78a,b) interposed.