| 摘要 |
PURPOSE:To eliminate the friction parts and to improve both the durability and performance, by forming air nozzles to the inner sides of the base part and the outer circumference part of an adverse U-shaped turntable fitted to an inner block and then forming an air path. CONSTITUTION:A gap 5e is produced between a turntable 1 and the upper surface of a glass plate 2 owing to the pressure of the air which is blown off vertically from a chamber 5 to the inner side of the base part 1a of the table 1 through a nozzle 7a via holes 4g and 7b. The air pressure in the gap 5e floats the table 1, and the air flows to the outside through a hole 3b via the gap 5a. While the compressed air blown off through a nozzle 4a in the radius direction fills a depressed part 4b and presses the inner circumferential part of the outer circumferential part 1b of the table 1 to be blown off via gaps 5f and 5a. Each pair of parts 4b are set symmetrical in the diameter direction, and therefore the table 1 is supported in its diameter direction with good balance. Thus, eliminates the friction parts are eliminated and both the durability and performance of a turntable are improved. |
