Position Sense and Automatic Stop Device
Original Publication Date: 1978-Apr-01
Included in the Prior Art Database: 2005-Feb-20
For controlling the movement of a semiconductor wafer or other flat element 1 on an air track 2, such as braking or stopping, an air control device 3, as shown in the drawing, comprises a cylindrical body 4 with an air supply port 5 and a static pressure chamber 6. The chamber 6 communicates with the port 5 via opening 7 and with an aspirator slot 8 via jet port 9. The aspirator slot 8 is disposed in the air track 2 between pressure ports 10 and suction ports (not shown) which create the air film for supporting the wafer 1. The supply port 5 is positioned in the air track 2 at the desired stopping point of the wafer 1. Arrows 11 show the air flow through the air control device 3.