 Image Number 12 for United States Patent #6408767.
A suspension system (18) for suspending a stage (14) spaced apart from a stage base (12) is provided herein. The suspension system (18) includes a plurality of spaced apart suspension assemblies (20). Each suspension assembly (20) includes a fluid pad (22) and an adaptable section (24). A bearing fluid (48) is directed from the fluid pad (22) to create a fluid bearing (52) between the fluid pad (22) and the stage base (12). The fluid bearing (52) allows for large displacement, frictionless motion along an X axis, along a Y axis and rotation about a Z axis. The adaptable section (24) secures the fluid pad (22) to the stage (14). The adaptable section (24) allows for relative movement between the fluid pad (22) and the stage (14). More specifically, the adaptable section (24) allows for small displacement, low stiffness motion along the Z axis and rotation about the X axis and the Y axis. In summary, the suspension system (18) permits six degrees of freedom motion and provides some vibration isolation along the Z axis.
|