Sandy B Lee

US Patent:

20190376531, Dec 12, 2019

Filed:

Feb 12, 2018

Appl. No.:

16/485406

Inventors:

- Tokyo, JP
Sandy Lee - Dublin CA, US
Gaurav Keswani - Foster City CA, US
Rocky Mai - San Mateo CA, US

International Classification:

F15B 9/08
F15B 11/00
F15B 11/042
F15B 11/028
F15B 13/04
F15B 9/03

Abstract:

A stage assembly () includes a stage (), and a fluid actuator assembly () that moves the stage (). The fluid actuator assembly () includes a piston housing () that defines a piston chamber (); (ii) a piston () that separates the piston chamber () into a first chamber (A) and a second chamber (B); (iii) a supply valve (C) that controls the flow of the working fluid () into the first chamber (A); and (iv) an exhaust valve (D) that controls the flow of the working fluid () out of the first chamber (A). The supply valve (C) has a supply orifice (G) having a supply orifice area, and the exhaust valve (D) has an exhaust orifice (G) having an exhaust orifice area. Moreover, the supply orifice area is different from the exhaust orifice area. Further multiple valves of different sizes can be used in combination for the supply and exhaust for each chamber (A), (B).