The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 25, 2003
Filed:
Oct. 27, 2000
Chen-Fu Liao, Maple Grove, MN (US);
Paul B. Gladen, Golden Valley, MN (US);
Keith Hochhalter, Minnetrista, MN (US);
Tol-O-Matic, Inc., Hamel, MN (US);
Abstract
A precision servo control system for a pneumatic actuator has a piston positionable over a stroke of the pneumatic actuator using a supply of pressurized gas. A brake and a sensor system are connected to the actuator and to the servo control system. The servo control system operates to initiate the forward thrust from the pressurized gas to move the piston along the stroke. When a braking point along the stroke is determined, the servo control system initiates a reverse thrust from the pressurized gas while maintaining the forward thrust and simultaneously begins to selectively apply the brake to stop the piston within a predetermined tolerance of a desired stopping position. The precision servo control system is easily programmable in a manner similar to that of a control system for electrical actuators. The precision servo control system can maintain the predetermined tolerance even under changing loads, long stroke lengths or vertically oriented stroke directions. The precision control servo system preferably utilizes simple directional valves, instead of complex and expensive servo valves, to regulate the pressurized gas. The precision servo control system achieves positional accuracy to a predetermined tolerance that is a fixed value, regardless of the stroke length.