Dual spring rate damper

US8181755B2 · kind B2 · utility

Assignee

• Textron Innovations Inc. · US

Inventors

• Frank B. Stamps · Colleyville, US
• David A. Popelka · Colleyville, US
• Michael R. Smith · Colleyville, US
• Christopher M. Bothwell · Grapevine, US
• Lawrence M. Corso · Keller, US
• James L. Braswell, Jr. · Colleyville, US
• Ernst C. Schellhase · Fort Worth, US
• Charles Hollimon · Oosterdijk, US
• Thomas J. Newman · Midlothian, US
• Bryan Kenneth Baskin · Arlington, US
• Thomas C. Campbell · Wichita Falls, US
• Daniel Bryan Robertson · Southlake, US

Key dates

• Filing date: Aug 27, 2004
• Grant date: May 22, 2012
• Expiry date: Jan 4, 2026

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F16F2230/30
• WIPO field: Mechanical elements
• WIPO sector: Mechanical engineering

Abstract

A damper has a piston having an axis, an outer surface, and opposing ends. Elastomeric seals are in sealing contact with the outer surface of the piston, the seals being coaxial with the piston and limiting movement of the piston to a path along the axis of the piston. The seals also define fluid chambers adjacent the ends of the piston. A primary passage communicates the fluid chambers, and a selectively switchable valve for controls a flow of fluid from one of the chambers to another of the chambers through the primary passage. When the flow of fluid through the primary passage is permitted, movement of the piston is resisted by a first spring rate due to a shear force required to cause shear deflection of the seals. When the flow of fluid through the primary passage is restricted, movement of the piston is resisted by a second spring rate due to a fluid force required to cause bulging deflection of the seals.