Expansion joint with two sealing elements

US5232251A · kind A · utility

Inventor

• John Gaughan · Los Angeles, US

Key dates

• Filing date: Mar 18, 1991
• Grant date: Aug 3, 1993
• Expiry date: Mar 18, 2011

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S285/91
• WIPO field: Mechanical elements
• WIPO sector: Mechanical engineering

Abstract

This invention provides an expansion joint that uses a flexible sealing element in conjunction with a packed seal in a manner that allows a reduction in break-away forces and permits continued operation of the joint after a failure of the bellows or bellows attachment point. The expansion arrangement includes a flexible sealing element, usually in form of a bellows, and a containment chamber in communication with the exterior portion of the flexible sealing element or bellows and an interior portion of the packed seal. The containment chamber has an opening that permits relative movement between the ends of the expansion joint and is sealed by the packed seal. In the event of a bellows failure, the packing material acts to restrict or prevent leakage from the containment chamber to the outside environment. Thus, in normal operation the flexible sealing element provides a leakproof seal and the packing serves as a backup seal which will in all cases restrict leakage from the bellow to the outside environment and, depending on the amount of force initially applied to the packing, can stop any leakage from the bellow as soon as failure occurs. After failure of the sealing element the …