Coordinated motion marine lifting device

US6082947A · kind A · utility

Inventor

• James E. Adamson · West Palm Beach, US

Key dates

• Filing date: Aug 17, 1999
• Grant date: Jul 4, 2000
• Expiry date: Aug 17, 2019

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B66D1/52
• WIPO field: Handling
• WIPO sector: Mechanical engineering

Abstract

This invention is drawn to a device for transporting cargo between a source position and a destination position utilizing a fixed crane-type device, e.g. an A-Frame, including a pivotal sub A-Frame in conjunction with a heave compensating assembly to which a main lifting cable is attached. The bulk of the lifting capacity is derived from a primary power source mechanically linked to the main lifting cable. As the source and destination positions move relative to each other, compensation for this motion is obtained via the coordinated reciprocal movement of an extensible connector, e.g. a wire rope and a lifting device mechanically linked between the main A-Frame and sub A-Frame, which is operative in response to sensory data input to the power unit's controller. The coordinated reciprocal motion acts to adjust the instantaneous load position thereby neutralizing the relative movement between the source position and destination position. The direct compensation provided by the interaction of the sub A-Frame, extensible connector and lifting device assembly provide enhanced neutralization of relative movement in either an active or passively controlled environment.