Linear ejection underwater charge launcher

US4117780A · kind A · utility

Assignee

• Western Geophysical Company of America · US

Inventor

• John C. Mollere · Nassau Bay, US

Key dates

• Filing date: Jun 10, 1977
• Grant date: Oct 3, 1978
• Expiry date: Jun 10, 1997

Classification

• Technology area (CPC G): Physics
• CPC primary: G01V1/393
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

The underwater charge launcher linearly ejects a small, water-propelled explosive charge into the water from the open end of an ejection barrel trailed in the water behind a seismic exploration vessel. The charge is detonated, after a one to two-second delay, when a percussion-ignitable delay cap in the end of the charge impacts a firing member positioned adjacent the open end of the ejection barrel. The firing member includes a firing pin mounted on a rotatable, spring-biased striker plate having a U-shaped rim. When a charge is ejected from the barrel, the primer cap impacts the firing pin. The kinetic force of the ejected charge acting against the firing pin overcomes the moment of inertia of the striker plate, causing it to rotate the firing pin out of the path of the charge. The charge is supported and guided by the unobstructed portion of the U-shaped rim of the striker, as the charge is ejected out of the launcher. After a preset delay, the charge detonates when it is a safe distance from the launcher. Once the charge is clear of the firing member, a bias spring returns the striker plate to its rest position.