Power tong

US6082224A · kind A · utility

Assignee

• Weatherford/Lamb, Inc. · US

Inventors

• Gary McDaniels · Lafayette, US
• Patrick Cummings · Lafayette, US
• Michael Hayes · Belleville, US
• Steven Albright · Houston, US
• Bernd-Georg Pietras · Großburgwedel, DE
• Jorg Schulze-Beckinghausen · Garbsen, DE
• Andreas Carlsson · Skövde, SE

Key dates

• Filing date: Feb 19, 1997
• Grant date: Jul 4, 2000
• Expiry date: Feb 19, 2017

Classification

• Technology area (CPC E): Fixed Constructions
• CPC primary: E21B19/164
• WIPO field: Civil engineering
• WIPO sector: Other fields

Abstract

A new power tong for rotating tubular members for make-up (connection) and break-out (disconnection) operations. In one aspect such a tong has at least one movable jaw with a smooth surface gripping element thereon and pre-load apparatus for applying a pre-load force to a movable jaw so that the jaw does not slip on a tubular to be rotated and so it does not mark or damage the tubular. In one aspect the pre-load apparatus includes a first pre-load device at one end of a movable jaw for breakout operations and a second pre-load device at another end of the jaw for make-up operations. In one aspect a power tong which has unique smooth surfaced jaw inserts made, e.g., of aluminum. In one aspect a single pivotable pre-load cylinder, fixed to rotary, pivots for pivotable connection to one jaw or the other. This can be done manually or a powered smaller piston/cylinder may be used to pivot the pre-load cylinder. In one aspect a jaw unit which comprises a jaw holder and a jaw movable with respect to said jaw holder, characterized in that said jaw is slidably mounted on said jaw holder.