The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 07, 1988
Filed:
Jul. 23, 1987
Dennis H Sansome, West Midlands, GB;
Gerald M Jones, Bewdley, GB;
National Research Development Corporation, London, GB;
Abstract
A variable-geometry plug for use in the plug drawing of tube or other elongated hollow stock. The plug comprises first and second coaxial and relatively-movable parts which co-operate with a deformable annular sealing ring. With the two parts so disposed that the ring is relaxed, the plug can be inserted easily into the undrawn stock. In use, the two parts are caused to move relative to each other, so deforming the ring that it seals an annular clearance between the plug and the undrawn stock. If lubricant is then provided at the upstream face of the seal, the movement of the stock over the seal then tends to draw that lubricant forward across the seal by hydrodynamic action, so tending to fill the clearance with that lubricant at an enhanced pressure. Plugs are described in which this hydrodynamic pressurization is augmented by fluid under pressure supplied direct to the clearance through conduits including passages formed through the body of the plug. Plugs connected to solid bars and flexible leads, and also truly 'floating' plugs no such connection, are described.