Texas Instruments Corporation

Hydril Company

Jon L Edwards

Mark L Carter

A tubing retrievable surface controlled subsurface safety valve having a rotatable ball-type flow closure element is disclosed. A tubular operator assembly imparts longitudinal movement to the ball greater than the predetermined movement required to effect the desired ball rotation. The ball element is normally maintained by a closing spring arrangement and is rotated open by increased control fluid pressure. Camming slides on the ball rotation pins reduce contact stress during ball operation. A locking sleeve having a longitudinal locking movement greater than the predetermined movement to rotate the ball open is provided. Operating movement of the locking sleeve uncovers a control fluid port for operating a supplemental subsurface valve operably secured with the valve. Prior to activating the locking sleeve to install the supplemental valve, the valve may be controlled by control fluid pressure communicated into an expansible chamber. The chamber is formed by two pairs of seals located on different diameters and at opposite ends of an operator sleeve guide member. The guide member contains both pairs of seals against extrusion from extreme pressure differentials. The seals are pressure energized and the seals of each pair are faced in opposite directions to maintain sealing integrity under all pressure differential operative conditions.

Subsurface safety valve

A switch assembly with reduced number of mechanical parts in conjunction with an improved Hall Effect generator provides a more reliable, longer life switch. In one embodiment, the rocking motion of a rocker member is translated into linear motion to move a magnet relative to the Hall Effect generator. As the rocker member is rotated by pressure applied to the higher of its actuation surfaces, rotation is set up about a pivot point, causing the rocker member to shift the magnet to the opposite side of the base of the rocker assembly. This shift of the magnet changes the magnetic field to which the Hall Effect generator is exposed from one magnetic polarity to an opposite magnetic polarity which causes a respective change in output voltage of the Hall Effect generator from a first predetermined voltage to a second predetermined voltage. An audible 'snap' is generated by the magnet when it contacts the side of the base.

Solid state switch

A solid state keyboard comprised of a base module, a plurality of key members each having a plunger member comprised of a uniform mixture of a magnetic material such as barium ferrite and a binder such as nylon, and a respective plurality of improved Hall Effect generators, provides a significant improvement in performance and cost effectiveness. Actuation of a key member moves its plunger member, which has a preselected magnetic field, in rectilinear fashion relative to an improved Hall Effect generator, in which offset voltage has been substantially eliminated. This movement exposes the generator to a change in the direction of the magnetic field thus causing a corresponding change in the output voltage of the generator from a first predetermined voltage to a second predetermined voltage.

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Houston, TX, United States of America

Jon L Edwards