PREVENTER Russian patent published in 2004 - IPC

FIELD: oil and gas extractive industry.

SUBSTANCE: device has cylindrical body with upper and lower flanges, vertical pass aperture and cylindrical horizontal hollow being in perpendicular intersection with the latter, in which hollow a locking element is mounted with possible rotation, which element includes a compactor of elastic material and ring-shaped cylinder. In groove of ring cylinder screw-thread dies and covers with compactions are mounted without possible rotation. In walls of ring-shaped cylinder a through aperture is made, axis of which coincides with axis of vertical pass aperture. Compactor of elastic material is mounted on outer surface of ring-shaped cylinder and consists of two ring-shaped compactions, placed in ring-shaped recesses, made on outer surface of ring-shaped cylinder, evenly spaced from through aperture, and of four compactions, made in form of straight lengths, connected to ring-shaped compactions and mounted in grooves on forming lines of ring-shaped cylinder at 90° distance and evenly spaced from through aperture. Mechanism for manual displacement of screw-thread dies includes threaded rod, nut, cover with compactions and control wheel. Nut is mounted in the cover with possible rotation and is fixedly connected to the control wheel. On outer surface of ring-shaped cylinder a corbel is mounted with guiding aperture. Axis of guiding aperture is parallel to axis of horizontal hollow of body. In guiding aperture a finger is mounted with possible longitudinal displacement between two fixed positions, interacting in front position to fixedly mounted two stopping bushings on outer surface of body, and in back position - with the control wheel. Central angle between two stopping bushings equals 90°. One of stopping bushings interacts with a finger in position of coincidence of through aperture of ring-shaped cylinder and vertical pass aperture of body, and second stopping bushing interacts with finger after rotation of ring-shaped cylinder for 90°.

EFFECT: simplified construction and higher reliability of operation, lesser maintenance, operation, mounting and dismounting costs.

4 dwg