Subsurface well working equipment comprising the combination of a tubing string and a tool

摘要

907,530. Magnetic switches. CAMCO Inc. Aug. 20, 1959 [Dec. 8, 1958; March 30, 1959], No. 28470/59. Class 38 (5). [Also in Group XXI] Series connected magnetic switches for operation at preselected positions of a movable member within a tube, such as a tool within a well, include spaced annular permanent magnets each having non-magnetic spacers on each side. As shown, annular permanent magnets 2, 3 are located between respective pairs of non-magnetic annular spacers 2a, 3a and are radially magnetized so that the flux is carried by the magnetic tube 1, and magnetic distance pieces 4, 5 and passes in the tube around the spacers. The movable tool carrier 13 has soft iron discs 33, 34 spaced to align with the spacers 2a, 3a and complete the magnetic circuits of both magnets 2, 3. An extension 35 of the disc 34 passes above a pivotally mounted D'Arsonval movement coil 19, 20 so that when both discs 33, 34 are magnetized contacts carried by the coil are operated, but if only one disc is magnetized the coil is urged to its inoperative position.