GB577193A

GB577193A - Improvements in and relating to magnetic transmission

Info

Publication number: GB577193A
Application number: GB3033/44A
Authority: GB
Original assignee: British Thomson Houston Co Ltd
Current assignee: British Thomson Houston Co Ltd
Priority date: 1943-02-23
Filing date: 1944-02-18
Publication date: 1946-05-08

Abstract

5 77, 19 3. Indicating liquid-levels. BRITISH THOMSON-HOUSTON CO., Ltd. Feb. 18, 1944, No. 3033. Convention date, Feb. 23, 1943. [Class 123 (i)] [Also in Groups XIX and XXXV] The shaft 13 carrying the pointer 12 of a liquid level gauge is mounted on a smooth cylindrical shaft 16 which is magnetized with its poles across a diameter, the axis of the poles being spiralled along the shaft as at 17. If the tank varies in cross-section, the pitch of the spiral varies accordingly. The shaft 16 is surrounded, by a non-magnetic tube 18 on which a float 19 is constrained to move vertically only, by a guide rib 21. The float carries a circular permanent magnet 23 with poles 24, so that as the float moves with changes of liquid level, the shaft 16 and pointer 12 rotate. The tube 18 is sealed to exclude the liquid. In a modification, Fig. 2 (not shown), the float is guided by projecting diametral pins moving in a vertical slot in a surrounding tube, and the rotation of the shaft is transmitted to the pointer through a sealing diaphragm, by a magnetic coupling. In other modifications, Figs. 4 and 5 (not shown), the float carries two pairs of poles and moves over a pair of parallel magnetized shafts, the spiral of one of which has ten times the pitch of the other so that unit and tens pointers of a gauge can be driven.. In Fig. 6, a spirally-magnetized shaft 49 is rotated by a magnetic gear-wheel 50 having a number of horseshoe magnets 51 with projecting poles arranged around the periphery, which engages with the shaft in the manner of a worm gearing. A rod 35, Fig. 7, may be spirally magnetized by attaching it to a non- magnetic holder 55 and drawing it between the poles 52, 53 of an electromagnet while it is rotated by the engagement of a set-screw 56 in a spiral groove 57. The rod is drawn into a shield 54 of magnetic material to prevent demagnetization by leakage flux from the electromagnet. Specifications 535,168 and 549,590, [both in Group II], are referred to.