GB517166A - Improvements in or relating to apparatus for controlling ship stabilising installations - Google Patents

Abstract

517,166. Automaticcontrol systems ; stabilizing ships. SIEMENS APPARATE UND MASCHINEN GES. Aug. 23, 1938, No. 24828. Convention date, Aug. 23, 1937. [Class 38 (iv), [Also in Groups XXXIII and XXXVIII] An arrangement for controlling ship stabilizing installations in accordance with the angle of list or roll of the vessel and if desired in accordance with the angular list velocity comprises a follow-up motor 1 having a large inertia and connected across two contact arms 13, 15, associated with a potentiometer 5, arm 13 being driven by the motor 1 and arm 15 by an angleof-roll indicator 7. The control dependent on the list angle is obtained from a rotary magnet 21 connected between the centre of the potentiometer 20 and an associated contact member 18, 19, operated by the motor 1. Further control in accordance with the angular list velocity may be obtained from a rotary magnet 22 connected across the contact arms 13, 15 and an additional controlling rotary magnet 25 may be provided energized in accordance with the angle of roll from a potentiometer 24 having its contact arm 23 operated by the indicator 7. The three rotary magnets may be replaced by a common rotary magnet. The potentiometers may be supplied with alternating current, the tapped-off voltages being supplied to primary windings of a transformer having a single secondary winding from which the composite control potential is obtained. Control of the tank stabilizing installation may be effected by controlling the angle of incidence of the propeller of a pump employed therein, the action of the rotary magnet being increased by a power amplifier and servomotor. In a modified arrangement. Fig. 4, two potentiometers 40, 41 having contact members 44, 45 operated through screwed spindles 51, 52 by an angle-ofroll indicator 48 are provided with further contact members 46, 47 operated by follow-up motors 42, 43 the damping of which can be varied electrically or mechanically and which are connected respectively across contact members 44, 46 and contact members 45, 47. The motor 42 also drives a contact arm 56 and has small inertia while motor 43, which has a large inertia, also drives a disc 58 carrying contacts with which the arm 56 co-operates to control electromagnets which control the stabilizing apparatus. The spindle 52 may be arranged to be driven rather more rapidly than the spindle 51 so that in addition to control of rolling, static list is also compensated for. The invention may be used for preventing pitching of a vessel. Specification 389,553, [Group XXXIII], is referred to.