GB807411A - Apparatus for control and adjustment of stabilising fins and rudders of water craft - Google Patents

Abstract

807,411. Stabilizing and manoeuvring ships. McNAB, N. S. Oct. 16, 1956 [April 10, 1956], No. 10904/56. Classes 113 and 114. [Also in Group XXIX]. Apparatus for controlling stabilizing fins, for retarding pitch or roll, or rudders comprises a hydraulic unit or units, e.g. hydralic units 18, pivotally connected to a flanged bush 16 arranged to transmit rotary movement to a stock 2, controlled by a rotary valve 24 having a control valve member 28 concentrically disposed within a sleeve member 27. The sleeve member is connected by a link 42 to the bush 16 to follow the angular adjustment of the stock to cut off and lock the pressure fluid within the hydraulic cylinder 18. The control lever 40 of the control valve member 28 may be regulated manually or in the case of stabilizing fins may be gyroscopically controlled in which case the lever 40 is connected by a link 41 to a disc 43 mounted on a shaft 44 intermittently rotated by a motor 47 through a ship clutch 45. A member 48 having two teeth 180 degrees apart is mounted on the shaft 44 and the teeth engage a pawl 49 mounted on member 50 adjustable concentrically with the shaft 44. The roll-responsive gyroscope precesses at the commencement of roll and moves the pivoted switch lever 52 to engage one arm of U-shaped member 55 to complete the electrical circuit and energise the solenoid 51 which releases the pawl 49 to permit half rotation of the shaft 44 and angular adjustment of the lever 40 to adjust the fin 1. After the initial electrical contact has been made the insulated end 56 of the lever 52 moves the U-shaped member 55 and breaks the electrical contact until the precessing movement of the gyroscope effects movement of the lever in the opposite direction to complete the circuit through the other arm of the U-shaped member. The time period of the fin movement is regulated to less than the time period of roll of the vessel. Two valves 24 as shown in Fig. 4 for adjustment of port and starboard stabilising fins may be provided, and the fins may be withdrawn into a housing in the hull by hydraulic units.