Patent GB-190925365-A (GB)
Title: Improvements in Apparatus for Operating Ships' Rudders by Electricity.
IPC: G05D1/02
Filed: 1909-11-03
Granted: 1910-11-03
Abstract: 25,365. Marks, E. C. R., [Soc. Anon. Italiana G. Ansaldo, Armstrong & Co.]. Nov. 3. Systems for controlling travel for a fixed distance or number of revolutions. - In an arrangment for electrically operating ships' rudders by means of a dynamo and a motor, the torque of the operating-motor increases with the speed of the ship, the angle through which the rudder is turned, and the angle through which the steering-wheel is turned, by causing these conditions to act upon the excitation of the motor and the dynamo. Arrangements are also made for decreasing the torque of the motor when the rudder is moving from its operative to its middle position, and a spare motor is employed to replace the operating- motor in the case of a breakdown. A motor M<2>, driven from the ship's mains, is coupled to a dynamo G<2> arranged under normal conditions to supply the operating-motor M<1> of the rudder, when the commutator switch i is in the position shown. The motor M<1> is connected to the rudder post T through a clutch I<2>, shaft A, and gearing. The movement of the rudder operates a regulating-switch D, having a resistance d<1> in the field circuit of the motor M', and a resistance d<2> in the field circuit of the generator G<2>. In addition to the resistance d<2>, the generator field g<2> has in its circuit a regulating-switch B, the resistance of which varies with the speed of the ship; and a regulating and reversing switch P, of which the resistance p<1> varies with the angle through which the steering-wheel R is turned. The shaft T is provided with an electro-magnetic brake F having two operating-coils f<2>, f<1>, the former rendering the brake operative and the latter rendering it inoperative. In the case of a breakdown of the motor M<1>, the rudder may be operated through a clutch I<1> by running the two machines M<2>, G<2> in series as motors from one of the generators G', G, the fields of which are controlled in the same manner as the field of the generator G<2>, by placing the commutator switch i in its middle position. If the motorgenerator set M<2>, G<2> fails, the motor M<1> is supplied from one of the generators G<1>, G<0> by placing the commutator switch i in its extreme left position, and the switch j in one of its operative positions. Switches K<1>, K<2> break the circuit of the generator winding g<2> when the rudder is in either of its extreme positions; while the rudder may be operated from any other prime mover through gearing V<3>. The operation of the arrangement is as follows: - When the lever p of the switch P is in the position shown, the circuit of the hold-on coil f<2> of the brake F is completed as follows: terminals a, 2, W, X, bridging-contact of lever p, contact k, terminal 4, winding f<2> and terminals y, s. When the lever p is moved through an angle a by means of shaft a<2> and gearing c<2>, which may be replaced by an electric power-transmission arrangement, the circuit of the winding f<2> is broken at the contact k, and the circuit of the release coil f<1> completed from the points z, terminal 5, winding f<1>, and terminals y, s. The circuit of the generator winding g<2> is simultaneously closed as follows: - Terminal a, contact 2 of switch P, contacts c, e, terminal 3, commutator bar f, terminal g, fieldwinding g<2>, terminal h, commutator bar f<3>, regulating-switch B, terminal 2 and resistance d<2> of switch D, terminal 1, switch K<2>, terminal 9, resistance p', terminal 1, brush m, and terminal 6 of switch P, and terminals 4, 3 of switch D to terminal s. The generator G<2> then supplies current to the motor M' to operate the rudder and a plate carrying the contacts of the switch P through gearing C<1> and a shaft a' until the angle a is reduced to zero and the circuit of the generator field g<2> broken. When the rudder is moving from an operative position to its inoperative position, the inner resistance replaces the outer resistance of the switch P by the action of the lever d of the switch D, in order that the potential applied to the motor M' may be lower when the motor works at practically no load. The direction of rotation of the motor M<1> is controlled bv the direction of the current in the field winding g<2> of the dynamo G<2>, which is reversed by means of the switch P,