Patent GB-346659-A (GB)
Title: Improvements in electric signalling devices for ships
IPC: B63H21/22
Filed: 1929-12-14
Abstract: 346,659. Revolution direction indicators. GRAHAM & CO., Ltd., A. and VAUGHAN, C. H., St. Andrew's Works, Slough. Dec. 14, 1929, No. 38314. [Class 106 (iii).] Comprises electric signalling apparatus for a ship in which an indicator board is provided with two series of apertures which emit red and green light respectively to denote rudder angle and further apertures to indicate direction of rotation of the engines. In the example shown in Fig. 1 suitable for a ship having twin screws, the indicator board A forms part of a box B fixed to the forward bulkhead of the bridge. The apertures a, b in the shape of arrows are illuminated with red light to indicate rotation of the port engine ahead and astern. Similar openings a<1>, b<1> are illuminated by green light for the starboard engine. Two additional apertures c, c<1> in the shape of propellers are constantly illuminated by red and green light respectively to emphasize the starboard and port signals. A line d in the shape of a boat is also marked on the board. Above and below the arrows are two series of apertures e, f which are illuminated red and green to indicate turning of the rudder to port or starboard, the number of apertures illuminated giving the degree of turning. The last apertures e<1>, #<1> are made larger or of different shape in order to indicate " hard over" position, while an aperture g is illuminated with yellow light to indicate central position of the rudder. Two such boards may be used located at an angle to the centre line of the ship and may be hinged to the box so that this inclination may be varied. The apertures are preferably covered with coloured transparencies illuminated from behind by an electric lamp. Fig. 7 shows the circuits. Contacts i<1>, j<1> are carried by arms k, k<1> of a lever mounted on a pivot k<3>. Spring-controlled fingers n, n<1> are pivoted to the ends of the arms and are engaged by a cam projection o carried by a band clamped to the shaft. On the shaft rotating in the direction indicated by the arrow, the finger n will be engaged and the lever k, k<1> rocked to open circuit j, j<1> and close the circuit i, i<1> of the lamp h behind the aperture a. At successive rotations of the shaft in the same direction, the finger n<1> will be engaged and rocked idly by the cam o. On reversal of the shaft, the switch is thrown over and the lamp behind the aperture a<1> is lit. Springs k<9> are provided to give a snap action to the switch. To give a flicker to the light, spring contacts r, r<1> are provided in a box t carried by one arm of a lever u the other of which carries the armature w of an electromagnet x. When the latter is excited by closing a switch y, the lever is moved so that the part s is in the path of the cam o and the contact r, r<1> is made and broken at every revolution of the shaft. When the flicker is undesirable, the switch y is opened and the spring v holds the contacts out of the path of the cam. These switch arrangements are duplicated when there are two engines. The switch controlling the lamps behind apertures e, el, f, #<1> and g comprises segments 1 .. 7, 1a .. 7a of different length fixed to a baseplate. Between segments 1, 1a, 2, 2a are sheet-metal insulated segments 9, 9a. The segments 1 .. 7, and 1a .. 7a are connected to lamps behind apertures e, e<1>, f, #<1> by conductors 10, 11 while segments 9, 9a are connected by a conductor 12 to the lamp behind aperture g. To the base is also fixed a metal contact-ring 13 connected by a conductor 14 to the negative 15a of the supply source. The positive 15 is connected to the lamps h through resistances 16 and a common conductor 16a and switch y. A metal bar 18 insulated from its spindle is rotated over the segments from the ship's rudder. The bar carries spring balls 21 .. 27 and in mid position the contacts 21, 22 bear against the central segments 9, 9a. Contacts 28 constantly bear on the ring 13. A rotary switch 34 serves for cutting in and out the resistances 16. The lamps for apertures c, c<1> connect to conductor 14 through the hand switch 35 and also one terminal of each magnet is connected to the conductor 14, the other being connected to a lead 36 also connected to the flicker switches r, r<1>. When two boards are used the lamps are connected in parallel or series for simultaneous operation.