Patent GB-190600180-A (GB)
Title: Improvements in and relating to Electrical Signalling Systems.
Filed: 1906-01-02
Granted: 1907-01-02
Abstract: 180. British Thomson-Houston Co., [General Electric Co.]. Jan. 2. Signals, time-alarm, indicator or visible, electric-lamp, and bell. -Relates to a system of signalling, particularly adapted for use on board ship. On large ships in which there may be several furnace rooms with several furnaces in each room, the system described enables the time for firing each-furnace to be signalled from the engine-room. A transmitter having a time mechanism, with means permitting of adjusting the timeinterval, is provided at the sending station, which operates several receivers, each of which is capable of giving a plurality of different indications. Referring to Fig. 1, which represents the transmitter, a clock mechanism 10 is mounted on a support 9, the seconds hand shaft of which carries three contacts 11. As the shaft rotates, the contacts 11 engage a stationary contact 12, closing a circuit every twenty'seconds which includes an electro-magnet 13 with an armature 14 held by a spring 15. The armature 14 has a shoulder 14<1>, and carries a pivoted pawl 16 held by a spring 17 in engagement with the ratchet-wheel 18 which is secured to a sleeve loose on a shaft rotating in bearings attached to the support 9. A spiral spring 21 turns the ratchet-wheel 18 when released, until it is arrested by an arm 22 attached thereto engaging with the frame, while a pawl 24 is held against the ratchet-wheel by a spring 24<1>. The arm 22 carries a contact which engages with an adjustable contact 25, carried by an arm 26 secured to the shaft 26<1>, when the ratchet-wheel 18 is turned. The shaft 26<1> carries an indicator 29<1>, and may be rotated by a worm-wheel 27 and worm 27<1> carried by shaft 28. Contacts 22, 25 control a signalling circuit, and the circuit of electromagnet 30, which when energized raises pawls 16, 24 permitting the spring to rotate the ratchetwheel 21. The arm 32 is L-shaped so that the shoulder 14<1> on the armature 14 holds the arm 32 and pawls 16, 24 until the magnet 13 is again energized. The brush 37 of the commutating switch 30 is electrically connected to the shaft 36, but the brush 38 is insulated therefrom and crossconnects the segments 34 and ring 35. When the magnet 30 attracts its armature, the arm 40 'is turned until the pawl 41 engages the next tooth, and when the magnet is de-energized the ratchetwheel and brushes are rotated. By means of plugs any of the segmental contacts A .... F of the switch may be connected to the contact 46, and contacts a ... f are each connected to one segmental contact. The receiver is shown in Fig. 3. When the magnet 48 attracts its armature, the leaf-spring 50 cross-connects contacts 51, 51<1>, and the spring- controlled latch 52 turns on its pivot so as to bring its shoulder under the end of the arm 49, thus holding the switch closed. When the armature 54 of the electro-magnet 53, which is connected to a pivotally-mounted dash-pot 55, is attracted, its outer end engages the latch 52, thus opening the switch. A small synchronous motor controls the indicating devices and comprises three electromagnets 58, 59, 60 secured to an iron plate and symmetrically arranged about a shaft pivoted therein. The shaft carries an electro-magnet with segmental portions 64, 65 connected to a cylindrical core. As the magnet rotates, the segmental portions pass in close proximity to the cores of magnets 58, 59, 60. The shaft also carries an indicator and insulated rings to which the coil is connected, and brushes bear on the rings and conduct current tu and from the coil. A lamp 70 connected across the brushes illuminates the dial, and conducting strips 1<1>, 2<1>, 3<1> are connected to the coils of magnets 58, 59, 60, these coils being also connected together. The electrical connexions of the apparatus are shown in Fig. 5, provision for six receivers being made. The terminals of each receiver are connected to the mains 77, 78, and those of the transmitter to the mains 75, 76. In operation, the contact 25 is moved to the desired position by turning the wheel 28<1>, and a plug is inserted between contact 46 and the contact corresponding to the receiving instrument to be operated, the contact A being shown so connected. If the clock mechanism is in operation, the contacts 11 engage contact 12 at intervals of twenty seconds, closing a circuit from main 75, through terminal 6, contacts 11, 12, electro-magnet 13 and terminal 7 to the main 76, thus energizing magnet 13 which attracts its armature 14 and draws back the pawl 16. On breaking circuit, the pawl 16 moves the ratchet-wheel 18 a distance equal to one tooth. This recurs until the contact 22 engages the contact 25, closing a circuit from terminal 6, through contacts 22, 25, and electro-magnet 30 to terminal 7 and also from contact 25 through terminal 4<11>, wire 4, strip 4<1>, electro-magnet 48, terminal 71, wire a<1>, terminal a, contact A, and contact 46 to terminal 7. The electro-magnet 48 attracts its armature, bridging the contacts 51, 51<1> by the spring 50, closing circuits from the terminal 72, through lamp 86, contacts 51<1>, 51, to the terminal 73, and also from the terminal 72, through magnet 53, contacts 51<1>, 51, and terminal 73. After a short interval, owing to the retarding influence of the dash-pot, the armature of magnet 53 causes the latch 52 to release the switch arm 49, which, pulled by the spring 49<1>, breaks the circuits. The electromagnet 30 being also energized, as above described, turns the pawls 16, 24 till they are out of engagement with the ratchet-wheel, in which position they are held by the latch 14<1>, and the ratchetwheel 18 is then turned by the spring 21 until the arm 22 engages the frame 20. When the electromagnet 30 is energized, the rod 45 is moved down, and the pawl 41 engages the next tooth. When the contacts 22, 25 are separated, the armature 31 is retracted by a spring 33, raising the rod 45 and turning the wheel 39 and brushes 37, 38 through a distance equal to one tooth, and half a segment, respectively. This changes the connexions to the coils of the synchronous motor, moving the indicator to a new position, in the following way :- As shown in Fig. 1, the brush 37 bears on the segments 80, 81, Fig. 5, of the switch, and the brush 38 connects the segment 82 and ring 35, closing circuits from terminal 6 through the shaft 36, brush 37, segments 80, 81, terminal 1<11>, wire 1, strip 1<1>, electro-magnet 58, and from segments 80, 83, terminal 3<11>, wire 3, strip 3<1>, to the coil of magnet 60. From coils 58, 60, the circuits join, passing through the coil 59, strip 2<1>, wire 2, terminal 2<11>, segments 84, 82, brush 38, and ring 35, to terminal 7. The coil 63 is also energized, and rotates to a position in which the segmental portion 64 is midway between the cores 58, 60, as shown in Fig. 3. When brushes 37, 38 are turned through a distance equal to one half segment, the current through the coil of magnet 60 is reversed, again turning the electro-magnet 63 and indicator one-sixth of a revolution. The next movement of the switch reverses the current in the coil 59, and again rotates the armature an equal amount. The indications may be given in other ways, as by closing lamp circuits, or if desired a bell in the circuit of lamps 86 may be rung.