Patent GB-324422-A (GB)
Title: Automatic wireless distress signal and position indicator
IPC: H04L15/22
Filed: 1929-03-08
Abstract: 324,422. Cuthbert, J. G., (Richardson, N.). March 8, 1929. Morse and like code signal-transmitting arrangements; selective signalling-apparatus. - In an automatic signalling-apparatus for sending emergency signals from ships, of the type in which a rotatable drum 9, Fig. 1, carries a plurality of code signals formed as conducting portions on sections of the drum, brushes 1b - - 12b bearing on the signal portions of the drum are connected by conductors 1a - - 12a, to a selector switch. The odd brushes are connected to the contacts 1c - - 11c of a switch arm 11, Fig. 1a, and the even brushes to the contacts 2c - - 12c of switch arm 10, the brushes related to one switch being on one side of the drum, and those relating to the other being on the opposite side, white the signal portions of the drum are confined to one half of its periphery. Alternatively all the brushes may be on one side of the drum, and the signal sections alternately on opposite halves of the periphery. The drum 9 is driven by a motor 10m, from a source of power p connected through a rheostat 4, and two brushes 5c, 3d bearing on a ring 5 geared to the motor shaft, the brushes being short-circuited momentarily by a push-button 6 when it is desired to start the motor. The ring 5 has a portion 5b of insulating material upon which the brushes 5c, 5d rest when the motor is stationary but upon starting the motor, as above, the brushes become short-circuited by the conducting portion 5a of the ring until it has performed one revolution and the brushes again engage the portion 5b when the motor stops. During this time the selected signals are transmitted by the ship's wireless installation which is "keyed" by a relay 7, in circuit with the power supply p, the selected drum segments, the switch arms 10, 11, and the return lead X. In an emergency, for example in case of collision, fire, or flooding, the motor may be arranged to run indefinitely, by mounting a disc 13d, Fig. 3, on the motor shaft, carrying a peg 5d which supports a switch-arm 9d when the motor is stationary. On starting the motor as above, the arm 9d is released and the plug 15d is forced into the socket 16d by the spring 12d short-circuiting the starting switch. On subsequent revolutions of disc 13d the peg 5d passes through a recess 19d formed in the switch-arm 9d, and does not actuate the latter. In the case of collision, a switch I, Fig. 5, held open by threads 7e, 8e and a heavy mass 6e, is closed by the breaking of the threads due to the inertia of the mass 6e and starts the motor, as above. Similarly a switch II, Fig. 5, held open by a rod 15e of fusible metal is closed by the melting of the latter due to fire, while flooding operates switch III, Fig. 5, by causing the swelling of loose cellulose 25e packed into a telescoping container 21e, 22e and normally held together by a thread 24e. In an emergency system set in operation as above, the selector switch which may have three rotary arms 4k, 4m, 4n, Fig. 6, is provided with a locking device operated by the momentary current passing through the starting device which may be a push-button or either of those shown in Fig. 5. This current energizes an electromagnet 2r, Fig. 6a, which through the armature 20r and the catch 19e releases a rod 14f carrying a cross-piece 14e with three. projections 7f, 8f, 9f, which are propelled by a spring 18e into engagement with three star wheels 7e, 8e, 9e (see also Fig. 6) carried by the shafts e1, e2, e3 of the selector switch thereby clamping the latter and providing a common electrical connection with the rest of the circuit. In moving into this position, a knob 17e carried by the rod 14f passes over a spring catch 30e, preventing the movement of the clamping bar by turning either of the switch arms. The device may be reset only by the release of the catch 30e. The switch shafts e1, e2, e3 carry control handles h1, h2, h3, and indicating dials 6e, while projecting arms 11e, 13e may be provided to engage the star wheels 8e and 9e respectively, to advance them one contact for every complete nevolution of the wheels 7e and 8e respectively. Additional wiper arms 50e, 51e, Figs. 9, 10, insulated from but attached to two of the switch shafts and working over contacts 50k, 51k may be set to indicate the ships position on a chart, and, by a prearranged code, simultaneously to set the selector portion of the switch to signal the ship's position. Thus the two shaft extrensions may be connected by springs 50f and leads 54, 56 to a battery 52, and leads from the two sets of ten contacts taken to one hundred lamps 50c as shown so that any one oi the lamps may be lit. The lamps may be arranged under a chart (Figs. 7 and 8 not shown) and an additional switch may be provided in the battery circuit.