Patent GB-190720308-A (GB)
Title: New or Improved Apparatus for Automatically Preventing Collisions of Ships.
Inventor: ERDMANN GEORG
Filed: 1907-09-11
Granted: 1908-05-21
Abstract: 20,308. Erdmann, G. Sept. 11. Signals, electric. -Ships are provided with apparatus for transmitting and receiving electric waves, so that when two s h i p s approach e a c h other to within a certain distance, the waves transmitted from one ship act upon the receiving-apparatus of the other ship, thereby operating a relay device for stopping the engines. Rocks and islands may also be provided with electric wave apparatus for stopping approaching ships. This apparatus comprises an electric induction apparatus, the primary circuit containing a weak battery and a switch, and the secondary circuit a Righi oscillator. One form of apparatus carried by ships is shown in Fig. 3. The transmitting circuit consists of an induction apparatus a<2>, the primary circuit 1<1> of which contains a switch and weak battery and the secondary circuit 2<2> a Righi oscillator d<2>. This secondary circuit is connected to a rapidly rotating automatic switch t, to which is also connected the receiving-circuit 3<3> consisting of a coherer b<2>, battery, and electro-magnet g' in series. A lever h<2> forms an armature for the electro-magnet g<2>, and is provided with two contacts k<2>3, h<2>6, which, when the coherer is excited, complete circuits 4<2>, 6', respectively. The circuit 4<2> contains a powerful battery K' and a strong electromagnet P, which attracts an armature, to which is attached a lever p<2> operatively connected to the throttle valve of the engines. The circuit 6<2> contains a battery and electro-magnet X, which attracts an armature to engage with a stop V on the automatic switch, which is thus arrested with the transmitter circuit completed and the receiver circuit broken. The object of the automatic switch is to prevent the coherer from being rendered conductive by the radiations from the same ship, and it is so arranged that the transmitting and receiving circuits are never closed simultaneously. On the approach of two ships the radiations from one ship's transmitter will act upon the other ship's coherer, rendering it conductive, thus operating through the various electro-magnets to stop the engines ; also the automatic switches of both ships are locked so that the transmitters remain in action to prevent collision with other vessels. The switches in the primary circuits of the transmitting apparatus are closed by hand. Another form of apparatus which may be carried by a ship is similar to that above described, except that no automatic rotating switch is provided, the armature of the electro-magnet X operating to close the switch in the primary circuit of the transmitter apparatus, so that in this case the transmitter circuit is broken simultaneously with the stopping of the engines. A preferred form of the automatic switch is shown in Fig. 7. Upon a hollow shaft E of insulating material are fixed disks F, H of metal and disks G, I of insulating material, all of the disks being insulated from each other and being in contact at their circumferences with springs K, M, L, N, respectively. On the circumference of the disk I are fixed three segmental metal strips, insulated from each other and connected by wires to the metal disks F, H and to a segmental metal strip on the disk G. The contact springs K, L, M are connected respectively with terminals of the transmitter circuit, receiver circuit, and electrical tapping-apparatus acting on the coherer, the other terminals of these circuits being connected to the spring N. The segmental strips are so arranged that the circuits of the tapping-apparatus, receiver, and transmitter are closed in the order named. For additional security of insulation, the spring L connected to the receiver slides on the non-conductive surface of the disk G for a brief period before and after the transmitter circuit is closed. The switch is driven by means of the motor B through gear wheels C, D.