Patent GB-758335-A (GB)
Title: Improvements in torpedoes
IPC: F41G7/22
Filed: 1946-02-14
Abstract: 758,335. Photo electric control system. WALL, V. C. Feb. 14, 1946, No. 4690/46. Class 40 (3). [Also in Group XXI] A torpedo is provided with means, such as a photo-electric cell, which are responsive to bubble formation in a ship's wake and which, when so responding bring into operation auxiliary control apparatus alternative to the normal steering control. The arrangement is such that the torpedo, when wake responding, is made to turn successively in alternate directions so that it proceeds in or about the wake on a substantially zig-zag or serpentine course. Wake-responsive means.-In one construction, Fig. 4, use is made of the pressure change which occurs when the bubble formation is encountered. A housing 68 is attached to the nose 70 of a torpedo and is surrounded by a member 71 which is attached to a cylinder 72 and also to the torpedo. Within the cylinder is a ball 73 attached to a valve 74. In normal conditions the valve abuts against a stop 75 due to water pressure on the ball, and in this position air from a supply line 76 passes through a choke 80 into a chamber 81 from which air gradually escapes by way of passages 84, 85 until the pressure in chamber 81 balances that on the ball. When the torpedo enters a ship's wake an increased pressure acts on the ball causing it to drag the valve 74 forwards. This movement uncovers the exhaust channel 85 and also allows air to pass via the route 82, 87, 88 behind a valve 83 causing the latter to move and thus to allow air to pass via the route 82, 89, 90 and choke tube 93 into the chamber 81 until the original condition is restored. The fluctuation of internal air pressure occurring within the apparatus during such movements is utilized to control the auxiliary steering mechanism as described below. In a modification, the wake is detected by the reflection of light by the bubbles in the wake. Thus, as shown in Fig. 5, 139 is the light source, 132 is a window near the front of the torpedo, and 133 a photo-electric cell upon which the light is reflected, the cathode 134 of the cell being in circuit with an amplifier 135, and relay 136 which latter operates a valve or switch in the steering control circuit. In another modification the refraction of light caused by the bubbles is employed. Auxiliary steering control gear.-Referring to Fig. 6, pressure air passes through a pipe 141 to a gyroscope rotary valve 143 in known manner, and thence to valve mechanism 111 to operate a steering engine 113. When the torpedo is fired a " safe-range " valve 132 automatically opens after the torpedo has travelled a predetermined distance and pressure air then enters leads 78, 79 of which the latter leads to the detecting apparatus. When air pressure builds up in leads 78, 79, a piston 103 is forced against spring pressure to rotate a plate 106 through a distance corresponding to one tooth of a ratchet 108. When detection takes place the pressure in leads 78, 79 falls as described above and springs 104, 105, operate to rotate plate 106 which is connected to a rotary valve 110 having several supply and exhaust ports. Rotation of the valve serves to supply air to one or the other of leads 163, 165, according to the pre-setting of plate 109, and to exhaust the other, these leads being connected to the steering engine valve gear and by reason of their large cross sectional area enabling the pressure air therein to take over the steering control. The torpedo thereby changes course until it once again passes through the wake, when the rudder will be moved in the opposite direction and so on.