Patent GB-715112-A (GB)
Title: Improvements in and relating to marking buoys
Inventor: CHRISTIE JAMES PETER
IPC: A01K75/04
Filed: 1950-01-02
Abstract: 715,112. Radio signalling; radio reflectors and beacons; valve circuits. VENNER ELECTRONICS, Ltd. April 2, 1951 [Jan. 2, 1950], No. 18/50. Classes: 40 (5), 46 (6) and 40 (7) A marker buoy particularly intended to mark the position of fishing gear, is fitted with a radio transmitter and a time switch arranged to connect the power supply means to the transmitter after the lapse of a pre-set period of time, and subsequently to render keying means operative for short periods separated by predetermined intervals, the keying means causing an identifying signal to be repeatedly emitted. The mast carrying the aerial may also be fitted with a flashing lamp, and a corner reflector for facilitating location by radar apparatus on the fishing boat. The buoy, Fig. 1, comprises a watertight casing 1 with removable cover 2 and inspection lid 4, mast 5, lamp and lens 7, and a support 9a for a corner reflector and an aerial. An accumulator 18 is housed in a recess in the concrete ballast 16, above which is resiliently mounted a frame 15 carrying a rotary converter 17, a radio transmitter 11 and a clockwork time switch 19. This switch, shown in Fig. 5, comprises a graduated dial arranged, in the example described, to rotate once in twenty-four hours and a pre-set switch arm 38 which after a predetermined time closes a main switch 39, Fig. 7. The clockwork includes an arbor 40 rotating once in forty minutes and carrying two parallel cam discs 41 each having four rises, operating switches 43, 46, the switch 43 being in the heater circuit of the valve cathodes and the switch 46 serving to start up the converter for supplying high tension to the valves. The rises are so placed that the heater circuit closes before high tension is applied, and that bothcircuits are opened simultaneously after the radio transmitter has operated for one minute. An interval of nine minutes is followed by further closures of the switches 43, 46. Referring to the circuit diagram, Fig. 7, and assuming the main switch 38, 39 has closed, the closing of clock switch 43 completes a circuit from the battery 18 through the valve heaters connected at 47, 48. The subsequent closing of the switch 46 energizes a relay 33 which closes its contact 35 and starts up the converter 20 for supplying high-tension current. The converter shaft is geared down to three cams 24, 27, 30. The first cam 24 serves to make and break the lamp circuit 8. The second cam 27 rotates at about four times per minute and controls a contact 28 in parallel with the contact 46 of the clock switch. Opening of the contact 28 by the rise 27a has no affect for the first three revolutions, but the fourth opening finds the contact 46 already open with the result that the relay 33 is de-energized, the converter 20 stops, and the radio transmission ceases. The third cam 30 is on the same shaft as the cam 27 and its rim is so shaped that each rotation sends out the identifying signal by keying the radio transmitter at the contact 31. The main switch 38, 39 remains closed until opened by the personnel on the fishing boat after recovery of the buoy. The speeds of rotation and the periods of operation mentioned above are by way of example.