| 摘要 |
1,221,276. Trawling. FRIED. KRUPP G.m.b.H. 22 Oct., 1969 [23 Oct., 1968], No. 51830/69. Heading A1A. An apparatus to determine the disposition of a trawl net comprises an inclination measuring device 10 for determining the inclinations of the net relative to two mutually perpendicular horizontals, which device is secured close to the mouth of the net on a base-plate on the bottom rope 12 or on the head-rope 9 (as shown), a device to transmit the inclination information over a cable 11, and an indicating device 25 to receive the information of the trawler. The instrument 10, Fig. 4, comprises two mutually perpendicular spindles 13, 14 carrying pendulums 15, 16 mounted within a water-tight container 17 filled with oil for damping and provided with a pressure-equalisation diaphragm 18. The spindles are connected to variable electrical components 20, 21 which alter the frequency of the oscillators 22, 23 in proportion to the displacement of the two pendulums 15, 16 respectively. The oscillator output signals modulate the output oscillation of the transmitting generator 24, for example one signal may be amplitude modulated, the other frequency modulated. The multiplexed signals may be separated by filter networks of known kind and indicated on the trawler. |
