GB225929A - Improvements in and relating to leader gear cable systems and apparatus - Google Patents

Abstract

225,929. Seymour, C., Wilkinson, A., and Atherton, J. F. Sept. 11, 1923. Leader gear.-A leader gear system is adapted to give a visual indication which shows whether a ship is erring to port or starboard of the leader cable. The port coil P and starboard coil S are connected in turn to the input terminals of an amplifier A by a cylindrical rotary distributor R driven by a motor M. The output terminals of the amplifier are connected through a rectifier C to a galvanometer B by distributor segments R<3> so arranged that the current through the galvanometer is intermittently reversed in synchronism with the interchange of the connections of coils P and S. Thus current flows intermittently through the galvanometer B in one direction or ihe other according as coil P or coil S is excited, and the needle takes up a mean position depending on the relative degrees of excitation. In a modification, the distributor R may be replaced by a set of eight spring switches operated by a set of four cams mounted on a common shaft. Each cam D, Fig. 3, may be of insulating material such as red fibre, or of insulated metal, and the corresponding spring 1 may be provided with :a metal roller E or with an insulating pad. Each cam is so designed that the switch 1, 1<1> is closed for slightly more than half a revolution, so that coils P and S are momentarily connected in parallel and the indicator B is momentarily shortcircuited to avoid opening the output circuit of the amplifier; or there may be a time lag between the switching operations in the output and input circuits. It is stated that with the above arrangement a deflection is obtained which rises to a maximum at a short distance, from the cable, drops to zero immediately over the cable, then changes direction and reaches a maximum again at a short distance on the other side.