Patent GB-269784-A (GB)
Title: Course recorder for ships
IPC: G01C21/22
Filed: 1926-09-02
Abstract: 269,784. Baule, M. E. A. Sept. 2, 1926. Course-recording apparatus.-Means for recording the path of a ship comprises a map 3 disdisposed on a platform 2, a soft iron platform 7 adapted to be reciprocated, and a double electromagnet arranged between the platforms 2, 7 and comprising a constantly - energized winding 15 attracting a marking ball 17 movable over the map, and a winding 16 which is intermittently energized so as to be held to the platform 7 during the movements of the latter in one direction only. The platform 7 is mounted on rollers 8 on a table 5 carried by a pedestal 4 adapted to be rotated by gearing 9, 10 from a motor 11 operated from the ship's compass. Rollers 6, Fig. 2, are provided between the platform 7 and table 5 to ensure that these two members shall turn together in azimuth. Secured to the magnet 16 are four chains 19 - - 19<111> passing over guide pulleys 23 and around spring drums 20 - - 20<111>. Electromagnetic brakes 22 are provided for the drums, the brakes being energized while the winding 16 is inert, so as to retain the magnet 15, 16 stationary during the return movements of the platform 7. In a modified form of retaining- means, the platform 2 is of magnetic material and the magnet 15, 16 is provided with additional windings to act on the platform. In this form the armature of the winding 15 is provided at its upper end with a freely-disposed ball, to prevent sticking. The means shown in Fig. 6 for reciprocating the platform 7 comprises an intermittently energized electromagnet 36, the armature 35 of which is connected through a spring &c. 34 to a rod 31 connected through a bell-crank 29 to a rod passing through the pedestal 4 and connected at its upper end through a bell-crank 26 to a lug 25 on the platform 7. The amplitude of movement of the platform is adjusted according to the scale of the map and the speed of the ship, the rod 31 being for this purpose provided with a collar 37 moving between a fixed stop 38 and an adjustable stop consisting of a pivoted rod 39 the lower end of which, formed as a pointer 41 is adjustable along a screw 42 and moves over a cylinder 44 marked with generators representing map scales, and with curves for various speeds. The cylinder is turned until the appropriate generator lies under the pointer which is then displaced until it coincides with the appropriate speed curve. The modified means shown in Fig. 8 for actuating the platform 7 comprises an electric motor 54 connected through a clutch 55 operated by an electromagnet 56 to a shaft 57 which, through reduction gearing 58, operates a shaft 59 connected to the platform. The shaft 57 also drives, through multiplying gearing 60, a chain 61 carrying a member 62 which can move between a fixed stop 63 and an adjustable stop consisting of a carriage 64 which can be displaced along a screw 65 until a pointer 67 is at the appropriate point on a speed scale 68. On the carriage is a pivoted detent 69 adapted to be operated by an electromagnet 72 and controlling a pivoted arm 74 bearing a contact 76 co-operating with a contact 77 to control the circuit of the magnet 56. The member 62 carries an abutment 79 adapted, at the end of its travel, to move the arm 74 and break the circuit of the magnet 56 to disconnect the shaft 57 from the motor 54, the parts being then restored' to their initial position by springs 78 in the chain sprockets. The magnet 72 is then energized to release the detent 69 so that the circuit of the motor 54 is again made. The various intermittent circuits described are operated by a suitable rotary switch. Means may be provided for automatically changing over to an auxiliary battery when the supply current becomes too small. The platform 2 may be surrounded by conducting bands 101 with which the ball 17 contacts at the end of its permissible travel. For repeating the record at a distance, a repeater similar to the apparatus shown in Figs. 1 and 2 is provided, two or more of the chain drums on the repeater being operated synchronously with the corresponding drums 20 - - 20<111> by a suitable transmitter. The various switches &c., and if desired also the device shown in Fig. 8, may be mounted on a suitable switchboard separated from the recorder and connected thereto by wining and flexible shafts.