Patent GB-346272-A (GB)
Title: Improvements in and relating to method of and means for adjusting a contactor according to the indications of a sensitive indicator
IPC: G05D1/02
Filed: 1929-12-21
Abstract: 346,272. Mariners' compasses and wind vanes. HOLMES, B. B., Stonington, Connecticut, U.S.A. Dec. 21, 1929, No. 39180. [Classes 97 (ii) and 97 (iii).] A sensitive indicating instrument such as a compass, wind vane or pressure gauge is used to control apparatus or its indications are repeated at a distant point and there is provided a second element serving as an electric contactor which is guided in a path adjacent and similar to that of the primary indicator element, the second element being arrested in its movements periodically whilst free to position itself during the intervals between arrest. In the case of a compass for controlling a steering gear, the second element follows the compass needle except when shifted axially away therefrom. Two long and two short tubes 26 carrying the needles of a compass are supported on a float 25 and conical pin 22 in the usual manner and preferably a further needle 31 is supported at the top close to the glass cover 18. A frame 35 is supported in a circumferential groove 32 on the compass and may be oriented thereon. The frame 35 has a shoulder 36 carrying an annular ring 37 of insulating material on which are mounted contacts 53, 54, 55 and above it is a glass top 39 which at the centre carries a solenoid 45 and centrally therein is a pin 48 on which are two needles 51, 52 with their poles oppositely disposed but the needles 51 being nearer the compass magnets results in the system following the magnets when the pin 48 and needle system are in their lowest position and the resilient extensions 58 of the needle 51 are away from the contacts. On the solenoid becoming energized, the needle system is drawn up, the contactor 58 engages one of the contacts 53, 54, 55, the contactor 59 engages a dead contact, and the system is held fixed so that it is arrested from following the rotary movement of the compass magnets. A series of conical studs 57 are mounted between the contacts for guiding the contactor into definite engagement with only one contact. An electric motor 66 drives the shaft 67 at reduced speed, and a further reduction gear 71, 72 drives the commutator 73 with which coact the brushes 74 in the battery circuit 116 of the solenoid for periodically energizing it and arresting the needle system. The shaft 67 drives two bevel wheels 81s, 81p which are freely mounted on a shaft 82 geared to the steering worm 98. Each gear carries an annulus of soft iron 86 whereby the magnetic clutches 87 mounted on plates 88 fixed on the shaft 82 may transmit the drive according as to whether starboard or port helm is required. The shaft 95 of the worm 98 carries an adjustable commutator drum 99 which is made up of two conducting areas of copper 102, 103 with an insulating strip between them. Brushes 106 coact with the commutator and are wired to the contacts, and according to the operative contact the worm 98 will remain stationary or turn to port or starboard. For heavy weather control, the centre contacts are disconnected and the brushes wired to the outer set of contacts by means of a number of double-pole single-blade switches 114, 115. In a modification, the needles when the solenoid is de-energized drop on to conical heads which serve to re-align them with respect to the compass.