Patent GB-190604422-A (GB)
Title: Improvements in Electro-mechanical Devices for Producing Corresponding Positions in Transmitting and Receiving Apparatus.
Inventor: BARR ARCHIBALD
Filed: 1906-02-23
Granted: 1907-02-21
Abstract: 4422. Barr, A., and Stroud, W. Feb. 23. Water and other liquid levels, regulating &c.-Relates to apparatus for communicating orders,alarms, notifications, ranges, an g u l ar observations, and helm or engine signals, or for indicating the level of water in reservoirs, &c. The transmitter consists of a device for commutating a current so as to cause the magnets of the receiving-instruments to be energized in the required order. The receiving- instrument has three or more separate armatures a, b, c, Fig. 2, mounted upon the same axis but so situated with respect to the electro-magnet fields A, B, C that the fields can only act on the corresponding armatures. For this purpose, the armatures are spaced apart on one spindle, and the electro-magnets so arranged as to impart to the armature a step-by-step motion when energized. Either the armatures or the magnets may be regularly disposed about the axis. Multipolar armatures may be used, and the poles of the electro-magnets spaced accordingly. For instance, if three-armed armatures are used, the two polepieces of each electro-magnet would be arranged at 120 degrees apart instead of being opposite each other. An electro-mechanical catch comes into operation wl en the current is broken to hold the indicating-mechanism at the last transmitted indication. As alternatives, the current is either broken automatically or considerably reduced in strength at the transmitter when the handle is not being worked, and made or brought full on when the handle is forced forwards or backwards. In order to hold the armature more stable when the current is off, a spring may be adapted to engage a notched wheel or disk. Friction, liquid, or other control devices such as a fly are used to prevent the operator from moving the contact-maker too rapidly. Fig. 3 illustrates six positions of the spindle e in rotting through 180 degrees when three armatures are angularly .disposed at 120 degrees according as the electro-magnets A, A and B, B, B and C, C, C and A are energized. Fig. 8 illustrates the application to a range indicator. The armature spindle e drives the apindle g carrying the drum h marked with 00, 25, 50, 75 three, times, and driving in turn the hundreds' drum k and 'similar drums l, m, thus giving ranges from up to 19975. The commutator for the transmitter may consist of a contact-piece E<1>, Fig. 10, with strips B<3>, C<3>, &c. arranged on a glass drum. The current is brought in through the brush E<2> and distributed to the brushes A<4>, B<4>, C<4> leading to the electro-magnets. These contactpieces may be in the form of a receiver which is.in close proximity to the transmitter and which itself controls receivers at the distant station. The electro-magnetic catch r, Fig. 17, consists of an arm on an armature q attracted by any one of the three electro-magnets, and engaging the wheel s attached to the armature spindle or some part of it ; it is thus only released when no current passes through any electro-magnet.