Patent GB-281707-A (GB)
Title: Improvements in or relating to signalling the position of moving bodies
IPC: G08B3/10
Filed: 1927-12-02
Abstract: 281,707. Soc. Industrietle des ProcÚdÚs W. A. Loth. Dec. 2. 1926, [Convention date]. Tell-tale apparatus.-In a method of signalling the position of compass cards, particularly for signalling the course of one ship to another, in which the card is' periodically immobilized by lifting it from its pivot, a circuit is closed for a definite time when the card is lifted and again after an interval of time depending on the position of the card. The circuit is closed by a rotating arm directly or indirectly through a contact carried by the card. The arrangement is such that the time interval between the two currents is never less than, say, one second, small compass readings being specially provided for. In the arrangement shown in Figs. 1 and 2, the compass card 3 carries a member 3<1> having a conducting sector which is movable into the path of a rotating brush 27. The card normally rests with its pivot 2 on a support 13 surrounded by a sleeve 15 which is raised periodically by a cam 18, so that its upper end engages a spherical cap 14 on the float 12 and immobilizes the card. A surface 22 controlled by a cam 24 then raises the float as a whole until the member 3<1> engages the seating 25, thus bringing the conducting sector in the member 3<1> into the path of the brush 27. The spindle 29<1> carrying the brush 27 is driven by clockwork at a constant speed, and is' geared to spindles 31, 30, provided with contact discs 40, 42 engaged by brushes which together with the brush 27 are connected to relays controlling a signal transmitter 50, as shown in Fig. 2. The speed of the spindles 29', 30, 31 and the arrangement of the brushes is such that at the commencement of a cycle the circuit of the transmitter 50 is closed for four seconds, say, by a relay 46 which is energized over contact I of disc 40 and brushes 41, 43, and after an interval determined by the position of the card is again closed for one second, say, by a relay 54 connected to brush 27. In order to ensure that this interval is never less than one second, a contact II on the disc 40 is connected to a relay 51, the armature of which is mechanically interlocked with the armature of a magnet 57 in series with the brush 27, the arrangement being such that if the brush 27 engages the sector 4 before the contact II on disc 40 engages brush 41 (i.e. less than a second after the contact I on the disc 40 leaves brush 41), the armature of relay 51 holds open the circuit of the transmitter until the next rotation of the brush 27. The clockwork is driven from an exterior shaft 39 through a fluid-tight connection by means of a bent shaft 33, the end of which is journaled in a bearing 35 locked in a cage 36 which is connected to the compass bowl in a liquid-tight manner by resilient caps 37. The initial and final signals may be given by different transmitters. In the modification shown in Fig. 4, the compass card 3 is periodically raised by the cam-operated sleeve 15 and a radial contact 4 on the float 12 is caused to engage one of 360 wires, such as 61, connected to contacts 63 engaged by a rotating contact 27, which thus closes a circuit at a point in a cycle determined by the position of the card. This impulse and an initial impulse cause a time switch to close the circuit of the transmitter for a period of one second. The Specification as open to inspection under Sect. 91 (3) (a) also describes the following arrangements. (1) In the modification shown in Fig. 11 (Cancelled), the indication of the position of the card is effected in two steps, a plate 84 being first caused to take up a position corresponding to the card, and the position of this plate being then signalled. As in the previous arrangements described, the card 3 is periodically raised by a cam-operated sleeve 15, and a radial contact on the member 3<1> is brought into the path of a brush 27, which is' rotated by gears 65, 66, cranks 67, and links 68, 69, 73 by clockwork in synchranism with a disc 27', which is normally coupled to a disc 83 and drives the plate 84. When the brush 27 engages the contact on the member 3', a magnet 83 disconnects the parts 27', 83, which are retained in the position shown in Fig. 11 (Cancelled) by the engagement of catch 80 behind the sleeve 81, the plate 84 remaining in a position corresponding to that of the card. A cam 85 then releases a chronometer 87, the hand of which closes a circuit through a radial conductor on the plate 84 at a point in the cycle determined by the position of the plate 84, and therefore of the card. (2) The circuit between two rotating brushes may be closed by a conducting sector 4, Fig. 4 (Cancelled), in the compass card, or by a projection carried thereby. Instead of rotating, a brush may periodically move radially over one of several series of code contacts, such as 40, Fig. 3 (Cancelled), arranged radially on the compass-card. (3) The compass card may be always free, light or other rays being used with a photo-electric cell &c. In the arrangement shown in Fig. 1 (Cancelled), a lamp 5 and a photo-electric cell 6 are rotated at constant speed on opposite sides of the compass card 3 having a radial slot 4, the time interval between the release of the arm 7 carrying the lamp and the influencing of the cell depending on the position of the card. In modifications, the card may be transparent with an opaque sector, or may carry a mirror, or a fixed torus-shaped lamp may be used, the photo-electric cell only being moved. Instead of light, ultra-violet or infrared rays or electromagnetic waves may be used. This subject-matter does not appear in the Specification as accepted.