Patent GB-741622-A (GB)
Title: Improvements in or relating to telemetering systems and apparatus
IPC: G01F23/44
Filed: 1953-05-27
Abstract: 741,622. Selective signalling. JURS, A. E., sen., YOUNG, R. M., JURS, E. E., JURS, P. C., and JURS, A. E., jun., [trading as SHAND & JURS C.]. May 27, 1953, No. 14803/53. Class 40(1) A telemetering transmitter for sending impulses in accordance with the displacement of, for example, the float of a water level indicator as described for example in Specification 741,181, comprises a member movable in accordance with the value of the quantity to be signalled and a second member geared to motor-driven impulse springs, the arrangement being such that impulses are sent out during the period taken by the second member to travel from an arbitrary starting position to a particular position in relation to the first member. In one of the two systems described, the transmitter is organized to send over a two wire line an identifying train followed by trains representing feet and inches respectively. In the other, there is no identifying train and the feet and inches trains are sent simultaneously over separate circuits. Transmitter construction-nrst arrangement: A float-driven shaft 11 is geared to a disc 28 which carries a contact 49 and registers inches. Once per revolution, this disc gives a partial rotation to a pinion 33 driving a disc 27 which carries a contact 44 and registers feet. When a signal is to be sent, a motor is energized and by means of the gear train shown at the left of Fig. 1 and in Fig. 2 drives (a) impulse springs S6, (b) an arm 151 the position of which can be adjusted so as to determine the number of impulses to be sent out in an identifying code, (c) a cam disc 87 controlling contact springs S1 which co-operate with a group of relays to ensure a proper sequence of operations, (d) a cam disc 128 which actuates off-normal springs S2 and controls a latch for preventing the rotation of pinion 33 and consequently of the "foot" register disc during the transmission of a reading and (e) a contact arm 56 co-operating with contacts 43, 48 displaced in accordance with the water level &c. and so controlling the number of impulses sent in accordance with the feet and inches of the level. Means may also be provided for locking the "inch" disc. Circuit operations, Fig. 14 feet and inches signals sent in succession. The reception of a starting pulse over lines Tl, T2 energizes R1 which connects transformer 157 and motor 69 to the power line L1, L2 and energizes R4 which locks up and energizes R2. R3. R1 thereupon falls back but R2 is held over off-normal contact t and R3, R4 remain locked up and the transformer and motor remain energized over off-normal contacts r. After a short interval, nose 102 of spring-set S1 drops into a notch 92 in cam 87 unlocking R4 which connects the impulse springs S6 to line. Identifying pulses are thus sent out until the adjustable arm 151 reaches contact q whereupon R4 comes up again, breaks the impulse circuit and locks up. After the period allotted for transmitting the identifying signal, springs S1 change over again to release R4, which again connects impulsing springs to line. Impulses are transmitted until the arm 56 engages contact 43, the position of which depends on the "feet" figure of the water level. R4 is then re-operated and locks and the impulse springs are disconnected. When disc 87 has nearly reached its starting point springs S1 operate again to unlock R4. This time R3 also is unlocked, there being no alternative holding circuit over contact S3. On the relapse of R4 impulses are again sent to line and this continues until arm 56 encounters contact 48, the position of which indicates the "inches" figure of the reading. R4 is then energized again to stop the transmission. When 87 again nearly reaches its home position, off-normal springs S2 are restored to release R2 which disconnects the power supply and the. apparatus stops in its normal position. Modified system, Figs. 15-17 (not shown), Two signalling circuits are provided by two individual lines and a common return. In response to the starting impulse over one circuit, the motor starts to drive the impulse-springs and control-cams. After a pre-determined time, the operation of a relay starts the transmission of impulses over both signalling circuits and these are stopped by separate relays energized when the arm 56 reaches the "feet" and "inches" contacts respectively.