Patent GB-1250256-A (GB)
IPC: G01D9/28
Filed: 1969-09-25
Abstract: 1,250,256. Recording apparatus. LEEDS & NORTHRUP CO. Sept. 25, 1969 [Sept. 30, 1968], No. 47331/69. Headings G1J and G1U. In a recorder system using a potentiometric measuring arrangement the capacity of a multipoint recorder, capable of recording a fixed number of points, is increased by grouping the inputs to be measured and their associated input relays into banks, the relays of each bank being operated in sequence via a bank selector switch and a point selector switch cyclically operated in synchronizm with the chart marking means for recording points for each input to the bank and an identification point for that bank. The number of input relays per bank equals the point recording capacity of the recorder. On energizing the recorder, print motor 50 drives print wheel 60 to bring each number on the wheel e.g. 1-12 and its associated mark one after another into position for printing on the recorder chart. If more than twelve points per bank are used then the wheel 60 can be tilted to print additionally 13-24. The motor also drives in synchronizm with the print wheel a 12-position rotary point selector switch 70 via which and the wafer B of bank stepping switch 110 the input relays of the selected bank, e.g. K1, B1 &c., are energized. Where a 24 point system is used switch 60B is operated during alternate revolutions of rotary switch 70 and energizes relay KP so that transfer switch 90 changes over and via a selector switch 80 the rotary selector switch energizes relays 13-24 of the selected bank. With the system set to continuous log CL by switch 17 relay K1 is energized and with relay K2 picked up the slow chart speed motor 405 is energized. Assuming the bank stepping switch 110 is set to bank 1 and the rotary selector 70 to point 1 then relay K1B1 is picked up via contact 1 wafer B of the stepping switch and via its contacts prepares the measuring circuit 20 to receive the inputs associated with bank 1. In addition via contact 1 of transfer switch 90 and contact 1 wafer C of switch 110, relay K2 is short circuited to switch the chart speed momentarily to fast. Additionally relay KE2 is energized to shunt slide wire 69 of the potentiometric measuring circuit with a parallel resistance path R1, R2 to produce a signal which drives slide wire contact 1% along its length and this via coupling 71 positions indication print wheel 60 at about 1% of its scale across the chart. At this time the print wheel is moved towards the chart to read a 1 indicating that the readings following are of bank 1. The print motor now drives the print wheel and the selector switch on to its 2nd position in which contact 2 of the transfer switch is now energized thereby releasing relay KE2 removing the short circuit from relay R2 so that the recorder now goes back to slow speed and picking up relay K2B1 so that the input signal associated with the relay is applied to the measuring circuit and its magnitude measured and recorded as the wheel prints 2. In succession the remaining input relays of bank 1 are picked up and their associated inputs measured and recorded substantially in line (because of the slow speed) across the recorder chart. When the selector switch 90 reaches its last e.g. 24th position relay K3 is picked up and energizes the coil A255 of stepping switch 110 so that the second bank is now selected, and the inputs to the second bank measured and recorded.  Lamps are provided to indicate which point of which bank is connected to the recorder. Bank switches 100 are provided whereby the bank associated with a closed switch is omitted during the logging process and means are provided for rapidly advancing from one bank to another. The system includes a sensing circuit 86 which in response to deviation of an input above or below a set value can produce an output when the system is set to 'log an alarm' by switch 17 to initiate logging of the signals. In this arrangement the system continues working but relay K1 is deenergized to operate print hold out solenoid PHO. When the sensing circuit operates relay K1 is picked up and logging recommences. The arrangement can also be switches to log on demand or to log a single input.