Patent GB-1434944-A (GB)
Title: Method and apparatus for recording the number of phenomena
IPC: G07C3/14
Filed: 1973-03-28
Abstract: 1434944 Recording apparatus; testing insulation; measuring displacement electrically B ZUMBACH [trading as ZUMBACH ELECTRONICAUTOMATIC] 28 March 1973 [10 April 1972] 14894/73 Headings G1J G1N and G1U The number of events, e.g. wire insulation faults, vehicles passing, occurring in a recording period are recorded on a record tape or sheet 2 in a direction transverse to the direction of advance of the tape, a stylus 10 being moved in said transverse direction a number of equal-sized steps equal to the number of events. The tape 2 may be advanced one step at the end of each recording period, or may advance continuously. The stylus is reset to a zero position at the end of each period. Preferably the tape 2 is of pressure-sensitive paper. In Figs. 1-9, a multi-channel recorder for recording insulation faults in enamelled or varnished wires has a respective stylus 10 for each of a set of test pulleys, Fig. 8 over which wires under test are passed. Each stylus 10 is formed by the free end of one arm of a generally U-shaped spring steel member secured at its base to a beam 11, the bent-down end 12 of the other arm engaging the first arm and also a face cam 15 on a cam disc 14 freely rotatable on a shaft 21. Each cam disc 14 has peripheral ratchet teeth engaged by a stop pawl 16 and by a driving pawl 17 on a striker spring 18 which is lifted and released by a solenoid 20 each time a fault is detected in the wire under test. This rotates the disc 14 one step, and moves the stylus 10 one step across the tape 2. A gap in the ratchet teeth prevents the disc 14 from being advanced more than one revolution. Pins 22 on the shaft 21 can engage internal lugs 23 on the discs 14 so that all the discs can be reset to a zero position by a single rotation of the shaft 21. Each test pulley Figs. 8 and 9 comprises insulated shoulders 38, 39 on the outer race of a ball bearing 37, the inner race of which is carried on a pin 36. A test voltage, e.g. 1000V, from a source 56 is applied to the bearing 37 over which the wire 45 under test is passed. The shoulder 39 carried a disc 41 having raised segments facing a fixed similar disc 42 to form a variable capacitance which provides a pulsating signal when the pulley rotates. Recording tape and stylus zeroing drive Figs. 4, 5 and 9. The recording period corresponds to the passage of 100 metres of wire 45, an odometer (not shown) closing a switch 48 for every 10 metres to emit a pulse to a counter 49 and a NAND gate 50. The counter 49 triggers a pulse generator 51 after receiving 10 pulses, to actuate a relay 52 energizing a motor 27 which rotates for one revolution, its shaft 26 carrying a cam 28 which actuates a holding switch 31, a lifting beam 19 to raise the styli from the tape 2, and a stop 32 for the cam-shaft 21, the stop being released so that the shaft is rotated to reset the cam discs 14 to zero. The shaft 21 also carries a cam 8 which on rotation actuates a ratchet mechanism, Fig. 5 to advance the tape drum 3 one step while the styli are raised. Stylus control circuit Fig. 9. On passage of a fault over a test pulley, a Schmitt trigger 59 is reversed and a pulse is applied to the solenoid 20 via an amplifier 60, advancing its cam 14 one step. Normally the pulsating signal from discs 41, 42 of the pulley acts, via a limiting circuit 61, amplifier 63, and rectifier 64 to maintain a Schmitt trigger 66 in a state in which it blocks the NAND gate 50, and hence the pulses due to the odometer. On failure of the test voltage, jamming of the test pulley, or no wire 45 passing, the Schmitt trigger 66 clears the gate 50 so that regular pulses from the odometer pass to the solenoid 20, the resulting regular traces of less than full height indicating a fault in that test channel. A modification, Fig. 10, has each stylus 10 moved stepwise by a linear cam 73 having an inclined cam surface (82), Fig. 11 (not shown) and advanced by a linear ratchet mechanism. At the end of a test period, a solenoid 80 is energized, causing a beam 79 to move springs 77 to disengage the drive and stop pawls 17, 16 from the ratchet 72 to allow the cam 73 to return to zero position by gravity. The tape 2 passes between the styli 10 and a viewing window 70. In other applications, the recording periods may be predetermined periods of time.