Patent GB-1406818-A (GB)
Title: Monitoring of machine operation
IPC: D04B35/10
Filed: 1972-09-22
Abstract: 1406818 Measuring rate of use of yarn C R CRABTREE 22 Sept 1972 [29 Sept 1971] 43983/72 Heading G1A [Also in Division D1] The length of elongated input material e.g. yarn used during selected cycles of a machine e.g. a knitting machine is monitored by first means detecting each cycle of operation and emitting a pulse in response thereto, second means for measuring the length of input material being fed to the machine and registering it, the pulses from the first means actuating control means which actuate the second means to prevent it during a predetermined number of cycles from measuring while continuing to register the visual read-out and resetting it before the next selected cycle. A yoke 33 carried on the machine frame comprises a plastics or metal housing and carries in one branch a photo-transistor to receive light from a light emitting diode 31 or incandescent lamp in the other branch. This light is interrupted once per rotation of the needle cylinder by an opaque body 36 carried on the take-up roller. A housing 41 containing course counter 48 carries the display dial for this and also contains power unit 40 e.g. a battery pack. Counter 48 may be preset to stop the machine after a certain number of courses. Yarn being fed to the machine is metered by a wheel 52 driven by it. Pulses are produced by light passing from a diode 73 through one or more openings 57 in the wheel to a phototransistor 74 and are fed to a Schmitt trigger 44 and thence through control means 90 to a decade counter 75 with two inputs, the other being connected through a reset drive 94 to control means 90. The output from counter 75 is decoded and displayed on read-out display member 77 e.g. a light emitting diode display panel control 90. Wheel 52 and control means 90 are in a hand held unit 100 with member 77 visible through display window 81. Wheel 52 is carried in a housing 58 which comprises circular section telescoping portions 59, 66. Each portion has in its circular part 60, 67 a lug 64, 71 with a bore 63, 70 forming journal bearings for a steel or like shaft 55 embedded in the moulded plastic body of wheel 52 which has a high friction surface 54 e.g. formed by attaching an abrasive coating thereto. Bore 63 is also a lubrication inlet. Aligned openings 62, 69 correspond in position to the openings 57 in wheel 52 and overlying access openings 65, 72 for yarn are provided in the sides. Approximately one quandrant of housing 58 is received in housing 78, openings 62, 69 being aligned between diode 73 and photo-transistor 74. Pulses from yoke 30 are fed to course counting unit 45 and via Schmitt trigger 42 and cable 82 to Schmitt trigger 43. Pulses from yarn metering unit 51 pass to Schmitt trigger 44 which emits signals corresponding to units of length of yarn 14. Each signal from Schmitt trigger 43 changes the state of flip-flop 91 so this normally occurs once per rotation of the needle cylinder. In the first position flip-flop 91 actuates gate 93 and the latter responds to signals from Schmitt trigger 44 and this produces the read-out of the length of yarn used in one rotation of the needle cylinder. At the end of the rotation, the next pulse alters flip-flop 91 and activates gate 92 so that during the next rotation (or more if a delay is introduced e.g. before Schmitt trigger 42) the reading is held. The next signal to Schmitt trigger 43 passes through gate 92 to reset drive 94 which resets the counter read-out of zero. At the same time flip-flop 91 is returned to the first state and the pulses from Schmitt trigger 44 once again pass to counter 75. With a stationary cylinder knitting machine, the yarn can be metered through a telemetry link.