GB1151506A - Apparatus for Controlling a Work Performing Device such as Flying Shear - Google Patents

Abstract

1,151,506. Controlling flying shears. ENGLISH ELECTRIC CO. Ltd. 12 Aug., 1966 [13 Aug., 1965], No.34862/65. Heading B3W. An apparatus for controlling a flying shear 2 comprises a detecting means 3 to detect the arrival of the leading edge of the work material 1 at position A and for initiating operation of the flying shear 2 before the material reaches the position C, the said operation activating a trigger 7 to start a calibration count by a counter 11 of the distance BC, and a second counter 16 for progressively counting the passage of predetermined lengths of material past the position A. The stock material 1 is advanced towards the shears 2 and reaches the position A where the photocell 3 detects it and applies a continuous output to the AND circuit 4 and the trigger 5. A pulse generator is associated with each mill stand S7-S10, one of which is connected through the switch 15 to the AND circuit 4. The output from the trigger 5 is fed to the gating circuit 7 and to the OR circuit 6, whereupon the shear 2 is accelerated to effect a " calibration cut." The count in a gating circuit 21, preselected by an operator by means of the knobs 22 through gear-box 23 and binary digitizer 24 is simultaneously fed to the counter 16. The limit switch 8 is momentarily closed to apply a pulse through the gate 7 to the trigger 9, and the AND circuit 13 and consequently a progressively increasing count is entered into the counter 11 from the pulse generator associated with the mill stand S8. As the material 1 is fed past the position A, the count in the counter 16 is progressively decreased and an increasing count entered into the counter 11. When the leading edge of the material reaches position C, a continuous signal is applied to the gate 10 from a photo-cell 19 resulting in a stopping of the count of the counter 11, i.e. " the calibration count " equivalent to the distance BC. The count in the counter 16 continues to decrease as the strip passes between the shear until it reaches zero, whereupon a continuous pulse is applied to the AND circuit 17, the NOT circuit 18 and the OR circuit 12 to the AND circuit 13 resulting in the count of the counter 11 being progressively decreased to zero whereupon a continuous output is applied through the AND circuit 17 to the OR circuit 6 to cause the shear 2 to accelerate and cut the material. The signal which initiates this cut is also fed through the trigger 20 to the gate 21 and the preselected count is again entered in the counter 16. The counter 11 is thereafter held at zero since both photo-cells 3, 19 are continuously activated. The cut length setting is determined by the operator on manual movement of the knob 22 and the switch 15 is ganged to the switch 26 so that the indicator 31 gives a correct reading for the various diameter rolls in the mills S7-S8.