Patent GB-778615-A (GB)
Title: Strip feeding arrangement
Inventor: FORD GEOFFREY EWART
IPC: B65H20/04
Filed: 1954-09-29
Abstract: 778,615. Automatic registration control. FORDS (FINSBURY), Ltd. Sept. 22, 1955 [Sept. 29, 1954], No. 28099/54. Class 38 (4). [Also in Groups XVI and XL (b)] In an apparatus for forming bottle caps from metal foil bearing a repetitive pattern of marks, the strip feed is actuated through an oscillated lever connected at a point spaced from its pivot to a connecting rod which actuates the means for feeding the strip, a detector being provided to detect discrepancies in register in the forming of caps from the printed cap areas on the foil, the detector controlling the feed so as to correct such discrepancies by effecting an adjustment of the distance between the point of connection of the connecting rod to the lever and the lever pivot to vary the length of feed produced by a stroke of the lever. As shown, aluminium foil 2, Fig. 2, is fed intermittently to a blanking tool (not shown) by rollers 5 driven by a pinion 6. The pinion 6 is driven through a free-wheel by a disc 7 oscillated by a connecting rod 8 connected to a slide 9. The slide 9 is attached to an arm 10 oscillated about a pivot 11, the arm being oscillated by a connecting rod 12 driven by a crank pin 13 on a disc 14 driven in synchronism with the blanking tool. The slide 9 is movable towards and away from the pivot 11 on a rod 15, carried by the arm 10, by a link 16 pivoted to the slide 9 and to a control lever 17 that can swing about a pivot 18. When the control lever is in its neutral position, the slide 9 is at the centre of the rod 15 and the axis of the pivot connecting the lever 17 and link 16 coincides with the axis of the pivot 11. By raising the left-hand end of the lever 17 upwardly the slide 9 is moved further away from the pivot 11 thus increasing the length of feed effected by the rollers 5. The lever 17 is retained in its neutral position by a roller 19 engaging in a V-notch 20 on a spring-urged arm 21. During feeding the lever 17 is raised or lowered automatically should the foil be out of register with the blanking tool by a double-armed cam 24 driven at half the speed of the disc 14. The cam lobes engage fingers 26, 27 pivoted to the lover at 28, 29. The armatures of relays 30, 31 on the lever 17 respectively engage the fingers 28, 29 and arrest their turning, thus causing the lever 17 to be rocked upwards and downwards to vary the length of strip fed. A cam 34, driven at the same speed as the disc 14, actuates a central contact 35 normally engaging a contact 36, such that it engages a contact 37. The contacts 36, 37, Fig. 5, are connected to the grids 39, 40 of thyratrons 41, 42 in a control circuit which includes the relays 30, 31. If the strip is correctly registered an impulse from a photo-electric cell 48, which detects the repetitive pattern on the strip, occurs at the same time as the contact 35 is disengaged from the contacts 36, 37 and neither thyratron will fire. However, should the strip be out of register the contact 35 will be engaged with either the contact 36 or 37 at this time; thus the appropriate thyratron 41 or 42 will be fired to actuate a relay 44 or 45 respectively. The thyratron that is fired is subsequently extinguished by opening a switch 38 in its anode circuit by the cam 34. Impulses are generated by the photo-electric cell 48 when marks on the strip are beneath a lamp 49, light from which is reflected by the strip on to the photo-electric cell 48. The strip feed may be adjusted manually by providing the pivot 18, Fig. 2, on a plate 51 pivoted to the frame and carrying a pointer 54 which cooperates with a scale 55, the setting of the pointer being adjustable by loosening a screw forming the pivot 18 to permit appropriate movement of the plate 51. A pointer 64 pivoted at 65 to the frame and at 66 to the lever 17 carries a cursor 68. The cursor 68 moves up or down a scale 69 during movement of the lover 17 thus giving a visual indication of the corrections that are being applied to the feed. Predominant movement in one direction indicates the need to adjust manually the setting of the plate 51 to decrease or increase the length of feed. Correct register of foil from a new spool can be quickly achieved by operation of a switch 71, Fig. 5, which energizes relay 30 independently of the automatic energization by the thyratron 41, thus reducing foil wastage before register is achieved. In a modification, the pivot 18, Fig. 2, may be raised or lowered slightly, to vary the length of feed, through reduction gearing driving a screw. Specification 756,440, [Group XVI], is referred to.