Patent GB-642775-A (GB)
Title: Tying machines
IPC: B65B27/06
Filed: 1948-01-06
Abstract: 642,775. Package tying-machines. BUNN CO., B. H. Jan. 6, 1948, No. 437. Convention date, Aug. 3, 1940. [Class 94 (i)] A tying machine comprises a package-supporting table, a knotting mechanism, a twine catcher below the table, a depending twine arm having a twine pay-out lower terminal normally disposed at package clearance distance above the table with the terminal reach of twine extending downwardly from the terminal through the table to anchorage on the catcher, means for mounting the twine arm and for moving its terminal through a verticallyelongated orbit about the catcher, means for actuating the twine arm moving means, and means for actuating the knotting mechanism in timed relationship to the movement of the twine arm for effecting actuation of the knotting mechanism while the terminal is near the bottom of its orbit so as to knot together the ends of a terminal reach of twine encircling a package on the table. The article 28 to be tied, is placed on a table 11 rigid with a main frame 10, rearwardly of a slot 12, Fig. 5. Twine 23 passes from a supply spool 22, Fig. 3 (not shown), through an adjustable tensioner (not shown), through a hole 25a in a mast 25, through a ring 26 in a needle arm 27, down a depending portion 27a of the arm 27, through a tubular offset 27b of the arm, through the slot 12 to the twine catcher 13. The arm 27 extends horizontally and perpendicular to the plane of Fig. 5, between the depending portion 27a and the top of a square crosssectioned post 49 with which it is rigid and which is slidably mounted in bearings 50 rigid with a carriage 51 itself slidably mounted for horizontal movement on rods 54, 55. The lower end of the post 49 is connected by a link 48 with the end of a lever 46 which is pivoted to the frame 10 at 47. A slot 45 in the lever 46 engages a pin 44 carried by an arm 42 pivoted at 43 to the frame 10 and carrying a roller 41 which is in engagement with a cam groove 40 carried by a gear wheel 32. An electric motor (not shown) drives the gear wheel 32 through a clutch 20, Fig. 3 (not shown), and a pinion 33. The gear wheel 32 has a lateral toothed 'extension the teeth of which are removed however between the points 38, 39 and 57, 61, Fig. 6. The teeth of this extension run in engagement with a pinion 31. The pinion 31 is connected eccentrically at 59 to a link 58 pivotally connected at its other end to the carriage 51. The pinion 31 carries two opposed pairs of rollers 37a, 37b which ride on an untoothed further lateral extension or rim 36 of the gear wheel 32. Part of the rim is removed at 36c, 36d to leave portions 36a, 36b. Operation. In tying an annular package, the latter is moved from the initial position (full lines, Fig. 7) to the position shown in dot-and-dash lines, thereby drawing out a bight in the twine between the terminal portion 27b of the arm 27 and the twine catcher 13. The operator then presses a pedal 21, Fig. 3 (not shown), which operates the clutch thereby causing the pinion to rotate until the gear wheel 32 has made one complete revolution (corresponding to a complete tying cycle) whereupon the clutch automatically (by means not shown) terminates the rotation until the pedal 21 is again pressed. At the commencement of the cycle the gear wheel 32 is in the position of Fig. 6 in which the rollers 37a riding on the rim 36a prevent rotation of the pinion 31. The roller 41 passes from the portion of the cam groove 40 at the centre of the gear wheel, to the portion near the periphery and this causes the post 49 and with it the arm portion 27b to be lowered through the slot 12 to a point below the twine catcher 13. When the rollers 37a pass off the rim 36a into the gap 36c, the toothed portion 39-57 engages the teeth of the pinion 31 which is rotated and thus causes the carriage 51 and arm portion 27b to travel to the position of Fig. 5. The leading tooth at 39 is strengthened by being of double width. A knotting head 15 (Fig. 2, not shown) is then actuated as described in Specification 449,019, and the twine is severed between the knot and the catcher by a cutter (not shown). During the knotting operation the arm portion 27b is held stationary since the rollers 37b engage the rim 36b and the roller 41 runs in the constant radius portion 40a of the cam groove 40, as shown in Fig. 5. At the end of the knotting operation the roller 41 reaches the end of the groove portion 40a and the arm portion 27b rises to its original height. At the end of this movement the rollers 37b run into the gap 36d and the pinion 31 rotates and so moves the arm portion 27b to its original position (Fig. 7). At this point the rollers 37a run into engagement with the rim 36a. There is a further small rotation terminating in the position of Fig. 6, in order to ensure that the rotation of the pinion 31 is completed and both rollers 37a are upon the rim section 36a. The twine now extends between the arm portion 27b and the catcher 13 through the centre of the annular package 28. The latter is then pushed further forwardly so that the inner surface of the diametrically opposite portion of the annulus forms a bight in the twine and the clutch operating pedal is actuated to form a second tie diametrically opposite to the first. The run of twine now lies outside the annulus. Specification 449,019, [Group XVII], is referred to.