Patent GB-598461-A (GB)
Title: Method of and apparatus for producing valved or sleeved bags
IPC: B31B19/84
Filed: 1945-09-05
Abstract: 598,461. Paper bags. ST. REGIS PAPER CO. Sept. 5, 1945, No. 22828. Convention date, Nov. 2, 1942. [Class 94 (ii)] Apparatus for forming a valve in a bag 20 and inserting a secondary sheet 36 lining to the valve comprises a clamp 32 to hold the edge of the gusseted bag prior to one end of the gusset being spread open by wings, spreader cups 33 opening the gusset to allow entry of the wings; and a separate shoe 35, carrying by suction means, the sheet 36, which has adhesive applied, is folded and thrust into the spread-open corner of the bag. As the shoe 35 withdraws a creasing plate 38 folds the valve and sheet 36, flat. Adhesive 124 is applied to one edge of the sheet 36, by a roller 123 and a wiper rotor 129 to secure the sheet inside the corner of the bag at the end of the operation. The bag 20 rests on a table 21 with its gusseted edge against a flange 22. The edge is gripped against a plate 40 by the clamp 32 which is moved forward by a slide 59 and sub-slide 60 ; after the latter abuts against a stop 69 a roller 68 engages a cam surface 67 forcing the clamp 32 down to grip the bag against the plate 40. Spreader cups 33 on rods 45, which may contain suction pipes 47, are brought to opposite sides of the bag gusset by link and cam action 51, 55 and gear sectors 49, to pull apart the gusset and allow insertion of spreader wings 34. The latter, carried by the slide 59 are rotated through 90 degrees on hinges 70 through arms 72 and a cam roller 74 and cam 76, to flatten out the corner of the bag ready to receive the sleeve sheet 36. Fig. 5 shows the mechanism for moving the shoe 35, carrying the sheet 36 towards the bag, and comprises a roller 101, on a crank 102, a gear 96 and racks 95, 97 which actuate a slide 94 on a table 93. The sheet 36 is held by suction, acling through holes 111. Paste is then applied to the edge of the sheet 36 through the roller 123 and wiper 129, a ratchet preventing reversal of the latter. A scraper 127 removes surplus paste. The sheet is then folded forwards by fingers 113, moved by a roller 119 through a cam. The folded-over portion 134 of the sheet extends as a cuff on the outside of the corner of the bag. Holders 37 are swung by a cam 141 against the rear bent-over portions 134 and press them against the outer portion of the bag which is in contact with shoe 35. The creasing plate 38, on a base 143, Fig. 1, actuated by links 144, 145, moves towards the bag and engages the central portion of the sleeve 36 as the shoe 35 commences to withdraw from the bag, suction through the holes 111 being relieved. As the plate 38 engages the sleeve, the holders 37 start to withdraw and the wings 34 start to close and flatten the corner and the slide 59 moves out, first withdrawing the wings 34 from the gusset and then releasing the clamp 32. The leading edge 133 of the sleeve extends into the bag and is held in contact with the latter by the strip of adhesive which was applied to the leading edge by the pasting mechanism. The valve is now ready for the insertion of a filling tube for example.