Patent GB-1381871-A (GB)
Title: Machine for closing filled bags
IPC: B65B51/06
Filed: 1971-06-16
Abstract: 1381871 A machine for closing filled bags THURNE ENG CO Ltd 12 Sept 1972 [16 June 1971] 28273/71 Heading B8C A machine 10 for closing filled bags comprises a guide 17, 18, Fig. 2, which, in use, receives the open end part of a filled bag as it is moved through the machine, a stop 22, 23 which is movable between a retracted position and an advanced position in which it extends into the path of the open end part of the bag as this moves along the guide, a follow-up member 21 which is movable along the guide following a bag to compress the end part of the bag against the stop with the latter in its advanced position, the stop then moving to its retracted position as the compressed end part of the bag is moved by the follow-up member 21 further along the guide, means for supplying a length of adhesive strip 30 and holding it across the path of the compressed end part of the bag as this moves further along the guide, and means 49, 50 for clamping the length of adhesive strip around the compressed end part of the bag to hold the bag closed, the clamping means subsequently releasing the closed end part of the bag to allow it to be moved out of the guide. The bag-tying machine 10 is mounted at one side of an endless conveyer 12, Fig. 1, so that the open ends of a series of filled bags placed on the conveyer successively move into the machine between the pair of parallel guide bars 17, 18 assisted by conveyer belts 19, 20 which move in synchronism with the conveyer 12, the reciproeable follow-up member 21, moving at a greater speed than the belts 19, 21 to push the neck of the bag up against co-operating detents 28, 29 in the pair of pivotally-mounted, stop blades 22, 23. The latter are urged by springs 26, 27 into their stop positions across the path 14 so that the neck of the bag is compressed between the follow-up member 21 and the stop blades 22, 23. As the follow-up member 21 continues to move forward the blades 22, 23 pivot against the action of the springs 26, 27, Fig. 4, so that the recesses 28, 29 surround the compressed bag end, at the same time an adhesive strip 34, with a series of spaced strips of paper 30 adhered to one of its sides, is pulled down across the path 14 by the arms 39, 40 of a gripper mechanism 40, which is reciprocable transversely of the path 14, in to adhesive contact with one side of the compressed neck of the bag. At this point a knife 37 severs the adhesive strip 34 in the middle of a corresponding applied paper strip 30, the arms 41, 42 of the clamping mechanism 49, 50 are moved, by respective parallogram linkages 43, 45 and 44, 46, in a direction towards the neck of the bag and parallel to the guide bars 17, 18, and the arms 39, 40 of the clamping mechanism 38 open to release the end of the strip 34 as the mechanism 40 is retracted. The arms 41, 42 move apart against the action of springs 47, 48 as they approach the bag neck to move around the severed strip 34 and clamp it around the neck of the bag, the ends of the strip each carrying a strip of paper to facilitate the subsequent opening of the bag. The arms 41, 42 are then retracted to pull the bag neck in the forward direction the blades 22, 23 pivoting further against the springs 26, 27 to release the bag neck as it is pulled out of the machine by the arms 41, 42, the blades 22, 23 springing back on to their blocking position, and the backing member being lowered and moved back to the mouth of the path 14 ready to pick up the next bag. Lengths of paper strip are cut from a strip 30 by a knife 33 and are applied at intervals to the adhesive side of the strip 34 as the latter passes over a former beneath the knife 33. An adjustable curb 13 on conveyer 12 positions the series of bags on the belt 12 so that the open ends of the bags enter the mouth of the machine 10. In a modification, Fig. 6, not shown, the blades 22, 23, Fig. 2, are replaced by a co-operating pair of star-wheels (51, 52), the upper one (52) of which operates a linkage 60 to actuate a knife (63) and sever the paper-covered adhesive strip 34 in the middle of a length of paper (30), and the clamping arms (41, 42) are not powered but are attached to the guide bars (17, 18) by leaf springs (53, 54).