Methods and apparatus for making sacks or bags

Claim 3

Apparatus comprising first means for forming single-ply or multi-ply tubes for the outer sacks; second means for advancing and transversely cutting a simple flat or tubular web of material for the insert sacks; a tube-forming apparatus for forming the webs of the outer and insert sacks into a tube; a transverse perforating apparatus arranged upstream of the tube-forming apparatus, for transversely perforating said outer sack web; a glueing mechanism for applying glue to said outer sack web, arranged upstream of the tube-forming apparatus; a tearing-off apparatus arranged downstream of said tube-forming apparatus; an apparatus arranged downstream of said second means for feeding the portions which are cut off from the simple flat or tubular web of material for the insert sacks; and a conveyor means which in operation moves at the speed of conveyance of said outer sack web and which lays the portions of insert sack material onto the outer sack web, the arrangement of the conveyor means being such that the portions of insert sack material are laid onto the web of outer sack material along the section of the latter which extends between said transverse perforating apparatus or glueing mechanism and said tube-forming apparatus; wherein a double-belt conveyor comprising an upper conveyor belt and a lower conveyor belt is disposed between said second means and said conveyor means, which double-belt conveyor in operation moves at a higher speed than the conveyor means, and wherein at least one belt roller of the pair of belt rollers at the end of the double-belt conveyor at which said insert sack portions are transferred to the conveyor means is reciprocatable in the direction of conveyance of the portions of insert sack material in the rhythm of the machine, with tensioning rollers engaging the outer run for maintaining the tension in the belt, and wherein a folding plate means is provided which is also reciprocatable and which in the foremost position extends with its folding edge into the entry nip of said conveyor means along a transverse line lying in the region of the leading end, for introducing an insert sack portion into the converging entry nip of said conveyor means, and prematurely releasing the trailing end.

Claim 4

Apparatus comprising first means for forming single-ply or multi-ply tubes for the outer sacks; second means for advancing and transversely cutting a simple flat or tubular web of material for the insert sacks; a tube-forming apparatus for forming the webs of the outer and insert sacks into a tube; a transverse perforating apparatus arranged upstream of the tube-forming apparatus, for transversely perforating said outer sack web; a glueing mechanism for applying glue to said outer sack web, arranged upstream of the tube-forming apparatus; a tearing-off apparatus arranged downstream of said tube-forming apparatus; an apparatus arranged downstream of said second means for feeding the portions which are cut off from the simple flat or tubular web of material for the insert sacks; and a conveyor means which in operation moves at the speed of conveyance of said outer sack web and which lays the portions of insert sack material onto the outer sack web, the arrangement of the conveyor means being such that the portions of insert sack material are laid onto the web of outer sack material along the section of the latter which extends between said transverse perforating apparatus or glueing mechanism and said tube-forming apparatus; wherein a double-belt conveyor comprising an upper conveyor belt and a lower conveyor belt is disposed between said second means and said conveyor means, which double-belt conveyor in operation moves at a higher speed than the conveyor means, and wherein at least one belt roller of the pair of belt rollers at the end of the double-belt conveyor at which said insert sack portions are transferred to the conveyor means is reciprocatable in the direction of conveyance of the portions of insert sack material in the rhythm of the machine, with tensioning rollers engaging the outer run for maintaining the tension in the belt, and wherein a folding plate means is provided which is also reciprocatable and which in the foremost position extends with its folding edge into the entry nip of said conveyor means along a transverse line lying in the region of the leading end, for introducing an insert sack portion into the converging entry nip of said conveyor means, and prematurely releasing the trailing end.

Claim 5

Apparatus according to claim 2 wherein the folding plate means comprises a folding plate supported on the lower belt of the double-belt conveyor so as to be movable between an upwardly directed working position and a downward inoperative position.

Claim 6

Apparatus according to claim 2 wherein the lower conveyor belt of the double-belt conveyor comprises a plurality of stands and the folding plate means comprises a folding plate of a comb-like conStruction supported at a position lying in the interior of the space enclosed by the lower conveyor belt of the double-belt conveyor, the comb-like fingers projecting between the individual strands of the conveyor belt and being movable to a position in which they extend beyond the reciprocatable belt roller.

Claim 7

Apparatus according to claim 4 wherein the comb-like folding plate is pivotally connected at its rearward end to an actuating linkage by way of which a movement in the direction of conveyance is imparted thereto in the rhythm of the reciprocating movement of said reciprocatable belt roller.

Claim 8

Apparatus according to claim 5 wherein said actuating linkage comprises a pivotally mounted double lever which has its first ends pivotally connected to a respective side of the comb-like folding plate, while its second ends are free; spring means for urging the lever towards a position in which the folding plate is in a retracted rest position, the lever being pivotally mounted at its pivot point in a bearing which is movable with said reciprocatable belt roller; and adjustable stop means arranged in the path of movement of said free ends of the lever, in the region of the forward end of the movement of said reciprocatable belt roller, the stop means co-operating with the lever during the forward movement of the pivot point of the lever until the one stroke movement of the reciprocating motion of said belt roller is completely terminated, whereby the double lever and thus the folding plate are moved in the direction of movement of said reciprocatable belt roller, overtaking the latter, into a forward working position against the force of said spring means.

Claim 9

Apparatus according to claim 2 wherein said conveyor means is in the form of a double-belt conveyor having an upper belt guided in the region of its entry end by means of two guide rollers such that a wedge-shaped entry nip is produced, and wherein a further roller is disposed on the inside of the belt run (nip run) spanning across the entry nip, which further roller is movable transversely relative to the nip run and which can be pressed into and removed again from the nip run in the working rhythm of the machine, whereby in operation the nip run is opened and closed in the rhythm of the machine.

Claim 10

Apparatus according to claim 7 wherein the upper belts of the double-belt conveyor and the conveyor means are each in the form of a strand belt, the strands of both upper belts are guided at the adjacent ends of the upper belts by means of band pulleys with a common centre, and wherein of the double-belt conveyor only the front roller of the lower belt carries out said reciprocating movement.

Claim 11

Apparatus according to claim 2 wherein said conveyor means is in the form of a double-belt conveyor having an upper belt passing in the region of the entry end over two guide rollers such as to form a wedge-shaped entry nip, and wherein a roller is arranged adjacent the conveyor section formed by the upper belt jointly with the lower belt, the roller being so arranged that it can be resiliently flexibly pressed outwardly into the two adjoining runs of said upper belt.

Claim 12

Apparatus according to claim 9 wherein the upper belts of the double-belt conveyor and the conveyor means are each in the form of a strand belt, the strands of both upper belts are guided at the adjacent ends of the upper belts by means of band pulleys with a common centre, and wherein of the double-belt conveyor only the front roller of the lower belt carries out said reciprocating movement.

Claim 13

Apparatus according to claim 2 wherein said lower belt is in the form of a strand belt and wherein said folding plate means is of a ladder-like construction with an elongate continuous folding bar and supported at a position lying within the volume enclosed by the lower conveyor belt of said double-belt conveyor, the rungs of the ladder-like construction projecting between the individual strands of said lower belt, movably beyond the reciprocatable belt roller.