Patent GB-1338704-A (GB)
Title: Apparatus for compressing and packaging stacks of sheet articles
IPC: B65B25/14
Filed: 1971-07-08
Abstract: 1338704 Apparatus for compressing and packaging stacks of sheet articles WINDMOLLER&HOLSCHER 8 July 1971 [13 July 1970] 32206/71 Heading B8C Apparatus for compressing and packaging stacks of flattened bags, or similar sheet articles, comprises a compression chamber 81 having a bottom opening to receive a stack therethrough, a plunger 82 for introducing the stack into the chamber 81 together with a web F1, F2 of packing material disposed across the bottom opening of the chamber 81 and to compress the stack against a backing member 87 of the chamber 81, the plunger 82 being reciprocable in a vertical, or steeply inclined direction, a folding device 83 to close the web F1, F2 about the compressed stack, and means 84 for joining the web ends to form a packaging sleeve about the stack. The folding device comprises a flat frame 83 which is reciprocable, by means of cylinders 96, 96<1>, to lie beneath, or laterally clear of the bottom opening in the chamber 81 and which carries freely-rotatable rollers 95 which extend at their ends between roller tracks 97, 98 and 97<1>, 98<1> in slotted frames 99,99<1> respectively, the spacing X between the roller tracks of each pair being larger than the diameter of a roller 95. The frames 99, 99<1> are vertically displaceable by pressure drives 106, 107 the arrangement being such that the rollers 95 contact the upper and lower roller tracks 97, 97<1> and 98, 98<1> respectively during operative and return strokes of the slide member 83, the operative stroke being from right to left in Fig. 1. The slide member 83 carries a ramp 101 which supports a guide roll 102 for a sheet of packaging material F1 which is unwound from a supply reel 103 and is joined, by a transverse weld seam S, to a sheet F2 of packaging material unwound from a supply reel 104 to form a web for wrapping about the stack. In operation a stack St is raised by the plunger 82 and is introduced into the chamber 81 through the bottom opening thereof, stack carrying the web F1, F2 with it into the chamber 81, being compressed between the plunger 82 and the backing member 87 initially to an extent regulated by a reduction valve 94 in the feed line to a pressure cylinder 91 which controls the vertical position of the backing member 87. When the plunger 82 reaches its uppermost position flush with the tops of the rollers 95, the backing member 87 is displaced upwardly, under the greater pressure of the plunger 82 relative to that exerted by the backing member 87. The slide member 83 now executes its operative stroke to close the web F1, F2 about the bottom of the compressed stack, the rollers 95, in contact with the upper tracks 97, 97<1>, rotating clockwise, Fig. 1, and the plunger 82 being simultaneously moved away from the compression chamber in the same direction and at the same speed as the slide member 83. When the latter has reached its left hand limiting position 95<11> the web is closed about the stack by the separating and welding apparatus 84 which also forms a continuous web for packaging the next stack. After the seam has cooled a value 93 is operated to lift the backing member 87 off the stack St, the frames 99, 99<1> are displaced upwardly so that the rollers 95 coact with the lower tracks 98<1>, 98, and the slide member 83 is withdrawn to the right, Fig. 1. In this manner the stack is withdrawn through the side opening of the compression chamber 81 at a greater speed than that of the slide member 83 because, at this time, the rollers 95 are rolling along the tracks 98<1>, 98 to rotate in the direction of the arrow d. The package rolls off the rollers 95 and slides down the ramp 101 to a conveyer, not shown. During withdrawal of the stack the plunger 82 is moved downward and towards the right to receive the next stack.