Patent GB-1353157-A (GB)
Title: Packaging apparatus and method
IPC: B65B31/02
Filed: 1970-11-04
Abstract: 1353157 Vacuum packaging W R GRACE & CO 28 Oct 1971 [4 Nov 1970] 52465/70 Heading B8C Vacuum packaging of articles includes feeding a filled but unsealed bag into a vacuum chamber, evacuating the chamber and then closely gathering the neck of the bag and applying a clip thereto. As shown, articles, e.g. hams, are fed from a conveyer 1 on to a conveyer 2 which advances each article to a photoelectric sensor 3 which when actuated, stops the conveyers 1 and 2 and drives sensing plates 4, 5 into contact with the article to measure the sum of the height and width thereof, from which is derived a signal which is used to illuminate one of four selector lamps 6 positioned in a battery 7 of support trays carrying different sizes of bags. The appropriate sized bag is selected by an operator and the article moves over rollers 41 on to conveyer belts 8, having a slot 8a therebetween, to a sensor assembly 9 so connected that sensor plates 10 engage sides of the article to measure its width, and through a suitable control system, effect lateral separation of pairs of plates 11 defining a guide for a bag applied thereover by the operator. The movement of the plates 11 to open the bag is terminated by micro-switches (not shown) which also advances the article, by means of a pusher located in the slot 8a, into the bat and towards a conveyer assembly 46 comprising parallel conveyer rollers 19, 20 and lateral shift bars 18 whereby a pair of filled bags may be advanced simultaneously into a vacuum chamber. The vacuum chamber includes a pair of feed conveyers 21 separated from main conveyers 22 by a vertically movable sensing roller 24 and a laterally extending track for clipping studs. After the articles are received on the conveyers 22, the roller 24 rises and the conveyers 22 descend a distance equivalent to one half the height of the article and a clip is applied to each bag neck. Subsequently the conveyers 22 again rise and advance the filled bags to a hot water shrinking bath (37), Fig. 5 (not shown) the vertical movements of a hood 26 of the vacuum chamber being synchronized with the vertical movements of the conveyers 22. The clipping operation is performed by a blade 30, Fig. 3 driven by a pneumatic piston and cylinder arrangement 34. The clips are moved from magazines 29 into alignment with a die 35 carried by the hood 26, the closure of which effects partial gathering of the bag necks and evacuation of the bags. Thereafter final gathering takes place and the blade 30 rises to engage free ends of the clips with the die 35 so as to bend them around the bag necks. Vertical severance of surplus bag material is effected by a knife 28. The bath (37) comprises a double-walled tank having a roller conveyer (38), which upon arrival thereon of filled bags, is de-clutched from its drive and is lowered into the tank. Automatic water level sensing is provided and loss of steam from the tank is prevented by a plate (39) below the conveyer (38). A hood (40) sealingly engages the tank (37) when the conveyer is lowered into the tank, and flotation of the articles is prevented by a basket (45) within the hood which may also be provided with forced cooling means for steam trapped therein after the hood is raised.