GB916428A - Packaging with variations of package length - Google Patents

Abstract

916,428. Wrapping-machines. CLOUD, C. E. Aug. 21, 1959 [Oct. 16, 1958], No. 28592/59. Class 94(1). A wrapping machine, Fig. 3, has a continually rotating member 23 to which at least one unit 21 can be coupled to move therewith and perform an operation on a wrapping 20 that moves along part of the path of the member 23, the unit 21 following a cycle of movement that returns it to a rest position where it is released from the member 23 until it is again required. The wrapping material commences as a film 10, Fig. 1, that is drawn from a roll 11 past a photocell 13 scouring marks made on the film, said marks being spaced apart according to the size of the article to be packed in the film. Articles to be wrapped are fed by a belt conveyer 16 on to the film 10 as it moves along a table 17 the feeding of the articles being controlled by a magnetic stop 18 that may be controlled by the photocell 13. The film 10 and the articles thereon pass through a tubeforming unit 19 and on to a turret where the unit 21 performs an end-sealing and severing operation. As shown in Fig. 3 the turret comprises a continuously moving disc member 23 and a plurality of the units 21 which initially line up behind a stop-bar 22 that prevents them from rotating with the member 23. Each unit 21 carries a wrapper clamping arm 24 that can pivot transversely to the direction of movement of the unit, this arm in the rest position of the unit 21, being held in a raised position by cam rails 81. When the photocell 13 is operated by a mark on the film 10, the stop-bar 22 is temporarily withdrawn to permit the first of the units 21 assembled at the rest station to seize the turret disc 23 and to move therewith. This movement of the unit 21 causes a part 26 of the cam rails 81 to lower the pivoted clamping arm 24 to a nearly closed position between adjacent articles in the tubular package. The unit 21 then carries the arm 24 below a hinged plate 27 whereafter it is pressed firmly to a closed position by a pressure cam 28 to effect a transverse heat seal, the heating means 77, Fig. 6, being in the unit 21. Each clamping arm 24 carries a severing blade 31 which is movable therein and shortly before discharge of the packages, the unit 21 passes a freely rotatable thrust drum 32 which presses the knife blade 31 inwardly to cut the tube within its sealed area, so that the tube remains heat sealed on both sides of the line of severance. The severed package 33 then drops to a conveyer 36 which, together with a conveyer 37, removes the completed package. The clamping arm 24 is then released by the pressure cam 28, so that it hangs vertically, whereupon it is again caught up by the cam rails 81 as the unit 21 returns to its rest position. Adjustments and control. Since the units 21 do not seize the continually rotating turret disc 23 until a signal is received from the electric eye unit 13, any sized article can be packaged provided that a packaging reel 11 is used that has appropriately spaced marks thereon for the size of the articles to be packed. Should a clamping arm 24 fall upon an article, instead of between adjacent articles, it will then deflect the hinged plate 27 as it passes thereunder to operate a switch and stop the machine. Instead of the stop gate 18 being controlled by the electric eye 13, it may be controlled by a trigger lever 91 seen at the 12 o'clock position in Fig. 3, this trigger being actuated by the passing units 21. Tube forming unit. As the clamping arms 24 pull the packaging material along the table 17, the packaging material is drawn about the articles to be packaged and the edges of the material then enter a Vee-notch where they are caught up under a pair of spring loaded rollers 11, Fig. 11, set to drag the packaging material tightly about the article to be packaged. As the Vee-notch narrows the edge portion of the wrapper that are eventually pressed together are heat sealed by a unit, preferably between two hinged clamps, biassed together by gravity and having sledlike runners engaging the wrapper. Clutch units. The units 21 are carried on rollers that ride in grooves formed in the turret disc 23 and by one member 65, Fig. 5, that is flattened on opposite sides so that when it is in the full line 'position it will ride freely in the groove 58 and when pivoted to the broken line position it will act on a clutch in the groove 58 to releasably seize the turret drive disc 23. Motion is in the direction of the arrow. The clutch member 65 is fast on its shaft and to this shaft is secured a clutch lever 67, the lever being pushed forwardly by a spring 68 in the unit 21 to urge the clutch member 65 to bind in the groove 58. As the units 21 queue behind the stop member 22, the lever of the leading unit 21 is pressed against the stop member 22, and the levers 67 of the other units in the queue are each pressed against the next unit ahead, thus releasing the units 21 from the continually rotating disc turret.