GB1169922A - Wrapping Machine - Google Patents

Abstract

1,169,922. Wrapping-machines; feeding webs. FRANKLIN ELECTRIC CO. Inc. 9 Nov., 1966 [16 Nov., 1965], No. 50303/66. Headings B8C and B8R. A wrapping machine includes a film feed mechanism comprising a film roll support and film tensioning means between the roll support and the wrapping mechanism, a stripper roller between the roll support and the tensioning means and drive means connected to the stripper roller for intermittently rotating both the film roll and the stripper roller to cause the latter to strip off film. The surface friction alone between the stripper roller and the film is sufficient to permit such stripping. General arrangement of machine.-Articles are fed into the machine by a chain conveyer 61 Fig. 1, on to an elevator 71. The elevator 71 is coupled to a second upper elevator 72 by beams 73, 74 pivoted at their centres. The elevator 71 rises with an article until it is level with the descending elevator 72. Wrapper film from a roll 123 passes over feed and tensioning means to a roller 177 from which it passes down between the two elevators, its free end resting on a support 179, see also Fig. 18. A plunger 83 forces the article from the elevator 71 to elevator 72 whereby the film is wrapped round it. The elevator 72 includes the usual end tuckers (not shown) for the protruding film. When the article is on the elevator 72, a dancer roller 178 descends to carry the film round the article. A pusher 82 pushes the wrapped article off the elevator 72 and on to a plate 81 beneath the leading edge of which is means for severing the film, Fig. 27. It also passes over a tack sealer 291, Fig. 1. A conveyer 312 moves the packages past means to complete the wrapping in the usual manner, vertically movable rollers 332, Fig. 1, pressing each package against a belt running over a heater 318 to seal the bottom overlap seam. A shoot 336 conducts the completed packages away. Web feed.-The film roll is mounted on an arbour 122, Fig. 1, connected by a chain drive to a stripper roller 136, see also Fig. 4, the drive including a slip clutch arrangement 151, 152. The point at which the clutch slips is variable by a hand operated knob 154. Bands 171 of friction material surround the roller. The film passes over the roller 136 and over a roller 166 to a roller 167 on tension arms 170 beneath one-way check mechanism 176, over a roller 177 and to the dancer roller 178. The arms 170 are swung by wrapping film demand to operate switch means starting up the arbour and roller drive. The surface speed of the roller 136 is slightly greater than that of the film roll when the latter is new. The restraining action of the film causes slippage of the stripper roller clutch. This slippage increases as the film roll diameter decreases. Web control.-The dancer roll 178, Figs. 10, 22, is non-rotatable but has a series of rotatable rings 231 mounted on it. Between the rings are lines of holes 232 through which air jets are directed on the web portions to keep them apart. Air jets from a fixed tube 236 also perform this function. In another arrangement, Figs. 35,36,42 a series of rods 361 depend from the dancer roller 178c and are engaged by the web as the article is elevated and are turned against spring bias to the vertical position. When the web is cut, they turn back to the downwardly directed position carrying with them the free end of the web. The roller may be supported by lifts 193c attached to the elevator 72, described in Specification 1,029,495. In a further arrangement, a suction manifold (346), Figs. 24-28 (not shown), depends from the upper elevator (72a) and attracts the cut end of the web before descending to the midposition. In Fig. 29, another device is shown in which opposed electro-static charges are applied to the web and a plate 351 depending from the elevator 72b, by means 352. The plate 351 then functions in the same manner as the suction manifold. Sealing devices.-The tack sealer, Fig. 8, consists of a stationary heated roller 296 with a loosely fitting conducting roller 301. As the article moves over it, the roller rotates to present an initially cooler area to the web overlap, the area heating up to sealing temperature as the article dwells. As the article again moves a cooler area of the roller moves to the contacting position. For the final seal, a stationary heater 318' Fig. 1, is covered by a non-stick belt (321) moving at the speed of the article, Fig. 15 (not shown).