GB684252A - Improvements in or relating to wrapping machines - Google Patents

Abstract

684,252. Labelling. machines. FORGROVE MACHINERY CO., Ltd., and RUSSELL, A. April 2, 1951,. [April 3, 1950] No. 8269/50. Class 73. [Also in Groups XVI, XVII and XXX] In a wrapping-machine (see Group XVII) in which end-seals are applied to packages as they are moved by a step-by-step conveyer (see Group XXX) along a discharge platform 75 between side plates 324, webs of end-seal material 375, consisting of interconnected end-seals 432 coated with thermoplastic adhesive, Fig. 20A, are fed from reels 37, Fig. 20, at each side of the platform 75 by adjustably-mounted intermittently-driven peg rollers 377, the pegs 378 of which engage between adjacent seals. Each roller is rotated by a pawl and ratchet operated through linkage by a push rod 383 which is actuated through a spring 381 and bell-crank 382 by a cam 342. The drive to the rollers is rendered inoperative if a trip member 440 projecting through the platform is not depressed by a package prior to its movement to station H. The leading end of each web is guided by a member 380 into a V groove 433 in the bottom edge of an aperture 376 in each side plate, and end-seals are severed from the webs and pressed against the end fold s of the wrapper by adj ustably-mounted knives 402 and heated pressers 403 carried bv rods 404 which are reciprocated through linkage by an arm coupled to a bell-crank 351. This unites the central portions of the end-seals to the wrapper and causes adhesion of the overlapping end flaps over the central zones of the ends of the package. If the wrapper is not made of heat-sealable material, adhesive is applied by a roller 369 to the undersurafce of the end flap 326 of the wrapper before it is folded. As the package moves from station H, fixed tongues 418 on the plates 324 flatten the end-seals. At station I the sealing of the ends of the package is completed by heated presser members carried by rods 406 which are coupled by cross-heads 407, 408 to the rods 404. These presser members are each formed of two portions arranged to engage the end of the package above and below the zones at which a partial seal was effected at station H. The heat-sealing faces of the presser members are in the form of a flexible grid which acts as an electrical resistor and is caused to assume a convex shape by an insulated spring-loaded plunger. The current to the heaters is controlled by a microswitch operated by the trip member 440. The completed packages are discharged through a shoot at the end of the platform. Specifications 567,196, [Group XVI], 622,593, [Group XVII] and 684,259 are referred to.