| 摘要 |
<p>736,697. Wrapping-machines. ROBINSON WAXED PAPER CO., Ltd. Aug. 27, 1953 [Aug. 27, 1952], No. 21556/52. Class 94 (1). In a wrapping-machine in which articles 2 enclosed in wrappers 1 are fed, as by a conveyer 4, between heat-sealing devices 5 which secure the end folds of the wrappers, each device comprises in one form, Fig. 3, a moving endless metallic band 6 with which the surfaces to be sealed make sliding contact. The band passes over a hot-plate 7 and driving rollers 8, coupled by a chain 10, and is moved in the opposite direction to the conveyer 4 or in the same direction at a different, preferably slower, speed so as to provide a continuously changing area of contact with the heat-sealable material of the wrapper. The accumulation of a deposit of thermo-plastic material on the operative surface of the band is thus avoided. One or both rollers may be adjustable for tensioning purposes, and the frame 9 on which the device is mounted may be adjusted relative to the conveyer. The speed of the band is preferably such that it takes about one hour to complete a cycle of movement. The band may be removed for cleaning and a fresh band substituted after each cycle. Alternatively, a wick 11, situated in advance of the hotplate, may be provided to apply a heat-resisting oil to the band, and a scraper 13 and brush 12 may be arranged to bear on the band after it has passed over the hot-plate to remove deposit and apply a solvent or other cleansing agent, so that the band may work continuously without periodical removal. In a modification, Fig. 5, the band is non-continuous and has its ends coiled on drums 10, one drum being driven to pull the band past the hot-plate 7.</p> |
