| 摘要 |
1,112,702. Package sealing apparatus. DOUGHBOY INDUSTRIES Inc. 27 July, 1965 [28 July, 1964], No. 32025/65. Heading B8C. [Also inDivision B5] Packages are formed by clamping a longitudinally folded web 15 of heat-sealable material between elongate jaws 31, 32, sealing and severing the web by means of a heated bar 42 thrust through the web between the jaws 31a, 31b, and subsequently withdrawing the heated bar and cooling the severed edges by thrusting against them a conduit 80 carrying a coolant 81. In the embodiment the conduit is mounted rigidly on brackets (82), Fig. 4 (not shown), which move between the spaced clamping members 32a, 32b, Fig. 5. The jaw 31 carries an air conduit 39, having holes (40), Fig. 7 (not shown), and a deflector plate (41) to direct cooling air on to the heated web 15, Fig. 5, on withdrawal of the heated bar. The same jaw also carries coolant conduits 43, 36. Th material-engaging edge portions of the clamping members 32a, 32b are defined by buffers 63 enclosing rubber tubes 65 which bear resiliently against the forward edges of rigid clamping bars 54, 55. The sequence of motion of the jaws, heated bar, and cooling conduit are controlled by levers operated by cams on a common shaft, by which means also a valve controls the supply of cooling air. The web, which may be of polyethylene, is fed from a roll (14), Fig. 1 (not shown), over guide rollers (16, 17) to a drive roller (18) which feeds the web intermittently to spreaders (26), to facilitate insertion of articles (A), and thence to the clamping and sealing device. |
