| 摘要 |
<p>1,002,918. Wrapping-machines; packages. FR. HESSER MASCHINENFABRIK A.G March 24, 1964 [April 25, 1963], No. 12285/64. Heading B8C. [Also in Division B5] Apparatus for heat sealing a wrapper of synthetic material includes a heated die 1 provided with a plurality of blades 2 having sealing surfaces 7, the blades 2 being arranged in spaced parallel relationship with one another and transversely with respect to the longitudinal direction of the die 1 so that a seam formed by the die 1 comprises a plurality of spaced, parallel tacks extending transversely to the whole sealing seam. The blades 2 are connected to a plate 3 formed with apertures 5 to prevent heat accumulation and also to a sleeve 4 joined to the plate 3. The sleeve 4 contains a heating element (not shown) in the bore 6 thereof. The surfaces 7 comprise wedge-shaped extensions of increased height. A U-shape frame is pivotally mounted on the die 1 under the action of compression springs 9. Screw-threaded bolts 10 limit the pivoting movement of the frame 8 in which cooling apertures 11 are provided. In use, an article G is pushed with a wrapper E through a folding tube 12 so that the wrapper E is folded to U-shape around the article. A pusher 13 folds down a first flap and the frame 8 folds down a second flap. As the pusher 13 retracts, the die 1 moves upwardly against the springs 9 and contacts and seals the wrapper E. After sealing, the die 1 is withdrawn, firstly, in a direction opposite to the feed direction of the articles G and then transversely to this direction. To prevent the wrapper E adhering to the frame 8, the latter is covered with a strip of polytetrafluoroethylene or of glass impregnated with polytetrafluoroethylene. Preferably, when the sheets to be sealed have been stretched, the lengthwise direction of each blade 2 extends in the direction in which the sheets have been stretched.</p> |
