| 摘要 |
<p>There is disclosed a bale wrapper apparatus (10) for applying a pre-stretched film (11) around a bale (12) of rectangular cross-section in order to form an air tight and water tight wrapping. The apparatus comprises a platform (15) which rotates about a vertical axis (16), and a pair of rollers (17, 18) mounted on the platform to rotate about horizontal axes (19) and over which slack belts (20 and 21) are taken and which define a trough shape into which the rectangular section of the bale can be received with the upper and lower sides (22, 23) disposed substantially horizontally. A support (24) is mounted on the chassis (12a) and carries a film dispenser reel (25) and a film pre-stretcher mechanism (26) and after attachment of the leading end of the film to the bale by manual or automatic means, combined rotation of the bale about vertical axis (16) and about a horizontal axis causes the film to be withdrawn and wrapped in generally helical fashion around the outer periphery of the bale. In order to compensate for possible variation in angular velocity of the rotating bale, by reason of its rectangular cross-section, (and the difficulties of engaging it uniformally with the slack belts (20, 21)), a guide arrangement (27) is arranged above one of the rollers (17) in order to engage edge regions (28) on the longer sides of the bale cross-section and thereby prevent the bale from falling onto the roller (17), and also retarding the angular rotation of the bale. The function of the guide arrangement therefore is to act on the tumbling rotation of the bale so as to maintain a substantially uniform rate of angular velocity during each revolution of the bale, whereby substantially uniform helical windings of film can be applied around the bale, despite its rectangular cross-section.</p> |
