Abstract: A tensioner assembly pre-stretches a film web prior to unitizing a pallet load. The film web undergoes three stages of stretching by the tensioner assembly which includes two driven rollers and a resiliently biased dancer roller. The dancer roller engages the film and maintains it under continuous tension loading as the pallet load rotates. An electrical control signal proportional to the angular position of the dancer roller is employed by a control circuit to vary the rotational speed of the pretensioner drive rollers. The film web is stretched in a first stage between a feedstock roll and the first drive roller. A second stage of stretching occurs between the first driven roller and the second driven roller. Finally, the film web undergoes a third stage of stretching between the second driven roller and the pallet load, with the web being maintained under tension at all times by the resiliently biased dancer roller.

Abstract: An improvement is disclosed in wrapping apparatus for palletized loads of the kind having a rotatable platform where the load is received, and a roll of plastic film mounted adjacent to the platform for vertical movement so that plastic film can be dispensed onto the load while the platform rotates, in order to enwrap the load helically. The improvement is the provision of an elongated roller member pivoted adjacent one of its ends to the platform so that is can swing between two positions through an arc in a vertical plane. In the first position the member bears against a frictional surface on the platform, and in the second position it is spaced from the frictional surface. In swinging from the second to the first position at the end of a wrapping operation, the elongated roller member catches the film and pinches it between itself and the frictional surface.

Abstract: There is provided an apparatus for wrapping a film around a palletized load, in which the main operative portions are suspended above the load, in order to save space. A central driven shaft extends downwardly from a frame which is supported above the wrapping location, and the shaft supports and rotates a radially extending arm from the distal end of which a downward member extends. A vertically reciprocating carriage mounted on the downward member carries a roll of film, which is dispensed as the roll is carried in a circular path to orbit around the load. Where the width of the film is less than the height of the load, the carriage is reciprocated while orbiting, so that a helical wrapping procedure can be accomplished. A similar but non-reciprocating carriage permits the wrapping to be performed using a film width equal to the height of the load as an alternative embodiment.