Abstract: The apparatus for spiral wrapping a load comprises a carriage which is mounted moveably in the vertical direction on a fixed base-mounted stand and to which two prestretch rollers each coupled with simultaneous rotation with a frictionally engageable wheel and a film supply roll are secured. The downstream prestretch roller and its associated frictionally engageable wheel are carried by a two-arm assembly moveable around a vertical axis and may be moved by moving the member in order to engage or to disengage the frictionally engageable gearing mechanism. A switching assembly which keeps the gearing mechanism disengaged at the beginning of the wrap and thereafter allows an engagement of the friction gearing mechanism until the end of the wrap comprises a base-supported, vertically displaceable and upwardly pretensioned cam member with an upper abutment surface and a lateral cam surface and a switching element coupled rotatably with one arm member of the two-arm member.

Abstract: A method and apparatus in which a predetermined load is placed upon an article prior to securing the article being strapped such as to hold said article together. The apparatus disclosed provides a means for controlling the drive force used to apply pressure to said article before strapping. In the preferred embodiment, an electric motor is mounted on a frame which allows the motor's displacement, relative to the frame of the strapping mechanism caused by the reactional torque of the motor applying force to the article prior to strapping. The measurement of the displacement of the motor relative to the stationary frame is monitored by an electrical apparatus, the output of which is compared to a predetermined value of desired force, thereby switching operation of said motor upon reaching the predetermined force.

Abstract: An improved apparatus is disclosed in which a tensioned plastic strap loop is placed about an article. The invention includes a laterally adjustable forward guide. The guide is pivotally connected to the feed nip of the drive mechanism so as to provide a constant gap between the nip and guide. The rear end of the guide rests upon and moves with the forward gripper. Thus, a guide is provided which minimizes abrasion, can receive straps of different widths, and be easily and quickly cleaned.

Abstract: An improved apparatus is disclosed in which a tensioned plastic strap loop is placed about an article. The invention includes an improved rear guide. The guide is connected to the rear gripper so that it moves with it. The rear guide has a pair of forward and a pair of rear guide members. The forward members are shorter than the rear ones. The forward seal guide members are located so that they are in the middle of the seal region and thus prevent lateral movement of the overlapped strap ends when the heat seal blade is inserted and withdrawn from between them.

Abstract: A band-tensioning device is disclosed which includes an operating lever rotationally fast with an eccentric which is pivotable about a fixed axis. An angle lever is provided which is freely pivotable about the eccentric, and urgeable to rotate therewith by means of the operating lever. A lower portion of the angle lever has an abutment surface which can cooperate with the friction surface of a rotatable tensioning wheel to force a band to be tensioned against the rotating wheel. The pivoting of the eccentric relative to the angle lever displaces it transversely to the abutment surface, so that the surfaces become separated and thus disengaged without having to overcome the high wedging forces associated with the tensioned band between the surfaces. The levers may be coupled by means other than the eccentric, e.g., via an articulated lever, provided the angle lever is selectively movable pivotally or transversely to the abutment surface.

Abstract: A feed device for strapping bands for use in strapping machines is disclosed. A pressure device and a feed roller push the strapping band into a band channel behind the feed roller. A disengaging lever is connected to the pressure device so that when a loop in the band is formed in the band channel, it moves the disengaging lever causing the pressure device to be withdrawn from the band and feed roller permitting the band to reverse direction causing the loop to disappear.

Abstract: An apparatus for securing a tensioned plastic band which has a rotatable tensioning wheel and a friction shoe which is located adjacent a band path for two mutually overlapping end portions of a band located around an article is disclosed. The shoe is reciprocatable transversely to the band path, and displaceable into and out of contact with the upper band end portion. A single drive means is permanently coupled to the shoe for reciprocation, and drives the tensioning wheel via a torque-sensitive coupling. In operation, the shoe is initially out of contact with the band, and the wheel is driven so as to tension the band until a predetermined tension is reached. Thereupon the coupling uncouples, and actuates means which urge the shoe against the band. This causes relative motion of the band ends, resulting in their being frictionally welded together. The uncoupling also actuates a cutting member for the band. Thus the sequence of tensioning, welding and cutting is performed automatically.

Abstract: A device, for feed and tensioning a strapping band about a package in a strapping machine, is disclosed. The machine includes a feed roller which is actuately deflected when the band is placed under tension by a tensioning device. The tensioning device includes a pair of counter rotating v-belts between which the band passes and a pressure device which causes the band to be gripped by the v-belts thus placing it in tension. As the tension on the band increases the pressure exerted by the pressure device is proportionately increased by an angular lever to which the feed roller is connected, which in turn acts on a slidable rod which, through a toggle lever, actuates the pressure device. The machine also includes a sealing and cutting device which is actuated subsequent to the tensioning of the band and which, through a rocker lever, causes the toggle lever to release the pressure on the pressure device prior to the cutting of the rear end of the band.