Strapping apparatus

Abstract

A strapping apparatus for strapping articles with a strapping band having a tensioning device for imparting a band tension to a loop of the strapping band, the tensioning device including a driveable tensioning element provided for engaging the strapping band to impart a band tension. The strapping apparatus including a connecting device for generating a permanent connection, in particular a welded connection, at two regions, situated one above the other, of the loop of the strapping band. The strapping apparatus is configured to achieve the release of the tensioning element from the strapping band reliably to avoid or reduce adverse characteristics attributed to the release of the tensioning device from the band.

What is claimed is: 
     
         1 . A strapping device comprising:
 a tensioning wheel rotatable about a tensioning axis;   a motor configured to rotate the tensioning wheel about the tensioning axis in a tensioning direction;   a contact partner indirectly connected to the tensioning wheel;   a wrap spring;   a first component operably connected to the wrap spring such that movement of the first component from a first position to a second position causes at least part of the wrap spring to increase in diameter; and   a second component movable to cause the first component to move from the first position to the second position;   wherein the wrap spring frictionally engages the contact partner when the first component is in the first position to fix the contact partner in rotation relative to the tensioning wheel such that the tensioning wheel can rotate in the tensioning direction to tension strap around an object and, after tensioning, is prevented from rotating in a direction opposite the tensioning direction,   wherein the frictional engagement between the wrap spring and the contact partner is at least partially eliminated when the first component arm moves from the first position to the second position such that the contact partner is rotatable to enable the tensioning wheel to rotate in a direction opposite the tensioning direction.   
     
     
         2 . The strapping device of  claim 1 , wherein the wrap spring comprises multiple windings, where movement of the first component from the first position to the second position causes diameters of successive windings of the wrap spring to gradually widen. 
     
     
         3 . The strapping device of  claim 1 , wherein the contact partner comprises a first contact partner, the strapping device further comprising a second contact partner fixed in rotation, wherein the wrap spring frictionally engages the second contact partner when the first component is in the first position. 
     
     
         4 . The strapping device of  claim 1 , wherein the second component is pivotable to cause the first component to move from the first position to the second position. 
     
     
         5 . The strapping device of  claim 4 , wherein the second component is pivotable to contact the first component to force the first component to move from the first position to the second position. 
     
     
         6 . The strapping device of  claim 1 , wherein the first component is rotatable from the first position to the second position. 
     
     
         7 . The strapping device of  claim 6 , wherein the wrap spring has a wrap-spring rotational axis, wherein the first component is rotatable about the wrap-spring rotational axis. 
     
     
         8 . The strapping device of  claim 7 , wherein the contact partner is rotatable about the wrap-spring rotational axis. 
     
     
         9 . The strapping device of  claim 8 , wherein the second component is pivotable about a pivot axis to cause the first component to move from the first position to the second position,
 wherein the pivot axis is parallel to the wrap-spring rotational axis.   
     
     
         10 . The strapping device of  claim 9 , wherein the pivot axis is parallel to the tensioning axis. 
     
     
         11 . The strapping device of  claim 6 , wherein the wrap spring comprises a first end, a second end, and multiple windings between the first end and the second end, wherein the first end of the wrap spring is fixed in rotation with the first component. 
     
     
         12 . The strapping device of  claim 11 , wherein the wrap spring has a wrap-spring rotational axis, wherein the second end of the wrap spring is fixed in rotation about the wrap-spring rotational axis. 
     
     
         13 . The strapping device of  claim 1 , wherein the frictional engagement between the wrap spring and the contact partner is entirely eliminated when the first component is moved from the first position to the second position. 
     
     
         14 . The strapping device of  claim 1 , wherein the first component comprises multiple first teeth and wherein the second component comprises multiple second teeth. 
     
     
         15 . The strapping device of  claim 14 , wherein the second component is movable to cause the second teeth to mesh with the first teeth to drive the first component to move from the first position to the second position. 
     
     
         16 . The strapping device of  claim 15 , wherein the second component is movable from a home position to an actuated position to cause the first component to move from the first position to the second position, wherein the second teeth are disengaged from the first teeth when the second component is in the home position. 
     
     
         17 . The strapping device of  claim 16 , wherein the first component comprises a sleeve and wherein the second component comprises a pivotable arm. 
     
     
         18 . The strapping device of  claim 17 , further comprising a hand lever operably connected to the second component to cause the second component to pivot. 
     
     
         19 . The strapping device of  claim 1 , further comprising a base, a rocker, and a tensioning plate, wherein the rocker supports one of the tensioning wheel and the tensioning plate, wherein the rocker is movable relative to the base to change a distance separating the tensioning wheel and the tensioning plate. 
     
     
         20 . The strapping device of  claim 1 , further comprising a friction welder.