Strapping device

Abstract

A strapping device including a tensioner operable to apply a strap tension to a loop of wrapping strap, a friction welder operable to produce a friction weld connection at two areas of the loop of wrapping strap disposed one on top of the other, a motor operable in a first rotational direction to drive the tensioner and in a second opposite rotational direction to drive the friction welder, and a control device. The control device is configured to, in response to receiving a first designated input: (1) operate the motor in the first rotational direction to drive the tensioner until a predetermined strap tension is reached in the loop of wrapping strap; and (2) afterwards, automatically operate the motor in the second different rotational direction to drive the friction welder to produce the friction weld connection.

1 . A strapping device comprising:
 a tensioner operable to tension a strap;   a strap connector operable to connect two areas of the strap to one another, the strap connector movable from a rest position downward to a connecting position and from the connecting position upward to the rest position;   a transfer device operably connected to the strap connector to move the strap connector from the rest position downward to the connecting position;   a motor comprising a motor shaft, the motor operably connectable to the strap connector and the transfer device at least in part via the motor shaft; and   a control device configured to control the motor to rotate the motor shaft in a first direction to cause the transfer device to move the strap connector from the rest position downward to the connecting position and to cause the strap connector to operate.   
     
     
         2 . The strapping device of  claim 1 , further comprising planetary gearing between the motor shaft and the transfer device. 
     
     
         3 . The strapping device of  claim 2 , further comprising a cam wheel having a cam thereon, wherein the planetary gearing operably connects the motor shaft to the cam wheel such that rotation of the motor shaft in the first direction causes the planetary gearing to cause the cam wheel to rotate. 
     
     
         4 . The strapping device of  claim 3 , wherein the planetary gearing is configured to cause the cam wheel to rotate at a slower rotational speed than the motor shaft. 
     
     
         5 . The strapping device of  claim 4 , wherein the planetary gearing includes one or more planetary gear stages. 
     
     
         6 . The strapping device of  claim 4 , wherein the cam wheel is positioned relative to the transfer device so rotation of the cam wheel causes the cam to actuate the transfer device to move the strap connector from the rest position to the connecting position. 
     
     
         7 . The strapping device of  claim 6 , wherein the transfer device comprises a first arm pivotable between a first position and a second position and a second arm pivotable between a third position and a fourth position. 
     
     
         8 . The strapping device of  claim 7 , wherein the first arm is operably connected to the second arm to pivot the second arm from the third position to the fourth position. 
     
     
         9 . The strapping device of  claim 8 , wherein the second arm is operably connected to the strap connector so movement of the second arm from the third position to the fourth position causes the strap connector to move from the rest position downward to the connecting position. 
     
     
         10 . The strapping device of  claim 9 , wherein the first arm is pinned to the second arm and wherein the second arm is pinned to the strap connector. 
     
     
         11 . The strapping device of  claim 9 , wherein the cam wheel is positioned relative to the transfer device so rotation of the cam wheel causes the cam to contact the first arm and cause the first arm to rotate from the first position to the second position, thereby causing the second arm to move from the third position to the fourth position and the connecting device to move from the rest position to the connecting position. 
     
     
         12 . The strapping device of  claim 11 , further comprising a spring positioned to:
 when the first arm is in the first position, exert a biasing force on the first arm to retain the first arm in the first position; and   when the first arm is in the second position, exert a biasing force on the first arm to retain the first arm in the second position.   
     
     
         13 . The strapping device of  claim 4 , wherein the strap connector comprises a movable welding shoe, a welding shoe arm housing the welding shoe, and an eccentric drive operably connected to the welding shoe to oscillate the welding shoe. 
     
     
         14 . The strapping device of  claim 13 , wherein the motor shaft is operably connected to the eccentric drive such that rotation of the motor shaft in the first direction causes the eccentric drive to rotate at a faster rotational speed than the cam wheel. 
     
     
         15 . The strapping device of  claim 14 , wherein the motor shaft is operably connected to the eccentric drive and to the cam wheel such that rotation of the motor shaft in the first direction causes the cam wheel and the eccentric drive to rotate simultaneously. 
     
     
         16 . The strapping device of  claim 14 , further comprising an output gear and an endless belt operably connecting the output gear to the eccentric drive to rotate the eccentric drive, wherein motor shaft is operably connected to the output gear to rotate the output gear. 
     
     
         17 . The strapping device of  claim 1 , further comprising a rocker lever operably connected to the transfer device so operation of the rocker lever causes the transfer device to move the strap connector from the connecting position upward to the rest position. 
     
     
         18 . The strapping device of  claim 1 , wherein the motor is operably connected to the tensioner such that rotation of the motor shaft in a second direction opposite the first direction causes the tensioner to rotate. 
     
     
         19 . The strapping device of  claim 18 , further comprising:
 a first freewheel between the motor shaft and the strap connector and the transfer device, wherein the first freewheel operably connects the motor shaft to the strap connector and the transfer device when the motor shaft rotates in the first direction and does not operably connect the motor shaft to the strap connector and the transfer device when the motor shaft rotates in the second direction; and   a second freewheel between the motor shaft and the tensioner, wherein the second freewheel operably connects the motor shaft to the tensioner when the motor shaft rotates in the second direction and does not operably connect the motor shaft to the tensioner when the motor shaft rotates in the first direction.   
     
     
         20 . The strapping device of  claim 1 , further comprising a base plate supporting the tensioner, the strap connector, the transfer device, and the motor.