Method and apparatus for a two speed strap take up

An apparatus usable for a strap take up of a strap useable within a strapping machine, the apparatus comprising:

• a high speed roller assembly having a high speed roller continuously rotatable in one operational direction by a high speed rotatable drive shaft disposable in a journal box, the high speed rotatable drive shaft rotatable by a power drive train said power drive train continuously operable in said same one direction;
• a low speed roller assembly having a low speed roller continuously rotatable in another operational direction by a low speed rotatable drive shaft disposable in a journal box said another operation direction opposite to said one direction, the strap being disposable between and frictionally engaged by the high speed roller and the low speed roller;
• a reduction gear assembly having a reducing gear disposed about the low speed rotatable drive shaft, the reduction gear assembly interconnecting the high speed rotatable drive shaft and the low speed rotatable drive shaft, the low speed rotatable drive shaft being rotated by the reduction gear at a reduced rotation rate relative to the high speed rotatable drive shaft;
• means for allowing the low speed rotatable drive shaft to rotate at a rotation rate greater than the reduced rotation rate relative to the high speed rotatable drive shaft;
• means for allowing the high speed roller to slip relative to the high speed rotatable drive shaft when a first and continuously progressive tension is applied to the strap disposed between the high speed roller and the low speed roller and when said first tension progressively attains a first pre-determined tension value and a first take up speed;
• means for allowing the low speed roller to slip relative to the low speed rotatable drive shaft when a second and continuously progressive tension which said second tension is greater than the first tension, is applied to the strap disposed between the high speed roller and the low speed roller and when said second tension progressively attains a second pre-determined tension value and a second strap take up speed, said second tension being applied to said strap until said low speed roller slips relative to said low speed drive shaft.

A method for two speed strap take up usable in a strapping machine, the method comprising steps of:

• simultaneously engaging a strap between a high speed roller and a low speed roller, the high speed roller being continuously rotated in one operational direction by a high speed drive shaft and the low speed roller being rotated continuously at substantially a same rotation rate as the high speed roller and in another operational direction, said another direction being opposite to said one direction;
• slipping the high speed roller relative to the high speed drive shaft when a first and continuously progressive tension is applied to the strap and when said first tension progressively attains a first pre-determined value and a first take up speed;
• rotating the low speed roller by a low speed drive shaft when the high speed roller slips relative to the high speed drive shaft, wherein the low speed drive shaft is being driven at a reduced rotation rate relative to the high speed drive shaft by a reducing gear assembly interconnecting the high speed drive shaft and the low speed drive shaft;
• and
• slipping the low speed roller relative to the low speed drive shaft when a second and continuously progressive tension which said second tension is greater than the first tension, is applied to the strap and when said second tension progressively attains a second pre-determined value and a second take up speed.