Patent ID: 6715408
Filing Date: 2004-04-06
Classification: B65B

Abstract:
Strapping machine, comprising:three wheels for driving a strap, said three wheels rotatably mounted on said machine, said three wheels comprising an insertion wheel, a recovery wheel and a tensioning wheel, a movement cam operatively connected to said tensioning wheel, said tensioning wheel made to rotate by said movement cam, three pressure rollers, one pressure roller adjacent each of said three drive wheels, each of said three pressure rollers being displaceable from a rest position in which the respective drive roller is inoperative, to a working position, in which the respective drive roller is bearing by pressure onto the strap and onto the respective drive wheel thereby to perform a drive function, means to adjust the length of the working travel of said tensioning wheel, wherein, said tensioning wheel (6) is made to rotate by the movement cam (7) through a substantially constant angle of rotation â€œaâ€ , corresponding to an arc having a length equal to the maximum tensioning traveling distance of the strap, and said means to adjust the length of the working travel of the tensioning wheel includes means to bring the respective pressure roller into cooperation with the tensioning wheel with a predetermined delay in respect of the starting moment of the rotation â€œaâ€  of the tensioning wheel.