Patent ID: 8931405
Filing Date: 2015-01-13
Classification: B65B

Abstract:
1. A strapping machine comprising: a machine body having a camshaft and a cam installed on the camshaft; and a reverse tension mechanism comprising: an active wheel rotatably mounted on the machine body and including a clamping portion; a supporting arm including first and second sections spaced in a horizontal direction, with the first section of the supporting aim pivotably connected to the machine body, wherein the supporting arm is pivotable relative to the active wheel, with the supporting arm further including inner and outer surfaces spaced in a thickness direction perpendicular to the horizontal direction, with the second section of the supporting arm including upper and lower ends spaced in a vertical direction perpendicular to the horizontal and thickness directions, with an opening defined between the upper end and the lower end of the second section of the supporting arm, with a spring seat formed on the outer surface of the second section of the supporting arm; a passive wheel rotatably mounted on the inner surface of the first section of the supporting arm and rotatable with the active wheel, with the passive wheel including a clamping portion, with a gap formed between the clamping portion of the passive wheel and the clamping portion of the active wheel for a strapping band to pass through; a lever extending through the opening of the second section of the supporting arm and including first and second ends spaced in the thickness direction, with the first end of the lever having an abutting member abutting against the cam, with the lever having at least one pivot hole disposed between the abutting member and the second end of the lever, with a pivot extending through the second section of the supporting arm and the pivot hole of the lever, wherein the lever is pivotably connected to the second section of the supporting arm and swings about an axis defined by the pivot when the cam turns, with the second end of the lever disposed above the spring seat; and a spring installed between the second end of the lever and the spring seat of the supporting arm in the vertical direction, with the spring compressed in the vertical direction to produce a pushing force to move the supporting arm and the passive wheel when the lever swings.