Patent ID: 8608601

Claim:
A tensioning device for imparting a tensioning force to a chain having a first chain span and a second chain span, the tensioning device comprising: a first tensioner arm comprising: a first arm part slidingly receiving the chain, the first arm part extending in an arcuate shape along and outside the first chain span, the first arm part having a first pivoting end pivotably supported by a first spindle and a first free end; and a first flange part integral with the first arm part and projecting toward the internal space between the first chain span and the second chain span; a second tensioner arm comprising: a second arm part slidingly receiving the chain, the second arm part extending in an arcuate shape along and outside the second chain span, the second arm part having a second pivoting end pivotably supported by a second spindle and a second free end; and a second flange part integral with the second arm part, projecting toward the internal space between the first and second chain spans, and overlapping the first flange part; a linking part pivotably linking the first flange part and the second flange part, the linking part comprising: a first long hole formed through a portion of the second flange part overlapping the first flange part; and a protrusion linked to the first flange part, engaging the first long hole, and slideable in the first long hole; and urging means for urging the first free end of the first tensioner arm toward the first chain span; and when the urging means urges the first free end of the first tensioner arm toward the first chain span, the first flange part of the first tensioner arm causes the second flange part of the second tensioner arm to pivot by way of the linking part, so that the second arm part of the second tensioner arm moves toward the second chain span.