Tensioning apparatus

A tensioning apparatus for a belt, the tensioning apparatus comprising:

• a pulley defining an outer surface to receive the belt;
• a trolley including a mount configured to support the pulley for rotation and an interior cavity;
• a biasing member disposed within the interior cavity;
• and
• an adjustable length arm assembly including a fixed-length portion and an adjuster portion, wherein the fixed-length portion defines an adjustment axis, the fixed-length portion includes a pivot mount for rotatably mounting the tensioning apparatus, wherein the adjuster portion includes a fastener threaded to the fixed-length portion, and the adjuster portion includes an engagement member that engages and deforms the biasing member in response to adjustment of the fastener along the adjustment axis,
• wherein a first interface is defined between a cross section profile of the trolley and a cross section profile of the adjustable length arm assembly at a location of axial overlap along the adjustment axis of the trolley and the adjustable length arm assembly,
• wherein the first interface includes an excess clearance that is set to achieve a predetermined rotational allowance of the trolley about the adjustment axis relative to the adjustable length arm assembly.

A tensioning apparatus for a belt, the tensioning apparatus comprising:

• a pulley defining an outer surface to receive the belt;
• a trolley including a mount configured to support the pulley for rotation, a first end and a second end opposite the first end, and an interior cavity;
• a biasing member disposed within the interior cavity;
• and
• an adjustable length arm assembly including a fixed-length portion and an adjuster portion, wherein the fixed-length portion defines an adjustment axis, the fixed-length portion includes a pivot mount for rotatably mounting the tensioning apparatus, wherein the adjuster portion includes a first fastener threaded to the fixed-length portion, and the adjuster portion includes an engagement member that engages and deforms the biasing member in response to adjustment of the first fastener,
• wherein the biasing member is disposed between an interior of the trolley and an exterior of the adjustable length arm assembly, wherein the biasing member engages the engagement member and the first end of the trolley such that the trolley is moveable on the adjustable length arm assembly along the adjustment axis in response to the biasing member expanding.