Patent ID: 7632200

Claim:
A tensioning device to impart tension to a chain or belt having a first slack strand and a second slack strand, the device comprising: a link bar having a first link end and a second link end; a driving device fixedly mounted and comprising a housing and a driving piston extending from the housing and biased away from the housing, wherein the driving piston drives the link bar; a first tensioner rotatably mounted by a first arm pivot pin and rotatably connected to the first link end of the link bar by a first body pivot pin, the first tensioner comprising: a first tensioner body; and a first tensioner arm extending from the first tensioner body and having a first proximal end with a curved engaged surface formed on a lower surface thereof, a first distal end opposite the first proximal end, and a first arcuately curved strand sliding surface for contacting the first strand and extending between the first proximal end and the first distal end, wherein the first arm pivot pin is located at the first proximal end of the first tensioner arm; and a second tensioner rotatably mounted by a second arm pivot pin and rotatably connected to the second link end of the link bar by a second body pivot pin, the second tensioner comprising: a second tensioner body; and a second tensioner arm extending from the second tensioner body and having a second proximal end with a curved engaged surface formed on a lower surface thereof, a second distal end opposite the second proximal end, and a second arcuately curved strand sliding surface for contacting the second strand and extending between the second proximal end and the second distal end, wherein the second arm pivot pin is located at the second proximal end of the second tensioner arm; wherein the link bar maintains the first body pivot pin at a fixed length apart from the second body pivot pin during a stroke of the link bar; and wherein the driving piston pushing on the biasing surface moves the link bar, simultaneously rotating the first tensioner about the first arm pivot pin to increase tension imparted to the first strand by the first strand sliding surface and rotating the second tensioner about the second arm pivot pin to increase tension imparted to the second strand by the second strand sliding surface.