Tensioning arrangement having a swinging arm

An apparatus (10) for imparting tension to multiple strands of an endless loop power transferring member (12) to conform to a radius of curvature of spaced apart devices (14, 16a, 16b) rotatable about respective spaced apart axes of rotation, and each device (14, 16a, 16b) having a drive face radially spaced from an axis of rotation for intended power transferring engagement of the endless loop power transferring member (12) between the spaced apart devices (14, 16a, 16b), the apparatus comprising:

• at least one moveable tensioning arm (18a, 18b), each moveable tensioning arm having a first pivot location end (24a, 24c) and a second pivot location end (24b, 24d) for rotation with respect to a corresponding pivot pin (30a, 30b, 30c, 30d);
• at least two swing arms (20a, 20b, 20c, 20d) for each tensioning arm (18a, 18b), each swing arm (20a, 20b, 20c, 20d) pivotally connected at one end to the corresponding pivot pin (30a, 30b, 30c, 30d) and pivotally connected at an opposite end to a corresponding fixed pivot pin (26a, 26b, 26c, 26d) for defining a predetermined path of movement for the at least one moveable tensioning arm (18a, 18b);
• a protrusion (64) formed on at least one of the swing arms (20a, 20b, 20c, 20d) extending outwardly from the corresponding fixed pivot pin location (26a, 26b, 26c, 26d) and spaced angularly from the corresponding pivot location (30a, 30b, 30c, 30d) of the corresponding connected moveable tensioning arm (18a, 18b);
• and
• a tension driver (50) engaging the protrusion (64) for driving the corresponding connected moveable tensioning arm (18a, 18b) in motion for tensioning the endless loop power transferring member (12) nearly simultaneously and nearly equally on both strands.

In an apparatus (10) for imparting tension to multiple strands of an endless loop power transferring member (12) to conform to a radius of curvature of spaced apart devices (14, 16a, 16b) rotatable about respective spaced apart axes of rotation, and each device (14, 16a, 16b) having a drive face radially spaced from an axis of rotation for intended power transferring engagement of the endless loop power transferring member (12) between the spaced apart devices (14, 16a, 16b), the improvement comprising:

• two moveable tensioning arm (18a, 18b) spaced apart from one another for movement with respect to one another, each moveable tensioning arm having a first pivot location end (24a, 24c) and a second pivot location end (24b, 24d) for rotation with respect to a corresponding pivot pin (30a, 30b, 30c, 30d);
• two swing arms (20a, 20b, 20c, 20d) for each of the two tensioning arms (18a, 18b), each swing arm (20a, 20b, 20c, 20d) pivotally connected at one end to the corresponding pivot pin (30a, 30b, 30c, 30d) and pivotally connected at an opposite end to a corresponding fixed pivot pin (26a, 26b, 26c, 26d) for defining a predetermined path of movement for the corresponding connected moveable tensioning arm (18a, 18b);
• a link assembly (60) including two link members (32a, 32b) pivotally connected to one another at respective first ends (40a, 40b), the connected first ends (40a, 40b) constrained for limited movement along a fixed slot (36) extending generally along a centerline of the endless loop power transferring member (12) between the spaced apart devices (14, 16a, 16b), the two link members (32a, 32b) pivotally connected individually to outer opposite ends (28a, 28b) of the two moveable tensioning arms (18a, 18b) at second locations (42a, 42b) spaced from the first ends (40a, 40b);
• and
• a tension driver (50) for driving the link assembly (60) and connected tensioning arms (18a, 18b) in motion for tensioning the endless loop power transferring member (12) nearly simultaneously and nearly equally on both strands.