Single belt drive for a three-spindle rotary mower

In a power transmission for a mower having a downwardly open housing with a generally horizontal deck, the combination comprising:

• three vertical spindles rotatably supported on said deck in a triangular pattern with upper ends disposed above said deck and lower ends disposed below said deck, one of said spindles being disposed forward of the other two spindles and said other two spindles being disposed on laterally opposite sides of said one spindle,
• a cutting blade secured to said lower end of each of said spindles for rotation therewith,
• a driven pulley secured to said upper end of each of said spindles for rotation therewith,
• a drive pulley disposed on a vertical axis spaced forwardly of said triangular pattern and said one spindle,
• grooves in each of said driven and drive pulleys adapted to receive a V-belt,
• a clutch idler lever pivotally mounted on said housing for movement about a generally upright axis between a drive establishing position in which said belt is tightened and a nondriving position in which said belt is relaxed, said lever having a radially extending arm,
• a clutch idler pulley rotatably supported on said arm for rotation about an axis spaced from said upright axis and from the axes of rotation of said spindles,
• a belt idler pulley mounted on said housing,
• a single continuous V-belt trained around said pulleys and having but a single arc of contact with each pulley, respectively, said V-belt having tapered driving surfaces in contact with said grooves of said drive and driven pulleys and a flat backside in contact with said clutch idler pulley and said belt idler pulley, said belt being free of severe twists and crossovers in its installed condition on said pulleys and sequentially engaging said pulley on said one spindle, said clutch idler pulley, said belt idler pulley and said drive pulley.

In a power transmission for a mower having a downwardly open housing with a generally horizontal deck, the combination comprising:

• three vertical spindles rotatably supported on said deck in a triangular pattern with upper ends disposed above said deck and lower ends disposed below said deck, one of the spindles being disposed forward of the other two spindles and said other two spindles being disposed on laterally opposite sides of said one spindle,
• a cutting blade secured to said lower end of each of said spindles for rotation therewith,
• a driven pulley secured to said upper end of each of said spindles for rotation therewith,
• a drive pulley disposed on a vertical axis spaced forwardly of said triangular pattern and said one spindle,
• grooves in each of said driven and drive pulleys adapted to receive a V-belt,
• a clutch idler lever pivotally mounted on said housing for movement about a generally upright axis between a drive establishing position in which said belt is tightened and a nondriving position in which said belt is relaxed, said lever having a radially extending arm,
• a clutch idler pulley rotatably supported on said arm for rotation about an axis spaced from said upright axis and from the axes of rotation of said spindles,
• a fixed axis idler pulley rotatably mounted on said housing,
• a single continuous V-belt trained around said pulleys and having but a single arc of contact with each pulley, respectively, said V-belt having tapered driving surfaces in contact with said grooves of said drive and driven pulleys and a flat backside in contact with said clutch and fixed axis idler pulleys, said belt being free of severe twists and crossovers in its installed condition on said pulleys and sequentially engaging said pulley on said one spindle, said clutch idler pulley, said fixed axis idler pulley and said drive pulley.

In a mower movable in a predetermined forward direction during a mowing operation having a downwardly open housing with a generally horizontal deck, the combination comprising:

• three vertical spindles rotatably supported on said deck in a triangular pattern with upper ends disposed above said deck and lower ends disposed below said deck, one of said spindles being disposed forward of the other two spindles and said other two spindles being disposed on laterally opposite sides of said one spindle,
• a cutting blade secured to said lower end of each of said spindles for rotation therewith,
• a driven pulley secured to said upper end of each of said spindles for rotation therewith,
• a drive pulley disposed on a vertical axis spaced forwardly of said triangular pattern and said one spindle,
• grooves in each of said driven and drive pulleys adapted to receive a V-belt,
• an idler pulley on said housing rearwardly of said one spindle, said idler pulley sloping upwardly from rear to front at an angle less than 15 degrees,
• a single continuous V-belt trained around said pulleys and having but a single arc of contact with each pulley, respectively, said V-belt having tapered driving surfaces in contact with said grooves of said drive and driven pulleys and a flat backside in contact with said idler pulley, said belt being free of severe twists and crossovers in its installed condition on said pulleys, said belt sloping upwardly from said idler pulley to said drive pulley at a slope corresponding substantially with said slope of said idler pulley.