Mechanism for controlling position of discharge blocking flap for rotary mowing deck

An apparatus for controlling the position of a pivotally mounted blocking plate located on the discharge opening of the cutting deck on a rotary lawn mower, comprising:

• a) a blocking plate mounted pivotally to said cutting deck at the discharge opening such that in the closed position the plate substantially prevents the discharge of clippings from the cutting deck and in the open position the plate substantially clears the discharge opening allowing the discharge of clippings from the cutting deck,
• b) a fixed pivot joint 1 with axis of rotation wherein said pivot joint 1 connects said blocking plate to the cutting deck,
• c) a blocking plate balance position along the rotational path of the blocking plate between the blocking plate closed position and the blocking plate open position where said blocking plate's motion, once stopped, will not begin again without an external force acting on the plate,
• d) a converting means for converting a motion supplied by a mower operator into a pulling force,
• e) a connecting means for transferring the pulling force to the blocking plate,
• Whereby said operator can control the position of the blocking plate using a like motion to alternately rotate the plate from the open position to the closed position and from the closed position to the open position.

A method for controlling the position of a pivotally mounted blocking plate located at the discharge opening of the cutting deck of a rotary lawn mower, comprising:

• a) providing a blocking plate mounted pivotally to the cutting deck at a fixed pivot joint 1 at the discharge opening such that in the closed position the plate substantially prevents the discharge of clippings from the cutting deck and in the open position the plate substantially clears the discharge opening allowing the discharge of clippings from the cutting deck,
• b) Providing a blocking plate balance position along the rotational path of the blocking plate between the blocking plate closed position and the blocking plate open position where said blocking plate's motion, once stopped, will not begin again without an external force acting on the plate,
• c) providing a linkage member with two ends, the first end being connected pivotally to said blocking plate at a rotating pivot joint 2 and the second end to be locally exposed to a pulling force by a mower operator,
• d) providing a pivot joint 2 connecting said linkage to the blocking plate and positioned such that the axis of rotation of pivot 2 is:
• i) substantially parallel to the axis of rotation of the pivot joint 1, and
• ii) is located with respect to the blocking plate such that the axis of rotation of pivot joint 2 lies in the force plane formed by the intersection of the pulling force, force vector extending from the first end of the linkage member and the axis of rotation of pivot joint 1, when the blocking plate is positioned such that when the blocking plate is in motion said blocking plate's rotational momentum will power the plate past the balance position,
• whereby a variable pulling force applied axially at said second end of said linkage and controlled by the mower operator along with the blocking plate's momentum will rotate the blocking plate in a forward direction from the closed position past the balance position to an at rest open position, said pulling force being cyclical, said pulling force starting at zero when first applied, reaches a maximum as the blocking plate approaches the balance position where the force is released allowing the blocking plate's momentum to carry said blocking plate past the balance position to the open position, once the blocking plate is in the open position said variable pulling force can again be applied to rotate the blocking plate in a reverse direction from the open position back toward the balance position where said blocking plate's rotational momentum will carry the plate to an at rest closed position.

An apparatus for controlling the position of a pivotally mounted blocking plate located on the discharge opening of the cutting deck on a rotary lawn mower comprising:

• a) a blocking plate mounted pivotally to said cutting deck at the discharge opening such that in the closed position the plate substantially prevents the discharge of clippings from the cutting deck and in the open position the plate substantially clears the discharge opening allowing the discharge of clippings from the cutting deck, said blocking plate having a balance position along the rotational path of the blocking plate between the blocking plate closed position and the blocking plate open position where said blocking plate's motion, once stopped, will not begin again without an external force acting on the plate,
• b) a fixed pivot joint 1 with axis of rotation wherein said pivot joint 1 connects said blocking plate to the cutting deck,
• c) a linkage member with two ends, the first end being connected pivotally to said blocking plate and the second end to be locally exposed to a pulling force by mower operator,
• d) a rotating pivot joint 2 connecting said linkage member to said blocking plate wherein the axis of rotation of pivot joint 2 is:
• i) substantially parallel to the axis of rotation of pivot joint 1, and
• ii) is located with respect to the blocking plate such that the axis of rotation of pivot joint 2 lies in the force plane formed by the intersection of the pulling force, force vector extending from the first end of the linkage member and the axis of rotation of pivot joint 1, when the blocking plate is positioned such that when the blocking plate is in motion said blocking plate's rotational momentum will power the plate past the balance position,
• whereby a variable pulling force applied axially at the second end of said linkage and controlled by the mower operator along with the blocking plate's momentum will rotate the blocking plate in a forward direction from the closed position past the balance position to an at rest open position, the pulling force being cyclical, said variable pulling force starting at zero when first applied to a maximum as the blocking plate approaches the balance position where the force is released allowing the blocking plate's momentum to carry the blocking plate past the balance position to the open position, once the blocking plate is in the open position said variable pulling force can again be applied to rotate the blocking plate in a reverse direction from the open position back toward the balance position where said blocking plate's rotational momentum will carry the plate to an at rest closed position.