초록 ▼

The present disclosure relates to a work unit with power turning. The work unit includes a frame having a first end, a second end and left and right sides that extend between the first and second ends. A work element is carried by the frame. A left propulsion element is positioned at the left side o

The present disclosure relates to a work unit with power turning. The work unit includes a frame having a first end, a second end and left and right sides that extend between the first and second ends. A work element is carried by the frame. A left propulsion element is positioned at the left side of the frame and a right propulsion element is positioned at the right side of the frame. A drive arrangement is carried by the frame for driving the left and right propulsion elements. The work unit also includes left and right spaced-apart leverage arms that project outwards from the second end of the frame. At least one of the left and right leverage arms is operatively connected to the drive arrangement such that pressure applied by an operator to the left or right leverage arms in a left or right direction causes the drive arrangement to turn the work unit.

대표청구항 ▼

1. A work unit with power turning comprising: a frame having a first end, a second end, and left and right sides that extend between the first and second ends;a work element carried by the frame;a left propulsion element positioned at the left side of the frame and a right propulsion element positio

1. A work unit with power turning comprising: a frame having a first end, a second end, and left and right sides that extend between the first and second ends;a work element carried by the frame;a left propulsion element positioned at the left side of the frame and a right propulsion element positioned at the right side of the frame;a drive arrangement carried by the frame for driving the left and right propulsion elements; andleft and right spaced-apart leverage arms that project outwardly from the second end of the frame, at least one of the left and right leverage arms being operatively connected to the drive arrangement such that pressure applied by an operator to the left or right leverage arms in a left or right direction causes the drive arrangement to turn the work unit;wherein the left and right leverage arms are pivotally connected to the frame at separate pivot axes such that the left and right leverage arms can pivot left and right relative to the frame;wherein the left and right leverage arms are linked together so that the left and right leverage arms pivot together as a unit relative to the frame;wherein the left and right leverage arms project outwardly from the frame a distance of at least 12 inches; andwherein the work unit is a walk-behind work unit, wherein the left and right leverage arms angle away from one another as the left and right leverage arms project outwardly from the frame, and wherein the work unit is configured such that the operator stands between the left and right leverage arms as the operator walks with the work unit. 2. A work unit with power turning comprising: a frame having a first end, a second end, and left and right sides that extend between the first and second ends;a work element carried by the frame;a left propulsion element positioned at the left side of the frame and a right propulsion element positioned at the right side of the frame;a drive arrangement carried by the frame for driving the left and right propulsion elements; andleft and right spaced-apart leverage arms that project outwardly from the second end of the frame, at least one of the left and right leverage arms being operatively connected to the drive arrangement such that pressure applied by an operator to the left or right leverage arms in a left or right direction causes the drive arrangement to turn the work unit;wherein the left and right leverage arms are pivotally connected to the frame at separate pivot axes such that the left and right leverage arms can pivot left and right relative to the frame;wherein the left and right leverage arms are linked together so that the left and right leverage arms pivot together as a unit relative to the frame; andwherein the left and right leverage arms are pivotally movable relative to the frame between a left position, a right position and a centered position. 3. The work unit of claim 2, wherein when the left and right leverage arms are in the centered position, the left and right leverage arms respectively angle outwardly in left and right directions as the left and right leverage arms extend outwardly from the frame. 4. The work unit of claim 2, wherein the left and right leverage arms are spring biased toward the centered position. 5. A work unit with power turning comprising: a frame having a first end, a second end, and left and right sides that extend between the first and second ends;a work element carried by the frame;a left propulsion element positioned at the left side of the frame and a right propulsion element positioned at the right side of the frame;a drive arrangement carried by the frame for driving the left and right propulsion elements;left and right spaced-apart leverage arms that project outwardly from the second end of the frame, at least one of the left and right leverage arms being operatively connected to the drive arrangement such that pressure applied by an operator to the left or right leverage arms in a left or right direction causes the drive arrangement to turn the work unit;wherein the left and right leverage arms are pivotally connected to the frame at separate pivot axes such that the left and right leverage arms can pivot left and right relative to the frame;wherein the left and right leverage arms are linked together so that the left and right leverage arms pivot together as a unit relative to the frame; anda control panel positioned at the second end of the frame and a propulsion control member positioned at the control panel, the propulsion control member being movable between a forward position, a neutral position and a reverse position. 6. The work unit of claim 5, wherein the propulsion control member is configured to remain in the forward position and the reverse position without operator assistance so that the operator can grasp both of the left and right leverage arms during forward and reverse movement of the work unit. 7. The work unit of claim 6, further comprising an operator presence detector provided on at least one of the left and right leverage arms. 8. A work unit with power turning comprising: a frame having a front end, a back end, a left side and a right side;a work element carried by the frame;a left propulsion element positioned at the left side of the frame and a right propulsion element positioned at the right side of the frame;a drive arrangement carried by the frame for driving the left and right propulsion elements;a propulsion control member positioned at the back end of the frame, the propulsion control member being operatively connected to the drive arrangement and being movable between a forward position where the drive arrangement causes the left and right propulsion elements to propel the work unit in a forward direction, a neutral position and a reverse position where the drive arrangement causes the left and right propulsion elements to propel the work unit in a reverse direction;left and right spaced-apart leverage arms that project rearwardly from the back end of the frame, the left and right leverage arms being pivotally connected to the frame at separate pivot axes and being pivotally movable relative to the frame between a centered position, a left position and a right position, at least one of the left and right leverage arms being operatively connected to the drive arrangement such that pivoting of the left and right leverage arms provides drive arrangement assisted steering of the work unit; andwherein the left and right leverage arms are linked together so that the left and right leverage arms pivot together as a unit relative to the frame. 9. The work unit of claim 8, wherein the propulsion control member is configured to remain in the forward position and the reverse position without operator assistance so that an operator can grasp both of the left and right leverage arms during forward and reverse movement of the work unit. 10. A work unit with turning comprising; a frame having a front end, a back end, a left side and a right side;a work element carried by the frame;a left propulsion element positioned at the left side of the frame and a right propulsion element positioned at the right side of the frame;a drive arrangement carried by the frame for driving the left and right propulsion elements;a propulsion control member positioned at the back end of the frame, the propulsion control member being operatively connected to the drive arrangement and being movable between a forward position where the drive arrangement causes the left and right propulsion elements to propel the work unit in a forward direction, a neutral position and a reverse position where the drive arrangement causes the left and right propulsion elements to propel the work unit in a reverse direction, wherein the propulsion control member is configured to remain in the forward position and the reverse position without operator assistance so that an operator can grasp both of a left and a right spaced-apart leverage arm during forward and reverse movement of the work unit;wherein the left and right spaced-apart leverage arms project rearwardly from the back end of the frame, the left and right leverage arms being pivotally connected to the frame at separate pivot axes and being pivotally movable relative to the frame between a centered position, a left position and a right position, at least one of the left and right leverage arms being operatively connected to the drive arrangement such that pivoting of the left and right leverage arms provides drive arrangement assisted steering of the work unit; andan operator presence detector provided on at least one of the left and right leverage arms. 11. A work unit with turning comprising: a frame having a front end, a back end, a left side and a right side;a work element carried by the frame;a left propulsion element positioned at the left side of the frame and a right propulsion element positioned at the right side of the frame;a drive arrangement carried by the frame for driving the left and right propulsion elements;a propulsion control member positioned at the back end of the frame, the propulsion control member being operatively connected to the drive arrangement and being movable between a forward position where the drive arrangement causes the left and right propulsion elements to propel the work unit in a forward direction, a neutral position and a reverse position where the drive arrangement causes the left and right propulsion elements to propel the work unit in a reverse direction;left and right spaced-apart leverage arms that project rearwardly from the back end of the frame, the left and right leverage arms being pivotally connected to the frame at separate pivot axes and being pivotally movable relative to the frame between a centered position, a left position and a right position, at least one of the left and right leverage arms being operatively connected to the drive arrangement such that pivoting of the left and right leverage arms provides drive arrangement assisted steering of the work unit; andwherein when the propulsion control member is in the neutral position and the left and right leverage arms are in the left position, the drive arrangement drives the left propulsion element in a forward direction and the right propulsion element in a reverse direction to provide zero radius turning in a clockwise direction, and wherein when the propulsion control member is in the neutral position and the left and right leverage arms are in the right position, the drive arrangement drives the left propulsion element in a reverse direction and the right propulsion element in a forward direction to provide zero radius turning in a counterclockwise direction. 12. The work unit of claim 11, wherein when the propulsion control member is in the forward position and the left and right leverage arms are in the centered position, the drive arrangement drives the left and right propulsion elements forward at a same speed to propel the work unit straight forward, wherein when the propulsion control member is in the forward position and the left and right leverage arms are in the left position, the drive arrangement drives the left propulsion element forwardly at a faster speed than the right propulsion element causing the work unit to turn right as the work unit is propelled forward, and wherein when the propulsion control member is in the forward position and the left and right leverage arms are in the right position, the drive arrangement drives the right propulsion element forwardly at a faster speed than the left propulsion element causing the work unit to turn left as the work unit is propelled forward. 13. The work unit of claim 12, wherein when the propulsion control member is in the reverse position and the left and right leverage arms are in the centered position, the drive arrangement drives the left and right propulsion elements in reverse at a same speed to propel the work unit straight back, wherein when the propulsion control member is in the reverse position and the left and right leverage arms are in the left position, the drive arrangement drives the right propulsion element in reverse at a faster speed than the left propulsion element causing the work unit to turn left as the work unit is propelled backward, and wherein when the propulsion control member is in the reverse position and the left and right leverage arms are in the right position, the drive arrangement drives the left propulsion element in reverse at a faster speed than the right propulsion element causing the work unit to turn right as the work unit is propelled backward. 14. A work unit with power turning comprising: a frame having a front end, a back end, a left side and a right side;a work element carried by the frame;a left propulsion element positioned at the left side of the frame and a right propulsion element positioned at the right side of the frame;a drive arrangement carried by the frame for driving the left and right propulsion elements, the drive arrangement including a first hydraulic pump and a first hydraulic motor for driving the left propulsion element, and a second hydraulic pump and a second hydraulic motor for driving the right propulsion element;a propulsion control member positioned at the back end of the frame, the propulsion control member being operatively connected to the drive arrangement and being movable between a forward position where the drive arrangement causes the left and right propulsion elements to propel the work unit in a forward direction, a neutral position and a reverse position where the drive arrangement causes the left and right propulsion elements to propel the work unit in a reverse direction;left and right spaced-apart leverage arms that project rearwardly from the back end of the frame, the left and right leverage arms being pivotally connected to the frame and being pivotally movable relative to the frame between a centered position, a left position and a right position;a manipulator block coupled to the propulsion control member by a first linkage, the manipulator block being pivotally connected to the frame about a first pivot axis, wherein movement of the propulsion control member between the forward, reverse and neutral positions causes the manipulator block to pivot about the first pivot axis;a pivot member pivotally mounted to the manipulator block, the pivot member being pivotally movable relative to the manipulator block about a second pivot axis;a second linkage that connects the pivot member to the first hydraulic pump and a third linkage that connects the pivot member to the second hydraulic pump, the first and second linkages moving in opposite directions as the pivot member is pivoted about the second pivot axis; anda fourth linkage that couples at least one of the left and right leverage arms to the pivot member, wherein pivotal movement of the left and right leverage arms causes pivotal movement of the pivot member about the second pivot axis. 15. A work unit with power turning comprising: a frame having a front end, a back end, a left side and a right side;a work element carried by the frame;a left propulsion element positioned at the left side of the frame and a right propulsion element positioned at the right side of the frame;a drive arrangement carried by the frame for driving the left and right propulsion elements, the drive arrangement including a first hydraulic pump and a first hydraulic motor for driving the left propulsion element, and a second hydraulic pump and a second hydraulic motor for driving the right propulsion element;a propulsion control member operatively connected to the drive arrangement and being movable between a forward position where the drive arrangement causes the left and right propulsion elements to propel the work unit in a forward direction, a neutral position and a reverse position where the drive arrangement causes the left and right propulsion elements to propel the work unit in a reverse direction;left and right spaced-apart steering members, the left and right steering members being pivotally connected to the frame and being pivotally movable relative to the frame between a centered position, a left position and a right position;a manipulator block coupled to the propulsion control member by a first linkage, the manipulator block being pivotally connected to the frame about a first pivot axis, wherein movement of the propulsion control member between the forward, reverse and neutral positions causes the manipulator block to pivot about the first pivot axis;a pivot member pivotally mounted to the manipulator block, the pivot member being pivotally movable relative to the manipulator block about a second pivot axis;a second linkage that connects the pivot member to the first hydraulic pump and a third linkage that connects the pivot member to the second hydraulic pump, the first and second linkages moving in opposite directions as the pivot member is pivoted about the second pivot axis; anda fourth linkage that couples at least one of the left and right steering members to the pivot member, wherein pivotal movement of the left and right steering members causes pivotal movement of the pivot member about the second pivot axis.