초록 ▼

A neutral start switch arrangement is provided for a work vehicle having a motor driving a hydrostatic pump, the hydrostatic pump driving a hydraulic motor which drives a wheel. The hydrostatic pump typically has an input control shaft, the rotation of which moves the hydrostatic pump from the neutr

A neutral start switch arrangement is provided for a work vehicle having a motor driving a hydrostatic pump, the hydrostatic pump driving a hydraulic motor which drives a wheel. The hydrostatic pump typically has an input control shaft, the rotation of which moves the hydrostatic pump from the neutral position to the forward or reverse drive position. A selectively rotatable control arm is fixed to the input control shaft. A first arm is mounted for rotation about the input control shaft axis. A second arm is mounted for rotation about the input control shaft axis. The control arm and the first and second arms are configured for the control arm to be rotated from a neutral drive position to rotate the first arm in a forward drive rotary direction or the second arm in a second rotary direction corresponding to the reverse drive. A first leg extends from the first arm and a second leg extends from the second arm, and a spring is stretched between the first and second legs. The spring rotationally biases the first arm and the second arm toward each other and both into the neutral position. A neutral start switch is mounted to the first arm to orbit about the input control shaft axis with rotation of the control arm. The switch has a push button actuation portion that is arranged to be actuated by contact with the second arm to change switch states when the control arm is moved into the neutral position.

대표청구항 ▼

1. In a work vehicle having a motor driving a hydrostatic pump, the hydrostatic pump driving a hydraulic motor, wherein the hydrostatic pump comprises an operator-selectable forward drive position and a neutral position, and including an electrical interlock that prevents starting of the motor when

1. In a work vehicle having a motor driving a hydrostatic pump, the hydrostatic pump driving a hydraulic motor, wherein the hydrostatic pump comprises an operator-selectable forward drive position and a neutral position, and including an electrical interlock that prevents starting of the motor when the hydrostatic pump is not in the neutral position, the improvement comprising:the hydrostatic pump having an input control shaft, the rotation of which moves the hydrostatic pump from the neutral position to the forward drive position, a control arm fixed to the input control shaft, a linkage element fixed at one end portion to the control arm at a distance from an axis of rotation of the input control shaft and extending to an opposite end portion where it is engagable to be moved to selectively rotate the input control shaft via said control arm, a first arm mounted for rotation about said input control shaft axis and extending a radial distance from said input control shaft, a neutral start switch mounted to said first arm to orbit about said input control shaft axis with rotation of said control arm, said switch having an actuation portion that is arranged to be actuated to change states when said control arm is in said neutral position. 2. The improvement according to claim 1, wherein said switch actuation portion comprises a push button.3. The improvement according to claim 1, comprising a second arm arranged to be adjacent said first arm when said control arm is in said neutral position and said actuation portion is depressed by contact with said second arm.4. The improvement according to claim 1, wherein said switch is mounted to said first arm by a slotted attachment that can be loosened and adjusted to set a position of said switch with respect to said first arm.5. The improvement according to claim 1, comprising a second arm mounted for rotation about said input control shaft axis and extending a radial distance from said input control shaft axis, and wherein said control arm and said first arm are configured for said control arm to be rotated from a neutral drive position in a first rotary direction to rotate said first arm in said first rotary direction corresponding to one of forward or reverse drive while said second arm is stationary, and said control arm and said second arm are configured for said control arm to be rotated from a neutral drive position in a second rotary direction to rotate said second arm in said second rotary direction corresponding to the respective other of forward or reverse drive while said first arm is stationary, wherein said pressing element is depressed by contact with said second arm when said control arm is in said neutral position.6. The improvement according to claim 5, comprising a first leg extending from said first arm and a second leg extending from said second arm, and a spring stretched between said first and second legs, said spring rotationally biasing said first arm and said second arm toward each other.7. The improvement according to claim 6, comprising at least one abutment that is stationary with respect to said pump casing and interposed between said first and second arms, said at least one abutment preventing said first arm from rotating in the second rotational direction past the neutral position, and preventing said second arm from rotating in the first rotational direction past the neutral position.8. A control arrangement for a hydrostatic transmission pump:the pump having a casing and an input control shaft, the input control shaft penetrating said casing and rotatable about its axis with respect to the casing, having a neutral position and rotatable about its axis in one direction from neutral to initiate forward drive and in an opposite direction from neutral to initiate reverse drive, the control comprising: an operator control mechanism movable by the operator to select neutral, forward or reverse drive; a control arm fixed to said input control shaft for rotation therewith; a linkage having a base portion connected to said control arm at a position displaced from said axis and a distal position arranged to be displaced by selective movement of the operator control mechanism; and an actuating surface and a neutral start switch that is actuated by being in close proximity with said actuating surface, said actuating surface held stationary with respect to said casing and said neutral start switch mounted to orbit about said axis of said input control shaft with rotation of said control arm, said neutral start switch actuated by said actuating surface to change states when said control arm is rotated into said neutral position, said neutral start switch disengaged from said actuating surface when said control arm is rotated out of said neutral position, wherein said neutral start switch is incorporated into a circuit which prevents starting of said engine when said neutral start switch moves out of close proximity to said actuating surface. 9. The control arrangement according to claim 8, wherein said neutral start switch includes a switch button that changes state when it is depressed by said actuating surface and changes state when it is released from said actuating surface.10. The control arrangement according to claim 9, comprising a first arm rotationally mounted at a base end thereof for rotation about said input control shaft axis and extending a radial distance from said input control shaft axis, said neutral start switch mounted to a distal end of said first arm;a second arm rotationally mounted at a base end thereof for rotation about said input control shaft axis and extending a radial distance from said input control shaft axis, said actuating surface provided on said second arm; and wherein said control arm and said first arm are configured for said control arm to be rotated from a neutral drive position in a first rotary direction to rotate said first arm in said first rotary direction corresponding to one of forward or reverse drive while said second arm is stationary, and said control arm and said second arm are configured for said control arm to be rotated from a neutral drive position in a second rotary direction to rotate said second arm in said second rotary direction corresponding to the respective other of forward or reverse drive while said first arm is stationary, wherein said neutral start switch is configured to change the switch state of the neutral start switch when said first and second arms are brought in close proximity, when said control arm is in said neutral position. 11. The control arrangement according to claim 10, wherein said switch is mounted to said first arm by a slotted attachment that can be loosened and adjusted to set a position of said switch with respect to said first arm.12. The control arrangement according to claim 8, comprisinga first arm mounted for rotation about said input control shaft axis and extending a radial distance from said input control shaft axis, said neutral start switch mounted to a distal end of said first arm; a second arm mounted for rotation about said input control shaft axis and extending a radial distance from said input control shaft axis said actuating surface provided on said second arm; and wherein said control arm and said first arm are configured for said control arm to be rotated from a neutral drive position in a first rotary direction to rotate said first arm in said first rotary direction corresponding to one of forward or reverse drive while said second arm is stationary, and said control arm and said second arm are configured for said control arm to be rotated from a neutral drive position in a second rotary direction to rotate said second arm in said second rotary direction corresponding to the respective other of forward or reverse drive while said first arm is stationary, wherein said neutral start switch comprises a pressing element that is depressed to change the switch state of the neutral start switch, and said pressing element is depressed by contact with said actuating surface of said second arm when said control arm is in said neutral position. 13. The control arrangement according to claim 12, comprising a first leg extending from said first arm and a second leg extending from said second arm, and a spring stretch between said first and second legs, said spring rotationally biasing said first arm and said second arm toward each other.14. The control arrangement according to claim 13, comprising at least one abutment that is stationary with respect to said pump casing and interposed between said first and second arms, said at least one abutment preventing said first arm from rotating in the second rotational direction past the neutral position, and preventing said second arm from rotating in the first rotational direction past the neutral position.