Grass mowing machines known as ZTR mowers have at least one independently powered drive wheel on each side of a frame. One drive wheel may be operated in a forward direction while the other drive wheel may be stopped or operated in reverse. Many ZTR mowers have a dual lever steering control mechanism. A pair of steering levers or sticks may be provided side-by-side, with each lever or stick controlling one of the drive wheels. When the dual levers or sticks are advanced together forwardly out of their neutral position, both drive wheels rotate forwardly to cause the mower to move forward. A ZTR mower may be steered by advancing one lever or stick more than the other.
Typically, each steering lever or stick on a ZTR mower may be linked to a pump arm of one of two separate hydraulic pumps, or of a dual hydraulic pump; i.e., a separate pump for each wheel. The lever or stick may be used to move a pump swash plate through a direct linkage.
The dual lever steering control mechanism may be mounted on the ZTR frame so that each lever or stick has a first pivot axis allowing the lever or stick in the operating position to pivot forwardly in an arc to turn the wheel in forward, or pivot rearwardly to turn the wheel in reverse. Additionally, each lever or stick may pivot outwardly in an arc from the operating position to a non-operating or parked position. Some dual levers or sticks may pivot outwardly to activate a safety switch which can deactivate the PTO and/or cutting blades, allowing the operator to exit or enter the operator seat or platform.
ZTR mowers are typically equipped several electrical switches that the operator may need to access during operation of the machine. These include electrical switches for the PTO, lights, mower deck lift, etc. However, an operator cannot actuate a switch unless he removes one hand from a steering lever or stick, attempts to steer with his other hand, slows down, and finds the appropriate switch with his or her free hand.
While actuating an electrical switch with his free hand, an operator may have difficulty steering the ZTR mower with his other hand. This is because the inwardly facing ends of the steering levers may be separated by more than about 1-2 inches during a turn. To hold both steering levers with one hand, he or she needs to bring their ends close together, so that their ends are separated by less than about 1 inch. Or the operator may need to stop the ZTR mower. Otherwise, it may be unsafe to actuate a switch while keeping only one hand on the dual lever steering controls. This results in lower efficiency of mowing operations.
There is a need for dual steering levers that allow an operator to actuate an electrical switch while keeping both hands on the steering levers. There is a need to actuate more than one switch at a time while operating a ZTR mower. There is a need to actuate one or more switches while the ZTR mower travels in a straight line, corners, or stops. There is a need for a dual lever steering control mechanism that enhances operator safety, and increases efficiency, during mowing operations.