The invention relates to work vehicles having multiple position swivel seats and implement controllers that are easily operated. More particularly, the invention relates to loader backhoes with easily operated implement controllers.
Traditional control systems for backhoes have included floor mounted hydraulic levers with a sufficient resistance to movement and an adequate distance from the swivel seat to avoid inadvertent operation. Some have included rudimentary enablement conditions, e.g., an operator's presence switch that detects a weight on the vehicle seat, to activate the traditional controllers. Still others have included systems with pilot controllers that automatically enable and disable the pilot controllers in accordance with seat orientation, i.e., enablement typically requires a seat orientation in the direction of the controls to be enabled.
Many modern controllers such as, for example, pilot controllers and electro-hydraulic controllers (hereafter implement controllers) are, by their very nature, easy to manipulate and conventional enablement systems may not provide adequate assurance that the backhoe tool will be manipulated only by deliberate acts of the operator. Accentuating this problem is the fact that the controller towers on which the implement controllers are usually mounted tend to be relatively close to the seat.
The invention provides an enabling system giving greater assurance than conventional systems that the operator will manipulate the backhoe tool only in a deliberate manner. The enabling system accomplishes this by requiring the existence of enablement conditions and a deliberate act of the operator for enablement of the implement controllers. There are two types of implement controller enablement according to the invention: (1) ideal enablement; and (2) non-ideal enablement.
Ideal enablement requires the following enablement conditions: (1) the swivel seat, often associated with backhoes, is in a backhoe operating position and not in another operating position; (2) the ignition switch is in a power on state; and (3) an implement controller toggle switch is toggled to a state for implement controller enablement while ideal enablement conditions (1) and (2) exist. Thus, ideal enablement of the implement controller occurs only if the operator toggles the implement controller toggle switch to the state for implement controller enablement after and while power is on in the work vehicle and the seat is in the backhoe operating position. If, after implement controller enablement, any one of the conditions change, the implement controller is automatically disabled. The implement controller is ideally re-enabled only after the ideal enabling conditions are, once again, established.
Non-ideal enablement requires the following conditions: (1) the swivel seat is not in the backhoe operating position; (2) the ignition switch is in a power on state; and (3) the implement controller toggle switch is toggled to a state for implement controller enablement while non-ideal enablement conditions (1) and (2) are true. Thus, non-ideal enablement is, in essence, an override condition in which the implement controller toggle switch acts as an override switch. The operator is reminded that non-ideal enablement is in effect via a visual alert from a display of a monitor and/or an audible sound from a speaker of a monitor. The reminder may be a singular one time alert, a periodic alert or a constant alert.
The non-ideal enablement allows the operator to perform multiple functions when necessary. Thus, an operator may swivel his seat to the loader operating position or to a position between the backhoe operating position and the loader operating position and manipulate his shovel or move his vehicle while, at the same time, manipulating his backhoe work tool. Swiveling the seat into or out of any position disables the implement controller requiring re-enablement before control is, once again, established.
The enabling system achieves the best results when the vehicle is functioning properly but may be required during a malfunction of the vehicle. Thus, an option is provided in which an accumulator maintains backup hydraulic pressure for the backhoe functions allowing the operator to lower the backhoe instrument to the ground in a controlled fashion should the engine stop or fail.
Embodiments of the invention will be described in detail, with references to the following figures, wherein:
If, at step 220, the first seat switch 110 is not in a first seat switch first state or, at step 230, the second switch is in a second seat switch first state, the process branches to step 270 and the implement controller is not enabled unless the implement controller toggle switch 130 is toggled to the toggle switch first state at step 260. If, under these conditions, the implement controller toggle switch 140 is used as the override switch and toggled to the controller switch first state the process moves to step 250, where the implement controller is non-ideally enabled, and branches to 280 where the operator is informed of a non-ideal enablement via the monitor 180 through at least one of the display 181 and the audible sound generator 190.
Having described the illustrated embodiment, it will become apparent that various modifications can be made without departing from the scope of the invention as defined in the accompanying claims. For example, the means for seat position detection has, thus far, included two seat switches, i.e., the first seat switch 110 and the second seat switch 120. However, comparable results could be obtained with the use of a greater number of seat switches or a single seat switch.