Enabling system for an implement controller

A system for reliably enabling an implement controller for a work vehicle having a swivel seat with at least two angular positions. The system includes an implement controller for controlling a work implement, seat position detector for determining the positions of the swivel seat, an ignition switch and an implement controller toggle switch. The system is capable of enabling the implement controller under ideal enablement conditions and non-ideal enablement conditions. Ideal enablement conditions exist when the implement controller toggle switch is toggled to an implement controller enabling state while the ignition switch is on and the seat is properly positioned. Non-ideal enablement conditions exit when the implement controller toggle switch is put in an implement controller enabling state in the absence of ideal enablement conditions.

FIELD OF THE INVENTION

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.

BACKGROUND OF THE INVENTION

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.

SUMMARY OF THE INVENTION

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.

DESCRIPTION OF THE ILLUSTRATED EMBODIMENT

FIG. 1illustrates a work vehicle10in which the invention may be used. The particular work vehicle10shown inFIG. 1is a loader backhoe which, typically, has dual functions. The functions of the particular work vehicle10illustrated are that of a backhoe and that of a loader. The work vehicle10includes a cab15, a swivel seat20, at least one implement controller160, a backhoe portion50and a loader portion60. It also includes wheels70as well as a propulsion system (not shown) that propels it along the ground in a manner well known in the art. The swivel seat20has at least two set positions, i.e., swivel angles at which it can be locked. These set positions include at least an angle in which the swivel seat20faces the backhoe portion50and an angle in which the swivel seat20faces the loader portion60; they are usually 180° apart angularly as indicated inFIG. 1. The swivel seat20is in the backhoe or loader operating position when it is within about 15° of each of the set positions, respectively.

FIG. 2is a block diagram outlining an exemplary embodiment of the invention. Included in the diagram are: an ignition switch100; a first seat switch110for indicating whether or not the swivel seat20is in a backhoe operating position; a second seat switch120for indicating whether or not the swivel seat20is in a loader operating position; an implement controller160; an implement controller toggle switch130for enabling the implement controller160which also serves as an override switch; and a logic control device150. The logic control device150may be a conventional on board controller computer for the vehicle, a conventional hardwired switching mechanism or a conventional group of switches and relays arranged to effect the logic of the invention via methods well known to those of ordinary skill in the art.

FIG. 3is a flowchart detailing a control loop200of operating steps for the invention as embodied inFIG. 2. The operating steps set forth inFIG. 3may be incorporated into the hardware and/or software programming of the logic control device150via techniques well known to those of ordinary skill in the art. As shown inFIG. 2as well as inFIG. 3, the entire process begins with step210, i.e., a power-on state for the ignition switch100as this is required to initiate a flow of energy necessary for activating all other switches. As illustrated, if the ignition switch100is in a power-off state in step210, the process ends immediately at step270and the pilot joystick controller160is not enabled. Once the ignition switch100is in a power-on state, the state of the first seat switch110is checked at step220. If the first seat switch110is in a first seat switch first state indicating the swivel seat20is in the backhoe operating position, the process moves to step230to determine the state of the second seat switch120. If the second seat switch120is not in the second seat switch first state then the process moves to step240. If, at step240, the implement controller toggle switch130is then toggled to a toggle switch first state, the implement controller160is ideally enabled implement controller.

If, at step220, the first seat switch110is not in a first seat switch first state or, at step230, the second switch is in a second seat switch first state, the process branches to step270and the implement controller is not enabled unless the implement controller toggle switch130is toggled to the toggle switch first state at step260. If, under these conditions, the implement controller toggle switch140is used as the override switch and toggled to the controller switch first state the process moves to step250, where the implement controller is non-ideally enabled, and branches to280where the operator is informed of a non-ideal enablement via the monitor180through at least one of the display181and the audible sound generator190.

FIG. 4illustrates an accumulator191that increases the reliability of the enabling system. The accumulator191functions as a failsafe mechanism in the event of a catastrophic loss of hydraulic pressure provided by the engine (not shown) and hydraulic pumps (not shown). Such a failure could occur as a result of, for example, engine failure, hydraulic line failure, hydraulic pump failure, etc. Should the supplied hydraulic pressure fail, the accumulator191serves as a temporary pressure sustainer and allows the operator to use the implement controller160to appropriately return the work tool, which is typically a backhoe, to a convenient position such as a stow position.

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 switch110and the second seat switch120. However, comparable results could be obtained with the use of a greater number of seat switches or a single seat switch.