Patent Publication Number: US-2021172154-A1

Title: Hybrid control for a backhoe loader

Description:
FIELD OF THE DISCLOSURE 
     The disclosure relates to the field of backhoe loaders. 
     BACKGROUND 
     A backhoe loader is a machine that comprises a loader generally towards the front of the machine and a backhoe generally towards the back of a machine. A typical backhoe loader is shown in  FIG. 1 . A cab is located between the loader and the backhoe. A seat in the cab is generally rotatable such that an operator can face forwards to drive the machine and operate the loader or can face backwards to operate the backhoe. 
     Conventionally, a pair of backhoe control sticks is provided to operate the backhoe and these are usually mounted between the seat and the rear of the cab. The exact positions of the pair of backhoe control sticks may be adjustable to provide easier access to the seat and for operator comfort. Conventionally, one loader control stick is provided to operate the loader and this is usually mounted between the seat and the front of the cab. The exact position of the one loader control stick may be adjustable to provide easier access to the seat and for operator comfort. 
     Accordingly, three control sticks may be provided in total. 
     When facing forwards, the pair of backhoe control sticks will be behind the seat and, when facing backwards, the loader control stick will be behind the seat. Accordingly, access to at least one of the control sticks is always restricted. A skilled operator may be able to operate a control stick located behind the seat but this may be uncomfortable and, in any case, freedom of movement of the operator may be limited such that precision control may be difficult. 
     SUMMARY OF THE DISCLOSURE 
     Against this background, in a first aspect there is provided a backhoe loader comprising:
         a cab having a seat assembly including a seat for an operator;   a loader assembly to a front side of the cab; and   a backhoe assembly to a rear side of the cab;   wherein the seat assembly comprises:
           a first control stick on a first side of the seat, the first control stick configured to output a first set of electronic signals; and   a second control stick on a second side of the seat opposite the first side, the second control stick configured to output a second set of electronic signals;   
           wherein the seat assembly is rotatable between a first position in which the seat assembly faces the rear side of the cab and a second position in which the seat assembly faces the front side of the cab; and   the backhoe loader further comprising:   a seat assembly orientation sensor; and   an electronic controller having a default setting in which:   in an event that the seat orientation sensor determines that the seat assembly is in the first position, electronic signals from both the first and second control sticks are directed to control operation of the backhoe assembly; and   in an event that the seat orientation sensor determines that the seat assembly is in the second position, electronic signals from the first control stick are directed to control operation of the loader assembly.       

     In this way, functionality of the first and second control sticks may be dependent upon seat orientation. 
     In a second aspect, there is provided a backhoe loader comprising:
         a cab having a seat assembly including a seat for an operator;   a loader assembly to a front side of the cab; and   a backhoe assembly to a rear side of the cab;   wherein the seat assembly comprises:
           a first control stick on a first side of the seat, the first control stick configured to output a first set of signals; and   a second control stick on a second side of the seat opposite the first side,   
           the second control stick configured to output a second set of signals;   wherein the seat assembly is rotatable between a first position in which the seat assembly faces the rear side of the cab and a second position in which the seat assembly faces the front side of the cab;   the backhoe loader further comprising an electronic controller having a hybrid setting in which:   electronic signals from the first control stick are directed to control operation of the loader assembly and electronic signals from the second control stick are directed to control operation of the backhoe assembly.       

     In this way, simultaneous control of both the loader assembly and the backhoe assembly may be facilitated using the first and second control sticks. 
     In a third aspect, there is provided a backhoe loader comprising:
         a cab having a seat assembly including a seat for an operator;   a loader assembly to a front side of the cab; and   a backhoe assembly to a rear side of the cab;   wherein the seat assembly comprises:
           a first control stick on a first side of the seat, the first control stick configured to output a first set of electronic signals; and   a second control stick on a second side of the seat opposite the first side, the second control stick configured to output a second set of electronic signals;   
           an electronic controller having first, second and third selectable modes, wherein:   in the first mode, electronic signals from both the first and second control sticks are directed to control operation of the backhoe assembly;   in the second mode, electronic signals from the first control stick are directed to control operation of the loader assembly; and   in the third mode, electronic signals from the first control stick are directed to control operation of the loader assembly and electronic signals from the second control stick are directed to control operation of the backhoe assembly.       

     In this way, first and second control sticks may be used for any of the following: to control the backhoe assembly; to control the loader assembly; and in a hybrid configuration to control both the backhoe assembly and the loader assembly. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A specific embodiment of the disclosure will now be described, by way of example only, with reference to the accompanying drawings in which: 
         FIG. 1  shows a side view of a backhoe loader in accordance with the prior art; 
         FIG. 2  shows control stick functionality in accordance with the prior art adopting a conventional backhoe style (Option 1); 
         FIG. 3  shows control stick functionality in accordance with the prior art adopting a conventional excavator style (Option 2); 
         FIG. 4  shows a side view of a backhoe loader in accordance with the disclosure; 
         FIG. 5  shows a seat assembly within a cab of a backhoe loader in accordance with the disclosure; 
         FIG. 6  shows the seat assembly of  FIG. 3 ; 
         FIG. 7  shows control stick functionality in three different control modes in accordance with the disclosure; 
         FIG. 8  shows default availability and alternative availability of the three different control modes depending upon seat assembly orientation in accordance with an embodiment of the disclosure; 
         FIG. 9  shows in more detail control stick functionality for loader control in Mode 2 in accordance with an embodiment of the disclosure; 
         FIG. 10  shows in more detail control stick functionality for backhoe control (Modes 1 and 3) inspired by a conventional backhoe style (Option 1) in accordance with an embodiment of the disclosure; and 
         FIG. 11  shows in more detail control stick functionality for backhoe control (Modes 1 and 3) inspired by a conventional excavator style (Option 2) in accordance with an embodiment of the disclosure. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  shows a conventional backhoe loader  100  in accordance with the prior art. 
     The backhoe loader comprises a cab  110  from which an operator may operate the backhoe loader. The backhoe loader further comprises a loader assembly  120  forward of the cab  110  and a backhoe assembly  130  rearward of the cab  110 . The backhoe assembly  130  may comprise a boom  132  hingedly attached, at a first end of the boom  131 , to the machine  100  via an attachment  111 . The backhoe assembly  130  may further comprise an arm  135  hingedly attached at a first end of the arm  134  to a second end of the boom  133  opposite the first end of the boom  131 . The arm  135  may comprise a coupling  137  by which an implement such as a bucket  138  may be attached to the arm  135 . 
     The loader assembly  120  may comprise a coupling  122  enabling attachment of a loader bucket  121  or other implement, for example forks. 
     The cab  110  comprises a seat assembly  200  rotatable between a forward facing orientation (as shown in  FIG. 1 ) in which the seat assembly faces the loader assembly  120  and a rearward facing orientation (not shown) in which the seat assembly faces the backhoe assembly  130 . 
     In the forward facing orientation, the operator faces regular driving controls such as accelerator, brake and steering wheel  201 . In addition, in the forward facing orientation the operator has access to a loader control stick  210  by which the loader assembly  120  may be controlled. It is common for the loader control stick  210  to be towards a right side of a main cab console. 
     In a known arrangement, the loader control stick  210  may be moved forwards and backwards to lower and raise the loader assembly  120 , respectively. In the known arrangement, the loader control stick  210  may be moved left and right to tilt the loader implement (e.g. loader bucket  121  or forks) upwards and downwards, respectively. In this way, an operator can control the loader assembly  120  using loader control stick  210 . 
     In the rear facing orientation, the operator faces first and second backhoe control sticks  220 ,  230  by which the backhoe assembly  130  may be controlled. The first backhoe control stick  220  may be located on a right side of a rear console within the cab  110  and the second backhoe control stick  230  may be located on a left side of the rear console within the cab  110 . 
     In a first known arrangement, the first backhoe control stick  220  may be moved left and right to curl the bucket  138  and dump the bucket  138 , respectively, and may be moved forwards and backwards to move the arm  135  out and in, respectively. In the first known arrangement, the second backhoe control stick  230  may be moved left and right to swing the boom  132  left and right, respectively, and may be moved forward and backwards to move the boom  132  down and up, respectively. This first known arrangement is commonly adopted in backhoe loaders. 
     A summary of the control functionality in the first known arrangement is illustrated in  FIG. 2 . 
     In a second known arrangement, the first backhoe control stick  220  may (as in the first known arrangement) be moved left and right to curl the bucket and dump the bucket  138 , respectively, and may (by contrast with the first known arrangement) be moved forward and backwards to move the boom  132  down and up, respectively. In the second known arrangement, a second backhoe control stick  230  may (as in the first known arrangement) be moved forwards and backwards to move the arm  135  out and in, respectively, and may (by contrast with the first known arrangement) be moved left and right to swing the boom  132  left and right, respectively. This second known arrangement is commonly adopted in excavators. 
     A summary of the control functionality in the first known arrangement is illustrated in  FIG. 3 . 
     In both first and second known arrangements, eight functions are available for controlling the backhoe assembly  130  using first and second backhoe control sticks  220 ,  230  (four functions on each of the two backhoe control sticks  220 ,  230 ). As such, an operator may control eight functions of the backhoe assembly  130  the two control sticks  220 ,  230 . 
     In the arrangements so far described, if an operator is facing backwards then both backhoe control sticks  220 ,  230  are in front of the operator while the loader control stick  210  is behind the operator. Conversely, if an operator is facing forwards then the loader control stick  210  is in front of the operator but the first and second backhoe control sticks  220 ,  230  are behind the operator. Given that when an operator is facing either backwards or forwards at least one control stick is behind the operator this may limit access to the controls and/or may restrict the precision of operation achievable by the operator. 
     In the arrangements so far described, the control sticks  220 ,  230  are frequently hydraulic control sticks wherein the control sticks  220 ,  230  provide mechanical control of hydraulic valves and actuators that drive the backhoe actuators and drive the loader actuators. 
       FIG. 4  shows a backhoe loader  400  in accordance with the present disclosure.  FIG. 5  shows a plan view of a seat assembly  300  of the backhoe loader of  FIG. 4  in the context of the cab  110 .  FIG. 6  shows a perspective view of just the seat assembly  300  of the backhoe loader  400  of  FIG. 4 . 
     In accordance with the present disclosure, instead of three control sticks ( 210 ,  220 ,  230 ), one of which is located towards the front of the cab  110  and two of which are located towards the rear of the cab  110 , there are two control sticks (first and second control sticks  310 ,  320 ) which are located on opposite sides (right and left) of the seat assembly  300  and which rotate with the seat assembly  300 . 
     Rather than each control stick having a fixed functionality, the functionality of the first and second control sticks  310 ,  320  is dependent upon additional factors. 
     This may be made possible by using electronic control sticks that drive an electronic controller which then drives hydraulics, rather than by having control sticks that mechanically actuate hydraulic valves. In this way, variable functionality is enabled by the electronic controller rather than by altering hydraulic connections. 
     One factor that may determine the functionality of the first and second control sticks may be the direction in which the seat assembly  300  is facing. A seat orientation sensor may be provided for providing a seat orientation signal by which control stick functionality may be influenced. 
     There may be first, second and third modes of operation, shown schematically in  FIG. 7 . In a first mode, only backhoe control may be available. In a second mode, only loader control may be available. In a third mode, a hybrid of backhoe and loader control may be available. 
     In the first mode, signals from both the first control stick  310  and second control stick  320  are used to control operation of the backhoe assembly  130 . This would replicate what may be ordinarily expected by an operator using a machine in accordance with the prior art shown in  FIG. 1  (using the details set out in respect of either first or second known arrangements explained above). 
     In the second mode, signals from the first control stick  310  may be directed to control operation of the loader assembly  120  while signals from the first control stick  320  may remain unused. This would replicate what may be ordinarily expected by an operator using a machine in accordance with the prior art shown in  FIG. 1  (or a dedicated loader machine). 
     In the third mode, hybrid functionality may be provided whereby (a) signals from the second control stick  320  may be used to control operation of the loader assembly  120  and (b) signals from the first control stick  310  may be used to control operation of the backhoe assembly  130 . 
     One consequence of this hybrid functionality is that, since only one of the two control sticks  310 ,  320  is available for backhoe operation, only four functions are possible rather that the eight that would be achievable with two control sticks for backhoe operation. 
     The four functions available with the single backhoe control stick may be boom down, boom up, arm out and arm in. Accordingly, swing left, swing right, bucket curl and bucket dump may not be available. The reason for the choice of available functions may be related to the usefulness of those functions for the purpose of movement of the machine (e.g. in a line parallel to a trench being dug). In other words the available functions may be those which facilitate use of the backhoe to lift the rear wheels of the machine off the ground and then use the backhoe to propel the machine on its front wheels. 
     Which mode is active at any particular time may be dependent upon factors including (a) seat assembly orientation (b) safety trigger and (c) manual override of default function to select alternative functionality. An example implementation of mode availability is shown in  FIG. 8 . 
     For example, the first mode may be available by default if the seat orientation sensor determines that the seat assembly  300  is in a rearward orientation (such that backhoe control is fully available when facing the backhoe assembly  130 ). The second mode may be available by default if the seat orientation sensor determines that the seat assembly  300  is in a forward facing orientation (such that loader control is available when facing the loader assembly  120 ). 
     It may be that the first mode is also available by default if the seat orientation sensor determines that the seat assembly is in neither a forward facing nor a rearward facing orientation. An operator is likely to move into or out of the seat when it is at a midway position between forwards and backwards since that may be the orientation in which the seat is most accessible via a door of the cab  110 . Since it may be desirable to avoid accidental or unintended movement of implements during operator ingress/egress from the cab  110 , availability of the controls when the seat is neither facing forwards nor backwards may also require activation of a safety trigger. 
     While it may be convenient for use of the first and second control sticks to be dictated by default by the position of the seat assembly, it may also be desirable to allow an operator to alter the default functionality. An example of alternative functionalities is also shown in  FIG. 8 . 
     In accordance with the example alternative modes shown in  FIG. 8 , the third (hybrid) mode may be available as an alternative functionality (selected by an operator) when the seat is facing either backwards or neither forward nor backwards. The first mode may be available, for example, as an alternative functionality (selected by an operator) when the seat is facing forwards. 
     Selection of alternative functionality may be made by an operator using, for example, an alternate setting actuator, which may be a switch on a console within the cab  110 . 
       FIGS. 10 and 11  show two options for the first mode, dependent upon whether conventional backhoe style controls or conventional excavator style controls are adopted. Which of these two options is available may be fixed for a particular machine or may be selectable by an operator using some further selection mechanism.