Patent Publication Number: US-2023151582-A1

Title: Apparatus for facilitating bucket movement

Description:
BACKGROUND 
     Industrial and construction machines such as skid steer loaders, compact wheel loaders, and mini-excavators include a bucket implement. The bucket implement is used to pick up various materials, which may become lodged in the bucket. In order to dislodge the stuck material, an operator can perform a “bucket shake” operation by moving the joystick back and forth quickly between “dump” and “curl” positions to quickly shake the bucket. 
     SUMMARY 
     The present disclosure relates to an apparatus for facilitating bucket movement of a material handling machine. The apparatus includes a first operator input movable between a neutral position, a first position and a second position. The apparatus further includes a second operator input actuatable from a disengaged position to an engaged position, the first operator input operable in a first mode of operation when the second operator input is in the disengaged position and operable in a second mode of operation when the second operator input is in the engaged position. In the first mode of operation, the first operator input is configured to curl a bucket of the apparatus when displaced from the neutral position toward the first position and is configured to dump the bucket of the apparatus when displaced from neutral position toward the second position. In the second mode of operation, the bucket is configured to move in an oscillatory motion and an intensity of the oscillatory motion is dependent upon a position of the first operator input. The intensity of the oscillatory motion is a first intensity when the first operator input is in the neutral position. The intensity of the oscillatory motion is increased relative to the first intensity to a second intensity at the first position. The intensity of the oscillatory motion is decreased relative to the first intensity to a third intensity at the second position. 
     The present disclosure relates further to an apparatus for facilitating bucket movement of a material handling machine. The apparatus includes a joystick biased to a neutral position and movable from the neutral position to a maximum dump position and a maximum curl position. The apparatus further includes an operator input movable between a disengaged position and an engaged position. A bucket of the material handling machine is configured to automatically move in an oscillatory motion when the operator input is in the engaged position, regardless of a position of the joystick. An intensity of the oscillation is dependent upon the position of the joystick, a maximum intensity corresponding to the joystick in one of the maximum dump position or the maximum curl position, and a minimum intensity corresponding to the joystick in the other one of the maximum dump position or the maximum curl position. 
     The present disclosure further relates to an apparatus for facilitating bucket movement of a material handling machine, the apparatus includes a joystick biased to a neutral position, movable away from the neutral position in a first direction along an axis to a first position, and movable away from the neutral position in a second direction along the axis, opposite the first direction, to a second position. The apparatus further includes an operator input movable from a disengaged position to an engaged position in which a bucket of the material handling machine is configured to automatically move in an oscillatory motion. When the operator input is in the engaged position, an intensity of the oscillation is dependent upon a position of the joystick along the axis, decreasing along the axis from the first position to the second position. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a representation of an operator input for controlling operation of a material handling machine. 
         FIG.  2    is a schematic representation of a hydraulic system and an associated bucket of the material handling machine. 
         FIG.  3    is a flowchart detailing a bucket shake operation. 
     
    
    
     DETAILED DESCRIPTION 
     Before any embodiments are explained in detail, it is to be understood that the disclosure is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The disclosure is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. The terms “mounted,” “connected” and “coupled” are used broadly and encompass both direct and indirect mounting, connecting and coupling. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings, and can include electrical connections or couplings, whether direct or indirect. 
       FIG.  1    illustrates an example of a first operator input, shown as a joystick  10  that includes a joystick handle  12  and a base  16 . In various systems, for example, a material handling machine  18  such as a front-loader vehicle (e.g., skid steer loader, compact track loader, mini-excavator, wheel loader, compact wheel loader, backhoe loader), the joystick handle  12  is manipulated to move relative to the base  16  to control the movement and operation of the system. Moving the joystick  10  may involve rotating or pivoting the joystick about a point of rotation defined within the base such that a distal end of the joystick handle  12  moves relative to the base  16 . The joystick  10  outputs a position signal indicative of the position of the handle  12  relative to the base  16 . This position signal typically defines the current displacement of the joystick handle  12  from a home origin position in either Cartesian or radial coordinates. Although the examples described below refer primarily to Cartesian coordinates (i.e., (x, y)), various aspects of the system can be adapted to function with radial coordinate systems. 
     The joystick  10  controls operation of a bucket  14  of a material handling machine  18  (see  FIG.  2   ). The bucket  14  is hydraulically coupled to a boom or lift arm  22  and is rotatable relative to the lift arm  22  to facilitate digging, lifting, carrying, and dumping material such as dirt, gravel, and debris. The bucket  14  rotates in a first direction B 1  to curl the bucket  14  in a curl operation. The bucket  14  rotates in a second direction B 2  to dump the bucket  14  in a dump operation. 
     The handle  12  of the joystick  10  is a user-engageable handle that is movable from a neutral position (as shown in  FIG.  1   ) to a plurality of different positions that control a hydraulic aspect of the material handling machine  18 . The neutral position is a central position, and the joystick  10  is biased to the neutral position. The joystick  10  is movable from the neutral position along at least a linear path defined as a first axis A and, in some embodiments, along a second linear path defining a second axis as well. When the joystick  10  is moved from the neutral position in a first direction D 1  along the first axis A, the bucket  14  of the material handling machine  18  moves in the first, curl direction B 1  toward a curl position. When the joystick  10  is moved from the neutral position in a second direction D 2 , opposite the first direction D 1 , along the first axis A, the bucket  14  moves in the second, dump direction B 2  toward a dump position. The joystick  10  is therefore movable along the linear path defining the first axis A from one position, through the neutral position, and to another position. The joystick  10  may further be movable along a second axis to control other aspects of the material handling machine  18  (e.g., raising/lowering the lift arm  22 , operating the boom, moving or rotating the machine  18 ). The joystick  10  may be moved to locations other than along the first and second axes, such as positions that include displacement from the neutral position along both axes simultaneously. In such positions, the joystick  10  is considered to have moved along the first axis A despite the motion not being purely along the first axis A. 
       FIG.  2    illustrates an example of a hydraulic schematic of a system configured to convert the operator input at the joystick  10  into movement of the bucket  14 . A hydraulically controlled pump  26 , such as a purely hydraulic controlled pump or a pump with an active swash plate control, receives feedback from a load sensing line  30 . Hydraulic cylinders  34 A,  34 B associated with the bucket  14  are controlled by an electrohydraulic proportional valve  38  with a pre-compensator  46 . A controller  100  receives inputs (signals) from the joystick  10  and provides outputs (signals) to control the proportional valve  38  and/or the pump  26  based on the inputs. While the proportional valves  38  are shown as two-position valves, three-position valves (e.g., having a float position) or valves having more than three positions are also contemplated. In some embodiments, the pilot pressure is provided externally by a charge pump  42 . In other embodiments, the pilot pressure can be generated internally by the valve  38 . Further, in some embodiments, the load sensing line  30  may be omitted, relying instead on a pressure sensor for identifying the load. An inlet section  50  of the hydraulic system controls fluid pressure and may include components that assist in controlling the pump  26 . The inlet section  50  is only one example of an inlet section that may be utilized. The schematic further illustrates the valve arrangements for two additional implements (in addition to the bucket  14 ; e.g., a boom, auxiliary hydraulics), though the respective cylinders are omitted. 
     In a primary mode of operation, the operator actuates the handle  12  of the joystick  10  from the neutral position towards either the curl position or the dump position. The pump  26  and proportional valve  38  are controlled based on the position of the joystick  10  along the axis to provide fluid to the hydraulic cylinders  34 A,  34 B, thereby rotating the bucket  14  in the desired direction, curling or dumping the bucket  14 . The rotational velocity of the bucket  14  is controlled by the displacement of the joystick  10  from the neutral position, with higher velocity being associated with greater displacement. Rotational velocity of the bucket  14  is related to the volumetric flow rate to the cylinders  34 A,  34 B, with other factors (e.g., load within the bucket) also effecting the velocity. As such, when the joystick is displaced greater distances, the pump  26  and proportional valve  38  are electro-hydraulically controlled to provide more fluid to the cylinders  34 A,  34 B. 
     In some scenarios, such as when an item is lodged or otherwise stuck within the bucket  14 , an operator conducts a bucket shake operation to quickly oscillate the bucket  14  in an attempt to dislodge the material from within the bucket. A manual bucket shake operation therefore involves oscillating the joystick  10  back and forth between the curl and dump positions to quickly shake the bucket  14 . An automated bucket shake operation involves a separate user input to quickly shake the bucket  14  without manually oscillating the joystick  10 . 
     The material handling machine  18  includes a second user input, a button  54  that is a momentary switch movable between an engaged position and a disengaged position. In the disengaged position, the joystick  10  operates in the primary mode of operation. In the engaged position, the automated bucket shake operation is operated and the functionality of the joystick  10  is modified to operate in a secondary, bucket shake mode of operation. As shown, the button  54  is located on the joystick  10 , thereby allowing an operator to engage both of the joystick  10  and the button  54  simultaneously with a single hand. In other embodiments, the button  54  may be located elsewhere within reach of the operator. The button  54  is biased to the disengaged position and is held (by the operator) in the engaged position by depressing the button  54 . When the operator removes pressure from the button  54 , it returns to the disengaged position. In some embodiments, the button  54  is replaced by an alternative input such as a switch, a push-push button, or a capacitive or other touch interface. 
     When the button  54  is depressed, the controller  100  receives a signal to operate the machine  18  in a second mode of operation that conducts an automated bucket shake operation. The controller  100  is therefore programmed to receive a first signal from the joystick  10  corresponding to a position of the joystick  10 , and is also programmed to receive a second signal from the button  54  corresponding to a status (engaged, disengaged) of the button  54 . The controller  100  is also programmed to control the pump  26  and/or the valve assembly  38  to move the bucket  14  based on the first and second signals. The bucket shake operation begins automatically by depressing the button  54  (such that the button is in the engaged position) regardless of the position of the joystick  10 . As such, the bucket shake operation occurs when the joystick  10  is in the neutral position and the button  54  is in the engaged position. The bucket shake operation likewise occurs when the joystick  10  is displaced from the neutral position (i.e., along the first axis A) and the button  54  is in the engaged position. When the operator removes pressure from the button  54 , the button  54  returns to the biased disengaged position. 
     Movement of the joystick  10  in the secondary (automated bucket shake) mode of operation produces a different output than the same movement in the primary mode of operation. When in the second mode of operation, the bucket  14  is oscillating quickly between dump and curl positions, and therefore moving the joystick  10  toward the dump position or the curl position does not rotate the bucket in this direction (beyond the oscillating motion). Rather, movement of the joystick  10  along the first axis A, while in the secondary mode of operation, modifies the intensity of the bucket shake operation. Modifying the intensity may include modifying one or more of speed, acceleration, jerk (rate of change of acceleration), or range of motion. Written another way, the peaks of the oscillations within the bucket shake operation may be modified to be closer together/further apart, sharper/smoother, and/or higher/lower. 
     In one embodiment, as described in greater detail below, in the secondary mode of operation, moving the joystick  10  from the neutral position toward the dump position (i.e., in the direction D 2 ) increases the intensity of the bucket shake operation (i.e., the intensity of the oscillatory motion) and moving the joystick  10  from the neutral position toward the curl position (i.e., in the direction D 1 ) decreases the intensity. In another embodiment, the curl position may be associated with increased intensity and the dump position is associated with decreased intensity. The distance that the joystick  10  is displaced from the neutral position may correspond to the change in intensity (e.g., proportionally). The intensity when the joystick  10  is at the neutral position is a first intensity. When the joystick is moved toward the dump position, the intensity increases from the first intensity to a second, maximum, intensity at the dump limit (maximum displacement along the first axis A in the dump direction) of the joystick  10 . Other intensities between the first and second intensities are achievable at joystick positions between the neutral position and the dump limit. Similarly, when the joystick  10  is moved toward the curl position, the intensity decreases from the first intensity to a third, minimum intensity at the curl limit (maximum displacement along the first axis A in the curl direction) of the joystick  10 . Other intensities between the first and third intensities are achievable at joystick positions between the neutral position and the curl limit. If the joystick  10  is movable along the second axis, such movement does not have a bearing on the intensity of the bucket shake operation. 
     The intensity of the oscillating motion of the bucket shake operation can be modified by adjusting parameters of the pump  26 . For a purely hydraulically controlled pump  26 , bucket shake is achieved by switching between dump and curl positions with the following adjustable parameters: minimum dump current, maximum dump current, dump period, minimum curl current, maximum curl current, and curl period. If the pump  26  has a controllable swash plate, displacement dump and displacement curl are two additional parameters of the bucket shake algorithm that will aid in defining frequency and amplitude of the oscillating motion of the bucket shake operation. A predefined combination of these parameters is set as a predefined, default shake condition that corresponds to the neutral position of the joystick  10 . 
     The joystick  10  may have a dead zone  60  along the first axis A directly adjacent to the neutral position. The dead zone  60  is limited to small movements from the neutral position. In the dead zone  60 , movement of the joystick  10  does not result in a registered input. As such, in the secondary mode of operation, movement of the joystick  10  within the dead zone  60  does not result in a modification of the intensity of bucket shake operation. The intensity therefore monotonically increases (i.e., does not decrease) from a minimum intensity at one of the extreme positions along the axis A, leveling out at the dead zone  60 , and increasing from the dead zone  60  to a maximum intensity at the other extreme position along the axis A. 
     In operation and with reference to  FIG.  3   , if the operator identifies that material is stuck within the bucket  14 , the operator depresses the button  54  (step  110 ), thereby initiating the bucket shake operation (step  120 ). The pump  26  and proportional valve  38  are actuated by the controller  100  to alternate which chamber of the two hydraulic cylinders  34 A,  34 B associated with the bucket  14  receives the volumetric flow to move the bucket  14  in an oscillating motion in an attempt to dislodge the material from the bucket  14  (step  130 ). The controller  100  monitors the position of the joystick  10  (step  140 ). If the joystick  10  is in the neutral position, the bucket shake operation will operate with a predefined intensity (i.e., speed, acceleration, jerk, and/or magnitude) (step  150 ). If the operator decides that the bucket shake operation is too intense or wants a smoother, more subtle bucket shake operation (e.g., attempting to slowly shake out the contents of the bucket  14 ), the operator moves the joystick  10  along the first axis A toward the curl position (i.e., in the direction D 1 ), holding the joystick  10  at a position that corresponds to the desired intensity. If the operator decides that the bucket shake operation is too subtle or wants a more intense bucket shake operation (e.g., if the predefined intensity is insufficient to dislodge the material), the operator moves the joystick  10  along the first axis A toward the dump position (i.e., in the direction D 2 ), holding the joystick  10  at a position that corresponds to the desired intensity. The joystick  10  can be moved from the neutral position while in the bucket shake operation (e.g., after identifying that the predefined intensity is undesirable) or prior to initiating the bucket shake operation (e.g., if the operator is aware based on prior experience that the desired bucket shake operation differs from the predefined bucket shake operation) (step  160 ). When the material is dislodged from the bucket  14 , the operator releases the button  54 , returning it to the disengaged position, and returns the joystick  10  to the neutral position. Similarly, if the button  54  is not depressed, the system operates in the primary mode of operation (step  170 ). 
     Although some aspects have been described in detail with reference to certain preferred embodiments, variations and modifications exist within the scope and spirit of one or more independent aspects as described. Various features and advantages of the invention are set forth in the following claims.