Abstract:
Engineers have been seeking strategies to improve a work machine operator&#39;s comfort and to ensure the operator&#39;s safety. The present disclosure includes an operator control station that includes a seat assembly supported, in part, on a suspension system. At least one work machine operation controller is pivotably attached to the seat assembly between an egress position and a work machine operation position. A locking mechanism is operable to fix the work machine operation controller in the work machine operation position.

Description:
TECHNICAL FIELD  
       [0001]     The present disclosure relates generally to operator control stations for work machines, and more specifically to a method for preparing a work machine for operation via an operator control station.  
       BACKGROUND  
       [0002]     In several relatively new work machines, work machine operation controllers are attached to an operator&#39;s seat, rather than to a work machine body. By attaching the controllers to the seat, the work machine operator&#39;s comfort is improved, which in return, can improve the operator&#39;s productivity. For instance, many work machines are operated on relatively rough ground, causing vibrations that can shake the operator. A vibration path back to the operator is dampened by removing the controls from a console attached to the work machine body and mounting them on the operator&#39;s seat above a seat suspension. Moreover, European regulations limit the amount of vibration allowed to the operator.  
         [0003]     Because operators must egress to and from the operator&#39;s seat and operators are of various sizes, controllers attached to the operator&#39;s seat are preferably moveable with respect to the seat. For instance, the operator seat designed for an agricultural tractor set forth in U.S. Pat. No. 5,566,778 issued to Valier et al., on Oct. 22, 1996, includes controllers that are attached to an arm rest that is moveable in various directions. In order to provide egress to and from the operator&#39;s seat, the arm rest can be moved between a vertical and horizontal position via a friction articulated joint. In order to enhance the operator&#39;s comfort, the arm length and angle of the arm rest with the controllers can also be adjusted.  
         [0004]     Although the Valier operator seat may provide the operator with the ability to adjust the position of the work machine operation controllers in order to enhance the operator&#39;s comfort, the Valier arm rest may not be adequately robust for use in many work machines that operate under relatively rough conditions. For instance, when operating a work machine along the side of a hill, a slant of the hill will cause the operator to put the operator&#39;s weight partly on the arm rest with the controllers in order to keep himself in an upright position. Thus, the arm rest, and possibly the controllers, must be sufficiently strong to withstand a relatively large lateral load. Moreover, it is important that the operator feel secure that the arm rest will support the operator&#39;s weight. Further, because the Valier arm rest is secured into position by the friction articulated joint rather than being securely locked into a work machine operation position, the arm rest may vibrate or backlash due to the vibrations caused by rough terrain. Both the lack of strength and stiffness in the arm rest can adversely affect the operator&#39;s comfort, safety, and performance.  
         [0005]     The present disclosure is directed at overcoming one or more of the problems set forth above.  
       SUMMARY OF THE DISCLOSURE  
       [0006]     In one aspect of the present disclosure, a work machine includes a work machine body to which an operator control station with a seat assembly is attached via a suspension system. At least one work machine operation controller is pivotably attached to the seat assembly between a work machine operation position and an egress position. A locking mechanism is operable to fix the at least one work machine operation controller in the work machine operation position.  
         [0007]     In another aspect of the present disclosure, an operator control station includes a seat assembly supported, in part, on a suspension system. At least one work machine operation controller is pivotably attached to the seat assembly, and is moveable between an egress position and a work machine operation position. A locking mechanism is operable to fix the at least one work machine operation controller in the work machine operation position.  
         [0008]     In yet another aspect of the present disclosure, a work machine is prepared for operation by pivoting an arm rest including at least one work machine operation controller to a work machine operation position. The arm rest is locked in the work machine operation position. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]      FIG. 1  is a side diagrammatic view of a work machine, according to the present disclosure;  
         [0010]      FIG. 2  is a perspective diagrammatic view of an operator control station from the work machine of  FIG. 1 ;  
         [0011]      FIG. 3  is a perspective diagrammatic view of the operator control station of  FIG. 2  with an arm rest in an egress position; and  
         [0012]      FIG. 4  is a side diagrammatic view of the arm rest of  FIG. 3  locked in a work machine operation position. 
     
    
     DETAILED DESCRIPTION  
       [0013]     Referring to  FIG. 1 , there is shown a side view of a work machine  10 , according to the present disclosure. Although the work machine  10  is illustrated as a wheel loader, it should be appreciated that the present disclosure can find application in various types of work machines. The wheel loader  10  includes a work machine body  11  to which an operator control station  12  including a seat assembly  14  is attached via a suspension system  13 . The present disclosure contemplates any type of shock-absorbing suspension system known in the art that can isolate the operator from vibrations. A work machine operation controller  16  is pivotably attached to the operator control station  12 , although the present disclosure contemplates any number of work machine operation controllers being pivotably attached to the operator control station  12 . The work machine operation controller  16  is in electrical communication via a controller communication line  15  with an electronic control module  38 , which in return, is in communication with an implement, illustrated as a loader  18 , via a loader communication line  17 . Thus, an operator can control the movement of the loader  18  by manipulating the work machine operation controller  16  attached to the operator control station  12 .  
         [0014]     Referring to  FIG. 2 , there is shown a perspective view of the operator control station  12  within the work machine  10  of  FIG. 1 . The seat assembly  14  includes a seat assembly frame  39  to which a first arm rest  19 , a second arm rest  21 , a seat  20  and a back  22  are attached. The first and second arm rests  19  and  21  include cushioned housings  40 . A work machine operation controller  16  is attached to move with a portion of the first arm rest  19  between a work machine operation position  16   a  (as shown) and an egress position  16   b  (shown in  FIG. 3 ). A handle  32  is attached to the arm rest  19  in order to aid the operator in moving the arm rest  19  between the positions  16   a  and  16   b . Although the work machine operation controller  16  is preferably attached to the arm rest  19 , it should be appreciated that the work machine operation controller  16  could be pivotally attached to the seat assembly  14  at various other locations, such as to the back  22  of the seat assembly  14 .  
         [0015]     The work machine operation controller  16  is illustrated as a joystick operable to move the loader  18 . Various other work machine operation controllers, including, but not limited to, an implement lockout, a horn, a payload control system store, a throttle lock, and a throttle release, are attached to the second arm rest  21 . Although only the first arm rest  19 , and thus, work machine operation controller  16 , are illustrated as being pivotably attached to the seat assembly  14 , the present disclosure contemplates both arm rests  19  and  21 , and thus the attached work machine operation controllers, being pivotably attached to the seat assembly  14 . Both arm rests  19  and  21  are illustrated as including an adjustable arm support  24  and two arm support control knobs  23 . Each arm support  24  can be raised and lowered, and then locked into a desired height by manipulating the respective arm support control knobs  23 .  
         [0016]     Referring in addition to  FIG. 3 , there is shown a perspective view of the operator control system  12  with the arm rest  19  in the egress position  16   b . The arm rest  19  is illustrated without the cushioned housing  40  in order to illustrate an internal mechanism  30  of the arm rest  19 . The arm rest  19  includes two portions, being a moveable portion  25  and a stationary portion  26  with regard to the seat  20  of the seat assembly  14 . The stationary portion  26  can be securely attached to the seat  20  through various methods, such as bolting the stationary portion  26  to the seat assembly frame  39 . The moveable portion  25  is attached to the stationary portion  26  via pin  27 , and is constrained to pivot only about the pin  27 . Thus, the moveable portion  25  can pivot up towards the egress position  16   b  (as shown) and return downwards to the work machine operation position  16   a  (as shown in  FIGS. 2 and 4 ), but cannot pivot outwardly away from the seat  20 . The egress position  16   b  is any position out of the work machine operation position  16   a  which provides the operator with an egress path to and from the operator control station  12 . Although not illustrated in  FIG. 3 , the egress position  16   b  preferably includes a maximum egress position in which the work machine operation controller  16  is separated from the work machine operation position  16   a  by an angle greater than 90° such that arm rest  19  is roughly parallel to seat back  22 .  
         [0017]     A spring assembly  28  is operably positioned between the stationary portion  26  and the moveable portion  25 . When the arm rest  19 , and thus the work machine operation controller  16 , is in the work machine operation position  16   a , the spring assembly  28  is compressed. Preferably, the moveable portion  25  and the stationary portion  26  are castings that are comprised of heat-treated aluminum. Those skilled in the art will appreciate that the portions  25  and  26  could be made from any material that can provide sufficient strength in order to carry the load of an operator leaning on the arm rest  19  for support and provide the leaning operator with a secure feeling that the arm rest and attached controller(s) will not break or collapse. However, the material comprising the castings  25  and  26  must be light enough that it does not adversely affect, or collapse, the seat suspension  13 .  
         [0018]     Referring still to  FIG. 3 , the arm rests  19  and  21  are also preferably adjustable along a line  41  among a plurality of arm length positions. Although the present disclosure contemplates various methods of adjusting the arm rests  19  and  21  among the plurality of arm length positions, in the illustrated example, the moveable portion  25  is separated into a control section  35  and an arm support section  36 . The control section  35  can be moved backwards and forward with respect to the arm support section  36 . The work machine operation controllers, including controller  16 , are attached to the control sections  35 , and the arm supports  24  are attached to the arm support sections  36 . In the illustrated example, two moveable shafts  37  extend between the arm support section  36  and the control section  35 . The shafts  37  slide within bores defined by the arm support section  36 . The control section  35  is operably coupled to move with the sliding shafts  37 . At least one of the shafts  37  define arm position bores (not shown) separated by a predetermined distance. Each arm position bore correlates to a different arm length position. Although the predetermined distance between the arm position bores can vary, the predetermined distance is a distance which can provide a sufficient number of discrete arm length positions to accommodate operators of various arm lengths. In the illustrated example, the predetermined distance is one half of an inch. A spring loaded pin (not shown) is moveable in and out of the arm position bores. When the spring loaded pin is in a first position and aligned with one of the arm position bores, the spring loaded pin extends into one of the arm position bores. An arm length position release (not shown) is operable to move the spring loaded pin into the second position so the operator can adjust the distance between the control section  35  and the support section  36 . When the spring loaded pin is unaligned with the arm position bores, the spring loaded pin is in pushed into the second position against the bias of the spring by the shaft body.  
         [0019]     Referring to  FIG. 4 , there is shown a side view of the arm rest  19  in the work machine operation position  16   b . Similar to  FIG. 3 , the cushioned housing  40  is removed to illustrate the internal mechanism  30  of the arm rest  19 . The seat assembly  14  includes a locking mechanism  33  that is operable to fix the work machine operation controller  16  in the work machine operation position  16   a . The locking mechanism  33  includes a spring loaded rod (not shown) running through the moveable portion  25  When the arm rest  19  is in the work machine operation position  16   a  (as shown), the rod is biased into a first position and aligned with a rod bore (not shown) within the stationary portion  26 . In the first position, the rod extends between the moveable portion  25  and into the rod bore of the stationary portion  26 . The locking mechanism  33  also includes an operator lock release  34  (shown in  FIG. 3 ) that is operable to move the spring loaded rod to a second position in which the rod does not extend into the rod bore. When the work machine operation controller  16  is out of the work machine operation position  16   a , the spring loaded rod remains in the second position and is out of alignment with the rod bore.  
         [0020]     In order to move the arm rest  19  out of the work machine operation position  16   a , a lever  29  that is moveable between an inoperable and an operable position (as shown) is in the inoperable position. The lever  29  is operably coupled to a switch  31 . When the lever  29  is in the operable position, the switch  31  permits electrical communication between the electronic control module and the controller  16 . However, when the lever  29  is in the inoperable position, the switch disables the controller  16  by breaking communication between the electronic control module  38  and the controller  16 . Thus, when the arm rest  19 , and thus, the attached work machine operation controller  16 , is not in the work machine operation position  16   a , the work machine operation controller  16  is inoperable. Those skilled in the art will appreciate that there are various other methods of making the controller  16  inoperable, including, but not limited to, programming the electronic control module to de-activate the controller when it receives a signal indicating that the arm rest is in the egress position.  
       INDUSTRIAL APPLICABILITY  
       [0021]     Referring to  FIGS. 1-4 , a method of preparing the wheel loader  10  for operation will be discussed. Although the operation of the present disclosure will be discussed for the operator control station  12  within the illustrated wheel loader  10 , the present disclosure operates similarly for an operator control station in any work machine. In order to egress to and from the operator control station  12 , the operator can move the arm rest  19 , and thus the work machine operation controller  16 , to the egress position  16   b  (shown in  FIG. 3 ). In order to move the arm rest  19  to the egress position  16   b , the operator must first move the lever  29  to the inoperable position in which the switch  31  coupled to the lever  29  breaks the communication between the electronic control module  38  and the controller  16 . Because the work machine operation controller  16  is inoperable, if the operator were to accidentally move the controller  16  by slipping and falling during egress to and from the operator control station  12 , the operator would not activate the wheel loader  10 . Moreover, those skilled in the art will appreciate that the controller  16  is designed such that the weight of a falling operator on the controller  16  should not disable the controller  16 . After the controller  16  is inoperable, the operator can pull on the operator lock release in order to move the spring loaded rod (not shown) to the second position, which is out of the rod bore. When the spring loaded rod is in the second position, the operator can use the handle  32  to lift the arm rest  19  out of the work machine operation position  16   a . The spring loaded rod will remain out of position with the rod bore and in the second position while the work machine operation controller  16  is out of the work machine operation position  16   a.    
         [0022]     When the arm rest  19  is in the egress position  16   b , there is room for the operator to access the operator control station  12  without making contact with the work machine controller  16 , thereby increasing the operator&#39;s comfort and safety. Moreover, the operator can move the arm rest  19 , and the work machine operation controller  16 , to the maximum egress position which is greater than 90° from the work machine operation position  16   a . Thus, if the spring assembly  28  were to break while the work machine operation controller  16  was in the maximum egress position, gravity will help prevent the arm rest  19  and controller  16  from falling toward the work machine operation position  16   a.    
         [0023]     Once the operator is seated in the seat assembly  13 , the operator can use the handle  32  to move the arm rest  19 , and thus the work machine operation controller  16 , to the work machine operation position  16   a . The arm rest  19  including the work machine operation controller  16  will pivot about the pin  27  to the work machine operation position  16   a . When the arm rest  19  is in the work machine operation position  16   a , the spring loaded rod of the locking mechanism  33  will align with the rod bore within the stationary portion  26  of the arm rest  19 . When aligned, the spring loaded rod will extend between the stationary portion  26  and the moveable portion  25  of the arm rest  19 , thereby securing the arm rest  19  in to the work machine operation position  16   a . Because the arm rest  19  and work machine operation controller  16  are locked into the work machine operation position  16   a  by the locking mechanism  33 , any backlash or movement between the arm rest  19  and the seat  20  during the operation of the wheel loader  10  is reduced, if not eliminated.  
         [0024]     Once the operator has positioned himself within the operator control station  12  and has locked the arm rest  19  into the work machine operation position  16   a , the operator can preferably adjust the work machine operation controller  16  to the operator&#39;s desired arm length position. The operator can move the control section  35  of the arm rest  19  relative to the seat  20  and the arm support section  36  to the desired arm length position. Although there are various methods of adjusting the control section  35  forwards and backwards, in the illustrated example, the operator can pull on the controller position lock release (not shown) that will move the spring loaded pin from one of the arm position bores within one of the shafts  37 , allowing the operator to pull the control section  35  coupled to move with the shafts  37  forward and backwards. Once the control section  35  is at the operator&#39;s arm length position, the operator can release the controller position lock release. The pin will reinsert itself within one of the arm bores in order to lock the control section  35  at the desired arm length position. Further, preferably the operator can adjust the height of the arm support  24  by manipulating the arm support  24  and the arm support control knobs  23 . The operator can make similar adjustments to the control section  35  and arm support  24  of the arm rest  21 .  
         [0025]     Once the operator control station  12  is adjusted for the particular size of the operator, the operator can begin work machine operation. During operation, the wheel loader  10  may operate over rough terrain. Because the work machine operation controller  16  is attached to the seat assembly  13  above the seat suspension  13 , a vibration path to the operator through the work machine operation controller  16  is reduced, or even eliminated. Moreover, because the arm rest  19  is locked into the work machine operation position  16   a , the arm rest  19  will not move relative to the seat  20  due to the rough terrain. In addition, the operator may be required to operate the wheel loader  10  at an angle, such as on the side of a hill. Because the moveable and stationary portions  25  and  26  are castings made from heat-treated aluminum, the arm rests  19  and  21  are sufficiently strong to withstand the lateral load of the operator and provide the leaning operator with a secure feeling. However, the castings are light enough that they do not place excessive weight on the seat suspension  13 .  
         [0026]     The operator control station  12  of the present disclosure is advantageous because it provides operator safety and comfort, that in return, provides increased operator productivity. The present disclosure provides the operator with the ability to adjust the operator control station  12  to fit his or her size while also limiting the undesirable movement of the seat assembly  14 . In order to isolate the operator from vibrations caused by the operation of the wheel loader  10 , the work machine operation controllers are attached to the arm rests  19  and  21 , and the seat suspension  13  is operably positioned between the arm rests  19  and  21  and the work machine body  11 . In order to reduce the movement or back lash of the arm rest  19  relative to the seat  20  of the seat assembly  14  during operation of the wheel loader  10 , the pivoting action of the moveable portion  25  is limited between the work machine operation position  16   a  and the egress position  16   b , and the arm rest  19  locks into the work machine operation position  16   a . In order to ensure the operator&#39;s safety while leaning on the arm rests  19  and  21  for support during operation of the wheel loader  10  at an angle, the present disclosure includes sturdy arm rests  19  and  21  made from heat-treated aluminum castings.  
         [0027]     The present disclosure also provides the operator with the ability to adjust the operator control station  12  to fit his or her size. The operator can adjust the arm rest  19  and  21  so that the work machine controllers, including controller  16 , are located at the arm length position corresponding to the operator&#39;s arm length. Further, the operator can adjust the height of the arm supports  24 , and pivot the moveable portion  25  of the arm rest  19  up and down in order to provide a path for egress to and from the operator control station  12 . Although the present disclosure illustrates only arm rest  19  being moveable about the pin  27 , the present disclosure contemplates both arm rests being moveable between the work machine operation position  16   a  and the egress position  16   b.    
         [0028]     It should be understood that the above description is intended for illustrative purposes only, and is not intended to limit the scope of the present disclosure in any way. Thus, those skilled in the art will appreciate that other aspects, objects, and advantages of the disclosure can be obtained from a study of the drawings, the disclosure and the appended claims.