PATENT ABSTRACT
An adjustable control pedestal for a work machine. The control pedestal may include a base configured to be rigidly mounted to a chassis of the work machine. The control pedestal may also include an armrest portion having a joystick mounted thereto configured to control at least one function of the work machine, the armrest portion being connected to the base and configured to enable an operator to rest an arm on the armrest portion while operating the joystick. The armrest portion may be linearly movable relative to the base.

PATENT DESCRIPTION
TECHNICAL FIELD  
       [0001]     This disclosure is directed to a control pedestal for a work machine and, more particularly, to an adjustable floor-mounted control pedestal for controlling functions of a work machine.  
       BACKGROUND  
       [0002]     Whether driving off-road or operating a work implement, an operator of a work machine may be subjected to sudden and/or severe movements during the normal course of machine operation. Such movements may include, for example, a bumpy ride during off-road driving or various jarring impacts from engagement of a work implement with a work surface.  
         [0003]     Seating systems have been developed to insulate the operator from these sudden and/or severe movements in order to help operators maintain a seating position suitable for operating the machine. In particular, operator seats are commonly provided with suspension to somewhat isolate the operator from movements of the work machine chassis.  
         [0004]     In addition to maintaining a suitable seating position, an operator may be required to make minute control inputs to accurately control functions of a work machine. These minute control inputs are more easily made if an operator can maintain a steady hand. To help operators maintain a steady hand, armrest control consoles have been used to support the hand and arm of an operator.  
         [0005]     Armrest control consoles have been mounted to operator seats in order to maintain a positional relationship between the control console and the seat despite adjustment and/or movement of the seat. In addition, control consoles have been mounted to suspended seats in order to insulate the controls from sudden and/or severe movements of the work machine chassis. Control consoles have also been provided with adjustability to enable operators of various sizes to create a comfortable and supportive seating position. Further, controls for work machines have been consolidated so as to provide multiple controls with a single lever, commonly called a “joystick.” For example, U.S. Pat. No. 4,702,520 (the &#39;520 patent) to Whisler et al. discloses an adjustable armrest control console having a joystick mounted thereto. The &#39;520 patent further teaches that the console is attached to the operator seat.  
         [0006]     However, while the console of the &#39;520 patent may provide support and stability for an operator&#39;s arm by being mounted to the seat, it may also isolate the operator from tactile feedback that may enhance their ability to control the work machine. Suspending controls rather than rigidly attaching them to a work machine chassis may eliminate or significantly reduce tactile feedback through the controls that may enable an operator to better sense the movements of the work machine. Without having this kind of sensory information to take into account, an operator may not be able to control the functions of the work machine as accurately. Also, the &#39;520 patent teaches only limited adjustability of the console. The overall height of the console is not adjustable, nor may the console be adjusted fore and aft or rotated side-to-side.  
         [0007]     The disclosed control pedestal is directed towards overcoming one or more of the problems set forth above.  
       SUMMARY OF THE INVENTION  
       [0008]     In one aspect, the present disclosure is directed to an adjustable control pedestal for a work machine. The control pedestal may include a base configured to be rigidly mounted to a chassis of the work machine. The control pedestal may also include an armrest portion having a joystick mounted thereto configured to control at least one function of the work machine, the armrest portion being connected to the base and configured to enable an operator to rest an arm on the armrest portion while operating the joystick. The armrest portion may be linearly movable relative to the base.  
         [0009]     In another aspect, the present disclosure is directed to a work machine. The work machine may include an operator station. The operator station may include a floor, an operator seat suspended on the floor, and a control pedestal. The control pedestal may include a base mounted on a chassis of the work machine, and an armrest portion connected to the base and having a joystick mounted thereon configured to control one or more functions of the work machine.  
         [0010]     In another aspect, the present disclosure is directed to a motor grader. The motor grader may include a traction system, a power source, and a work implement. The motor grader may further include an operator station having a floor, an operator seat suspended on the floor, and a control pedestal. The control pedestal may include a base rigidly mounted to a chassis of the motor grader and an armrest portion connected to the base and having a joystick mounted thereon configured to control one or more functions of the motor grader. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]      FIG. 1  is a diagrammatic illustration of a work machine according to an exemplary disclosed embodiment;  
         [0012]      FIG. 2  is a diagrammatic perspective view of a control pedestal according to an exemplary disclosed embodiment;  
         [0013]      FIG. 3  is a diagrammatic side view of the control pedestal of  FIG. 2 ;  
         [0014]      FIG. 4  is another diagrammatic perspective view of the control pedestal of  FIG. 2 ; and  
         [0015]      FIG. 5  is a diagrammatic perspective view of a framework of the control pedestal of  FIG. 2 .  
     
    
     DETAILED DESCRIPTION  
       [0016]     Reference will now be made in detail to the drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.  
         [0017]      FIG. 1  illustrates an exemplary embodiment of a work machine  10 . Although work machine  10  is shown as a motor grader, work machine  10  may include other types of work machines such as, for example, track-type tractors (e.g. bulldozers), wheeled tractors, loaders, excavators, and any other type of work machine. Work machine  10  may include a work implement  12 , an operator station  14 , a power source  16 , and one or more traction devices  18 .  
         [0018]     Work implement  12  may include a blade  20  as shown in  FIG. 1 . Alternatively, work implement  12  could include a bucket, scraper, claw, or any other type of work implement.  
         [0019]     Although traction devices  18  are shown in the figures as wheels, traction devices  18  could alternatively be tracks or any other type of traction devices. Traction devices  18  could also be combinations of different types of traction devices. For example, work machine  10  could include both wheels and tracks.  
         [0020]     Operator station  14  may reside in an enclosed cab, as shown in  FIG. 1 . Alternatively, operator station  14  could be open-topped or covered but otherwise open.  FIG. 1  shows a cutaway portion revealing an interior layout of operator station  14 , which may include an operator seat  22 , a control pedestal  24  mounted to a floor  26  of operator station  14 , and additional controls such as a steering wheel  28  and one or more foot pedals  30 .  
         [0021]     Operator seat  22  may be a suspended seat. That is, in addition to having conventional seat cushion material and/or springs within the cushion to soften the ride, operator seat  22  may be attached to floor  26  by a suspension system  31 . Suspension system  31  may be of any design to attenuate transmission of sudden and/or severe movements of work machine  10  to operator seat  22 . For example, suspension system  31  may include a set of coil springs or air springs (not shown). Suspension system  31  may also include one or more damping devices, such as, for example, shock absorbers.  
         [0022]     Control pedestal  24  may be positioned anywhere on work machine  10  suitable for use by an operator. Operator station  14  may include more than one control pedestal  24 , for example, work machine  10  may be provided with two control pedestals  24 , one for each side of operator seat  22 . Control pedestal  24  may be rigidly mounted to floor  26  or any other component of the chassis of work machine  10 . Control pedestal  24  may include a joystick  32  configured to control one or more functions of work machine  10 .  
         [0023]     Operator station  14  may include additional controls, such as steering wheel  28  and foot pedal  30 . Operator station  14  may also include other types of additional controls, such as additional levers or joysticks, dials, and/or switches. The additional controls may control different functions of work machine  10  than does joystick  32 . The additional controls may also control one or more of the same functions as does joystick  32 . For example, both joystick  32  and steering wheel  28  may be configured to steer work machine  10 . Duplicate controls for the same function may be provided for safety reasons (i.e., a backup system) or simply to offer an operator an option to choose the control that is more comfortable to them.  
         [0024]      FIG. 2  illustrates an exemplary embodiment of control pedestal  24 . Control pedestal  24  may include joystick  32 , a base  46 , and an armrest portion  56 .  
         [0025]     Joystick  32  may be any type of control lever and may control a single function or multiple functions. For example, each movement of joystick  32  may control a different function of work machine  10 . Exemplary movements of joystick  32  may include fore and aft motion, as indicated by a double-headed arrow  34 , side-to-side motion, as indicated by a double-headed arrow  36 , and rotational motion about an axis  38 , as indicated by a double-headed arrow  40 . Other functions may be controlled from joystick  32  with buttons and switches on joystick  32 , such as a push-button  42  and a trigger  44 . Possible functions that may be controlled by these different motions, buttons, and switches may include movements of work implement  12  ( FIG. 1 ), steering of work machine  10 , throttle, braking, and any other movements or functions of work machine components.  
         [0026]     Base  46  may include a base plate  48 , which may be fixedly attached, in any conventional manner (e.g., bolts, welds, clamps, etc.) to floor  26  or another part of the chassis of work machine  10 . Base  46  may also include a post  50 . Post  50  may be height adjustable, for example, by telescoping an upper portion  52  within a lower portion  54 . Base  46  may also permit rotation of armrest portion  56  in a direction indicated by double-headed arrow  55 . In order to permit this rotation, upper portion  52  may be rotatable relative to lower portion  54 . Alternatively a bearing or other rotatable component mounted to or incorporated in base  46  may enable rotation of armrest portion  56  relative to floor  26 . Rotation of armrest portion  56  may facilitate ingress and egress from operator seat  22  and enable an operator to orient armrest portion  56  at a comfortable angle.  
         [0027]     Armrest portion  56  may be supported by base  46 . Accordingly, the height of armrest portion  56  may be adjusted by adjusting the height of post  50 . Additionally, armrest portion  56  may slide fore and aft with respect to base  46  as indicated by a dashed outline  58  and corresponding movement arrow  59 . This sliding movement may facilitate ingress and egress from operator seat  22  and enable an operator to position armrest portion  56  at a comfortable position during operation of work machine  10 . Joystick  32  may be mounted on armrest portion  56 . Therefore, sliding of armrest portion  56  fore and aft may enable the operator to position joystick  32  such that it may be comfortably grasped during use.  
         [0028]     Control pedestal  24  may also include an arm support  60 , which may be attached to armrest portion  56 . The position of arm support  60  relative to armrest portion  56  may be adjustable. The position of arm support  60  may be adjusted by loosening a knob  62  that may otherwise hold arm support  60  in a fixed position relative to armrest portion  56 . When knob  62  has been loosened, arm support  60  may be freely adjusted for height and incline.  
         [0029]      FIG. 3  illustrates the adjustability of arm support  60 . Because arm support  60  may be fixed relative to armrest portion  56 , arm support  60  may move with armrest portion  56  when it slides fore and aft, as shown by a dashed outline  64  and corresponding movement arrow  65 . Arm support  60  may also be adjusted for height as indicated by dashed outline  66 . In addition, the incline of arm support  60  may be adjusted by tilting arm support  60  forward, as indicated by an arrow  68 , or rearward, as indicated by an arrow  70 .  
         [0030]      FIG. 4  illustrates the inner framework and components of armrest portion  56 . The framework of armrest portion  56  may include three brackets to which its outer panels are attached. A front bracket  72  and a rear bracket  74  may be joined by an upper bracket  76  and one or more rods  78 . Joystick  32  may be mounted to front bracket  72 .  
         [0031]     Armrest portion  56  may further include a lower bracket  80 , which may be fixedly attached to base  46 . A slide housing  82  may be fixedly attached to lower bracket  80 . Rods  78  may pass through slide housing  82 , which may include low friction components such as bearings or bushings to enable rods  78  to slide back and forth through slide housing  82 . Because front bracket  72 , rear bracket  74 , and upper bracket  76  are fixedly attached to rods  78 , these components also slide back and forth relative to slide housing  82 , lower bracket  80 , and base  46 .  
         [0032]     In addition,  FIG. 4  illustrates the mechanism by which arm support  60  may be adjusted. Arm support  60  may include downwardly extending side plates  84  extending down on both sides of upper bracket  76 . Side plates  84  may include slots  86 . Slots  86  may receive a threaded bolt (not shown) attached to knob  62 . By tightening knob  62  (e.g., by turning), clamping members  88  may be pressed against the outer sides of side plates  84 , thereby clamping them against upper bracket  76  and preventing them from moving relative to upper bracket  76 .  
         [0033]     In use, an operator may loosen knob  62  to allow arm support  60  to move freely with respect to upper bracket  76 . The operator may then adjust the height and incline of arm support  60 . When the operator achieves the desired position of arm support  60 , it may be fixed in that position by tightening knob  62 .  
         [0034]      FIG. 5  illustrates the inner framework and components of armrest portion  56  with joystick  32 , arm support  60 , knob  62 , and upper bracket  76  removed, exposing the mechanism by which armrest portion  56  may be slidably adjusted. In order to set armrest portion  56  at different positions along its sliding range of movement, armrest portion  56  may include a latch rod  90  rotatably attached to upper bracket  76  and front bracket  72  at a first end  92  and to upper bracket  76  and rear bracket  74  at a second end  94 . First end  92  and second end  94  of latch rod  90  may include bushings, bearings, or any other rotatable coupling to enable rotation of latch rod  90  relative to front bracket  72 , rear bracket  74 , and upper bracket  76 .  
         [0035]     Latch rod  90  may further include a latch bracket  96 , which may latch onto teeth  98  of a toothed flange  100 . Toothed flange  100  may be mounted to the top of slide housing  82 . Thus, when latch bracket  96  is latched onto teeth  98 , latch rod  90 , front bracket  72 , rear bracket  74 , upper bracket  76 , and rods  78  are fixed relative to base  46 . Latch rod  90  may also include a handle  102  laterally protruding from latch rod  90  and extending out through the outer side paneling of armrest portion  56 . (See  FIG. 2 .) By lifting handle  102 , latch rod  90  may be rotated, thereby unlatching latch bracket  96  from teeth  98 , and thus, allowing latch rod  90 , front bracket  72 , rear bracket  74 , upper bracket  76 , and rods  78  to slide forward and backward relative to base  46 .  
         [0036]     Although an exemplary embodiment has been described with regard to the mechanisms that allow adjustability of control pedestal  24 , one of ordinary skill in the art may recognize alternative mechanisms to achieve the same or similar adjustability. The components of control pedestal  24  may be made from any materials of suitable strength and properties. Base  46  as well as the framework of armrest portion  56  may be made of materials rigid enough to transmit vibrations from floor  26  to joystick  32  to provide tactile feedback to an operator. Such materials may include metals, plastics, composites, and the like.  
       INDUSTRIAL APPLICABILITY  
       [0037]     The disclosed floor-mounted control pedestal may provide improved tactile feedback to operators of any kind of work machine. The combination of the disclosed floor-mounted control pedestal with a suspended operator seat may provide a comfortable ride for an operator by insulating them from sudden and/or severe movements of the work machine chassis without sacrificing tactile feedback through the control pedestal.  
         [0038]     In particular, operators of motor graders may control the blade of the motor grader with a high level of precision. For example, finish grading requires positioning of the blade accurate to within roughly an inch or less. In order to achieve such accuracy, motor grader operators may rely heavily on tactile feedback to monitor the engagement of the blade with the earth. Operators may sense feedback about the load on the blade, which may be an indication of, among other things, how deeply the blade is cutting into the ground. With experience, operators may learn to interpret feedback and to assess whether the blade is positioned properly. Using this feedback, operators may make fine adjustments to the positioning of the blade. When the adjustment is made, a difference in tactile feedback may enable the operators to sense that the adjustment was made and thereby confirm that the ground is being sculpted in a desired manner.  
         [0039]     Although motor grader operators may benefit from tactile feedback through the controls, it is not necessarily desirable to transmit such feedback through the operator seat. Because much of the work done by motor graders may involve operation on unpaved surfaces and because the blade may be scraped across gravelly earth, the chassis of a motor grader may be subject to harsh vibrations and an overall rough ride. To provide riding comfort and enable operators to maintain their seating position, motor graders have been provided with suspended seats, which dampen the vibrations. The combination of a suspended seat and the disclosed control pedestal may provide operators of motor graders, as well as other work machines, riding comfort and stability, without sacrificing tactile feedback through the control pedestal. In addition, the adjustability of the disclosed control pedestal may provide versatility to an operator station to enable operators of different stature to comfortably, effectively, and efficiently use the same work machine. Sliding the disclosed armrest portion  56  aft may enable armrest portion  56  to be effectively retracted to facilitate ingress and egress from operator station  14 . Further, the sliding fore and aft adjustability of armrest portion  56 , as well as the height adjustability of base  46 , the height adjustability of arm support  60 , and the incline adjustability of arm support  60  may enable differently sized operators to not only adjust control pedestal  24  to comfortably support their arm, but also to position joystick  32  at a comfortable distance within their reach. It will be apparent to those skilled in the art that various modifications and variations can be made to the disclosed work machine control pedestal without departing from the scope of the invention. Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope of the invention being indicated by the following claims and their equivalents.