Abstract:
Changing operating characteristics of an implement can expand the capabilities of and enhances the productivity of the implement. The disclosed method and apparatus for changing operating characteristics of an implement comprises, providing the operating characteristics of the implement with a predetermined operational range consisting of a plurality of values, connecting the implement with a work machine, sending a first input signal identifying the operational range to an electronic control module, operating the implement at a first value within the operational range, sending a second input signal relating to a second value within the operational range to the electronic control module, and sending an output signal from the electronic control module to one of the work machine and the implement to change from the first value to the second value.

Description:
TECHNICAL FIELD  
       [0001]     This invention relates generally to changing operating characteristics of an implement, and, more particularly, to a method and apparatus for identifying the operational range of the operating characteristics of the implement and changing the operating characteristics within the operational range.  
       BACKGROUND  
       [0002]     Work machines such as integrated tool carriers, skid steer loaders, backhoe loaders, excavators, and a wide variety of other work machines typically have a plurality of hydraulically controlled implements that may be interchangeably attached to the work machine to perform a particular work function. These implements are normally controlled through an implement control system having one or more hydraulic systems that are used to actuate and control the implement&#39;s lift mechanism, tilt mechanism, or auxiliary mechanisms. These implements are likewise controlled through the use of various operator input devices such as one or more implement control levers, foot pedals, or joysticks. Many of these implements have a need for changeable operating characteristics. For example, a stump grinder needs to be able to increase its hydraulic flow rate so as to increase the cutting head speed when grinding a very hard stump. It is, therefore, beneficial to have the ability to change the operating characteristics of an implement.  
         [0003]     One known method of changing the operating condition of an implement of a power machine is described in U.S. Pat. No. 5,957,213 issued to Loraas et. al. on Sep. 28, 1999. It discloses a power machine and an implement suitable for attachment to the power machine, the implement including an electronic controller attached thereon and a power actuator removably attached thereto. The implement with the electronic controller attached thereto is configured to control the power actuator based on operator input signals from operator inputs. Having an implement with an electronic controller restricts the flexibility of the operation of the work machine by restricting the use of implements with the power machine to only those that have the electronic controller. Dependency on the electronic controller being attached to the implement requires that either the implement be manufactured or retrofitted with the electronic controller. Both of these requirements will increase the overall cost of the implement as compared to an implement that does not require the electronic controller to be attached thereto.  
         [0004]     The present invention is directed to overcoming one or more of the problems as set forth above.  
       SUMMARY OF THE INVENTION  
       [0005]     The present invention is a method for changing operating characteristics of an implement, comprising providing the operating characteristics of the implement with a predetermined operational range consisting of a plurality of values, connecting the implement with a work machine, sending a first input signal identifying the operational range to an electronic control module, operating the implement at a first value within the operational range, sending a second input signal relating to a second value within the operational range to the electronic control module, and sending an output signal from the electronic control module to one of the work machine and the implement to change from the first value to the second value.  
         [0006]     In another aspect of the present invention, a work machine is provided comprising a connectable implement having operating characteristics with a predetermined operational range consisting of a plurality of values, an electronic control module attached to the work machine, a first-end portion of a conducting device attached to the work machine, a second-end portion of the conducting device attached to the implement, wherein the attachment of the conducting device with the electronic control module and implement sets operation of the implement at a first value within the operational range, and signal means for changing from the first value within the operational range to a second value within the operational range. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0007]     For a better understanding of the present invention, reference may be made to the accompanying drawings in which:  
         [0008]      FIG. 1  is a side view of a work machine, such as a tracked skid steer loader, incorporating the apparatus for changing operating characteristics of a work machine;  
         [0009]      FIG. 2  is a top view the work machine, including a top view of an operator&#39;s compartment thereof; and  
         [0010]      FIG. 3  is a partial diagrammatic and a partial schematic representation of a hydraulic system of the work machine incorporating the present invention. 
     
    
     DETAILED DESCRIPTION  
       [0011]     Referring to the drawings, a method and apparatus for changing operating characteristics of an implement for use with a work machine  100  is shown. With particular reference to  FIG. 1 , the work machine  100  is depicted as a tracked skid steer loader. It should be understood, however, that the work machine  100  could be any sort of work machine that has hydraulically controlled implements that are removably attached thereto and not just those enumerated above. The work machine  100  has a body portion  103  having a front-end portion  106  and a rear-end portion  107 . The work machine includes a plurality of ground engaging support members  109  that support the body portion  103  and an operator&#39;s compartment  112  supported on the body portion  103 . Further, the work machine  100  includes a lift member assembly  121  pivotally attached to the body portion  106  and an implement  124  pivotally connectable with the lift member assembly  121 . The implement  124  has operating characteristics having a predetermined operational range consisting of a plurality of values, including a predetermined operational range of hydraulic characteristics. The work machine  100  also includes an electronic control module  127  and a hydraulic system  130  both of which are attached to the work machine  100  and are connected to one another as shown by truncated wires in  FIGS. 1 and 3 . Finally, the work machine  100  includes a conducting device such as a ground wire  133  having a first-end portion  136  connectable with the implement  124  and a second-end portion  139  connected to the electronic control module  127 . It should be understood, however, that the conducting device might also be a cable, wire, rod, or other such mechanism.  
         [0012]     As depicted in  FIG. 2 , the implement  124  includes at least one hydraulic hose  142  having a first-end portion  145  connectable with the implement  124  and a second-end portion (not shown) connected to the hydraulic system  130 . Although a broom is depicted in  FIGS. 1 and 2 , it should be understood that the implement  124  could be any hydraulically controlled implement with operational characteristics having a predetermined operational range, including an auger, broom, stump grinder, cold planer, or any other such implement. Further, it should be understood that the hydraulic operational characteristics could include hydraulic pressures, hydraulic flow rates, or any other hydraulic characteristic.  
         [0013]     Further, in  FIG. 1 , the lift member assembly  121  includes a pair of laterally spaced side members  147  located at the rear-end portion  107  of the body portion  103  and a pair of lift arms  150  pivotally attached to the laterally spaced side members  147 . The implement  124  is pivotally connectable with the lift arms  150  at the front-end portion  106  of the body portion  103 .  
         [0014]     Referring further to  FIG. 2 , the operator&#39;s compartment  112  has a bottom portion  200  and a first side portion  202  and a second side portion  203 . The operator&#39;s compartment  112  includes a seat  204  attached to the bottom portion  200 . The seat  204  includes an armrest  205  that is moveable between up and down positions so that when an operator (not shown) of the work machine  100  is seated in the seat  204  the armrest  205  can be moved into the down position to restrain the operator in the seat  204 . The operator&#39;s compartment  112  also includes an instrument panel  210  located on the first side portion  202  adjacent the seat  204 . The instrument panel  210  includes an operator input device such as a switch  215 , lever, or other similar mechanism located thereon such that the operator can request a change in the operating characteristics of the implement  124  by actuating the switch  215 . The operator&#39;s compartment  112  further includes at least one sensor  220  located therein and operably coupled to the electronic control module  127  such that the sensor  220  can sense when an operator is seated in the seat  204  or when the armrest  205  is in the down position or both. Such a system is described in greater detail in U.S. Pat. No. 6,186,260 B1, entitled: “ARM REST/SEAT SWITCH CIRCUIT FOR USE AS AN OPERATIONAL STATE SENSOR FOR A WORK MACHINE,” issued to Schenck et al. and assigned to the assignee of this application. It should be understood that, alternatively, a first sensor may be used to sense when the operator is seated in the seat  204  and a second sensor may be used to sense when the armrest  205  is in the down position. Finally, the operator&#39;s compartment  112  includes an additional pair of operator input devices such as a pair of joysticks  225  located adjacent to the seat  204  and attached to the first side portion  202  and the second side portion  203  of the operator&#39;s compartment  112 .  
         [0015]     As depicted in  FIG. 3 , the hydraulic system  130  includes a portion of a propel hydraulic circuit  301 , an implement hydraulic circuit  303 , a boost hydraulic circuit  306 , and a reservoir, such as a tank  308 . The propel circuit  301  includes a first source of pressurized fluid, such as a variable displacement pump  311  in fluid communication with the tank  308 .  
         [0016]     The implement circuit  303  fluidly controls the lift and tilt functions of the implement  124  as well as the auxiliary functions. Auxiliary functions may include the vertical or horizontal rotation of the implement  124  in any direction, the clamping of an implement, or any other function. The implement circuit  303  includes a second source of pressurized fluid, such as a first fixed displacement pump  315 . The first fixed displacement pump  315  is connected with the variable displacement pump  311  and both are in fluid communication with the tank  308 .  
         [0017]     The boost circuit  306  includes a third source of pressurized fluid, such as a second fixed displacement pump  318 . The second fixed displacement pump  318  is also connected with the variable displacement pump  311  and both are in fluid communication with the tank  308 . The boost circuit  306  further includes a two-position boost flow diverter valve  327  connected with the second fixed displacement pump  318  with a relief valve  321  interposed thereto. When the boost flow diverter valve  327  is in a first position  327   a,  the pressurized fluid returns to tank  308 . When the boost flow diverter valve  327  is in a second position  327   b,  the pressurized fluid flows to a two-position boost flow control valve  330 . When the boost flow control valve  330  is in a first position  330   a  it is in a “proportional flow” position and the pressurized fluid flows to an auxiliary control valve  336 . When the boost flow control valve  330  is in a second position  330   b  it is in a “full flow” position and the pressurized fluid flows to the implement circuit  303  to change the value of the hydraulic flow rate and hydraulic pressure of the auxiliary function of the implement  124  from a first value to a selected second value, e.g., to increase the hydraulic flow rate and hydraulic pressure to the selected second value. The auxiliary control valve  336  mentioned above is an infinitely variable valve having a first position  336   a,  a second position  336   b,  and a third position  336   c.  When the auxiliary control valve  336  moves toward the first position  336   a  a proportional amount of pressurized fluid flows through conduits  345  in a first direction so as to change the value of the hydraulic flow rate and hydraulic pressure of the auxiliary function of the implement  124  from a first value to a second value. The proportional amount of pressurized fluid is directly related to the distance toward the first position  336   a  the auxiliary control valve  336  moves. When the auxiliary control valve  336  is moved to the second position  336   b  pressurized fluid flow is blocked. Finally, when the auxiliary control valve  336  moves toward the third position  336   c  a proportional amount of pressurized fluid flows in an opposite direction of the first direction of the first position  336   a  so as to change the value of the hydraulic flow rate and hydraulic pressure of the auxiliary function of the implement  124  from a first value to a second value. The proportional amount of pressurized fluid is directly related to the distance toward the third position  336   c  the auxiliary control valve  336  moves. A pair of check valves  350 , each located in the conduit  345 , blocks all flow of the pressurized fluid when the auxiliary control valve  336  is in the second position  336   b.    
         [0000]     Industrial Applicability  
         [0018]     The method of changing operating characteristics of the implement  124  includes connecting the implement  124  to the work machine  100  by connecting the implement  124  to the lift arms  150 , connecting the first-end portion  136  of the ground wire  133  with the implement  124 , and thus connecting the implement  124  to the electronic control module  127 . The operator then climbs into the operator&#39;s compartment  112 , sits in the seat  204 , and lowers the armrest  205  to the down position. The operator then starts-up the work machine  100  so that it is in an operable condition.  
         [0019]     Once the operator has started the work machine  100 , the electronic control module  127  sends a signal to the implement  124  through the ground wire  133  requesting information as to the implement&#39;s  124  operating characteristics&#39; operational range characteristics, in particular the implement&#39;s  124  hydraulic characteristics&#39; operational range such as its hydraulic flow rate range and hydraulic pressure range. The implement  124  sends a first input signal back to the electronic control module  127  through the ground wire  133  advising it of the implement&#39;s  124  operating characteristics&#39; operational range. Once this is accomplished, based upon the first input signal, the implement  124  begins operation at a first value within the operational range such as operating at a first value of hydraulic flow rate and hydraulic pressure.  
         [0020]     When the operator desires to change the implement&#39;s  124  operating characteristics the operator will actuate the switch  215  on the instrument panel  210  requesting the change. Before the operating characteristics can be changed, however, at least one predetermined condition must be met. In this embodiment, the predetermined conditions are the work machine  100  must be in operable condition and the operator must actuate switch  215 . In order for the work machine  100  to be in an operable condition, the operator must be seated in the seat  204  and the armrest  205  must be in the down position. When the sensor  220  senses that the operator is in the seat  204  and the armrest  205  is in the down position and the operator has actuated the switch  215 , the predetermined conditions have been met and a second input signal is sent from the work machine  100  to the electronic control module  127  requesting a change in the implement&#39;s  124  operating characteristics. For example, if the operator desires to control the hydraulic characteristics of the hydraulic system  130  such as increasing the hydraulic flow rate and hydraulic pressure, the operator can request such by actuating the switch  215  and having the work machine  100  in the operable condition. In other words, if the operator is using an implement such as the broom  124  depicted in  FIG. 1 , and the operator encounters heavier debris and the current rotational speed of the broom  124  is not sufficient, the operator can increase the hydraulic flow rate and hydraulic pressure to accelerate the rotational speed of the broom  124  by actuating the switch  215  and having the work machine  100  in the operable condition, thus brushing away the heavier debris.  
         [0021]     Once the electronic control module  127  receives the second input signal signifying that the work machine  100  is in operable condition and that the operator desires a change in the operating characteristics, the electronic control module  127  sends an output signal to either the work machine  100  or the implement  124  to change the operating characteristics of the implement  124 . For example, the electronic control module  127  receives the second input signal then sends the output signal to the implement  124  to change the hydraulic characteristics of the hydraulic system  130  by increasing the hydraulic flow rate and hydraulic pressure. This is accomplished by responsively interfacing the hydraulic system  130  with the second input signal. More specifically, this is accomplished by responsively interfacing the boost flow diverter valve  327 , boost flow control valve  330 , and the auxiliary control valve  336  with the second input signal. The electronic control module  124  sends a signal to the boost circuit  306  to activate the boost flow diverter valve  327 . Pressurized fluid from the second fixed displacement pump  318  is then sent to the boost flow control valve  330 .  
         [0022]     When the boost flow diverter valve  327  is in the first position  327   a  the boost flow circuit  306  is not activated and the implement  124  does not receive increased hydraulic flow or hydraulic pressure. To vary the operating characteristics, the boost flow diverter valve  327  must be in the second position  327   b.  When the boost flow control valve  327  is actuated so that it is in the second position  327   b  and the boost flow control valve  330  is actuated so that it is in the second position  330   b,  the boost flow circuit  306  is at “full flow” and the pressurized fluid from the second fixed displacement pump  318  flows to the implement circuit  303  so as to change from the first value to the second value, e.g., increase the implement&#39;s hydraulic flow rate and hydraulic pressure. When the boost flow diverter valve  327  is in the second position  327   b  and the boost flow control valve  330  is in the first position  330   a,  the boost flow circuit is at “proportional flow” and the pressurized fluid from the second fixed displacement pump  318  flows to the infinitely variable auxiliary control valve  336 . When the infinitely variable auxiliary control valve  336  is in the second position  336   b,  the boost flow circuit  306  is not activated and the implement  124  does not receive increased hydraulic flow or hydraulic pressure. When the infinitely variable auxiliary control valve  336  is actuated so that it moves toward the first position  336   a  or the third position  336   c,  a proportional amount of the pressurized fluid flows to the implement circuit  303  so as to proportionally increase the implement&#39;s  124  hydraulic flow rate and hydraulic pressure. The amount of increase is related directly to the amount of movement of the infinitely variable auxiliary valve  336  toward the first position  336   a  or the third position  336   c.    
         [0023]     As described herein, the present method of changing operating characteristics of an implement has particular utility in any work machine  100  that operates with a plurality of different implements  124  or where a particular implement  124  functions under different operating characteristics.  
         [0024]     Other aspects, objects and advantages of the invention can be obtained from a study of the drawings, the disclosure and the appended claims.