Abstract:
A tree harvesting guide bar adapted for treating stumps with a treatment material as the tree is being harvested is provided, and more particularly a valve arrangement for enabling connection of the guide bar inlet to treatment material sources on a variety of different harvesting machines is disclosed, such that the inlet not connected to the treatment material source does not need to be independently and manually plugged to prevent undesirable oufflow.

Description:
FIELD OF THE INVENTION  
       [0001]     This invention relates to a guide bar for tree harvesting machines, the bar having a perforated conduit embedded in the opposing sides of the bar, the conduits connectable to a stump treatment material source and, more particularly, it relates to a valve arrangement for adapting the bar to different tree harvester machines by enabling connection to conduit from either side of the bar.  
       BACKGROUND  
       [0002]     A basic guide bar adapted for treating stumps is disclosed in commonly owned U.S. Pat. No. 6,397,452. That patent illustrates the provision of conduits that are seated in channels formed in the opposing sides of the bar. It further illustrates the connection of the fluid source to the conduit on the underside of the bar (understanding that either side may be the underside and the bar is typically inverted over time so as to extend the wear life of the bar).  
         [0003]     What is not evident from the above patent or prior art is that different tree harvesting machines have different routes for connecting the treatment material source to the guide bar. One route directs the flow of liquid to the top of the bar and the other directs the flow of liquid to the bottom of the bar, both feeding the conduit on the underside of the bar.  
         [0004]     As shown in the partial cross-sectional view of a guide bar of  FIG. 2 , currently, to accommodate both feeding routes, receiving inlets  234 ,  236  are provided at both sides of bar  222  and penetrate conduit  240 . As shown, side  244  is the under side where treatment material will be dispersed through perforations  246  in conduit  240 . Plug  230  prevents the treatment material from escaping through near end  232  of conduit  240 . Currently, when a bar is purchased, the purchaser must determine which of the inlet  234 ,  236  is the correct inlet for his or her machine and the opposing side inlet to that conduit needs to then be sealed, otherwise it becomes an outlet for the treatment liquid. Such sealing has been heretofore achieved by providing the bar purchaser with a plug sized to fit inlets  234 ,  236 , which is usually manually inserted in the unused inlet.  
         [0005]     Inserting the plug into the inlet is an undesirable, time-consuming and oftentimes awkward task. And, if the plug is improperly inserted or if the plug is dropped, lost or not inserted at all, the user will experience an undesired outflow of treatment material onto the machine and ground. This can render the flow of the treatment material onto the stump surface insufficient, and can also increase costs.  
         [0006]     The present invention is directed to the resolution of the above-described problem whereby the insertion of inlet plugs is avoided.  
       BRIEF DESCRIPTIONS OF THE INVENTION  
       [0007]     Whereas the inlets for the conduit are directly opposite each other, whereas they are typically located near the inner end of the conduit and whereas the ends of the conduits are usually sealed by plugs at the point of manufacture, one preferred embodiment includes modification of the end plugs at the inner ends of the conduits so as to incorporate a check valve as a part of the end plug. The check valves may be open or closed biased, and are reactive to the pressure applied by the treatment material as it is introduced to an inlet.  
         [0008]     In some embodiments, the end plug may carry the check valve. In a closed biased setup, a portion of the valve opens in response to the treatment material flow, thereby allowing the treatment material into the conduit, while a portion of the valve remains closed at the opposed inlet to prevent unwanted outflow. In an open biased valve configuration, the force of the treatment material causes the valve to close off the inlet where the treatment material is not being introduced and thus preventing unwanted outflow.  
         [0009]     In other embodiments of the present invention, the check valve is not carried by the end plug, but may still have either an open or closed biased setup that is reactive to the introduction of treatment material. For example, a flexible or collapsible layer may be applied adjacent to a portion of the conduit inner wall and covering the opposed inlets. Fluid directed through one of the inlets forces the portion of the layer covering the inlet to collapse, thus allowing the treatment material to flow into the conduit while the portion of the layer overlaying the opposed inlet remains closed preventing outflow. Further versions are contemplated and several are illustrated and described in the detailed description that follows and which have reference to the accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]     The invention is illustrated by way of example and not by way of limitation in the figures of the accompanying drawings, in which the like references indicate similar elements and in which:  
         [0011]      FIG. 1  illustrates a stump treatment guide bar coupled to a tree harvester;  
         [0012]      FIG. 2  illustrates a cross section of a portion of a known stump treatment guide bar;  
         [0013]      FIGS. 3A and 3B  illustrate cross-sectional views of a portion of a guide bar in accordance with a first embodiment of the present invention;  
         [0014]      FIGS. 4A and 4B  illustrate cross-sectional views of a portion of a guide bar in accordance with a second embodiment of the present invention;  
         [0015]      FIG. 5  illustrates a cross-sectional view of a portion of a guide bar in accordance with a third embodiment of the present invention; and  
         [0016]      FIG. 6  illustrates a cross-sectional view of a portion of a guide bar in accordance with a fourth embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION  
       [0017]     In the following detailed description, reference is made to the accompanying drawings which form a part hereof wherein like numerals designate like parts throughout, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the present invention. Therefore, the following detailed description is not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims and their equivalents.  
         [0018]      FIG. 1  illustrates an example of a stump treatment guide bar interconnected to a tree harvester. Boom  10  of a tree harvester has a head portion  12  that includes grapples  14  and a cutting assembly  16  pivotally mounted thereon. Cutting assembly  16  includes a cutting chain  21  mounted for driven rotation around a guide bar  22 . As the grapples  14  encircle and then grip the trunk of a tree  24 , cutting assembly  16  is then pivoted into and through the tree  24  as indicated by arrows  25 . As the cutting assembly  16  cuts through the tree  24 , the flat underside of bar  22  slides along or in close proximity to the exposed surface  28  of the stump. It is this exposed surface  28  that needs treating.  
         [0019]     For treatment of surface  28 , a channel  32  may be formed in each of the bar sides ( FIG. 1  being a view from the upper side of the bar and the underside channel is shown in dashed lines). A conduit  30  is secured in the channel  32  and is connected to a treatment material source  20  at either opposed inlets  34 ,  36 , depending on which side the tree harvester is configured to dispense such treatment material. As illustrated, source  20  is connected to inlet  36  on the top side of bar  22  by line  26 . Again, other harvesters may be configured to interconnect the treatment material source  20  with inlet  34  on the underside of guide bar  22 .  
         [0020]     Outlet holes or perforations  38  may be formed in conduit  30  and open to the underside of the bar  22 . The perforations  38  adapted to direct the treatment material from conduit  30  onto surface  28 . It can be appreciated by one skilled in the art, however, that perforations  38  can be formed in conduit  30  at the point of manufacture, or they can be formed by the user to customize the necessary application of treatment material depending, for example, on the material being dispersed and/or the trees being cut.  
         [0021]      FIGS. 3A and 3B  illustrate cross sectional-views of a portion of a guide bar in accordance with a first embodiment of the present invention. Guide bar  322  is similar to those described with respect to  FIG. 1 , having channel  332  formed therein. Conduit  340  has a near end  318  and an outside end (not shown), and is disposed in channel  332  such that perforations  346  are positioned at or near the underside  344  so treatment material can flow out therefrom and treat the stump exposed surface (not shown, but shown in  FIG. 1 ).  
         [0022]     Plug  330  is positioned in the near end  318  of conduit  340  to prevent treatment material from exiting therefrom. Plug  330  carries a check valve  350 . As illustrated, check valve  350  is a generally tubular-shaped hollow extension of plug  330  that is substantially pliable or collapsible such that it may conform to the inner surface of conduit  340 . The tubular extension  350  extends to a point past the receiving inlets  334 ,  336 . It is preferable that the outer diameter of the tubular extension check valve  350  be substantially the same as the inner diameter of the conduit  340 , so that the extensions  350  cover inlets  334 ,  336 , thus creating a closed biased arrangement. It can be appreciated, however, that the outer dimension of the tubular extension could be slightly larger, particularly where the selected material is pliable such that it may deform to fit within conduit  340 .  
         [0023]      FIG. 3B  illustrates the response of the check valve  350  when treatment material is introduced from the source (not shown) through inlet  334 . As the treatment material is directed through inlet  334 , it causes the portion of check valve  350  that is covering inlet  334  to deflect or collapse inwardly as indicated by directional arrow  352 . This deflection in response to the treatment material flow thereby opens inlet  334  and allows the material to flow into conduit  340  and out perforations  346 , thereby performing the stump treatment process.  
         [0024]     The treatment material is prevented from flowing out of inlet  336  in part because the portion of check valve  350  covering inlet  336  does not deflect inwardly, and thus remains in the closed position. Depending on the pressure at which the treatment material is introduced, the deflecting portion of check valve  350  may also push against the portion of check valve  350  that remains in the closed position over inlet  336 , thereby enhancing the seal of inlet  336  and increasing the resistance to undesired outflow.  
         [0025]     The arrangement shown in  FIG. 3B  is one where the tree harvester (not shown) is configured to insert treatment material from the under side  344  of the guide bar  322  through inlet  334 . However, check valve  350  will function as described where a tree harvester is used that dispenses treatment material from the top side  342  through inlet  336 . In such a case, the portion of check valve  350  that is covering inlet  336  will deflect inwardly thereby allowing treatment material to flow into conduit  340 . The presence of the portion of check valve  350  covering inlet  334  will remain in place and prevent outflow of treatment material therefrom.  
         [0026]     It can be appreciated by one skilled in the art that the cross-sectional dimension of check valve  350  may also be smaller than the cross-sectional dimension of conduit  340 , which would create an open biased arrangement. When the treatment material is introduced, it will cause the deflection of the tubular extension such that it covers the opposing inlet.  
         [0027]      FIGS. 4A and 4B  illustrate cross-sectional views of a portion of a guide bar in accordance with a second embodiment of the present invention. As with FIGS.  3 A and  3 B, Guide bar  422  has channel  432  formed therein. Conduit  440  has a near end  418  and an outside end (not shown), and is disposed in channel  432  such that perforations  446  are positioned at or near the underside  444  to allow treatment material to flow therefrom and treat the stump exposed surface (not shown).  
         [0028]     A plug  430  is positioned in the near end  418  of conduit  440  to prevent treatment material from exiting therefrom. Plug  430  carries a check valve  450 . Check valve  450  consists of a generally planar flap that extends outward from the inner end  431  of plug  430  in a substantially parallel manner to conduit  440 , to a point past the opposing inlets  434 ,  436 . In its neutral position, the flap of check valve  450  generally maintains a substantially similar distance from inlets  434 ,  436 , thus leaving inlets  434 ,  436  in an open biased position.  
         [0029]     As shown in  FIG. 4B , when treatment material is directed into inlet  434 , check valve  450  deflects toward opposed inlet  436 , as shown by arrow  452 . When deflected, check valve  450  is forced against inlet  436  thereby sealing it such that undesirable outflow of the treatment material there through is prevented without the need for inserting a plug into inlet  436 .  
         [0030]     Though check valve  450  is shown to be substantially flat, it can be appreciated by one skilled in the art that the cross-sectional shape of flap portion of the check valve  450  can be varied, while still achieving similar results. For example, the flap cross sectional shape could be more oblong in order to better match the inner curvature of the conduit  440  at the inlets  434 ,  436  and thus encourage a better seal.  
         [0031]     Also, as discussed with  FIG. 3B , the illustrated configuration anticipates a tree harvester that is configured to direct treatment material from the under side  444  to inlet  434 . However, it can be appreciated that the same result may be achieved if treatment material is directed to inlet  436  on the top side  442 . In such a case, though not shown, check valve  450  will deflect in response to introduction of treatment material through inlet  436  thereby forcing the flap of check valve  450  against opposed inlet  434 , and thus sealing it to prevent unnecessary outflow.  
         [0032]      FIGS. 5 and 6  are cross sectional-views of a portion of a guide bar in accordance with additional embodiments of the present invention where the check valve is not carried by the plug.  FIG. 5  illustrates a check valve  550  which operates similar to the tubular extension check valve embodiment shown in  FIGS. 3A and 3B , except plug  530  does not carry the check valve  550 . Instead, check valve  550  is a flexible layer of deflectable material residing adjacent to the inner wall of conduit  540  at the near end  518 . Flexible layer check valve  550  extends past the inlets  534 ,  536  thereby maintaining a closed bias. When treatment material in directed into inlet  536 , for example, the portion of the flexible layer of check valve  550  that covered inlet  536  deflects toward opposed inlet  534 , as shown by dashed lines  550 ′ and arrow  552 . This allows the treatment material to flow into conduit  540  without flowing out of inlet  534 .  
         [0033]     Flexible layer check valve  550  can be held into place by plug  530  at the inner end  518 . Though not shown, inner end  518  can also be crimped or otherwise sealed to prevent out flow, as well as hold tubular layer check valve  550  in place.  
         [0034]      FIG. 6  illustrates another embodiment of a guide bar in accordance with the present invention where the check valve is not carried by the plug. As shown, check valve  650  is similar to and correspondingly functions like the planar flap check valve described in  FIGS. 4A and 4B . But, instead of being carried by a plug, the check valve  650  is held in a position between the opposing inlets  634 ,  636  by the deformation or crimping  633  of near end  618  of conduit  640 . Check valve  650  extends from the crimping  633  to a point past inlets  634 ,  636 . When treatment material is directed into conduit  640  through inlet  634  on under side  644 , for example, check valve  650  deflects toward opposing inlet  636  as shown by 650′, thereby sealing inlet  636  and preventing undesirable outflow. Likewise, if treatment material is directed through inlet  636 , check valve  650  will deflect toward opposing inlet  634  as shown by  650 ″, thereby sealing inlet  634  and preventing undesirable outflow.  
         [0035]     Check valves described above can be made out of a variety of materials depending on a variety of factors. It is preferable that the check valves be made of a pliable material that will be responsive to the pressures induced by the flow of treatment material. Examples of such a material are many polymer-based rubber materials, including, but not limited to, polyurethane, polypropylene and the like. Finally, it can be appreciated by one skilled in the art that the end of the conduit can be sealed or crimped in a variety of ways in addition to that shown in the figures, without departing from the scope of the invention.  
         [0036]     It can also be appreciated that there may be a slight advantage of the closed biased check valve embodiments (i.e., the tubular extension check valve embodiment illustrated in  FIGS. 3A and 3B  and flexible layer check valve embodiment illustrated in  FIG. 5 ) over the example open biased flap check valve embodiments of  FIGS. 4A and 4B , and  FIG. 6 . The former check valves eliminate the potential need to orient the plug as may be required of the latter flap check valves, i.e., so that the plane of the flap is positioned perpendicular relative to a center line passing through the opposing inlets. Also, the closed biased configuration of the tubular extension check valve and flexible layer check valve embodiments will prevent treatment material from flowing out of the inlets when the treatment material is not being directed to the guide bar from the source (e.g., when moving from one tree to the next).  
         [0037]     Although specific embodiments have been illustrated and described herein for purposes of description of the preferred embodiment, it will be appreciated by those of ordinary skill in the art that a wide variety of alternate and/or equivalent implementations calculated to achieve the same purposes may be substituted for the specific embodiment shown and described without departing from the scope of the present invention. Those with skill in the art will readily appreciate that the present invention may be implemented in a very wide variety of embodiments. This application is intended to cover any adaptations or variations of the embodiments discussed herein. Therefore, it is manifestly intended that this invention be limited only by the claims and the equivalents thereof.