Patent Publication Number: US-9409310-B2

Title: Combined feed roller and conveyor sprocket/pulley for a tree chipper

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     U.S. patent application Ser. No. 13/206,245, filed Aug. 9, 2011, entitled “INDIVIDUAL FEED CHAIN TENSION SYSTEM FOR TREE CHIPPER”, now abandoned, which is incorporated herein by reference in its entirety. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to feed control for a log and/or tree chipper. More particularly, the invention relates to an apparatus for improving the feeding performance of the infeed system of a log and/or tree chipper without increasing the cost or complexity thereof by providing an additional feed roller under the main feed roller on the feed table of a log/tree chipper. 
     2. Background Art 
     The present state of the art in large log/tree chippers is to help assist feeding with an infeed conveyor on the feed table. The infeed conveyor is typically a series of WD style drag chains running side by side. The individual drag chains may have a small, occasional tooth welded to the side of the chain every four to eight links to assist in the movement of material. The chain runs around a head pulley and a tail pulley assembly. The head pulley is made up of a shaft with a wide sprocket welded to the shaft at every drag chain. The sprocket drives the infeed chain and the infeed chain moves the material to be fed. The lack of aggressive features means that the chain will move material laying on it as long as it does not meet restriction from other infeed features. If the material is restricted, then the chain and head pulley slip underneath the material and the upper feed roller is thereby forced to do all of the work. To solve this problem one manufacturer of this type of machine has begun to install a lower feed roller between the head pulley and the cutter drum shear bar. This lower feed roller has aggressive knives welded to the outside surface to bite into the wood like the top, main, feed roller. With this aforementioned arrangement, the wood is pinched between an upper and lower aggressive feed roller and is more likely to overcome restrictions as the wood is forced towards the cutter drum. A disadvantage is that this adds expense, complexity, and increased possibilities for failure. The additional expense is in the production of the added feed roller and the drive system for it. The additional complexity results from there being more parts required, especially in combining the drives effectively of the main feed roller and the added lower one. The increased failure points result from the use of the needed additional bearings, the drive system, also resulting in more locations for material to wrap around one of the additional shafts. 
     There is, therefore, a need for a method and apparatus for overcoming the aforementioned problems with prior art feed roller systems for large tree/log chippers. 
     BRIEF SUMMARY OF THE INVENTION 
     In the present invention, fewer moving parts are used to solve the aforementioned feed roller problem by adding log engaging lugs on the pulley/sprocket closest to the feed roller instead of having both a pulley/sprocket nearest the feed roller and an additional feed roller that rotate on a different axis near the top of the feed table adjacent to the main feed roller. 
     The log/tree chipper has an infeed with a roller member, such as a sprocket or pulley, guides a chain has at least one lug in the roller member, such lug extending above the outer surface of the chain and above a feed table. One or more auxiliary feed members with lugs can rotate with and along the same axis of rotation of the roller member and be spaced to one side of a roller member. The auxiliary feed member can be positioned at the material exit end of a feed table, or at both ends of a feed table. Lugs on the auxiliary feed members and/or the roller members/sprockets are, in some embodiments, positioned at the material exit end of the feed table work so as to work in a symbiotic relationship with the main feed roller. 
     In some embodiments of the present invention an additional feed roller is placed to one side of one of the feed chain(s) on the feed table, instead of under the main feed roller as in the prior art, and in other embodiments such additional feed roller(s) is(are) placed adjacent one or more feed chains or conveyors on the feed table, with or without the additional lugs on the pulley/sprocket closest to the main feed roller, the additional feed roller(s) rotating about the same axis, and preferably even on the same shaft, as the adjacent pulley/sprocket. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a whole tree chipper constructed in accordance to the present invention with a feed table having two drag chains for moving logs/trees to a feed roller, and showing log engaging structures on sprockets and an auxiliary feed roller extending above the feed table adjacent the main feed roller; 
         FIG. 2  is a perspective view of the chipper of  FIG. 1  with a portion of the feed table removed to show an feed chain trained around a powered drive sprocket near the feed roller and an idler sprocket at a material entrance end of the feed table; 
         FIG. 3  is an enlarged perspective view of the two chains and the drive system therefore of  FIG. 1  with the feed table removed to show an feed chain trained around a powered drive sprockets near the feed roller and a idler sprockets at a material entrance end of the feed table; 
         FIG. 4  is a side elevational view of the chipper from the side of  FIG. 2  with a portion of the feed table removed to show a chipper drum, the main feed roller, an feed chain trained around a powered drive sprocket near the feed roller and an idler sprocket at a material entrance end of the feed table; 
         FIG. 5  is an enlarged perspective view of the sprockets closest to the main feed roller as shown in  FIG. 3 , and also showing portions of the drive system that powers these sprockets; 
         FIG. 6  is a partial top view of the structure shown in  FIG. 5 ; 
         FIG. 7  is a cross sectional view taken along line  7 - 7  of  FIG. 6 ; 
         FIG. 8  is a cross sectional view taken along line  8 - 8  of  FIG. 6 ; 
         FIG. 9  is an enlarged top view like  FIG. 6 , but showing mainly only those portions of the sprockets, chains and auxiliary feed roller that are located closest to the main feed roller; 
         FIG. 10  is an enlarged, partial side view taken from the right side of  FIG. 6 , and showing the phase difference between the first and second log engaging structures on the sprockets shown and the lugs on the auxiliary feed roller; 
         FIG. 11  is an exploded perspective view of the main feed roller and the system for mounting it to the frame of the machine, the arrow showing how the main feed roller can pivot up and down as material goes under it by pivoting a feed roller sub-frame which is pivotally attached to the main frame of the machine; 
         FIG. 12  is a top, somewhat schematic view, of the feed table, cutter drum, showing the two feed chains and the mounting sprockets that the chains are trained around; 
         FIG. 13 , an alternate embodiment, shows a top, somewhat schematic view, of a feed table, cutter drum, showing only one feed chain and the mounting sprockets that the chain is trained around, and also including auxiliary feed rollers on each side of the sprockets closest to the main feed roller; and 
         FIG. 14 , also an alternate embodiment, is similar to  FIG. 13  except that a conveyor belt comprising a plurality of metal plates replaces the conveyor chain which conveyor belt is trained around pulleys which do not have log engaging structures on them like the sockets of the  FIG. 13  embodiment, relying on an auxiliary feed roller on each side of the pulley adjacent the main feed roller to help feed the material from the feed table past the main feed roller and the feed table towards the cutter drum, the auxiliary feed rollers being attached to the pulley and rotating around the same axis as that pulley closest to the main feed roller; 
         FIG. 15 , another alternate embodiment, is a cross sectional view similar to  FIG. 4 , but using another auxiliary feed structure, in addition to the essentially duplicate auxiliary feed member closer to the main feed roller, the additional auxiliary feed rotary member is attached to the idler sprocket for rotation with the idler sprocket and having lugs thereon extending radially outwardly between the chain links and above the feed table for contacting trees or logs as they enter the feed table and moving them towards the chipper drum; and 
         FIG. 16  is a top view of the  FIG. 15  embodiment. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     With reference now to the various figures in which identical elements are numbered identically throughout, a description of various exemplary aspects of the present invention will now be provided. The preferred embodiments are shown in the drawings and described with the understanding that the present disclosure is to be considered an exemplification of the invention and is not intended to limit the invention to the embodiments disclosed. 
       FIG. 1  shows log or whole tree chipper  10 , with a feed table  11  having two feed chains  12  for moving trees or logs towards a feed roller  13 . As in chippers in general, the feed roller  13  forces the logs or trees towards a chipping drum  14 , as best shown in  FIG. 4 . The material reducing or chipping drum  14  cuts the wood into small chips and forces the small chips out a chute  15  as is typical of chippers of any size. 
     The brush chipper  10  is mounted on wheels  16  ( FIG. 1 ), however, tracks and skids may also be used, and the brush chipper  10  may be stationary as well. The present invention is not limited to any particular conveyance apparatus, nor does it require the brush chipper  10  be portable. 
     Generally, the brush chipper  10  has a rear, feed end  11   a  and a front, outfeed end,  15   a . A feed direction is defined, for the purposes of this document, including the claims, as the direction the brush is forced while it is being chipped; that is, the feed direction is the direction going from the feed end, or material entrance end at  11   a , to the out feed, or material exit end, of the chipper  10 , towards outfeed end  15   a  when the chute  15  is in the position shown in  FIG. 1 . 
     The brush chipper machine  10  for processing logs and whole trees has a frame  20 . The material reducing drum  14 , shown best in  FIG. 3 , is operatively rotatably attached to the frame  20 . The feed table  11  is bolted to the frame  20  for receiving and supporting trees and logs thereon, the feed table  11  having a top, a bottom, a front end and a rear end. 
     Looking to  FIG. 4 , the feed roller  13  is disposed between the feed table  11  and the material reducing drum  14  and is rotatably attached to a sub-frame  13   sf  about rotational axis  13   a . The sub-frame  13   sf  is pivotally attached about pivotal axis  13   pa  so that the feed roller  13  can move up or down as logs/trees move there under towards the material reducing drum  14 . 
       FIG. 1  shows a pair of mostly vertical walls  21  on each side of the feed roller  13 , the walls  21  having a front and a rear and being farther apart at the rear thereof than at the front thereof for funneling logs and trees from the feed table  11  to the feed roller  13  and eventually to the material reducing drum  14 . 
     Looking to  FIGS. 1 and 2 , a first powered drive member, sprocket  24 , (which could also be a pulley) is operatively rotatably attached to the frame along a first substantially a horizontal axis  23  located below the top, front end of the feed table  11 . A second powered drive member, sprocket  25 , (which could also be a pulley) is operatively rotatably attached to the frame along a second substantially horizontal axis located below the top, front end of the feed table  11 , which second substantially horizontal axis can be coincident with the first substantially horizontal axis  23 . 
     Looking now to  FIGS. 1-6 , a first idler member, sprocket  26  (which could also be a pulley type idler) is operatively rotatably attached to the frame along a third substantially horizontal axis  28  ( FIG. 6 ) located below the top, rear end of the feed table  11 . A second idler member  27  (sprocket or pulley) operatively rotatably attached to the the frame along a fourth substantially horizontal axis  29  ( FIG. 6 ) located below the top, rear end of the feed table  11 . 
     Looking now to  FIGS. 1-4 , there is a first feed conveyor chain  12 , less than half the width of the feed roller  13 , the first feed conveyor chain  12  being trained around the first powered drive member  24  and the first idler member  26  for selectively moving the logs and trees along the feed table  11  to the feed roller  13 . A second feed conveyor chain  12  is also less than half the width of the feed roller  13 , the second feed conveyor chain  12  being trained around the second powered drive member  25  and the second idler member  27  for selectively moving the logs and trees along the feed table  11  to the distance between the first substantially horizontal axis  23  and the third substantially horizontal axis  28  can be the same or can be a variable distance as disclosed in U.S. patent application Ser. No. 13/206,245, filed Aug. 9, 2011, now abandoned, which is incorporated herein by reference in its entirety. 
     Looking at  FIG. 5 , a sprocket  24  has a rotating shaft  24   s  with discs  24   a  and  24   b  rigidly attached thereto so that when driven by hydraulic motor  41 , sprocket  42  will turn, causing chain  44  to transmit that rotation to sprocket  43 , which will rotate both sprockets  24  and  25 . Sprocket  25  is constructed like sprocket  24 , with a center shaft portion  25   s , spaced apart discs  25   a  and  25   b . Also rigidly turning with the sprockets  24  and  25  is an auxiliary feed member  40 , shown in  FIG. 5  as being made with two discs having lugs  40   c  and  40   d  alternatively around the exterior periphery thereof. Sprockets  24  and  25  and auxiliary feed member  40  are all rigidly attached to each other. The lugs  40   c  are in rotational phase with lugs  24   c  on the sprocket  24  so that the lugs  40   c  and lugs  24   c  work together as the assembly  24 ,  25  and  40  rotate, to push a tree or log towards the main feed roller  13  and ultimately on towards the cutter drum  14  shown in  FIG. 15 , for example. Similarly, lugs  25   d  on sprocket  25  are aligned in phase with the rotation of lugs  40   d  on auxiliary feed member  40 . Every other lug on auxiliary feed member  40  is a lug  40   c  aligned with a corresponding lug  24   c  on sprocket  24  and every other lug  40   d  on auxiliary feed member  40  is a lug  40   d  that aligns with lugs  25   d  on sprocket  25 . All of the lugs  40   c  and  40   d  are identical on the embodiment shown. Similarly, all of the lugs  24   c  and  25   d  are identical in the embodiment shown in  FIG. 5 , for example. By alternating the pushing of the log or tree between lugs  24   c  on one side and then alternatively lugs  25   d  on the other side sequentially, less hydraulic pressure is required than if all of the lugs  24   c  and  25   d  were pushing together at the same time instead of being out of phase with respect to each other as they rotate. 
     Looking at  FIGS. 5 and 6 , the lug structure  24   c ,  25   d ,  40   c  and  40   d  are all disposed for rotation about the first substantially horizontal axis  50 , the lug structure  24   c ,  25   d ,  40   c  and  40   d  being operatively attached to and rotating with the first sprocket  24 . This lug structure of lugs  24   c ,  25   d ,  40   c  and  40   d  is disposed above the feed table at times during rotation of the assembly of sprockets  24  and  25  and auxiliary feed member  40  so that the lugs contact material on the feed table and move the material towards the material exit end of the feed table, namely towards the main feed roller  13  and cutter drum  14 . Locating these lugs  24   c ,  25   d ,  40   c  and  40   d  near the main feed roller  13  causes the lugs to work in close conjunction with the main feed roller  13  so they are much more effective than prior art auxiliary feed rollers such as feed rollers  22  as shown in FIG. 1 of U.S. Pat. No. Re31,048, for example. Lugs  24   c ,  25   d ,  40   c  and  40   d  push logs up and forward toward the main feed roller  13  while at the same time the main feed roller  13  is pushing down and pulling the log forward, towards the cutter drum  14 , in close proximity to the forces applied by the lugs  24   c ,  25   d ,  40   c  and  40   d.    
     The chain  12  on the left as shown in  FIG. 1 , has bars  12   b  ( FIGS. 9 and 10 ) that extend across the sprocket  24  and ride in grooves  24   d  as shown in  FIG. 5 . Between each depression or groove  24   d  in the discs  24   a ,  24   b  the lugs  24   c  are welded at each end thereof to the discs  24   a  and  24   b . These lugs  24   c  therefore stick up through openings in the chains  12  as shown in  FIGS. 1, 2, 3, 9 and 10 . The same thing is happening with the chain  12  and lugs  25   d  welded to discs  25   a  and  25   b , since in the embodiment shown sprockets  24  and  25  are essentially identical except for being mounted to rotate together with the respective lugs  24   c  and  25   d  out of phase with each other. 
     In  FIG. 4 , the auxiliary feed member  140  is of a different configuration than the auxiliary feed member  40  shown in  FIGS. 1-3 and 5-9 , but the lugs  140   c  and  140   d  work just the same as lugs  40   c  and  40   d  on auxiliary feed member  40  and are in phase with lugs  24   c  and  25   d  respectively. 
     The relative widths of the discs  24   a  and  24   b  with respect to the much wider lugs  24   c  is significant, thereby allowing for much more area to catch and push a log than if lugs  24   c  were just radially outward extensions of the same width as discs  24   a  and  24   c . So the structure of lugs  24   c , extending up through openings in the open chain  12  provides significant advantages over the prior art. Since sprockets  24  and  25 , except for being out of phase, are identical, the same advantages accrue to lugs  25   d  on sprocket  25  as lugs  24   c  do on sprocket  24 . 
     Also, the relative narrow width of auxiliary feed rollers  40  and  140  as compared to the lugs  24   c  and  25   d  on sprockets  24  and  25  permits all of these lugs  24   c ,  25   d ,  40   c  and  40   d  to all fit in a relatively narrow space on the feed table adjacent the material exit end of the feed table adjacent the main feed roller  13 , with the lugs  24   c  and  25   d  in a preferred embodiment being at least twice as wide as lugs  40   c  and  40   d . While this is an optimum arrangement, there are significant advantages to having even one set of lugs  24   c ,  25   d ,  40   c  or  40   d  on the feed table  11  and not any of the other ones. Any combination of use of the lugs  24   c ,  25   d ,  40   c  or  40   d  sticking up through the feed table  11  would be helpful to keeping the material moving to the main feed roller  13  and to the cutter wheel  14 . 
       FIG. 12  shows an alternate embodiment  100  where sprockets  124  and  125  at the material entrance end of the feed table  11  are identical to the sprockets  24  and  25  at the material exit end except that the sprockets  124  and  125  are idler sprockets instead of driven sprockets. So the lugs on these sprockets  124  and  125  will also push logs on the feed table toward the cutter drum  14 . 
       FIG. 13  shows an alternate embodiment  200  with a front sprocket  224  that is like sprocket  24  of  FIGS. 1-10 , except that it is wider. Also, there are two auxiliary feed rollers  240  that are like auxiliary feed roller  40  of  FIG. 5 , but relatively narrower. So logs on the feed table  211  would be moved by the chain  212  towards the lugs  224   c  on roller  224  and those lugs  224   c , in conjunction with the lugs on auxiliary feed rollers  240  will push the log towards the main feed roller  13  and towards the cutter drum  14 . 
       FIG. 14  is an alternate embodiment  300  showing an infeed table  311  having metal plates  350  between the two chains  351  and  352 , to function like a solid conveyor, so that all that is seen in  FIG. 14  are the joints between the metal plates, with chains  351  and  352  on each side of the plates  350 . This type of conveyor would not be able to have lugs extending through these plates  350 , but having the auxiliary feed rollers  340  provides significant advantages as explained above. Pulleys  324  and  326  are provided to keep the conveyor in place and permitting one of the pulleys  324  and  326  to be a driven pulley. 
       FIGS. 15 and 16  show an alternate embodiment  400  that is essentially like embodiment  200  in  FIG. 13 , except that the rear sprocket is the same as the front sprocket, one being driven and the other one being an idler sprocket. The alternate embodiment  400  has a front sprocket  424  that is like sprocket  24  of  FIGS. 1-10 , except that it is wider. Also, there are two auxiliary feed rollers  440  that are like auxiliary feed roller  40  of  FIG. 5 , but relatively narrower. So logs on the feed table  411  would be moved by the chain  412  towards the lugs  424   c  on roller  424  and those lugs  424   c , in conjunction with the lugs on auxiliary feed rollers  440  will push the log towards the main feed roller and towards the cutter drum  14 . 
     The above described embodiments are the preferred embodiments, but this invention is not limited thereto. It is, therefore, apparent that many modifications and variations of the present invention are possible in light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.