Abstract:
A brush chipper that enables easy and ready access to frequently maintained areas of the chipper comprises a chipper-knife assembly, a feed-roller assembly, and a sliding apparatus that allows the feed-roller assembly to move away from the chipper-knife assembly. This sliding apparatus, preferably, includes at least one track and at least one friction-reducing apparatus. The brush chipper preferably includes a chipper-knife assembly that comprises a knife with at least one threaded opening for attaching the knife to a support. To attach the knife to the support, a bolt threads through the support to secure the knife. The bolt includes a head and a stem, and the support is positioned between the knife and the head of the bolt.

Description:
FIELD OF THE INVENTION 
     The present invention relates to the field of general maintenance. 
     BACKGROUND OF THE INVENTION 
     Many industrial, commercial, and household applications require the breaking up of relatively large objects into smaller pieces. This reduction process is variously referred to as cutting, chipping, shredding, mulching, or grinding, depending in part on the size of the end product. Cutting and chipping are historically accomplished by chippers using relatively few chipper knives mounted directly onto a rotating disc and a bed knife. The chippers can produce pieces ranging up to about ¾ to 1½ inches in size. 
     One of the major issues with respect to the design of such devices is maintenance. Maintenance and adjustment of chipper and bed knives can be extremely cumbersome. In many chippers, a team of two men is required to change the chipper knives, by working through holes in the side of the chipper body. Long feeler gauges must be used to adjust the gap between the chipper knives and the bed knives. 
     Another issue is the design and maintenance of the feed rollers. Traditionally, dirt and trash are carried into the chipper with the in-feeding of the brush and wood. The dirt usually falls into the lower feed roller. If not cleaned out, the dirt will lock up the feed roller such that it cannot rotate. In addition, the chipper knives are mounted to the rotating disc, usually, using ½ inch size Allen bolts with flat head sockets and a nut. The holes for the Allen bolts are exposed to the feed material and are easily plugged with debris. The debris strips out the holes making it difficult to change the knives. 
     To access these various components and areas, some manufacturers of the disk-style machines often hinge the upper half or quarter of the chipper body to service the knives. Such machines include the Model 1230 Chipper manufactured by Vermeer and the Model 90 Brush Bandit manufactured by Bandit. The bed knife, however, remains difficult to adjust. Some other manufacturers such as Carlenburg for Mittsonmurrel Drum Machines and Gravely Disk Chippers facilitate the servicing of knives by hinging the feed hopper or sliding the upper feed roller vertically in a slide with weights or spring down pressure. In many of these systems, replacing the feed rollers requires one to crawl inside the machine and awkwardly perform the replacement. Morey, U.S. Pat. No. 5,005,620 discloses an upper feed roller pivoted from the chipper drum centerline (called the pivoted down stream). Houston, U.S. Pat. No. 4,390,132 discloses a trailing arm that is pivoted from a point above the feed path. A hydraulic cylinder and a compression spring force the engagement with the tree (feed stock). To reduce the frequency of required access, most manufacturers of chippers with lower feed rollers simply place an auxiliary frame or compartment that traps the dirt and debris. 
     SUMMARY OF THE INVENTION 
     The present invention is directed, in a first aspect, to a brush chipper in which access to frequently maintained areas of the chipper is facilitated. According to the one embodiment of the invention, the chipper comprises a chipper-knife assembly, a feed-roller assembly, and a sliding apparatus that permits a part or the whole feed-roller assembly to move away from the chipper-knife assembly. This sliding apparatus preferably includes at least one track and at least one friction-reducing apparatus such as a sliding roller or a bearing. 
     Another aspect of the invention is directed to a mounting for the chipper-knife assembly. In a preferred embodiment, the chipper-knife assembly comprises a knife with at least one threaded opening attached to a support. To attach the knife, a bolt passes through the support to thread into the knife. The bolt can include a head and a stem, and the support is positioned between the knife and the head of the bolt. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     These and other aspects of the present invention will become better understood through a consideration of the following description taken in conjunction with the drawings in which: 
     FIG. 1 is a diagram of an exploded perspective view of a chipper disc and attachments according to one embodiment of the present invention. 
     FIG. 2 is a diagram of a close-up side view of a chipper-knife section attached to the disc of FIG.  1 . 
     FIG. 3 is a diagram of an exploded view of a chipper-housing assembly for a disk chipper such as that depicted in FIG.  1 . 
     FIG. 4 is a diagram of an exploded perspective view of an upper feed-roller arm and housing weldment according to one embodiment of the present invention. 
     FIG. 5 is a diagram of a side view of a brush chipper according to one embodiment of the present invention where the chipper housing is separated from the feed-roller housing. 
     FIG. 6 is a diagram of a side view of a brush chipper according to one embodiment of the present invention where the chipper housing is adjacent to the feed-roller housing. 
     FIG. 7 is a diagram of a close-up section view of a sliding apparatus used for separating the feed-roller housing from the chipper housing assembly. 
     FIG. 8 is a diagram of a close-up perspective view of a brush where the chipper-knife assembly is inside the chipper housing assembly and is separated from the feed-roller housing. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIG. 1 shows a disc  2  with knife channels  4 , and chipper knives  6 , fan assemblies  8 , and pulley belt drive  10  attached to the disc  2 . The disc  2  is preferably about 42″ in diameter, 2″ thick, comprised of A-36 steel, and is made to rotate about an axle  12  at about 1100 rotations per minute (rpm) by a motor (not shown) attached to the pulley belt drive  10 . Knife channels  4  communicate across the disc  2 , thereby permitting chips and debris to pass through the disc  2  and out of a discharge tube  76  (See FIG.  5 ). 
     Each fan assembly  8  shown in FIG. 1 preferably includes a base  14 , a fan blade  16  and a fence  18 . Bases  14  are attached to the disc  2  with bolts  20  and lock nuts  22 . Each fan blade  8  is preferably attached to the disc  2  through one of the bases  14  and are preferably oriented approximately twelve degrees off radial with respect to the axle  12  to encourage radial air flow. The fences  18  assist in holding air and light material to the fan blades  16  and further encourage radial airflow. A preferred embodiment has four fan assemblies  8 , but fewer or greater number of fan assemblies  8  can also be accommodated on the disc  2 . 
     In FIGS. 1 and 2, chipper knives  6  are positioned as an assembly of components on the disc  2 . Each chipper knife  6  preferably has two cutting edges to make them reversible. Each chipper knife  6  is preferably manufactured to be expendable or disposable such that once both edges are dulled, it is easily replaced. Chipper knives  6  are preferably attached to the disc  2  by bolts  26  and lock washers  27 . Each bolt  26  is made up of a head  28 , preferably a ¾″ hex head and a threaded stem  29 . The bolts  26  hold the knives  6  by passing through the disc  2  from the backside of the disc  2  to thread into the knives  6 . Each knife  6  includes at least one threaded opening  31  for inserting with a bolt  26 . Preferably, the threaded openings  31  are located in a middle section of the knives  6 . Thus, the chipper knives  6  are effectively positioned on a side of the disc  2 , which supports the knives  6 . Likewise, the bed knife  34  includes at least one threaded opening for inserting a bolt  40 . The bolt is threaded through the bed knife  34  from the back side of a bed knife holder  36  or other support. 
     In this type of construction, the heads of the bolts  40 ,  26  are neither directly exposed nor impacted with the debris. This effectively prevents stripping out the hexagon-shape head of the bolts  40 ,  26  making the knives  6  easy to replace. 
     FIG. 3 shows the chipper housing assembly that houses the disc  2  and the chipper-knives assembly. This chipper housing assembly includes the housing for the disc  2 , an attached lower feed roller  32 , and the bed knife  34 . The housing is constructed in two sections, a cover weldment  38  and a body weldment  30 . Integrated into the body weldment  30  is a bed knife holder  36 . The bed knife  34  is then secured to the holder  36  with bolts  40  as shown in both FIGS. 2 and 3. The bed knife  34  is adjusted to preferably have a 0.090-inch gap between it  34  and the closest chipper knife  6  on the disc  2 . Integral to the body weldment  30  is a lower feed roller chamber  42 . During rotation of the disc  2 , the fan blades  8  of the disc  2  vacuum trash and debris into the disc housing section of the body weldment  30  that enters the lower feed roller chamber  42 . Because of the integrated design of the body weldment  30  and the lower feed roller chamber  42 , the vacuuming of the lower feed roller chamber  42  preferably takes place through the opening  43  in the disc housing. 
     The lower feed roller  32  reduces the friction of the incoming wood and brush, which drop loose debris. The debris then passes through the opening  43  in the disc housing to be blown out of the discharge tube  76  (See FIG. 5) by the fan blades  8  on the revolving disc  2 . The lower feed roller  32  is held in place by bearings  44  attached to the lower feed roller chamber  42 . The lower feed roller  32  preferably has an 8-inch diameter and is 14inches wide. Preferably, a 1½ inch diameter shaft  46  extending beyond the lower feedroller&#39;s width and providing the bearings&#39; point of support and rotation for the lower feed roller  32 , is integrated with the roller  32  itself. The lower feed roller  32  is thereby supported within the chamber  42  for rotation about a generally horizontal axis. The lower feed roller  32  preferably includes rows of low profile cleats  48  running along its width. Moreover, the lower feed roller  32  is preferably mounted close to the bed knife  34  and the disc  2 . Finally, lower feed roller  32  is preferably powered by a 16 cubic inch at 6,329 in.-lbs. torque hydraulic motor  50  allowing for reverse or forward rotation. 
     FIG. 4 depicts an embodiment of a assembly for the upper feed roller  52 . The upper and lower feed rollers  52 ,  32  receive the input material from the in-feed hopper  72 . (See FIG. 5.) The assembly includes an upper feed roller  52 , an upper feed roller shaft  54 , an upper feed roll weldment  56 , a trailing arms assembly  58 , and hydraulic motor  60 . The upper feed roller  52  is positioned above the lower feed roller  32  and is rotatably supported by the trailing arm assembly  58 . The pivot points  61  for the upper feed roller  52  on the arm assembly  58  are on the sides of the weldment  56 . Bearings  70  provide support to the trailing arm assembly  58  allowing for pivoting of the assembly  58  and upper feed roller  52 . The arms&#39; length of the trailing arm assembly  58  and its pivot point are positioned so as to insure a ratchet-type action when the roller  52  is in operation. This ratchet-type action naturally increases the bite down pressure on in-feeding wood and debris. The upper feed roller  52  preferably has the same 14-inch width as the lower feed roller  32 , and preferably has a diameter of 12 inches. Rather than cleats  48 , the upper feed roller  52  has preferably ten sharpened blades  62 , each having the same width as the roller  52  itself. The shaft  54  of the upper feed roller  52  preferably has a length that exceeds the width of the upper feed roller  52 . The shaft  54  runs through the center of the upper feed roller  52 , and is attached to the upper feed roller  52  with nuts  64  and bolts  66 . The upper feed roll weldment  56  covers the upper feed roller  52  and provides a track  68  for movement of the upper feed roller  52  caused by the pivoting of the trailing arms assembly  58 . The upper feed roller  52  is preferably independently powered by a 28 cubic inch at 11,269 in.-lbs. torque hydraulic motor  60  allowing for forward or reverse rotation. A feed-roller housing  69  houses the upper feed-roller assembly. 
     FIG. 5 shows a side-view drawing of the brush chipper with the feed-roller housing  69  containing the upper feed roller  52  assembly slid away and separated from the chipper housing assembly. Because of a sliding apparatus mounted underneath the feed roller housing, one person may easily separate the feed-roller housing  69  from the chipper housing assembly. Once separated, the chipper knives  6 , the bed knife  34 , the knife holders  24 , the upper and lower feed rollers  52 ,  32  are easily accessed for adjustment or replacement. (See FIG. 8) To operate the brush chipper, the user then slides the feed roller housing back adjacent to the chipper housing assembly as in FIG.  6 . Locks and safety switches, which are already known in the art, may also be employed to ensure that the feed-roller housing does not slide open during operation or that the brush chipper engine shuts off when the feed-roller housing is slid open. 
     The sliding apparatus preferably comprises a set of parallel tracks or guides and a friction-reducing apparatus underneath the feed-roller housing  69 . FIGS. 7 and 8 depict one embodiment of a sliding apparatus using a track and roller system. The track and roller system includes two parallel tracks  80  running from the chipper housing assembly and underneath the feed-roller housing. Sliding rollers  82 , preferably numbering four with two rollers on each side of a metal plate  86 , are screwed onto the side bars  84  of the metal plate  86  and roll along the grooves  88  provided inside the tracks  80 . The metal plate  86  attaches to the underside of the feed-roller housing such that the feed-roller housing rolls toward or away from the chipper housing. The sliding rollers  82 , alternatively, are designed as bearings instead. It is understood that the track or guide and the friction-reducing apparatus can be interchangeably located underneath the feed-roller housing. 
     While specific embodiments of this invention have been disclosed and described, it would be apparent to those skilled in the art that the invention can be modified in arrangement and detail without departing from such principles. As such it should be recognized that the detailed embodiment is illustrative only and should not be taken as limiting the scope of the invention. Rather, the invention is not to be restricted except within the scope and spirit of the following claims and equivalents thereto.