Comminuting apparatus

Abstract

The comminution of solid materials, such as stumps and wood waste, into particulate form is accomplished by introducing the material to be comminuted into a tub. The tub is rotated to induce a circular motion to the material. Simultaneously, a disk positioned at the bottom of the tub is rotated, preferably in the opposite direction to the tub, in a plane parallel to the tub bottom. The disk has teeth thereon that impact the material in the tub. A screening means at the bottom of the tub is sized to keep the material in the tub until it reaches a desired particle size, at which time the particles can leave the tub through the screening means and enter a collection chamber. The particles are removed from the collection chamber by being entrained in an airstream that passes adjacent an opening in the collection chamber. Preferably, the teeth in the disk are individually replaceable and are symmetric so that once one side is worn the tooth can be reversed in its mount and used again.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows: 
     
       1. A comminuter for reducing solid material to particulate form comprising: a frame;   a tub rotatably mounted on said frame, said tub including a cylindrical sidewall and a bottom wall consisting of an annular portion affixed to said sidewall and perpendicular thereto, said a central, circular portion mounted on said frame and separated from said annular portion but lying in the same plane as the annular portion;   a first drive means mounted on said frame and drivingly connected to said sidewall and said annular port for rotating a sidewall and said annular portion in a first direction;   a disk mounted within said tub, in a plane parallel to and spaced above the plane of said annular portion and said circular portion;   a drive motor mounted on said frame and drivingly coupled to said disk to rotate said disk in a second direction; and   a plurality of tooth members mounted on said disk and projecting from said disk into said tub, the orientation of each tooth member being individually adjustable independent of the orientation of each other tooth member.   
     
     
       2. The comminuter of claim 1, further including transmission means associated with said first dive means for reversing the direction of rotation of said tub. 
     
     
       3. The comminuter of claim 1, further including transmission means associated with said drive motor and operable to reverse the direction of rotation of said disk. 
     
     
       4. The comminuter of claim 1, wherein said second direction is opposite said first direction. 
     
     
       5. The comminuter of claim 1, wherein the axis of rotation of said disk is offset from the axis of rotation of said tub. 
     
     
       6. The comminuter of claim 1, wherein said frame is mounted on wheels to provide portability of said comminuter. 
     
     
       7. The comminuter of claim 1, further including tooth-mounting means associated with each of said teeth in said disk for mounting said teeth at varying angles of projection from said disk, at least some of said teeth pointing downwardly toward the bottom of said tub, said downwardly pointing teeth scraping the bottom wall of said tub. 
     
     
       8. The comminuter of claim 7, wherein said tooth-mounting means includes a mounting beam having a slot formed therein, said tooth being substantially planar and resting in said slot, a first and second bias wedge mounted in said slot on opposite sides of said planar tooth, said bias wedges of a size such that they exert a twisting force on said tooth to deform said tooth and provide an interference fit of said tooth in said slot. 
     
     
       9. The comminuter of claim 8, wherein each of said teeth is symmetrical with first and second material-contacting edges, respectively, located on each end thereof, said mounting means holding said teeth so that only said first material-contacting edge is exposed and said second material-contacting edge is protected such that, when said first material-contacting edge is worn, said tooth can be rotated 180 degrees and its second material contacting edge exposed. 
     
     
       10. The comminuter of claim 1, wherein said first drive means includes at least three radially flexible wheels mounted exteriorly to said sidewall and spaced about said sidewall and in contact with the exterior of said sidewall to provide a centering force on said tub as it is driven by said radially flexible wheels, said radially flexible wheels constructed to permit some lateral movement of said tub so as to absorb the shock caused by the entry of heavy objects into said tub. 
     
     
       11. The comminuter of claim 10, wherein said radially flexible wheels act as a clutch means to provide a predetermined clutch force that permits said drive means to drive said sidewall, but is limited so that said drive means slips if said sidewall becomes jammed and unable to rotate. 
     
     
       12. The comminuter of claim 11, wherein said radially flexible wheels comprise pneumatic tires mounted on rims and inflated to a predetermined pressure to come in contact with said sidewall with said clutch force. 
     
     
       13. The comminuter of claim 1, further including screening means mounted in said annular portion of said bottom wall of said tub for allowing the exit of material of a predetermined size from said tub, said screening means comprised of a plurality of segments cooperatively mounted on said tub to form said annular portion of said bottom wall. 
     
     
       14. The comminuter of claim 13, including discharge means in communication with said screening means for moving said particles of material from said tub. 
     
     
       15. The comminuter of claim 13, further including a collection chamber located below said bottom wall of said tub in communication with said screening means to receive the particles from said tub that pass through said screening means. 
     
     
       16. The comminuter of claim 15, wherein said collection chamber has an opening for removal of said particles. 
     
     
       17. The comminuter of claim 16, further including a tube positioned exteriorly to said tub, said tube having a port formed in a sidewall thereof in register with the opening in the collection chamber and further including a blower connected to one end of said tube to provide a flow of air through said tube. 
     
     
       18. The comminuter of claim 17, wherein said tube has a constriction therein adjacent said port. .Iadd. 
     
     
       19.  A comminuter for reducing solid material to particulate form comprising: a frame;   a tub including a cylindrical sidewall and a bottom disposed across an end of said sidewall, said sidewall being rotatably mounted on said frame;   a first drive means mounted on said frame and drivingly connected to said sidewall for rotating said sidewall in a first direction;   a disk rotatably mounted within said tub adjacent said bottom of said tub;   a drive motor mounted on said frame and drivingly coupled to said disk to rotate said disk in a second direction; and   a plurality of teeth mounted on said disk and protecting from said disk into said tub, the orientation of each tooth being individually adjustable independent of the orientation of each other tooth. .Iaddend..Iadd.   
     
     
       20.  The comminuter of claim 19, wherein said second direction is opposite said first direction. .Iaddend..Iadd.21. The comminuter of claim 19, wherein the axis of rotation of said disk is offset from the axis of rotation of said sidewall. .Iaddend..Iadd.22. A comminuter tooth for use in a comminuter for reducing solid material to particular form, the comminuter including a mounting block assembly defining a tooth receiving slot, the slot defining first and second bearing surfaces, the tooth comprising: plate member including a cutting edge and first and second sides, said plate member being sized for mounting in the slot in the comminuter mounting block assembly such that the plate member can be driven into the slot with the first and second sides of the plate member bearing on the first and second bearing surfaces of the slot, the first and second bearing surfaces of the slot having a contour that induces a twist in the plate member and securely retains the plate member within the slot. .Iaddend..Iadd.23. The comminuter tooth of claim 22, further comprising a contact surface for positively ending an opposing surface external to said tooth to further maintain said plate member in the slot. .Iaddend..Iadd.24. The comminuter tooth of claim 22, wherein the plate member is contoured to bear against and be twisted by a bias wedge assembled within the slot of the comminuter mounting block assembly. .Iaddend..Iadd.25. A comminuter tooth and mounting block combination for use in a comminuter for reducing solid material to particulate form, the combination comprising:   a tooth plate member;   a mounting block having a slot formed therein, said slot sized for receiving said tooth plate member; and   a first bias wedge assembled within said slot;   wherein said tooth plate member may be inserted into said slot with the tooth plate member contacting said assembled bias wedge to induce a twisting force on said tooth plate member to deform said tooth plate member, wherein an interference fit of said tooth plate member in said   
     
     
        slot is achieved. .Iaddend..Iadd.26.  The comminuter tooth and mounting block combination of claim 25, wherein the mounting block defines first and second bearing surfaces for opposing the forces imparted by the tooth resulting form being twisted, thereby providing the interference fit of said tooth in said slot. .Iaddend..Iadd.27. The comminuter tooth and mounting block of claim 25, further comprising a second bias wedge assembled within said slot to oppose said first bias wedge. .Iaddend..Iadd.28. The comminuter tooth and mounting block combination of claim 25, wherein the tooth defines a contact surface for positively engaging an opposing surface external to the tooth. .Iaddend..Iadd.29. The comminuter tooth and mounting block combination of claim 25, wherein said first bias wedge is integrally secured to the mounting block. .Iaddend..Iadd.30. A comminuter for reducing solid material to particulate form comprising: a frame;   a tub including a cylindrical sidewall and a bottom disposed across an end of said sidewall, said sidewall being rotatably mounted on said frame;   a motor mounted on said frame and driving connected to said sidewall for rotating said sidewall in a first direction;   a disk rotatably mounted within said tub with a plane of rotation adjacent said bottom of said tub;   a drive motor mounted on said frame and drivingly coupled to said disk to rotate said disk in a second direction; and   a plurality of teeth mounted on said disk and projecting from said disk   
     
     
        into said tub. .Iaddend..Iadd.31.  The comminuter of claim 30, further comprising transmission means associated with said motor for reversing the direction of rotation of said tub. .Iaddend..Iadd.32. The comminuter of claim 30, wherein said second direction is opposite said first direction. .Iaddend..Iadd.33. The comminuter of claim 30, wherein the axis of rotation of said disk is offset from the axis of rotation of said sidewall. .Iaddend..Iadd.34. The comminuter of claim 30, wherein the plurality of teeth are replaceable part from said disk. .Iaddend..Iadd.35. A comminuter for reducing solid material to particulate form comprising: a frame;   a tub including a cylindrical sidewall and a bottom disposed across an end of said sidewall, said sidewall being rotatably mounted on said frame;   a motor mounted on said frame and drivingly connected to said sidewall for rotating said sidewall in a first direction;   a disk rotatably mounted within said tub with a plane of rotation adjacent said bottom of said tub;   a drive motor mounted on said frame and drivingly coupled to said disk to rotate said disk in a second direction; and   a plurality of teeth mounted on said disk and projecting from said disk at a plurality of dispositions into said tub. .Iaddend..Iadd.36. The comminuter of claim 35, wherein said plurality of teeth projecting from said disk at said plurality of dispositions is comprised of a plurality of teeth projecting from said disk at various angles with relation to a surface of the disk. .Iaddend.