Solid material comminution or disintegration – Apparatus – Rotary striking member with feed or discharge conveyor or...
Reexamination Certificate
1998-05-01
2001-10-09
Rosenbaum, Mark (Department: 3725)
Solid material comminution or disintegration
Apparatus
Rotary striking member with feed or discharge conveyor or...
C241S189100, C241S200000
Reexamination Certificate
active
06299082
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a waste processing machine and, more specifically, to a waste processing machine incorporating a rotor having multiple cutting or shredding tools pivotally mounted thereon.
2. Description of the Related Art
A variety of machines have been developed to chip, cut, grind, or otherwise reduce waste products. Currently, four types of equipment are generally used for this purpose: chippers (disk and drum types), hammer mills, hogs, and shredders.
Chippers are generally constructed around a rotating disk or drum and a plurality of blades are mounted to the disk or drum. As the drum rotates, the blades sheer the product to be reduced into chips. Chippers are ideally suited to chip logs and trees as well as small brush. A significant disadvantage for chippers is that they require reasonably “clean” wood in order for the chipper knives to remain sharp. Any foreign materials such as nails, spikes, rocks, and sand will quickly dull the knife cutting edge. For this reason, chippers are not suited for reducing wood waste products such as pallets, tree stumps, and other waste products in which wood, dirt, and other foreign objects would be found.
Hammer mills are generally constructed around a rotating shaft that has a plurality of disks provided thereon. A plurality of free-swinging hammers are typically attached to the periphery of each disk. With this structure, a portion of the kinetic energy stored in the rotating disks is transferred to the wood products through the rotating hammers. The hammers strike the product in order to reduce it. A hammer mill will break up pallets, paper products, construction materials, and small tree branches. Because the swinging hammers do not use a sharp edge to cut the waste material, the hammer mill is more suited for processing “dirty” waste products. A hammer mill also has the advantage that the rotatable hammers will recoil backwardly if the hammer cannot break the material on impact. One significant problem with hammer mills is the wear of the hammers over a relatively short period of operation in reducing “dirty” products which include materials such as nails, dirt, sand, metal, and the like.
Hogs are similar to hammer mills except the hammers provided on the hogs are rigidly secured to the periphery of the rotating disks. The hog hammer assembly suffers from the disadvantage that the hammers directly mounted to the rotating disk will often be damaged when the hog hammers strike a non-grindable object.
Chippers, hammer mills, and hogs all operate at a high speed of rotation. Shredders operate at a much slower speed of rotation and therefore are more suited for processing metals and rubber products.
The waste processors known in the prior art suffer from several problems. First, none of the waste processors known in the prior art can adequately process dirty material without resulting in undue wear on the machine or frequent clogging or jamming of the machine. Another significant problem for the known processing machine is the time involved in changing the processing tools, it takes several hours to change the processing tools such as cutting knives or hammers for these machines. When this problem is coupled with the unacceptably fast wear of the processing tool, then the operating time of the machine is dramatically reduced creating an unacceptably inefficient machine.
SUMMARY OF THE INVENTION
The waste processing machine according to the invention overcomes the problems of the prior art by incorporating means which can reduce a large variety of dirty products, including product contaminated with non-grindables. In addition, the cutting tools are adapted to have a long-wear life as compared to the prior art and can be quickly changed in the event that the tool fails or is worn out.
The invention centers around a rotor assembly which is provided inside a waste processing or waste reducing machine. The rotor assembly is rotationally mounted inside a housing. The rotor assembly has multiple processing tools mounted to the external surface of the rotor. Preferably, the processing tools are staggered about the periphery so that a small, limited number of processing tools contact a line passing parallel to the axis of rotation of the rotor at any one point in time. Preferably, the processing tools are provided on the surface in multiple, helical patterns sweeping around at least part of the rotor. Depending upon the sweep of the helical pattern, two or more cutting tools might be aligned to strike the same point on the line parallel to the axis of rotation of the rotor during each revolution of the rotor.
The processing tools are adapted to be modified for a variety of different uses and are easily repaired or replaced. Preferably, each processing tool is pivotally mounted to a pair of upstanding arms provided on the exterior surface of the rotor. The processing tool is easily adapted for a wide variety of applications. For example, cutting, shredding, or chipping tools or a combination thereof can be mounted to the processing tool, depending upon the particular waste reducing or processing application.
Preferably, each processing tool is C-shaped wherein the leading arm of the C-shape operates as a depth-limiting guide for the cutting, chipping, or shredding tool provided on the other of the two arms. Through the combination of staggering the processing tools about the periphery of the rotor and limiting the depth of cut for each tool, the waste reducing system according to the invention can accommodate dirty waste products without jamming or clogging. More importantly, the anvil, which is typically incorporated in waste reducing systems in the prior art, can be eliminated because the force exerted on the waste product at any one point in time is relatively small. In the preferred embodiment, there is no anvil incorporated. The waste product is supported solely by a conveyor positioned a short distance away from the rotor assembly. By the elimination of the anvil, clogging problems have been largely eliminated.
Another aspect of the invention is a unique structure for mounting the rotor tube to a support shaft. A jig is provided having supports extending radially outwardly therefrom wherein the end surfaces of the supports are tapered. The jig is inserted so that the tapered end of the braces contacts the interior surface of the tube and effectively centers itself on the tube interior. Next, a shaft is inserted into the jig and clamped thereon. Finally, multiple brace members are welded to the interior of the tube and the shaft. Preferably, the braces are mounted tangentially to the surface of the tube. With this structure, the braces act as a spring to absorb unexpected shock experienced by the rotor assembly during the waste reducing process.
The invention also centers around means for providing a secondary waste reducing or cutting operation. A basin is provided immediately below the rotor for collecting the pieces of material being reduced. An anvil is provided at the top of the basin immediately adjacent the rotor assembly. Augers are provided in the basin to urge the waste material upwardly toward the anvil and rotor assembly. As the level of material builds in the basin, eventually, the material will be brought into contact with the rotor, and the anvil and will be further reduced.
Another element of the invention is a novel screen provided at the discharge of the rotor assembly. Typically, screens are used to provide a limit on the size of waste product exiting the system. The screen according to the invention provides the additional function of disrupting the boundary layer surrounding the rotor and stripping any entrapped material from the boundary layer. The screen accomplishes this function by creating an angled surface on the surfaces of the screen which extend parallel to the longitudinal axis of the rotor. Preferably, the angle is approximately 32° from the radius of the rotor.
REFERENCES:
patent: 190675 (1877-05-01), Gaines
patent: 399025 (1889-03-01), Evan
Bliss McGlynn & Nolan, P.C.
Rosenbaum Mark
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