US3735933A - Disposal machine for cuttings or the like - Google Patents

Abstract

Apparatus for the disposal of cuttings or the like adapted to cut, tear and compress such cuttings to prepare the same for composting, involving a pair of adjacent parallel disposed contra rotating rotors, each of the rotors having circumferentially spaced blades at a rake angle in the direction of rotation, with the blades of one overlapping those of the other rotor during rotation, and means for guiding material to said rotors at the location where the blades of each rotor approach the blades of the other.

Description

lJ'nite States Patent 11 1 1111 3 735 933 fiampbell 1 1 May 29, 1973 [54] DISPOSAL MACHINE FOR CUTTINGS 1,233,514 7/1917 Scott ..241/243 x OR THE L 1,007,391 10/1911 Root ..241 293 x 1,713,487 5/1929 Torrance ..241/227 Inventor: James Samuel Campbell, 74 py 3,429,350, 2/1969 Otto ..241 3oo x Hollow Lane, Orinda, Calif.

Primary ExaminerGranville Y. Custer, Jr. [22] Flled' 1971 Att0rney-Edward Brosler [21] Appl. No.: 130,093

[57] ABSTRACT [52] us. Cl. ..241/236, 241/300, 241/101.7 App r for the disposal of i g r the li [51] llnt. Cl. ..B02c 13/06 adapted to Cut, tear and compress Such Cuttings to [58] Field of Search ..241/191, 195, 236, Prepare the Same for composting, involving a P of 241 /243 293, 294 227 300; 83/698. adjacent parallel disposed contra rotating rotors, each 6 5. 5 30/343, of the rotors having circumferentially spaced blades at a rake angle in the direction of rotation, with the 5 6] References Cited blades of one overlapping those of the other rotor during rotation, and means for guiding material to said ro- UNITED STATES PATENTS tors at the location where the blades of each rotor approach the blades of the other. 733,454 7/1903 Bloom ..241/236 X 2,357,088 8/1944 Curtis ..29/103 4 Claims, 6 Drawing Figures I 14 1 m l -122144 444 O 7 I 6 0-11 L u u Patented May 29, 1973 3,735,933

5 Sheets-Sheet l N to 1- 0 r r 4 5 m IF x E i W I /m in r 6 a 5 E 7 W I /II' J H m I I I I I r (O I/ "II /IO N w I INVENTOR. JAMES SAMUEL CAMPBELL ATTORNEY Patented May 29, 1973 3,735,933

5 Sheets-Sheet 2 w j z I LO (Q w lP II u m d N I L T o 1 E 2 2 II u. mi g :0 T!- (O I Y 71.

INVENTOR. JAMES SAMUEL CAMPBELL ATTORNEY Patented May 29, 1973 3,735,933

5 Sheets-Sheet 5 INVENTOR. JAMES SAMUEL CAMPBELL ATTORNEY Patented May 29, 1973 3,735,933

5 Sheets-Sheet 4.

INVENTOR. JAMES SAMUEL CAMPBELL W QM ATTORNEY Patented May 29, 1973 3,735,933

ATTORNEY DISPOSAL MACHINE FOR CU'ITINGS OR THE LIKE My invention relates to apparatus for the disposal of cuttings or the like, for composting or other appropriate treatment.

The ideal product should not only comprise small pieces, but of even greater importance, is the desirability that such pieces be so mutilated as to expose substantial amount of internal'fiber structure.

Various types of equipment are available for the purpose of disposing of cuttings but each falls short in one respect or another.

Among the objects of my invention are:

1. To provide a novel and improved apparatus for disposal of cuttings or the like by reducing such cuttings to a condition more suitable for composting or other appropriate treatment;

2. To provide a novel and improved apparatus for reducing cuttings or the like to small pieces having a high percentage of exposed internal fibers;

3. To provide a novel and improved apparatus which will reduce and mutilate cuttings whether dry or fresh;

4. To provide a novel and improved apparatus for reducing cuttings or the like at an extremely fast rate.

Additional objects of my invention will be brought out in the following description of a preferred embodiment of the same, taken in conjunction with the accompanying drawings wherein:

FIG. 1 is a side view in elevation, partly in section, of apparatus embodying the present invention;

FIG. 2 is a plan view, partly in section, of the apparatus of FIG. 1;

FIG. 3 is an end view in elevation, partly in section, of the apparatus of FIG. 1;

FIG. 4 is a view corresponding to that of FIG. 3, but depicting a modification of the apparatus of FIG. 1;

FIGS. 5 and 6 are enlarged views illustrating a pair of rotatab ly positioned rotor assemblies, wherein are incorporated important features of the present invention.

Referring to the drawings for details of the invention in its preferred form, the heart of the invention resides in the pair of identical rotor assemblies 1, 3 depicted in detail in FIGS. 5 and 6. These rotor assemblies are mounted on parallel shafts 5, 6 supported in appropriate bearings 7 installed in the end walls 9, l1 and a partition 13 of a generally rectangular housing 15. The

partition divides the housing into two chambers 17, 19, the rotor assemblies being located in the one chamber 17.

One of the shafts 5, constitutes a drive shaft, which extends beyond the one end wall 11 of the housing, for coupling to a drive motor 21 which may be either electrical or of the internal combustion type. The other shaft 7 constitutes a driven shaft, which is coupled to the drive shaft in the second chamber 19 of the housing, by means of a pair of one to one ratio gears 23. The housing chamber 17 which contains the rotor assemblies, is left bottomless, while the second chamber 19 is provided with a floor to form a receptacle for oil in which the gears may rotate for lubrication.

The upper rim of the housing is spanned by appropriate chamber covers 27, 29 bolted thereon, the cover 29 over the rotor assemblies, including a vertically disposed hopper 31 for the feeding of cuttings to the rotor assemblies.

2 The housing, with its rotor assemblies and gear drive, may be mounted for portability, on four legs, in which case, the two front legs 35 will each include an offset providing a horizontal intermediate section 3'? to form part of a frame 39 on which to mount the drive motor 21. Wheels 41 attached to the front legs will provide for mobility, while each of the rear legs 45 will preferably terminate in a flange tip $7 to provide firm support in soft ground.

Appropriate handles 49 extending rearwardly from the housing, will facilitate the maneuvering of the apparatus.

As previously indicated, the heart of the present invention resides in the design and construction of the rotor assemblies 1, 3, the details of which have been depicted in FIGS. 5 and 6 of the drawings to which reference will now be made.

Each rotor assembly includes a cylindrical core 51 perferably of metal, with a plurality of blades 53 extending longitudinally of the core and distributed equally about the periphery thereof, such blades being anchored to the core at a positive rake angle 55 with a clearance angle which contributes to the cutting action of the blades, the rake angle being that angle which a blade makes with a radius from the center of the core to the tip of the blade. With 12 blades to a rotor assembly, I have found an efficient rake angle to be of the order of 20, a clearance angle of the order of 10.

While these blades may be assembled to the core by casting them into the core, this would leave them permanently and incapable of being replaced in, the event of breakage, or other damage thereto which might render a blade useless. In such case, the entire rotor assembly would have to be replaced in order to correct for such a situation.

I have found that, by forming appropriate slots 57 in the core, the blades may be adequately anchored in such slots through the use of a suitable adhesive such as an epoxy, which is a termo setting plastic. Should it be necessary to remove a blade, the application of a torch to that particular blade will weaken and burn out the adhesive and permit the blade to be driven from its slot.

In lieu of a thermo setting plastic, one can use a thermo plastic adhesive which will soften with application of heat and permit removal of a blade.

Additional adhesive security in the anchoring of a blade may be realized by roughing the surfaces to which the adhesive is applied, or by forming minor longitudinal ridges or score lines in such surfaces.

With the rotor assemblies so constructed, they are mounted on their respective shafts for counter rotation and with the blades of one entering the spaces between the blades of the other as they approach each other during rotation.

Of considerable importance to the present invention is the action of such blades upon a branch 59 or equivalent cutting, fed to the contra rotating rotor assemblies, in the region where the blades of one assembly approach the blades of the other assembly.

The first thing that happens, is that one of the blades will engage the proximate end of the branch being fed into the apparatus and immediately initiate a self feeding operation, to be continued by the next approaching blade of the opposing rotor assembly, and so on. The result is that such branch will automatically be fed into the apparatus with amazing speed which will be proportional to the rotational speed of the rotor assemblies, which may be of the order of 3,600 RPM. If the distance from the center of the core to the tip of a blade be of the order of 2 /4 inches, it can be calculated that with a rotational speed of 3,600 RPM, the linear feed rate would be of the order of 71 feet per second.

Now, considering the movement of one blade of one of the rotor assemblies with respect to a proximate blade of the other rotor assembly and its effect on the branch being feed thereto, it is important to note that as these blades approach each other, they reach a minimum distance between them, following which, the distance increases while still in the path of movement of such branch between the rotor assemblies.

It is to be noted that during this portion of the movement of the two blades under consideration, each will have a firm grip on the branch, and will be in the process of cutting deeper and deeper into such branch. Consequently, with such a firm grip, the increasing of the distance between these proximate blades will impart a strong tensioning force to that portion of the branch between the rotor assemblies, thereby exerting terrific tearing stresses thereon.

Thus, for example,with the tip of each blade at a radial distance of 2% inches from the center of the core, and with the cores spacedapart a distance of /16 of an inch at their peripheries,the closest approach between proximate blades of opposing rotor assemblies, will be 0.54 inches. By the time such blades span the line joining the centers of the cores, the distance between the tips of the same blades will have increased to 0.754 inches.

In the mean time, and during the application of such forces, the branch in question will be exposed to severe bending and compression forces, it being noted in this connection, that the blade tips in the embodiment specifically noted, enter the spaces between proximate blades of the opposing rotor assembly and at such times, each blade tip approaches quite close to the core of the opposing assembly, and with the cutting edge of the blade quite close to the advanced blade of the opposing rotor assembly. In the embodiment described above, the closest approach of a blade to the core of the opposing rotor assembly is but of the order of 1/16 of an inch, and the distance between the cutting edge of such blade to the advanced blade of the opposing rotor assembly, will be but of the order of 0.072 inches. Thus for cuttings exceeding such thickness, they will be exposed to crushing and shearing forces, which increase in magnitude with the thickness of the cutting or branch being fed to the apparatus.

Thus material fed to the apparatus, will not only pass through such apparatus with amazing speed, but in the course of such movement, will be simultaneously exposed to cutting, tearing, bending, compression and shearing forces, all of which, in acting upon the material, produce small chips and pieces, so mutilated as to expose substantial internal fiber structure thereof.

It should be apparent also, that the cutting and mutilating action of the rotor assemblies, does not necessarily require that the material fed to the machine be in dry state, since the apparatus will impart similar forces and stresses to fresh cuttings as well as dry ones. In fact, the apparatus does an excellent job on such materials as rotted fruit, orange and grapefruit rinds, and like materials.

In view of the speed with which the rotor assemblies self feed material through the apparatus, and, with a factor of safety in mind, the hopper is of substantial height and narrow in width, with flanges 61 along the longer edges of the entrance thereto.

To assure true parallelism between the shafts of the rotor assemblies, the bearings 7 are adjustably installed in oversize openings in the walls and partition of the housing, and to assure against spreading due to the compressive forces developed between the rotor assemblies during operation upon a branch or the like, set screws 63 mounted in the walls of the housing at appropriate locations, are threaded into pressure engagement with the bearings, and locked in such position by lock nuts.

To absorb shock loads and assure more uniform rotational movement of the rotor assemblies when exposed to shock loads, a flywheel 65 may be mounted on the exposed end of the drive shaft where coupled to the drive motor, and the coupling which drive connects the drive motor to the drive shaft may involve one of the flexible coupling type 67 mounted on the drive motor shaft and bolted to the flywheel, which in turn would be keyed to the drive shaft.

To facilitate servicing or replacement of the rotors, the approximate end wall 9 abuts against flanges extending inwardly from side walls of the housing 15, to which flanges, the end wall 9 may be removably secured as by bolting or equivalent means.

The embodiment of the invention described above, provides for vertical feeding of the cuttings to the cooperating rotor assemblies.

In some instances, it may be desirable to feed the cuttings to the apparatus in a more or less horizontal direction, and with this in mind, the housing 15 may be constructed for rotation through an angle, about the drive shaft 5 as an axis, the permissive angle of rotation being such as to expose the cooperating sides of the rotor assemblies to a more or less horizontal approach for the feeding of cuttings and the like.

From the foregoing description of my invention in its preferred form, it will be apparent that the same fulfills all the objects attributable thereto, and while I have disclosed the same in considerable detail, it will be apparent that the same is subject to alteration and modification without departing from the underlying principles involved, and I, accordingly, do not desire to be limited in my protection to the specific details illustrated and described, except as may be necessitated by the appended claims.

I claim:

1. A device for reducing plant cuttings to small particles suitable for composting comprising a pair of cooperating rotors each including a cylindrical core of metal having at least twelve peripheral slots evenly distributed thereabout and a blade anchored in each of said peripheral slots at a rake angle of about 20, means rotatably mounting said rotors with blades of one rotor interleaving blades of the other, means driving said rotors in opposite directions, said rotor drive means including a housing having a pair of side walls and front and rear walls, a partition in said housing transverse thereof and creating a rotor compartment and a gear compartment, said rotor compartment having an open top and bottom and said gear compartement having roof and floor elements suitable for containing oil, a main drive shaft and a supplemental drive shaft passing ized by screw pressure means adjustable against certain of said bearings to resist spreading between said drive shafts in response to loads placed on said rotors when in use. I

4. Cooperating rotors in accordance with claim 1, characterized by each of said blades being anchored in its slots by an adhesive.

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Claims (4)

1. A device for reducing plant cuttings to small particles suitable for composting comprising a pair of cooperating rotors each including a cylindrical core of metal having at least twelve peripheral slots evenly distributed thereabout and a blade anchored in each of said peripheral slots at a rake angle of about 20*, means rotatably mounting said rotors with blades of one rotor interleaving blades of the other, means driving said rotors in opposite directions, said rotor drive means including a housing having a pair of side walls and front and rear walls, a partition in said housing transverse thereof and creating a rotor compartment and a gear compartment, said rotor compartment having an open top and bottom and said gear compartement having roof and floor elements suitable for containing oil, a main drive shaft and a supplemental drive shaft passing through said transverse partition and connected to drive said rotors, a power unit coupled to drive said main drive shaft at about 3,600 rpm, and a flywheel coupled to said main drive shaft.

2. Apparatus in accordance with claim 1, characterized by means removably securing said end wall adjacent said rotor compartment whereby to facilitate removal and installation of said rotors.

3. Apparatus in accordance with claim 1, characterized by screw pressure means adjustable against certain of said bearings to resist spreading between said drive shafts in response to loads placed on said rotors when in use.

4. Cooperating rotors in accordance with claim 1, characterized by each of said blades being anchored in its slots by an adhesive.

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