An apparatus for comminuting commercial and industrial waste, particularly for comminuting paper, wood, plastics, etc., with a material loading chamber, as well as a material outlet region with a receiving container having an outlet opening for the material to be comminuted and with a comminuting mechanism, which is disposed in the receiving container and comprises a comminuting tool that can be caused to rotate by means of a drive motor. In order to create, particularly with a reduced construction and design effort, a comminuting apparatus, with which material can be comminuted effectively to a predetermined extent, the comminuting mechanism comprises at least two, essentially coaxially disposed comminuting tools one of which can be caused to rotate by means of the drive motor, the other of which, on the other hand, is disposed to be stationary or to rotate at a low rotational speed. Moreover, one of the comminuting tools has classification form recesses which are open towards the other comminuting tool. The other comminuting tool has at least two pocket recesses which can be connected with the classification form recesses, one pocket recess being assigned to the material loading chamber and the other pocket recess being assigned to the material outlet region.

The invention is directed to an apparatus for comminuting commercial and 
industrial waste, particularly for comminuting paper, wood, plastics, etc. 
BACKGROUND OF THE INVENTION 
Comminuting apparatuses of the above-described type are known in very 
different designs. If commercial or industrial waste, such as wood, is to 
be comminuted to a particular extent with such apparatuses, the 
consecutive disposal of several comminuting steps or comminuting steps or 
mechanisms, for example, is known. Moreover, for impeller breakers for 
example, it is known to combine a comminuting mechanism with a screening 
device in order to obtain comminuted material of the desired size or 
consistency. Such conventional comminuting apparatuses have the common 
disadvantage that, between the comminuting steps or between the 
comminuting mechanism and the classification apparatus, the comminuted 
material must pass through paths or overcome distances, which usually is 
to be brought about by gravitational or centrifugal forces. Particularly 
with lightweight, moist or greasy comminuted material, this is usually 
very difficult to carry out and only with the danger of blocking the 
apparatus and the like. Moreover, with multi-step comminuting apparatuses, 
the exact coordination of the individual comminuting steps creates 
problems. Because of the irregular comminution in a comminuting step, this 
usually leads to a larger dimensioning of the subsequent step. The design 
and construction costs associated therewith are appreciable, with the 
result that the production costs are considerable and that such 
apparatuses therefore are expensive. 
SUMMARY OF THE INVENTION 
It is an object of the present invention, to provide an apparatus of the 
initially mentioned type with reduced design and construction costs, with 
which commercial and industrial waste, particularly paper, wood, plastics, 
etc., can be comminuted effectively. 
In the inventive apparatus, the material to be comminuted is effectively 
comminuted or milled and classified to the desired degree with only one 
comminuting mechanism, which comprises the comminuting tool having the 
pocket recesses as well as the comminuting tool having the classification 
form recesses. The classification form recesses, in conjunction with the 
pocket-shaped recesses, see to it that the comminuted material is handed 
over to the material outlet region only when it has reached a desired 
degree of comminution without requiring any special classification units 
or further comminuting steps for this purpose. By means of a suitable 
construction of pockets and classification form recesses or by suitably 
matching pockets and classification grooves to one another, an optimum 
result can be obtained for each application with simple structural means. 
The production costs of this apparatus can be reduced considerably by 
these means in comparison to those of conventional comminuting 
apparatuses. 
The pockets or also the classification form recesses can be provided in the 
driven comminuting tool or also in the comminuting tool, which is 
stationary or rotating at a low circumferential speed. Depending on the 
nature of the material to be comminuted or on the size or consistency that 
the comminuted material is desired to have, it is possible to dispose one 
or more pockets in the direction of the material loading chamber as well 
as in the direction of the material outlet region. The classification form 
recesses preferably are groove-shaped and are kept open towards the 
material loading chamber, as well as towards the outlet region. The 
classification or comminuting result can easily be influenced by the 
width, depth, etc. of the grooves. Moreover, it is likewise possible to 
maintain the classification form recesses towards the material loading 
chamber or towards the outlet region of the receiving vessel open. 
Preferably, the comminuting tool, which has the pocket recesses, is a 
rotatably mounted, driven rotor knife with an essentially disk-shaped 
configuration, which rotates concentrically with a vertical axis of 
rotation within an essentially disk ring-shaped stationary knife. Both, 
the stationary knife and the rotor knife can be of relatively small 
construction. The driven rotor knife can be driven from below in such a 
manner, that it is mounted directly on the drive shaft of a reduction 
gear. Preferably, the stationary knife and the rotor knife separate the 
material loading chamber from the outlet region. 
For a more detailed explanation of the invention, reference is made to the 
dependent claims, the drawing and the further specification.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Different embodiments of the first comminuting tool and one embodiment of 
the second comminuting tool are illustrated in the drawing. The 
comminuting apparatus as a whole, for comminuting commercial and 
industrial waste, comprises a receiving container, which preferably, has a 
vertical main axis and goes over into a funnel in its lower region. 
Advisably, the comminuting mechanism is disposed in the region of the 
transition to the funnel shape, so that the outlet region with an outlet 
opening is below the comminuting mechanism, so that the material charging 
or loading chamber, which is located above the comminuting mechanism 
within the receiving container, is separated from the outlet region of the 
container by the cutting mechanism. Although the details are not shown, 
the cutting motor should have a drive motor with a drive shaft as well as 
a reduction gear. The drive shaft of the cutting mechanism or the drive 
shaft of the reduction gear has an essentially vertical axis of rotation, 
which advisably coincides with the main axis of the container. 
The cutting mechanism of the inventive comminuting apparatus has a first 
comminuting tool, which, in the embodiments shown, is formed by a 
rotatably mounted rotor knife 1, which can be shifted in the direction of 
rotation by means of the driving mechanism. This rotor knife 1 has an 
essentially disk-shaped configuration with a outer cylindrical surface 2 
and is disposed within the second comminuting tool (FIG. 5), which, in the 
embodiment illustrated, is constructed as a ring disk-shaped stationary 
knife 3 with an inner cylindrical surface 4. The rotor knife 1 shall be 
driven from below and therefore from the outlet region of the comminuting 
apparatus. Due to the overall narrow construction of the rotor knife 1 as 
well as of the stationary knife 3, the rotor knife 1 can be mounted 
directly on the drive shaft of a reduction gear, which is not shown. 
The stationary knife 3 and the rotor knife 1 separate the material loading 
chamber of the receiving container from the outlet region of the 
comminuting apparatus, so that the comminuted material can leave the 
comminuting apparatus only when all of it has passed through the rotor 
knife 1 and the stationary knife 3. In the embodiments shown, the rotor 
knife 1 is provided with the pocket-shaped recesses 5 and 6. In the 
embodiment shown in FIG. 1, a total of two pocket-shaped recesses 5, 6 is 
provided. The shaped recess 5 is disposed at the top and therefore 
assigned to the material loading chamber and the other pocket recess is 
disposed at the bottom and therefore assigned to the material outlet 
region. These pocket recesses 5, 6 essentially are semicircular in cross 
section and act together with the classification recesses 7, which are, 
for example, in the form of continuous grooves as shown in the stationary 
knife illustrated in FIG. 3. The pocket-shaped recesses 5, 6 and the 
classification form recesses 7 constitute opposite profiles, which, 
because of the size and shape selected, represent the classification 
dimension and therefore the comminuting size or quality of the comminuted 
material. In a structurally simple manner, the material to be comminuted 
can be comminuted by a simple configuration of pockets and classification 
grooves to a dimension, which corresponds to a granulate or a milled 
material. Moreover, the number of pocket recesses 5 and 6 advisably is 
selected on the basis of the size of the material, which is to be charged 
and comminuted, and of the circumferential dimensions of the knife that 
has been selected. If the material to be comminuted is particularly coarse 
or larger, it is advisable to provide an upper and a lower pocket-shaped 
recess, which extend over half the circumferential region of knife 1, as 
shown in the embodiment of FIG. 1. In the end regions of the upper 
pocket-shaped recesses 5, cutting edges 5.1 are constructed, which are 
aligned vertically on the whole. Cutting edges 7.1 are also constructed in 
the end regions of the classification recesses 7. 
In the embodiment of the rotor knife 1 shown in FIG. 2, the pocket-shaped 
recesses 5 and 6 of the rotor knife 1 are formed owing to the fact that 
the slanted disk forms the rotor knife 1, on the upper side of which 
dentiform pieces 8 with cutting edges 8.1 are provided. If the material to 
be comminuted is smaller, it is advisable to provide several pocket-shaped 
recesses 5 and 6, as shown in FIGS. 4 and 5. For this embodiment, a total 
of three pocket recesses 5, each with cutting edges 5.1 are disposed on 
the upper side, that is, aligned in the direction of the material loading 
chamber and three lower pocket-shaped recesses 6 are provided, which are 
offset to the upper pocket recesses 5 in the circumferential direction. 
Due to the double arrangement of cutting edges 5.1 at each pocket recess 5, 
cutting edges are provided for clockwise as well as for counter-clockwise 
rotation. 
The pocket-shaped recesses 5 and 6, particularly however the pocket-shaped 
recesses 6, are inclined from the bottom surface up to the classification 
form recesses 6 or constructed in arched form, so that, in conjunction 
with the classification form recesses 7, they act so as to convey the 
material downwards. If the material to be comminuted is very large, a 
primary crusher, which is formed, for example, by a toothed, inclined 
plate, as illustrated in greater detail in the European publication 0 285 
011, is disposed ahead of the rotor knife 1. 
When the inventive comminuting apparatus is operating the material to be 
comminuted passes from the loading chamber of the receiving container into 
the pocket-shaped recesses 5 of the rotor knife 1, which is facing or 
assigned to the material loading chamber. During the rotary motion of the 
rotor knife 1, the material to be comminuted is severed, cut or ground up, 
depending on the length and depth of the classification form recesses 7, 
by the cutting edges 5.1 or the opposite cutting edges of the 
classification form recesses 7. The severed material, which is to be 
comminuted, is then passed on to the pocket recess 6, which is assigned to 
the outlet region, when this pocket recess 6 stands in front of the 
classification form recess holding the severed material 7, which is to be 
comminuted. Depending on the shape of the pocket-shaped recess contour, 
the severed, comminuted material is then conveyed to the material outlet 
region. This is possibly particularly because the severed, comminuted 
portion of the material expands after the comminuting process in the lower 
pocket 6 and can be caught hold of. The pocket recesses 5 and 6 and the 
classification form recesses 7 can be provided either in the driven 
comminuting tool or also in a stationary comminuting tool or also in a 
comminuting tool rotating with a low circumferential speed. At low 
revolutions per minute, or also when the diameter of the knife is smaller, 
it is advantageous to provide the pocket recesses in the rotor knife 1, as 
shown in the embodiments. At higher revolutions per minute and with a 
larger knife diameter, the providing of pocket-shaped recesses 5 and 6 in 
the stationary knife offers advantages, since the centrifugal force also 
can be used additionally for the ejection in order to take off the 
severed, comminuted material. In this case, the corresponding 
classification form recesses should be provided in the rotor knife in an 
analogous manner. 
In FIG. 6, an embodiment of a cutting tool is shown, which is provided with 
classification recesses and has two stationary knives 3, 3.1, which are 
disposed one above the other. The upper stationary knife 3.1 with the 
sealed design of the groove-shaped classification recesses 7.2 serves as a 
coarse stationary knife for the preliminary cut. The stationary knife 3.1 
underneath, with its classification form recesses 7, serves for a refining 
cut of the material charged and has, for example, a construction as shown 
in FIG. 3. Due to the arrangement of two or more stationary knives with 
cuts becoming finer from the top to the bottom, increased throughput rates 
can be achieved. The rotating comminuting knife, used in this connection, 
need have pocket-shaped recesses, which are open towards the bottom, only 
in the region of the stationary knife with the smallest classification 
form recesses. 
In FIG. 7, a comminuting tool is shown in a spiral screw segment-shaped 
design. This can be rotated in one direction of rotation. The spiral screw 
can be a single-flighted screw or a multi-flighted screw. The cutting 
edges 5.1 work together with the stationary knife having the 
classification form recesses. The cutting edge 5.2 of the end face works 
on impact without a counter cutting edge. The spiral screw periphery and, 
with that, the cylindrical surface of the rotor knife separate the upper 
cutting space from the lower cutting space.