the general structure of a device according to the invention is apparent from fig1 and 2 . the figures show a housing 1 , which is made up of a cylindrical lower piece 2 and a bell - shaped upper piece 3 . the longitudinal axis of the housing 1 is provided with the reference symbol 4 . the lower piece 2 is closed off downward by a base 5 , in which a circular opening 6 is disposed concentric to the shaft 4 . opening 6 serves to receive an essentially cylindrical shaft bearing 7 , which is screwed onto the base 5 coaxially to the shaft 4 with a flange connection . the upper end of the shaft bearing 7 extends into the area of the upper piece 3 . in this way , within the lower piece 2 , an annular channel 8 is formed , which opens over a material outlet 9 from the housing 1 that runs tangentially to the shaft 4 . the upper terminus of the bottom piece 2 forms a circumferential annular flange 10 , to which a support ring 11 of angular cross - section is fastened . as was previously mentioned , the external shape of the upper piece 3 resembles a bell , while the inner circumference of the upper piece 3 has a conical shape and serves to receive a stator . the upper side of the upper piece 3 is closed by a removable lid 12 , which has a centered opening in the area of the shaft 4 , followed coaxially with an inlet port 13 for filling the device with input material . the foot area of the upper piece 3 is designed with its outer circumference complementary to the inner circumference of the support ring 11 , so that the upper piece 3 can be inserted with its foot area axially into the lower piece 2 . for reliable fastening of the upper piece 3 on the lower piece 2 an annular flange 14 proceeding plane - parallel to the outer circumference and coaxially is provided , which is fastened to the lower piece 2 with screws 15 . within the shaft bearing 7 , the drive shaft 17 directed coaxially to the shaft 4 is held rotatably within the shaft bearing 7 . the lower end of the drive shaft 17 , lying outside the housing 1 , is connected to a rotary drive , not shown in further detail . the opposite end , lying in the inner region of the housing 1 , extends far into the region of the upper piece 3 and serves for irrotatably receiving a rotor 18 , the more specific design of which will be explained in further detail with additional reference to fig3 to 5 . the rotor 18 is made up of several sections and comprises a monolithic base piece 19 in the form of a truncated cone , which is seated irrotatably on the drive shaft . the outer circumference 20 of the base piece 19 is surrounded in a form - locking manner by a rotor jacket 21 , the more detailed design of which is apparent primarily from fig5 . essentially the rotor jacket 21 has a hollow truncated cone - shaped piece 22 , which is slid axially onto the base piece 19 and an annular flange 23 , extending in a radial plane to the shaft 4 , which is formed on the upper , smaller - diameter inner circumference of the hollow truncated cone - shaped piece 22 . in the assembled state of the rotor 18 , the underside of the annular flange 23 comes to lie in a complementary - shaped , annular indentation in the upper front face 24 of the rotor 18 . the annular flange 23 thus serves as a detent and supporting surface for the positionally accurate axial and radial seating of the rotor jacket 21 on the base piece 19 . as fig5 in particular shows , the rotor jacket 21 is penetrated by a plurality of holes 25 , which are grouped in radial planes 26 at axial intervals , wherein the holes 25 of each radial plane 26 are arranged at uniform circumferential distances . in the present exemplified embodiment , the holes 25 of adjacent radial planes lie in each case on common mantle lines ; one of these is shown as a representative and designated by 27 . also falling within the framework of the invention , however , are embodiments in which the holes 25 of two adjacent radial planes 26 are disposed with a circumferential displacement relative to one another , for example in half the circumferential distance of two holes 25 . the holes 25 serve for precisely fitting accommodation of the first pin - shaped comminuting tools 28 . each of the first comminution tools 28 have a one - piece cylindrical pin , for example made of steel or ceramic , with a diameter between for example 5 mm and 10 mm , which on one end has a disk - like head broadening 29 ( fig3 and 6 ). as is apparent from fig3 and 6 , such comminuting tools 28 are passed through the holes 25 from the interior of the rotor jacket 21 , wherein the broadened head 29 comes to rest in a complementary indentation on the inner circumference of the rotor jacket 21 , thus coming to end flush with the inner circumference of the rotor jacket 21 . there the base piece 19 presses with its outer circumference against the rotor jacket 21 and the heads 29 and in this way forms an abutment to fix the comminuting tools 28 in their operating position . a rotor 18 completely equipped with comminuting tools 28 is clearly shown in fig4 . there one also sees that the comminuting tools 28 project perpendicularly out of the circumferential surface of the rotor jacket 21 , which in the case of conical - shaped rotors 18 means that the comminuting tools 21 are not aligned in the radial direction , in other words , they are not perpendicular to the shaft , but form an angle with the radial planes 26 , corresponding to the conicity of the rotor 18 . the front face 24 of the rotor 18 is covered with an impact disk 30 arranged coaxially to the shaft 4 and its outer edge extends to the outer circumference of the rotor jacket 21 . here the impact disk 30 overlaps the annular flange 23 radially ; wherein the top side of said annular flange comes to lie in a complementary shaped indentation on the underside of the impact disk 30 . in this way , the annular flange 23 is embedded in a positive - locking manner between the base piece 19 and the impact disk 30 . thus the impact disk 30 clamps the annular flange 23 and thus the rotor jacket 21 against the base piece , which takes place by means of the screws indicated by 31 , which extend through the impact disk 30 and the annular flange into the base piece 19 . on the top side of the impact disk 30 , in the area of the outer circumference , six rectangular impact strips 32 are fastened , which are diametrically opposite one another in pairs with radial alignment . by maintaining an axial distance between the impact disk 30 and the cover 12 or the inlet port 13 , a disk - like chamber 22 is formed , in which pre - comminution of the input material takes place . in addition , fig1 , 2 and 6 show a stator coaxially surrounding the rotor 18 with a hollow truncated cone shaped stator jacket 33 , which extends in a positive - locking fashion along the inner circumference of the housing upper part 3 . the upper edge of the stator material 33 has an annular projection 37 for centering and interlocking with the upper part 3 . the lower edge is enclosed by a clamping ring 34 , which is screwed together with the upper piece 3 . in this process , the annular shoulder molded onto the inner circumference of the clamping ring 34 engages behind an annular attachment piece at the adjacent end of the stator jacket 33 . in this way the stator jacket 33 is fastened by clamping in the upper housing part 3 . the internal circumference of the stator jacket 33 proceeds at a uniform radial distance to the outer circumference of the rotor 18 , resulting in the formation of an annular gap that forms the comminution zone into which the first comminuting tools 28 extend . in analogy to the rotor jacket 21 , the stator jacket 33 is also penetrated by a plurality of boreholes , which serve to receive two pin - like comminuting tools 36 , which correspond in type to the first comminuting tools 28 . the holes and the second comminuting tools 36 are disposed respectively in axially spaced radial planes , wherein the relative position of the radial planes of the stator jacket 33 relative to the radial planes 26 of the rotor jacket 31 is such that an axial offset results in a combing arrangement of the first comminuting tools 28 and second comminuting tools 36 . the type of fastening of the second comminuting tools 36 in the stator jacket 33 also corresponds to that achieved with the rotor jacket 21 , so that the statements made regarding that apply appropriately . the comminuting tools 36 have a broadened head , which lies in a positive - fitting indentation and ends flush with the outer circumference of the stator jacket 33 . in this process the upper part 3 presses from behind against the circumferential surface of the upper piece 3 and the ends of the comminuting tools 36 and in this way retains these in the indentations . a device according to the invention operates as follows . through the input ports 13 , the input material axially enters the chamber 22 , where a first impact of the input material on the impact disk 30 takes place . there the input material is deflected in the radial direction and driven radially outward by centrifugal force , where it is captured and pre - comminuted in the outer circumferential area of the impact disk by the rotating impact strips 32 thereon . then the pre - comminuted input material is deflected in an axial direction , whereupon it enters into the annular gap 35 and is further broken up and comminuted there between the rotating first comminuting tools 28 and second , fixed comminuting tools 36 . the sufficiently processed input material leaves the annular gap 35 axially toward the bottom and enters the annular channel 8 , from where it passes out of the housing 1 via the material outlet 9 . for changing the tools , first the upper part 3 of the housing 1 is removed . then , after releasing the impact disk 30 , the rotor jacket 21 can be pulled off axially from the base piece 19 of the rotor 8 and replaced by a rotor jacket 21 equipped with new comminuting tools 28 . the replacement of the stator jacket 33 takes place in a similarly simple , rapid manner ; after releasing the clamping ring 34 , this can be removed axially from the top piece 3 . the replacement of the comminuting tools 28 on the rotor jacket 21 or the comminuting tools 36 on the stator jacket 33 is done by sliding the comminuting tools out of the corresponding holes and inserting new comminuting tools 28 , 36 until their broadened heads come to lie in the complementary - shaped indentations in the rotor jacket 21 or stator jacket 33 . the invention being thus described , it will be obvious that the same may be varied in many ways . such variations are not to be regarded as a departure from the spirit and scope of the invention , and all such modifications as would be obvious to one skilled in the art are to be included within the scope of the following claims .