US3743192A

US3743192A - Comminutor-mixer

Info

Publication number: US3743192A
Application number: US00159868A
Authority: US
Inventors: F Otto
Original assignee: Stephan A and Soehne GmbH and Co
Current assignee: Stephan A and Soehne GmbH and Co
Priority date: 1970-07-08
Filing date: 1971-07-06
Publication date: 1973-07-03
Anticipated expiration: 1990-07-03
Also published as: CA975264A; FR2098055A5; BE769470A; CH526341A; NL172411B; DE2033788B2; DE2033788A1; SU511836A3; NO130452B; NO130452C; NL7109324A; JPS5310147B1; GB1349406A; SE369847B; ATA446871A; NL172411C; AT329398B

Abstract

A comminutor-mixer has a first and a second stage. The first stage includes a drum having a peripheral wall and a horizontal axis with a rotatable shaft extending through the drum in parallelism with the axis thereof and carrying coarse-comminuting and mixing tools. A drive rotates the shaft and an outlet is provided in the peripheral wall at a downwardly directed portion. Located beneath the drum is a second comminuting stage including a receptacle having an upwardly directed inlet and being mounted for horizontal movement to and from a position in which the inlet registers with the outlet to receive material from the drum. A separate drive is provided for driving fine-comminuting and mixing tools located in the receptacle.

Description

United States Patent 1 1 1 1 3,743,192 Otto July 3, 1973 COMMlNUTOR-MIXER 3,313,332 4/1967 Stephan et a1. 146/79 X 3,580,315 5/1971 Schnell 146/79 [751 Friedrich Wes", 3,486,649 12/1969 Schaller 146/182 ux Germany Assignee; A, Stephan Und Sohne, Primary Examiner-Willie Abercrombie Hameln/Wesen Germany Attorney-Michae1 Striker [22] Flled: July 6, 1971 ABSTRACT [211 App! 159368 A comminutor-mixer has a first and a second stage. The first stage includes a drum having a peripheral wall [30] Foreign A li ti P i it D t and a horizontal axis with a rotatable shaft extending July 8 1970 Germany P 20 33 788.6 hmugh drum in paanelism with axis and carrying coarse-comminuting and mixing tools. A 521 U.S. c1. 241/101 1;, 241/152 A drive mates Shaft and Pmvided 51 1111. C1. B026 18/14 Peripheral a dwnwardly directed 58] Field of Search 146/78 R, 79, 182 R, cated beneath the drum is a Sewn! mminufing Stage 146/183, 186 including a receptacle having an upwardly directed inlet and being mounted for horizontal movement to 56] References Cited and from a position in which the inlet registers with the outlet to receive material from the drum. A separate UNITED STATES PATENTS drive is provided for driving fine-comminuting and mix- 2,863,480 12/1958 Combs 146/182 R ing tools located in the receptacle 2,941,561 6/1960 Pana 1 146/182 R 3,461,934 8/1969 Waters 146/182 R X Claims, 2 Drawing Figures 3 Z 9 4 A /j 2 \T l\ I II 1 I V L i T::'T I j i I [4 1 n i i I I] 1 1 l 22 1 1 1 1 1 1 I l l I I 7( 1 M 1.. M 1 u L-l Patented July 3, 1973 2 Sheets-Sheet l lnrentar: pmeomcq 01'1' 4,: lama Patented July 3, 1973 .2 Sheets-Sheet 2 Amara COMMINUTOR-MIXER BACKGROUND OF THE INVENTION The present invention relates generally to a comminutor-mixer apparatus, and more particularly to a novel comminutor-mixer for foodstuffs and the like.

From many applications it is known to provide comminutor-mixer apparatus with two stages, a first or coarse-comminuting or mixing stage, and a second or fine-comminuting or mixing stage. It is conventional to provide these stages in form of separate devices, and the material which has undergone preliminary or coarse comminution and mixing is transported under vacuum to the second or fine-comminuting and mixing stage. However, in some instances the material is not transported under vacuum or comes in contact with the atmosphere before or after it has been transported under vacuum, and there are circumstances in which such contact with the atmosphere is undesirable.

It is also known to provide this type of apparatus with the two stages in a unitary construction. Here, however, the disadvantage has been experienced that the impossibility of separating the fine-comminuting device from the coarse-comminuting device, makes it also impossible to combine fine-comminuted masses with coarse-comminuted components which are not to be further fine-comminuted. In other words, it is not possible to subject only some of the material to both coarse and fine communition and to subject a part of the material merely to coarse communition. Also, there are materials which can be treated in the coarse comminutor alone, but which cannot be treated or should not be treated with fine comminutor, for instance nuts.

Devices of this general type are, for instance, described in German Pat. No. 1,201,207. They use a coarse comminutor having a bowl in which a centrallyarranged vertical axis or shaft rotates, and in which comminuting and mixing tools rotate about this axis. In the bottom of the bowl, there is a closeable aperture plate through which the coarse-comminuted material passes into the subsequently arranged finecomminuting device which constitutes an inseparable unit with the coarse-comminuting device. The tools in both the coarse and fine-comminuting devices are driven by one and the same motor in unison. The apparatus has only one outlet for the comminuted and mixed material, namely the outlet in the finecomminuting device through which the material is expelled by the tools in the fine-comminuting device.

Actually, this type of apparatus has been found highly valuable in regular use. It is, however, possessed of certain features which make it desirable to provide improvements. In particular, th unitary construction of coarse and fine-comminuting devices means that the material admitted into the coarse-comminuting device must, under all circumstances, also pass through the fine-comminuting device, with the disadvantages that have been outlined above. It is thus impossible to maintain some of the material (for instance some additives or the like, such as spices) in coarsely-comminuted state, while having the remainder finely comminuted. Also, it is not possible to completely remove the tools in the fine comminutor if, for instance, only coarse comminution should be desired, because these tools are necessary to make the material pass through the outlet provided in the fine comminutor.

When in this prior-art apparatus the aperture plate is opened, that is when the apertures thereof are uncovered, the material issupplied by the cutter knives or tools into the fine comminutor in which it undergoes fine comminution. However, because the comminuting and mixing tools of the coarse comminutor continue to operate because they are driven jointly with the tools of the fine comminutor, the material will have a differential consistency and undergo differential heating when the unit operates in batchwise manner.

The fine comminutor is provided wtih tools which rotate at relatively high speeds, and this means that certain materials or components cannot be processed or advanced in the fine comminutor towards the outlet. As mentioned before, this includes nuts where the danger exists that the relatively strong heating resulting from the action of the high-speed tools might cause oil to become expelled from the nut meat.

Also, finished flour cannot be expelled by the fine comminutor, it having been found experimentally that if flour passes through the fine comminutor (a material which is not truly flowable), it can cause the motor to become stalled.

Another disadvantage is the fact that it is quite difficult to exchange the tools in the fine comminutor. It is certainly possible to effect such an exchange only after the fine comminutor is first emptied out, which of course is a decided disadvantage.

SUMMARY OF THE INVENTION It is, accordingly, an object of the present invention to avoid thedisadvantages of the prior art and to solve those problems which exist in the prior art.

More particularly, it is an object of the present invention to provide an improved comminutor-mixer of the general type in question which is not possessed of these disadvantages.

Still more particularly, it is an object of the invention to provide such a comminutor-mixer in which materials such as foodstuffs can undergo coarse comminution, emulsification, mixing, fine comminution, or finest comminution and which apparatus can operate if desired either under vacuum or under overpressure.

An additional object is to provide such an apparatus which is as small as possible, especially with respect to its height, which can be produced readily and comparatively inexpensively, and which can be readily accommodated to different requirements in combination with different foodstuffs to be processed.

In pursuance of the above objects, and of others which will become apparent hereafter, one feature of the invention resides in a comminutor-mixer, particularly for foodstuffs, which briefly stated comprises first means constituting a coarse comminuting and mixing stage and second means constituting a fine comminuting and mixing stage. The first means includes a drum having a peripheral wall and a substantially horizontal axis, a rotatable shaft in the drum in at least substantial parallelism with the aforementioned axis and carrying a plurality of coarse-comminuting and mixing tools, a drive for rotating the shaft, and an outlet at a downwardly directed portion of the peripheral wall. The second means includes a receptacle having an upwardly directed inlet, a mounting arrangement mounting the receptacle beneath the drum for horizontal displacement relative to the same to and from a position in which the inlet registers with the outlet, and a separate 3 drive for-driving fine-comminuting and mixing tools in the second means.

A comminutor-mixer constructed in this manner according to the present invention, is of particularly wideranging versatility. For instance, if it is desired that the material be subjected to coarse comminution, then it is simply necessary to move away the second stage and instead to provide a receptacle which receives the coarsely-comminuted material from the outlet of the first stage. Again, if the degree of fine comminution is to be changed, then it is merely necessary to move the fine comminutor temporarily away from the coarse comminutor stage, to gain access to the tools of the fine comminutor which can then be exchanged for a different set providing the desired comminuting characteristics.

Of course, it is clear that because the material to be processed now is no longer forced to pass through the fine-comminuting stage, the coarse comminutor can be employed simply as a mixer if desired.

By locating the shaft for the comminuting and mixing tools in the drum of the first stage eccentrically with reference to the axis of the drum, relatively short tool lengths and a correspondingly smaller motor capacity are required, by comparison with the normally utilized vertical or near-vertical shaft. Thus, the smallest possible free space, which is not contacted by the tools, intermediate the free ends of the tools and the inner wall of the drum or the transporting vane located. between them, can be achieved even if the drum has a relatively large diameter, using only relatively short tools.

A further advantage resides in the fact that the upper portion of the drum beneath the inlet now is provided with a relatively large space free of the tools, so that even large items of material to be comminuted can be introduced without any necessity for the coarse comminutor to be already in operation at the time of introduction.

Furthermore, it is now no longer necessary to provide the outlet laterally because the motor varying can be provided, and in fact is provided, at one endwall of the drum. This means that the drum can be emptied much more readily, particularly by the aid of the transport vane which is also provided and which is more effective in this construction than those known from the prior art.

For practical applications, the novel construction according tothe present invention has the particular advantage that the second stage can be represented by already-existing commercially available fine comminutors without having to make special adaptations to make it possible for them to cooperate with the novel first stage. This is especially advantageous in the many instances where a fine comminutor is already available, that is in industrial use, and restaurant use or the like, which is to be complemented by the first-stage coarse comminutor.

According to a particularly advantageous embodiment of the invention, the transport vane which is provided in the drum will rotate during comminuting and mixing in direction oppositely the direction of rotation of the comminuting and mixing tools, but will rotate in the same direction as these tools when it is desired to expel material from the drum. During the direction oppositely the rotation of the tools, the transport vane will scrape the material from the inner wall of the drum, and supply it upwardly from where it falls down again into the operative region of the tools. The tip of the angle included between the transport vane and the inner wall of the drum, extends in the direction of rotation of the vane. However, when it is desired to expel the material from the drum by opening the outlet of the latter, the direction of rotation of the vane is reversed so that it now rotates in the same direction as the tools in which case the angle included between the vane and the inner surface of the drum wall will point with its tip oppositely the direction of rotation of the vane, so that the material contacted by the transport vane, will be pressed against the drum wall and thus pressed into the outlet provided in the latter.

It is possible in some circumstances for the toolsof the coarse comminutor not to rotate at all, or only with a lower rotational speed than otherwise, when the material is to be expelled from the drum, and this is possible because the transport vane is driven separately. The transport vane, incidentally, is advantageously journalled centrally in one of the endwalls of the drum, and of angular configuration, with one arm being provided with a scraping edge contacting the inner side of the one endwall and the other arm having an appropriately configurated scraping edge which contacts the inner side of the circumferential wall of the drum. The endportion of this other arm may also be provided with a scraping edge which contacts the inner side of the opposite end-wall of the drum. With such a construction, the entire inner surface of one of the walls and of the circumferential wall will be scraped, and an annular portion of the inner surface of the opposite endwall as well, thereby making possible a complete explusion of the material from the drum. This means that the effectiveness of the transport vane is exceptionally high.

It is advantageous that the endwall in which the transport vane is journalled for rotation, be movable, or pivotable with reference to the drum. Because of this, a suitable'endswitch or the like must be provided which assures that the endwall can be removed only when the transport vane is in a predetermined position in order to avoid damage to the tools and/or the transport vane.

The mixing action in the drum can be further intensified by so configurating the cutting and mixing toolswhich are preferably equally distributed over the circumference of their shaft and of substantially identical length in direction normal to the shaft-that they impose upon the material being comminuted and mixed a component of movement in the drum in axial direction of the latter. This assures, inter alia, that certain components or quantities of the material being processed cannot become concentrated or deposited at a particular location within the drum. The direction of movement may be selected so that it moves away from the end-wall towards the transport vane. This avoids back-up of material at the endwall of the drum. The arrangement can, however, also be such that the tools are so configurated as to assure that one half of the material will move towards the transport vane, and the other half will move away from the transport vane in opposite axial direction.

The drum itself may be provided with a double circumferential wall, constituting a jacket for which heating and/or cooling medium can be circulated, and in such a case, the drum can for instace be used for the production of such materials as processed cheese.

If the entire apparatus including the second stage is to operate under vacuum, then the outlet of the first stage and the inlet of the second stage may be provided with a sealing arrangement which seals against interior underpressure, that is which provides a seal between the outlet and the inlet when the interiors of the two stages are under vacuum. At the same time, it is possible to provide in the outlet of the second stage, a suitable valve to prevent venting of the interior. It is also possible to provide means, well known per se in the art, to admit into either or both stages, steam and/or liquids.

Advantageously, the inner wall portions surrounding the inlet and/or the outlet of the drum are configurated to conform to the interior contour of the circumferential wall of the drum. Because the supply devices for the drum are usually of identical configuration and size, the upper inlet opening for the drum must be relatively large and communicates with the interior of the drum via a converging hopper or funnel. If now the upper inlet opening were to be closed merely by a simple cover, then material which is flung up by the rotating tools, could become deposited in the funnel-shaped hopper and such quantities which might shortly before completion of the coarse-comminuting process fall back into the interior of the drum, would then not be properly comminuted and provide for an improper consistency of the contents. The same is true of course for the outlet of the drum where it is also possible for quantities of the material to become deposited which then would be located outside the area of contact of the tools and transport vane and would be expelled together with the properly comminuted material. This would be particularly disadvantageous wherein the production of processed cheese, but also of other materials.

The inlet pivot drum can for instance be constructed as a pivotable cover which may be controlled for movement via compressed air or the like, and the outlet may be provided with a slide cover which can also be controlled by air pressure or the like.

Lifts may be located at the two lateral sides of the comminutor-mixer for lifting the material to the inlet of the first stage. For instance, if the drum can accommodate a quantity of 400 kg of material, the lifts may be provided with two lifting containers each of which can hold 200 kg of material.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. I is a partly longitudinally sectioned side view of an embodiment of the invention, with the inlet cover closed; and

FIG. 2 is an end view of FIG. 1, partly in section and showing the inlet cover open.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Discussing now the drawing in detail, it will be seen that the novel apparatus comprises two stages, a first or coarse-comminuted and mixing stage 1 and a second or fine-comminuted and mixing stage 2. The first state 1 comprises a drum 3 having a pivotable endwall 4 and an air pressure-actuated pivotable cover 5 which is provided for closing an inlet to the drum in form of a funnel-shaped hopper 6. Mixing and comminuting tools 7 are of identical length and equally distributed over the circumference of a shaft 8 which extends through the drum in parallelism with the horizontal axis 9 of the latter. The shaft 8 is rotated and the tools 7, of course, rotate with it.

At a lower portion of the circumferential wall 10 of the drum, there is provided an outlet 11 which can be closed and opened by an air pressure-actuated slide cover 12, and which can discharge coarselycomminut ed and mixed material into an inlet hopper 13 of the second comminuting stage 2 which is located beneath the stage 1 and can be horizontally displaced with reference to the latter, to and from a position in which the inlet hopper 13 registers with the outlet 11. In this embodiment, an underpressure-tight sealing device 14 is provided connecting the outlet 11 and the inlet hopper 13, so that the device can be operated under vacuum or under underpressure.

An angularly-shaped transporting vane 15 is journalled centrally in the endwall 4 and has an arm 16, a scraping edge 16a of which contacts the inner side of the endwall 4. The other arm 17 is provided with a requisitely configurated scraping edge 18 which contacts the inner side of the circumferential wall 10 of the drum. The free end of the arm 17 is also provided with a scraping edge 19 which contacts the inner side 20 at the opposite endwall of the drum 3. The inner wall portion 21 of the cover 5, as well as that of the cover 12, are configurated so as to conform to theinner contour of the circumferential wall 10.

The tools (not shown) of the second stage 2 are driven via a separate drive motor 22 which may usually be electrical, and the stage 2 is provided with an outlet 23 which may be provided with a suitable one-way outlet valve (not shown). At opposite lateral sides of the device having the stages 1 and 2, lifts 24 may be provided which are shown in broken lines in FIG. 2 for orientation.

Separate motors

25 and 26, again preferably being of electrical type, are provided for driving the shaft 8 and the transport vane 15, respectively, in rotation.

In operation of the novel device, the material to be subjected to comminution and/or mixing, is supplied via the lifts 24 into the drum 3, after first opening the cover 5. After the cover 5 is closed, the shaft 8 and the vane 15 are driven in rotation by their respective motors, and at such time, the vane 15 will rotate in a sense opposite to the direction of rotation of the shaft 8 and the tools carried thereby. During this period, the scraping edges of the vane will scrape the material from the inner walls of the drum 3 and move it upwardly so that it falls back into the region of the tools for engagement thereby. When the comminution is completed, or the mixing if only mixing is intended, the closure 12 is opened and at the same time, the direction of rotation of the vane is reversed so that it now rotates in the same sense as the tools. In so doing, it presses the contents of the drum against the inner surface of the drum wall and thus presses them into and through the outlet 11. It is, however, also possible to completely stop the rotation of the tools during this expulsion process, or to have them rotate at a lower speed then previously. This is evidently possible because separate drives are provided for the tools and vane, and it need not be discussed in detail (and being known per se) how the direction of rotation can be reversed, or how transmission of motion from the drives to the tools and vane, is effected.

When the coarse-comminuted and/or mixed material leaves the outlet 11, it enters the stage 2 via the inlet 13 thereof, where it undergoes fine comminution and- /or mixing in known manner, to leave there the outlet 23.

if only coarse comminution and/or mixing is desired, then the stage 2 is simply moved horizontally away from the drum 3 and a suitable receptacle, for instance a wheeled carriage or the like is placed beneath the outlet 11 to receive material therefrom. On the other hand, if the degree of fine comminution and/or mixing is to be changed, the stage 2 is simply moved away from the drum 3, the set of tools in the stage 2 is exchanged for a different set having the required characteristics, and the stage 2 is then returned to a position in which its inlet 13 registers with the outlet 11.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions differeing from the types described above.

While the invention has been illustrated and described as embodied in a comminuter-mixer, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention, and, therefore, such adaptations should and are intended to be comprended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims:

1. A comminutor-mixer, particularly for foodstuffs, comprising first means constituting a coarse comminuting and mixing stage and including a drum having a pe ripheral wall and a substantially horizontal axis, a rotatable shaft in said drum offset from but in at least substantial parallelism with said axis and carrying a plurality of coarse-comminuting and mixing tools, a drive for rotating said shaft, and an outlet at a downwardly directed portion of said peripheral wall; and second means constituting a fine comminuting and mixing stage and including a receptacle having an upwardly directed inlet, a mounting arrangement mounting said receptacle beneath said drum for horizontal displacement relative to the same to and from a position in which said inlet registers with said outlet, and a separate drive for driving fine-comminuting and mixing tools.

2. A comminutor-mixer, particularly for foodstuffs, comprising first means constituting a coarse comminuting and mixing state and including a drum having a peripheral wall and a substantially horizontal axis, a rotatable shaft in said drum in at least substantial parallelism with said axis and carrying a plurality of coarsecomminuting and mixing tools, a drive for rotating said shaft with said toois in one direction, and an outlet at a downwardly directed portion of said peripheral wall; at least one vane in said drum adapted for rotation opposite to said one direction during comminuting and mixing of material in said drum, and for rotation in said one direction when such material is to advance axially of said drum; and second means constituting a fine comminuting and mixing stage and including a receptacle having an upwardly directed inlet, a mounting arrangement mounting said receptacle beneath said drum for horizontal displacement relative to the same to and from a position in which said inlet registers with said outlet, and a separate drive for driving fine comminuting and mixing tools.

3. A comminutor-mixer, particularly for footstuffs, comprising first means constituting a coarse comminuting and mixing stage and including a drum having two endwalls, a peripheral wall and a substantially horizontal axis, a rotatable shaft in said drum in at least substantial parallelism with said axis and carrying a plurality of coarse-comminuting and mixing tools, a drive for rotating said shaft, and an outlet at a downwardly directed portion of said peripheral wall; at least one vane mounted rotatably in said drum and being centrally journalled in one of said endwalls, said vane being driven independently of said tools and having an angular configuration including one arm provided with a scraping edge which engages an inner side of said one endwall and another arm provided with a scraping edge which engages an inner side of said peripheral wall; and second means constituting a fine comminuting and mixing stage and including a receptacle having an upwardly directed inlet, a mounting arrangement mounting said receptacle beneath said drum for horizontal displacement relative to the same to and from a position in which said inlet registers with said outlet, and a separate drive for driving fine-comminuting and mixing tools.

4. A comminuting-mixer as defined in claim 3, said other arm having a free endportion and a part of said other scraping edge on said free endportion engaging an inner side of the other of said endwalls.

5. A comminuting-mixer as defined in claim 1, said coarse comminuting and mixing tools all being evenly distributed about said shaft projecting from the same by at least substantially identical distances, and being constructed and arranged for imparting to material in said drum a component of movement in direction longitudinally of said axis.

6. A comminuting-mixer as defined in claim 1; further comprising a heat-exchange jacket at said peripheral wall for circulation of a heat-exchange fluid through such jacket.

7. A comminuting-mixer as defined in claim 1; further comprising a sealing element between said outlet and inlet for affording a connection between the same which is sealed against at least underpressure.

8. A comminutor-mixer, particularly for foodstuffs, comprising first means constituting a coarse comminuting and mixing stage and including a drum having a pcripheral wall and a substantially horizontal axis, a rotatable shaft in said drum in at least substantial parallelism with said axis and carrying a plurality of coarsecomminuting and mixing tools, a drive for rotating said shaft, an inlet in said peripheral wall, and an outlet at a downwardly directed portion of said peripheral wall; said inlet and said outlet both being bounded by respective interior wall portions at least one of which is concomminuting and mixing tools.

9. A comminuting-mixer as defined in claim 1; further comprising hoist means at opposite sides of said first and second means, adapted to hoist material to be processed to said drum for introduction into the same.

10. A comminuting-mixer as defined in claim 1,

wherein said drives comprise electric motors.

Claims

1. A Comminutor-mixer, particularly for foodstuffs, comprising first means constituting a coarse comminuting and mixing stage and including a drum having a peripheral wall and a substantially horizontal axis, a rotatable shaft in said drum offset from but in at least substantial parallelism with said axis and carrying a plurality of coarse-comminuting and mixing tools, a drive for rotating said shaft, and an outlet at a downwardly directed portion of said peripheral wall; and second means constituting a fine comminuting and mixing stage and including a receptacle having an upwardly directed inlet, a mounting arrangement mounting said receptacle beneath said drum for horizontal displacement relative to the same to and from a position in which said inlet registers with said outlet, and a separate drive for driving fine-comminuting and mixing tools.

2. A comminutor-mixer, particularly for foodstuffs, comprising first means constituting a coarse comminuting and mixing state and including a drum having a peripheral wall and a substantially horizontal axis, a rotatable shaft in said drum in at least substantial parallelism with said axis and carrying a plurality of coarse-comminuting and mixing tools, a drive for rotating said shaft with said tools in one direction, and an outlet at a downwardly directed portion of said peripheral wall; at least one vane in said drum adapted for rotation opposite to said one direction during comminuting and mixing of material in said drum, and for rotation in said one direction when such material is to advance axially of said drum; and second means constituting a fine comminuting and mixing stage and including a receptacle having an upwardly directed inlet, a mounting arrangement mounting said receptacle beneath said drum for horizontal displacement relative to the same to and from a position in which said inlet registers with said outlet, and a separate drive for driving fine comminuting and mixing tools.

8. A comminutor-mixer, particularly for foodstuffs, comprising first means constituting a coarse comminuting and mixing stage and including a drum having a peripheral wall and a substantially horizontal axis, a rotatable shaft in said drum in at least substantial parallelism with said axis and carrying a plurality of coarse-comminuting and mixing tools, a drive for rotating said shaft, an inlet in said peripheral wall, and an outlet at a downwardly directed portion of said peripheral wall; said inlet and said outlet both being bounded by respective interior wall portions at least one of which is configurated in conformance with the internal contour of said peripheral wall; and second means constituting a fine comminuting and mixing stage and including a receptacle having an upwardly directed inlet, a mounting arrangement mounting said receptacle beneath said drum for horizontal displacement relative to the same to and from a position in which said inlet registers with said outlet, and a separate drive for driving fine-comminuting and mixing tools.

10. A comminuting-mixer as defined in claim 1, wherein said drives comprise electric motors.