Laboratory mill

Abstract

The invention relates to a laboratory mill (1), in particular in the form of a cutting mill or an impact cross mill, for comminuting ground material, comprising a device housing (12) having a grinder housing (16), the grinder housing (16) defining a grinding chamber (32) and having an axial end face (16a), a rotor grinder (30), which is located in the grinding chamber (32) of the grinder housing (16), the invention relates to a rotor grinding machine (30) comprising a rotor (34) and at least one mating element (36), the rotor (34) defining a rotor axis (X), between which material to be ground is comminuted when the rotor (34) is rotated, a grinding machine drive (2, 4) for driving the rotor (34) within a grinding chamber (32), a grinding machine housing door (18) for closing the grinding machine housing (16) on an axial end face (16a), the at least one mating element (36) being axially insertable into the grinding machine housing (36) when the grinding machine housing door (18) is opened.

Description

Technical Field

[0001] The invention relates to a laboratory mill, in particular a laboratory-scale cutting mill or cross-impact mill, which has a grinding machine in which the material to be ground is comminuted, for example by cutting and / or impacting action, in a grinding gap between a grinding rotor and one or more stationary mating elements. Background Art

[0002] Cutting mills comminute the material to be ground between a rotating cutting rotor and one or more substantially axially extending stationary cooperating cutting edges according to the shearing principle in a grinding gap extending axially therebetween, the cutting rotor having one or more rotor cutting edges also extending substantially axially. Such laboratory cutting mills are particularly suitable for comminuting viscous or fibrous samples, for example biological samples such as straw or for example plastic films, to name just a few. Examples of current laboratory cutting mills include, for example, the applicant's 19 and 15, whose basic structure is referred to here. 19 and A corresponding product description of 15 can be found, for example, at www.fritsch.de.

[0003] In these laboratory-scale cutting mills, a more or less flowable bulk material is usually introduced, for example, via a charging hopper, into a grinding chamber in which a cutting rotor rotates about a horizontal axis. The cutting rotor can have different geometries, for example with straight cutting edges or so-called V-shaped cutting edges. The latter have a swirl and thus achieve a good cutting action, especially when comminuting viscoelastic materials and films.

[0004] Usually, a screen, for example a screen box, is located below the cutting rotor, through which the sample material, which has been comminuted sufficiently intensively, can flow in order to be collected in a collecting container located below it.

[0005] With regard to further construction details of the cutting mill which are known in principle to the person skilled in the art, reference is made to the applicant's cutting mill. 19 and The product description of 15, which at the time of the application and its publication was available for download at www.fritsch.de, and the basic structure of this cutting mill is incorporated by reference therein. In addition, the application documents DE 196 01 594, DE 10 2018 113751 A1, WO 2020 / 200759 A1 and DE 10 2019 133 437 A1 describe such a cutting mill and are likewise incorporated herein by reference.

[0006] The cutting blades are subject to wear, so that the cutting gap can change undesirably over time. In addition, the cutting blades can be damaged by hard grinding material, which may require resharpening, whereby the width of the cutting gap also changes. Therefore, the grinding gap in such grinding machines is usually adjustable for the user, and the user can fine-adjust the cutting edge in order to set the width of the cutting gap between the cutting edge of the rotor and the mating cutting edge to the desired size and the desired parallelism. Fig.23 In conventional cutting mills 100, the radial positioning of the stationary counter-tool 102 is usually adjusted by means of two threaded pins 104. The counter-tool 102 is then pulled against the stop by means of a further screw 106 in order to fix it. The cutting edge of the rotor is usually fixed by shaping and grinding, or if a separate cutting edge is used on the rotor, it is mounted on the rotor and the cutting edge of the stationary counter-tool 102 is subsequently adjusted and fixed relative to the rotor cutting edge. Although this adjustment of the cutting gap has proven itself in principle, it also has some disadvantages.

[0007] Firstly, this adjustment is not particularly simple and requires experience, which can result in the user not always being able to perform this adjustment optimally. Furthermore, the grinding gap not only changes due to wear, but can also be adjusted after disassembly and reassembly. Especially in non-divided grinding machine housings, the cutting gap at the rear end on the motor side is difficult to access and measure.

[0008] A further disadvantage is that the user can also adjust the cutting gap or grinding gap too small. This then either results in a grinding gap that is too small, which can lead to increased cutting edge wear, overheating and higher mechanical loads, or, even more disadvantageously, to overlapping of the cutting edges. The latter can lead to damage during the start-up of the mill and sometimes even occurs not so rarely.

[0009] It is also disadvantageous that adjusting screws, threads, lock nuts, etc. used for adjustment are additional components and are contrary to the hygienic design of the grinding machine.

[0010] Additionally, this type of adjustment may limit the lower size of the mill because as the mill becomes smaller, the individual components will also need to be smaller, making adjustment more difficult.

[0011] Therefore, in general, some "errors" may be introduced when making adjustments.

[0012] Similar disadvantages also apply to impact cross mills (see

[0013] 16, www.fritsch.de), the product description of which is hereby incorporated by reference. Impact cross mills have a grinding machine similar to a cutting mill, but they generally have a larger grinding gap width than in a cutting mill. As a result, the comminution effect can be more strongly based on the impact effect. Summary of the invention

[0014] The object of the present invention is to provide a laboratory mill, in particular a cutting mill or a cross impact mill, which is easy to use and requires little expertise and operating effort on the part of the user.

[0015] A further object of the present invention is to provide a laboratory mill, in particular a cutting mill or a cross impact mill, which is cost-effective, less prone to failure and requires less maintenance.

[0016] Another object of the present invention is to provide a laboratory mill, in particular a cutting mill or a cross impact mill, which is easy to clean and allows the user to change the width of the grinding gap very easily and without error.

[0017] A further object of the present invention is to provide a laboratory mill, in particular a cutting mill or a cross impact mill, which can be designed to be particularly small and compact.

[0018] The object of the invention is achieved by the subject matter of the independent claims. Advantageous developments of the invention are defined in the dependent claims.

[0019] According to the invention, a laboratory mill for comminuting and grinding materials is provided, which comprises an equipment housing and a grinder housing in which a rotor grinder is arranged. The grinder housing can be made of solid metal, for example aluminum or stainless steel. The grinder housing defines a grinding chamber, in particular a substantially cylindrical one, into which a rotor grinder consisting of a rotor and at least one stationary matching element is inserted. The rotor or its drive defines the central axis of the grinding chamber or the grinder housing with its axis of rotation. The grinder housing can have an axial end side on the rear drive side, by means of which the grinder housing can be flange-connected to the rear part of the equipment housing. The grinder housing has, in particular, a front axial end side opposite the grinder drive, from which a user can axially intervene in the grinder.

[0020] The rotor grinder is thus inserted into a grinding chamber of a grinder housing, wherein the rotor can be plugged onto a drive shaft. At least one stationary mating element is inserted into the grinder housing parallel to the rotor in order to form a defined grinding gap between the rotor and the at least one mating element, in which the material to be ground is comminuted when the rotor rotates relative to the at least one mating element. If necessary, the grinder has a rotor with a plurality of, for example two, three, four or more cutting knives or impact bars, and the laboratory mill has a plurality of, for example two, three, four or more mating elements, which are arranged around the rotor along the rotor circumference. In the present application, "at least one" therefore means one or more, in particular two, three, four or more, such components.

[0021] The laboratory mill is in particular designed as a laboratory-scale cutting mill or impact cross mill. Thus, the rotor can be designed as a cutting rotor and the at least one mating element can be designed as a stationary mating blade of a cutting mill, or the rotor can be designed as an impact rotor and the at least one mating element can be designed as a stationary mating impact bar of an impact cross mill.

[0022] The grinding machine drive is preferably accommodated in the device housing and drives the rotor via a drive shaft extending axially into the grinding chamber. The rotor and / or one or more mating elements extend axially in the grinding chamber, preferably from the rear motor-side end of the grinding chamber to the front end opposite the drive, in particular to the grinding machine housing door. The drive shaft can, for example, enter the grinding chamber through a shaft through-hole at the motor-side end of the grinding chamber.

[0023] The grinding machine housing or the grinding chamber is open at the front end, i.e., the end opposite the motor-side end, thereby forming an axial user access opening, through which the user can insert and remove the rotor, matching elements and, if necessary, other replaceable grinding machine parts, for example in order to clean, maintain or replace these parts and also to clean the grinding chamber.

[0024] For operating the laboratory mill, the user access opening is closed by a grinder housing door, which is pivotably suspended on the grinder housing, for example, by hinges. The grinder housing door has an open and a closed state, wherein the user has access to the grinder in the open state, and the laboratory mill can be safely operated when the grinder housing door is closed. The laboratory mill can also have a smaller axial or radial grinding material charging opening, for example with a charging funnel, through which grinding material can be continuously fed during operation. The grinder housing door can have a door lock, by which the grinder housing door can be locked in the closed state, and a safety device, which ensures the locking of the grinder housing door during operation. Reference is made to a parallel patent application entitled "Laboratory Mill" filed on the same date by the same applicant, which is incorporated herein by reference.

[0025] When the grinding machine housing door is open, at least one or more stationary counter-elements can advantageously be inserted or pushed axially into the grinding machine housing.

[0026] For this purpose, the grinding machine housing forms with one or more mating elements a respectively radially acting, form-fitting, axially displaceable guide, for example in the form of an axially displaceable tongue-and-groove guide as a linear guide.

[0027] The corresponding radial form fit forms a support against the radial inward movement of the mating element toward the rotor, so that the radial inward movement of the corresponding mating element toward the rotor is limited. Therefore, the form fit support against the radial inward movement of the corresponding mating element toward the rotor is formed, for example, by a groove guide.

[0028] Here, one or more mating elements are preferably inserted only loosely into the grinding machine housing. The radial end position of one or more mating elements is limited in the grinding machine housing, especially in a form-fitting manner, especially to prevent radial inward movement, thereby defining the minimum size of the grinding gap. Therefore, one or more mating elements are inserted axially into the linear guide in a radial form-fitting manner, and the grinding gap is defined by the radial form-fitting of the axially extending linear guide. In particular, the linear guide limits the radial inward movement of one or more mating elements. In particular, no other radial and / or axial fixation, such as a screw connection, is required, and / or no adjustment mechanism and / or radial tensioning, such as that achieved by bolts, etc., is required. During the operation of the laboratory mill, one or more mating elements are axially inserted into the linear guide, and / or are radially fixed only by form-fitting during installation. In particular, during the operation of the laboratory mill, one or more mating elements are not tightened. The mating element cannot be adjusted radially, such as by a threaded pin, in particular, in order to adjust the grinding gap (cutting gap or impact gap) between the rotor and at least one mating element. The definition of the width of the grinding gap is achieved only by the component geometry and the linear guide or the radial form fit of the linear guide. The linear guide is in particular a uniaxial linear guide. Therefore, the width of the grinding gap cannot be adjusted continuously by the user, but is fixedly implemented at the manufacturing end according to the structure and is thus fixedly predefined. For example, the selection of the width of the grinding gap can be carried out by using different rotors with different rotor diameters or by means of mating elements of different widths, instead of manually adjusting the width of the grinding gap by the user by radially adjusting one or more mating elements.

[0029] This ensures a very simple use of the laboratory mill, since manual adjustment of the grinding gap by radial adjustment of one or more mating elements is not necessary and is omitted. If one or more mating elements become worn, they are simply replaced by new ones (the so-called single-use principle). In order to select the desired width of the grinding gap, the user has one, two or more other rotors with different diameters in stock, which can be used to discretely change the width of the grinding gap by simply replacing them. It is obvious that several discrete values ​​can thus be selected for the width of the grinding gap.

[0030] In this way, incorrect operating procedures by the user, in particular incorrect setting of the grinding gap, are excluded from the structural aspect, so that the laboratory mill can also be operated by less experienced users.

[0031] The subject matter of the present invention also includes a laboratory mill group consisting of a laboratory mill and at least two, preferably at least three or more rotors with predefined different diameters, or at least two or preferably at least three groups of mating elements with different widths, wherein the width of the grinding gap between the rotor currently inserted into the grinding chamber and at least one mating element is selected not by radially adjusting at least one mating element, but by replacing the rotor or the mating element with another rotor with another diameter or another mating element with another width.

[0032] If a rotor with a rotor base body and a separate cutting blade or a separate impact strip is used, and the cutting blade or the impact strip is screw-fastened to the rotor base body, then preferably also an exact radial positioning of the cutting blade or the impact strip on the rotor should be ensured in order to define the grinding gap exactly on the manufacturer's side, especially since one or more mating elements cannot be adjusted radially but are guided in a single discrete radially predetermined position by a linear guide. For this purpose, the rotor base body can have a tongue-and-groove connection with the cutting blade or the impact strip for radial locking, and / or the cutting blade or the impact strip can be screw-fastened to the rotor base body by means of a positioning screw.

[0033] However, inserting one or more stationary mating elements into the linear guide with radial form fit has a further advantage. As a result, one or more mating elements and thus also the grinding machine and the entire laboratory mill can be designed very compactly, since adjusting elements such as threaded pins and screws on the mating elements can be omitted, so that a simple, cost-effective and compact synergy can be achieved.

[0034] Preferably, the grinding machine housing has at least one or more receiving guide slots for one or more mating elements extending axially along the rotor and radially. The one or more receiving guide slots are radially inwardly toward the rotor and open on the axial end side of the grinding machine housing. Through the end side opening of the receiving guide slot, the corresponding mating element can be manually inserted or pushed into each corresponding receiving guide slot axially through the open end side. One or more mating elements extend radially inwardly from the corresponding receiving guide slot into the grinding chamber at least with an axial edge (mating cutting edge or mating impact edge) so as to crush the grinding material in the outer cover area of ​​the periphery of the grinding chamber between the rotor and at least one axial edge. Preferably, the axial linear guide between the one or more receiving guide slots and the corresponding one or more mating elements forms an internal radial support for each corresponding mating element, so that its radial inward movement in the direction of the rotor is limited and a precisely defined grinding gap is ensured.

[0035] One or more receiving guide slots can each have at least one guide groove extending axially and transversely to the receiving guide slot as a guide rail, and one or more mating elements can each have at least one tongue element movable in at least one guide groove. However, the groove and tongue of the axially movable tongue-and-groove guide formed in this way can also be configured inversely, that is, one or more grooves in the mating element and one or more tongues in the receiving guide slot. Thus, the tongue-and-groove guide forms the guide rail of the linear guide.

[0036] Preferably symmetrical axial guide grooves preferably extend on both sides of the one or more receiving guide slots. Thus, the one or more receiving guide slots can have a substantially cross-shaped cross section together with the guide slots on both sides. Here, the linear guide or receiving guide slot and / or guide slot respectively extends axially and linearly from the rear drive-side end to the front door-side end. The one or more linear guides for the one or more mating elements or guide slots are preferably arranged transversely on both sides of the receiving guide slot.

[0037] Such linear guides, receiving guide slots and guide grooves can be introduced, for example, at reasonable expense into a solid metal grinding machine housing.

[0038] Preferably, one or more mating elements each have two flat sides, which extend axially and radially in each corresponding receiving guide slot and abut against the receiving guide slot when the one or more mating elements are inserted into each corresponding receiving guide slot. The term "radial" or "extending in the radial direction" should not be strictly understood in a mathematical way here, but refers to a direction extending "substantially" radially, i.e. inwardly toward the rotor axis or outwardly away from the rotor axis. Therefore, the "radial" direction in this sense does not necessarily have to intersect the rotor axis mathematically exactly. According to one embodiment, at least one, preferably at least two or more transverse holes are provided through the two flat sides of one or more mating elements, and a transverse pin is fixed in each transverse hole, for example in a press fit. One or more transverse pins form one or more tenon elements, which are radially guided in each corresponding guide groove and can be axially moved to form a corresponding linear sliding guide. Preferably, groove and tongue guides are provided on both sides of one or more mating elements.

[0039] The radial limitation of the movement for forming a fixed defined width of the grinding gap can be designed as follows. In order to limit the radially inward movement, one or more mating elements can be supported radially inwardly in the direction of the rotor on the radially inner side wall of the respectively corresponding guide groove of the tongue-and-groove guide, thereby limiting the movement of the one or more mating elements radially inwardly in the direction of the rotor.

[0040] In order to limit the radial outward movement, one or more engaging elements can be supported radially outward in the direction away from the rotor on the radially outer side wall of the corresponding guide groove of the tongue-and-groove guide, thereby limiting the radial outward movement of the one or more engaging elements in the direction away from the rotor, or the longitudinal side of the one or more engaging elements facing away from the rotor can be directly or indirectly supported on the radially outer bottom of the respective corresponding receiving guide slot, thereby limiting the radial outward movement of the one or more engaging elements also in the direction away from the rotor. In this way, a clearance fit of the linear guide can be achieved in the radial direction with a small clearance, for example from almost zero to a maximum of + / - one tenth, preferably + / - a few percent, in order to structurally define the width of the grinding gap in a fixed manner.

[0041] In particular, the receiving guide slots can each have an axial hole at the bottom located radially on the outside, into which an axially extending support pin is inserted. The longitudinal side of one or more mating elements facing away from the rotor is supported on the support pin and the support pin is supported in an axial hole on the grinding machine housing in order to limit the radial outward movement of at least one mating element in the direction away from the rotor. This has the advantage that loads acting radially outward during grinding can be removed along the longitudinal pin in a long line, wherein the axial support pin can be designed, for example, as a hardened steel pin, for which a large area is then provided in the axial hole for removing the load from the grinding machine housing. This is particularly advantageous in small laboratory grinding machines.

[0042] When the mating element is inserted into the corresponding receiving guide slot, the two end sides or the narrow sides of the end sides of one or more mating elements extend in particular in a plane transverse to the rotor axis. A pulling opening can be provided in the mating element near at least one of the two end sides, for example a transverse hole through the flat side, so that a pulling tool, for example a pulling hook, can be introduced into the pulling opening in a form-fitting manner, in particular can be hooked into the pulling opening, so that when the grinding machine housing door is opened, the mating element can be pulled axially out of the grinding machine housing or from the corresponding receiving guide slot by means of the pulling tool. This allows the user to easily remove one or more mating elements from the grinding machine housing, for example for cleaning, turning over or replacing them.

[0043] It is particularly simple if the pulling opening is positioned in the radial direction on the guide groove, so that the pulling opening is accessible by means of a pulling tool through the guide groove that is already present.

[0044] Preferably, one or more mating elements each have a base body in the form of an elongated flat plate or strip. The base body is in particular substantially square. Thus, one or more mating elements have two axially and radially extending flat sides, two longitudinal sides extending axially and transversely to the flat sides, and two end sides extending transversely to the flat sides and the longitudinal sides, i.e. in a plane transverse to the rotor axis and in particular substantially parallel to the axial end side of the grinding machine housing. Preferably, the aspect ratio between the width and thickness of the base body is at least 2 or at least 3.

[0045] At least one longitudinal edge between the flat side and the adjacent longitudinal side forms a cutting edge or impact edge of a corresponding mating element, which interacts with the cutting edge or impact edge of the rotor in order to crush the grinding material therebetween, wherein the longitudinal edge extends axially within the grinding chamber when at least one mating element is inserted into at least one receiving guide slot of the grinding machine housing.

[0046] Preferably, one or more mating elements are designed in principle as disposable parts, that is, they are not reground, because otherwise the width of the grinding gap will no longer be consistent, but they can be flipped and can therefore be used multiple times. For this purpose, one or more receiving guide slots can be formed in a mirror-symmetrical manner. In addition, one or more mating elements can be designed to be rotationally symmetrical or flippable by 180° with respect to at least one, two or three of the following axes:

[0047] about an axis extending transversely to the flat side,

[0048] about an axis extending transversely to the longitudinal sides and / or

[0049] about an axis extending transversely to the end side,

[0050] Thus, one or more mating elements can be inserted into the corresponding receiving guide slot not only in one, but also in at least two, three or four orientations.

[0051] One or more mating elements can therefore preferably be inserted into the grinding machine housing in a first orientation and in a second orientation flipped relative to the first orientation and / or in a third orientation flipped relative to the first orientation and the second orientation and / or in a fourth orientation flipped relative to the first orientation, the second orientation and the third orientation, so that the first and second and / or the third and / or the fourth longitudinal edge of at least one mating element can be used as a cutting edge or impact edge. In other words, one or more mating elements can be flipped at least once, twice or three times and can be used at least two, three or four times by flipping.

[0052] Preferably, for flipping, there can be at least four, in particular axially colinear, transverse holes passing through the flat side of the at least one mating element, wherein a through transverse pin protruding to both sides as a tenon element is fixed in each of the two axially inner transverse holes, for example by press fit, and wherein the two axially outer holes remain free as pulling openings.

[0053] The mating elements inserted with a uniaxial linear guide can advantageously be designed to be relatively small, especially because the mating elements are not tightened and more complex components such as threaded pins and bolts for adjustment and tightening can be omitted. However, they can also be designed to be larger. Preferably, the base body of the axially insertable mating element can have a length of between 20 mm and 200 mm, preferably between 30 mm and 60 mm, a width of between 8 mm and 60 mm, preferably between 15 mm and 30 mm and / or a thickness of between 3 mm and 25 mm, preferably between 4 mm and 8 mm.

[0054] An elastomeric pressure element, for example in the form of an elastomeric seal, can be fastened to the inner side of the grinding machine housing door, by means of which one or more mating elements are axially clamped against the axial motor-side end of the receiving guide slot when the grinding machine housing door is closed. Residual movements due to play in the linear guide can thereby be prevented.

[0055] The elastomeric pressing element can be designed, for example, as an annular seal (O-ring) and can be fixed, for example, in an annular groove on the inner side of the grinding machine housing door. The elastomeric seal can perform a dual function, namely, on the one hand, sealing the guide groove and / or the grinding chamber annularly at the end face and, on the other hand, clamping the mating element or elements in a fixed manner.

[0056] Preferably, the grinding chamber can be formed in the grinding machine housing as a substantially cylindrical, in particular substantially cylindrical cavity, and radially transitions downward into a grinding material outlet channel, through which the crushed grinding material can flow into a grinding material collection container. The grinding chamber and the grinding material outlet channel can be separated by an arc-shaped screen plate, in particular in the absence of a stable screen box, through which the crushed grinding material can flow downward from the grinding chamber into the grinding material outlet channel. The arc-shaped screen plate and the rotor can be removed axially from the grinding machine housing when the grinding machine housing door is opened. For this purpose, the arc-shaped screen plate can be inserted into the grinding machine housing and placed there between the grinding chamber and the grinding material outlet channel. In an advantageous manner, the grinding machine housing is particularly free of tabs in the area below the screen plate on the end side of the door side in front of it, i.e., it does not have tabs that cross the grinding material outlet channel. As a result, the grinding chamber and the grinding material outlet channel can be cleaned jointly and unimpeded from the end side of the grinding machine housing, so as to clean the grinding machine housing when the grinding machine housing door is opened and the rotor and the curved screen plate are removed. The grinding chamber and the grinding material outlet channel therefore have a common, unified front end opening.

[0057] According to one aspect of the invention, a laboratory mill, in particular configured as a cutting mill or a cross impact mill, may comprise:

[0058] an apparatus housing having a grinding machine housing, wherein the grinding machine housing delimits a substantially cylindrical grinding chamber and has a front axial end side opposite the grinding machine drive,

[0059] A rotor grinder in a grinding chamber of a grinding machine housing, wherein the rotor grinder has a rotor defining a rotor axis and at least one stationary mating element, preferably a plurality, in particular two, three, four or more stationary mating elements, wherein when the rotor rotates, the material to be ground is comminuted between the rotor and the stationary mating element or elements, which are preferably arranged along a circumferential line around the rotor,

[0060] a grinding machine drive in the device housing for driving the rotor in the grinding chamber,

[0061] a grinding machine housing door for closing the grinding machine housing on an axial end side, wherein the grinding machine housing door has an open and a closed state, wherein a user has axial access to the grinding machine in the open state of the grinding machine housing door,

[0062] wherein the grinding chamber is formed in the grinding machine housing in the form of a substantially cylindrical cavity and transitions downwardly into a grinding material outlet channel through which the ground material can flow into a grinding material collecting container, wherein the grinding chamber and the grinding material outlet channel are separated by an arc-shaped sieve plate, in particular without a sieve box, through which the ground material can flow downwardly from the grinding chamber into the grinding material outlet channel, and

[0063] Therein, at least one or more, preferably at least two or at least three axial conical pins protrude from the grinding machine housing door, which are swung under the arc-shaped screen plate by a pivoting movement when the grinding machine housing door is closed and support the screen plate downward when the grinding machine housing door is closed.

[0064] Thus, a simple flat screen plate, for example punched out of a perforated plate and subsequently bent, can advantageously be introduced into two lateral grooves in the grinding machine housing without a screen box and without further lateral reinforcement and supported from below by a conical pin on the end edge facing the grinding machine housing cover. By means of the conical pin as a lower support on the grinding machine housing door, its pivoting closure without jamming can be ensured. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] The invention is explained in more detail below on the basis of exemplary embodiments and with reference to the drawings, wherein identical and similar elements are partly provided with identical reference symbols and features of different exemplary embodiments may be combined with one another.

[0066] in:

[0067] Figure 1 shows a three-dimensional view of a cutting mill according to one embodiment of the present invention,

[0068] Figure 2 It shows that Figure 1 A view of the grinder housing with transparency,

[0069] Figure 3 It shows that Figure 1 A view of the grinder housing with the door opened,

[0070] Figure 4 Shows Figure 1 Front view of a cutting mill without the grinder housing door,

[0071] Figure 5 Shows Figure 4 The enlarged view of the local A in

[0072] Figure 6 shows a three-dimensional view of a cutting mill without a grinding machine housing door according to another embodiment of the invention,

[0073] Figure 7Shows Figure 6 Front view of the cutting mill,

[0074] Figure 8 Shows Figure 7 The enlarged view of the local A in

[0075] Fig. 9 Shows Figure 1 Longitudinal section of a cutting mill,

[0076] Fig.10 A three-dimensional view showing a stationary mating element,

[0077] Fig.11 Shows Fig.10 A top view of the flat side of the mating element in FIG.

[0078] Fig.12 Shows Fig.10 A front view of the longitudinal side of the mating element,

[0079] Fig.13 Shows Fig.10 end view of the mating element,

[0080] Fig.14 shows a three-dimensional view of a rotor according to an embodiment of the present invention,

[0081] Fig.15 shows a three-dimensional view of a rotor according to another embodiment of the present invention,

[0082] Fig.16 shows a horizontal section through the grinding machine housing,

[0083] Fig.17 shows a vertical section through the grinding machine housing,

[0084] Fig.18 shows a three-dimensional view of a cutting mill without a grinder housing door according to another embodiment of the invention,

[0085] Fig.19 Shows Fig.18 Front view of the cutting mill,

[0086] Fig. 20 Shows Fig.19 The enlarged view of the local A in

[0087] Fig.21 Shows Figure 6 A three-dimensional view of the base of the cutting mill viewed diagonally from below and to the left.

[0088] Fig. 22 Shows Figure 6A three-dimensional view of the base of the cutting mill viewed from the right side diagonally above.

[0089] Fig.23 An exploded view of a conventional cutting mill is shown. DETAILED DESCRIPTION

[0090] Reference Figure 1-9 A laboratory mill 1 is shown, in the present example in the form of a cutting mill. The laboratory mill 1 has an apparatus housing 12 with a user display 14 for the user to input grinding parameters into a control device (not shown) of the laboratory mill 1. A grinder housing 16 is arranged on the front side 12a of the apparatus housing 12, which can be closed at the front side (axially) by means of a grinder housing door 18. The grinder housing door 18 is designed as a swing door and can be swung open and closed about a hinge 20. When the grinder housing door 18 is closed, it can be locked by means of a door lock 22, such as Figure 1 When the grinding machine housing 16 is closed, the grinding material can be fed through the charging funnel 24 and the grinding material charging opening 26 ( Figures 21 to 22 ) is injected, so that the material to be ground can be continuously fed and comminuted during operation of the cutting mill 1. When the locking element 22 is unlocked, the user can pivot the grinder housing door 18 open to gain access to the rotor grinder 30 located in the interior of the grinder housing 16 or the grinding chamber 32.

[0091] When the grinding machine housing door 18 is fully pivoted open, the user can thus axially access the essentially cylindrical grinding chamber 32 and the rotor grinder 30 arranged therein through the axial user access opening 38, which has a rotor 34 that rotates coaxially with the drive axis or rotor axis X and a plurality of axially extending stationary mating elements 36 that are arranged annularly around the rotor 34. This exemplary embodiment shows a cutting mill, so that the rotor 34 is designed as a cutting rotor and the stationary mating elements 36 are designed as stationary mating knives. In a correspondingly designed impact cross mill, the rotor 34 is designed as an impact rotor with impact strips, and the stationary mating elements 36 are designed as mating impact strips.

[0092] The rotor 34 is preferably plugged onto the drive shaft 2 and screwed axially and driven via form-fitting elements, the drive shaft 2 being driven from behind by the drive motor 4. To this end, the drive shaft 2 extends through the central opening 6 between the rear part 12 b of the device housing 12 and the grinding machine housing 16 flanged thereto at the front and also defines a coaxial rotor axis X ( Fig. 9 ).

[0093] When the grinder housing door 18 is fully open, the user can loosen and axially remove the rotor 34 from the drive shaft 2 and pull it out axially through the front axial user access opening 38 of the grinder housing 16. During operation, the rotor 34 rotates and the grinding material is fed to the rotor grinder 30 via the charging funnel 24 through the radial grinding material charging opening 26 and is comminuted by cutting and / or impacting between the rotor knives 40 or the impact bars of the rotor 34 and the stationary mating elements 36. The comminuted grinding material then flows downwards, for example, through a screen 42 into a grinding material collecting container 44.

[0094] The stationary mating elements 36 are fixed in the grinding machine housing 16, i.e. they are not radially adjustable, i.e. they are radially fixedly positioned. In the present example, they can be flipped in four different orientations by being constructed with multiple rotational symmetry and can be inserted into the grinding machine housing 16 by conversion, so that they can be used four times. Nevertheless, in order for the user to be able to select different widths of the grinding gap according to the material to be ground, the laboratory mill 1 can be provided with different rotors 34 with different diameters, for example. For example, each laboratory mill 1 is equipped with a group consisting of three different rotors 34, which work together with the radially non-adjustable mating elements 36, for example, to provide three grinding gaps of 0.2 mm, 0.6 mm and 1 mm in width. Here, the same cutting tool 40 or impact strip can be used on different rotors 34, which can also be flipped doubly. Only the rotor base body 35, which can be easily manufactured, has different radial dimensions accordingly. The different discrete widths of the grinding gap are ultimately determined by these radial dimensions of the rotor base body 35, so that the selectable width of the grinding gap does not result from an undefined dimension set by the user, but is dimensionally clearly defined by the production of the rotor base body 35, for example by cutting. For this purpose, the rotor blades 40 or the impact strips are clearly and accurately defined in their position on the rotor 34, for example by an axially extending tongue-and-groove connection 46 or by a locating screw 48. The rotor blades 40 or the impact strips are precisely machined in terms of geometry, which can be achieved in a simple and cost-effective manner, since they have to be ground anyway and can therefore be machined with high precision in the final process step.

[0095] Thus, the laboratory mill 1 does not allow a continuous radial adjustment of the mating elements 36 and thus of the width of the grinding gap, but it provides, for example, two, three or more discrete numbers of discrete values ​​of the width of the grinding gap, which can be selected, for example, from the supplier's catalog by means of rotors 34 of different diameters. Alternatively, discrete values ​​of the width of the grinding gap can also be provided by means of different groups of mating elements 36 with different widths.

[0096] The rotor 34 is axially plugged onto the drive shaft 2 via the user access opening 38. The laboratory mill 1 according to the present exemplary embodiment has, for example, four stationary mating elements 36, which, when the grinder housing door 18 is open, are inserted from the front axial end side 16a into four long axial receiving guide slots 52 in the grinder housing 16. The receiving guide slots 52 form a uniaxial, axially extending linear guide for the stationary mating elements 36.

[0097] Reference Figure 10-13 , the mating element 36 consists of a cuboid-shaped base body 54, which has two flat sides 54a, two longitudinal sides 54b and two end sides 54c and is one-piece, for example made of hardened steel, tungsten carbide or ceramic material. In this example, four transverse holes 56 extend through the flat side 54a, which can be implemented identically for simplicity. The guide pins or dowel pins 58 are pressed into the two axially inner transverse holes 56a by means of a press fit. Therefore, the axial linear guide 62 for the mating element 36 in the grinding machine housing 16 is constructed in the form of a groove and tongue linear guide, with two sliding bearings in this example. The two axially outer holes 56b remain open and serve as pulling openings 60, so that the mating element 36 can be pulled out of the receiving guide slot 52 again, for example, using a pulling tool (not shown) hooked into the corresponding front pulling opening 60.

[0098] The engagement element 36 shown here is of very simple design and has no adjustment elements, such as threaded holes for fastening screws, because they are positioned radially precisely in the grinding machine housing 16 by means of the linear guide 62 in a manner determined by the manufacturing conditions (dimensions that cannot be changed by the user). The engagement element 36 can be easily manufactured and designed to be relatively small, so that a relatively compact laboratory mill 1 can be constructed. In this exemplary embodiment, the engagement element 36 is only 40 mm long, 20 mm wide and 5 mm thick. The diameter of the dowel 58 is 5 mm, and its projection on both sides, i.e. the engagement depth of the tongue-and-groove linear guide, is 2.5 mm.

[0099] The cuboid base body 54 of the engagement element 36 is formed in one piece from a cutting material, for example hardened steel, and the engagement element 36 is designed in a 180° rotationally symmetrical manner about all three surface normals. All four longitudinal edges 54d between the flat side 54a and the longitudinal side 54b are designed as identical cutting edges. Thus, the engagement element 36 can be turned over three times and inserted axially into the receiving guide slot 52 in four different orientations, i.e. used four times.

[0100] The axial receiving guide slots 52 are each open toward the grinding chamber 32 and have guide grooves 64 extending axially transversely from the receiving guide slots 52 on both sides, which form linear guides 62 in the form of tongue-and-groove linear guides with the tongue elements or pins 58 of the mating element 36 .

[0101] exist Figure 4-5 In the embodiment shown, the fit between the tenon 58 and the guide groove 64 is made with a clearance fit, for example, with a clearance of + / -5 / 100, so that the tenon element 58 not only radially inwardly, but also radially outwardly constitutes a radial support for the matching element 36. The tenon element 58 engages the radially inner rolling surface 64a of the corresponding guide groove 64 from behind and is supported radially inwardly on the rolling surface. The radially inner generatrix 58a of the tenon element 58 forms an inwardly acting stop together with the rolling surface 64a, and the radially outwardly pointing generatrix 58b of the tenon element 58 forms an outwardly acting stop for the linear guide 62 of the matching element 36 together with the radially outer rolling surface 64b. Therefore, the free space 68 located radially outside remains vacant in the receiving guide gap 52. As a result, additional undercut grooves can be saved during milling. On the other hand, the load acting outwardly is reduced by the relatively short generatrix 58b of the tenon 58. Accordingly, the linear guide 62 has two axially spaced radial load reduction locations in the current example. If at least two axially spaced-apart radial load relief points are used, tilting moments can be avoided and a high gap parallelism can be ensured.

[0102] Reference Figures 6 to 8 In the embodiment shown in the figure, the axially extending guide groove 64 can also be made with a significant radial interference with respect to the radially outer free space 69. In this case, only a radially inwardly acting stop is formed between the tenon element 58 and the guide groove 64. The radially outwardly acting stop is formed by the longitudinal side 54b located radially outside. In this example, a support pin 72 (for example a hardened steel pin 72) extending in the axial hole 70 forms a matching stop located radially outside. Although this variant requires an additional hole 70 and an additional support pin 72, the load acting radially outward for this purpose is reduced over a greater length, preferably over the radially outer longitudinal side 54b of the matching element 36 or the entire length of the support pin 72. Nevertheless, additional undercut grooves can be omitted in the milling of the accommodating guide seam 52. The groove geometry can thus be simply maintained. The support pin 72 can be pressed into the corresponding axial hole 70 by means of a press fit, because these support pins do not have to be removed by the user.

[0103] In both embodiments, the stationary mating element 36 is therefore secured against movement in the radial direction inwards, i.e. towards the rotor 34, by means of a tongue-and-groove linear guide, or more precisely by means of a tongue element 58 guided in a guide groove 64. The axial linear guide 62 therefore does not allow the inserted mating element 36 at least no freedom of movement in the radial direction towards the rotor 34.

[0104] exist Figure 4-5 In the embodiment shown, the tongue element 58 and the guide groove 64 also act as a limit stop away from the rotor. Figures 6 to 8 In the embodiment shown, the stop against a movement directed radially outwards or away from the rotor 34 is formed by the support pin 72. Thus, the axial linear guide 62 preferably also has no freedom of movement in the radial direction away from the rotor 34 for the inserted mating element 36.

[0105] In both cases, the loosely inserted fitting element 36 is preferably radially fixedly positioned in the corresponding receiving guide slot 52 in both directions radially inward and radially outward, except for the radial clearance predetermined by the manufacturing tolerance, so that the width of the grinding gap is fixedly predefined and no adjustment is required and / or cannot be performed.

[0106] Another advantage of not having a radial adjustment of the mating element 36 is that this would require, in conventional cutting mills, a rotation of the rotor for adjustment in such a way that the rotor blade 40 and the mating element 36 are precisely aligned in order to adjust the cutting gap. This can be omitted in the present invention. As a result, the rotary drive of the rotor 34 can even be locked in a form-fitting manner when the grinder housing door 18 is open as a safety function. The present invention can therefore be particularly advantageous in combination with a form-fitting locking of the grinder drive, as described in a patent application filed on the same day by the same applicant under the title “Laboratory Mill”, although this is not essential. The laboratory mill 1 can, for example, have a form-fitting coupling which is actuated by the door lock 22 by means of a mechanical actuation chain and which locks the grinder in a form-fitting manner when the grinder housing door 18 is open. For further details, reference is made to the aforementioned parallel patent application.

[0107] Advantageously, the mating element 36 can be easily turned over and / or replaced by inserting it into the receiving guide slot 52 or the linear guide 62 or pulling it out again from the receiving guide slot 52 or the linear guide 62, in particular because no threaded pins or screws are required for adjustment and / or tightening. In addition, when the grinding machine housing door 18 is open, all components of the rotor grinder 30, in particular the rotor 34 and the mating element 36 as well as the curved screen 42 can be easily pulled out axially from the grinding chamber 32, so that the grinding chamber 32 can be easily cleaned of grinding dust, for example by sweeping it out. Even if grinding dust adheres to the mating elements 36, these can be pulled out with sufficient extraction force by means of the pulling opening 60. The laboratory mill 1 is therefore resistant to dirt in this respect.

[0108] The grinder housing door 18 can additionally have an elastomeric seal 74 on its inner side 18a facing the grinding chamber 32, for example an annular seal in a circumferential groove 76. The annular seal 74, for example an O-ring, seals the user access opening 38 or the grinding chamber 32 in an annular manner when the grinder housing door 18 is closed, so that no grinding dust can escape. The annular seal 74 advantageously extends radially around the grinding chamber 32 and the guide groove 64 of the receiving guide slot 52. As a result, the guide slot 64 can be kept largely free of grinding dust. For this purpose, the front end side 54c of the engagement element 36 ends essentially flush with the front side 16a of the grinder housing 16 or with a slight interference. The elastomeric seal 74 clamps the engagement element 36 in the receiving guide slot 52 relative to the rear end of the receiving guide slot 52, so that even in the case of a slight fit clearance of the linear guide 62, the engagement element 36 is firmly fixed when the grinder housing 16 is closed and does not make a rattling sound.

[0109] Reference Figure 18-20 The elastomer seal 74 can also be constructed as a special flat seal 74 ′ and have a lug 78, which can axially overlap and completely close the front end side of the guide groove 64. Due to the larger surface of the lug 78, more force can also be applied to the mating element 36 in the axial direction.

[0110] Three conical pins 80 are fixed to the grinder housing door 18 slightly below the grinding chamber 32, which protrude from the inner side 18a of the grinder housing door 18. When the grinder housing door 18 is closed, in particular by a pivoting movement about the hinge 20, the conical pins 80 pivot under the curved screen plate 42 in the pivoting path and finally support the screen plate 42 downward. As a result, a supporting tab for the screen plate 42, which is fixedly fixed to the grinder housing 16 and laterally covers the user access opening 38, can be omitted. It has been found that the use of conical pins 80 in combination with the shape of the curved screen plate 42 is particularly advantageous for the pivoting path.

[0111] See also Figure 21-22 , the grinding machine housing 16 can include a one-piece base body or housing block 17 and can be milled integrally from a metal block, for example. Here, the receiving guide slit 52, the guide groove 64, the grinding chamber 32 and / or the grinding material outlet channel 82 connected to the grinding chamber at the bottom are processed from the metal block as a unified, interconnected cavity 84. The cavity 84 is preferably milled into a cylindrical shape with a complex generatrix 84a. The front end side of the cylindrical cavity 84 is preferably completely open. In other words, the unified cylindrical cavity 84 composed of the interconnected receiving guide slit 52, the guide groove 64, the grinding chamber 32 and / or the grinding material outlet channel 82 connected to the grinding chamber at the bottom is completely open on the front end side 17a of the housing block 17 with a unified common opening surface, which is defined by the generatrix 84a of the cylindrical cavity 84. As a result, on the one hand the grinding machine housing can be produced cost-effectively, for example milled from an aluminum or stainless steel block, and on the other hand a compact small laboratory mill 1 can be constructed with the small grinding machine 30 .

[0112] The screen plate 42 can be produced relatively simply and flexibly from a simple perforated plate, since it allows access to both the essentially cylindrical grinding chamber 32 and the relatively wide grinding material outlet channel 82 without crosspieces, despite the uniformly wide user access opening 38. When the grinder housing door 18 is open, the entire chamber 84 formed by the grinding chamber 32 and the grinding material outlet channel 82 formed uniformly therewith is open unhindered on the front end side 16a of the grinder housing 16. The conical pins 80 prevent the screen plate 42 from buckling during operation. The screen plate 42 is inserted between the mating element 36 and the bearing surface 86 between the grinding chamber 32 and the grinding material outlet channel 82.

[0113] It is obvious to a person skilled in the art that the embodiments described above are to be understood as exemplary and that the invention is not limited to these embodiments but may be varied in many ways without departing from the scope of protection of the claims. Components described in the singular are also to be understood as plural and vice versa. It can also be seen that the features individually define important components of the invention independently of whether they are disclosed in the description, claims, drawings or elsewhere, even if they are described together with other features.

Claims

1. A laboratory mill (1) for comminuting a material to be milled, in particular configured as a cutting mill or an impact cross mill, the laboratory mill comprising An apparatus housing (12) having a grinding machine housing (16), wherein: The grinding machine housing (16) defines a grinding chamber (32) and has an axial end side (16a). A rotor grinder (30) is located in the grinding chamber (32) of the grinder housing (16), wherein the rotor grinder (30) includes a rotor (34) and at least one mating element (36), wherein the rotor (34) defines a rotor axis (X), wherein when the rotor (34) rotates, a grinding material is comminuted between the rotor (34) and the at least one mating element (36), A grinding machine drive (2, 4) for driving a rotor (34) in a grinding chamber (32), a grinding machine housing door (18) for closing the grinding machine housing (16) at an axial end side (16a), The at least one mating element (36) is axially insertable into the grinding machine housing (36) when the grinding machine housing door (18) is open.

2. The laboratory mill (1) according to claim 1, wherein: The at least one engagement element (36) is axially guided in the grinding machine housing (16) by means of a radial form fit.

3. The laboratory mill (1) according to claim 2, wherein: The radial form fit forms a support that prevents the at least one engagement element (36) from moving at least radially inwardly toward the rotor (34).

4. The laboratory mill (1) according to any one of the preceding claims, wherein The grinding machine housing (16) has at least one axially extending receiving guide slot (52) for the at least one matching element (36), wherein the receiving guide slot (52) is open radially inwardly toward the rotor (34) and on an axial end side (16a) of the grinding machine housing (16), and the at least one matching element (36) can be axially inserted into the at least one receiving guide slot (52) through the open end side (16a), and wherein an axial linear guide portion (62) is formed between the at least one receiving guide slot (52) and the at least one matching element (36).

5. The laboratory mill (1) according to claim 4, wherein: The at least one receiving guide slot (52) has at least one guide groove (64) extending axially and transversely to the receiving guide slot (52), and the at least one mating element (36) has at least one tongue element (58) movable in the at least one guide groove (64), or vice versa, so that the axial linear guide (62) is constructed as an axially movable tongue and groove guide.

6. The laboratory mill (1) according to claim 5, wherein: The at least one mating element (36) has two flat sides (54a) which extend axially in the at least one receiving guide slot (52) when the at least one mating element (36) is inserted into the at least one receiving guide slot (52), wherein at least one transverse hole (56) passes through the flat sides (54a) of the at least one mating element (36), in which a transverse pin is fixed, which transverse pin is axially movable and radially guided in the at least one guide slot (64) as a tenon element (58).

7. The laboratory mill (1) according to any one of claims 5 to 6, in, The at least one engagement element (36) is supported radially inwardly in the direction of the rotor on a side wall (64a) of the guide groove (64) of the tongue-and-groove guide, and / or wherein the at least one mating element (36) is supported radially outwardly in a direction away from the rotor (34) on a side wall (64b) of the guide groove (64) of the tongue-and-groove guide portion, or wherein a longitudinal side (54b) of the at least one mating element (36) facing away from the rotor (34) is supported directly or indirectly on a radially outer bottom of the receiving guide slot (52).

8. The laboratory mill (1) according to any one of claims 4 to 7, wherein The receiving guide slot (52) has an axial hole (70) on a bottom portion located radially outside, into which an axially extending support pin (72) is inserted, wherein a longitudinal side (54b) of the at least one mating element (36) facing away from the rotor (34) is supported on the support pin (72), and wherein the support pin (72) is supported on the grinding machine housing (16) in the axial hole (70).

9. The laboratory mill (1) according to any one of the preceding claims, wherein The at least one mating element (36) has at least one pulling opening (60) so that a pulling tool can be introduced into the pulling opening (60) in a form-fitting manner so that when the grinding machine housing door (18) is opened, the at least one mating element (36) can be pulled axially out of the grinding machine housing (16) with the help of the pulling tool.

10. The laboratory mill (1) according to any one of the preceding claims, wherein The at least one engagement element (36) has a base body (54) in the form of an elongated plate or strip.

11. The laboratory mill (1) according to claim 10, wherein: The length of the base (54) is between 20 mm and 200 mm, the width of the base (54) is between 8 mm and 60 mm, and / or the thickness of the base (54) is between 3 mm and 25 mm.

12. The laboratory mill (1) according to claim 1, wherein the at least one mating element (36) has at least one flat side (54a) and at least one longitudinal side (54b), which meet at a longitudinal edge (54d), wherein: The longitudinal edge (54d) forms a cutting edge or impact edge of the at least one engaging element (36), which cooperates with a cutting edge or impact edge of the rotor (34) in order to comminute the grinding material therebetween.

13. The laboratory mill (1) according to claim 12, wherein: When the at least one engagement element (36) is inserted into the at least one receiving guide slot (52) of the grinding machine housing (16), the at least one longitudinal edge (54d) extends axially in the grinding chamber (32).

14. Laboratory mill (1) according to any one of the preceding claims, in, The at least one mating element (36) has a base body (54) in the form of an elongated plate or strip, which has two flat sides (54a), two longitudinal sides (54b) extending axially and transversely to the flat sides (54a) and / or two end sides (54c) extending transversely to the flat sides (54a) and the longitudinal sides (54b), and The at least one mating element (36) is particularly designed to be able to be tilted 180° relative to at least one, two or three of the following axes: about an axis extending transversely to said flat side (54a), about an axis extending transversely to the longitudinal side (54b), and / or about an axis extending transversely to the end side (54c), The at least one mating element (36) can thereby be inserted into the grinding machine housing (16) in a first orientation and in a second orientation flipped relative to the first orientation, and / or in a third orientation flipped relative to the first orientation and the second orientation, and / or in a fourth orientation flipped relative to the first orientation, the second orientation and the third orientation, so that the first and second and / or third and / or fourth longitudinal edges (54d) of the at least one mating element (36) can be used as cutting edges or impact edges.

15. The laboratory mill (1) according to any one of claims 4 to 14, wherein The at least one mating element (36) has two flat sides (54a) which extend axially in the at least one receiving guide slot (52) when the at least one mating element (36) is inserted into the at least one receiving guide slot (52), wherein at least four transverse holes (56) are arranged through the flat sides (54a) of the at least one mating element (36), wherein a through transverse pin which protrudes toward both sides as a tenon element (58) is respectively fixed in each of the two axially inner transverse holes (56), and wherein the two axially outer transverse holes (56) form a pulling opening (60).

16. The laboratory mill (1) according to any one of claims 4 to 15, wherein An elastic pressing element is fixed to the grinding machine housing door (18), and when the grinding machine housing door (18) is closed, the elastic pressing element axially presses the axial end side (54c) of the at least one matching element (36) against the axial motor-side end of the receiving guide slot (52).

17. The laboratory mill (1) according to any one of claims 4 to 16, wherein It comprises an annular seal (74) which is fixed to the grinder housing door (18) and seals relative to the axial end side (16a) of the grinder housing and thereby seals the grinding chamber (32) in an annular manner, and wherein, when the grinder housing door (18) is closed, the annular seal (74) axially presses the axial end side (54c) of at least one mating element (36) against the axial motor-side end of the receiving guide slot.

18. The laboratory mill (1) according to any one of the preceding claims, wherein The grinding chamber (32) is formed as a substantially cylindrical cavity in the grinding machine housing (16) and transitions radially downwards into a grinding material outlet channel (82), wherein the grinding chamber (32) and the grinding material outlet channel (82) are separated by a screen plate (42), through which comminuted grinding material can flow downwards from the grinding chamber (32) into the grinding material outlet channel (82) and into a grinding material collecting container (44), wherein the screen plate (42) and the rotor (34) are located in a grinding machine housing door (18). When opened, it can be removed axially from the grinding machine housing (16), and the grinding machine housing (16) does not have a web on its end side (16a) in the area below the screen plate (42) that crosses the grinding material outlet channel (82) laterally, so that when the grinding machine housing door (18) is opened and the rotor (34) and the screen plate (42) are removed, the grinding chamber (32) and the grinding material outlet channel (82) can be cleaned together from the end side (16a) of the grinding machine housing (16) without hindrance.

19. A laboratory mill (1) for comminuting mill material, in particular in the form of a cutting mill or an impact cross mill, in particular according to any of the preceding claims, comprising An apparatus housing (12) having a grinding machine housing (16), wherein: The grinding machine housing (16) defines a grinding chamber (32) and has an axial end side (16a). A rotor grinder (30) is located in the grinding chamber (32) of the grinder housing (16), wherein the rotor grinder (30) includes a rotor (34) and at least one mating element (36), wherein the rotor (34) defines a rotor axis (X), wherein when the rotor (34) rotates, a grinding material is comminuted between the rotor (34) and the at least one mating element (36), A grinding machine drive (2, 4) for driving a rotor (34) in a grinding chamber (32), a grinding machine housing door (18) for closing the grinding machine housing (16) at an axial end side (16a), wherein a grinding chamber (32) is formed in the grinding machine housing (16) in the form of a substantially cylindrical cavity and transitions downwardly into a grinding material outlet channel (82), wherein the grinding chamber (32) and the grinding material outlet channel (82) are separated by a screen plate (42), and comminuted grinding material can flow downwardly from the grinding chamber (32) into the grinding material outlet channel (82) and the grinding material collecting container (44) through the screen plate, and At least one or more protruding conical pins (80) are fixed to the grinding machine housing door (18), which are swung under the screen plate (42) when the grinding machine housing door (18) is closed and support the screen plate downward when the grinding machine housing door (18) is closed.

20. A laboratory mill assembly having a laboratory mill (1) according to any one of the preceding claims and at least two, preferably at least three rotors (34) with predefined different diameters, wherein: The width of the grinding gap between a rotor (34) inserted into a grinding chamber (32) and at least one mating element (36) is selected not by radially adjusting at least one mating element (36), but by replacing the rotor (34) with another rotor (34) having a different diameter.

21. A laboratory mill assembly, comprising a laboratory mill (1) according to any one of the preceding claims and at least two groups, preferably at least three groups, of mating elements (36) of different widths, wherein: The width of the grinding gap between the mating element (36) inserted into the grinding machine housing (16) and the rotor (34) is selected not by radially adjusting the mating element (36), but by replacing the mating element (36) with another mating element (36) having a different width.

Images