Laboratory mill

Abstract

The invention relates to a laboratory mill (1) for comminuting grinding stock, in particular configured as a cutting mill, impact cross mill, disc mill, knife mill or punch mill, comprising a device housing (12), a mill housing (16) and / or a grinding container (17), a grinding chamber (82) which is located in the mill housing (16) or the grinding container (17), wherein a mill (84) can be arranged in the grinding chamber (82) for comminuting the grinding stock, and wherein the mill housing (16) or the grinding container (17) has a user access opening (94), a mill housing door (18) or a safety cover (19) for closing the user access opening (94), wherein the mill housing door (18) or the safety cover (19) has an open state and a closed state, wherein a user can access the mill (84) through the user access opening (94) in the open state of the mill housing door (18) or the safety cover (19) for driving a mill drive (2, 4) of the mill (84), wherein the mill housing door (18) or the safety cover (19) has a closure element (22) with which the mill housing door (18) or the safety cover (19) can be locked in the closed state, and wherein the laboratory mill (1) has a mechanical mill drive locking device (74).

Description

Technical Field

[0001] This invention relates to a laboratory grinder, particularly a laboratory-scale cutting grinder, impact cross grinder, disc grinder, knife grinder, or stamping grinder, which has a grinding machine in which the grinding material is pulverized, for example, in the gap between the grinding machine rotor and one or more fixed corresponding elements, between two discs, or by a rotor cutter or impact rotor. Background Technology

[0002] A cutting and grinding machine pulverizes materials according to the shearing principle between a rotating cutting rotor and one or more fixed, paired cutting elements extending substantially along the axis. The cutting rotor has one or more rotor cutting elements also extending substantially along the axis. This type of laboratory cutting and grinding machine is particularly suitable for pulverizing viscous or fibrous samples, such as biological samples like straw or, for example, plastic films, to name a few. Examples of current laboratory cutting and grinding machines include, for example, the applicant's PULVERISETTE® 19 and PULVERISETTE® 15, the basic structure of which is described herein. Product specifications for the PULVERISETTE® 19 and PULVERISETTE® 15 can be found, for example, at www.fritsch.de.

[0003] In these laboratory-scale cutting and grinding mills, loose material that is more or less flowable is typically injected into the grinding chamber, for example, through a feeding funnel, where a cutting rotor rotates about a horizontal axis. The cutting rotor can have different geometries, such as having straight cutting edges or so-called V-shaped cutting edges. The latter has vortexes and thus achieves good cutting action, especially when pulverizing viscoelastic materials and films.

[0004] Typically, for example, the sieve of a sieve box is located below the cutting rotor, through which the sample material, which has been sufficiently and intensely pulverized, can flow so that it can be collected in a collection container located below it.

[0005] Other structural details of the cutting and grinding machine that are known in principle to those skilled in the art can be found in the product descriptions of the applicant's PULVERISETTE® 19 and PULVERISETTE® 15 cutting and grinding machines, which were available for download at www.fritsch.de at the time of application and publication, and the basic structure of such cutting and grinding machines is incorporated herein by reference. Furthermore, applications DE 196 01 594, DE 10 2018 113 751 A1, WO 2020 / 200759 A1 and DE10 2019 133 437 A1 describe such cutting and grinding machines and are also incorporated herein by reference.

[0006] Potential risks of injury to users of cutting and grinding machines may lie in the grinding chamber located between the rotating cutting rotor and the fixed mating cutting parts or blades. Similar potential risks may also arise in impact cross grinders (see PULVERISETTE® 16, www.fritsch.de) or disc grinders (see PULVERISETTE® 13, www.fritsch.de), the product descriptions of which are incorporated herein by reference. These laboratory grinders also include rotor grinders, in which grinding materials are pulverized between a grinding rotor and fixed corresponding elements of the rotor grinder. Similar potential risks exist in blade grinders or in stamping grinders, sometimes also called high-speed rotor grinders, where the rotor blades rotate about a vertical axis in a grinding container (see PULVERISETTE® 11, www.fritsch.de), and in stamping grinders, where the impact rotor rotates about a vertical axis in a grinding container designed as a collection container within an annular screen (see PULVERISETTE® 14, www.fritsch.de), the product descriptions of which are also incorporated herein by reference.

[0007] In such grinding machines, it is essential to reliably prevent the user from touching the grinding machine, especially the grinding machine rotor or the area between the grinding machine rotor and the fixed corresponding components, during the grinding process, and it is also essential to reliably prevent the grinding machine rotor from starting when the grinding machine is turned on, for example, in the event of a software malfunction.

[0008] Referring again to the example of a cutting and grinding machine, the grinding chamber is typically enclosed by a door on the end face. The door may be electronically monitored and locked to protect the user. Such a grinder may, for example, have an electrical locking device to prevent the door from being opened during operation. Knife-type grinders typically have a correspondingly fixed cover, such as an equipment hood, which, when closed, prevents access to the interior of the grinding container where the rotor blades are arranged.

[0009] For such electrical or electronic safety systems, due to safety requirements, dual-channel or redundant circuitry and various redundant shutdown monitoring are needed to avoid residual risks in the event of electrical failures.

[0010] Grinding machines can also have motor brakes, which can be flanged to the back of the motor shaft to allow for faster braking. For safety reasons, the motor brake operates without current, and the brake shoes are actively disengaged from the motor shaft by energizing the machine to resume operation. However, motor brakes are subject to high wear and typically do not provide monitoring of their proper functioning. Furthermore, such motor brakes require continuous electrical energy during operation to maintain disengagement. Additionally, brakes are generally not safety-guided components in the sense of DIN EN ISO 12100, thus requiring additional electrical safety measures.

[0011] A crushing device is known from DE 27 10 513 A1 of 1977, which has a rotor assembly with blades that works in conjunction with a fixed blade assembly to crush materials. The crushing device has a flywheel and a braking device with brake shoes that act on the inner circumferential surface of the outer edge section of the flywheel to stop its rotation.

[0012] DIN EN ISO 12100 – “Machine Safety” contains general design guidelines for machines, as well as for risk assessment and risk reduction, and is also important for CE certification of laboratory equipment. According to DIN EN ISO 12100, the term “machine safety” refers to the ability of a machine to perform its intended function throughout its entire lifespan without incurring unacceptably high risks.

[0013] To meet the safety requirements of DIN EN ISO 12100, for example, cutting and grinding machines typically have several electrically safe guiding components, such as:

[0014] 1. Safe door contacts,

[0015] 2. Secure door locking device,

[0016] 3. The door locking device provides reliable feedback to the control device of the cutting and grinding machine.

[0017] 4. For diverse and redundant safe shutdown identification of the drive unit,

[0018] 5. Safe torque cutoff of the drive unit.

[0019] 6. Reliable status feedback from each safety circuit and signaling device to the control unit of the cutting and grinding machine.

[0020] The term "safety" is understood according to the meaning of DIN EN ISO 12100.

[0021] While laboratory grinders equipped with electrical or electronic safety devices or motor brakes are validated in principle, they can be costly and require further improvement in terms of potential error-proneness. Summary of the Invention

[0022] The purpose of this invention is to provide a laboratory grinding machine that meets high safety standards, especially in the case of user-assisted grinding.

[0023] Another objective of this invention is to provide a laboratory grinder that is simple, inexpensive, and not prone to malfunction.

[0024] Another aspect of the present invention is to provide a laboratory grinder having a cost-effective and reliable safety device to prevent unintentional user intervention in the grinder. This safety device is compact and can be integrated into a simple and small laboratory grinder.

[0025] Another aspect of the present invention is to provide a laboratory grinder that is particularly safe in the sense of DIN EN ISO 12100, which avoids or at least reduces the aforementioned disadvantages.

[0026] The object of this invention is achieved by the subject matter of the independent claims. Advantageous improvements of the invention are defined in the dependent claims.

[0027] A laboratory grinder for pulverizing abrasive materials is provided, comprising an equipment housing with a grinding machine housing and / or a grinding container. The grinding machine housing or grinding container defines a grinding chamber within the grinding machine housing or grinding container, particularly a rotating grinding machine arranged or installed therein, which is used to pulverize abrasive materials when the grinding machine is in operation. The grinding machine housing or grinding container has a user access opening, particularly axial, through which a user accesses the grinding machine in an open state.

[0028] The user access opening can be closed by the grinding machine housing door or safety cover, thereby defining the open and closed states. When the grinding machine housing door or safety cover is open, the user can access the grinding machine through the user access opening, and when the grinding machine is closed, it is sealed in an anti-access manner to operate the laboratory grinding machine, so that the user can safely not access the grinding machine during operation.

[0029] The grinding machine is particularly constructed as a rotor grinding machine. Laboratory grinding machines also have a motor-driven grinding device for the rotary drive of the grinding machine, for example, via an electric motor and drive shaft.

[0030] The grinding machine housing door or safety cover has a closing element that mechanically locks the grinding machine housing door or safety cover in the closed position so that the laboratory grinder can operate safely.

[0031] Laboratory grinders advantageously feature a mechanical grinding drive locking device, which allows for the mechanical locking of the grinding drive. This device is typically operated mechanically, directly or indirectly, by a locking element.

[0032] Laboratory grinders can be configured as cutting grinders, impact cross grinders, disc grinders, knife grinders, or stamping grinders. In cutting grinders, impact cross grinders, or disc grinders, preferably, a solid grinding machine housing exists around the rotor grinder, and the grinding machine housing is closed by a grinding machine housing door. In this case, the closing element for the grinding machine housing door may also be referred to as a door closure. Knife grinders or stamping grinders may have a grinding container, for example, made of (transparent) plastic or stainless steel, in which a grinding machine rotor, for example, a rotor cutter or an impact rotor, is arranged to rotate about a vertical axis. Knife grinders and stamping grinders may also (but not necessarily) additionally have a enclosure surrounding the grinding container, with a closure. In knife grinders or stamping grinders with an additional enclosure, a safety cover may be configured as a closure, and a closing element may be mounted on the safety cover configured as a closure and lock it in the closed state. In blade grinders or stamping grinders that do not have an additional enclosing enclosure, at least a safety cover is present, which reliably closes the grinding container upwards. In this case, a sealing element may also be installed on the safety cover and locked in the closed position, thereby sealing the grinding container against intrusion.

[0033] When the grinding machine housing door or safety cover is not locked, the grinding machine drive locking device mechanically and form-fits into the grinding machine drive, and releases the grinding machine drive when the grinding machine housing door or safety cover is locked. When the grinding machine housing door or safety cover is closed, the closing element and the grinding machine drive locking device can be interconnected via a mechanical operating chain. On the other hand, when the grinding machine housing door or safety cover is opened, the mechanical operating chain can be interrupted. In other words, through the closed mechanical operating chain, the movement of the closing element can be mechanically transmitted to the grinding machine drive locking device when unlocking and locking the grinding machine housing door or safety cover, thereby locking or unlocking the grinding machine drive locking device.

[0034] Laboratory grinders can be constructed, for example, as laboratory-scale cutting grinders, impact cross grinders, disc grinders, knife grinders, or stamping grinders. In cutting grinders or impact cross grinders, the grinder has one or more fixed cutting elements and a coaxial cutting rotor that rotates within the fixed cutting elements, preferably about a horizontal axis. Cutting grinders operate on the principle of shearing, where the abrasive material is pulverized by cutting between the cutting elements of the cutting rotor and the mating cutting elements. Impact cross grinders have a similar structure but with a larger gap between the cutting elements and the mating cutting elements. In disc grinders, the rotor grinder has axially opposed rotating discs and fixed discs, and the abrasive material is pulverized in the gap extending laterally between the two discs. In stamping grinders, the impact rotor rotates about a preferably vertical axis, for example, in an annular screen, and pulverizes the abrasive material by the impact of the rotor teeth. The rotor grinder and the annular screen can be arranged in a grinding container, which is in turn inserted into a housing. In a blade grinder, a rotor blade without mating cutting elements rotates about a vertical axis within a grinding container. An additional enclosure surrounding the grinding container is possible, but not mandatory.

[0035] Laboratory grinders are particularly large in size, allowing them to be placed on a laboratory table or on legs on the laboratory floor in a typical laboratory setting.

[0036] The axial user access opening is preferably used to allow the user to axially access the grinding chamber when the grinding machine housing door or cover is open, for example, to remove grinding material or the grinding machine rotor from the grinding chamber, or to clean the grinding chamber, or to replace or clean the sieve. For this purpose, the grinding machine rotor is preferably insertable into the drive shaft using a form-fitting element and can be axially tightened or locked if necessary, and can be manually pulled out after the tightening or locking is released if necessary.

[0037] For cutting and grinding machines, the diameter and / or length of the rotor of a laboratory grinding (cutting) machine can be, for example, in the range of a few millimeters, such as from 20 mm to about 15 cm or a maximum of about 20 cm. In disc grinding machines, the diameter can be larger if necessary, for example from 15 cm to 30 cm.

[0038] To enable the feeding of abrasive material to the grinding machine when the grinding machine housing door or safety cover is closed during operation of the laboratory grinder, the grinding machine housing or safety cover may also have axial or radial feeding ports for abrasive material, such as feeding funnels, through which abrasive material can be axially or radially filled into the grinding chamber for continuous grinding by the grinding machine, for example, between the grinding machine rotor and one or more fixed corresponding elements, or by means of rotor cutters or impact rotors. In cutting grinders, the feeding ports are particularly radial, while in impact cross grinders, disc grinders, blade grinders, or stamping grinders, they are particularly axial.

[0039] Advantageously, a high level of user safety can be ensured by utilizing a mechanical grinding drive locking device that mechanically and form-fits the grinding drive. This reliably prevents, for example, the grinding rotor (e.g., the cutting rotor), rotating disc, rotor tool, or impact rotor from rotating when the grinding housing door or safety cover is open. Furthermore, potential malfunctions of electronic safety devices do not compromise the laboratory grinder's safety against accidental opening of the grinding chamber. In addition, unintentional and even intentional misoperation can be effectively prevented. The form-fitting locking of the mechanical operation of the grinding drive also prevents unauthorized manipulation above average and generally provides a high level of safety against injury-prone misoperation or unforeseen events. In particular, it can at least partially eliminate, for example, multiple redundant electronic safety devices, safety contacts, safety locking devices, or electrical status feedback to the control unit. Nevertheless, the safety requirements of the laboratory equipment in the sense of DIN EN ISO 12100 or for obtaining CE marking can be met.

[0040] A grinding machine drive unit can include a drive motor, particularly an electric motor, and a drive shaft connected to the grinding machine to rotatably drive the grinding machine. When the grinding machine housing door or safety cover is not locked, a mechanical grinding machine drive locking device can act on the drive shaft and mechanically lock the rotation of the drive shaft in a form-fit manner. Here, the grinding machine drive locking device can preferably be located between the drive motor and the grinding machine rotor. The direct form-fit locking of the drive shaft ensures high safety, for example, preventing electrical malfunctions in the grinding machine drive unit.

[0041] According to the present invention, the grinding machine drive locking device of the machine has a form-fitting, especially axially form-fitting, coupling member that releases the grinding machine drive for rotation in a disengaged state and form-fittingly locks the grinding machine drive in an engaged state.

[0042] The axially shaped coupling has a stator coupling portion connected to the equipment housing and a rotor coupling portion connected to the grinding machine drive and / or the rotating components of the grinding machine. In the shaped-fit engagement state of the stator coupling portion and the rotor coupling portion, the coupling locks the rotation of the grinding machine drive and / or the grinding machine in a shaped-fit manner.

[0043] Preferably, the form-fitting coupling is directly or indirectly operated by a closing element, for example, by a mechanical control chain. Here, for example in a rotatable closing element, the rotational movement of the closing element can be converted into a movement that mechanically causes the engagement and disengagement of the form-fitting coupling.

[0044] The engagement and disengagement of form-fitting couplings can be achieved, for example, by axial movement of the stator coupling and / or rotor coupling. The stator and rotor couplings can have complementary teeth that mesh with each other, particularly axially, when the form-fitting couplings engage, so as to form-fittically lock the rotation of the grinding machine. These teeth can preferably taper towards the other complementary coupling to facilitate engagement. This largely prevents engagement from being impossible in tooth-to-tooth positions.

[0045] When the closing element moves to open, the grinding machine drive locking device is locked first, or the form-fitting coupling is engaged first. Only after the grinding machine drive locking device is locked, or the form-fitting coupling is engaged and the grinding machine drive is locked in a form-fitting manner, can the closing element continue to open mechanically until the grinding machine housing door or safety cover is unlocked. In other words, as long as the grinding machine drive locking device is not locked or the form-fitting coupling is not engaged, the unlocking of the grinding machine housing door or safety cover is mechanically locked, and the grinding machine housing door or safety cover cannot be unlocked. When the closing element moves to close, the grinding machine housing door or safety cover is locked first, and only after the grinding machine housing door or safety cover is locked, as the closing element further closes, is the grinding machine drive locking device unlocked, or the form-fitting coupling is disengaged, and the grinding machine drive is released to rotate. Therefore, at least as long as the closing element is not locked, the grinding machine drive locking device cannot be mechanically unlocked or the form-fitting coupling cannot be disengaged. Therefore, the opening of the closing element occurs in two phases of its movement. In the first phase, the closing element first engages the grinding machine drive locking device via a mechanical control chain, and then in the second phase, the closing element unlocks the grinding machine housing door or safety cover. Similarly, the closing of the closing element also occurs in two phases of its movement. In the first phase, the closing element first locks the grinding machine housing door or safety cover, and then in the second phase, the closing element unlocks the grinding machine drive locking device via a mechanical control chain.

[0046] Therefore, the movement of the closing element during closing, especially in the time-sequential movement phases, takes place:

[0047] 1. The grinding machine housing door or safety cover is locked by a closing motion, such as rotation of the closing element in the closing direction, wherein the grinding machine drive locking device remains locked.

[0048] 2. The grinding machine drive locking device is unlocked during a continuous closing motion, such as the rotation of the closing element in the closing direction, wherein the closing element keeps the grinding machine housing door or safety cover locked.

[0049] The movement of the closing element during opening occurs, especially in the temporally sequential phases of the movement:

[0050] 1. The grinding machine drive locking device is locked by opening a movement, such as rotating a closing element, wherein the closing element keeps the grinding machine housing door or safety cover locked.

[0051] 2. The grinding machine housing door or safety cover is unlocked during a continuous opening motion, such as the rotation of a closing element, wherein the grinding machine drive locking device remains locked.

[0052] In other words, a laboratory grinder has the following four states:

[0053] 1. The grinding machine housing door or safety cover is open, and the grinding machine drive locking device is locked, allowing the user to safely access the grinding machine.

[0054] 2. The grinding machine housing door or safety cover is closed but not locked, while the grinding machine drive locking device is locked.

[0055] 3. The grinding machine housing door or safety cover is closed and locked, but the sealing element has not yet moved to the stop, in which the grinding machine drive locking device is locked.

[0056] 4. The grinding machine housing door or safety cover is closed and locked, and the sealing element moves to the stop, wherein the grinding machine drive locking device is unlocked.

[0057] To put the machine into operation, the user operates the laboratory grinder as follows, starting from the open position of the grinder housing or safety cover and the locked position of the grinder drive locking device:

[0058] 1. The user closes the grinding machine housing door or safety cover, in which the grinding machine drive locking device is locked.

[0059] 2. The user moves the closing element in the closing direction and thereby locks the grinding machine housing door or safety cover first, while the grinding machine drive locking device remains locked.

[0060] 3. The user continues to move the closing element in the closing direction to the stop, thereby operating the grinding machine drive locking device to unlock.

[0061] To open the machine, the user operates the laboratory grinder from the closed position of the grinder housing or safety cover and the unlocked position of the grinder drive locking device as follows:

[0062] 1. The user moves the closing element from the stop in the opening direction, thereby first operating the grinding machine to drive the locking device to lock it.

[0063] 2. The user continues to move the closing element in the opening direction, thereby unlocking the grinding machine housing door or safety cover, while the previously locked grinding machine drive locking device remains locked.

[0064] 3. The user opens the grinding machine housing door or safety cover to access the grinding machine, where the grinding machine drive locking device remains locked.

[0065] This ensures that the grinding machine drive is reliably mechanically locked the moment the grinding machine housing door or safety cover is unlocked, and thus reliably locked before the grinding machine housing door or safety cover can be opened, preventing any further inertial rotation. Furthermore, with the grinding machine housing door or safety cover open, for example in the event of an electronic malfunction, startup can be reliably prevented, ensuring a high standard of safety.

[0066] Preferably, the form-fit coupling has a stator coupling ring and a rotor coupling ring disposed around the drive shaft. The stator coupling ring can be fixed to the equipment housing in a rotationally resistant manner, allowing a substantially angular clearance, and the drive shaft can rotate within the stator coupling ring. The rotor coupling ring can be fixed to the drive shaft in a substantially rotationally resistant manner.

[0067] The form-fitting couplings are preferably capable of engaging at any rotational position of the grinding machine rotor, especially without starting the drive motor. This can be achieved, for example, by having at least one of the form-fitting coupling portions have at least such a large clearance relative to the other coupling portion that the couplings can engage in a form-fitting manner, for example, the teeth of the couplings can engage in a form-fitting manner, even when the grinding machine rotor is jammed, for example, by the material being ground. Preferably, there is a clearance on both sides, so that the couplings can be fully engaged at any rotational position of the grinding machine rotor and the grinding machine housing door can be opened. For this purpose, for example, in axially form-fitting couplings, it is advantageous that the couplings have multiple teeth, and / or that at least one of the axially form-fitting couplings or two coupling rings has a slight angular clearance in both rotational directions, i.e., at least such a large angular clearance that the coupling teeth can still be fully engaged at any rotational position of the grinding machine rotor even when it is completely jammed. The clearances or angular clearances on both sides are preferably balanced in the middle when the couplings are in the separated state.

[0068] By axially moving the stator coupling ring and / or the rotor coupling ring, the form-fitting coupling elements can engage and disengage to lock and release the grinding machine drive locking device.

[0069] According to one exemplary embodiment, the form-fitting coupling member may have an axial pressure plate that is manipulated to move axially by the movement of the closing element when the closing element moves in the opening direction, so as to form-fit the stator coupling ring and the rotor coupling ring with each other.

[0070] As part of a mechanical control chain, a mechanical control device may be included. When the grinding machine housing door or safety cover is closed, a closing element is coupled to the mechanical control device, and the mechanical control device mechanically transmits the movement of the closing element to a grinding machine drive locking device when locking and unlocking the grinding machine housing door or safety cover. The mechanical control device can thus form a mechanical connection between the closing element and the grinding machine drive locking device in the mechanical control chain, such that the mechanical operation of the grinding machine drive locking device is indirectly performed via the mechanical control device through the closing element.

[0071] According to one embodiment, the mechanical actuation device also allows the stator coupling to have a rotational clearance such that, for example, when the grinding machine gets stuck by the abrasive material inside the grinding machine housing, the teeth of the stator coupling and the rotor coupling can still engage due to the rotational clearance. Alternatively or additionally, the rotor coupling may also have a rotational clearance relative to the drive shaft to such a small extent. This facilitates the engagement of form-fitting couplings while maintaining safety features. As mentioned above, engagement can also be simplified by, for example, teeth with a gradually tapering cross-section of a triangle.

[0072] To enable coupling when the grinding machine housing door or safety cover is closed, the closing element and the mechanical actuation device can have complementary coupling elements that couple with each other when the grinding machine housing door or safety cover is closed and disengage when the grinding machine housing door or safety cover is opened. Thus, in the coupled state, when the grinding machine housing door or safety cover is closed, the movement of the closing element is mechanically transmitted via the coupled coupling elements and the mechanical actuation device to the grinding machine drive locking device, so as to release the grinding machine drive locking device when the closing element is closed and lock the grinding machine drive locking device and the grinding machine drive when the closing element is opened. Shape-fitting axially engaging elements, such as complementary dihedrals or polygons, have proven advantageous as complementary coupling elements when the grinding machine housing door or safety cover is closed. Dihedrals also have the advantage that they can couple only in two orientations rotating 180°.

[0073] The locking element can be configured, for example, as a key with a rotary handle that engages in a locking sleeve on the grinding machine housing, wherein the grinding machine housing door or safety cover is locked in the locking sleeve by rotation of the key. For example, the key may include two transverse locking bolts that engage in complementary locking sleeves and lock in the locking sleeves upon rotation (keylock principle). Advantageously, locking occurs at a small angle of key rotation, and the disengagement of the form-fitting coupling only begins when the key continues to rotate while closing the grinding machine housing door or safety cover; that is, with continuous key rotation, the disengagement of the form-fitting coupling only begins after the key has already locked.

[0074] Therefore, when the grinding machine housing door or safety cover is closed, the key can form a mechanical control chain with the grinding machine drive locking device through the coupled coupling element and mechanical operating device, so that the rotation of the key causes the grinding machine drive locking device to lock and unlock through the coupled, for example, dihedral coupling element and mechanical operating device.

[0075] This allows for a simple, cost-effective, yet reliable locking of the grinding machine housing door or safety cover when used in conjunction with a drive locking device.

[0076] According to one embodiment, the mechanical actuation device may have a lateral sliding element, such as a lateral sliding plate, wherein the actuation, such as rotation of a closing element, causes lateral movement of the sliding plate relative to the drive shaft. Therefore, the mechanical actuation device can be compactly integrated into the drive scheme of a laboratory grinder, and the mechanism for inducing drive locking can still be implemented stably and safely.

[0077] According to one embodiment, the machine's operating mechanism may include an operating shaft and an eccentric wheel. The operating shaft may have one of two complementary coupling elements, such that when the grinding machine housing door or safety cover is closed and / or a closing element or key is inserted into a closing sleeve, the closing element or key (including the other of the two complementary coupling elements) is detachably coupled to the operating shaft. In the coupled state of the complementary coupling elements, the operating shaft can be rotated by rotation of the closing element or key, and the eccentric wheel converts the rotational motion into lateral movement of a sliding plate.

[0078] Furthermore, the mechanical operating device may have at least one wedge element that converts the lateral movement of the sliding plate, for example by a pressure plate of an axially movable, form-fitting coupling member, into the axial movement of the form-fitting coupling member, i.e., the axial movement of the stator coupling portion or stator coupling ring and / or the rotor coupling portion or rotor coupling ring.

[0079] The critical safety of a laboratory grinder can be achieved through a form-fitting mechanical locking of the grinder drive. However, additional electrical or electronic protection measures can be implemented. These could include a control unit and an electrically activated retaining device, such as an electromagnet. When the grinder is running, the control unit activates the retaining device, which magnetically holds the operating mechanism, such as a sliding plate. As long as the grinder drive is rotating, the magnetically attached retaining device prevents movement of the locking element. The control unit can query the rotation of the grinder drive or wait for a predetermined idling delay time, and only deactivates the retaining device when it detects that the grinder drive has stopped rotating or the idling delay time has ended. This prevents the user from attempting to unlock the locking element while the coupling parts are still rotating relative to each other, thus preventing engagement of the form-fitting coupling. While the locking element cannot be completely unlocked mechanically via a mechanical operating chain as long as the form-fitting coupling is not engaged, the retaining device prevents undesirable wear on the form-fitting coupling caused by misoperation. However, this does not necessarily necessitate the design of this additional electronic control protection function with safety redundancy, but it should not be excluded.

[0080] When the closing element is opened, its movement is mechanically and rigidly coupled or forcibly guided to the grinding machine drive locking device via a mechanical actuation mechanism, so as to reliably lock the grinding machine drive locking device by engaging the form-fitting coupling. Similarly, when the closing element is closed, its movement is transmitted to the grinding machine drive locking device via a mechanical actuation mechanism, unlocking the grinding machine drive locking device and releasing the form-fitting coupling for separation. The separation of the form-fitting coupling can be caused by one or more spring elements. That is, the engagement of the form-fitting coupling can overcome the spring tension. However, forced-guided separation is not excluded.

[0081] According to one aspect of the present invention, a laboratory grinder is provided, which is in the form of a cutting grinder, an impact cross grinder, or a disc grinder for pulverizing and grinding materials, comprising:

[0082] Equipment housing with grinding machine housing,

[0083] A grinding chamber is provided in the grinding machine housing, in which a grinding machine is arranged to pulverize and grind materials, and the grinding machine housing has a user access opening.

[0084] A grinding machine housing door for closing the user access opening, wherein the grinding machine housing door has open and closed states, and wherein a user can access the grinding machine through the user access opening when the grinding machine housing door is open.

[0085] Grinding machine drive unit used to drive grinding machines

[0086] The grinding machine housing door is equipped with a lock, which can be used to lock the grinding machine housing door in the closed state, and

[0087] The laboratory grinder has a mechanical grinding drive locking device.

[0088] According to another aspect of the invention, a laboratory grinder in the form of a blade grinder or a stamping grinder for pulverizing and grinding materials is provided, comprising:

[0089] Equipment housing and grinding container,

[0090] The grinding chamber in the grinding container, wherein a rotor grinding machine having a grinding rotor (e.g., a rotary cutter or impact rotor) rotating, particularly about a vertical axis, can be arranged in the grinding chamber to pulverize and grind materials, and

[0091] The grinding container has, in particular, a user access opening at the top of the grinding container that opens upwards.

[0092] A safety cover, wherein the safety cover has an open state and a closed state, wherein the safety cover in the open state allows the user to access the grinding machine rotor by means of the user access opening, particularly from above;

[0093] Grinding machine drive unit used to drive the rotor of a grinding machine

[0094] The safety cover has a closure element that allows it to be locked in the closed state.

[0095] The laboratory grinder has a mechanical grinding drive locking device. Attached Figure Description

[0096] The present invention will now be described in detail with reference to embodiments and accompanying drawings, wherein the same and similar elements partially have the same reference numerals, and features of different embodiments can be combined with each other. Wherein:

[0097] Figure 1 A three-dimensional view of a cutting and grinding machine according to an embodiment of the present invention is shown.

[0098] Figure 2 It shows Figure 1 A cutting and grinding machine with a transparent grinding housing.

[0099] Figure 3 It shows Figure 1 A cutting and grinding machine with an openable grinding machine housing door.

[0100] Figure 4 It shows the slightly open state. Figure 1 A partially transparent 3D view of the grinding machine housing door and door lock of a cutting and grinding machine.

[0101] Figure 5 It shows the slightly open state. Figure 1 A partially transparent three-dimensional view of the grinding machine housing from the motor side.

[0102] Figure 6 The image shows the state when the device is off. Figure 1 A partially transparent 3D view of the grinding machine housing of a cutting and grinding machine.

[0103] Figure 7 A partially transparent three-dimensional view of the operating mechanism is shown in the engaged state of the form-fitting coupling and in the state where the grinding machine housing door is closed but unlocked.

[0104] Figure 8 It shows Figure 7 A magnified view of region A in the image.

[0105] Figure 9It shows Figure 7 A magnified view of region B in the image.

[0106] Figure 10 A three-dimensional view of the actuating device and the form-fitting coupling in the engaged state is shown.

[0107] Figure 11 This shows a rearward axial view of the operating device in the engaged state of the form-fitting coupling.

[0108] Figure 12 A partially transparent three-dimensional view of the operating mechanism is shown with the grinding machine housing door closed and locked, and in the disengaged state of the form-fitting coupling.

[0109] Figure 13 It shows Figure 12 A magnified view of region A in the image.

[0110] Figure 14 It shows Figure 12 A magnified view of region B in the image.

[0111] Figure 15 A three-dimensional view of the control device and the shape-fitting coupling element in the disassembled state is shown.

[0112] Figure 16 This shows a rearward axial view of the operating device in the disengaged state of the form-fitting coupling.

[0113] Figure 17 It shows Figure 1 The longitudinal section of the cutting and grinding machine.

[0114] Figure 18 A three-dimensional view of a knife grinder with a partially open safety cover according to another embodiment of the present invention is shown.

[0115] Figure 19 It shows Figure 18 A magnified view of region A in the image.

[0116] Figure 20 like Figure 19 However, the safety cover was almost closed.

[0117] Figure 21 It shows Figure 18 A partially cutaway 3D view of a knife grinder with a closed safety cover.

[0118] Figure 22 It shows Figure 21 A magnified view of region A in the image.

[0119] Figure 23A three-dimensional view of a knife grinder with a partially open safety cover according to another embodiment of the present invention is shown.

[0120] Figure 24 It shows Figure 23 A magnified view of region A in the image.

[0121] Figure 25 like Figure 23 However, the safety cover was closed.

[0122] Figure 26 It shows Figure 25 A magnified view of region A in the image.

[0123] Figure 27 like Figure 25 However, the components were hidden.

[0124] Figure 28 It shows Figure 27 A magnified view of region A in the image.

[0125] Figure 29 It shows Figure 1 A partially transparent rearward 3D view of the cutting and grinding machine. Detailed Implementation

[0126] Reference Figure 1-17 Figures 29 and 29 show a laboratory grinder 1, in this example, in the form of a cutting grinder. The laboratory grinder 1 has a housing 12 with a user display 14 for inputting grinding parameters into the control unit (not shown) of the laboratory grinder 1 by the user. A grinding machine housing 16 is arranged on the front 12a of the housing 12, which can be closed in the front (axial direction) using a safety cover in the form of a grinding machine housing door 18. The grinding machine housing door 18 is constructed as a swing door and can be opened and closed by swinging about a hinge 20. When the grinding machine housing door 18 is... Figure 1 When closed, the grinding machine housing door 18 can be locked using a closing element 22 in the form of a door lock 22'. Only when the closing element 22 is fully unlocked can the user pivot the grinding machine housing door 18 to access the rotor grinder 84 within the inner cavity or grinding chamber 82 of the grinding machine housing 16. With the grinding machine housing 16 closed, abrasive material can be injected through the feeding funnel 24 and, in this example, the radial abrasive material feeding port 25, thereby enabling continuous feeding and pulverization of the abrasive material during operation of the cutting and grinding machine.

[0127] The closure element 22 includes, for example, a rotary handle 23 or knob and a locking bolt 26 to form a key 28. The closure element 22 or key 28 is rotatably arranged in the grinding machine door 18 and can be inserted into a closure sleeve 30 on the front side 16a of the grinding machine housing 16 in a suitable rotational position. Through the lateral extension of the locking bolt 26, the key 28 is engaged only when the closure element 22 is in the... Figure 3-4 When the locking element 22 is in the unlocked rotating position shown, it can be inserted into the locking sleeve 30. In this example, the locking sleeve 30 is formed as a keyhole, and when the locking bolt or transverse bolt 26 is vertical, the locking element 22 or the key 28 can engage in the locking sleeve 30. The locking sleeve 30 has a transverse groove 31 according to the type of keyhole, and when the key 28 is inserted into the locking sleeve 30, the locking bolt or transverse bolt 26 is inserted into the groove according to the key-keyhole principle. By then turning the locking element 22 with the transverse bolt 26 out from the vertical direction, the transverse bolt 26 is locked in the locking sleeve 30 and thus the grinding machine housing door 18 is locked.

[0128] The closure element 22 has a form-fitting coupling element 34 on its coupling end 32. When the coupling end 32 is inserted into the closure sleeve 30, a form-fitting connection is formed between the coupling element 34 and the complementary coupling element 36 of the operating shaft 38, so as to establish a form-fitting connection between the closure element 22 and the operating shaft 38. In this embodiment, the operating shaft 38 is rotatably supported in the closure sleeve 30, and the two complementary form-fitting coupling elements 34, 36 are respectively configured in the form of complementary dihedrals 35, 37. When the grinding machine housing door 18 is closed and the closure element 22 is inserted into the closure sleeve 30, the two dihedrals 35, 37 engage with each other in a form-fitting manner. When the closure element 22 is subsequently rotated to lock in the closure sleeve 30 with the grinding machine housing door 18 closed, the closure element 22 causes the operating shaft 38 to rotate through the coupling of the two dihedrals 35, 37. At the end 38b of the control shaft 38 opposite to the coupling element 36, the eccentric disk 40 is fixed in a defined angular position, for example, tightened in a defined angular position in a manner that the control shaft 38 and the eccentric disk 40 are mutually shaped and fitted.

[0129] The closing element 22, the closing sleeve 30, and the coupling elements 34 and 36 are explicitly rotated relative to each other by means of the engagement of the coupling elements 34 and 36 when the operating chain 65 is closed. In this example, two rotational positions of the closing element 22 are possible. In other words, the transverse groove 31 is oriented such that in the same rotational position of the closing element 22, the two coupling elements 34 and 36 are also axially engaged with each other, in which the locking bolt 26 of the closing element 22 is inserted into the transverse groove 31. Furthermore, the closing element 22 can only be locked when it has been introduced into the closing sleeve 30 to the extent that the two coupling elements 34 and 36 are coupled with each other or the operating chain 65 is closed.

[0130] refer to Figure 5-16 An eccentric disk 40 is guided within the opening 42 of a transverse sliding plate 44. When the closing element 22 is manually rotated by the user, it transmits the rotational motion of the closing element 22 to the operating shaft 38 via coupling elements 34 and 36. The operating shaft 38 then causes the eccentric disk 40 to rotate within the rectangular opening 42. The sliding plate 44 is transversely guided by a linear guide 46, such that the sliding plate 44 is moved horizontally in this example, driven by the eccentric disk 40, or more precisely, initially driven by the manual operation of the closing element 22, and in this example by the rotation of the closing element 22. Therefore, through the arrangement of the eccentric disk 40 in the opening 42, the rotational motion of the closing element 22 or the operating shaft 38 is converted into a transverse translational motion of the sliding plate 44. The locking of the closing element 22 or the grinding machine housing door 18 thus simultaneously causes the rotation of the operating shaft 38 and the eccentric wheel 40, and consequently causes the transverse movement of the sliding plate 44.

[0131] A wedge drive 48 with an inclined plane or lifting wedge 50 is arranged on the sliding plate 44. When the sliding plate 44 moves laterally, the cylindrical pin 52 of the pressure plate 54 slides on the lifting wedge 50, thereby converting the linear lateral movement of the sliding plate 44 into axial movement of the pressure plate 54 relative to the rotation axis X of the laboratory grinder. A stator coupling portion 56 in the form of a stator coupling ring 57 is fixed on the pressure plate 54, and moves axially via the pressure plate 54. A rotor coupling portion 58 is arranged in the form of a rotor coupling ring 59 axially opposite to the stator coupling portion 56. The two coupling portions or coupling halves 56, 58 have form-fitting meshing elements 62 and form a form-fitting coupling member 60, the meshing elements being in the form of complementary teeth 68. When the stator coupling portion 56 moves axially relative to the rotor coupling portion 58 by means of the pressure plate 54 and the complementary teeth 68 of the two coupling portions 56, 58 axially form a form fit, the coupling member 60 engages.

[0132] Drive shaft 2 of drive motor 4 Figure 17The rotor coupling ring 59 extends coaxially through the two coupling rings 57 and 59 and defines the drive axis X. Here, the rotor coupling ring 59 is fixed to the drive shaft by means of a form fit, i.e., it rotates with the drive shaft. The stator coupling ring 57 is torsionally fixed to the equipment housing 12 by means of a pressure plate 54 within a cut 64 of the sliding plate 44, allowing a certain angular clearance. When the stator coupling ring 57 moves axially toward the rotor coupling ring 59, a form fit connection is formed, which form fits to lock the drive shaft to prevent rotation. Therefore, the two coupling portions 56 and 58 form the coupling halves of the form fit coupling member 60, which, when the coupling member 60 is engaged, form fits to lock and prevent the rotation of the drive shaft.

[0133] The mechanical operation for engaging the coupling member 60 is correspondingly performed via a mechanical operating chain 65, via the rotation of the closing element 22, and further via an eccentric disk 40 and a wedge drive 48 having a lifting wedge 50 and a pin 52, to engage and disengage the coupling member 60. The closing element 22, when inserted into the closing sleeve 30, is connected to the operating shaft 38 via coupling elements 34, 36. The eccentric disk converts rotational motion into lateral movement of the sliding plate 44. The wedge drive causes linear lateral movement of the sliding plate 44, resulting in linear axial movement of one of the two coupling halves or coupling portions 56, 58 of the form-fitting coupling member 60. In other words, the operating shaft 38, eccentric disk 40, sliding plate 44, wedge drive 48, lifting wedge 50, and pressure plate 54, together with the pin 52, form an example of a mechanical operating device 66, which mechanically transmits the rotational motion of the closing element 22 to the form-fitting coupling member 60 to engage and disengage the coupling member.

[0134] Generally, the rotation of the closing element 22 is converted into axial movement when the closing element is unlocked and locked, by means of which the coupling parts 56, 58 or the coupling member 60 are axially engaged and disengaged.

[0135] In the engaged state of the form-fitting coupling member 60, rotation of the drive shaft is prevented by the fact that the pressure plate 54 is located in the rectangular cutout 64 of the sliding plate 44 and is held therein in a form-fitting manner. However, when the form-fitting coupling member 60 is engaged, the pressure plate 54, in this example, has a small angular clearance around the drive shaft 2 in the cutout 64 by means of an angle 55. Thus, when the form-fitting coupling member 60 is engaged, the mutual meshing of the complementary teeth 68 becomes easier because it prevents the teeth 68 from being opposite each other in a tooth-to-tooth position and thus from failing to engage. Furthermore, the teeth 68 gradually taper towards the corresponding opposite coupling ring to further improve engagement. In this example, the teeth 68 have a triangular cross-section.

[0136] To allow the pressure plate 54 to re-enter the initial position of separation of the form-fitting coupling 60 or unlocking of the drive shaft when the closing element 22 is locked, i.e., when the sliding plate 44 is pulled back, the pressure plate 54 is guided by two spring pressure members 70, whose spring-loaded balls are embedded in tapered holes. The pressure members 70 cause the pressure plate 54 to elastically return to the separated state of the form-fitting coupling 60. Nevertheless, the pressure members 70 allow slight angular torsion about the drive shaft so that the form-fitting coupling 60 can engage even when the grinding rotor 86 is jammed. The spring pressure members 70 ensure that the angular clearance of the pressure plate 54 is centrally balanced in the separated state, thereby providing sufficient angular clearance for the pressure plate 54, or more generally the form-fitting coupling 60, in both rotational directions, so that the form-fitting coupling 60 can engage in any rotational position of the drive shaft, even when the grinding rotor 86 is jammed.

[0137] When the laboratory grinder 1 is running, the sealing element 22 locks, the form-fitting coupling 60 disengages, and the sliding plate 44 is positioned according to... Figure 12-16 In the separated position. With the locking of the sealing element 22 and the unlocking of the grinding machine drive, the sliding plate 44 is magnetically fixed by the electromagnet 72.

[0138] The maximum idling delay time of the drive unit is stored in the control device (not shown) of the laboratory grinder 1, which is typically housed in the equipment housing 12. After waiting for this maximum idling delay time, the control device deactivates a holding device, such as an electromagnet 72, thereby releasing the movement of the mechanical operating chain 65 and unlocking the closing element 22. Waiting for the maximum idling delay time ensures that the drive unit has stopped when the holding device is deactivated. This eliminates the need for technically complex electrical shutdown monitoring of the drive unit. As long as the drive shaft rotates, the control device keeps the electromagnet 72 activated, causing it to hold the sliding plate 44 in place, preventing the user from attempting to open the grinder housing cover 18 while the drive shaft is rotating. Although the unlocking of the closing element 22 from the closing sleeve 30 is mechanically locked as long as the form-fitting coupling 60 is not engaged, magnetic fixation prevents the user from attempting to engage the form-fitting coupling 60 while the machine is rotating. Therefore, undesirable wear due to incorrect operation can be avoided.

[0139] Furthermore, the rotational position of the eccentric wheel 40, and consequently the position of the sliding plate 44 or the mechanical operating device 66, can be queried via an electric motor start-stop device, such as using a sensor or switch 73. However, this switch does not need to be a safety switch, as the mechanical locking of the drive mechanism prevents damage even in the event of switch failure. However, the use of a safety switch is not excluded. The same applies to fixation via the magnetism of the electromagnet 72. The control unit of the laboratory grinder 1 receives a release signal from the electric motor start-stop device, which allows the user to start the drive motor 4. This prevents the user from attempting to start the drive motor 4 while the form-fitting coupling 60 is engaged, as the motor start-stop device has not yet given a release signal and thus also safely disconnects, for example, the inverter of the drive motor 4.

[0140] Reference Figure 29 The motor start-stop device switch 73 can be configured, for example, as a magnetic proximity switch between the eccentric wheel 40 and, for example, the angle plate 75 of the grinding machine housing 16, and detects the position of the machine's operating device 66. A release signal to start the motor 4 is only sent when the grinding machine drive locking device 74 is in the unlocked state.

[0141] Refer again Figure 5-16 The operation and function of the grinding drive locking device 74, which locks the grinding drive unit by means of the form-fitting coupling 60, can be summarized as follows. The user inserts the closing element 22 into the closing sleeve 30 and rotates the closing element 22 in the closing direction. Here, the closing element 22 is locked first, and the form-fitting coupling 60 is only disengaged upon further rotation. This reliably prevents the situation where the closing element 22 is not locked, but the form-fitting coupling 60 is disengaged. Conversely, when opening the closing element 22, the form-fitting coupling 60 is engaged first to lock the grinding drive unit, while the grinding machine housing door 18, i.e., the transverse bolt 26, remains locked in the closing sleeve 30 during this period. Only at the end of the opening rotational movement of the closing element 22, after the form-fitting coupling 60 has engaged, is the locking of the closing element 22 achieved. Figure 8 The image shows the unlocked state, in which the closing element 22 can be pulled out from the closing sleeve 30 to allow the grinding machine housing door 18 to swing open. A 90° circumferential groove 76 with ends 76a, 76b forms a guide for the transverse bolt 26 in the closing sleeve 30. Figure 5-6 The slot 76 also has an adjustment section, by means of which the closing element 22 is adjusted, and thus the grinding machine housing door 18 is adjusted (beigezogen).

[0142] The machine's operating device 66 has stops on both sides for movement of the grinding machine drive locking device 74 in the locked or unlocked state, which are provided in this example by a linear guide 46.

[0143] When the grinding machine housing door 18 is fully swing open, the user can axially access the grinding chamber 82 and the rotor grinding machine 84 disposed therein. The rotor grinding machine has a cutting rotor 86 that rotates coaxially with the drive axis X and a plurality of axially extending, fixed mating cutters 88 arranged around the cutting rotor 86. The cutting rotor 86 is preferably fitted onto the drive shaft and axially tightened and driven by a form-fitting element. When the grinding machine housing cover 18 is fully open, the user can axially remove the cutting rotor 86 from the drive shaft and axially pull it out through the axial user access opening 94. During operation, the cutting rotor 86 rotates and the grinding material is fed to the rotor grinding machine 84 via the loading funnel 24 through the radial grinding material loading port 25, and is pulverized by cutting action between the rotor cutters 90 of the cutting rotor 86 and the fixed mating cutters 88. Subsequently, the pulverized grinding material drips downwards, for example, through a screen 98 into a collection container 99.

[0144] Reference Figure 18-22 The laboratory grinder 1, in the form of a blade grinder, has a grinding container 17, the inner cavity of which defines a grinding chamber 82, and the grinding container is placed vertically on the lower part 12a of a housing 12. A drive motor (not shown here) is housed in the housing 12 and drives a grinding rotor 86 in the form of a rotor blade (not shown) arranged in the grinding chamber 82 of the grinding container 17 via a vertical drive shaft. Such blade grinders are known in principle to those skilled in the art (see PULVERISETTE® 11, www.fritsch.de).

[0145] The space surrounding the grinding container 17 can be closed by a safety cover 19 (in this example, in the form of a swingable safety shield), thereby reliably enclosing the grinding container 17 by the equipment housing 12. The grinding container 17 may also have an inner cover 104, but this inner cover need not fulfill a safety function. When the safety cover 19 is closed, as in a cutting and grinding machine, the closure element 22 engages in the closure sleeve 30, coupled to the mechanical actuation device 66, thus closing the mechanical actuation chain 65 and locking it on the housing, and operating the grinding machine drive locking device 74 via the mechanical actuation chain 65. Furthermore, the mechanical actuation chain 65 and the grinding machine drive locking device 74 are as described in... Figure 1-17 It works as shown in the cutting and grinding machine. To avoid repetition, refer to the description here and incorporate it into this document.

[0146] Reference Figure 23-28The blade grinder can also be used with a safety cover 19, which, while reliably closing the upper opening of the grinding container 17, leaves the periphery of the grinding container 17 unused. The operating device 66 can, for example, be laterally mounted in the tower-shaped housing portion 106. Safety is ensured by the safety cover 19, which, as in… Figure 1-22 As shown in the cutting or blade grinding machine, it works in conjunction with the grinding machine drive locking device 74. Furthermore, the mechanical control chain 65 and the grinding machine drive locking device 74, as in... Figure 1-22 It works as shown in the diagram, in a cutting or blade-type grinding machine. To avoid repetition, refer to the description here and incorporate it into this document.

[0147] It will be apparent to those skilled in the art that the embodiments described above should be understood as exemplary, and that the invention is not limited to these embodiments, but can be varied in many ways without departing from the scope of the claims. The corresponding components of the exemplary cutting and grinding machines and blade grinders are interchangeable, wherein the safety cover 19 of the blade grinder or stamping grinder functions functionally equivalent to the grinding machine housing door 18 of the cutting and grinding machine, the impact cross grinder, or the disc grinder.

Claims

1. A laboratory grinder (1) for pulverizing and grinding materials, comprising a cutting grinder, an impact cross grinder, a disc grinder, a blade grinder, or a stamping grinder, wherein the laboratory grinder includes Equipment housing (12), grinding machine housing (16) or grinding container (17), A grinding chamber (82) is located in the grinding machine housing (16) or the grinding container (17), wherein, A grinding machine (84) can be arranged in the grinding chamber (82) to pulverize the grinding material, and wherein the grinding machine housing (16) or the grinding container (17) has a user access opening (94). A grinding machine housing door (18) or safety cover (19) for closing the user access opening (94), wherein the grinding machine housing door (18) or the safety cover (19) has an open state and a closed state, wherein, in the open state of the grinding machine housing door (18) or the safety cover (19), the user can access the grinding machine (84) through the user access opening (94). Grinding drive unit (2, 4) for driving grinding machine (84), The grinding machine housing door (18) or safety cover (19) has a closing element (22), which allows the grinding machine housing door (18) or safety cover (19) to be locked in the closed state. The laboratory grinder (1) has a mechanical grinding machine drive locking device (74). The grinding machine drive locking device (74) of the machine has a form-fitting coupling member (60), which releases the grinding machine drive device (2, 4) in a disengaged state and forms-fittingly locks the grinding machine drive device (2, 4) in an engaged state. The form-fitting coupling member (60) includes a stator coupling part (56) connected to the equipment housing (12) and a rotor coupling part (58) connected to a rotating component of the grinding machine drive device or the grinding machine (84). The stator coupling part (56) and the rotor coupling part (58) form-fittingly lock the rotation of the grinding machine (84) in an engaged state.

2. The laboratory grinder (1) according to claim 1, wherein, The grinding machine drive locking device (74) is operated by the closing element (22), and when the closing element (22) is opened, the closing element (22) locks the grinding machine drive locking device (74) of the machine, wherein the grinding machine drive devices (2, 4) are locked, and when the closing element (22) is closed, the closing element (22) unlocks the grinding machine drive locking device (74) of the machine, wherein the grinding machine drive devices (2, 4) are released.

3. The laboratory grinder (1) according to any one of the preceding claims, wherein, The device includes a mechanical operating mechanism (66), and when the grinding machine housing door (18) or the safety cover (19) is closed, the closing element (22), the mechanical operating mechanism (66), and the grinding machine drive locking device (74) form a mechanical operating chain (65), wherein the movement of the closing element (22) is mechanically transmitted to the grinding machine drive locking device (74) through the mechanical operating chain (65) to lock or unlock the grinding machine drive locking device (74).

4. The laboratory grinder (1) according to claim 1, wherein, When the closing element (22) is opened, the grinding machine drive locking device (74) of the machine is first locked and the grinding machine drive device (2, 4) is locked. The grinding machine housing door (18) or safety cover (19) is mechanically locked by the closing element (22) as long as the grinding machine drive locking device (74) of the machine is not locked. When the closing element (22) is closed, the grinding machine housing door (18) or safety cover (19) is first locked and the grinding machine drive locking device (74) of the machine is unlocked and the grinding machine drive device (2, 4) is released only after the grinding machine housing door (18) or safety cover (19) is locked.

5. The laboratory grinder (1) according to claim 1, wherein, The grinding machine drive device includes a drive motor (4) and a drive shaft (2), the drive shaft being connected to the grinding machine (84) to drive the grinding machine (84), and wherein, when the grinding machine housing door (18) or the safety cover (19) is not locked, the grinding machine drive locking device (74) of the machine acts on the drive shaft (2) and mechanically locks the rotation of the drive shaft (2).

6. The laboratory grinder (1) according to claim 1, wherein, The shape-fitting coupling (60) engages and disengages by axial movement of the stator coupling (56) or the rotor coupling (58) in order to lock and unlock the grinding machine drive locking device (74).

7. The laboratory grinder (1) according to claim 5, wherein, The shape-fitting coupling member (60) includes a stator coupling ring (57) and a rotor coupling ring (59) arranged around the drive shaft (2), wherein the stator coupling ring (57) is fixed to the device housing (12), and the drive shaft (2) rotates in the stator coupling ring (57) in the disengaged state of the coupling member (60), and wherein the rotor coupling ring (59) is fixed to the drive shaft (2).

8. The laboratory grinder (1) according to claim 1, wherein, The machine includes a mechanical operating device (66) that, when the grinding machine housing door (18) or the safety cover (19) is closed, has a closing element (22) coupled to the mechanical operating device, and the mechanical operating device mechanically transmits the motion of the closing element (22) to the grinding machine drive locking device (74) when the grinding machine housing door (18) or the safety cover (19) is locked and unlocked.

9. The laboratory grinder (1) according to claim 8, wherein, The closure element (22) and the operating device (66) of the machine have complementary coupling elements (34, 36) that are coupled to each other when the grinding machine housing door (18) or the safety cover (19) is closed, and discoupled from each other when the grinding machine housing door (18) or the safety cover (19) is opened. In the coupled state, the movement of the closure element (22) is mechanically transmitted to the grinding machine drive locking device (74) via the coupled coupling elements (34, 36) and the operating device (66) of the machine, so as to unlock the grinding machine drive locking device (74) and release the grinding machine drive (2, 4) when the closure element (22) is closed, and lock the grinding machine drive locking device (74) and lock the grinding machine drive (2, 4) when the closure element (22) is opened.

10. The laboratory grinder (1) according to claim 1, wherein, The closing element (22) includes a key (28) that engages in the closing sleeve (30) and locks and unlocks the grinding machine housing door (18) or the safety cover (19) by rotating the key (28) in the closing sleeve (30), and manipulates the unlocking and locking of the grinding machine drive locking device (74).

11. The laboratory grinder (1) according to claim 1, wherein, It includes a lateral slider (44), and the manipulation of the closing element (22) causes the lateral slider (44) to move laterally.

12. The laboratory grinder (1) according to claim 8, wherein, The machine includes a lateral slider (44), and the operating device (66) of the machine includes an operating shaft (38) and an eccentric disk (40) connected to the operating shaft (38), wherein the operating shaft (38) is rotated by the closing element (22), and the eccentric disk (40) converts the rotational motion into lateral movement of the lateral slider (44).

13. The laboratory grinder (1) according to claim 8, wherein, It includes a control device and an electrically activatable retaining device (72), and when the laboratory grinder (1) is running, the control device activates the retaining device (72), wherein the activated retaining device (72) holds the operating device (66) of the machine and prevents the closing element (22) from moving by means of the retaining, and wherein when the grinder drive (2, 4) stops, the control device deactivates the retaining device (72).

14. The laboratory grinder (1) according to claim 8, wherein, When the closure element (22) is opened, the movement of the closure element (22) is transmitted to the grinding machine drive locking device (74) via a rigid mechanical coupling through the mechanical actuation device (66) to engage the form-fitting coupling member (60) and lock the grinding machine drive locking device (74). When the closure element (22) is closed, the movement of the closure element (22) is transmitted to the grinding machine drive locking device (74) via the mechanical actuation device (66) to unlock the grinding machine drive locking device (74). The separation of the form-fitting coupling member (60) is achieved by a spring force (70).

15. A laboratory grinder (1) for pulverizing and grinding materials, comprising a cutting grinder, an impact cross grinder, or a disc grinder, said laboratory grinder including Equipment housing (12) having a grinding machine housing (16), The grinding chamber (82) is located within the grinding machine housing (16), wherein, A grinding machine (84) can be arranged in the grinding chamber (82) to pulverize and grind materials, and wherein the grinding machine housing (16) has a user access opening (94). A grinding machine housing door (18) for closing the user access opening (94), wherein the grinding machine housing door (18) has an open state and a closed state, wherein, in the open state of the grinding machine housing door (18), a user can access the grinding machine (84) through the user access opening (94). Grinding drive unit (2, 4) for driving the grinding machine (84), The grinding machine housing door (18) has a door lock (22'), which allows the grinding machine housing door (18) to be locked in the closed state. The laboratory grinder (1) has a mechanical grinding machine drive locking device (74). The grinding machine drive locking device (74) of the machine has a form-fitting coupling member (60), which releases the grinding machine drive device (2, 4) in a disengaged state and forms-fittingly locks the grinding machine drive device (2, 4) in an engaged state. The form-fitting coupling member (60) includes a stator coupling part (56) connected to the equipment housing (12) and a rotor coupling part (58) connected to a rotating component of the grinding machine drive device or the grinding machine (84). The stator coupling part (56) and the rotor coupling part (58) form-fittingly lock the rotation of the grinding machine (84) in an engaged state.

16. A laboratory grinder (1) for pulverizing and grinding materials, comprising a blade grinder or a stamping grinder, the laboratory grinder including... Equipment housing (12) and grinding container (17), The grinding chamber (82) in the grinding container (17), wherein, A grinding machine (84) with a grinding rotor can be arranged in the grinding chamber (82) to crush and grind materials, and wherein the grinding container (17) has a user access opening (94). A safety cover (19) having an open state and a closed state, wherein the safety cover (19) in the open state allows a user to access the grinding machine rotor through a user access opening (94). Grinding machine drive unit (2, 4) for driving grinding machine rotor. The safety cover (19) has a closure element (22), which allows the safety cover (19) to be locked in the closed state. The laboratory grinder (1) has a mechanical grinding machine drive locking device (74). The grinding machine drive locking device (74) of the machine has a form-fitting coupling member (60), which releases the grinding machine drive device (2, 4) in a disengaged state and forms-fittingly locks the grinding machine drive device (2, 4) in an engaged state. The form-fitting coupling member (60) includes a stator coupling part (56) connected to the equipment housing (12) and a rotor coupling part (58) connected to a rotating component of the grinding machine drive device or the grinding machine (84). The stator coupling part (56) and the rotor coupling part (58) form-fittingly lock the rotation of the grinding machine (84) in an engaged state.

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