Patent Publication Number: US-2023160405-A1

Title: Quick-action clamping apparatus, pelletizing apparatus having such a quick-action clamping apparatus, related bracing method

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a National Stage Application of International Patent App. No. PCT/US2021/032854, filed May 18, 2021, which claims the benefit of European Patent Application No. 20176919.7, filed May 27, 2020, the entire disclosures of both of which are hereby incorporated by reference as if set forth in their entirety herein. 
    
    
     TECHNICAL FIELD 
     The invention concerns a quick-action clamping apparatus, in particular a one-hand quick-action clamping apparatus, for clamping a first assembly of a pelletizing apparatus to a second assembly of the pelletizing apparatus, in particular a pelletizer to a cutting chamber or a cutting chamber to an apertured plate, a bracing method and a clamping lever. 
     BACKGROUND 
     Clamping apparatuses for bracing assemblies of a pelletizing apparatus, in particular a pelletizer with a cutting chamber or a cutting chamber with an apertured plate are known from the state of the art. 
     In pelletizing apparatuses, the assemblies being the pelletizer and the cutting chamber, are typically designed to be separable from each other, in particular to be able to adapt the pelletizing apparatus to different materials to be processed and to facilitate cleaning and maintenance thereof. For that purpose, it has proven effective for the pelletizer to be arranged moveably, for example on a rail system, wherein the cutting chamber is usually arranged stationarily. 
     In that respect particular significance is attributed to securely connecting the components being the pelletizer and the cutting chamber in operation as, in operation of the pelletizing apparatus, high pressures occur, which urge the assemblies away from each other. To prevent that, clamping apparatuses are known from the state of the art. 
     Such clamping apparatuses usually have a plurality of closure clamping devices which are to be installed by an operator while at the same time the operator is pushing the pelletizer in the direction of the cutting chamber. Clamping apparatuses with closure clamping devices are also known, which are used for reversibly bracing a cutting chamber with an aperture plate of a pelletizing apparatus. 
     Although such closure clamping devices have proven effective for securely connecting the assemblies of a pelletizing apparatus, there is room for improvement. 
     SUMMARY 
     A disadvantage with the structures previously known from the state of the art is in particular that the operator has to carry out a number of movement sequences and changes in position for example to push the pelletizer in the direction of the cutting chamber and then install the plurality of closure clamping devices. 
     With that background in mind the object of the invention is to develop a clamping apparatus of the kind set forth in the opening part of this specification such that the disadvantages encountered in the state of the art are overcome to the best possible extent. In particular the invention seeks to provide a clamping apparatus which facilitates coupling of the assemblies of a pelletizing apparatus and bracing thereof. 
     According to the invention in a clamping apparatus of the first-mentioned kind that object is attained by a mounting element which is arranged at the first assembly or the second assembly, a locking element which is arranged at the other of the first assembly or the second assembly, and a clamping means having a clamping element, wherein the clamping element is mounted rotatably about an axis of rotation to the mounting element and the clamping element is adapted to be pivoted into a clamping position in which the clamping element is in engagement with the locking element and braces the first assembly against the second assembly. 
     The invention makes use of the realization that the procedure involved in coupling and bracing the assemblies by means of the quick-action clamping apparatus according to the invention can be made significantly easier. In comparison with structures previously known from the state of the art only one single movement is required to move the clamping means into the clamping position and to securely brace the assemblies, in particular the pelletizer to the cutting chamber. 
     In an equally simple fashion, the braced state is to be reversed by a movement of the clamping means in the opposite direction so that the assemblies can be separated from each other in order for example to carry out maintenance tasks or the like. 
     A development of the invention provides that the quick-action clamping apparatus has a second mounting element arranged at the same assembly as the first mounting element, a second locking element arranged at the same assembly as the first locking element, wherein the clamping means has a second clamping element which is mounted rotatably about a second axis of rotation to the second mounting element and the second clamping element is adapted together with the first clamping element to be pivoted into the clamping position in which the second clamping element is in engagement with the second locking element. 
     Such a redundant provision of the essential components of the quick-action clamping apparatus, namely the mounting element, the locking element and the clamping element, has been found to be advantageous for enhancing operational reliability and security. If improbable failure of one of the components should occur the redundant design ensures that the assemblies of the pelletizing apparatus still remain securely connected together in operation thereof. In addition, the bracing operation as well as release of the clamping state can be easily effected by a single movement of the clamping means which is coupled to both clamping elements. The provision of a second clamping element moreover advantageously permits the uniform application of a clamping force for bracing the assemblies. That further affords a sealed connection between the assemblies, that is safeguarded in particular against the escape of fluid. 
     In a preferred embodiment the clamping means further has a clamping lever connected to the at least one clamping element for actuating the at least one clamping element. Such a clamping lever has been found to be particularly advantageous for applications in which coupling and bracing of the assemblies is effected manually by an operator. In dependence on the arrangement of the clamping lever it can be moved not only for bracing the components themselves but also for moving the pelletizer in the direction of the cutting chamber. 
     According to a preferred embodiment the at least one clamping element has a hooked portion, wherein the hooked portion is adapted upon the pivotal movement of the clamping element into the clamping position to come into engagement with the locking element and to brace the locking element against the clamping element in the clamping position. The hooked portion performs a dual function. On the one hand it ensures bracing of the locking element against the clamping element in the clamping position and further serves to press the assemblies against each other as soon as the hooked portion comes into engagement with the locking element. In that way the operator is supported not only when locking the assemblies but also when coupling the assemblies together prior to applying the bracing action. 
     Preferably the hooked portion has a hook bottom, wherein the hook bottom is of a configuration corresponding to an external cross-section of the locking element. In that way the hook bottom ensures the transmission of adequate clamping forces and in addition reliably holds the locking element in the clamping position. 
     A further development of the invention provides that the hooked portion has a first limb and a second limb, wherein the limbs extend from the hook bottom and form a hook mouth and wherein the hook mouth forms a free cross-section between the limbs, which enlarges from the hook bottom in the direction of the limbs. 
     Such a configuration for the limbs or the hook mouth has proven to be particularly advantageous in order to press the assemblies against each other as soon as the locking element comes into engagement with the hook mouth. In other words the locking element is guided by the geometry of the hook mouth to the clamping position, which makes it easier for the operator to carry out the operation of coupling the assemblies and permits both coupling and also subsequent clamping by means of a single movement of the clamping means or the clamping lever. 
     In a preferred development the first limb and/or the second limb has a thickening which is arranged adjacent to the hook bottom and is adapted to hold the locking element in the clamping position. The thickening in question is moved past by the locking element when the clamping means is pivoted into the clamping position and in the clamping position provides that the locking element is securely held in the region of the hook bottom and the clamping means remains securely in the clamping position without the application of a force thereto. In an alternative embodiment the limb is of an angled configuration, in particular with a shallow angle, such that it holds the locking element self-lockingly in the clamping position. 
     Preferably the clamping element further has an eccentric portion, the eccentric portion being of such a configuration that in the movement of the clamping element out of the clamping position the eccentric portion applies a force to the locking element which separates the first assembly from the second assembly. This preferred embodiment makes use of the realization that, in relation to pelletizing apparatuses, high forces are possibly to be applied to the pelletizer by the operator in order to separate it from the cutting chamber for performing maintenance tasks and the like. The eccentric portion provides that, in a movement of the clamping element out of the clamping position, a force which separates the assemblies from each other is applied to the locking element. 
     A further development of the invention provides that the eccentric portion has an area centroid corresponding to the axis of rotation of the clamping element. It is further preferred that one of the limbs is provided by the eccentric portion. 
     According to a preferred embodiment the eccentric portion, in that region of the limb, that is adjacent to the hook bottom, has a first radius in relation to the area centroid, that radius increasing with an increasing distance from the hook bottom along the limb, in particular linearly or non-linearly. 
     The operating force applied to the clamping means by the operator can be transmitted as desired, in dependence on the design configuration of the eccentric portion. Thus for example a slight increase in the radius along the limb or in other words a slight inclination of the eccentric portion provides that for a given distance of movement and a force for movement of the clamping means, a higher force is applied to the mounting element, but same is urged away from the axis of rotation of the mounting element only by a short distance. A greater inclination of the eccentric portion, with the same force applied to the clamping means and the same distance of movement, has the result that the locking element is urged further away from the axis of rotation, but only a lower force is transmitted to same. 
     In a preferred embodiment the locking element and/or the mounting element is in the form of a pin. In that case the locking element and the mounting element preferably involve the same geometry. That improves the interoperability of the components. 
     A development of the invention provides that the quick-action clamping apparatus has a drive device for driving the clamping means, wherein the drive device has or is formed from in particular at least one of the following: an electric motor, a hydraulic actuator or a pneumatic drive, in particular having a cylinder drive and/or a rotary drive. For application situations in which the assemblies are not to be manually coupled and/or braced it has proven to be advantageous to provide a drive device for driving the clamping means. 
     Preferably the quick-action clamping apparatus has a sensor device for sensing the position of the clamping means. In a preferred embodiment the sensor device is arranged at the pelletizer and/or is adapted to generate a signal when the clamping means is in the clamping position and/or is moved out of same. 
     In an alternative embodiment the sensor device is connected in signal-conducting relationship to a control device of the pelletizing apparatus, wherein the control device is adapted to stop the pelletizing apparatus when the clamping means if moved out of the clamping position. It is further preferred for the control device to be adapted to start the pelletizing apparatus after the clamping means has been moved into the clamping position. 
     In a further preferred configuration, the quick-action clamping apparatus has a locking means, in particular an electromechanical locking means, adapted to hold the clamping means in the clamping position and/or to release same from the clamping position. That prevents the clamping means being inadvertently moved out of the clamping position during operation of the pelletizing apparatus. 
     An advantageous development provides that the clamping lever has two spaced clamping lever limbs and a handle connecting the clamping lever limbs. The two clamping lever limbs provide a mechanically particularly strong and reliable holding action and the quick-action clamping apparatus can be very easily and efficiently operated by means of the handle. 
     It is advantageous in regard to a compact but nonetheless highly functional connection to one of the assemblies if the clamping lever, in particular its two spaced clamping lever limbs has a first clamping lever portion coupled to the clamping element and a second clamping lever portion extending at an angle relative to the first clamping lever portion and preferably a third clamping lever portion which extends at an angle relative to the second clamping lever portion and at the distal end of which the handle is fixed. The angles can preferably be so selected that the lever permits the application of a good torque and at the same time preferably good mechanical actuation is possible with sufficient space and without the hand being trapped. 
     It is particularly advantageous in regard to reliable secure bracing if the clamping lever is mounted pivotably to the first assembly or the second assembly of the pelletizing apparatus in such a way that the clamping lever moves beyond a dead center point in the manner of a toggle lever in the clamping operation and/or self-locking clamping ensues. 
     The invention has been described hereinbefore with reference to a quick-action clamping apparatus. In a further aspect the invention concerns a pelletizing apparatus for the production of pellets from a melt flow, comprising a pelletizer and a cutting chamber. 
     The invention attains the object set forth in the opening part of this specification in relation to the pelletizing apparatus by same having a quick-action clamping apparatus having a clamping means for bracing the pelletizer and the cutting chamber. 
     A development of the invention provides that the quick-action clamping apparatus is designed in accordance with one of the above-described preferred embodiments. 
     The pelletizing apparatus makes use of the same advantages and preferred configurations as the quick-action clamping apparatus according to the invention. In that respect attention is directed to the foregoing description and the content thereof is hereby incorporated. 
     In a further aspect the invention concerns a method of bracing a first assembly of a pelletizing apparatus to a second assembly of the pelletizing apparatus, in particular a pelletizer to a cutting chamber or a cutting chamber to an apertured plate. 
     The invention attains the object set forth in the opening part of this specification in relation to the method with the steps: providing the first assembly, in particular a pelletizer or an apertured plate; providing the second assembly, in particular a cutting chamber; and bracing the first assembly to the second assembly by means of a quick-action clamping apparatus, wherein the quick-action clamping apparatus is designed in accordance with one of the above-indicated and described embodiments. 
     The invention makes use of the same advantages and preferred embodiments as the quick-action clamping apparatus according to the invention. In that respect attention is directed to the foregoing description and the content thereof is hereby incorporated. 
     An advantageous development of the method provides that the clamping means is actuated by means of a clamping lever connected to the at least one clamping element, and the clamping lever is mounted pivotably to the first assembly or the second assembly of the pelletizing apparatus in the manner of a toggle lever and is rotated beyond a dead center point for the bracing effect and a self-locking bracing effect ensues. 
     In a further advantageous development for releasing the clamping action a force is applied to the locking element and thereby the first assembly is released from the second assembly, preferably at least somewhat spaced therefrom. 
     According to a further aspect to attain the object the invention further concerns a clamping lever which can be coupled to a clamping element for actuation of the clamping element of a quick-action clamping apparatus according to the invention for bracing a first assembly of a pelletizing apparatus to a second assembly of the pelletizing apparatus. According to the invention it is provided that the clamping lever has two spaced clamping lever limbs and a handle connecting the clamping lever limbs. 
     Additionally, or alternatively it is proposed that the clamping lever, in particular the two spaced clamping lever limbs thereof, has a first clamping lever portion coupled to the clamping element and a second clamping lever portion extending at an angle relative to the first clamping lever portion. 
     In regard to the further advantages and preferred features of the clamping element reference is directed to the foregoing and following description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention is described in greater detail hereinafter by means of preferred embodiments by way of example with reference to the accompanying Figures. 
       In the Figures: 
         FIGS.  1  and  2    show perspective views of a first embodiment by way of example of a pelletizing apparatus according to the invention, 
         FIG.  3    shows a plan view of the embodiment of the pelletizing apparatus according to the invention as shown in  FIGS.  1  and  2   , 
         FIG.  4    shows a detail view of the cutting chamber of the first embodiment of  FIGS.  1  to  3   , 
         FIG.  5    shows a perspective view of a clamping element according to the invention of the first embodiment, 
         FIG.  6    shows a perspective detail view of the pelletizing apparatus according to the invention according to the first embodiment, 
         FIGS.  7  and  8    show perspective views of an alternative embodiment of a pelletizing apparatus according to the invention, 
         FIG.  9    shows a plan view of the alternative embodiment of the pelletizing apparatus according to the invention shown in  FIGS.  7  and  8   , 
         FIG.  10    shows a detail view of the cutting chamber of the alternative embodiment of  FIGS.  7  to  9   , 
         FIG.  11    shows a perspective view of a clamping element according to the invention in accordance with the alternative embodiment, 
         FIG.  12    shows a perspective detail view of the pelletizing apparatus according to the invention in accordance with the alternative embodiment, and 
         FIG.  13    shows a further alternative embodiment of a quick-action clamping apparatus according to the invention. 
     
    
    
     DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS 
       FIG.  1    shows a pelletizing apparatus  2  for the production of pellets from a melt flow. The pelletizing apparatus  2  has a pelletizer  4  and a cutting chamber  6 . The cutting chamber  6  is arranged stationarily. The pelletizer  4  is arranged moveably on pelletizer rails  12  in such a way that the pelletizer  4  can be moved in the direction of the cutting chamber  6  and can be coupled thereto. 
     The pelletizer  4  has a base portion  22  on which a housing  24  is arranged. Arranged at the top side of the housing  24  is a base plate  26  at which a machine carrier  30  is disposed by means of spacer elements  28 . Disposed on the machine carrier  30  is a drive  14  driving a cutting blade  34 . The pelletizer  4  further has a protective hood  16 . The pelletizer  4  is a first assembly  36 . 
     Arranged on the pelletizer  4  are locking elements  40 ,  40 ′, in particular in that region of the pelletizer  4 , that is coupled to the cutting chamber  6 . The locking elements  40 ,  40 ′ are part of a quick-action clamping apparatus  8 . 
     The cutting chamber  6  is a second assembly  38 . The cutting chamber  6  has an inlet for process water  20  and an outlet  18  for process water and pellets. Pelletization and cutting of a supplied melt is effected in the cutting chamber  6 , in which case both process water and also pellets issue from the cutting chamber  6  from the outlet  18 . 
     A clamping means  10  is arranged at the cutting chamber  6 . The clamping means  10  has a clamping element  32 . The clamping element  32  is mounted rotatably to a mounting element  44  (see  FIG.  3   ). The clamping means  10  has a clamping lever  42  connected to the clamping element  32 . 
       FIG.  2    shows the pelletizing apparatus  2  of  FIG.  1   , with the clamping means  10  here being in a clamping position S. In the clamping position S, the pelletizer  4  is braced to the cutting chamber  6  by means of the quick-action clamping apparatus  8 . In that situation the clamping element  32  is in engagement with the locking element  40  and braces the first assembly  36  against the second assembly  38 . Further details in that respect are shown in  FIG.  3   . 
       FIG.  3    shows a plan view of the pelletizing apparatus  2  including the pelletizer  4  and the cutting chamber  6 . As can be seen from  FIG.  3    at its top side in the region adjacent to the cutting blade  34  the pelletizer  4  has the locking element  40  which has an external cross-section indicated at  41 . The locking element  40  is in the form of a pin  45 . The clamping element  32  arranged at the cutting chamber  6  is mounted on a mounting element  44  rotatably about an axis of rotation D. The clamping lever  42  is connected to the clamping element  32 . A pivotal movement of the clamping lever  42  provides that the clamping element  32  connected to the clamping lever  42  rotates about the axis of rotation D. The mounting element  44  is arranged at a pin holder  46  connected to the cutting chamber  6 . The clamping element  32  is adapted after the movement of the pelletizer  4  in the direction of the cutting chamber  6  to come into engagement with the locking element  40  and to be pivoted into the clamping position S shown in  FIG.  2   . 
       FIG.  4    shows a perspective view of the cutting chamber  6 . The cutting chamber  6  has essential parts of the quick-action clamping apparatus  8 . The quick-action clamping apparatus  8  has the first clamping element  32  and a second clamping element  32 ′. Both clamping elements  32 ,  32 ′ are connected to the clamping lever  42  by means of a connecting screw  48 . A movement of the clamping lever  42  also results in a movement of the two clamping elements  32 ,  32 ′. 
     As already stated in relation to  FIG.  3    the clamping element  32  is mounted to the mounting element  44  about the axis of rotation D. The mounting element  44  is arranged on the pin holder  46 . The clamping element  32 ′ is mounted to the mounting element  44  rotatably about an axis of rotation (not shown). The clamping elements  32 ,  32 ′ each have a respective hooked portion  50 . In addition, the clamping elements  32 ,  32 ′ have an eccentric portion  52 . The eccentric portion  52  is of such a configuration that, in the movement of the clamping elements  32 ,  32 ′ out of the clamping position S shown in  FIG.  2   , the eccentric portion exerts a force on the locking elements  40 ,  40 ′. As a result, the first assembly  36  is separated from the second assembly  38  (see  FIG.  2   ). 
       FIG.  5    shows a clamping element  32 ,  32 ′. The clamping element  32 ,  32 ′ can be connected to the clamping lever  42  by means of the threaded bore  54  (see for example  FIG.  4   ). Alternatively, the clamping element  32 ,  32 ′ and the clamping lever  42  can be formed in one piece. The clamping element  32 ,  32 ′ has a hooked portion  50 . The hooked portion  50  is formed by a hook bottom  56  as well as a first limb  58  and a second limb  58 ′. The limbs  58 ,  58 ′ define a hook mouth  60 . The hook mouth  60  forms a free cross-section d between the limbs  58 ,  58 ′. The free cross-section d enlarges from the hook bottom  56  in the direction of the limbs  58 ,  58 ′. In the present case the first limb  58  has a thickening  62 . The thickening  62  is arranged adjacent to the hook bottom  56 . The thickening  62  is adapted to hold the locking element  40  (see for example  FIG.  3   ) in the clamping position S. Alternatively, the first limb  58  can be of an angled configuration such that it holds the locking element  40  (see  FIG.  3   ) in the clamping position S in a self-locking relationship. 
     The clamping element  32 ,  32 ′ further has an eccentric portion  52 . The eccentric portion  52  is of such a configuration that, in the movement of the clamping element  32 ,  32 ′ out of the clamping position S, it exerts a force on the locking element  40 ,  40 ′ (see  FIG.  3   ). The eccentric portion  52  has an area centroid  64  corresponding to the axis of rotation D of the clamping element  32 ,  32 ′. The eccentric portion  52  forms the limb  58 ′. In the region of the hook bottom  56  the eccentric portion  52  has a first radius r 1  which is smaller than a radius r 2  which is to be found on the second limb  58 ′ further away from the hook bottom  56 . The increase in radius between the radius r 1  and the radius r 2  is linear, optionally non-linear. 
       FIG.  6    shows a detail view of the pelletizer  4  and the cutting chamber  6  in a coupled but non-locked state. Arranged on the pelletizer  4  adjacent to the machine carrier  30  is a sensor device  66 . The sensor device  66  is adapted to generate a signal when the clamping means  10  or the clamping lever  42  is moved out of the clamping position S (see  FIG.  2   ). The generated signal can be used for example to stop the pelletizer, to start it, or to prevent operation of the pelletizer  4  when the clamping means  10  and the clamping lever  42  are in the position shown in  FIG.  6   . 
     In addition, a locking device  68 , in particular an electromechanical locking device  68 , is arranged on the pelletizer  4 . The locking device  68  is adapted to selectively hold fast or release a locking means  70  arranged on the clamping lever  42 . In other words, the locking device  68  ensures that, when the clamping means  10  is in the clamping position S and the pelletizer  4  as well as the cutting chamber  6  are being operated, the clamping lever  42  cannot be moved out of the clamping position S, for example inadvertently. As soon as the pelletizer  4  and the cutting chamber  6  are no longer in operation the locking device  68  is adapted to release the clamping lever  42  and therewith the clamping means  10 . The clamping lever  42  can now be moved out of the clamping position S. 
       FIGS.  7  to  12    show an alternative embodiment of a pelletizing apparatus  102 . The pelletizing apparatus  102  has a pelletizer  104  and a cutting chamber  106 . The cutting chamber  106  is arranged stationarily. The pelletizer  4  is arranged moveably on pelletizer rails  112 . The pelletizing apparatus  102  has a quick-action clamping apparatus  108 . The quick-action clamping apparatus  108  has a clamping means  110 , with two clamping elements  132 ,  132 ′. 
     In contrast to the first embodiment of  FIGS.  1  to  6    the clamping elements  132 ,  132 ′ are now arranged at the pelletizer  104 . Equally locking elements  140 ,  140 ′ (see  FIG.  9   ) are now arranged at the cutting chamber  106 . 
     The pelletizer  104  has a base portion  122  and a housing  124  in a structure which is already known. Disposed at the top side of the housing  124  is a base plate  126 , above which is arranged a machine carrier  130  spaced from the base plate  126  by spacer elements  128 . Arranged on the machine carrier  130  is a drive  114  which drives a cutting blade  134  in rotation. The pelletizer  104  further has a protective hood  116 . The clamping elements  132 ,  132 ′ are respectively mounted to a mounting element  144 ,  144 ′. The clamping means  110  further has a clamping lever  142  connected to the clamping elements  132 ,  132 ′ for actuating the clamping elements  132 ,  132 ′. The pelletizer  104  is a first assembly  136 ; the cutting chamber  106  is a second assembly  138 . 
     The cutting chamber  106  has an inlet  120  for process water which feeds process water to the cutting chamber  106  and an outlet  118  for process water and pellets from which process water and pellets issue from the cutting chamber  106 . In  FIG.  7    the pelletizer  104  and the cutting chamber  106  are shown separated from each other. Maintenance operations on the pelletizer  104  and/or the cutting chamber  106  can be performed in the illustrated operative position. 
       FIG.  8    shows the components described with reference to  FIG.  7    in a clamping position S. The pelletizer  104  is now coupled to the cutting chamber  106 . The clamping elements  32 ,  32 ′ (see  FIG.  7   ) are in the clamping position S. The clamping elements  132 ,  132 ′ are in engagement with locking elements  140 ,  140 ′ (see  FIG.  9   ) and brace the first assembly  136  to the second assembly  138 . 
       FIG.  9    shows a plan view of the pelletizing apparatus  102 . In relation to the cutting chamber  106  it is now possible to see the locking element  140  arranged at the top side thereof. The locking element  140  has an external cross-section indicated at  141 . Referring to the pelletizer  4  the components which are visible from above of the quick-action clamping apparatus  108 , including the clamping means  110 , can be seen there. The clamping element  132  is mounted to a mounting element  144  rotatably about an axis of rotation D. The clamping element  132  has a hooked portion  150 . That hooked portion  150  is of a configuration corresponding to the external cross-section  141  of the locking element  140  in such a way that, in the pivotal movement of the clamping element  132  into the clamping position S, the portion  150  comes into engagement with the locking element  140  and braces the locking element  140  against the clamping element  132  in the clamping position S. 
       FIG.  10    shows a detail view of the cutting chamber  106  which represents the second assembly  138 . The cutting chamber  106  has the inlet  120  for process water and the outlet  118  for process water and pellets in known manner. Pin holders  146  are respectively arranged adjacent to the outlet  118  and the inlet  120 . Arranged at the pin holders  46  is a respective locking element  140 ,  140 ′. The clamping elements  132 ,  132 ′ (see  FIG.  12   ) come into engagement with the locking elements  140 ,  140 ′ in the clamping position S. 
       FIG.  11    shows a detail view of the clamping element  132 ,  132 ′. The clamping element  132 ,  132 ′ has threaded bores  154  for fixing the clamping element  132 ,  132 ′ to the clamping lever  142 . The clamping element  132 ,  132 ′ has the hooked portion  150 . The hooked portion  150  has a hook bottom  156 , the hook bottom  156  being of a configuration corresponding to the external cross-section  141  of the locking element  140  (see  FIG.  10   ). The locking elements  140 ,  140 ′ are in the form of pins  145 . The hooked portion  150  further has a first limb  158  and a second limb  158 ′. The limbs  158 ,  158 ′ extends from the hook bottom  156  and form a hook mouth  160 . The hook mouth  160  forms a free cross-section d between the limbs  158 ,  158 ′. The free cross-section d enlarges from the hook bottom  156  in the direction of the limbs  158 ,  158 ′. 
     The first limb  158  has a thickening  162 . The thickening  162  is arranged adjacent to the hook bottom  156 . The thickening  162  is adapted to hold the locking element  140 ,  140 ′ (see  FIG.  8   ) in the clamping position S. The first limb  158  can alternatively be of an angled configuration, in particular with a shallow angle, in such a way that it holds the locking element  140 ,  140 ′ (see  FIG.  8   ) in the clamping position S in self-locking relationship. The clamping element  132 ,  132 ′ further has an eccentric portion  152 . The configuration of the eccentric portion  152  is such that, in the movement of the clamping element  132 ,  132 ′ out of the clamping position S, it exerts a force on the locking element  140 ,  140 ′ (see  FIG.  8   ). The eccentric portion  152  has an area centroid  164  corresponding to the axis of rotation D of the clamping element  132 ,  132 ′. The limb  158 ′ is formed by the eccentric portion  152 . 
       FIG.  12    shows the cutting chamber  106  and the quick-action clamping apparatus  108  in a coupled state in which however it is not yet completely braced. The clamping elements  132 ,  132 ′ are in engagement with the locking elements  140 ,  140 ′ (lower locking element  140 ′ is not visible). When, starting from the position shown in  FIG.  12   , the clamping lever  142  is moved in the direction of the pelletizer  104  then the clamping element  132  comes further into engagement with the locking element  140  and braces the first assembly  136  to the second assembly  138 . When, however, the clamping lever  142  is moved in the opposite direction away from the pelletizer  104  in the direction of the cutting chamber  106  then the eccentric portion  152  of the clamping element  132  urges the locking element  140  away from the pelletizer  104 . The consequence of this is that the pelletizer  104  which is mounted moveably is urged away from the stationarily arranged cutting chamber  106 . That facilitates uncoupling the first assembly  136  from the second assembly  138  by a movement of the clamping lever  142 . 
     The pelletizer  104  has a sensor device  166  adapted to sense the position of the clamping lever  142 . In addition, the pelletizer  104  has an electromechanical locking device  168  adapted to selectively hold or release the locking means  170  when the clamping means  110  is in the clamping position S. 
     Further features of the clamping levers can be seen for both embodiments from the Figures, in particular  FIGS.  3 ,  4 ,  6 ,  9  and  12   . The clamping lever  42 ,  142  has two spaced clamping lever limbs  43 ,  143  and a handle  47 ,  147  connecting the clamping lever limbs  43 ,  143 . 
     The clamping lever  42 ,  142 , in particular the two spaced clamping lever limbs  43 ,  143  thereof, has a first clamping lever portion  49 ,  149  coupled to the clamping element  32 ,  32 ′,  132 ,  132 ′, and a second clamping lever portion  51 ,  151  extending at an angle relative to the first clamping lever portion  49 ,  149 , and preferably a third clamping lever portion  53 ,  153  which extends at an angle relative to the second clamping lever portion  51 ,  151  and at the distal end of which is fixed the handle  47 ,  147 . The clamping lever  42 ,  142  is thus pivotably mounted to the first assembly  36 ,  136  or the second assembly  38 ,  138  of the pelletizing apparatus  2 ,  102  in such a way that the clamping lever  42 ,  142  passes beyond a dead center point in the bracing operation in the manner of a toggle lever and a self-locking bracing action ensues. 
     As can be clearly seen for example from  FIGS.  3  and  9    the first clamping lever portion  49  is shorter than and is at an angle of about 90° relative to the second clamping lever portion  51 ,  151 . The first clamping lever portion  49 ,  149  is preferably releasably connected to the clamping element  32 ,  32 ′,  132 ,  132 ′ by means of the threaded bores  54 . The angle between the first and second clamping lever portions  49 ,  149 ,  51 ,  151  and also the respective lengths in the respective axial direction could vary and assume different ranges of values. The angle between the second clamping lever portion  49 ,  149 ,  51 ,  151  and the third clamping lever portion  53 ,  153  is markedly greater than 90°, in the illustrated embodiment approximately in the region of 170°, but it would also be possible to implement an angular range of for example between 180° and 90°. The third clamping lever portion  53 ,  153  is so selected that the handle  47 ,  147  fixed to the two clamping lever portions  49 ,  149  can be readily gripped, even and in particular in the clamping position S, so that a hand or finger can pass between the handle  47 ,  147  and the oppositely disposed assembly, in particular a pelletizer  4 ,  104  or a cutting chamber  6 ,  106 , and the hand is not trapped. Very roughly the clamping lever limbs in the plan view ( FIG.  3   ,  FIG.  9   ) bear a similarity to an S-shape. 
     The method according to the invention and the mode of operation of the quick-action clamping apparatus and the components thereof are further described hereinafter: 
     For bracing a pelletizer  4 ,  104  shown by way of example to a cutting chamber  6 ,  106  (other assemblies are also included in accordance with the invention) firstly the pelletizer  4 ,  104  and the cutting chamber  6 ,  106  are provided in mutually relative relationship ( FIGS.  1 ,  3 ,  6 ,  9  and  12   ). Then the quick-action clamping apparatus is actuated, either by means of drive means or manually, so that the clamping means  10 ,  110  come into engagement with the clamping element  32 ,  132  relative to the locking element  40 ,  140  and the first and second assemblies  36 ,  136 ,  38 ,  138  are braced relative to each other. During that rotary movement, in the illustrated embodiment by actuation of the handle  47 ,  147 , the clamping lever which is designed in the manner of a toggle lever passes over a dead center point at which the relative bracing is at a maximum and then passes by further rotary movement beyond that dead center point, during which the bracing decreases somewhat. As a result, a self-locking bracing action is achieved in that region. In the clamping position the handle  47 ,  147  is arranged at a minimum spacing in relation to the pelletizing apparatus  2 ,  102 . The spacing is so selected by virtue of the above-described configuration that a hand can engage between the pelletizing apparatus  2 ,  102  and the handle  47 ,  147  without being trapped. For release purposes the clamping element  32 ,  32 ′,  132 ,  132 ′ is rotated in the opposite direction and during the rotation in that direction a force is applied to the locking element  40 ,  40 ′,  140 ,  140 ′ by the eccentric portion  52 ,  152  of the clamping element  32 ,  32 ′,  132 ,  132 ′ so that the first and second assemblies  36 ,  136 ,  38 ,  138  are released relative to each other and preferably at least partially spaced from each other. 
       FIG.  13    shows a block circuit diagram of a further embodiment of a quick-action clamping apparatus  208 . The quick-action clamping apparatus  208  has a clamping means  210 . A drive device  272  is arranged at the clamping means  210 . The drive device  272  serves to drive the clamping means  210 . The drive device  272  has an electric motor  274 , a hydraulic actuator  276  and/or a pneumatic drive  278 . The pneumatic drive  278  has a cylinder drive  280  and/or a rotary drive  282 . 
     LIST OF REFERENCES 
     
         
           2  pelletizing apparatus 
           4  pelletizer 
           6  cutting chamber 
           8  quick-action clamping apparatus 
           10  clamping means 
           12  pelletizer rails 
           14  drive 
           16  protective hood 
           18  outlet for process water and pellets 
           20  inlet for process water 
           22  base portion 
           24  housing 
           26  base plate 
           28  spacer elements 
           30  machine carrier 
           32 ,  32 ′ clamping element 
           34  cutting blade 
           36  first assembly 
           38  second assembly 
           40 ,  40 ′ locking element 
           41  external cross-section of the locking element 
           42  clamping lever 
           43  clamping lever limb 
           44 ,  44 ′ mounting element 
           45  pin 
           46  pin holder 
           47  handle 
           48  connecting screws 
           49  first clamping lever portion 
           50  hooked portion 
           51  second clamping lever portion 
           52  eccentric portion 
           53  third clamping lever portion 
           54  threaded bores 
           56  hook bottom 
           58 ,  58 ′ first limb, second limb 
           60  hook mouth 
           62  thickening 
           64  area centroid 
           66  sensor device 
           68  electromechanical locking device 
           70  locking means 
           102  pelletizing apparatus 
           104  pelletizer 
           106  cutting chamber 
           108  quick-action clamping apparatus 
           110  clamping means 
           112  pelletizer rails 
           114  drive 
           116  protective hood 
           118  outlet for process water and pellets 
           120  inlet for process water 
           122  base portion 
           124  housing 
           126  base plate 
           128  spacer elements 
           130  machine carrier 
           132 ,  132 ′ clamping element 
           134  cutting blade 
           136  first assembly 
           138  second assembly 
           140 ,  140 ′ locking element 
           141  external cross-section of the locking element 
           142  clamping lever 
           143  clamping lever limb 
           144 ,  144 ′ mounting element 
           145  pin 
           146  pin holder 
           147  handle 
           148  connecting screws 
           149  first clamping lever portion 
           150  hooked portion 
           151  second clamping lever portion 
           152  eccentric portion 
           153  third clamping lever portion 
           154  threaded bores 
           156  hook bottom 
           158 ,  158 ′ first limb, second limb 
           160  hook mouth 
           162  thickening 
           164  area centroid 
           166  sensor device 
           168  electromechanical locking device 
           170  locking means 
           208  quick-action clamping apparatus 
           210  clamping means 
           272  drive device 
           274  electric motor 
           276  hydraulic actuator 
           278  pneumatic drive 
           280  cylinder drive 
           282  rotary drive 
         d free cross-section 
         D axis of rotation 
         S clamping position