Patent Publication Number: US-2023159314-A1

Title: Control cam for a clamping device, and clamping device for holding a container

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority from German Patent Application No. DE 10 2021 131 002.4, filed on Nov. 25, 2021 in the German Patent and Trademark Office, the disclosure of which is incorporated herein by reference in its entirety. 
     BACKGROUND 
     Technical Field 
     The present invention concerns a control cam for controlling the position of clamping arms, pivotable relative to one another, of a clamping device, and a clamping device for holding a container in a container treatment device, for example for holding a beverage container at a neck portion in order to fill or close this inside a beverage filling plant. 
     Related Art 
     It is known, in beverage filling plants, to transport containers to be filled or already filled through the individual treatment stations of the container treatment device by means of clamping devices. Various clamping devices are known which hold the respective containers to be treated in various ways. 
     For example, passive clamping devices are known which are elastically pretensioned purely by insertion of the respective container in the clamping device, and which then hold the container. DE 10 2012 218 204 A1 describes such a clamp for gripping containers. The clamp has a fixed position. In order to grip a container, the latter must be pushed into the clamp. The stiff gripper arms are here spread open, so that the container must be moved against the closing force of the gripper arms resulting from spreading of the clamp. Thus the container is exposed to a high force on insertion, so such holding devices are not suitable for gripping or holding fragile and/or easily deformable and thin-walled containers. There is at least a tendency to scratch the surfaces of the respective container, which reduces the quality of the containers. 
     Furthermore, active clamping devices are known in which the respective holding portions of the clamping device are actively opened and closed by means of an actuator. Such active clamping devices serve in particular to allow secure and gentle receiving of the respective containers from a preceding clamping device, or also a safe and gentle transfer of the containers to a following clamping device. In particular, the active opening and closure of the respective clamping device may avoid increased friction on the respective container, which could for example lead to scratching of the container, and secondly a predefined holding or clamping force may be set which can be maintained within a predefined tolerance range of the container dimensions. Such active clamping devices consist of a plurality of individual components, for example clamping arms, bushes, spring elements, pretension elements and corresponding connecting elements for secure connection of the above-mentioned parts. Clamping devices constructed in this way are also complicated to clean and have a correspondingly high production cost. 
     EP 0 939 044 A1 discloses a bottle gripper in which a gripping device is provided having two gripping arms which can be brought into a holding position or a release position by means of a control cam. The control cam cooperates with a contact face formed on each gripper arm, and the contact face is configured as part of an elastic cushion arranged on the respective gripper arm. 
     EP 2 143 674 A2 describes a clamping device for holding containers, in which two gripper arms or clamping arms are held in an open position by separate magnetic arrangements. The clamping arms have closing levers oriented towards the rear, which cooperate with a closing cam arranged in between in order to bring the clamping arms from the open position into a closed position. 
     DE 10 2005 014 838 A1 discloses an active clamping device for holding vessels, with two clamping arms which are movable relative to one another for opening and closing. In order to allow secure holding of the vessels, one gripper arm of the clamp is designed to be form-stable and the other gripper arm is form-elastic. The gripper arms are pretensioned in an open position by means of magnets arranged thereon, and are pivoted into the closed position by means of a control cam. 
     The common feature of the conventional, unilaterally pretensioned clamping devices is that the control cam has precisely one contact face for each clamping arm, via which it touches the clamping arm. On pivoting of the control cam, the contact face of the control cam slides over the contact face both during opening and during closing of the clamping arms via the pivoting of the control cam with said precisely one contact face. In so doing, the control cam exerts a force on the clamping arms in the opposite direction to the pretension from the pretension device. The force applied by the control cam to the clamping arms always points in the same direction. For example, with an active clamping device pretensioned in the closed position, the control cam must apply to the clamping arms a force opposite the pretension, in order to open the clamping arms. Usually, for this the control cam is configured so that its contact face has an increasing radius or distance from the pivot axis of the control cam in the circumferential direction, or a cam form as shown in DE 10 2005 014 838 A1. With its contact face towards the clamping arm, the control cam slides along the clamping arm. Because of the increasing radius or distance from the clamping arm at the contact point, the clamping arm is pressed out of its pretensioned position and pivoted about its pivot axis. To close the clamping arms, the control cam is again pivoted so that its contact face slides back over the clamping arm. Because of the reducing distance of the region of the contact face by which the control cam is in contact with the clamping arm, the clamping arm is pressed back again by the pretension force. 
     In clamping devices with unilateral pretension of the clamping arms in one position, wherein said arms can be moved into another position against the pretension by actuation of the control cam, and by release or automatic switching of the control cam moved back into the one pretensioned position, the process of return movement under pretension carries a degree of inertia. Accordingly, the container may be suddenly gripped and suddenly released from its holder. Furthermore, in such active clamping devices, a great deal of wear can occur between the clamping arms and control cam, in particular its contact face, since the latter must always work against the unilaterally directed pretension. 
     SUMMARY 
     An improved clamping device for holding a container in a container treatment device, for example for holding a beverage container at a neck portion is described herein according to various embodiments. 
     Accordingly, a control cam is proposed for controlling the position of clamping arms which are pivotable relative to one another, comprising a shaft portion for pivotable mounting of the control cam about a control cam pivot axis, in a hub portion of a carrier plate of the clamping device, and at least one coupling element for coupling the control cam to a clamping arm of the clamping device, wherein the control cam is pivotable about the control cam pivot axis between a predefined open position and a predefined closed position. 
     According to the invention, the control cam is characterized in that the at least one coupling element has at least one first coupling face which extends in the direction of the control cam pivot axis and is designed and configured for transmitting a first switching force onto one of the clamping arms, and a second coupling face which is different from the first coupling face and extends in the direction of the control cam pivot axis, and is designed and configured for transmitting a second switching force, directed opposite the first switching force, onto the clamping arm. 
     Because the at least one coupling element has a first coupling face which extends in the direction of the control cam pivot axis and is designed and configured for transmitting a first switching force onto one of the clamping arms, and a second coupling face which is different from the first coupling face and extends in the direction of the control cam pivot axis, and is designed and configured for transmitting a second switching force, directed opposite the first switching force, onto the clamping arm, via the coupling element a permanent forced guidance of the clamping arms can be provided both during opening and during closing, and in one embodiment also a pretension of the clamping arms in at least one predefined position, in some embodiments in an open position or a closed position of the clamping arms or holding portions of the clamping arms. 
     In other words, because of the coupling provided by the coupling element, the position and a movement of the clamping arms are always predefined by the position and movement of the control cam. Accordingly, both opening of the clamping arms to receive the respective container to be treated, and closing of the clamping arms for holding the container and subsequent opening to discharge the previously held container, are each actively controlled and guided by the control cam. 
     Accordingly, it can be prevented that, on a switching pulse to the control cam generating an abrupt movement of the control cam, the clamping arms and control cam briefly come out of engagement or lose contact with one another, as may be the case with unilaterally pretensioned conventional clamping devices with conventional control cam, such as if the spring force of the unilateral pretension is not sufficient, and then hit one another again. The gripping and release of the container to be held by the clamping device may thus take place comparatively gently without any uncontrolled impacts occurring on opening or closing of the clamping arms. 
     Furthermore, because of the permanent guidance provided by the coupling element and a corresponding coupling element formed on the clamping arm, a defined contact of the holding portions on the container to be held may be achieved. 
     A clamping device having a control cam configured in this fashion may accordingly, in comparison with conventional devices, be subjected to particularly low wear during operation, in particular in regions in which the clamping arms and control cam are coupled, which in turn has a positive effect on the service life of the control cam and components of the clamping device. 
     With a container treatment device having a clamping device comprising the control cam, in comparison with container treatment devices with conventional clamping devices, the service intervals may be extended because of the reduced wear. 
     Furthermore, because of the constantly force-guided movement of the holding portions and the reduction, in comparison with conventional clamping devices, or even avoidance of the occurrence of impacts during opening and/or closing of the clamping arms, controlled by the control cam, damage of the container to be held and/or the escape of product present in the container, such as a beverage, with associated contamination of the clamping device and other regions of a container treatment device with the clamping device or the outside of the container, may be reduced or even avoided. 
     The expression “pivot axis” means a geometric axis representing a rotational centre point, and herein describes in particular a fixed pivot axis, also an axis arranged stationarily with respect to the clamping device. The term “pivot axis” does not therefore mean a floating axis in the sense of a momentary pole. A body moving simultaneously rotationally and translationally in a plane does not pivot about a fixed axis; accordingly it has no pivot axis as understood here. 
     The geometric pivot axis may evidently be provided or configured in the form of a mechanical axle or shaft in the known fashion. For example, an axle journal, a pin or a bolt may be arranged on a carrier plate of the clamping device, on which for example a clamping arm is pivotably mounted in the sense of a shaft-hub connection. In the present case, the control cam comprises the shaft portion which is rotationally mounted in a bore in the carrier plate, and thereby provides the geometric axis. 
     The term “opposite” here means that the first switching force and the second switching force each have a circumferential component relative to the control cam pivot axis, wherein the circumferential component of the first switching force and the circumferential component of the second switching force are oriented opposite one another or in opposite directions. 
     The clamping arms of the clamping device which are pivotable relative to one another in one or more embodiments each have a holding portion, wherein the holding portions, depending on operating state of the clamping device, cooperate to receive, hold and discharge the respective container to be treated. 
     According to a further embodiment, the coupling faces of the least one coupling element are arranged on the coupling element opposite one another with respect to the coupling element, in particular its contour or cross-sectional contour perpendicularly to the control cam pivot axis. According to a further embodiment, the at least one coupling element is configured in the form of a slotted groove, in several embodiments for receiving a control bolt arranged on a clamping arm, or in the form of a control bolt in various embodiments for penetration into a slotted groove arranged on a control arm. In a particularly advantageous fashion, then a permanent or persistent forced guidance of at least one clamping arm of the clamping device can be provided by the control cam. 
     A “slotted groove” here means a groove which has substantially the form of a slot, and extends in a longitudinal extent from a first end to a second end, and between the two ends has side walls running substantially parallel to one another, or in other words transversely to the longitudinal extent at a fixed distance from one another, in some embodiments running straight or having an infinite radius of curvature. 
     The longitudinal extent of the slotted groove is here related to a plane oriented perpendicularly to the control cam pivot axis. In other words, the slot shape of the slotted groove is evident viewed in the direction of the control cam pivot axis. 
     The slotted groove in the sense of a groove extends as a depression in a body with the above-described slot shape, in the direction of the control cam pivot axis, with a predefined depth and/or at least partially through the entire body. 
     If the control cam comprises at least one control bolt, in a further embodiment the at least one control bolt extends in the direction of the control cam pivot axis with a predefined height from an end face of the shaft portion. 
     If the control cam comprises at least one slotted groove, in a further embodiment, the at least one slotted groove extends in the direction of the control cam pivot axis with a predefined depth into the control cam from an end face of the shaft portion. 
     In order to achieve a particularly precise and synchronous control of the holding portions of the clamping arms of the clamping device, according to a further embodiment, two coupling elements are provided, wherein a respective coupling element is configured for coupling the control cam to a respective one of the two clamping arms of the clamping device, wherein in certain embodiments a first coupling element, for example a first control bolt or a first slotted groove, has a first distance from the control cam pivot axis, and a second coupling element, for example a second control bolt or a second slotted groove, has a second distance from the control cam pivot axis, wherein the amount of the second distance is in various embodiments greater than that of the first distance. 
     According to a further embodiment, the at least one coupling element, for example the at least one control bolt or the at least one slotted groove, is arranged eccentrically to the control cam pivot axis. Thus the coupling element, relative to the control cam pivot axis, always provides a lever arm which, on pivoting of the control cam, always exerts a force on at least one clamping arm via its coupling to the corresponding coupling element on the clamping arm, in order to control the movement of the clamping arm, and/or on a holding force exerted on the container, held in the clamping device, via the holding portion of the clamping arm. 
     According to a further embodiment, the at least one control bolt comprises a portion which is curved, in one or more embodiments an arcuate portion, relative to a longitudinal centre axis of the control bolt which is oriented in various embodiments parallel to the control cam pivot axis. 
     Alternatively or in addition, the at least one control bolt may have a cam portion which extends in a plane oriented perpendicularly to the control cam pivot axis. 
     In several embodiments, at least one coupling face is arranged in the curved portion and/or in the cam portion. 
     If, according to a further embodiment, two control bolts are provided, the control bolts may be connected by a connecting wall, which in some embodiments may mean two interconnected cam portions, wherein a control bolt is assigned to each cam portion. 
     According to a further embodiment, the control cam comprises a radial locking groove for receiving a fixing element, for example a fitting key or a locking plate, in order to fix the control cam axially relative to the control cam pivot axis. 
     Alternatively or additionally, the at least one control bolt, viewed in the direction of the control cam pivot axis, at its free end opposite an end face of the shaft portion, has a locking web for axially securing the control cam to the clamping device. 
     In certain embodiments, the locking web is configured in the form of a in one embodiment circular flange which is arranged concentrically or eccentrically to the longitudinal centre axis of the control bolt, and the outer diameter of which is in various embodiments greater than a radius of an arcuate portion of the control bolt and/or in some embodiments greater than a width of the slotted groove provided on the clamping arm of the clamping device, transversely to its longitudinal extent. 
     According to a further embodiment, the control cam has an interaction part extending radially outward relative to the control cam pivot axis, for interaction with an interaction bolt of a container treatment device, wherein the interaction part is configured to limit a scope of movement of the control cam about the control cam pivot axis, wherein the interaction part is in some embodiments configured to cooperate with a stop of the clamping device, wherein the control cam in several embodiments has two arms extending radially outward relative to the control cam pivot axis. 
     According to a further embodiment, the control cam comprises a pretension element which is configured to interact with a stop element of the clamping device so that the control cam is pretensioned in the predefined open position when the control cam is in the predefined open position, and is pretensioned in the predefined closed position when the control cam is in the predefined closed position. 
     It has proved advantageous if, according to a further embodiment, the pretension element is configured as an elastic pretension element and/or as a magnetic pretension element. 
     According to a further embodiment, the pretension element comprises an elastic spring element, wherein the spring element has a curvature relative to the control cam pivot axis which is greater than a curvature of the geometric pitch circle, arranged concentrically to the control cam pivot axis, at the level of the spring element. 
     According to a further embodiment, the pretension element comprises a web extending radially outwardly relative to a geometric pitch circle arranged concentrically to the control cam pivot axis, and a spring element extending from the web transversely to the radial direction relative to the control cam pivot axis. In several embodiments a respective spring element extends on each side of the web relative to the control cam pivot axis. The at least one spring element is in various embodiments configured such that a distance is present between a free end of the spring element and an arm lying opposite the end of the spring element, so as to provide a receiver for receiving by form fit a running roller of the clamping device in the circumferential direction relative to the control cam pivot axis. 
     It has proved particularly suitable if, according to a further embodiment, the at least one spring element is configured as a curved leaf spring, in the form of a bolt spring-mounted radially relative to the control cam pivot axis, or in the form of a bending bar with a free end. 
     According to a further embodiment, the pretension element is configured in the form of a magnetic pretension element, wherein the magnetic pretension element comprises at least one magnetic element provided on an arm, wherein the magnetic pretension element in some embodiments comprises two magnetic elements each arranged in an arm, wherein the at least one magnetic element is arranged and configured so as to cooperate with a magnet of the clamping device when the control cam is fitted in the clamping device, such that a magnetic attraction force is present between the magnet and the magnetic element, at least when the control cam is in the predefined closed position and/or when the control cam is in the predefined open position. 
     Further advantageous embodiments and further advantageous effects can are given in the following description of exemplary embodiments. 
     A clamping device for holding a container in a container treatment device, for example for holding a beverage container at a neck portion is also described herein according to various embodiments. 
     Accordingly, a clamping device is proposed for holding a container in a container treatment device, for example for holding a beverage container at a neck portion, comprising two clamping arms with a holding portion for holding the container to be held. The clamping device is characterized in that the clamping arms are coupled to a control cam according to any of the preceding embodiments. 
     Because the clamping device has a control cam according to any of the preceding embodiments, the advantages and effects described above and below with respect to the control cam apply accordingly to the clamping device. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       Further embodiments of the invention are explained in more detail by way of the description of the figures that follows. 
         FIG.  1    shows schematically a perspective side view of a control cam for controlling the position of clamping arms, pivotable relative to one another, each having a holding portion, in a clamping device; 
         FIG.  2    shows schematically a perspective side view of a control cam according to a further embodiment; 
         FIG.  3    shows schematically a perspective side view of a control cam according to a further embodiment; 
         FIG.  4    shows schematically a perspective side view of a control cam according to a further embodiment; 
         FIG.  5    shows schematically a top view of the control cam from  FIG.  4   ; 
         FIG.  6    shows schematically a perspective side view of a control cam according to a further embodiment; 
         FIG.  7    shows schematically a perspective side view of a control cam according to a further embodiment; 
         FIG.  8    shows schematically a top view of the control cam from  FIG.  7   . 
         FIG.  9    shows schematically a further embodiment of a control cam; 
         FIG.  10    shows schematically a perspective side view of a clamping device for holding a beverage container at a neck portion; 
         FIG.  11    shows schematically a top view of a clamping device according to a further embodiment, in a closed position; 
         FIG.  12    shows schematically a top view of a clamping device from  FIG.  11    in an open position; 
         FIG.  13    shows schematically a top view of a clamping device according to a further embodiment, in a closed position; 
         FIG.  14    shows schematically a top view of a clamping device from  FIG.  13    in an open position; 
         FIG.  15    shows schematically a perspective side view of a clamping device according to a further embodiment; 
         FIG.  16    shows schematically a view from below of the clamping device from  FIG.  10   ; 
         FIG.  17    shows schematically a perspective side view from below of a part region of the clamping device from  FIG.  10   ; 
         FIG.  18    shows schematically a view from below of a clamping device according to a further embodiment; 
         FIG.  19    shows schematically a view from below of a clamping device according to a further embodiment; 
         FIG.  20    shows schematically a perspective side view of a clamping device according to a further embodiment; 
         FIG.  21    shows schematically a perspective side view of a clamping device according to a further embodiment; 
         FIG.  22    shows schematically a top view of a clamping device according to a further embodiment; 
         FIG.  23    shows schematically a top view of an upper part of a control cam, similar to the embodiment of  FIG.  22   ; 
         FIG.  24    shows schematically a side view of the part from  FIG.  23   ; 
         FIG.  25    shows schematically a clamping device according to a further embodiment; 
         FIGS.  26  and  27    show schematically top views of a detail of the control cam from  FIG.  1   ; and 
         FIGS.  28  and  29    show schematically top views of a detail of the control cam of the clamping device from  FIG.  22   . 
     
    
    
     DETAILED DESCRIPTION 
     Exemplary embodiments are described below with reference to the figures. In this case, elements that are identical, similar or have the same effect are provided with identical reference signs in the various figures and a repeated description of these elements is partly omitted in order to prevent redundancies. 
       FIG.  1    shows schematically a perspective side view of a control cam  20  for controlling the position of clamping arms  10 , pivotable relative to one another, each having a holding portion  11 , in a clamping device  1  (see also  FIG.  10   ). The control cam  20  comprises a shaft portion  26  for pivotable mounting of the control cam  20  about a control cam pivot axis  21 , in a hub portion  5  (not shown here) of a carrier plate  2  of the clamping device  1 . It furthermore comprises two elements for coupling the control cam  20  to the clamping arms  10  of the clamping device  1 . The coupling elements in the present case are each configured as a control bolt  32 ,  32 ′ arranged eccentrically to the control cam pivot axis  21 . 
     The control bolts  32 ,  32 ′ extend from an end face  27  of the shaft portion  26  in the direction of the control cam pivot axis  21 . Accordingly, they each have a respective longitudinal centre axis  325 ,  325 ′ which is oriented parallel to the control cam pivot axis  21 . 
     The control bolts  32 ,  32 ′ are each configured and designed to interact with a respective slotted groove  31  (see  FIG.  10   ) arranged on the clamping arm  10  to be controlled by the control bolt  32 ,  32 ′, or to form a coupling therewith. The coupling is configured such that the respective control bolt  32 ,  32 ′ is guided in its assigned slotted groove  31 , in some embodiments in that it can move translationally along the slotted groove  31  or along a longitudinal extent  310  of the slotted groove  31  which extends perpendicularly to the control cam pivot axis  21 , and can in various embodiments move rotationally relative to the slotted groove  31 , for example via rolling on and/or sliding over a side wall  311  of the slotted groove  31 . 
     Alternatively, the control cam  20  may also have coupling elements in the form of a slotted groove  31 , as explained in more detail below with reference to  FIGS.  22  to  24   . Accordingly, the slotted groove  31  then extends in the direction of the control cam pivot axis  21  with a predefined depth into the control cam from the end face  27  of the control cam  20 . Furthermore, the slotted groove  31  is configured to receive a control bolt  32  assigned to the slotted groove  31  and arranged on the clamping arm  10  to be controlled, and thereby provide a guidance for the control bolt  32  along the longitudinal extent  310  of the slotted groove  31 , in several embodiments translationally and rotationally, as described above with respect to the control bolt  32 ,  32 ′ according to  FIG.  1   . 
     In the embodiment shown in  FIG.  1   , the first control bolt  32  has a radial distance  320  from the control cam pivot axis  21  which is smaller by a predefined amount than the radial distance  320 ′ of the second control bolt  32 ′ from the control cam pivot axis  21 . The distances  320 ,  320 ′ here relate to the centre longitudinal axes  325 ,  325 ′. 
     Because the control bolts  32 ,  32 ′ are arranged at different radial distances  320 ,  320 ′ from the control cam pivot axis  21 , a symmetrical pivoting of the two clamping arms  10  of the clamping device  1  having the control cam  20  can be achieved, even if the distances between the pivot axes  12  of the clamping arm  10  and slotted groove  31 ,  31 ′ differ with respect to the two clamping arms  10 ,  10 ′. The above-mentioned distances  320 ,  320 ′ are in one or more embodiments selected such that the translational ratio provided by the first pair of the first slotted groove and first control bolt corresponds substantially to the translational ratio provided by the second pair of second slotted groove and second control bolt. 
     The centre longitudinal axes  325 ,  325 ′ are the centre axes relative to the cylindrical side wall of the respective control bolt  32 ,  32 ′. The cylindrical side wall or, synonymously, the casing surface corresponds to an arcuate portion  321  of the control bolt  32 ,  32 ′ extending along the entire circumference. 
     In the state arranged on the clamping device  1 , the control cam  20  may be pivoted about its control cam pivot axis  21  between a predefined open position and a predefined closed position by pivoting about said control cam pivot axis  21 . 
     In order to fix the control cam  20 , axially relative to the control cam pivot axis  21 , in a fixed position in the clamping device, the control cam  20  optionally comprises a radial locking groove  327  for receiving a fixing element, e.g. a fitting key or a locking plate, which is in some embodiments arranged on the carrier plate  2  of the clamping device  1 . 
     In order to be able to change the position of the control cam  20  when the clamping device  1  is installed on a container transport device of a container treatment device, said control cam has an interaction part  22  which extends radially outward relative to the control cam pivot axis  21 , and on which for example an interaction bolt, provided at a fixed position of the container treatment device, can stop and thus cause a pivoting of the control cam  20 . 
     In order to limit the movement scope of the control cam  20  about the control cam pivot axis  21 , the interaction part  22  may be configured to cooperate with an optional stop of the clamping device in various embodiments arranged on the carrier plate  2 . In an exemplary embodiment, the control cam  20  to this end comprises two arms  24  which extend radially outward relative to the control cam pivot axis  21  when viewed in the circumferential direction, and which are in some embodiments configured to stop on the stop arranged between the arms  24 , or two stops arranged radially outside the arms  24 , in an end position. Thus, in the state installed in the clamping device  1 , the control cam  20  can pivot about the control cam pivot axis  21  only through an angle  23  delimited by the arms  24 , in particular by the interaction with the at least one stop  3 , which angle in this case is 45°. The end positions of the control cam  20 , at which one of the arms  24  of the control cam  20  lies on the stop  3 , here constitute predefined positions with respect to the open and closed positions of the holding portions of the clamping arms  10  of the clamping device  1 . One end position accordingly constitutes a predefined open position, and the other end position constitutes a predefined closed position. 
     The control cam  20  furthermore comprises a pretension element, in the present case in the form of an elastic spring element  41 , which is configured to interact with a stop element of the clamping device  1  so that the control cam  20  is pretensioned in the predefined open position when the control cam  20  is in the predefined open position, and is pretensioned in the predefined closed position when the control cam  20  is in the predefined closed position. 
     The control cam  20  is in one embodiment configured as one piece, or integrally. The control cam  20  is in some embodiments made from a metal, for example a steel alloy. Alternatively, the control cam may be made from in certain embodiments a polyoxymethylene (POM), and/or parts of the control cam  20 , for example the control bolt  32 , the slotted grooves  31  and/or the shaft portion  26 , may be provided with a coating, in some embodiments a slide coating and/or a wear coating. In several embodiments, the control cam  20  is made from a material different from the carrier plate  2  and/or the clamping arms  10 , for example a metal with a different hardness, or a plastic. 
     The arms  24  and the control bolts  32 ,  32 ′ are configured such that a lever arm ratio between a lever arm present between the control cam pivot axis  21  and a predefined attack point for an interaction element of the container treatment device for switching the control cam  20 , and the lever arms present between the control bolts  32 ,  32 ′ and the control cam pivot axis  21 , lies substantially between 5:1 and 3:1, and in certain embodiments is substantially 4:1. The term “substantially” here means that differences resulting from the different distances  320 ,  320 ′ lie within the rounding or tolerance of the lever arm ratio. In other words, the difference between distances  320 ,  320 ′ is sufficiently small that the resulting differences from the above-described lever arms may be ignored. 
     As described in more detail below with reference to  FIGS.  26  and  27   , each of the coupling elements of the control cam  20 , here in the form of control bolts  32 ,  32 ′, for achieving the permanent forced guidance of the control arms  10  by the control cam  20  provided via the coupling of the coupling elements of the control cam  20  with the clamping arms  10 , in each case comprises a first coupling face  36  extending in the direction of the control cam pivot axis  21  and designed and configured for transmitting a first switching force to the clamping arms  10 , and a second coupling face  36  different from the first coupling face  36 , extending in the direction of the control cam pivot axis  21  and designed and configured for transmitting a second switching force, opposite the first switching force, onto the clamping arm  10  (for details, see  FIGS.  26  and  27   ). 
       FIG.  2    shows schematically a perspective side view of a control cam  20  according to a further embodiment, which substantially corresponds to that of  FIG.  1   . Only the control bolts  32 ,  32 ′ and the interaction part  22 , and the arms  24 , have a different orientation to one another. 
     The orientation of the coupling elements—in  FIGS.  1  and  2   , the control bolts  32 ,  32 ′—with respect to the interaction part  22  or the arms  24  is in some embodiments predefined such that in a predefined closed position, the control bolts  32 ,  32 ′ are oriented perpendicularly to a plane defined by the pivot axes of the clamping arms (see also  FIG.  11   ) or parallel to this plane (see also  FIG.  12   ). 
       FIG.  3    shows schematically a perspective side view of a control cam  20  according to a further embodiment. This substantially corresponds to that of  FIG.  1   . In contrast to the embodiment of  FIG.  1   , in the embodiment of  FIG.  3   , the control bolts  32 ,  32 ′ are connected by a connecting wall  324  which may be understood as two interconnected cam portions  322 . In addition or alternatively to the optional stop  3  (see  FIG.  10   ), the movement of the control cam  20  about the control cam pivot axis  21  may thereby be limited. Since the control bolts  32 ,  32 ′ are connected via the connecting wall  324 , with respect to the control cam pivot axis  21 , they have an increased bending stiffness in the radial direction in comparison with the embodiment of  FIG.  1   . 
       FIG.  4    shows schematically a perspective side view of a control cam  20  according to a further embodiment, which substantially corresponds to that of  FIG.  2   . 
     In the clamping device  1  according to  FIG.  4   , in contrast to the embodiment of  FIG.  1   , the control bolts  32 ,  32 ′ each have a cam portion  322 . In addition or alternatively to the optional stop  3  (see  FIG.  10   ), the movement of the control cam  20  about the control cam pivot axis  21  may thereby be limited. 
     Furthermore, at its free end face opposite the end face  27  viewed in the direction of the control cam pivot axis  21 , the control bolt  32  has a locking web  323 , in this case configured as a circular flange which is arranged concentrically to the longitudinal centre axis  325  of the control  32  and the outer diameter of which is greater than the radius of the arcuate portion  321 , and furthermore greater than the width of the slotted groove  31  transversely to its longitudinal extent  310  (see also  FIG.  15   ). Thus in the direction of the control cam pivot axis  21 , a form fit is created between the clamping arm  10  and the control cam  20  so that in the state shown in  FIG.  15   , not arranged on a container transport device, the control cam  20  is held on the clamping arm  10 . 
     Accordingly, with the control cam  20  shown in  FIG.  4   , no locking groove  327  is required (see  FIGS.  1 - 3   ), so this has been omitted here. 
       FIG.  5    shows schematically a top view of the control cam  20  from  FIG.  4   , with reference to which the pretension element is described in more detail, wherein as already stated with respect to  FIG.  1   , in this embodiment the pretension element takes the form of a spring element  41 , in the present case a curved leaf spring which extends between the arms  24  substantially in the circumferential direction with respect to the control cam pivot axis  21 . As shown in  FIG.  5   , on its radially outer side, the spring element  41  has a curvature indicated by the curvature radius  410  which is greater than a curvature, indicated by the radius  450 , of a geometric pitch circle  45  present concentrically to the control cam pivot axis  21 , at the level of the connecting points of the spring element  41  to the arms  24  of the interaction part  22 . 
     The interaction of the pretension element with the stop  3  of the clamping device  1  is described in more detail below with reference to  FIGS.  16  and  17   . 
     Reference symbol  25  indicates the extent angle of the interaction portion  22  or the arms  24  in the circumferential direction relative to the control cam pivot axis  21 , which angle in this case is 45°. 
       FIG.  6    shows schematically a perspective side view of a control cam  20  according to a further embodiment, which substantially corresponds to the embodiment of  FIG.  3   , wherein the control bolt  32  furthermore comprises a locking web  323  according to  FIG.  4    and accordingly no radial locking groove is provided. 
       FIG.  7    shows schematically a perspective side view of a control cam  20  according to a further embodiment, which is illustrated schematically in a top view in  FIG.  8   . The control cam  20  corresponds substantially to that in  FIG.  2   , wherein the control bolts  32 ,  32 ′ each comprise a cam portion  322  in addition to their arcuate portion  321 . Furthermore, the control cam  20  has a pretension element which differs from the embodiments of  FIGS.  1  to  6   . 
     Instead of the continuous leaf spring which is attached to or transforms into the arms  24  at both ends, the control cam  20  in this embodiment comprises a pretension element which is formed from a web  46  extending substantially centrally between the arms  24  radially outward to the pitch circle  45 , and spring elements  41  which at the radially outer end of the web  46  extend substantially in the circumferential direction or tangentially with respect to the control cam pivot axis  21 , on both sides of the web  46 , in the form of a bending bar with free end, wherein the free end in each case ends at a predefined distance from the respective arm  24 . 
     The spring element  41  have a curvature which is smaller than the curvature of the pitch circle  45 . In other words, the curvature radius  410  of the spring element  41  relative to the control cam pivot axis  21  is greater than the radius  450  of the pitch circle  45 , at the level of which the web  46  ends. 
     Accordingly, the free ends  411  lie radially further out than the pitch circle  45  with respect to the control cam pivot axis  21 . 
     Because there is a distance on both sides of the web  46  between the free end  411  there and the respective arm  24 , a receiver  49  is formed for receiving by form fit, viewed in the circumferential direction relative to the control cam pivot axis  21 , a running roller  42  of the clamping device  1  in the respective end position (see also  FIG.  18   ). 
     The spring elements  41  are here configured such that they are elastically bent by a predefined amount by the running roller  42  situated in the receiver  49 . In this way, they provide a pretension force on the running roller  42  which pretensions the running roller  42  and hence the control cam  20  into the respective end position. 
       FIG.  9    shows schematically a further embodiment of a control cam  20  which corresponds substantially to that of  FIGS.  7  and  8   , wherein here the pretension element is configured as a magnetic pretension element. 
     The magnetic pretension element comprises two magnetic elements  51  arranged one in each of the arms  24 . 
     The magnetic elements  51  are designed and arranged such that, in a state of the control cam  20  installed in the clamping device  1 , they cooperate with a magnet  50  of the stop  3  of the clamping device  1  (see also  FIG.  21   ) such that a magnetic attraction force is present between the magnet  50  and the respective magnetic element  51  when the control cam  20  is in one of the end positions. 
     Instead of the magnetic element  51 , magnetisable or ferromagnetic bodies may be provided in the arms  24 , or the arms  24  themselves may comprise a magnetisable or ferromagnetic material. It is furthermore possible to replace the magnets  50  with a magnetisable or ferromagnetic material, insofar as magnetic elements  51  generating a magnetic field are present in the arms  24 . 
     Furthermore, in some embodiments, a circle segment-shaped connecting bar  28  extends between the arms  24 . This may be designed, like the arms  24 , to cooperate with a magnet  50  of the stop  3 , such that a magnetic attraction force is present between the connecting bar  28 , at least a magnetisable or ferromagnetic body or magnetic element (not shown) provided in the connecting bar  28 , and the stop  3 . The control cam  20  in the clamping device  1  may thus be held at a fixed position axially relative to the control cam pivot axis  21 , without the need for form-fit elements such as the locking groove  327  or locking web  323 . 
       FIG.  10    shows schematically a perspective side view of a clamping device  1  for holding a beverage container at a neck portion. The clamping device comprises two clamping arms  10 ,  10 ′ with a holding portion  11  for holding the container to be held. The holding portion  11  is configured for example to grip a container to be held below a neck ring of the container. The clamping arms  10 ,  10 ′ are arranged on a carrier plate  2  so as to be pivotable about a respective pivot axis  12  for opening and closing. The pivot axes  12  are oriented parallel to one another. 
     The clamping device  1  furthermore comprises a control cam  20  according to  FIG.  1    which is pivotable about a control cam pivot axis  21  oriented parallel to the pivot axes  12 . To predefine the position of the holding portions  11  of the clamping arms  10 ,  10 ′, the clamping arms  10 ,  10 ′ and the control cam  20  are coupled, in the present case via a coupling mechanism  30  described in more detail below. Because of the coupling, a pivoting of the control cam  20  about its control cam pivot axis  21  causes a pivoting of the clamping arms  10  about their pivot axes  12 , so that the holding portions  11  can be moved relative to one another, towards one another or away from one another, in order to open and close the clamping device  1 . In other words, the relative movement of the holding portions  11  is controlled by the control cam  20 . 
     In the present case, the coupling mechanism  30  is formed from or comprises two pairs of a respective slotted groove  31 ,  31 ′ and the control bolt  32 ,  32 ′ guided in the slotted groove  31 ,  31 ′, wherein a respective pair of slotted groove  31 ,  31 ′ and control bolt  32 ,  32 ′ couples a clamping arm  10 ,  10 ′ to the control cam  20 . 
     In the present case, this coupling is provided in that each clamping arm  10 ,  10 ′ has a coupling element in the form of a slotted groove  31 ,  31 ′, in which the control bolt  32 ,  32 ′ assigned to said slotted groove  31 ,  31 ′ and arranged on the control cam  20  is guided, which bolt constitutes a coupling element of the control cam  20  corresponding to the coupling element of the clamping arm  10 ,  10 ′. 
     The “guiding” of the control bolt  32 ,  32 ′ in the assigned slotted groove  31 ,  31 ′ is configured such that the control bolt  32 ,  32 ′ can move translationally relative to the slotted groove  31 ,  31 ′ in a plane extending parallel to the control cam pivot axis  21 , and can roll and/or slide along the side walls of the slotted groove  31 ,  31 ′, or also move rotationally relative to the slotted groove  31 ,  31 ′. 
     The slotted grooves  31 ,  31 ′ each extend completely through the clamping arm  10 ,  10 ′ in the direction of the control cam pivot axis  21 . They may also be regarded as continuous holes in slot form. 
     Viewed in the direction of the control cam pivot axis  21 , the slotted grooves  31 ,  31 ′ each have substantially the form of a slot. Accordingly, in a longitudinal extent  310  oriented perpendicularly to the control cam pivot axis  21 , they extend from a first end  312  to a second end  312 , with side walls  311  running substantially parallel to one another between the two ends  312 . 
     In the present case, the slotted grooves  31 ,  31 ′ are each formed open at one end. In other words, one of the two ends  312  is an open end. In the present case, the open end  312  of each slotted groove  31 ,  31 ′ is the end  312  lying closer to the control cam pivot axis  21 . 
     In order to be able to change the position of the control cam  20  when installed on a container transport device of a container treatment device, said control cam has an interaction part  22  which extends radially outward relative to the control cam pivot axis  21 , and on which for example an interaction bolt, provided at a fixed position of the container treatment device, can stop and thus cause a pivoting of the control cam  20 . 
     In order to limit the scope of movement of the control cam  20  about the control cam pivot axis  21 , the clamping device  1  furthermore comprises an optional stop  3  which is arranged on the carrier plate  2  and which, viewed in the circumferential direction relative to the control cam pivot axis  21 , is arranged between two radially outwardly extending arms  24  of the control cam  20 . Thus the control cam  20  can pivot about the control cam pivot axis  21  only through an angle  23  delimited by the arms  24 , in the present case 45°. The end positions of the control cam, at which one of the arms  24  of the control cam  20  lies on the stop  3 , here constitute predefined positions with respect to the open and closed positions of the holding portions  11 . One end position accordingly constitutes a predefined open position, and the other end position constitutes a predefined closed position. 
     The holding portions  11  may accordingly be moved by pivoting of the control cam  20  between a closed position predefined by the predefined closed position, shown in  FIG.  1   , and an open position predefined by the predefined open position. 
     The clamping device  1  furthermore comprises a pretension device  40  holding or pretensioning the control cam  21  in a predefined position, in the predefined closed position or predefined open position, as will be explained in more detail below. 
     The arms  24  and the control bolts  32 ,  32 ′ are configured such that a lever arm ratio between a lever arm present between the control cam pivot axis  21  and a predefined attack point for an interaction element of the container treatment device for switching the control cam  20 , and the lever arms present between the control bolts  32 ,  32 ′ and the control cam pivot axis  21 , lies substantially between 5:1 and 3:1, and in some embodiments is substantially 4:1. The term “substantially” here means that differences resulting from the different distances  320 ,  320 ′ lie within the rounding or tolerance of the lever arm ratio. In other words, the difference between distances  320 ,  320 ′ is sufficiently small that the resulting differences from the above-described lever arms may be ignored. 
     A sliding plate  4  is provided between the carrier plate  2  and the clamping arms  10 , and provides a slide bearing of the clamping arms  10  relative to the carrier plate  2 . 
     Furthermore, a sliding plate  4  is provided above the clamping arms  10  and provides a slide bearing of the clamping arms  10  relative to a container transport device on which the clamping device  1  may be arranged. 
     The clamping arms  10  and/or the carrier plate  2  may be made of a metal, for example a steel alloy. In some embodiments, the sliding plates  4  are made from a material different from the carrier plate  2  and/or the clamping arms  10 , for example a plastic, a copper alloy or a brass alloy. 
       FIG.  11    shows schematically a top view of a clamping device  1  according to a further embodiment. The clamping device  1  shown in  FIG.  11    nonetheless substantially corresponds to that of  FIG.  10   . 
     In particular, a common factor of the embodiments of  FIGS.  10  and  11    is that the clamping arms  10 ,  10 ′ are not formed symmetrically, in particular with respect to the region around the slotted grooves  31 ,  31 ′. Thus a particularly compact construction of the clamping device  1  may be achieved. In this respect, the slotted groove  31  arranged on the clamping arm  10  has a first distance from the pivot axis  12  of the clamping arm  10 , and the slotted groove  31 ′ arranged on the clamping arm  10 ′ has a second distance from the pivot axis  12 ′ of the clamping arm  10 ′, wherein the amount of the second distance is greater than the amount of the first distance. The distances correspond to the length of the lever arms. 
     So that on pivoting of the control cam  20 , the two clamping arms  10 ,  10 ′ each pivot through the same angle about their respective pivot axis  12 ,  12 ′, or in other words pivot symmetrically relative to one another, the control bolt  32  guided in the slotted groove  10  is arranged on the control cam  20  at a first distance  320  from the control cam pivot axis  21  which is smaller than the distance of the second control bolt  32 ′ guided in the slotted groove  31 ′ from the control cam pivot axis  21 . The above-mentioned distances are selected such that the translational ratio provided by the first pair of the slotted groove  31  and control bolt  32  corresponds substantially to the translational ratio provided by the pair of slotted groove  31 ′ and control bolt  32 ′. 
     In the closed position of the holding portions  11  shown in  FIGS.  10  and  11    respectively, the control cam  20  is present in the predefined closed position. The control bolts  32 ,  32 ′ are here arranged on the control cam  20  such that in the predefined closed position of the control cam  20 , viewed in the direction of the control cam pivot axis  21 , they lie on a line which is oriented perpendicularly to a plane  35  formed by the two pivot axes  12 ,  12 ′. 
     In contrast to the embodiment of  FIG.  10   , in the embodiment of  FIG.  11   , the control bolts  32 ′ are connected by a connecting wall  324 , which may be understood as two interconnected cam portions  322 . Firstly, in addition or alternatively to the optional stop  3  (see  FIG.  1   ), the movement of the control cam  20  about the control cam pivot axis  21  may thereby be limited. Since the control bolts  32 ,  32 ′ are connected via the connecting wall  324 , with respect to the control cam pivot axis  21 , they have an increased bending stiffness in the radial direction in comparison with the embodiment of  FIG.  1   . 
       FIG.  12    shows schematically a top view of the clamping device  1  from  FIG.  11    in an open position in which the holding portions  11  are in their open position. Accordingly, the control cam  20  is pivoted through the predefined angle  23 , in this case 45°, relative to its orientation in  FIG.  11   . Via the coupling of the control cam  20  to the clamping arms  10 ,  10 ′, which is provided by means of the above-described coupling mechanism  30  and which may be regarded as the forced guidance of the coupling arms  10 ,  10 ′ by the control cam  20 , accordingly the coupling arms  10 ,  10 ′ are also pivoted about their pivot axes  12 ,  12 ′. 
     On pivoting of the control cam  20  between the predefined open position and the predefined closed position, the control bolts  32 ,  32 ′ move along their assigned slotted grooves  31 ,  31 ′. Viewed relative to the slotted grooves  31 ,  31 ′, this movement of the control bolts  32 ,  32 ′ constitutes a translational movement component along the longitudinal extent  310  of the slotted grooves  31 ,  31 ′ and a rotational movement component or a slide movement relative to the side walls  311  of the slotted grooves  31 ,  31 ′. 
     In order to allow the latter rotational movement component, the control bolts  32 ,  32 ′ have a portion which is curved relative to the respective longitudinal centre axis  325 , in this case in the form of an arcuate portion  321 . In contrast to the embodiment of  FIG.  1   , in which the arcuate portion  321  runs over the entire circumference of the cylindrical control bolts  32 ,  32 ′, the arcuate portion  321  in the embodiment of  FIGS.  2  and  3    is delimited by the connecting wall  324 . 
       FIGS.  13  and  14    each show schematically a top view of a clamping device  1  according to a further embodiment, in a closed position ( FIG.  13   ) and an open position ( FIG.  14   ). The clamping device  1  substantially corresponds to the clamping device  1  from  FIG.  10   . 
     In contrast to the clamping devices  1  from  FIG.  10    and  FIGS.  11  and  12   , the clamping device  1  in  FIGS.  13  and  14    has a structure such that in the closed position of the clamping device  1 , or when the holding portions  11  are in their closed position and accordingly the control cam  20  is in the predefined closed position, the control bolts  32 ,  32 ′, viewed perpendicularly to the control cam pivot axis  21 , lie on a line  34  which lies substantially parallel to the plane  35  formed by the pivot axes  12 ,  12 ′. In this embodiment, the holding portions  11  can particularly effectively be prevented from opening under a pivoting of the clamping arms  10 ,  10 ′ about their pivot axes  12 ,  12 ′ by a pressure against the holding portions  11 , for example because of a sudden impact on a container held in the clamping device  1 . 
       FIG.  15    shows schematically a perspective side view of a clamping device  1  according to a further embodiment, which substantially corresponds to that of  FIG.  10   . 
     The clamping device  1  according to  FIG.  15   , in contrast to the embodiment of  FIG.  10   , has the control bolts from  FIG.  4   . 
     The locking web  323  is formed as described above by a circular flange which is arranged concentrically to the longitudinal centre axis  325  of the control bolt  32 , and the outer diameter of which is greater than the width of the slotted groove  31  transversely to its longitudinal extent  310 . Thus in the direction of the control cam pivot axis  21 , a form fit is created between the clamping arm  10  and the control cam  20  so that in the state shown in  FIG.  15   , not arranged on a container transport device, the control cam  20  is held on the clamping arm  10 . 
     With reference to  FIGS.  16  and  17   , the pretension device  40  which is common to  FIGS.  10  to  15    is now described in more detail. 
       FIG.  16    shows schematically a view from below of the clamping device  1  from  FIG.  10   , and  FIG.  17    shows schematically a perspective side view from below of a part region of the clamping device  1  from  FIG.  10   . 
     The pretension device  40  is configured to hold or pretension the control cam  20  in a predefined end position, either the predefined open position or the predefined closed position. 
     In the embodiment as common to the clamping devices  1  from  FIGS.  10  to  17   , the pretension device  40  is provided by the pretension element arranged on the control cam  20 , which according to this embodiment takes the form of the spring element  41 , in the present case a curved leaf spring, and extends between the arms  24  substantially in the circumferential direction relative to the control cam pivot axis  21 . As shown in  FIG.  16   , on its side pointing towards the running roller  42 , the spring element  41  has a curvature, indicated by the curvature radius  410 , which is greater than a curvature, indicated by the radius  450 , of a geometric pitch circle  45  present concentrically to the control cam pivot axis  21 , at the level of the connecting points of the spring element  41  to the arms  24  of the interaction part  22 . 
     As evident in particular from  FIG.  17   , the stop  3  is formed by a running roller  42  which is mounted rotatably on the carrier plate  2  via a bearing bolt  48 , and which is in contact with or rolls over the spring element  41 , limited by the arms  24  providing the end positions. 
     Since the spring element  41  curves radially outward relative to the pitch circle diameter  45  with respect to the control cam pivot axis  21 , because of the smaller curvature radius  410  in comparison with radius  450 , the spring element  41  exerts a spring force on the running roller  42  which is at its largest in the middle of the spring element  41 , and thereby pretensions the running roller  42  into the respective end position. Because of this pretension, the control cam  20  and accordingly the clamping arms  10  are in a stable state, namely either in the open position or in the closed position. 
     In order to move the clamping arms  10  out of the respective position, the control cam  20  must be moved against the tension provided by the spring element  41 . In other words, the force occurring from the spring force of the spring element  41  generated during rolling of the running roller  42  over the spring element  41  because of the resulting elastic bending, must be overcome in order to allow a relative movement of the running roller  42  and control cam  20 . When the apex or middle of the spring element  41  is passed, the spring force provided by the spring element  41  because of its bend supports the movement of the control cam  20  into the respective end position. 
     The stop  3 , here in the form of the running roller  42  mounted on the carrier plate  2 , is also the stop element which is configured to interact with the pretension element of the control cam  20 , provided in this case as a spring element  41 , such that the control cam  20  is pretensioned into the predefined open position when the control cam  20  is in the predefined open position, and is pretensioned in the predefined closed position when the control cam  20  is in the predefined closed position. 
     Reference symbol  25  indicates the extent angle of the interaction portion  22  or the arms  24  in the circumferential direction relative to the control cam pivot axis  21 , which angle in this case is 45°. 
     As shown in  FIG.  17   , the running roller  42  is mounted on the bearing bolt  48  eccentrically to a bearing bolt  48  arranged rotationally fixedly on the carrier plate  2 . Accordingly, the rotational axis  43  of the running roller  42  has a predefined distance from the bearing centre axis  44  of the bearing bolt  48 . 
     By twisting the orientation of the bearing bolt  48  about its longitudinal centre axis  44 , a pretension force provided by the spring element  41  can be changed. Accordingly, thus also a holding force of the clamping arms in the respective end position, here the closed position, when the control cam  20  is in the predefined closed position, can be adjusted. 
     In an alternative embodiment, the bearing bolt  48  may be pretensioned in the circumferential direction relative to the bearing centre axis  44 , such that the running roller  42  is pressed in the radial direction relative to the control cam pivot axis  21  onto the control cam  20 , in some embodiments in that a torsion spring (not shown here) is provided between the carrier plate  2  and the bearing bolt  48 . 
     If, in this embodiment, the spring element  41  is also provided, the pretension force which holds the control cam  20  in one of the end positions consists of the spring force on the side of the running roller  42  together with the spring force on the side of the spring element  41 . 
     Alternatively, with such a sprung mounting of the running roller  42 , which is rotationally mounted eccentrically to the bearing centre axis  44 , instead of the elastic spring element  41 , a rigid element may be provided which, like the spring element  41 , has a curvature greater than that of the pitch circle  45 . Then the pretension force for holding the control cam  20  in one of the end positions is provided solely by the spring element (not shown) on the side of the running roller  42 . 
     The shape of the arms  24  and the position of the running roller  42  are predefined such that a lever arm ratio between a lever arm present between the control cam pivot axis  21  and the contact region of the running roller  42  on the arms  24 , and the lever arms present between the control bolts  32 ,  32 ′ and the control cam pivot axis  21 , lies substantially between 6:1 and 2:1, and is in various embodiments substantially 5:1, 4:1 or 3:1. The term “substantially” here means that differences resulting from the different distances  320 ,  320 ′ lie within the rounding or tolerance of the lever arm ratio. In other words, the difference between distances  320 ,  320 ′ is sufficiently small that the resulting differences from the prescribed lever arms may be ignored. 
       FIG.  18    shows schematically a view from below of a clamping device  1  according to a further embodiment. The clamping device  1  substantially corresponds to that of  FIG.  17    with the exception of the design of the pretension device  40 . Instead of the continuous leaf spring which is attached to the arms  24  at both ends or transforms into these, in this embodiment, the control cam  20  corresponding to the embodiment of  FIGS.  7  and  8    comprises a pretension element which is formed from a web  46  extending substantially centrally between the arms  24  radially outwardly to the pitch circle  45 , and spring elements  41  which extend at the radially outer end of the web  46  substantially in the circumferential direction or tangentially with respect to the control cam pivot axis  21 , on both sides of the web  46 , in the form of a bending bar with free end, wherein the free end in each case ends at a predefined distance from the respective arm  24 . 
     The spring elements  41  have, as described above, a curvature which is smaller than the curvature of the pitch circle  45 . In other words, the curvature radius  410  of the spring element  41  relative to the control cam pivot axis  21  is greater than the radius  450  of the pitch circle  45 , at the level of which the web  46  ends. 
     Accordingly, the free ends  411  lie radially further out than the pitch circle  45  with respect to the control cam pivot axis  21 . The running roller  42  forming the stop element is in this case mounted such that if theoretically the web  46  were omitted, it would roll on the pitch circle  45 . 
     Because there is a distance on both sides of the web  46  between the free end  411  there and the respective arm  24 , a receiver  49  is formed for receiving by form fit, viewed in the circumferential direction relative to the control cam pivot axis  21 , a running roller  42  in the respective end position. 
     The spring elements  41  are here configured such that they are elastically bent by a predefined amount by the running roller  42  situated in the receiver  49 . In this way, they provide a pretension force on the running roller  42  which pretensions the running roller  42  into the respective end position. 
     In order to move the running roller  42  out of the respective position, the control cam  20  must be moved against the pretension provided by the spring element  41 . This embodiment provides a particularly secure holding of the running roller  42  or the control cam  20  in one of the end positions, since the pretension force provided by the spring element  41  on the running roller  42  is greatest in the end positions. 
     Optionally, as in the embodiment of  FIG.  17   , the running roller  42  may be mounted eccentrically to the bearing centre axis  44  and/or pretensioned against the control cam. 
       FIG.  19    shows schematically a view from below of a clamping device  1  according to a further embodiment. The clamping device  1  substantially corresponds to that of  FIG.  17    with the exception of the design of the pretension device  40 . Instead of the spring element  41  provided as a continuous leaf spring, a bolt  47  providing the pretension element is spring-mounted in the radial direction on the control cam  20 , radially spaced from the control cam pivot axis  21 . Like the embodiment in  FIG.  17   , the bolt  47  has a curvature, indicated by curvature radius  410 , which is greater than the curvature of the pitch circle  45 . Because of its spring-mounting against the running roller  42 , the bolt  47  is pretensioned towards the outside in the radial direction. Accordingly, the running roller  42  is held in one of the end positions by the bolt  47 . 
     Optionally, as in the embodiment of  FIG.  17   , the running roller  42  functioning as a stop element may be mounted eccentrically to the bearing centre axis  44  and/or pretensioned against the control cam. 
       FIG.  20    shows schematically a perspective side view of a clamping device  1  according to a further embodiment, which substantially corresponds to that of  FIG.  18   . 
     In this embodiment, like the embodiment of  FIG.  10   , the control bolts  32  are configured as a cylindrical pins extending parallel to the control cam pivot axis  21 . At their ends above the clamping arms  10 , these are connected via a locking web  323  which extends between the two control bolts  32 . 
     The functionality of the locking web  323  corresponds to that described with reference to  FIG.  15   . In addition, in comparison with the embodiment in  FIG.  10   , it provides an increased bending stiffness of the control bolt  32  in the radial direction relative to the control cam pivot axis  21 . 
       FIG.  21    shows schematically a perspective side view of a clamping device  1  according to a further embodiment, which substantially corresponds to that of  FIG.  10   . 
     The control bolts  32  in this embodiment, in contrast to the embodiment of  FIG.  10   , each have a cam portion  322  as already described with reference to the control bolt  32 ′ from  FIG.  15   . 
     Furthermore, the pretension device  40  is configured as a magnetic pretension device  40 . To this end, the stop  3  functioning as a stop element has a magnet  50  which cooperates with a magnetic element  51  of the control cam  20 , configured similarly to  FIG.  9   , which is provided in each of the arms  24 , such that a magnetic attraction force is present between the magnet  50  and the respective magnetic element  51  when the control cam  20  is in one of the end positions. The magnetic attraction force holds the control cam  20  in the respective end position. In order to move the control cam  20  out of the respective end position, the magnetic attraction force must be overcome. The magnetic elements  51  arranged in the arms  24  also form the pretension element of the control cam, which is configured to cooperate with the stop  3  functioning as the stop element, or more precisely its magnet  50 , such that the control cam  20  is pretensioned in the predefined open position when the control cam  20  is in the predefined open position, and is pretensioned in the predefined closed position when the control cam  20  is the predefined closed position. 
     Instead of the magnetic element  51 , ferromagnetic bodies may also be provided in the arms  24 . It is furthermore possible to replace the magnets  50  with a ferromagnetic material, insofar as magnetic elements  51  generating a magnetic field are present in the arms  24 . 
       FIG.  22    shows schematically a top view of a clamping device  1  according to a further embodiment, which substantially corresponds to that of  FIG.  10   , wherein the pretension device  40  is a magnetic pretension device according to  FIG.  21   . 
     The coupling mechanism  30  differs in that the control bolts  32  are provided on the clamping arms  10 . They extend from a side of the clamping arms  10  to be regarded as the underside  22 , which constitutes a side of the clamping arms  10  pointing in the direction of the control cam  20 , parallel to the control cam pivot axis  21  with a predefined length in the direction of the control cam  20 . 
     Each of the control bolts  32  is guided into a blind hole-like slotted groove  31  functioning as a coupling element of the control cam  20  and provided on an end face  27  pointing in the direction of the clamping arms  10 , in  FIG.  22    the top side of the control cam  20 . 
     The control bolts  32  are each arranged on their clamping arm  10  at a distance or with a radius  326  away from the pivot axis  12  of the respective clamping arm  10 . In other words, they pivot about the respective pivot axis  12  on the radius  326 . 
       FIGS.  23  and  24    show schematically a top view and a side view of an upper part of a control cam  20 , similarly to the embodiment in  FIG.  22   , wherein in this embodiment the slotted grooves  31  are formed open at one end. In other words, the ends  312 ′ located radially on the outside with respect to the control cam pivot axis  21 , are configured as free or open ends  312 ′. Thus for example a cleaning fluid, which enters the slotted grooves  31  during cleaning of a container treatment device comprising the clamping device  1 , can flow out of the slotted grooves  31  again at the open ends  312 ′. 
       FIG.  24    shows the design of the slotted grooves  31  as blind holes. The slotted grooves  31  extend with a predefined depth into the control cam  20  from the end face  27  parallel to the control cam pivot axis  21 . 
       FIG.  25    shows schematically a clamping device  1  according to a further embodiment. The clamping device  1  substantially corresponds to that of  FIG.  10    with the following differences: 
     The coupling mechanism  30  comprises precisely one pair of slotted groove  31  and control bolt  32 . Here, the pair of slotted groove  31  and control bolt  32  couples one of the clamping arms  10  directly to the control cam  20 . This clamping arm  10  is furthermore rotationally coupled to the other clamping arm  10 ′ via a gear mechanism  60 . 
     In other words, the coupling mechanism  30  in this embodiment comprises the precisely one pair of slotted groove  31  and control bolt  32 , for moving the first clamping arm  10  via a movement of the control cam  20 , and furthermore the coupling mechanism  30  comprises a rotational coupling unit, in the present case in the form of the gear mechanism  60 , for coupling the first clamping arm  10  to the second clamping arm  10 ′ in order thus to provide an indirect coupling, via the clamping arm  10 , of the second clamping arm  10 ′ to the control cam  20 . 
     Accordingly, the control cam  20  has precisely one coupling element, here in the form of the control bolt  32 . Alternatively, the control cam  20  could also have a slotted groove similar to that of  FIGS.  22  to  24   , in which a control bolt  32  arranged on one of the clamping arms  10  is then received as described above, in order to provide the coupling between the control cam  20  and the one clamping arm  10 . 
     Both clamping arms  10 ,  10 ′ have a toothing portion  61  in the form of a gear wheel which is arranged substantially concentrically to the pivot axis  12  of the respective clamping arm  10 ,  10 ′ and extends perpendicularly thereto. The toothing portions  61  are in engagement with one another, thereby forming the rotational coupling between the clamping arms  10 ,  10 ′. 
     The control bolt  32  furthermore comprises a locking web  323 , similarly to the embodiment of  FIG.  15   . 
       FIG.  26    shows schematically a top view, in the direction of the control cam pivot axis  21 , of a detail of the control cam  20  of the clamping device  1  from  FIG.  13   , wherein for the sake of greater clarity only one of the two control bolts  32  shown. The description below relating to the control bolt  32  also applies to the second control bolt  32 ′, which is not shown here for reasons of clarity. 
     As evident from  FIG.  13   , in  FIG.  26    the control cam is positioned in the predefined closed position. Accordingly, it pretensions the clamping arms  10 ,  10 ′ in the closed position. For this, the control bolt  32 , at its contact point with the side wall  311 ′ of the slotted groove  31  (here indicated by dotted lines) of the clamping arm  10 , transmits a force  37 ′ provided by the pretension device  40  to the clamping arms  10 . This force  37 ′ may be regarded as a closing force  37 ′, since this presses the clamping arms  10  into the closed position or holds them in the closed position. The above-mentioned actual contact point of the control bolt  20  may be regarded as a first coupling face border point  37 . 
     When a switching process is initiated in which the control cam  20  is pivoted out of its predefined closed position, shown in  FIG.  26   , through the angle  23  into the predefined open position, shown in  FIG.  27   , the control cam  20 , on initiation of the switching process in a pivot direction  13 , when the control cam  20  is still substantially in the closed position—apart from a play present between the slotted groove  31  and control cam  32 —comes into contact with the (second) side wall  311  of the slotted groove  31  opposite the (first) side wall  311 ′ of the slotted groove  31 , and with the (second) side wall  311  forms a contact point similarly to the above-mentioned contact point. This initial contact point with the side wall  311  may be regarded as a first coupling face border point  37  of the control bolt  32 . The control cam now exerts a switching force  16 , here accordingly an opening force, on the clamping arm  10  which causes a pivoting of the clamping arm  10  out of the closed position. 
     The term “coupling face border point” is not restricted to a point in the geometric sense but comprises contact types generally known to the person skilled in the art, such as spot contact, line contact and superficial contact. For example, in each case a side wall of the cam portion  322  of a control bolt  32 , such as shown in  FIG.  7   , forms a coupling face border point in the sense of a superficial contact. 
       FIG.  27    shows schematically a further top view, perpendicularly to the control cam pivot axis  21 , of the detail of the control bolt  32  from  FIG.  26   , wherein the control cam  20  has been pivoted out of the predefined closed position shown in  FIG.  26   , through the angle  23  into the predefined open position, and accordingly is in the predefined open position (see  FIG.  14   ). The predefined closed position is here indicated with reference sign  15 , and the predefined open position  14  with reference sign  14 . During movement out of the predefined closed position to the predefined open position, a part of the arcuate portion  321  of the control bolt  32 , from the first coupling face border point  37  to a second coupling face border point  38 , slides over the side wall  311  of the slotted groove  31  of the clamping arm  10  to be controlled. 
     The control bolt  32  also comprises a first coupling face  36  extending between the first coupling face border point  37  and the second coupling face border point  38 , which is designed and configured to transmit a first switching force  16 , here the opening force, onto the slotted groove  31 , or more precisely its side wall  311  which may be regarded accordingly as the coupling face  39  of the slotted groove  31  for coupling to the coupling face  36 , and if the control cam  20  is pretensioned in the predefined open position, to transmit a pretension force  16  to the clamping arms  10  for pretensioning the clamping arms  10  into the open position. 
     Reference symbol  23 ′ indicates a pivoting of the control cam  20  out of the predefined open position  14  (back) into the predefined closed position  15 . Similarly to the above, on initiation of the pivot process, the control bolt  32  comes into contact with the side wall  311 ′ at a second coupling face border point  38 ′, so that it can transmit a second switching force  16 ′, here a closing force, which is directed opposite the first switching force  16  or the opening force. 
     The term “opposite” here means that the first switching force  16  and the second switching force  16 ′ each have a circumferential component relative to the control cam pivot axis  21 , wherein the circumferential component of the first switching force  16  and the circumferential component of the second switching force  16 ′ are oriented opposite one another or in opposite directions. 
     The control cam  20  also comprises a second coupling face  36 ′ different from the first coupling face  36 . The coupling faces  36 ,  36 ′ are arranged opposite one another with respect to the control bolt  32 , in particular its contour or cross-sectional contour perpendicular to the control cam pivot axis  21 , and/or with respect to the longitudinal centre axis  325 . Thus alternately, the two switching and in several embodiments pretensioning forces  16 ,  16 ′ can be transmitted to the clamping arms  10 ,  10 ′ via the control bolt  32  for switching and/or pretensioning the control cam  20 . 
     Similarly to the above, the coupling faces  39 ,  39 ′ of the slotted groove  31 , which in this optional embodiment substantially correspond to the length of the side walls  311 ,  311 ′, are arranged opposite one another with respect to the slotted groove  31 , in particular its contour or cross-sectional contour perpendicular to the control cam pivot axis  21 , and/or with respect to the longitudinal extent  310 . 
     Because the control bolt  32  has the first coupling face  36  which extends in the direction of the control cam pivot axis  21  and is designed and configured for transmitting the first switching force  16  onto the clamping arm  10 , and the second coupling face  36 ′ which is different from the first coupling face  36  and extends in the direction of the control cam pivot axis  21 , and is designed and configured for transmitting the second switching force  16 ′, directed opposite the first switching force  16 , onto the clamping arm  10 , via the control bolt  32  functioning as a coupling element, a permanent forced guidance of the clamping arms  10 ,  10 ′ can be provided both during opening and during closing, and in certain embodiments also a pretension of the clamping arms  10 ,  10 ′ into the open position or the closed position. 
       FIGS.  28  and  29    shows top views, in the direction of the control cam pivot axis  21 , of a detail of the control cam  20  of the clamping device  1  from  FIG.  22   , wherein the control cam is in the predefined closed position in  FIG.  28    and in the predefined open position in  FIG.  29   . 
     Similarly to the description relating to  FIGS.  26  and  27   , the coupling element of the control cam  20 , here configured as a slotted groove  31 , has a first coupling face  36  which extends between a first coupling face border point  37  and a second coupling face border point  38 , and a second coupling face  36 ′ which extends between a first coupling face border point  37 ′ and a second coupling face border point  38 ′. Also similarly to  FIGS.  26  and  27   , the first coupling face  36  is designed and configured for transmitting to the clamping arm  10  the first switching force  16 , here the opening force and pretension force into the open position. Furthermore, the second coupling face  36 ′, different from the first coupling face  36  and extending in the direction of the control cam pivot axis  21 , is designed and configured for transmitting to the clamping arm  10  the second switching force  16 ′, opposite the first switching force  16 , here the closing force and pretension force into the closed position. 
     Further similarly, the coupling faces  36 ,  36 ′ are arranged opposite one another with respect to the slotted groove  31 , in particular its contour or cross-sectional contour perpendicular to the control cam pivot axis  21 , and/or with respect to the longitudinal extent  310 . Thus the two switching and in some embodiments pretensioning forces  16 ,  16 ′ can be transmitted to the clamping arms  10 ,  10 ′ alternately via the slotted groove  31  for switching and/or pretensioning the control cam  20 . 
     The coupling face  36  corresponds to part of the length of the side wall  311 , and the coupling face  36 ′ corresponds to part of the side wall  311 ′. 
     If applicable, all individual features that are illustrated in the exemplary embodiments may be combined with one another and/or exchanged without departing from the scope.