Patent Publication Number: US-2023159315-A1

Title: Clamping device for holding a container

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority from German Patent Application No. DE 10 2021 131 001.6, 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 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. 
     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 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 here 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, and a control cam which is pivotable about a control cam pivot axis, wherein the clamping arms and the control cam are coupled via a coupling mechanism so that a pivoting of the control cam about its control cam pivot axis causes a pivoting of the clamping arms relative to one another. 
     The coupling mechanism comprises at least one pair of a slotted groove and a control bolt guided in the slotted groove for transmitting movements of the control cam to the clamping arms. 
     In other words, the clamping arms and the control cam are coupled via at least one slotted groove and a control bolt assigned to the slotted groove and guided in the slotted groove for transmitting movements of the control cam to the clamping arms, so that a pivoting of the control cam about its control cam pivot axis causes a pivoting of the clamping arms relative to one another. The above-described coupling may be regarded as a coupling mechanism. 
     Because the coupling mechanism comprises at least one pair of a slotted groove and a control bolt guided in the slotted groove for transmitting movements of the control cam to the clamping arms, a permanent or persistent forced guidance of at least one clamping arm by the control cam can be provided. In other words, because of the coupling (provided by the coupling mechanism), the position and a movement of the clamping arms are always predefined by the position and movement of 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, 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 pair of slotted groove and control bolt, a defined contact of the holding portions on the container to be held may be achieved. 
     A clamping device 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 components of the clamping device. 
     With a container treatment device having the clamping device, 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 in this document describes in particular a fixed pivot axis, i.e. 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. Furthermore, the control cam may for example comprise a shaft portion which is rotatably mounted in a bore in the carrier plate. 
     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, for example 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. 
     According to a one embodiment, the holding portions can be moved into an open position and/or a closed position by the pivoting of the control cam. 
     Furthermore, alternatively or additionally, the clamping arms may be arranged pivotably in a plane oriented perpendicularly to the control cam pivot axis. 
     In various embodiments, the clamping arms are pivotable about at least one axis oriented parallel to the control cam pivot axis, wherein in some embodiments each clamping arm has a respective pivot axis about which it is pivotable. 
     A particularly compact structure and also a favourable force distribution with respect to the forces introduced by the control cam and a force exerted by the holding portions on the container held therein, and with respect to a ratio in relation to a movement scope of the control cam relative to the movement scope of the holding portions, can be achieved if the holding portions are arranged on one side of the clamping arms, and in some embodiments with respect to the at least one pivot axis, and the at least one pair of slotted groove and control bolt is arranged on the other side. 
     According to a further embodiment, the at least one slotted groove is arranged on the clamping arm side and the at least one control bolt is arranged on the control cam. In other words, at least one of the clamping arms may comprise a slotted groove in which the control bolt assigned to said slotted groove and arranged on the control cam is guided. 
     Alternatively or additionally, at least one control bolt may be arranged on the clamping arm side and the at least one slotted groove assigned to said control bolt is arranged on the control cam. In other words, at least one of the clamping arms may comprise a control bolt which is guided in the slotted groove assigned to said control bolt and arranged on the control cam. 
     According to a further embodiment, the coupling mechanism comprises two pairs of slotted groove and control bolt, wherein each pair of slotted groove and control bolt couples a respective clamping arm to the control cam. 
     Alternatively, the coupling mechanism may comprises precisely one pair of slotted groove and control bolt, wherein the pair of slotted groove and control bolt couples one of the clamping arms to the control cam and this clamping arm is rotationally coupled to the other clamping arm, and in certain embodiments via a gear mechanism, for example a toothed gear mechanism. 
     In other words, the coupling mechanism according to the above embodiment comprises the precisely one pair of slotted groove and control bolt, for moving the first clamping arm via a movement of the control cam, and furthermore the coupling mechanism comprises a rotational coupling unit for coupling the first clamping arm to the second clamping arm, which is not itself directly coupled to the control bolt. The rotational coupling unit is in several embodiments formed as a gear mechanism, for example a toothed gear mechanism. Accordingly, the control cam is coupled directly to one clamping arm via the pair of slotted groove and control bolt, and coupled indirectly to the other clamping arm via the directly coupled clamping arm and the rotational coupling unit. 
     Advantageously, both clamping arms have a toothing portion in the form of a gear wheel which is arranged substantially concentrically to the pivot axis of the respective clamping arm and extends perpendicularly thereto. The toothing portions are in engagement with one another, thereby forming the rotational coupling between the clamping arms. 
     It has proved advantageous to arrange at least one control bolt eccentrically relative to the control cam pivot axis. 
     Since the at least one control bolt is arranged eccentrically relative to the control cam pivot axis, said elements are not concentric to one another. Rather, the control cam pivot axis and the at least one control bolt, in particular a longitudinal centre axis of the control bolt, have a distance from one another in a plane oriented perpendicularly to the control cam pivot axis. The distance may be a variable distance, for example if the at least one control bolt is arranged on the clamping arm side, in other words on one of the clamping arms, or in yet other words if one of the clamping arms comprises the control bolt. 
     According to a further embodiment, a first slotted groove is arranged on a first clamping arm and has a first distance from the pivot axis of the first clamping arm, and furthermore a second slotted groove is arranged on the second clamping arm and has a second distance from the pivot axis of the second clamping arm. In one or more embodiments, the amount of the second distance is greater than the amount of the first distance, and furthermore in various embodiments, a first control bolt guided in the first slotted groove is arranged on the control cam with a first distance the control cam pivot axis, and a second control bolt guided in the second slotted groove is arranged on the control cam with a second distance from the control cam pivot axis, the amount of which distance is greater than that of the first distance. Thus a particularly compact construction of the clamping device may be achieved. 
     The above-mentioned distances are in several 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. Then a symmetrical pivoting of the two clamping arms may be achieved. 
     According to a further embodiment, at least one slotted groove is at least partially formed as a continuous bore, and/or at least one slotted groove is at least partially formed as a blind hole bore, and/or at least one slotted groove is formed open at one end, and/or at least one slotted groove is formed open at both ends. 
     According to a further embodiment, the at least one control bolt comprises a portion which is curved, in one embodiment an arcuate portion, relative to a longitudinal centre axis of the control bolt. The control bolt can then carry out a rotational movement in the slotted groove relative thereto, or slide and/or roll on the wall of the slotted groove. 
     Alternatively or in addition, at least one control bolt may have a cam portion which extends in a plane oriented perpendicularly to the control cam pivot axis. Because of the cam portion, a rotational movement of the control bolt relative to the slotted groove may be restricted in its scope to a predefined amount. For example, the control cam may function as a stop for a side wall of the slotted groove. 
     A particularly low-wear operation of the clamping device may be achieved if the clamping arms, the control cam and the coupling mechanism are configured such that by pivoting of the control cam between a predefined open position and a predefined closed position, the holding portions can be moved, by pivoting of the clamping arms relative to one another, into an open position and/or a closed position, wherein the control cam can be moved between the predefined open position and the predefined closed position, relative to a plane perpendicular to the control cam pivot axis, in some embodiments by a predefined pivot angle, wherein the predefined pivot angle lies in a range between 40° and 55° for example between 44° and 50° and in another example is substantially 45°, 46°, 47° or 48°. 
     According to a further embodiment, the clamping device comprises a pretension device which is configured to pretension the control cam into at least one predefined end position which in some embodiments corresponds to the predefined open position and/or the predefined closed position. 
     In certain embodiments, the pretension device comprises at least one spring element arranged on the control cam, and at least one running roller in contact with the spring element, wherein the spring element pretensions the running roller in several embodiments into the at least one end position. 
     According to a further embodiment, 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. 
     Alternatively, the control cam may have a web extending radially outward relative to a geometric pitch circle present concentrically to the control cam pivot axis, from which web a spring element extends tangentially to the radial direction relative to the control cam pivot axis, for example one spring element on each side of the web. With such a structure, the pretension provided by the spring element on the running roller may be greatest in the at least one end position. 
     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 running roller is mounted on the bearing bolt, eccentrically to a bearing centre axis of a bearing bolt arranged rotationally fixedly on a carrier plate, wherein in various embodiments the orientation of the bearing bolt about its bearing centre axis can be changed. Thus the amount of a pretension present between the running roller and spring element may be adjusted. By adjusting the running roller in the direction of the control cam pivot axis, the pretension force may be increased, and by moving it in the other direction, said force may be reduced correspondingly. 
     Additionally or alternatively, the running roller may be pretensioned onto the control cam in the radial direction with respect to the control cam pivot axis. For example, the running roller may be spring-mounted in the direction of the control cam, for example via a torsion spring. 
     According to a further embodiment, the pretension device is configured as a magnetic pretension device, wherein in one or more embodiments a stop arranged on a carrier plate has a magnet or a magnetisable and/or ferromagnetic material which cooperates with at least one magnetic element or magnetisable and/or ferromagnetic material provided in various embodiments on the control cam, on an arm which extends radially outward relative to the control cam pivot axis, such that because of a magnetic attraction force between said elements, the control cam is held in at least one end position. 
     According to a further embodiment, viewed in the direction of the control cam pivot axis, at an end face, the control bolt has a locking web for holding the control cam on at least one clamping arm, wherein the locking web is in one embodiments formed as a circular flange which is in some embodiments arranged concentrically to the longitudinal centre axis of the control bolt, and the extent of which perpendicularly to the control cam pivot axis, for example its outer diameter, is greater than a width of the slotted groove assigned to the control bolt transversely to its longitudinal extent, and/or which is formed as a connecting web between the two control bolts. 
     A sliding plate may be provided between a carrier plate of the clamping device on which the clamping arms and/or the control cam are mounted, and the clamping arms, for providing a slide bearing between the carrier plate and clamping arms. 
     Alternatively or additionally, on a side of the clamping arms by which they may be attached to the container transport device of a container treatment device, in some embodiments a top side of the clamping arms, a sliding plate may be provided in order to provide a slide bearing of the clamping arms relative to the container transport device on which the clamping device may be arranged. 
     The clamping arms and/or the carrier plate may be made of a metal, for example a steel alloy. In one or more embodiments, the sliding plate is made from a material different from the carrier plate and/or the clamping arms, or coated with such a material, for example a plastic, a copper alloy or a brass alloy. 
    
    
     
       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 clamping device for holding a beverage container at a neck portion; 
         FIG.  2    shows schematically a top view of a clamping device according to a further embodiment, in a closed position; 
         FIG.  3    shows schematically a top view of a clamping device from  FIG.  2    in an open position; 
         FIG.  4    shows schematically a top view of a clamping device according to a further embodiment, in a closed position; 
         FIG.  5    shows schematically a top view of a clamping device from  FIG.  4    in an open position; 
         FIG.  6    shows schematically a perspective side view of a clamping device according to a further embodiment; 
         FIG.  7    shows schematically a view from below of the clamping device from  FIG.  1   ; 
         FIG.  8    shows schematically a perspective side view from below of a part region of the clamping device from  FIG.  1   ; 
         FIG.  9    shows schematically a view from below of a clamping device according to a further embodiment; 
         FIG.  10    shows schematically a view from below of a clamping device according to a further embodiment; 
         FIG.  11    shows schematically a perspective side view of a clamping device according to a further embodiment; 
         FIG.  12    shows schematically a perspective side view of a clamping device according to a further embodiment; 
         FIG.  13    shows schematically a top view of a clamping device according to a further embodiment; 
         FIG.  14    shows schematically a top view of an upper part of a control cam, similar to the embodiment of  FIG.  13   ; 
         FIG.  15    shows schematically a side view of the part from  FIG.  14   ; and 
         FIG.  16    shows schematically a clamping device according to a further embodiment. 
     
    
    
     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 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  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 via a coupling mechanism  30 . Accordingly, 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  comprises two pairs of a respective slotted groove  31 ,  31 ′ and a 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 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. 
     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 , 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  21  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 holding device for holding 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 handling device for switching the control cam  20 , and the lever arm present between the control bolts  32 ,  32 ′ and control cam pivot axis  21 , lies substantially between 5:1 and 3:1, and is in one embodiment 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.  2    shows schematically a top view of a clamping device  1  according to a further embodiment. The clamping device  1  shown in  FIG.  2    nonetheless substantially corresponds to that of  FIG.  1   . 
     In particular, a common factor of the embodiments of Fs 1 and 2 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.  1  and  2    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.  1   , in the embodiment of  FIG.  2   , 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.  3    shows schematically a top view of the clamping device  1  from  FIG.  2    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.  2   . 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.  4  and  5    each show schematically a top view of a clamping device  1  according to a further embodiment, in a closed position ( FIG.  4   ) and an open position ( FIG.  5   ). The clamping device  1  substantially corresponds to the clamping device  1  from  FIG.  1   . 
     In contrast to the clamping devices  1  from  FIG.  1    and  FIGS.  2  and  3   , the clamping device  1  in  FIGS.  4  and  5    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.  6    shows schematically a perspective side view of a clamping device  1  according to a further embodiment, which substantially corresponds to that of  FIG.  1   . 
     In the clamping device  1  according to  FIG.  6   , in contrast to the embodiment of  FIG.  1   , the control bolt  32 ′ has a cam portion  322 . 
     At its end face viewed in the direction of the control cam pivot axis  21 , the control bolt  32  has a locking web  323 , in this case formed 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.  6   , not arranged on a container transport device, the control cam  20  is held on the clamping arm  10 . 
     With reference to  FIGS.  7  and  8   , the pretension device  40  which is common to  FIGS.  1  to  6    is now described in more detail. 
       FIG.  7    shows schematically a view from below of the clamping device  1  from  FIG.  1   , and  FIG.  8    shows schematically a perspective side view from below of a part region of the clamping device  1  from  FIG.  1   . 
     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.  1  to  8   , the pretension device  40  comprises a spring element  41  arranged on the control cam  20 , in the present case a curved leaf spring, which extends between the arms  24  substantially in the circumferential direction relative to the control cam pivot axis. As shown in  FIG.  7   , 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.  8   , 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. 
     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.  8   , 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 of the running roller  42  together with the spring force 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 some 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.  9    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.  8    with the exception of the embodiment of the pretension device  40 . Instead of the continuous leaf spring which is attached to or transforms into the arms  24  at both ends, in this embodiment, the control cam  20  comprises a web  46  extending substantially centrally between the arms  24  radially outwardly to the pitch circle  45 , and a spring element  41  which extends at the radially outer end of said web on each side, substantially in the circumferential direction or tangentially thereto with respect to the control cam pivot axis  21 , in the form of a bending bar with a 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 . The running roller  42  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.  8   , the running roller  42  may be mounted eccentrically to the bearing centre axis  44  and/or pretensioned against the control cam. 
       FIG.  10    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.  8    with the exception of the embodiment of the pretension device  40 . Instead of the spring element  41  provided as a continuous leaf spring, a bolt  47  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.  8   , 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.  8   , the running roller  42  may be mounted eccentrically to the bearing centre axis  44  and/or pretensioned against the control cam. 
       FIG.  11    shows schematically a perspective side view of a clamping device  1  according to a further embodiment, which substantially corresponds to that of  FIG.  9   . 
     In this embodiment, like the embodiment of  FIG.  1   , 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.  6   . In addition, in comparison with the embodiment in  FIG.  1   , it provides an increased bending stiffness of the control bolt  32  in the radial direction relative to the control cam pivot axis  21 . 
       FIG.  12    shows schematically a perspective side view of a clamping device  1  according to a further embodiment, which substantially corresponds to that of  FIG.  1   . 
     The control bolts  32  in this embodiment, in contrast to the embodiment of  FIG.  1   , each have a cam portion  322  as already described with reference to the control bolt  32 ′ from  FIG.  6   . 
     Furthermore, the pretension device  40  is configured as a magnetic pretension device  40 . To this end, the stop  3  has a magnet  50  which cooperates with a magnetic element  51  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. 
     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.  13    shows schematically a top view of a clamping device  1  according to a further embodiment, which substantially corresponds to that of  FIG.  1   , wherein the pretension device  40  is a magnetic pretension device according to  FIG.  12   . 
     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  13 , 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  provided on an end face pointing in the direction of the clamping arms  10 , in  FIG.  13    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.  14  and  15    show schematically a top view and a side view of an upper part of a control cam  20 , similarly to the embodiment in  FIG.  13   , 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.  15    shows the embodiment of the slotted grooves  31  as blind holes. 
       FIG.  16    shows schematically a clamping device  1  according to a further embodiment. The clamping device  1  substantially corresponds to that of  FIG.  1    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 . 
     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.  6   . 
     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 of the invention.