Abstract:
The invention relates to a closure head for container closure machines ( 1 ) for closing bottles or similar containers with closures, having a head part, having a receptacle formed on a head part and open on the bottom of the closure head and the head part for one closure each, wherein the receptacle forms at least one radial and at least one axial contact surface relative to an axis of the receptacle for the closure received in the receptacle, and wherein the radial contact surface for at least force-fit retaining of the closure in the receptacle is formed of at least one displaceable segment displaceable at least radially to the axis of the receptacle at least in the area of the radial contact surface.

Description:
This application is the National Stage of International Application No. PCT/EP2009/008957, filed on Dec. 15, 2009, which claims the priority of German Patent Application No. 10 2009 005 150.3, filed on Jan. 15, 2009. The contents of both applications are hereby incorporated by reference in their entirety. 
     FIELD OF DISCLOSURE 
     The invention relates to a closure head for use on container closure machines for closing bottles or similar containers with closures, for example with screw caps, according to the preamble of claim  1 . The invention furthermore relates to a container closure machine for closing bottles or similar containers with such closures according to the preamble of claim  15 . 
     BACKGROUND 
     Container closure machines for closing bottles or other containers are known in various embodiments. In particular container closure machines are known for closing bottles or other containers with screw caps. These caps are applied to the containers by screwing onto an external thread provided in the area of the container opening concerned, namely by screwing with a closure tool which is equipped with a closure head forming a receptacle for the respective closure. In detail, the container concerned is closed such that the respective cap is first held in the receptacle of the closure head. Then the cap held in the closure head at least by force-fit i.e. by clamping, is placed on the container opening and then screwed onto the respective container by the closure head driven rotationally about a closure head axis or receptacle axis. A force-fit connection does not exclude the provision of grooving and/or fluting which allows at least a partial form fit by interlocking of opposing surface contours. 
     SUMMARY 
     During the screwing, the container lies pressed against the closure head or against the cap held in the closure head axially i.e. in the direction of the axis of the receptacle with a certain force, for example with a force of 20 kp or around 200N. 
     For reliable and adequately tight closure of the containers it is necessary for the respective container closure to be screwed sufficiently firmly i.e. with a sufficiently high torque onto the container to be closed, irrespective of any tolerances which container closures normally have, in particular in relation to the effective external diameter, which can greatly detract from the force fit connection or clamp fixing of the container closure in the closure head. 
     The object of the invention is to produce a closure head which even with greater tolerances of the container closures guarantees reliable closing of bottles or similar containers. To achieve this object a closure head is formed according to claim  1 . A container closure machine is the object of claim  15 . 
     Refinements, benefits and possible applications of the invention arise from the description below of embodiment examples and from the figures. All features described and/or shown in the figures, alone or in any combination, in principle belong to the object of the invention irrespective of their summary in the claims or any back reference. The content of the claims is also declared a constituent part of the description. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       The invention is explained below with reference to the figures and one embodiment example. These show: 
         FIG. 1  a simplified view of a container closure machine of the common type for closing bottles or similar containers with container closures in the form of cap-like screw closures; 
         FIG. 2  in perspective individual view, the closure head of a closure tool or screw closure of the container closure machine in  FIG. 1 ; 
         FIG. 3  the closure head of  FIG. 2  in perspective individual view and in cross section, together the screw cap also shown in cross section; 
         FIG. 4  the closure head in vertical section together with a partial depiction of a screw cap. 
     
    
    
     DETAILED DESCRIPTION 
     The container closure machine designated generally as  1  in  FIG. 1  of a common type serves for closing bottles  2  with cap-like screw closures  3  which are made for example from one piece of plastic with a base  3 . 1 , a cap edge  3 . 2  and fluting  3 . 2 . 1  on the cap edge  3 . 2 . This external fluting  3 . 2 . 1  usually corresponds to the inner contouring  21  of an individual head piece  16 . 
     The container closure machine  1  in the manner known to the skilled person comprises a rotor  4  that can be driven circulating about a vertical machine axis MA, on the periphery of which rotor are formed several closure stations  5  etc. each with a closure tool  6  in the form of a closure screw and each with a container carrier  7  for suspended mounting of the respective bottle  2 . The closure tools  6  of the closure stations  5  essentially each comprise an electric motor drive  8 , a spindle  9  which is oriented with its axis parallel to the vertical machine axis and which with its upper end is connected driven with the drive  8  or with the motor shaft of this drive  8 , and a closure head  10  provided at the lower end and sprung axially. When the rotor  4  rotates, this head picks up the respective screw closure  3  at a cap delivery position not shown, then by raising the respective bottle  2  places it with the bottle neck against the closure head  10  and then the closure head  10 , driven rotating about its axis VA via the drive  8  and the spindle, screws the closure onto the respective bottle  2  or onto an external thread provided in the area of the bottle neck, as is also known to the specialist. Naturally the specialist is also aware of central mechanical drives for the closure device and drives mechanically derived therefrom for the spindles  9  or devices with which the closure head  10  is lowered onto a standing or suspended bottle. 
     As shown in particular from  FIGS. 2 to 4 , each closure head  10  comprises amongst others a bearing element or a closure head base  11  which is provided at the lower end of the spindle  9  or spindle section, sprung mobile in the axial direction of the spindle  9 , or connected driven with the spindle  9 . The closure head  10 , with its closure head axis VA coaxial to the spindle axis, is attached to the spindle  9 . 
     The closure head base  11  is made as a moulding from a suitable material, for example a metallic material, as one piece with an upper plate-like base section  12  which in the embodiment shown in top view has a substantially square form, and has four corner posts  13  each provided on a corner area of the section  12  and protruding beyond a common underside of the base section  12 . The corner posts  13  are each produced as an angle piece with two legs  13 . 1  which are arranged at least with their external surface sides facing away from each other in planes parallel to the axis VA and perpendicular to the top and bottom of the base section  12  and also perpendicular to any peripheral side of this base section  12 . 
     The two legs  13 . 1  of each corner post  13  enclose together, on their surface sides facing towards each other, an angle of 90° which open towards the periphery of the closure head  10  or closure head base  11 . In a variant not shown, the posts are not designed as angle pieces with two legs but as fingers or columns so that each finger or each column serves as a receptacle and/or mount for one or two joints. The closure head base  11  is furthermore formed with an opening  14  in the centre of the base section  12  which serves to fix the closure head  10  to the spindle  9  and on the inside is fitted with a suitable connecting means, for example an internal thread. To reinforce the closure head base  11  in the area of the opening  14 , the base section  12  on its top is formed as one piece with the ring-like protrusion  15  surrounding the opening  14 . 
     Each closure head  10  furthermore comprises a sleeve-like head piece  16  which serves to hold the screw cap  3  and to screw this cap  3  onto the respective bottle  2  to be sealed. The sleeve-like head piece  16  in the embodiment shown is formed from a total of four segments  17  which supplement each other to form the sleeve-like head piece  16  and to these are connected adjacent surfaces  18  which lie in a plane oriented radially or substantially towards the axis KA of the sleeve-like head piece  16 . 
     The head piece  16  on the inside forms an opening  19  which is open at the upper end  16 . 1  of the head piece  16  adjacent to the underside of the base section  12  but spaced slightly therefrom and at the lower end  16 . 2  of the head piece  16  facing away from the base section  12 . At least when there is no screw cap  3  in the closure head  10  or head piece  16 , the segments  17  in the area of the lower end  16 . 2  of the head piece  16  lie against each other with surfaces  18  so that the axis KA of the head piece  16  formed by the axis of opening  19  coincides with axis VA, and the inner surface of the opening  19  both in the upper opening section  19 . 1  and in a lower section  19 . 2  is formed circular cylindrical or substantially circular cylindrical. 
     The internal diameter of the opening section  19 . 1  in the embodiment shown is slightly larger than the internal diameter of the opening  14 . The internal diameter of the opening section  19 . 2  is slightly larger than the internal diameter of the opening section  19 . 1 . The opening section  19 . 1  forms the receptacle  20  to receive and hold a screw cap  3  by clamping. With head piece  16  empty i.e. with no screw cap  3  in the receptacle  20 , the internal diameter of the opening section  19 . 2  is therefore slightly smaller than the outer diameter of the cap-like screw closure  3 . 
     At the inner surface forming a radial contact surface  21  for the screw caps  3 , the opening section  19 . 2  is fitted with fluting which corresponds to the fluting  3 . 2 . 1  on the periphery or cap edge  3 . 2  of the screw closure  3 , so that each screw cap  3  held in the receptacle  20  with its fluting  3 . 1  engages in the fluting of the contact surface  21 . 
     To facilitate the introduction of the screw cap  3  into the head piece  16  or receptacle  20 , the head piece  16  and the segments  17  forming this head piece are designed with a rounded face at the lower end  16 . 2 . Furthermore at the lower end  16 . 2 , the opening section  19 . 2  transforms into a slightly larger diameter opening section  19 . 3 , which then forms the lower open end of the opening  19  or receptacle  20 . 
     The step-like transition between the opening sections  19 . 1  and  19 . 2  in the opening  19  forms an annular axial contact surface  22  against which the screw cap  3  held in the receptacle  20  rests with its base  3 . 1  during closure, whereby a clear axial positioning of each screw cap  3  in the receptacle  20  is achieved. 
     The segments  17  are each fitted with two retaining arms  23  formed as tabs or lugs which protrude over the outer surface of these segments or the head piece  16  in the embodiment shown, such that the two retaining arms  23  are offset to each other in an axial direction tangential to the circle concentrically surrounding the axis KA, and each retaining arm  23  is in an area of the surface  18 , and substantially closer to the top  16 . 1  of the head piece  16  than the bottom  16 . 2  of the head piece. Using bearing bolts  24  which extend through bearing bores  25  into the retaining arms  23  and are each held at both ends on one of the corner posts  13 , the segments  17  are connected pivoting with the closure head base  11 . 
     In detail the bearing bolts  24  extend between two corner posts  13  and are oriented with their axis parallel to one side of the substantially square base section  12  of the closure head base  11  and hence tangential to a circle line concentrically surrounding axes VA and KA so that segments  17 , at least at the lower end  16 . 2  of the head piece  16 , can be swivelled about the axis of the respective hinge bolt  24  radially outward and inward in relation to axis KA. With their sides facing away from each other, the retaining arms  23  each rest against a leg  13 . 1  of the corner post  13  concerned so that the segments  17  are held on the hinge bolts  24  immobile in the axial direction of the hinge bolts  24 . 
     In the area of the lower end  16 . 2  on the outer surface of the head piece  16  is provided an annular spring element  26  concentrically surrounding axis KA, which element for axial fixing engages in a ring groove on the outer surface of the head piece  16  and in the embodiment shown of an O-ring is formed from a rubber elastic material. With this spring element  26  the segments  17  are pretensioned sprung radially inwards in relation to axis KA to fix the screw cap  3  in the receptacle  20 . 
     The segments  17  including their retaining arms  23  are each made identically of a suitable material, for example a metal or suitable plastic, so that the closure head  10  is formed mirror- and rotationally symmetrical in all planes enclosing the axis VA and KA and oriented perpendicular to the peripheral sides of the sealing head base  11 . Naturally asymmetrical embodiments are also conceivable or embodiments in which at least one segment  17  is not mounted suspended but is rigidly connected with the closure head base  11 , in particular the base section  12 . 
     As  FIG. 4  in particular shows, the swivel axis of each segment  17  formed by the respective hinge bolt  24  has a radial distance X from the axis VA and/or KA which is greater than the maximum radial distance x between the contact surface  22  formed axially on this segment  17  and the axis VA and/or KA. This means that due to pressure forces F acting on the contact surface  22  via a screw cap  3  held in receptacle  20 , moments M about the axis of the pivot bolts  24  result which act in the sense of closing the head piece  16  i.e. in the sense of swivelling the segments  17  radially inwards so that the screw cap  3  concerned is held even more securely in the receptacle  20  by clamping. 
     When the screw cap  3  concerned is picked up, this is introduced into the receptacle  20  with a slight opening of the head piece  20  i.e. a slight swivel of segment  17  at the lower end  16 . 2  against the action of spring element  26 , and held clamped in this receptacle by the action of the spring element  26 . The base  3 . 1  lying against the contact surface  22  puts this screw cap  3  in the receptacle  20  in a specified position in which this screw cap protrudes with its lower open edge area beyond the underside  16 . 1 . After the screw cap  3  has been placed on the mouth area of a bottle  2 , the bottle  2  is pressed with force F of for example 20 kp or around 200N against the screw cap  3  so that due to this force F, via each segment  17  an additional radial clamping force F′ is exerted on the cap  3  held in the receptacle  20 . The size of the clamping force F′ arises from the force F and the translation ratio of the lever arms a and A. 
     Thus the lever arm a is the mean active distance of the axial contact surface  22  from the axis of the associated pivot bolt  24 , and lever arm A is the mean active distance of the radial contact surface  21  from the axis of this mounting bolt  24 . 
     It is therefore possible, depending on the individual closure and the necessary closure force, to adjust or vary the clamping force in the desired manner by changing the lever arms or lever arm ratio a to A and/or y to Y. 
     After screwing the screw cap  3  onto the respective bottle  2 , by the elimination of force F and the additional contact force F′ due to lowering of the bottle  2  from the closure head  10  and/or by raising the closure head  10  from the bottle  2 , the closure head  10  can easily be separated from the screw cap  3  screwed onto the bottle  2 . 
     As  FIG. 4  also shows, the distance Y of each hinge bolt  24  from a reference plane BE oriented perpendicular to axis KA and enclosing the open side of the receptacle  2  is greater than the distance y of the axial contact surface  22  from this reference plane BE. 
     In particular due to the arrangement of the swivel axes of segments  17  formed by the bearing bolts  24  in relation to the axial contact surface  22 , the closure head  10  offers the advantage of achieving a reliable clamping of the respective screw cap  3  due to the additional radial clamping force F′ even at greater tolerances also of the diameter of the screw cap  3 . Such tolerances are for example due to an uncontrollable or only partly controllable shrinkage of plastic screw caps  3  and/or an ink application not controllable or only partly controllable in thickness onto the screw cap  3 . 
     In an embodiment not shown it is provided that the hinge bolts  24  lie in a plane which intersects the segments  17  in the middle or below the middle, and this plane stands perpendicular to axis KA. In such a case it can be advantageous that instead of the spring element  26  applied from the outside at the lower end onto the segment  17 , one or more spreading spring elements are arranged on the upper end. As will be evident to the skilled person, in such embodiment variants some of the lever arm ratios described above deviate depending on the desired force effect or must be adapted accordingly. 
     The invention has been described above with reference to one embodiment example. It is evident that numerous changes and derivations are possible without leaving the inventive concept on which the invention is based. 
     It has been assumed above that the head piece  16  has a total of four displaceable segments  17  provided swivelling on the closure head base  11 . The number of displaceable segments  17  may also differ from this. Thus for example two or three or more than four segments  17  can be provided which are then each swivellable about axes arranged in a common plane tangential to the circle line surrounding concentrically the closure head axis VA. 
     REFERENCE NUMERAL LIST 
     
         
           1  Container closure machine 
           2  Bottle 
           3  Cap-like screw closure 
           3 . 1  Base of screw closure 
           3 . 2  Cap edge of screw closure 
           3 . 2 . 1  Fluting 
           4  Rotor 
           5  Closure station 
           6  Closure tool 
           7  Container carrier 
           8  Drive 
           9  Spindle 
           10  Closure head 
           11  Closure head base 
           12  Base section 
           13  Corner posts 
           13 . 1  Leg 
           14  Fixing opening 
           15  Annular protrusion 
           16  Head piece 
           16 . 1  Top of head piece  16   
           16 . 2  Bottom of head piece 
           17  Segment of head piece  16   
           18  Surface 
           19  Head piece opening 
           19 . 1 - 19 . 3  Opening section 
           20  Receptacle 
           21  Radial contact surface with fluting 
           22  Axial contact surface 
           23  Retaining arm 
           24  Hinge bolts 
           25  Bearing bore 
           26  Spring element 
         a, A Lever arm 
         x, X Radial distance 
         y, Y Axial distance 
         F Axial contact force 
         F′ Radial contact force 
         M Moment 
         BE Reference plane 
         KA Axis of head piece  16   
         VA Axis of closure head  10