Patent Publication Number: US-9845230-B2

Title: Closing device including intertwined sliding cage and gripping part

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of international patent application PCT/EP2013/071188, filed on Oct. 10, 2013, which claims the priority of German patent application DE 10 2012 020 026.9, filed Oct. 12, 2012, the whole contents of these applications are hereby included by reference. 
    
    
     BACKGROUND 
     The invention relates to a closing device, in particular for bottles, jars, pots or similar packaging containers for pharmaceutical or cosmetic products, having a rotationally drivable screw head for screwing a closure, for example a screw cap, onto the container which screw head has on a carrier a gripping part for grasping a closure and is actuable between a release position and a clamping position. 
     In the closure of containers in the cosmetics and pharmaceutical sector, rotating screw heads are used. In these, the gripping part has jaws which are movable by joints in a pivot motion between the release position and the clamping position and consist of metal. Each screw head further has a multitude of further component parts for its functionality. Owing to the large number of components, such screw heads are complicated and heavy. They require a relatively high complexity of assembly. Another drawback is a relatively large moment of inertia, which is an obstacle to a desired increase in the number of cycles. Desired shorter screwing times lead to difficulties in the controllability of the tightening torque of closures which are to be screwed on. 
     It is an object to provide a closing device of the type stated in the introduction, which is simplified by fewer components, enables a reduced weight and a reduction in costs and has a lower moment of inertia, wherein, due to the reduced moment of inertia, the tightening torque shall be better controllable and an increase in the number of cycles and a resulting shorter screwing time is achieved. 
     SUMMARY 
     There is provided, according to one aspect, a closing device, having a rotationally drivable screw head for screwing a closure onto the container, which screw head has on a carrier a gripping part for grasping a closure and is actuable between a release position and a clamping position, wherein the gripping part is embraced by a sliding cage for actuation by relative movement, and in that both the gripping part and the sliding cage are configured as a monolithic component and the two are intertwined in such a way that parts of the sliding cage reach through openings in the gripping part into the interior thereof and as far as a lifting apparatus in the carrier. 
     According to another aspect, the closing device, in terms of the screw head, is reduced practically to just two components, namely the one-piece gripping part on the one hand and the likewise one-piece sliding cage on the other hand, which latter embraces the gripping part at the end from outside, for actuation thereof, and due to the entwinement with an integral functional part, reaches through openings in the gripping part into the interior thereof, where the lifting apparatus in the carrier acts on the sliding cage for relative displacement of the same relative to the gripping part. An extremely simple design is thus obtained. The number of components, the production costs and the weight are substantially reduced. The moment of inertia, too, is lowered. In addition, a low complexity of assembly is obtained. Overall, the present closing device leads to a considerable reduction in costs and simplification of the screw head. Due to the lowered weight and the reduced moment of inertia, the tightening torque involved in the screwing on of a closure is better controllable and an increase in the number of cycles is realizable with consequential shorter screwing time. 
     Advantageous refinements of the present closing device emerge from the dependent claims. Further details and advantages are defined in the following description and are also apparent from the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention is explained in greater detail below with reference to an illustrative embodiment shown in the drawings, wherein: 
         FIG. 1  shows a schematic side view with partial perspective view of a screw head of a closing device in the release position, 
         FIG. 2  shows an end-face view of the screw head in  FIG. 1 , 
         FIG. 3  shows a schematic, partially sectioned side view of the screw head in  FIG. 1  in its release position, and 
         FIG. 4  shows a schematic, partially sectioned side view in accordance with that in  FIG. 3 , in which the screw head is in the clamping position. 
     
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
     In the drawings, a screw head  10  of a closing device, in particular for bottles, jars, pots or similar packaging containers for pharmaceutical or cosmetic products, is shown in schematic representation. The screw head  10  is rotationally drivable by means of a drive device (not further shown) in order to screw a closure, for example a screw cap, onto the container. Moreover, the screw head  10  is movable up and down in the direction of its center longitudinal axis  11 . 
     The screw head  10  has on a carrier  12  a gripping part  13  for grasping a closure (not shown) for the container and is actuable between a release position according to  FIG. 3  and a clamping position according to  FIG. 4 . 
     The gripping part  13  is embraced by a sliding cage  14 , which is configured to actuate the gripping part  13  by relative movement. Both the gripping part  13  and the sliding cage  14  are configured as a monolithic component. The two are intertwined in such a way that parts of the sliding cage  14 , namely arms  15 , reach through openings  16  in the gripping part  13  into the interior  17  thereof, and there as far as a lifting apparatus  18  in the carrier  12 . 
     As can be seen, in particular, from  FIG. 1 , the openings  16  in the gripping part  13  consist of approximately slit-like vertical wall apertures  19  in a wall part  20  of the gripping part  13 . In the drawings, the wall part  20  passes upward into a therewith integral holder  21 , on which is configured a flange with which the holder  21  is detachably fastened to the carrier  12 , for example by means of screws. In the drawings, extending downward from the wall part  20  are therewith integral gripping arms  22 ,  23  and  24 , which at the lower end have respective gripping jaws  25 ,  26  and  27 . The gripping jaws  25  to  27  have inlays, for example of soft elastic material, for example rubber. 
     The gripping arms  22  to  24  are relative to the wall part  20  elastic and movable, due to joints  28 ,  29  in the form of material thin points of the gripping arm material. The joints  28 ,  29  in the form of the material thin points are permanently elastic. 
     In the shown illustrative embodiment, the gripping part  13  has three gripping arms  22  to  24  arranged at approximately equal peripheral angular distances apart. Self-evidently, in another illustrative embodiment (not shown), two gripping arms, or four or more gripping arms, for example, can instead be provided. Since the gripping part  13  is connected via the holder  21  at the end of the wall part  20  fixedly to the carrier  12 , the movement of the carrier  12  is imparted to the gripping part  13 , which exercises the same movement. 
     The sliding cage  14  has, as the lower element cooperating with the gripping arms  22  to  24 , an annular part  30 , which is integrally connected to the arms  15  via respective connecting struts  31 . The annular part  30  forms a portion which tapers approximately frustoconically in an axial direction, to be precise in the upward direction in the drawings. With this portion in the form of the annular part  30 , the sliding cage  14  can bear against facing outer surfaces  32 ,  33  of the gripping arms  22 ,  23  and, in the clamping position, exercise a radially inwardly directed movement and clamping force of the gripping arms  22 ,  23 . 
     The sliding cage  14  preferably has on the tapered portion in the form of the annular part  30 , on the inside, metal covers  34  to  36 , which form the contact surfaces for the outer surfaces  32 ,  33  and contribute to the smoothness of movement and low wear between the friction surfaces. 
     It is particularly advantageous if the gripping part  13 , as a one-piece component consisting of holder  21 , wall part  20 , joints  28 ,  29  and gripping arms  22  to  24 , is formed of plastic, in particular, for example, of polyamide. 
     In the same way, the sliding cage  14 , as the described one-piece structural unit, can also consist of plastic, for example polyamide. 
     The gripping part  13  contains in particular in the lower region of the gripping arms  22 ,  23 , inside these, cavities  37 ,  38 , which are here provided close to the end region and serve to save weight. In addition, above these in the region of the outer surfaces  32 ,  33 , cavities  39 ,  40  can be contained in the gripping arms  22 ,  23 , which cavities are approximately slot-hole-like. As a result, a particular elasticity is conferred in this region to each gripping arm  22 ,  23 , whereby, in the clamping position of the screw head  10 , the radially inwardly acting closing force of the gripping arms  22  to  24  is evenly transmitted by these to the closure to be screwed, for example a screw cap. 
     The gripping part  13  contains a central tube  41 , which on the end-face end bears an elastic axial ring  42 . By the tube  41 , the mounting depth of the screw head  10  onto a closure, for example a screw cap, is predefined. For this purpose, the axial ring  42  forms an elastic stop and can, where necessary, also ensure a seal. Radiating from the tube  41  are radial, therewith integral arms  43 ,  44 ,  45 , via which an expansion element  46 , consisting, for example, of an enveloping O-ring, is clamped. This expansion element  46  bears from the inside against projections  47 ,  48  and  49  of the gripping arms  22  to  24 . In the release position according to  FIG. 3 , the expansion element  46  is untensioned. In the clamping position according to  FIG. 4 , the projections  47  to  49  of the gripping part  13  act on the expansion element  46  radially from the outside inward in such a way that this is clamped in a spring-like manner. Upon release of the gripping part  13 , the expansion element  46  can act in the release position radially outward on the gripping arms  22  to  24 . It forms a return element, which supports the elastic return of the gripping arms  22  to  24 . 
     Between the gripping part  13  and the sliding cage  14  is arranged in the interior  17  an elastic return element  50  which acts on both, for example in the form of a cylindrical helical spring for the sliding cage  14 . 
     On the part  51  which extends inside the wall part  20  and inside the holder  21  of the gripping part  13  and can there be configured, for example, approximately as a cylinder sleeve, which contains the return element  50 , the sliding cage  14  bears a thereto fastened plunger  52 , which is guided in the interior  17  of the carrier  12 . The interior  17  of the carrier  12  is configured as a cylindrical pressure chamber  53  for the plunger  52 . The pressure chamber  53  forms together with the plunger  52  the lifting apparatus  18 , by means of which, when the pressure chamber  53  and the there-situated side of the plunger  52  are pressurized, the plunger  52  can be moved together with the sliding cage  14  relative to the gripping part  13  into the clamping position counter to the action of the return element  50 , under actuation of the gripping part. 
     If, starting from the release position shown in  FIG. 3 , a pressure medium, for example compressed air, is led under pressure into the pressure chamber  53 , then that plunger side of the plunger  52  which is facing toward the pressure chamber  53  is pressurized, whereby the plunger  52 , together with the part  51  and the other components of the one-piece sliding cage  14 , is displaced downward in  FIG. 3  in the arrow direction  54 . The sliding cage  14 , in particular its conical annular part  30 , here slides along the gripping arms  22  to  24 , whereupon, due to the conical design of the annular part  30 , the gripping arms  22  to  24  are moved radially inward into the clamping position shown in  FIG. 4 , in which position a closure, for example a screw cap, is clasped by means of the gripping jaws  25  to  27 . For the creation of the release position according to  FIG. 3 , air is removed, for example, from the pressure chamber  53 , so that the return element  50 , which at the end face is supported against the fixed gripping part  13 , can displace the sliding cage  14 , in opposite direction to the arrow  54 , back into the release position according to  FIG. 3 . The gripping arms  22  to  24  are hereupon moved, with the aid of the expansion element  46 , radially outward into the release position according to  FIG. 3 . 
     The one-piece design of the gripping part  13  on the one hand, and of the sliding cage  14  on the other hand, in particular from plastic, can be cost-effectively produced in a particularly advantageous manner by means of lasers in a sintering process, which also favors production in the described intertwined design. 
     The screw head  10  of the described type has various advantages. The number of individual components is considerably reduced. In addition, the weight of the screw head, also due to lighter material, is substantially reduced. The described component parts of the screw head are able to be produced in a simple and cost-effective manner. Overall, the screw head  10  is considerably cheaper in comparison with known traditional screw heads. The obtained compact construction, wherein, due to the permanently elastic joints formed by thin points of the same material, no distinct joints are necessary for the gripping arms  22  to  24 , is also advantageous. A further advantage lies in an obtained reduction of the moment of inertia of the screw head  10 , the result of which is that, upon use, faster cycle times are possible in respect of the screwing. 
     Advantageously, the plunger  52  can be connected to the part  51  of the sliding cage  14  by bayonet closure, so that, in this respect to, a simplified design is obtained. The one-piece design of the gripping part  13 , and of the sliding cage  14 , from plastic, for example polyamide, is possible through production of these elements by laser sintering in a rapid prototyping process, and thus in a cost-effective and precise manner. As a result of cavities  37  to  40  in the gripping arms  22  to  24  of the gripping part  30 , an additional weight reduction is possible, in addition to which these cavities, in particular the cavities  39 ,  40 , are to this extent usable for transmitting the closing force evenly through the gripping arms  22  to  24  to the closure to be screwed.