Abstract:
A filling valve includes a valve seat, an axially-movable valve tappet extending through the valve seat and having an axial portion that defines a product-delivery space through which filling product flows, and axially-displaced first and second seal-seats disposed so that liquid product flows from the first seal-set, through the product-delivery space, to the second seal-seat and out through an outlet. The first seal-seat and the second seal-seat are arranged on the valve tappet in such a way that, in response to a closing movement of the valve tappet, the first seal-seat closes before the second seal-seat, and wherein the first seal-seat, after having been closed as a result of the closing movement, permits further axial movement of the valve tappet to permit closing of the second seal-seat.

Description:
RELATED APPLICATIONS 
       [0001]    This is the national stage under 35 USC 371 of international application PCT/EP2015/071371, filed Sep. 17, 2015, which claims the benefit of the Sep. 18, 2014 priority date of German application DE 10-2014-113-488.5, the contents of which are herein incorporated by reference. 
     
    
     FIELD OF INVENTION 
       [0002]    The invention relates to a filling valve used to fill containers with liquid filling-product that may contain particles and long fruit fibers. 
       BACKGROUND 
       [0003]    Filling machines rely on filling valves to fill bottles. In many cases, filling valves that work with some filling products do not work with other filling products. These difficulties arise from the nature of the filling products. For examples, some filling products have suspended solids, such as fruit fibers. Other filling products have low viscosities. 
       SUMMARY 
       [0004]    An object of the invention is to provide a filling valve that can both fill with products with solid particles, such as small pieces of fruit, as well as fill with products of different viscosities. 
         [0005]    In one aspect of the invention, the filling valve has at least one valve tappet that is arranged to be movable axially through an axially-extending channel along a valve seat that defines an inner-wall of the valve. Liquid filling-product thus flows along an axial portion of the valve tappet through the axially-extending channel. The liquid filling product flows from a first seal-seat to a second seal-seat that is formed at an outlet end of the filling valve. 
         [0006]    In some embodiments, the axially-extending channel is an annular gap. However, it can also be any lateral channel parallel to the filling valve axis. 
         [0007]    The filling valve has a first seal-seat and a second seal-seat that are axially displaced from each other, with the second-seal seat being downstream of the first seal-seat. In some embodiments, the first seal-seat comprises an elastic seal-element. The first seal-seat and the second seal-seat are arranged in such a way that, when the valve tappet executes a closing movement, the first seal-seat closes before the second seal-seat. Moreover, the first seal-seat, after having been closed, allows further axial movement of the valve tappet in the closure direction until the second seal-seat also closes. As a result, closing the filling valve is a two-stage or two-phase endeavor with a time delay between a first phase and a second phase thereof. 
         [0008]    In the foregoing configuration, the second seal-seat no longer leaves a gap open, but is likewise closed after the first seal-seat, possibly in its own movement step. This means that after closing the first seal-seat, the filling process is ended. But any product present upstream of the second seal-seat and downstream of the first seal-set remains there because the gap that remains at the second seal-seat is so small that it functions as a gas barrier and counteracts any ingress of gas. With the closing of the second seal-seat, which only takes place after a time delay, no more product sprays into the bottle located below, or onto the surrounding area. This is the case even if the liquid filling-product has very low viscosity. 
         [0009]    The time delay before the second seal-seat closes means that any filling product present in the axially-extending channel cannot escape. Nor can any gas rise therein. The filling valve&#39;s ability to fill is therefore independent of the filling product&#39;s viscosity, at least within the viscosity ranges that are usual for drinks. 
         [0010]    According to the invention, therefore, after having reached the filling quantity of a container that is to be filled, the valve tappet moves far enough to close first seal-seat, thus leaving a gap in the second seat. This effectively forms a gas barrier. As a result, the filling valve is able to end the filling process without the filling product being sprayed. 
         [0011]    A short time later, i.e. preferably 30-300 milliseconds later, further movement of the valve tappet closes the second seal-seat. The time period between the closing of the first seal-seat and the second seal-seat is so short that no gas can rise into the axially-extending channel between the two seal seats. This avoids premature emptying of the product present therein, even when the filling product has very low viscosity. The further movement of the valve tappet after having closed the first seal-seat is preferably less than 2.5 millimeters. An appropriately designed first seal-seat will accommodate this further movement as described below. 
         [0012]    In some embodiments, the axially-extending channel between the first seal-seat and the second seal-seat forms an annular gap. This annular gap is large enough to permit unimpeded flow of liquid filling products that have solid constituents, such as small pieces of fruit, as well as for liquid filling-products with high viscosity. Due to the control of the second seal-seat, the viscosity dependence between the annular gap and the gap at the second seal-seat no longer applies because the second seal-seat closes completely shortly after the first seal-seat closes. 
         [0013]    The resulting filling-valve allows the filling jet to be adjusted optimally for very low turbulence and minimal foam formation, as well as high discharge capacity and the processing of large particles. The impediment of having to take account of a functioning gas barrier no longer applies. This means that products with very differing viscosities can be handled. 
         [0014]    There are various different possibilities for configuring the first seal-seat to allow it to accommodate further axial movement of the valve tappet in the closing direction. 
         [0015]    In some embodiments, the first seal-seat comprises at least one highly-elastic sealing-element that, after the closing of the first seal-seat, can be deformed to such an extent that it takes part in the axial movement of the valve tappet without losing the sealing effect in reciprocal action with the other sealing element of the first seal-seat. Such a configuration of the first seal-seat requires no moving parts at the first seal-seat. The further axial movement of the valve tappet can readily be accommodated based solely on the flexibility or deformability of the first seal-seat and on the highly elastic properties of one or both sealing elements thereof. 
         [0016]    In other embodiments, at least one of the sealing elements of the first seal-seat is arranged such that it can be axially displaced, either at the valve tappet or at the valve seat. This axial displacement capability makes it possible for the corresponding axially-displaceable sealing-element, after the closing of the first seal-seat, to move along with the axial movement of the valve tappet without breaking its seal. It is therefore possible, for example, for the axially-displaceable sealing-element of the first seal-seat to be held on an axially-movable carrier that is mounted such as to be axially-movable either at the valve tappet or at the valve seat. The carrier can be formed, for example, by a metal sleeve, which can be provided such as to slide easily on the valve tappet or the valve seat. 
         [0017]    Preferably, a carrier, or the axially-movable sealing-element, is held in a resting position by a spring such that the further movement of the valve tappet after the closing of the first seal-seat is realized by having the carrier be pressed out of its resting position against the force of the spring. At the opening of the filling valve, i.e., during actuation of the valve tappet away from the outlet end, the second seal-seat opens first. Following this, between these two actions, the carrier returns to its resting position. Such a device is reliable and retains its functional capacity even after frequent actuation of the valve tappet. 
         [0018]    In some embodiments, the carrier is sealed against the valve tappet or valve seat by folding bellows elements such that no product can ingress between the carrier and the valve tappet or valve seat respectively on which the carrier is mounted. Among these embodiments are those in which the bellows elements also form a spring that defines a resting position for the carrier. 
         [0019]    In some embodiments, an elastic ring-seal and a shoulder against which the ring seal lies in contact form sealing elements of the first seal-seat. For the sake of simplicity, the ring seal is preferably formed on the valve tappet, and the shoulder is a change of diameter, preferably a clearly perceptible change, at the valve seat. It is also possible, however, for the ring seal to be arranged at the valve seat, and for the shoulder to be on the valve tappet. 
         [0020]    In some embodiments, the ring seal contains an annular seal-lip that extends transversely to the direction of the tappet&#39;s movement. Such a seal lip, due to its geometry and with the corresponding size of the annular gap in the axial portion between the valve tappet and the valve seat, has an adequate deformability such as to allow, after the contact at the shoulder, for a further axial movement of the valve tappet as far as the closure of the second seal-seat. 
         [0021]    Preferably, the first seal-seat, after closing, allows for a further axial actuation of the valve tappet in the closing direction of at least 1 millimeter. This allows the time delay between the closing of the first seal-seat and the closing of the second seal-seat to be adjusted and set within wide limits. 
         [0022]    Preferably, the further axial actuation path of the valve tappet after the closing of the first seal-seat amounts to 1.0-2.5 millimeters, preferably 1.5-2.5 millimeters. This further axial actuation path can be provided by controlling the filling device in conjunction with an actuation mechanism for the valve tappet. 
         [0023]    In principle it is possible for the time delay between the closing of the first seal-seat and the closing of the second seal-seat to be achieved by simply moving the valve tappet further in a movement sequence. To speed up the filling process, and also to better control it, it is preferable for the actuation of the valve tappet to be realized by two separate movements: one to close the first seal-seat and another to close the second seal-seat. These can have two different movement speeds. This arrangement also permits the restraining the axial movement of the valve tappet for a brief period after having closed the first seal-seat. 
         [0024]    In another aspect, the invention features a method that includes moving the valve tappet to first close the first seal-seat, and then moving it further to close the second seal-seat. Preferably, the time delay offset between the closing of the first seal-seat and the closing of the second seal-seat is 30-300 milliseconds. This is enough to prevent gas from penetrating into the annular gap of the axial channel and to prevent the escape of the product out of the axial channel. 
         [0025]    It is to be clearly established that a filling device with at least one, and preferably a plurality, of the filling valves referred to heretofore, also comprises a movement mechanism for moving the valve tappet, a control arrangement, as well as a product feed with the corresponding product containers and product lines, and the necessary valves and control elements. The invention naturally also includes a filling device with at least one, and in some embodiments a plurality, of the filling valves described heretofore. 
         [0026]    The exemplary embodiments of the invention referred to heretofore can be combined with one another in any desired manner. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0027]    These and other features of the invention will be apparent from the following detailed description and the accompanying figures, in which: 
           [0028]      FIG. 1  shows a first embodiment of a filling valve according to the invention at three different times, and 
           [0029]      FIG. 2  is a perpendicular section through a second embodiment of the filling valve at the same times as shown in  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION 
       [0030]      FIG. 1  shows a filling valve  10  having a valve seat  12  and a valve tappet  14  that is guided such as to be axially movable. At its upper end, the valve tappet  14  has a valve head  16  by which the valve tappet  14  is not only axially guided in the valve seat  12  but is also gripped by a movement mechanism for axial movement. Actuation elements  20  in the region of the valve head  16  permit a movement mechanism to grip the valve head  16 . 
         [0031]    A spring  18  in the region of the valve head  16  pre-tensions the valve tappet  14  into a resting position. As a rule, this is in the closing direction. 
         [0032]    A product-delivery space  22  extends longitudinally between the valve seat and the valve tappet  14 . This product-delivery space  22  receives liquid from a product-delivery device. 
         [0033]    A lower end of the product-delivery space  22  has a first seal-seat  24 . A ring seal  26  arranged on the valve tappet  14 , a radially-extending seal-lip  27 , and a shoulder  28  arranged on the valve seat  12  cooperate to form the first seal-seat  24  thus forming a sealing element for the product-delivery space  22 . 
         [0034]    At a lower end of the valve tappet  14  is a second seal-seat  30 . The sealing elements of this second seal-seat  30  are formed by an enlarged-diameter drop-shaped thickening  32  of the valve tappet  14  and a seal edge  34  at the lower end of the valve seat  12 . An axial portion  36  extends between the first and second seal-seats  24 ,  30 . This axial portion  36  defines an annular gap through which the product delivered to the product delivery space  22  moves towards the second seal-seat  30 , i.e. towards the lower outlet of the filling valve  10 . 
         [0035]    The highly elastic seal-lip  27  of the ring seal  26  extends outwards so that its outer edge contacts the shoulder  28  of the valve seat  12  in the closing position of the first seal-seat  24 . 
         [0036]    The function of the filling valve  10  at the end of a filling process is described hereinafter on the basis of  FIGS. 1 and 2 , each of which shows operation of the filling valve  10  at three different times, labeled “a,” “b,” and “c.” 
         [0037]    The “a” portion of  FIG. 1  shows the position of the valve tappet  14  during the filling of a product. At this stage of the process, the seal lip  27  is spaced at a distance from the shoulder  28  of the valve seat  24  and the drop-shaped thickening  32  is spaced from the seal edge  34  of the second seal-seat  30 . The product delivered to the product delivery space  22  can therefore flow unimpeded past the first seal-seat  24 , past the second seal-seat  30 , and into a container that would be located beneath the filling valve  10 . 
         [0038]    The “b” portion of  FIG. 1  shows the first phase of filling cessation. In this first phase, the valve tappet  14  moves downward far enough to place the seal lip  27  into contact with the shoulder  28  of the valve seat  12 . This closes the first seal-seat  24 . Meanwhile, a gap remains at the second seal-seat  30 , thus keeping it open. This remaining gap between the drop-shaped thickening  32  and the seal edge  34  is preferably between 0.5 and 1.5 millimeters. 
         [0039]    This remaining gap acts as a gas barrier. As a result, no gas can penetrate into the annular gap  36  located above the second seal-seat  30 . This therefore excludes the possibility of prematurely emptying the axial region or the annular gap respectively. 
         [0040]    The “c” portion of  FIG. 1  shows the second phase of filling cessation. In this second phase, the valve tappet  14  has moved further downwards so that the drop-shaped thickening  32  is in contact at the seal edge  34 . This closes the second seal-seat  30 . Both ends of the annular gap  36  have now been closed off: the upper end by the closed first seal-seat  24 , and the lower end by the second seal-seat  30 . 
         [0041]    As the valve tappet  14  moves further downwards to close the second seal-seat  30 , it severely deforms the elastic seal lip  27 . As a result the seal lip  27  no longer extends radially outwards. Instead, it bends axially to form a plate-shaped structure. Nevertheless, due to its high elasticity, the seal lip  27  remains in contact at the shoulder  28 . This means that the first seal-seat  24  continues to exert its sealing effect even after the valve tappet  14  has been moved downward to close the second seal-seat  30 . 
         [0042]    The filling valve  10  described herein promotes spray-free filling of products derived from liquid that contains solids, as well as for filling products of different viscosities. 
         [0043]    The opening of the second seal-seat  30  for a new filling process runs in the reverse sequence. First, the tappet  14  moves upwards, thus opening the second seal-seat  30 . However, the first seal-set  24  does not open immediately. There is a time delay. Only when the deformation of the seal lip  27  in  FIG. 1  has been relieved does it actually rise up from the shoulder  28  of the first seal-seat  24  to thereby open the first seal-seat  24 . This ensures that the first seal-seat  24  only opens after the second seal-seat  30  has already opened. The time delay between these openings can be adjusted again by the control arrangement of the filling device, and in particular, by controlling the valve tappet&#39;s movement. 
         [0044]      FIG. 2  shows a view similar to that shown in  FIG. 1 , but of a second exemplary embodiment of the invention in which identical or functionally similar parts are provided with identical reference numbers. The first seal-seat  42  of the filling valve  40  from  FIG. 2  is configured differently from the first seal-seat  24  from  FIG. 1 . 
         [0045]    The first seal-seat  42  of the filling valve  40  from  FIG. 2  has, at the valve seat  14  thereof, a shoulder  28  that functions as a sealing surface. This arrangement is identical to that shown in  FIG. 1 . 
         [0046]    In contrast with  FIG. 1 , however, arranged at the valve tappet  14  is an annular sealing element  43 , with an axially displaceable carrier  44 . The carrier  44  is held on the valve tappet  14  by an upper folding bellows element  46  and a lower folding bellows element  47  such as to be axially movable while being tightly connected by corresponding upper and lower portions of the valve tappet  14 , and therefore sealed against the product. Although they can be configured as two pieces, it is useful if the two bellows elements  46 ,  47  are configured as one piece, as is represented in  FIG. 2 . The carrier  44  carries, on its outer circumference, a carrier-seal  48 . Suitable seals include an O-ring seal and a flat seal. In either case, the carrier-seal  48 , at the closing of the first seat seal  42 , contacts the shoulder  28 . 
         [0047]    The sequence at the end of a filling is represented by analogy to  FIG. 1 . In part “a” of  FIG. 2 , the filling valve  40  is opened. In this configuration, both the first seal-seat  42  as and the second seal-seat  30  are opened. 
         [0048]    When closing, the valve tappet  14  travels downwards. This means that the seal  48  contacts the shoulder  28  of the first seal-seat  42 . However, when this occurs, there is still a gap of about one millimeter between the drop-shaped thickening  32  at the lower end of the valve tappet  14  and the seal edge  34  of the second seal-seat  30 . As was the case in  FIG. 1 , this gap functions as a gas barrier that counteracts spraying of the product into a bottle located beneath it or onto the surrounding area. 
         [0049]    In the second phase, the valve tappet  14  moves further downwards. As a result, the drop-shaped extension  32  comes to lie on its seal edge  34 . This closes the second seal-seat  30 . 
         [0050]    At the opening of the filling valve  40  in  FIG. 2 , the second seal-seat  30  opens, and, with a further axial movement of the valve tappet  14  into the opening position, the annular sealing element  43  again moves into its resting position between the upper folding bellows element  46  and the lower folding bellows element  47 , as shown in part “b” of  FIG. 2 . After this, further upward movement of the valve tappet  14  detaches the O-ring seal  48  from the shoulder  28 . This opens the first seal-seat  42  so that a new filling process can begin. 
         [0051]    The invention is not restricted to the exemplary embodiments represented, but can be varied within the scope of protection of the following claims.