Abstract:
A handling unit for hollow glass articles includes
       a plurality of fingers, each configured to engage a corresponding hollow glass article in correspondence of a gripping area and to drag the article along a connection trajectory between a gripping position and a release position,   a displacement mechanism of the plurality of fingers between the gripping position and the release position,   wherein each finger of the plurality includes a nozzle which can be supplied by means of pressurized air and arranged in correspondence of the gripping area, the nozzle being configured for the ejection of air in a direction tangent with respect to the gripping area so as to set a depression in correspondence of the gripping area to hold a hollow glass article arranged in the gripping area itself,   the handling unit being characterized in that it includes at least two control units of the supply airflow of the nozzles, wherein each control unit of the airflow is configured to control at least one corresponding nozzle independently of the nozzles controlled by remaining control units of the airflow.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This U.S. Utility Patent Application claims priority to European Patent Application No. 6158971.8, filed on Mar. 7, 2016, and is incorporated herein by reference. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Technical Field 
         [0003]    The present invention relates to handling units for hollow glass articles, particularly finger type handling units. 
         [0004]    More in detail, the present invention will be developed with reference to a handling unit including: 
         [0005]    a plurality of fingers, each configured to engage a corresponding hollow glass article in correspondence of a gripping area and for dragging the article along a connection trajectory between a gripping position and a release position, 
         [0006]    a displacement mechanism of the plurality of fingers between the gripping position and release position, 
         [0007]    wherein each finger of the plurality includes a nozzle which can be supplied by means of pressurized air and arranged in correspondence of the gripping area, the nozzle being configured for ejecting air in a tangent direction with respect to the gripping area so as to set a depression in correspondence of the gripping area to fold a hollow glass article arranged in the gripping area itself. 
         [0008]    2. Related Art 
         [0009]    In the field of hollow glass articles forming machines wide use is made of handling units for hollow glass article of the finger type, that is including a plurality of fingers shaped to define a gripping area for hollow glass articles that have to be displaced along a connection trajectory between a pipping position and a release position (which correspond, for example, to the outlet of an upstream conveyor and to the inlet of a downstream conveyor arranged orthogonal or incident to one another). 
         [0010]    Although  FIG. 1  illustrates a handling unit according to the invention, the general structure is shared with known devices, so that it may be used as a reference for a general description of such devices. 
         [0011]    The handling unit  1  of  FIG. 1  includes a turntable  2  and a gripping unit  4 , which is configured to receive and drag the hollow glass articles from the gripping position to the release position. The displacement of the unit  4  is entrusted to a mechanism  6  installed on the turret  2  configured to drag the hollow glass articles along a curvilinear trajectory that connects the gripping and release positions. 
         [0012]    In this embodiment the mechanism  6  is of the articulated pentha-lateral type and includes a first rocker  7 A and a second rocker  7 B rotatable around a first axis of rotation A fixed in space, and a first and a second rods  7 C,  7 E articulated to one another and with respect to the rockers  7 A,  7 B, The rod  7 C is furthermore fixed to a header  7 D to which a crosspiece is connected which carries a plurality of fingers  10  of the gripping unit  4 . 
         [0013]    More in detail, the rocker  7 B has a first end articulated with respect to the rocker  7 A around the axis A, and a second end articulated to a first end of the rod  7 E around a second axis of rotation B parallel to the axis A. 
         [0014]    The rod  7 C has a first end articulated to a free end of the rocker  7 A in correspondence of a third axis of rotation C parallel to the axes A and B and has a second end (provided on a header  7 D) articulated to the rod  7 E in correspondence of a fourth axis of rotation D parallel to the axes A, B, C. The operation of such mechanism is per se known and will not be described further. 
         [0015]    It will be enough to mention that the rockers  7 A,  7 B are operated in rotation around the axis A between the (angular) gripping and release positions and the complex of the rods of the mechanism  6  provides for the displacement of the complex of fingers  10  from one position to the other. 
         [0016]    Each of the fingers  10  is made so as to define a gripping area for hollow glass articles which includes an angular element  12  on which a nozzle  14  is provided having a vertical axis (parallel to the axes A-D). Each nozzle  14  receives a pressurized air supply from a single pneumatic source and is configured for the ejection of air in a direction which is tangent with respect to the angular element  12  (that is in respect of the gripping area). In this way, a hollow glass article—for example a bottle—which during the movement from the gripping position to the release position abuts against the angular element  12  and against the finger  10  is held thanks to the depression created by the airflow sliding along the element  12 , thereby countering the centrifugal action resulting from the movement itself. 
         [0017]    The inventors have anyway observed that such a solution does not offer optimal performances in any condition of use, in so far as the ejection of air that is provided may result over- or under-dimensioned depending on the position of the hollow glass article (that is as a function of the finger  10  which is considered) with respect to the axis of rotation A, 
         [0018]    As a consequence, some hollow glass articles may escape from gripping because the depression that is created is insufficient in respect of the centripetal acceleration that develops in correspondence of the respective finger in the disparate points of the connection trajectory described thereby, or it is excessive and drags the article over the correct release position. 
       SUMMARY OF THE INVENTION 
       [0019]    The object of the present invention is to solve the aforementioned technical drawbacks. In particular, the object of the invention is to optimize the gripping of the hollow glass articles in a handling unit that uses a depression holding system for the articles, 
         [0020]    The object of the present invention is achieved by a handling unit for hollow glass articles having the features forming the subject of the appended claims, which form an integral part of the technical disclosure herein provided in relation to the invention. 
         [0021]    In particular, the object of the invention is achieved by a handling unit having all the features listed at the beginning of the present description, and further characterized in that it includes at least two control units of the supply airflow of the nozzle, wherein each control unit of the airflow is configured to control at least one corresponding nozzle independently of the nozzles controlled by remaining control units of the airflow. 
     
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         [0022]    The invention will now be described with reference to the attached figures, provided purely by way of non limiting example, wherein: 
           [0023]      FIG. 1  shows a handling unit according to the invention, 
           [0024]      FIGS. 2A, 2B, 2C, 2D  show corresponding embodiments of control units of the supply airflow of the nozzles that equip a handling unit according to the invention, 
           [0025]      FIGS. 3A, 3B, 3C, 3D  correspond substantially to  FIGS. 2A-2D  but show yet further embodiments. 
       
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0026]    With reference to  FIGS. 2A-2D , various embodiments of the handling unit I according to the invention will now be described, particularly various embodiments of supply circuits of a nozzles  14 . 
         [0027]    With reference to  FIG. 2A , reference number  16 A designates as a whole a supply circuit of the nozzle  14  according to a first embodiment of the invention. 
         [0028]    In particular, the circuit  16 A includes control units of the supply airflow of the nozzles  14  in equal number with respect to the nozzles  14  themselves. In the case in point, without this constituting any limitation whatsoever, the circuit  16 A includes four nozzles  14  and four control units of the airflow. 
         [0029]    Each control unit includes, arranged in series to one another, a two-way flow regulator valve RQ, and a solenoid valve SV having two ways and two positions (open-closed) arranged upstream of the flow regulator valve RQ. Each series connection comprising the valve RQ and the solenoid valve SV is arranged on a supply line F 1 , F 2 , F 3 , F 4  respectively, leading to a corresponding nozzle  14  and furthermore originating by branching off a circuit node that receives the supply from a pneumatic source S. 
         [0030]    With reference to  FIG. 2B , a second embodiment of the supply circuit is herein indicated by the reference  16 B. Circuit  16 B includes again a control unit of the airflow for each nozzle  14 . However, differently from circuit  16 A, each control unit of the airflow includes the sole valve RQ arranged on the corresponding supply line F 1 , F 2 , F 3 , and F 4 , respectively. 
         [0031]    In such case, furthermore, the lines F 1 -F 4  originate by branching off a circuit node that is arranged downstream of a single solenoid valve SV, upstream of which the pneumatic source S is located. Essentially, the solenoid valve SV that in the circuit  16 A is associated to each single nozzle  14 , is here in common to all the nozzles, being it arranged upstream of the bundle of flow regulation units. The fluid communication between the node from which the lines F 1 -F 4  originate is thus controlled by means of the solenoid valve SV. 
         [0032]    With reference to  FIG. 2C , a third embodiment of the supply circuit of the airflow to the nozzles  14  is indicated by the reference  16 C. The circuit  16 C substantially similar to the circuit  16 A, save for that in place of the flow regulator valves RQ pressure reducers PR are installed, preferably of the pneumatic driven type (downstream pressure) or electrically driven type, and in a position which is upstream of the corresponding solenoid valve SV (and not downstream as the valves RQ). 
         [0033]    This means that on each line F 1 , F 2 , F 3  and F 4  a series arrangement is observed of a pressure reducer PR and a solenoid valve SV, the latter downstream of the reducer PR. 
         [0034]    With reference to  FIG. 2D , a fourth embodiment of the supply circuit of the airflow to the nozzles  14  is indicated by the reference  16 D. The circuit  16 D is similar to the circuit  16 B, but again a replacement of the valves RQ with corresponding pressure reducers PR is provided. 
         [0035]    The operation of the unit  1 , and in particular of the respective circuit  16 A- 16 D, is the following. 
         [0036]    In case of the circuit  16 A, each control unit allows to modulate the supply of air to the corresponding nozzle  14  by varying the flow thereof thanks to the valves RQ, and possibly opting for the exclusion thereof by way of the solenoid valves SV. Each control unit controls the corresponding nozzle completely independently of the control operated by the other units on the respective nozzles, albeit receiving airflow from the same source S. 
         [0037]    Similar considerations apply in respect of the circuit  16 C, wherein the airflow going to each nozzle  14 , may be controlled independently by way of the pressure reducers PR (in such case the flow reduction will be depending on the calibration pressure of the reducer PR), and wherein it is possible to exclude one or more nozzles  14  independently by operating the corresponding solenoid valve SV. 
         [0038]    In case of the circuits  16 B and  16 D, flow modulation takes place with the same modalities as the circuits  16 A and  16 C (respectively), that is, completely independently for each nozzle  14 , but the exclusion of the nozzles  14  is only available in a centralized fashion by way of the valve SV, so that it is not possible to decide for the selective exclusion (which corresponds to the shutdown of the airflow). 
         [0039]    The flow modulation criteria may be multiple, and in general they are based on the values of the centripetal acceleration acting on each hollow glass article engaged in a corresponding finger  10 . The modulation is thus provided with the aim of creating flow conditions of the air from each nozzle  14  that result in a depression proportional to the entity of the centrifugal actions on the hollow glass article dragged by the corresponding finger  10 . 
         [0040]    With reference to  FIGS. 3A-3D , further embodiments of the supply circuit of the airflow to the nozzles  14  will now be described by means of which it is possible to operate a different type of control of the nozzles  14 . 
         [0041]    The circuits of the  FIGS. 3A-3D  are characterized all by having control units of the airflow that control pairs of nozzles  14 . 
         [0042]    With reference to  FIG. 3A , a fifth embodiment of the supply circuit of the airflow is indicated by the reference ISA, and includes a first circuit branch FA and a second circuit branch PB, both branching off the source Sin correspondence of the circuit node. 
         [0043]    On each branch FA, FB the two-way flow regulator valve RQ and, upstream thereof, the solenoid valve SV are arranged, connected in series with one another. 
         [0044]    Downstream of the valve RQ is located a further circuit node from which two supply lines (F 1 ′, F 2 ′ for the branch FA and F 3 ′, F 4 ′ for the branch FB) branch off, each leading to a corresponding nozzle  14 . 
         [0045]    With reference to  FIG. 3B , a sixth embodiment of the supply circuit of the airflow is indicated by the reference  18 B. The circuit  18 B differs from the circuit  18 A in that the control units of the airflow on the branches FA and FB include the sole flow regulator valves RQ (one for each branch). For this reason, the node from which the lines F 1 ′ and F 2 ′, F 3 ′ and F 4 ′ branch off is located downstream of the flow regulator valve RQ of each unit. 
         [0046]    Upstream of the circuit node from which the branches FA and FB branch off, a single solenoid valve SV is arranged, upstream of which the source S is located, The fluid communication between the nodes from which the branches FA and FB branch off is thus regulated by means of the solenoid valve SV. 
         [0047]    With reference to  FIG. 3C , a seventh embodiment of the supply circuit of the airflow is indicated by the reference  18 C. The circuit  18 C is identical to the circuit  18 A, save for the replacement of the flow regulator valves RQ with the pressure reducers PR. 
         [0048]    Last, with reference to  FIG. 3D , an eight embodiment of the supply circuit of the airflow is indicated by the reference  1811  The circuit  181  is identical to the circuit  18 B, save for the replacement of the flow regulator valves RQ with the pressure reducers PR. 
         [0049]    The operation of the unit  1  equipped with supply circuits  18 A- 18 D is the following. 
         [0050]    In each of the circuits  18 A- 18 D the pairs of nozzles  14  supplied by the lines F 1 ′, F 2 ′ leading to the branch FA may be controlled independently of the pairs of nozzles  14  supplied by the lines F 3 ′, F 4 ′ leading to the branch FB. In particular, in case of the circuits  18 A and  18 C the airflow supplied to each pair 
         [0051]    of nozzles may be regulated independently from the other pair of nozzles (by way of the valves RQ or the reducers RP), and each pair may be excluded independently of the other pair by way of closure of the corresponding solenoid valve SV. It is not possible, however, the separate regulation of the nozzles  14  within each single pair. 
         [0052]    Similar considerations apply as far as the units  1  equipped with a circuits  18 B and  18 D are concerned, with the sole difference lying in the fact that the exclusion of the nozzles  14  takes place in a centralized fashion by means of the switching of the solenoid valve SV upstream of the branches FA and FB in the closed position. It is not possible to separate the excluded pairs, while it remains available the possibility to control the flow independently for each pair of nozzles. 
         [0053]    Following the same rationale, that is by placing the solenoid valves SV alternatively upstream or downstream of the bundle of supply lines, further operational combinations may be achieved, wherein, fir example, a control unit for the airflow is associated to three nozzles  14  and a second control unit of the airflow is associated to a one and last nozzle  14 . 
         [0054]    Whatever the control combination chosen, the main advantage with respect to known devices consist in the possibility to regulate the airflow for the nozzles  14  as a function of the actual request dictated by the circumstances, in particular by the centripetal acceleration that rises during the rotary movement of the fingers  10  operated by the mechanism  6 . 
         [0055]    Furthermore, it should be observed how the circuits  16 A- 16 D and  18 A- 18 D may be provided both by way of external pipings, and by way of passageways provided directly inside the components constituting the unit  1 . In this latter case ( FIG. 4 ), the flow regulator valves or the pressure reducers RP may be coupled to or replaced by grub screw chokes T engaged into the crosspiece  8 , particularly in positions intercepting flow channels leading to corresponding nozzles  14  (for example in positions corresponding to the lines F 1 -F 4  or F 1 ′-F 4 ′, or to the branches FA-FB provided into the crosspiece  8 ) thereby constituting themselves part of the control units of the supply airflow of the nozzles  14 . The chokes T may be operated manually or by way of electrical or pneumatic actuators. 
         [0056]    It will be anyway appreciated that, independently of the chosen combination, according to the invention at least two control units of the airflow are envisaged which control, each, at least one corresponding nozzle independently of the nozzles controlled by the remaining control units of the airflow. In this way, with reference to a handling unit having four fingers  10 , control logics may be implemented having four independent nozzles ( 1 - 1 - 1 - 1 ), independent pairs of nozzles ( 2 - 2 ), or asymmetrical logics ( 3 - 1 ;  1 - 3 ), wherein three nozzles are controlled jointly and one nozzle is independently controlled. 
         [0057]    Of course, the constructional details and the embodiments may be widely varied with respect to what described and shown herein without by this departing from the scope of protection of the present invention, as defined by the appended claims. 
         [0058]    For example, embodiments are possible wherein on each line F 1 , F 2 , F 3 , F 4  or on each branch FA, FB a control unit of the supply airflow of the nozzles  14  is installed consisting in a two way-two position solenoid valve (open position/closed position, similar to the valve SV) of the proportional type, by which it is possible to serve the functions of the valves RQ and SV (or PR and SV) in combination. In such case the embodiments of the circuits  2 B,  2 D and  3 B,  3 D may be deemed as not preferred in so far as the single proportional solenoid valves will be anyway capable of serving the function of exclusion of the corresponding nozzle(s).