MX2008009722A - Unit for applying opening devices to packages of pourable food products - Google Patents

Abstract

A unit (1, 1') for applyingopening devices (2, 2') to packages (3) of pourable food products, the unit (1, 1') having first conveying means (8, 8') for feeding the opening devices (2, 2') successively along a first path (P1, P1');second conveying means (9) for feeding the packages (3) successively along a second path (P2);and transfer means (10) for transferring the opening devices (2, 2') from the first path (P1, P1') to the second path (P2), and in turn having a wheel (18) rotating about an axis (A), and a number of gripping members (19, 19') carried by the wheel (18) and for receiving respective opening devices (2, 2') from the first conveying means (8, 8') and transferring them to the second path (P2) by rotation of the wheel (18);the transfer means (10) also having connecting means (20) for connecting the gripping members (19, 19') movably to the wheel (18), and cam guide means (21) for altering the position of each gripping member (19, 19') with respect to the wheel (18) as the wheel (18) rotates.

Description

UNIT FOR APPLYING OPENING DEVICES TO PACKS OF FOOD SAFE PRODUCTS Field of the invention The present invention relates to a unit for applying opening devices to packages of pourable food products. BACKGROUND OF THE INVENTION As is known, many pourable food products, such as fruit juice, UHT milk (treated at ultra high temperature, for its acronym in English), wine, tomato sauce, etc., are sold in sealed packages made of sterilized packaging material. A typical example of this type of package is the parallelepiped-shaped package for liquid or pourable food products known as sterilized Tetra Brik (registered trademark), which is made by folding and sealing laminated band packaging material. The packaging material has a multilayer structure which substantially comprises a base layer for stiffness and strength, which may comprise a layer of fibrous material, for example paper, or polypropylene material filled with ore, and a number of layers of material of heat seal plastic, for example polyethylene film, covering both sides of the base layer. In the case of sterilized packages for products Ref. 193091 for prolonged storage, such as UHT milk, the packaging material also comprises a layer of gas and light barrier material, for example aluminum foil or ethyl vinyl alcohol film (EVOH, for its acronym in English) , which is superposed on a layer of heat seal plastic material, and in turn covered with another layer of heat seal plastic material forming the inside face of the package that eventually contacts the food product. As is known, packages of this kind are produced in fully automatic packaging machines in which a continuous tube of the web packaging material is formed; the band of packaging material is sterilized in the packaging machine, for example by applying a chemical sterilizing agent, such with a hydrogen peroxide solution, which, once the sterilization is complete, is removed from the material surfaces packaging, for example evaporated by heat; and the band of packaging material thus sterilized is kept in a sterile, closed environment, and is folded and sealed longitudinally to form a vertical tube. The tube is filled with the sterilized or sterile processed food product, and is sealed and subsequently cut along equally spaced cross sections to form pillow packs, which are then mechanically folded to form substantially parallelepiped shaped packages, respectively terminated. Alternatively, the packaging material can be cut into blanks, which are formed into packages in forming spindles, and the packages are filled with the food product and sealed. An example of this type of package is the so-called "plastic coating" package known by the trademark Tetra Rex (registered trademark). Once formed, the above packages can be subjected to further processing, such as the application of a resealable opening device. Presently, the most commonly traded aperture devices comprise a frame defining an opening for pouring and fitting over an orifice or a pierceable or removable portion of an upper package wall; and a lid hinged or screwed to the frame, which is removable to open the package. Alternatively, other types of opening devices, for example sliding opening, are also known to be used. The pierceable portion of the package can be defined, for example, by a hole so-called "pre-laminate", ie an orifice formed in the base layer of the packaging material before covering the base layer with the layer of barrier material, which is therefore a whole and closes the hole to ensure sealing, sterilized sealing, while still easily pierceable. In the case of sterilized packaging machines, the described opening devices, once they are formed, are normally applied directly to the packages by in-line application units located in the 3 'direction of the packaging machine. The application of the opening devices, for example by heat sealing or bonding, involves several preliminary operations both on the packages and on the opening devices themselves. More specifically, when the opening devices are applied by heat sealing, both the outer heat seal layer for the packaging material on the holes or perforable portions of the packages and the opening devices partially melt or soften locally by preheating . Once applied to the respective packages, the opening devices must be held firmly in the packages enough for the contact materials to cool and allow adhesion. Similarly, when the opening devices are glued, one or both of the gluing parts must be coated with adhesive, and the parts must be held firmly in contact with each other sufficiently to allow adhesion. It is known that the application units substantially comprise two, for example, chain, conveyors to successively feed the opening devices and the packages respectively along separate infinite paths having respective adjacent parallel portions, along which they are pasted. each opening device to the respective package. Alternatively, the application units are known, for example, as described in EP-A-1462370, which comprise a first linear path conveyor for feeding a succession of packets along a first route, preferably straight; a second linear path conveyor for feeding one of succession of opening devices along a second straight path extending parallel and in the direction opposite to the first path; and a carousel conveyor operated by step to feed the opening devices of a raising station, coincident with one of the stopping stations on the second conveyor, to an application station, wherein the opening devices are applied to the packages respective, and that it coincides with one of the stop stations on the first conveyor. More specifically, the carousel conveyor feeds the opening devices along a circular path, with a vertical axis, through a number of intermediate work stations, where the opening devices are stopped and subjected to various operations preliminaries before applying to the respective packages. In both c, the versatility of known application units is just poor, because, for example, the feed rate of the opening device to the application unit necessarily has to match the pack feed rate to the unit. Which means that the speed of the application unit is dictated by the longest operation performed on both opening devices and packages. In addition, both known types of unit are extremely bulky, and have several parts that are accessible only with difficulty by the operator. BRIEF DESCRIPTION OF THE INVENTION It is an object of the present invention to provide a unit for applying opening devices to pourable food product packages, designed to provide a direct, low cost solution to the aforementioned disadvantages typically associated with known units. In accordance with the present invention, there is provided a unit for applying opening devices to pourable food product packages, comprising: first conveying means for feeding the opening devices successively along a first route; second conveying means for feeding the packets successively along a second route; and transfer means for transferring the opening devices of a localized rise station along the first route, to an application station for applying the opening devices to the respective packages and located along the second route; the transfer means comprising a wheel rotating on an axis, and at least one grip member carried by the wheel and for receiving an opening device at a moment from the first means of transportation, and transferring it to the second route when turning the wheel; characterized in that the transfer means also comprise connecting means for connecting the grip member movably to the wheel; and guide means for altering the position of the gripping member with respect to the wheel as the wheel rotates. BRIEF DESCRIPTION OF THE DRAWINGS Two preferred, non-limiting embodiments of the present invention will be described by way of example with reference to the appended figures, wherein: Figure 1 shows a front view, with parts removed for clarity, of a compliance unit with the present invention for applying opening devices to packages of pourable food products; Figure 2 shows a first view on a larger scale in perspective of a gripping member of the unit of Figure 1 for feeding a respective opening device to the application area to a respective package; Figure 3 shows a second perspective view of the grip member of Figure 2; Figure 4 shows a view in smaller scale in perspective of a drive mechanism for operating the grip member of Figure 2 and 3; Figure 5 shows a side view, with parts removed for clarity, of a portion of the unit of Figure 1; Figure 6 shows a perspective view of a pressure device of the unit of Figure 1 to press the opening devices to full adhesion; Figure 7 shows a side view of a pressure member of the device of Figure 6; Figure 8 shows the same view as in Figure 1, of an alternative embodiment of the unit according to the present invention; Figure 9 shows a view in larger scale in perspective of a gripping member of the unit of Figure 8 for feeding a respective opening device to the application area to a respective package; Figure 10 shows a side view, with parts removed for clarity, of a portion of the unit of Figure 8; Figure 11 shows a side view of a drive mechanism for operating the grip member of Figure 9. Detailed description of the invention Number 1 in Figure 1 indicates as a whole a unit for applying opening devices 2 to sealed packages 3 of pourable food products. The packages 3 are produced in the 5 'direction of unit 1, as previously described, of sheet packaging material comprising a base layer, for example of fibrous material such as cardboard, or of mineral-filled polypropylene material; and a number of layers of heat seal plastic material, for example polyethylene film, covering both sides of the base layer. In the case of sterilized packages 3 for prolonged storage products, such as UHT milk, the packaging material also comprises a layer of gas and light barrier material, for example aluminum foil or ethyl vinyl alcohol film (EVOH) , which is superposed on a layer of heat seal plastic material, and in turn covered with another layer of heat seal plastic material forming the inside face of the package 3 which eventually contacts the food product. Each package 3, which has a substantially parallelepiped shape in the example shown, has, on an end wall 4, an opening or a pierceable or removable portion (not shown), which is covered externally by a respective opening device 2 applied to the package 3 per unit 1. More specifically, the opening devices 2 in Figures 1, 2, 3, 5 and 7 are screw types made of plastic material, and each comprises in a known manner an annular, externally threaded frame. , which is fixed to the wall 4 of a respective package 3 and defines a direct opening 6 through which the food product is poured; and an internally threaded cap 7 screwed to the frame 5 to close the opening 6. The opening devices 2 may also comprise, in known manner, means (not shown) for piercing the pierceable portion or removing the removable portion of the package 3 when it is opened the package. With reference to Figure 1, unit 1 substantially comprises a first linear conveyor 8, known and only schematically shown, for feeding a succession of opening devices 2 along a straight horizontal route Pi; a second linear conveyor 9, also known and only schematically shown, for feeding a succession of packages 3 along a straight horizontal route P2 parallel and in the opposite direction to the route Pi in the example shown; and a transfer conveyor wheel 10 for feeding opening devices 2 of a lift station 11 located along the route P1 # to an application station 12 located along the route P2 and to apply opening devices 2 to respective packages 3. The conveyor 8 defines, at least near the rise station 11, a horizontal transportation surface 13, in which the opening devices 2 are placed with covers 7 facing downwards towards the conveyor wheel 10. While traveling along the conveyor 8, the opening devices 2 are coated on the face facing upward, ie opposite the side facing the conveyor wheel 10, with adhesive, preferably by means of cannons (not shown) located along the route Pi. The conveyor 9 is located under the conveyor 8, and defines, at least near the application station 12, a horizontal transportation surface 14, in which the packages 3 have respective walls 4, to which eventually opening devices are applied 2, placed horizontally at the top, facing the conveyor wheel 10. In the example shown, the spacing Di of the opening devices 2 along the conveyor 8 is different from, and more specifically less than, the spacing of D2. of packages 3 along the conveyor 9; the term "spacing" which is used in the sense of the distance between corresponding points of two adjacent opening devices 2 or two adjacent packages 3. The transport wheel 10 continuously rotates on a horizontal axis A perpendicular to the routes Pi and P2, and it feeds the opening devices 2 along a curved path P3 of the rising station 11 to the application station 12. The conveyor wheel 10 substantially comprises a wheel 18 of the axis A; and a number of gripping members 19 equally spaced on the axis A and adjusted towards and projecting radially from the wheel 18. The unit 1 advantageously also comprises a number of connection assemblies 20 for connecting respective gripping members 19 in a movable manner to wheel 18; and cam guide means 21 for altering the position of each grip member 19 with respect to the wheel 18 while the wheel 18 rotates. The spacing of the opening devices 2 along the P3 path in that way can be adjusted as required to adapt it to the specific operations requirements to be performed on opening devices 2 (as explained in detail below), and for make it equal to the spacing D2 of the packages 3 in the application station 12. With reference to Figures 1, 2, 3, 5 and 6, the connection assemblies 20 comprise a number of guide members 23 extending radially over the axis A and fixed to and projecting towards an end surface 24 of the wheel 18; and the number of sliding members 25 adjusted in the form of sliding to respective guide members 23, and each supporting a respective grasping member 19. More specifically, the wheel 18 has a central disc-shaped portion 18a, of which a number of radial projections 18b are projected peripherally, each adjusted with a respective guide member 23. Each gripper member 19 fits a plate 26, which is hinged to the respective slide member 25, on the opposite side respective guide member 23, and on a respective axis B parallel to axis A and perpendicular to plate 26.

Each gripping member 19 can therefore be transferred with respect to the wheel 18 in a given radial direction with respect to the axis A, and can oscillate with respect to the wheel 18 on a respective axis B perpendicular to and incident with the radial direction. As shown in Figure 1, the guide means 21 comprises two curved fixed cams 27, 28 which extend uniformly on the axis A and which cooperate with the respective inactive cam follower rollers 29, 30 fitted to the sliding member 25. on the plate 26, respectively, of the connection assembly 20 of each gripping member 19. More specifically, the cams 27, 28 are defined by respective delineated grooves formed in a fixed vertical wall 33 located behind the wheel 18 with reference to the Figure 1, or, more specifically, placed towards an end surface of the opposite end surface 24 of the wheel 18. All parts of the cam 28 are positioned radially outwardly of the cam 27. The cam 27 controls the radial position of the gripping members 19 with respect to the axis A while the wheel 18 rotates, while the cam 28 controls the orientation of the gripping members 19, and therefore of opening devices 2, with re the radius of the wheel 18 to which they are fixed.

As shown in Figure 1, the gripping members 19, and therefore the opening devices 2, change position with respect to the wheel 18 while the wheel 18 rotates, thereby altering its peripheral speed. Whose change in position between the rise station 11 and the application station 12 is provided to adapt the spacing of opening devices 2 to that of (D2) of the packages 3. With reference to Figures 1, 2, 3 and 5 , each grip member 19 is fixed to the respective plate 26 by a support frame 34 projecting from the plate 26 on the side opposite the respective slip member 25. More specifically, each frame 34 comprises a main body 35 having substantially L in a plane perpendicular to the respective plate 26, and is defined by a first plate portion 36 fixed parallel to and against the plate 26, and by a second plate portion 37 projecting perpendicularly from the plate portion 36 , on the side opposite the respective sliding member 25. Each frame 34 also comprises two clasps 38 extending from a free end of the relative plate portion 37 in a direction parallel to and oriented towards the relative plate portion 36; and a clamping body 39 that integrally fits with the relative gripping member 19, is slidably fitted to the fasteners 38, and is elastically loaded, by coaxial coil springs 40 with respective clasps 38, in a first, removed, operative position. , ie at a minimum radial distance of the axis A with reference to the specific radial position occupied by the relative sliding member 25 along the relative guide member 23. More specifically, the holding body 39 of each frame 34 comprises a portion of main plate 43 extending parallel to relative plate 26 and to plate portion 36 of relative main body 35, and from which relative gripping member 19 projects on the side opposite that adjacent to the relative plate portion 37; and an appendix 44 extending perpendicularly from the end of the main portion 43 adjacent the plate portion 37, and defining two direct holes slidably engaged by respective clasps 38. As shown in Figures 2 and 3, the clasps 38 of each frame 34 extend through the relative appendix 44, and have respective portions 46 projecting from the appendix 44 and facing the relative main portion 43. Each portion 46 is externally wrapped with a respective spring 40 interposed between the appendix relative 44 and an annular end shoulder 47 of the portion 46. A cam follower roll 48 fits and projects from the appendix 44 of each frame 34, on the opposite side to the relative main portion 43, and cooperates in the form of winding as in two fixed cams 40 (shown in Figures 2 and 5) located respectively in stations 11 and 12. With reference to Figures 2 and 5 , the cams 50 are located on the opposite side of the wheel 18 to the vertical wall 33 that supports cams 28, 29, and each one comprises an upper portion 53 that projects radially outwardly with respect to the axis A, and of which extend respective opposite inclined ramp portions 54, 55. With reference to the direction of rotation of the wheel 18, the ramp portion 54 of each cam 50 is inclined upward towards the relative upper portion 53, and the ramp portion 55 is inclines downwardly of the upper portion 53. Each cam follower roll 48 rolls along each cam 50 relative to the grip member 19 which is moved first from the first removed operative position to a second operative position forward was, reached in the upper portion 53 of cam 50, and then it returns to its original position. In the second forward operative position, each grip member 19 is located at a maximum radial distance from the axis A with reference to the radial position occupied by the relative slide member 25 along the relative guide member 23. The rise and release of opening devices 2 by gripping members 19 are respectively made in the second operative position. With particular reference to Figures 2 and 3, each gripping member 19 comprises a support body 56 fixed to and projecting from the end of the main portion 43 of the relative clamping body 39 opposite the end of which the relative appendage extends. 44; and three jaws 57, 58, 59 projecting from the radially outer side of the support body 56 with respect to the axis A, and for gripping a relative opening device 2. One of the jaws (57) is fixed to a body of support 56, while the other two (58, 59) oscillate on respective axes C perpendicular to the axis A and the plate portion 37 of the relative frame 34. As shown in Figure 3, when the relative opening device 2 is gripped, the jaws 57, 58, 59 of each gripping member 19 are equally spaced angularly over the opening device 2. More specifically, the jaws 58, 59 of each gripping member 19 are elastically loaded in a closed position which retains the relative opening device 2 between them and against fixed jaw 57, and are selectively movable, in stations 11 and 12, in an open position in which they are separated to allow coupling and release of the opening device 2. The movements of the jaws 58, 59 of each grip member 19 are controlled by a lever and cam drive mechanism 50 shown in detail in Figures 3 and 4. The drive mechanism 60 comprises two snap fasteners 61a, 61b axially fixed and rotatable through respective direct holes in the support body 56 of the relative gripping member 19, and the opposite ends of which, projecting from the support body 56, are respectively fixed with respective jaws 58, 59 and respective sector gears 62, 63 that mesh with each other. One of the sector gears (62) defines an end portion of a respective lever 64, the other end portion which is adjusted with an idle cam follower roller 65 which co-operates with two fixed cams 66 ( shown in Figures 3 and 5) located respectively in stations 11 and 12. The cams 66 are located on the opposite side of the wheel 18 to the vertical wall 33 that supports cams 28, 29, and each one comprises an upper portion 67 that it projects towards the wheel 18 and from which respective opposite inclined ramp portions 68, 69 extend. With reference to the direction of rotation of the wheel 18, the ramp portion 68 of each cam 66 slopes downwardly toward the portion relative top 67, and the ramp portion 69 slopes downwardly from the upper portion 67. While each cam follower roller 65 rolls along each cam 66, the relative lever 64 is first rotated about the axis of the rear snapper. Livative 61a, in that way moves the jaws 58, 59 simultaneously in the open position, reached in the upper portion 67, and then rotates in the opposite direction to restore the jaws 58, 59 to the closed position. With reference to Figures 5, 6 and 7 the unit 1 also comprises a pressure device 70 which acts on the opening devices 2, from the application station 12 and along a portion of the route P2, to hold them firmly in place. the respective packages 3 until full adhesion. The pressure device 70 comprises a known conveyor 71 (shown only in part) for feeding a number of pressure members 72 along a straight path P4 parallel to and oriented to the route P2 and interposed between the route P2 and the route Pi . The pressure members 72 are spaced at the same spacing as the spacing D2 of the packages 3, and exert pressure on respective opening devices 2 as soon as they are applied to the packages 3. Each pressure member 72 substantially comprises an integral pin 73 with the conveyor 71; and two rocking arm levers 74, 75 hinged to the clasp 73 and comprising respective pairs of arms 76, 77 and 78, 79 arranged in the form of an X on the clasp 73. More specifically, with reference to the direction travel of the pressure members 72 along the route P4, the arms 76, 78, located in the 5 'direction of the relative clip 73, of levers 74, 75 of each pressure member 72 define, respectively, a finger of pressure 80 acting on the relative opening device 2, and a cam follower roller 81 cooperating in a coiled manner with a relative fixed cam 82; while the free ends of the arms 77, 79, located in the 3 'direction of the relative clasp 73, of levers 74, 75 define respective seating surfaces for a coil spring 83 to maintain the relative cam follower roller 81 in contact with the 82. As shown in Figure 6, the cam 82 comprises a main portion 84 extending from the application station 12, and which is straight and parallel to the routes P2 and P4, and is located at such a distance from the opening devices 2, applied to respective packages 3, to carry the pressing fingers 80 in contact with the opening devices 2. The cam 82 also comprises, in direction 5 'of the application station 12, a ramp portion 85 which slopes down towards the packages 3 to move the pressing fingers 80 of the pressing members 72 from a completely separate position from the packages 3, to the position contacting the opening devices 2 applied sa the packages 3. The operation of unit 1, which is already partly obvious from the above description, will now be described with reference to an opening device 2, and from the instant in which the opening device 2, already coated with adhesive, it travels through the raising station 11. The gripping member 19 for receiving the opening device 2 is set to the best lifting position by the cam follower rollers 29, 30 which interact with respective cams 27, 28, and is also established by the cam 27 to the desired radial position, with respect to the axis A, which corresponds to a specific peripheral speed. The peripheral speed of the gripping members 19 in the lifting station 11 is preferably greater than the travel speed of the opening devices 2, to minimize the impact between the gripping members 19 and the opening devices 2. When reaching the rising position 11, grip member 19 moves toward the path Pi of opening devices 2 in the second forward operating position by its own cam follower roll 48 which interacts with relative cam 50, and jaws 58, 59 they rotate in the open position by the cam follower roller 65 of the lever 64 which interacts with the relative cam 66. Then, the jaws 58, 59 of the grip member 19 close on the relative aperture device 2, and the member grip 19 retracts from the Pi path back in the first removed operative position. The position and travel speed of the grip member 19 along the route P3 are determined by the cam follower rolls 28, 29 interacting with cams 27, 28, and along the P3 path, the spacing of the opening devices 2 is made equal to the spacing D2 of the packages 3. Near the application station 12, the cam follower roller 48 of the grip member 19 interacts with the relative cam 50 to move the grip member 19 of return in the second forward operating position; and, at the same time, the cam follower roller 65 of the lever 64 interacts with the relative cam 66 to rotate the jaws 58, 59 in the open position to release the opening device 2 once it is deposited in the respective package 3. A relative pressure member 72 is moved, by its cam follower roller 81 which interacts with the cam 82, in the position in which the pressing finger 80 is brought into contact with the adventure device 2 to hold it in place. the respective package 3 until adhesion. By means of a few direct alterations described below, unit 1 can be converted to a unit 1 '(Figures 8-11) designed to operate with 2' opening devices of a different type and fed differently to unit 1 '. As shown in Figures 8 and 9, the opening devices 2 'are flat and substantially rectangular, made of plastic material, and hinged together. Each opening device 2 'comprises in a known manner a surrounding frame 5' (only partially shown) which is fixed to the wall 4 of a respective package 3 and defines a direct opening (not shown) through which the food product is poured.; and a cover 7 'hingedly attached to the frame 5' to close the opening. The opening devices 2 'are fed to the unit 1' along a circular path Pi 'by a rotary conveyor 8', operated by step in the example shown; they are spaced with a spacing Di 'different from spacing D2 of packets 3; and, to stick to the packages 3, they require a relatively small amount of adhesive when compared to that of the opening devices 2, and therefore can be easily coated with adhesive using a direct coating roller 90.

By virtue of the peripheral speed of the opening devices 2 'on the wheel 18 which is controllable by the cams 27, 28, a portion of the route P3 can advantageously be formed along which the opening devices 2' travel to. a suitable constant speed that allows the opening devices 2 'to be coated with adhesive when sliding on the coating roller 90, which is therefore located along the wheel 18, immediately in the direction 5' from the application station 12 The unit 1 is therefore substantially converted to the unit 1 'by installing the coating roller 90 along the route P3, by replacing the grip members 19 with grip members 19' designed to interact with opening devices. 2 ', and by replacing drive mechanisms 60 with appropriate drive mechanisms 60'. As shown in Figures 8-11, each grip member 19 'substantially differs from the relative grip member 19 in comprising two movable jaws 91, 92 for gripping opposite sides of the relative aperture device 2'. More specifically, the gripping member 19 'comprises a substantially parallelepiped-shaped support body 93 which, similar to the support body 56, is fixed to and projects from the main portion 43 of the relative clamping body 39, on the opposite side to that from which the relative appendix 44 is projected. The jaws 91, 92 are defined by elongated bodies extending along opposite sides of the support body 93, and comprising first end portions 94 adjacent to the relative appendix 44 and joined together. by hinge to the support body 93 on respective axes D parallel to the plate portion 37 of the relative frame 34 and perpendicular to the axis A; and second opposite end portions 95 further located radially outwardly with respect to the axis A, and substantially in the form of curved tips with their concavities which are oriented to grip and retain a relative opening device 2 '. As shown in particular in Figure 11, the jaws 91, 92 are elastically loaded towards each other, to define a closed position, by a cylindrical helical spring 96 extending through the support body 93 in a direction parallel to the axis. A. The end portions 94 of the jaws 91, 92 define respective sector gears that mesh with each other, and one of which (defined by the jaw 91) integrally connects to a lever arm 97 extending from the relative axis D, in the opposite direction to the relative jaw 91, and is adjusted with a cam follower roller 98 which operates in the form of winding with two fixed cams 66 ', identical with cams 66, to produce, in stations respective 11 and 12, a rotational movement of separation of the jaws 91, 92 on respective axes D in an open position that allows coupling and release of the relative opening device 2 '. The unit 1 'operates in exactly the same way as unit 1, the only difference being that the opening devices 2' slide over, and are coated with adhesive by, coating roller 90 in the 5 'direction of the application station. 12. The advantages of units 1, 1 'in accordance with the present invention will be clarified from the above description. In particular, units 1, 1 'are highly versatile and, with only minor alterations, can operate with different types of opening devices (2, 2'). In fact, given the possibility of adjusting the speed of gripping members 19, 19 'while the wheel 18 rotates, the spacings Di and D2 with which the opening devices 2 and the packages 3 are fed to the wheel conveyor 10 in no way they are dependent, and any of the necessary operations can be performed while the opening devices 2, 2 'are transported on the conveyor wheel 10.

The non-dependence of the spacings Di and D2 with which the opening devices 2, 2 'and packages 3 are fed to the conveyor wheel 10, together with continuous operation of the conveyor wheel 10, allows high output speeds to be achieved. In addition, controlling the trajectory and speed of the gripping members 19, 19 'by means of cams 27, 28 minimizes the impact between opening devices 2, 2' and relative gripping members 19, 19 'in the lifting station 11; for which purpose, the peripheral speed of the gripping members 19, 19 'in the station 11 is preferably greater than the speed at which the opening devices 2, 2' are fed to the station 11. Finally, the positioning of the wheel 18 vertically, that is to say with the axis A placed horizontally, minimizes the space occupied by the unit 1, 1 'as a whole, and makes the operator access all the component parts of the unit 1, 1' easier. Clearly, the changes can be made to units 1, 1 'as described and illustrated herein, however, without departing from the protective scope defined in the appended claims. In particular, the opening devices 2, 2 'can be heat sealed to respective packages 3, in which case, the adhesive coating operations will be replaced by heat operations performed, for example, in the 5' direction from the wheel 18 or along the route P3 produced jointly by rotation of the wheel 18 and the guide action of the cams 27, 28. It is noted that in relation to this date, the best method known by the applicant to implement said cited invention, is that which is clear from the present description of the invention.

Claims (16)

1. CLAIMS Having described the invention as above, the content of the following claims is claimed as property: 1. A unit for applying opening devices to packages of pourable food products, characterized in that it comprises: first means of transportation to feed the opening devices successively along a first route; second conveying means for feeding the packets successively along a second route; and transfer means for transferring the opening devices from a rise station located along the first route, to an application station for applying the opening devices to the respective packages and located along the second route; the transfer means comprising a wheel rotating on an axis, and at least one grip member carried by the wheel and for receiving an opening device at a time from the first means of transportation, and transferring it to the second route by rotation of the wheel; wherein the transfer means also comprise connecting means for connecting the grip member movably to the wheel; and guide means for altering the position of the gripping member with respect to the wheel as the wheel rotates.
2. 2. - A unit according to claim 1, characterized in that the connecting means comprise guide and sliding means interposed between the wheel and the gripper member.
3. 3. - A unit according to claim 2, characterized in that the guide and slide means comprise at least one guide member fixed to the wheel radially with respect to the axis; and at least one sliding member fitted slidably to the guide member.
4. 4. A unit according to claim 3, characterized in that the connecting means comprise articulation means between the gripping member and the sliding member to allow oscillation of the gripping member on an incident hinge axis with and diagonally to the radial direction of movement of the sliding member.
5. 5. - A unit according to claim 4, characterized in that the guide means comprise cam means for controlling, while the wheel is rotating, the movements of the gripping member radially with respect to the axis of the wheel, and on the axis of hinge.
6. 6. - A unit according to claim 5, characterized in that the cam means comprise two cams that extend uniformly on the axis of the wheel; a first of the cams that is coupled in the form of a winding by an integral cam follower with the sliding member; and a second of the cams that is coupled in the form of winding by an integral cam follower with a component part, carried by the gripping member, of the articulation means.
7. 7. - A unit according to claim 6, characterized in that the first and second cam are transported by means of fixed supports.
8. 8. - A unit according to any of claims 6 or 7, characterized in that the gripping member is connected to the component part of. the means of articulation by a support frame; and wherein the support frame comprises a first portion fixed to the component part, and a second portion fixed to the grip member and movable with respect to the first portion to increase or decrease the distance between the grip member and the axis of engagement. the wheel in relation to the specific position occupied by the sliding member along the guide member.
9. 9. - A unit according to claim 8, characterized in that the support frame comprises elastic means interposed between the first and the second portion to normally maintain the first and second portions in a predetermined relative position corresponding to the minimum distance of the wheel axis in relation to a specific position occupied by the sliding member along the guide member; and wherein additional camming means are provided to increase the distance, as opposed to the elastic means, in the raising station and the application station.
10. 10. A unit according to any of claims 8 or 9, characterized in that the gripping member comprises a main body integral with the second portion of the support frame; and at least two jaws that are movably connected to the main body, are elastically loaded towards each other to define a closed position encompassing a relative opening device, and are movable, in the up and application stations and by a mechanism of lever and cam drive, in an open position that allows coupling and release of the opening device.
11. 11. A unit according to any of the preceding claims, characterized in that the gripping member is selectable from at least two types of gripping members designed to operate with different types of opening devices.
12. 12. - A unit according to any of the preceding claims, characterized in that it also comprises pressure means that exert contact pressure between the opening devices and the packages from the application station and along at least a portion of the second route.
13. 13. - A unit according to any of claims 4 to 12, characterized in that it comprises a number of grip members connected by the respective articulation members to the respective sliding means, which in turn are connected in the form of sliding to the respective guide means fixed to the wheel radially on the axis.
14. 14. - A unit according to any of the preceding claims, characterized in that, in the rise station, the travel speed of the grip members is greater than the speed at which the opening devices are fed to the station. rise.
15. 15. - A unit according to any of the preceding claims, characterized in that the axis of the wheel is horizontal.
16. 16. - A unit according to any of the preceding claims, characterized in that the wheel operates continuously.