The present invention relates an apparatus for preparing wrapper elements or wrappers, for use preferably in a machine for wrapping a pasty, liquid or semi-liquid food product, and in particular, processed cheese.
Prior art machines for wrapping processed cheese portions use a flat sheet of material, normally aluminium foil, which is folded into a shell-like shape to form the lower body of the wrapper which receives the processed cheese product and the top of which is then closed by a cover strip, also made of aluminium foil and appropriately attached to the wrapper body.
In prior art machines for preparing the sheets so that each is ready to be folded to form the shell-like body of the wrapper, a web of aluminium foil is unwound from a roll and fed with stop-start motion. A cutting unit equipped with a blade having the shape of the wrapper to be made, cuts the individual wrapper sheets from the web. During one of the web stops, a single operation of the cutting unit creates a single wrapping sheet that will subsequently form the wrapper.
As the wrapping sheet moves forward with stop-start motion, a tear strip and a label are applied to opposite faces of it. In practice, the device that cuts the tear strip from a corresponding reel of material places the tear strip directly on the wrapping sheet during one of steps of the stop-start feed motion in which the wrapping sheet is stopped. Similarly, the device that applies the label to the other side of the wrapping sheet places the label directly on the wrapping sheet during a corresponding stopping step as the sheet moves forward. Feeding the sheet of aluminium foil with stop-start motion in this way, however, results in low working speed.
From a different viewpoint, another disadvantage of prior art machines is created by the complex procedures required at every changeover to synchronise the feed means of all the wrapper elements. Thus, when the length of the aluminium foil sheet, label and tear strip is changed, all the working parts used to transfer the foil sheets, labels and tear strips from the feed belt to the area where the foil sheets are folded to form the wrapper shells must be accurately re-adjusted.
Moreover, it must be stressed that the prior art machines of the type described above, in addition to the means for arranging the wrapper sheets, may comprise devices for arranging labels and tear strips, or they may comprise devices for arranging only labels or only tear strips or they may comprise neither of these devices, in which case each wrapper consists of a sheet without either label or tear strip.
The field therefore feels the need for a machine that can be easily set up according to the different configurations required by users of the machine.
An apparatus for preparing wrapper elements or wrappers, in a machine for wrapping a pasty, liquid or semi-liquid food product, and in particular, processed cheese, comprising means for arranging the wrapper elements, or parts thereof, at least including means for dispensing the wrapper sheets; the apparatus being characterised in that it further comprises wrapper element feeding means between the arranging means and the transport means downstream.
Thus, separating the operation of the dispensing means upstream from that of the wrapper forming means downstream, thanks to suitable intermediate feeding means, creates an extremely flexible machine structure that can easily be adapted to different user requirements.
The invention also contemplates the provision of an apparatus comprising means for synchronising the wrappers or wrapper elements which is located upstream of the forming or wrapping zone of the machine.
This eliminates the need to use more complex systems for adjusting the positions of the wrapper elements of the machine, and hence the need to plan down time for these adjustment operations to be performed.
The other claims relate to other advantageous aspects of the invention.
The technical characteristics and advantageous aspects of the invention are apparent from the detailed description which follows, with reference to the accompanying drawings, which illustrate a preferred embodiment of the invention provided merely by way of example without restricting the scope of the inventive concept, and in which:
The apparatus according to the invention is designed in particular for assembling a foldable sheet 12 made of suitable material, for example, aluminium foil, a linearly extending element or strip 14 which is used for tearing the wrapper open and which is laid on one face of the sheet 12, and a label 16, which is applied to the other face of the sheet 12, opposite the face to which the tear strip 14 is applied. The sheet and, if necessary, the tear strip, are then transferred to a forming station where they are folded into a shell-like shape to form a wrapper body suitable for receiving, at the following wrapping machine stations, a portion of pasty product which is then covered over and packaged in appropriate cartons together with other portions of the product.
This embodiment of the apparatus thus comprises means 18 for dispensing wrapper sheets 12, said means consisting of a first and a second conveyor belt 18 whose surface 20 supports the sheets 12 thanks to its permeable structure or suitable holes connected to suction means for creating a negative pressure, or pressure below atmospheric pressure, in such a way as to hold the sheets 12 to it by suction.
As illustrated in
The apparatus further comprises means 22 for dispensing the tear strips 14. The means for dispensing the tear strips 14 are embodied in first and second conveyor belts 22, 22 whose surface 24 supports the tear strips 14 thanks to its permeable structure or suitable holes connected to means for creating a negative pressure, or pressure below atmospheric pressure, in such a way as to hold the strips 14 to it by suction.
The first and second conveyor belts 22, 22 are designed to feed a respective row of tear strips 14, 14. As shown, each conveyor belt 22 is trained around respective end rollers 23a, 23b to define a front section 22', which supports and feeds the sheets 12, and a return section 22".
The apparatus also includes means for dispensing the labels 16, said means comprising a conveyor belt 26 whose surface 28 supports the labels 16 thanks to its permeable structure or suitable holes connected to means for creating a negative pressure, or pressure below atmospheric pressure, in such a way as to hold the labels 16 to it by suction. This conveyor belt 26 is wide enough to feed two parallel rows of labels 16, 16.
As shown, the label dispensing belt 26 presents a first section 26' for receiving and feeding the labels 16 towards feeding and assembling means 30, and a return section 26"'. As illustrated, the conveyor belt 26 is trained around respective end rollers 27a, 27b to define a section for receiving the labels 16 and a section for feeding and transferring them. Advantageously, the wrapper element feed means 30 are designed to sequentially receive and feed the tear strips 14 and the flat wrapper sheets 12 from the tear strip dispensing means 22 and the sheet dispensing means 26, in such a way that the elements remain centred, while following a circumferential path, relative to a defined centre line C of the receiving seat 32.
Further, as illustrated, the sheet dispensing means 18 present a respective end 18a extending in the proximity of the feed and assembling means 30 and an end 18b for receiving the sheets 12.
As illustrated in
For centring the sheets corresponding to each wrapper size in this way, it is sufficient to act on the dispensing means either by adjusting them or by providing them with suitable means for retaining and dragging the sheets on the conveyor 20, releasing them at a suitable point, in such manner as to increase the distance "d" between the sheets for smaller size wrappers. As illustrated, the feed means are preferably revolving means, embodied as a revolving wheel 30, having a surface 32 that supports the tear strips 14 and the sheets 12 thanks to its permeable structure or suitable holes connected to means for creating a negative pressure, or pressure below atmospheric pressure, in such a way as to hold the sheets 12 to it by suction.
The means 22 for dispensing the tear strips 14 also present a respective end 22a extending in the proximity of the feed and assembling means 30 at a receiving point which, in the direction of motion of the assembling means 30, is located upstream of the point where the sheets 12 are dispensed. Thus, each sheet 12 is placed on the assembling means 30 on top of the corresponding tear strip 14.
Similarly, the means 26 for dispensing the labels 16 present a respective end 26a extending in the proximity of the feed means 30 at a point downstream of the point where the sheets 12 are received.
Advantageously, the retaining surface 32 of the feed means 30 moves continuously at a predetermined tangential speed V0. In practice, the wheel 30 revolves at a constant angular speed such that the upper surface of each tear strip moves at a speed equal to V0.
Also the means 22 for dispensing the tear strips 14, the means 18 for dispensing the sheets 12 and the means 26 for dispensing the labels 16 move at a predetermined speed corresponding to the speed V0 of the feed and assembling means 30 so that the tear strips 14, the sheets 12 and the labels 16, respectively, reach the point where they are transferred to the feed and assembling means 30 in synchronised fashion as the respective sheets 12, tear strips 14 and labels 16 are passing by. At the moment of transfer, the suction which is holding the sheets 12, tear strips 14 and labels 16 against the respective retaining surfaces of the corresponding dispensing means is switched off.
As mentioned above, when changing over to a different wrapper size, the longitudinal spacing between successive tear strips 12, 12 on the dispensing means 18 must be changed accordingly. For changing the spacing, suitable means are provided, upstream of the sheet dispensing means 18, which suitably space the sheets so they are dispensed over the tear strips 18, 18 in such a way that they are centred on the receiving zone of the feed and assembling means 30, described in more detail below. The dispensing points where the feed means 30 receive the tear strips 14 and the sheets 12 are spaced in such a way that each sheet 12 is associated with a corresponding tear strip 14.
The dispensing point of the labels 16 is located, relative to the direction of motion of the feed and assembling means 30, downstream of the dispensing point of the sheets 12 at a distance such that each label 16 is associated with the corresponding sheet 12.
Each label 16 is placed over the corresponding sheet 12, which is already on a tear strip 14, coming to rest and being fixed to the face opposite the face that is in contact with the retaining surface 32 of the assembling means 30 and that is on top of the corresponding tear strip 14.
The invention also contemplates the provision of means 34 for transferring the assembled wrappers 17 to a unit 35 for forming or folding the wrappers.
These transfer means 34 receive the wrappers which have been assembled in the assembling means and feed them at a predetermined speed V0 equal to the speed at which they are fed by the wrapper forming or folding unit 33.
As illustrated, the means for transferring the assembled wrappers comprise at least one conveyor belt 34 whose lower surface 36 retains the assembled wrappers 17 thanks to its permeable structure or suitable holes connected to means for creating a negative pressure, or pressure below atmospheric pressure, in such a way that the assembled wrappers 17 are held to the retaining surface 36 by suction. As illustrated, the means 34 for transferring the assembled wrappers 17 are designed to feed the assembled wrappers 17 in a first and a second parallel rows.
The assembled wrapper transfer means 34 have a section 34' that receives and feeds the assembled wrappers 17 to the forming unit 33 to which it transfers each assembled wrapper 17 - from above - by switching off the retaining suction when the wrapper 17 reaches the forming unit 33 and the latter is ready to receive it.
The conveyor belt 34 is trained around respective end rollers 35a, 35b to define the section 34' for receiving and feeding the labels 16, and a return section 34".
Means which are not illustrated in the accompanying drawings are provided for adjusting the predetermined speed V0 of the assembling means 30 and of the means 18, 22, 26 for dispensing the wrapper elements. The predetermined tangential feed speed V0 of the assembling means is normally constant and equal to the feed speed of the unit 33 for folding the wrappers 33.
Further, for enabling the passage of the assembled wrappers 17 from the assembling means 30 to the transfer means 34, means 26" are provided.
The means for passing the assembled wrappers 17 are advantageously defined by a section 26" of the label 16 dispensing conveyor belt 26 downstream of the section 26' that receives and feeds the labels 16 to the assembling means 30.
As illustrated, the section 26" for passing the assembled wrappers 17 is trained around the roller 27b and a third roller 27c so as to form a conveyor belt that follows a triangular path. The section 26" for passing the assembled wrappers 17 receives the latter, from above, from the feed and assembling wheel 30 at a point substantially coinciding with the point at which the labels 16 pass.
In practice, the labels 16 are pressed and glued to the wrapper sheets 12. Immediately after this, the retaining suction on the wheel 30 is switched off and the assembled wrappers 17 are passed to the section 26" of the conveyor belt 26, which holds the assembled wrappers 17 to its upper retaining surface by suction and then passes them on to the transfer means 34 by switching off the suction.
The means 38 for cutting the tear strips 14 are advantageously positioned between the means 22 for dispensing the tear strips and the means 34 for transferring the assembled wrappers 17, thus reducing the overall size of the apparatus.
The cutting means consist, for each conveyor belt 22, of a suitably shaped blade (not illustrated in the accompanying drawings) driven towards the corresponding belt 22 in such manner as to cut the tear strip 14 and then away from the belt 22 to enable the latter to continue moving forward. The tear strip dispensing means 22 are driven at a speed such that the tear strips move at the same speed as the assembling means 30 and can be transferred to the assembling means 30, drive being intermittent so that the belt stops when the tear strips 14 are received from the cutting means 38.
Once the tear strips 14 have been cut, the conveyor belt 22 is accelerated to rapidly reach the speed at which the tear strips 14 are delivered to the assembling wheel 30. After delivering the tear strips to the wheel 30, the conveyor belt 22 is decelerated and rapidly stopped to enable other tear strips to be cut.
In the event of a wrapper size changeover, the tear strip cutting means are shifted lengthways along the corresponding belt 22 so as to adjust the longitudinal spacing between successive tear strip 14, 14.
The apparatus according to the invention may comprise suitable means for cutting the sheets 12 from a web of material for wrapper sheets 12. These means are not illustrated in the accompanying drawings and may have the form defined in Italian patent application No.
Means 40 are also provided for sealing the tear strips 14 to respective sheets 12. Advantageously, the means for sealing the tear strips 14 to respective sheets 12 take the form of a revolving heating roller 40 that is kept in contact with the surface of the feed and assembling means 30 that retains the tear strips 14 and the sheets 12 in such manner as to heat the sheets 12 placed over the respective tear strips 14. In this manner, continuous sealing of the tear strips 14 to the sheets 12 is achieved.
For sealing the tear strips, the sealing means 40 are designed to contact each sheet 12 at a point which, in the direction of motion of the tear strip 14 assembling means 30, is located downstream of the points where the tear strips 14 and the sheets 12 are dispensed. The provision of suitable means for feeding and assembling the wrapper elements, which receive sequentially the various preformed elements of the wrapper and whose feed motion is continuous or substantially continuous, makes it possible to achieve machine operating speeds that are on average higher than the speeds attained by prior art feed devices with stop/start motion. Machine productivity, in terms of number of wrappers made per unit time is appreciably greater than that of prior art feed devices with stop/start motion.
The apparatus according to the invention further comprises means for applying glue to the labels 16. The glue application means comprise two elements 42, 42 for applying glue to corresponding labels 16, 16. These elements are longitudinally spaced in the label feed direction, and the speeds at which the labels 16 are fed by the label 16 dispensing means and at which the application elements rotate are such that two longitudinally successive labels are fed to each glue application element 42.
As illustrated, these means comprise a pair of glue application devices 41, 41 designed to apply spots of glue to respective rows of labels 16, 16. The glue application means 42 apply three spots of glue to each label. In the present embodiment, the label is triangular in shape and is designed to be glued to the bottom of a processed cheese wrapper which, when completed, has the shape of a solid with a substantially triangular base.
As shown in particular in
As illustrated, the glue dispensing means in this particular embodiment are glue emitting nozzles 44', 49" connected by respective conduits 45 to a glue tank 47.
More specifically, each glue application element has a single nozzle 44' at the front and a pair of nozzles 44" at the back - only one of which is shown in Figure 20 - each of which puts a spot of glue on the blank face of the label 16 to be applied to wrapper sheet.
The means for driving the glue dispensing means comprise a plate 46 for mounting the glue dispensing means 44', 44". The drive means move the plate 46 along a closed path having one section parallel to the label 16 feed belt. The plate is carried by belts 48 carried on a first toothed wheel 50 and a second toothed wheel 52, longitudinally spaced from each other and equidistant from the label 16 feed belt 26.
Two pairs of these wheels 50, 52 drive respective belts 48 along a forward section and return section, enabling the mounting plate 46 to be kept parallel to the label 16 dispensing means. The first and second elements 42, 42 are carried by the same mounting plate 46 that moves along a closed path.
The glue application elements 42, 42 are longitudinally spaced in the label feed direction, and the speeds at which the labels 16 are fed by the label 16 dispensing means and at which the application elements 42, 42 rotate are such that two longitudinally successive labels are fed to each glue application element 42.
This glue application system has a simple structure and low cost. This glue application system is also easy to inspect. The apparatus according to the invention also comprises means for transferring the labels 16 to the means for dispensing the labels 16.
These transfer means comprise means for housing a plurality of labels 16 which, as can be seen in
As illustrated, the label 16 housing means advantageously comprise a plurality of pairs of tubes 54, longitudinally spaced in the direction, in which the labels 16 are fed by the dispensing means 26. Each pair of tubes is designed to feed corresponding labels 16.
It is thus possible either to feed different types of labels for different types of cheese or other pasty product to be wrapped or to create a larger, longer-lasting supply of labels in the label reservoir.
The labels 16 are stacked inside the tubes 54 which have an open lower end 54a designed to feed the labels 16 out one at a time. Means 56 are provided for picking up the labels 16 from the respective pair of label housing tubes and transferring them to the means 26 that dispense the labels 16.
More specifically, these label pickup and transfer means constitute means, as described in more detail below, for transferring the labels to continuously moving means.
As can be seen also with reference to
The disk 60 mounts the means 58 for gripping the labels 16. As illustrated in
As illustrated, the portion 58c projects outwards in a direction transversal to the supporting portion 58b. Further, the L-shaped body 58 for gripping and supporting the labels is pivoted at 58a to the drive disk or means 60.
Means 62 are provided for moving the label 16 gripping element 58 between an outside extended radial position and an inside retracted radial position.
The outside extended position of the gripping means 62 is created when the means 58 are moved to the label reservoir 54 and to the label feed belt 26 to define, respectively, a position of picking up and a position of transferring a label.
The drawings show only the position where the label is transferred to the conveyor belt 26.
During their movement from the label reservoir 54 to the conveyor belt 26, the label gripping means 58 are kept in the retracted position which enables the label to be held more securely. The label gripping means 58 are also kept in the retracted position during their movement from the conveyor belt 26 to the label reservoir 54 after the label has been released onto the belt 26.
The outside extended position of the means 58 when they reach the reservoir 54 enables them to pass the edge 54'a of the reservoir so that the retaining surface 59 is close to the lower edge 54'a of the reservoir 54 and the lowermost label in the reservoir 54 can be extracted by the suction through the label supporting surface 59.
Once the end surface 59 of the element 58 has been positioned between the walls of the label reservoir 54 causing the end to protrude from the reservoir 54 and enabling the next edge 54"a of the lower edge of the reservoir to be past, the label gripping element 58 is radially retracted. For transferring the label to the conveyor belt 26, the element 58 is moved outwards so as to impinge on the belt 26. The means for moving the gripping element between an extended position and a retracted position comprise a cam profile 62 that acts in conjunction with a corresponding portion 64 of an L-shaped drive lever 63, in this particular embodiment, a roller 64, pivoted at 64' to the L-shaped lever 63 at the end 63b of the latter. The drive lever 63 is pivoted to and supported by the transfer disk 60 at 63a at the bend in the L-shaped lever body 63 and has another portion 63c with a curved rack 65 on the end of it which is designed to mesh with the teeth 67' of a pinion 67 attached to the supporting portion 58b of the label pickup portion 58c, in such manner that rotation of the lever 63 caused by the cam 62 imparts rotational motion about the pin 58a on the element 58 and radial motion on the label pickup surface 59.
The connecting means created by the rack 65 and the pinion 67 define a gear ratio that can be appropriately chosen so that small radial movements of the cam follower roller 64 on the cam 62 cause a desired large radial movement of the label pickup surface 59. Thus, the overall dimensions of the device are advantageously limited.
Means are provided for moving the cam 62 between an outside extended radial position and an inside radial position.
The means for moving the cam 62 between an outside extended radial position and an inside transfer position take the form of a crank 66 connected by a link 68 to the base 62' which bears the cam 62 and which is coaxially housed in a circular opening made in the disk 60, thus creating a structure of limited width.
In practice, in a first working condition, where a label is extracted from the label reservoir, the disk 60 is stationary and the pickup element 58, with suction on, is positioned at the label 16 housing tube 54 and sucks the label 16 out of the tube.
Starting from this position, the crank 66 rotates and, through the arm 68, imparts rotation on the cam 62, whose profile forms a radial protrusion that causes the pickup element 58 to retract radially by rotating about the connecting pin 58a pivoted to the disk 60. At this point, the disk 60 turns by 180° dragging the pickup element 58 along with it, thus carrying the label 16 to the position shown in
When the label pickup element 58 reaches the conveyor belt 26 below it, and while the disk 60 continues to rotate, the cam 62 pushes the pickup element 58 outwards and imparts on the end surface 59, which is carrying the label, a speed corresponding to the speed of the conveyor belt 26, thus enabling a "running" transfer of the label, that is to say, enabling the label to be released by the pickup surface 59 onto the dispensing belt 26 while the belt 26 is in motion. The label is dropped by switching off the suction at the end surface 59 of the label pickup element 58.
Next, by an opposite movement to the pickup movement, the cam 62 is rotated in such a way as to cause the end surface 59 of the element 58 to retract, and the disk 60 turns by 180°, taking the pickup element 58, now without a label on it, back to the label reservoir 54.
During this step, the cam 62 remains in substantially the same position relative to the disk 60, that is to say, it rotates with the disk so that the label pickup element 58 remains in the retracted condition. At this point, the cam 62 rotates while the disk 60 remains stationary, thus enabling the pickup element to be inserted into the label reservoir tube 54 to extract another label 16.
The label arranging means described above place the labels at regular intervals, that is to say, with predetermined spacing, so that the distance between the ideal centres or reference points of the labels (corresponding to the spacing), which corresponds to the ideal centre distance or spacing of the wrapper sheets in the sheet dispensing area on the assembling means, is always the same, whatever the size of the wrappers. This means that the system can handle labels of different sizes, for different wrapper lengths, the labels always being in a centred position when they reach the area where they are dispensed to the assembling means 30.
The next set of drawings illustrate another embodiment of the apparatus for preparing wrapper elements or wrappers, for use preferably in a machine for wrapping a pasty, liquid or semi-liquid food product, and in particular, processed cheese.
This second embodiment of the apparatus according to the invention comprises means for arranging the wrapper elements, or parts thereof,, including means 122 for dispensing, in particular, tear strips, that is, elements used to tear the wrappers open, said means consisting of cutting means comprising first and second cutting elements 122, 122, which place a first and a second part of the tear strip simultaneously on two consecutive seats 132 of the wrapper feed means, as described in more detail below.
The cutting elements 122, 122 are positioned one after the other and are angularly spaced in the feed direction A.
The cutting means take the form of a blade 138 designed to cut the tear strip from a tape 115 of suitable material.
Means 139 are also provided for driving the cutting means 138, in alternating fashion, between a retracted position where the tear strip material is fed to the cutting means 138, and a forward position where the tear strip is cut and transferred to the feed means of this embodiment.
More specifically, the cutter blade drive means comprise a stem 139' which bears the cutting blade 138 on the end of it.
The tape of tear strip material is unwound from a reel 115'.
In this embodiment, the cutting elements are of the same type and are used to cut identical tear strips. In simple terms, the cutting elements are suitably oriented relative to the respective base, that is to say, in a direction substantially opposite the direction in which the wrapper elements are fed, in such manner that the tear strips placed on the seats 132 are arranged according to an X or Y-shaped configuration.
Downstream of these tear strip dispensing means, there are means for dispensing wrapper sheets, said means comprising a revolving roller 118, with suction holes or grooves 118', which feeds the wrapper sheets with continuous or substantially continuous motion.
More specifically, the dispensing means or roller 118 preferably moves at a constant or substantially constant angular speed.
These wrapper sheet dispensing means make it possible to attain high operating speeds.
The web 112' of wrapper material, normally aluminium foil, slides over the roller. The individual wrapper sheets, after being laterally shaped are cut transversely from the web.
Downstream of the sheet dispensing means, there are sealing means 140 designed to seal the wrapper sheets to the tear strips and consisting of a plate 140 with a fixed heated contact surface 141.
Alternatively, a sealing plate that remains in contact with the wrapper elements to be sealed while moving along with them for a certain length in the direction of feed might also be contemplated.
Downstream of the sealing means, there are means for dispensing labels which comprise means for feeding the labels consisting of a conveyor belt 126 driven continuously or substantially continuously at a constant speed so that high operating speeds can be attained.
As illustrated, the conveyor belt 126 has an inclined section 126' that makes an angle B with the vertical. This limits the overall dimensions of the apparatus and creates means for assembling the label to the wrapper sheet at an end area 126a of the inclined section of the label feed belt.
Thus, the label is received on a section 126b located upstream of the assembly point and being provided, at an area 126c following the label positioning area between the point where the label is received and the assembling point where it is applied, with adhesive used for gluing the label to the bottom of the wrapper sheet. The label is picked up from a reservoir 154 and placed on the conveyor belt 126 at predetermined intervals by suitable means such as those of the embodiment described above.
This creates a simple structure and, more specifically, makes it possible to reduce the length of the wrapping machine.
Further, the label feed means also constitute means for transferring the wrapper element to the means 134 that convey it to the wrapper forming, filling and sealing means of the processed cheese wrapping machine through a short, upper horizontal section 126d located downstream of the inclined section where the wrapper element is received.
According to another aspect of it, between the means for preparing the wrappers and the downstream conveyor means 134, the present invention contemplates the provision of means 130 for feeding the wrapper element and comprising a plurality of receiving seats 132 located at intervals of predetermined length P.
Thanks to these intermediate feed means, the wrapper elements can be positioned at predetermined intervals from each other upstream of the wrapper forming area, whatever the size of the wrappers. Thus, when changing over to a new size in a machine equipped with the apparatus according to the invention, it is not necessary to re-adjust all the wrapping parts, as is the case with prior art machines where practically all the working parts must be adjusted and re-timed.
This means that, compared to prior art machines, changeover down time is eliminated. According to yet another aspect, the apparatus according to the invention constitute feed means for synchronising the wrappers or wrapper elements upstream of the forming or wrapping zone of the machine.
Advantageously, the working motion of the feed means 130 is continuous or substantially continuous, thus making it possible to attain higher working speeds than those possible in prior art.
The feed means according to the invention comprise means 132 for supporting the wrapper element and/or a part of it and consisting of a plate with a surface 132a that supports the wrapper or wrapper element and that is equipped with suitable retaining means consisting of suction means designed to hold the wrappers or wrapper elements to the supporting surface 132a.
Advantageously, the means 132 for supporting the wrappers or wrapper elements are moved by feed means 133 consisting of a revolving wheel 133 that moves continuously or substantially continuously at a constant speed. This wheel configuration minimises the space occupied by the apparatus in the wrapping machine.
Means are also advantageously provided for moving the supporting means relative to the means 138, 118, 140, 126 for arranging the wrapper or wrapper element, in such manner as to perform a corresponding operation on the wrapper or wrapper element.
The means for moving the supporting means move, in particular relative to the feed means 133, between a retracted position, illustrated, for example in
In practice, in a first advantageous working condition, the means for moving the means for supporting the wrappers or wrapper elements are designed to keep the supporting means in a condition such that they are stationary relative to the working means "outside" the feed means, whilst the feed means 133 themselves impart on the supporting means 132 a continuous motion at constant angular speed. This means that the required operation can be performed in the optimum manner without interrupting the feed motion, thus making it possible to attain high working speeds.
More specifically, as illustrated in
The means for moving the means for supporting the wrappers or wrapper elements are designed to rotate the supporting means, as illustrated schematically in
The means for moving the means for supporting the wrappers or wrapper elements are designed to keep the supporting means 132, as illustrated schematically in
According to yet another aspect, the means for moving the means for supporting the wrappers or wrapper elements are designed to keep the supporting means 132 in a condition such that they are parallel to a corresponding surface of the label feed means 126, the surface of the supporting plate of the supporting means following the same linear movement as the label feed belt. All this is carried out while the feed means 133 impart on the supporting means 132 a continuous motion at constant angular speed.
During this step of transferring the assembled wrappers, the suction that holds the wrappers to the supporting means is switched off so that the wrapper sheets can be released and transferred to the conveyor means that carry them downstream towards the forming area where the wrapper is completed.
As illustrated, the means for moving the supporting means, comprise a first supporting arm 135 and a second supporting arm 137 which are linked in articulated fashion at the ends 135a, 137a to the means 132 for supporting the wrapper element and at the other ends 135b, 137a to the feed means 133 in such a way that the supporting means 132 move in parallel with the feed means so that they can receive a wrapper or wrapper element from the feed means in a suitable manner.
The invention also contemplates the provision of means, which are not illustrated in the accompanying drawings, for rotationally driving the arms 135, 137 in such a way as to keep the supporting means near the feed means for a sufficient length of time to receive the wrapper element.
The means for linking the feed means comprise means for driving the articulation pins 135c, 137c of the supporting arms 135, 137, said drive means being defined by a first linkage consisting of a lever 139 and a second linkage consisting of a circular plate 141 rotatably retained within a respective circular seat 141 in the feed means 133.
At their ends 139a, 141a, these drive means support the articulation pin of the respective supporting arm and, at their other ends 139b, 141b, are joined to a shared articulation pin 143 fixed to the feed means 133.
Means which are not illustrated in the accompanying drawings are provided for driving the first and second linkages or drive means between a position in which the arms are in the conveying condition and a position in which the arms are in the pickup condition.
In practice, driving both linkages in opposite angular directions adjusts the radial position of the wrapper or wrapper element relative to the arranging element, driving one or both linkages in the same angular direction through a suitable angle suitably variable over time causes the supporting plate to rotate, and appropriately combining the movements of the linkages and of the wrapper element holding arms creates the desired operations described above.
Thus, the structure of the drive means is such that the wrapper element holding means can perform all the movements required for each operation.
As illustrated, the feed means according to the invention constitute advantageous means for assembling and synchronising the wrapper elements with each other.
Thus, the machine can be easily adapted to different types of wrappers: for example, wrappers with or without tear strip, without requiring significant changes to machine structure.
In the apparatus according to the invention, the provision of suitable means for feeding the wrapper, which sequentially receive the wrapper sheets and place them in suitably spaced seats, and where the motion of the feed means is continuous or substantially continuous, makes it possible to makes it possible to achieve machine operating speeds that are on average greater than the speeds attained by prior art feed devices with stop/start motion. Machine productivity, in terms of number of wrappers made per unit time is appreciably greater than that of prior art feed devices with stop/start motion.
In the apparatus according to the invention, the provision of suitable feeding and assembling means having seats for sequentially receiving the wrapper elements, which are suitably spaced at predetermined intervals and where the wrapper elements are centrally positioned permits the creation of wrappers which, whatever their size, are always in the correct feed and working position for the machine units downstream but without requiring the use of complex systems for adjusting the relative positions of the machine units.
The other claims define other advantageous aspects of the invention.
It will be understood that the invention can be adapted and varied in several ways without thereby departing from the scope of the inventive concept. Moreover, all the details of the invention may be substituted by technically equivalent elements.
This list of references cited by the applicant is for the reader's convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.