FR2471851A1 - Appts. for automatic manipulation of tubular packaging film - with cam mechanisms interchangeable to suit different sleeve or pack formats - Google Patents

Abstract

Appts. for fitting a sleeve of flexible thermoplastic film around some rigid object is provided with pairs of suction grips which can contact opposite faces of a flattened sleeve and then separate first parallel and subsequently normal to the plane of the film to open out the sleeve sufficiently to accept insertion of two or more rigid formers. The rigid formers can then develop to extend the film sufficiently to accommodate the item to be enclosed by the sleeve. The sleeve may then be fitted while again supported by the external suckers, e.g. by a longitudinal shift and/or radial contraction due to thermal contraction, elasticity, etc. The vertical and lateral motions of the supports for the suction grips and for the rigid formers are individually controlled by cam templates acting in radial or axial planes. By changing the size and shape of the suction supports, the rigid formers and the cam mechanisms, the appts. can be adapted to suit a variety of sleeve sizes and package forms. The initial longitudinal separation of the opposing sets of suction grips helps to part any internal blocking of the flattened film.

Description

The present invention relates to the field of making sheath sections or sleeves in thehmoplastic material, for example retractable or stretchable, and intended to be placed around containers or other objects. It relates more particularly to a new process, as well as the appropriate apparatus, for opening and transferring sleeves around containers, from a continuous strip of thermoplastic flat sheath, previously cut out into sections of determined length.

 It is now well known to provide receptacles such as bottles, aerosol cans, flasks, cans and the like, made of various materials, with a sleeve. or protective sleeve in thermoplastic material. This sleeve is arranged around the container to produce receptacles provided with sheaths, generally printed, in transparent opaque thermoplastic material or in porous or cellular plastic material.

Many operating steps are necessary to pass from the sheath or the thin sheet of plastic gas (for example polyvinyl chloride), made heat-shrinkable, to the receptacle provided with its decorated covering. These stages must be automated in order to reach a suitable profitability. According to a technique commonly used until now, the plastic film is made from a continuous sheath or sheath and then sections of sheath are cut to the appropriate dimensions and the sleeves obtained, stacked horizontally or vertically in a store, are used to feed a machine allowing to individually extract the sleeves then to open them the desired conformation and to deposit them around the receptacles keys to revetrr which circulate on a conveyor, the dressing being able metra then subjected to a heat shrink (see for example French patent N 76005033 and American patent N04. # I8.9i6)
This process is certainly satisfactory but the production cadets are relatively limited due to the complexity of the operations of opening the sleeves.

According to another technique, aimed at production and fitting sleeves at high speed, an automatic machine is used which directly uses the continuous flat sheath of plastic film and not stacks of sheath sections as raw material, and which performs the series operations of O shaping, cutting, guiding and fitting the gracie sleeve to a series of stepped means arranged around a hollow mandrel along a vertical line which overhangs the series of
receptacles to be coated traveling on a conveyor (see for example European patent application N078.400045.7 and American patent NO 4179863). Such a machine gives excellent results and allows very high rates of fitting sleeves, of the order from 150 to 200 per minute, around containers to decorate. It is however suitable for receptacles of a given shape and capacity and is therefore not very flexible.

 The object of the invention is to develop an apparatus suitable for making and fitting sleeves on receptacles of various conformations. It also aims both to simplify and to make even more reliable the operations of opening a section of sheath then laying around the receptacles.

To achieve such a result, the invention provides a process in which one also starts from a continuous flat sheath of thermoplastic film which is cut into sections or sleeves but where the originality lies in particular in the opening phases. of the sleeve before it is placed on the container.

According to its general definition, the method implements the succession of the following steps
pressing at least one suction cup connected to the vacuum on each of the two opposite faces of the flat sleeve, while the latter is maintained in a vertical position; during this support, translation of at least one of the suction cups along a single face of the sleeve so as to cause an offset of the two series of suction cups surrounding the sleeve relative to their line of primitive position; vacuum connection of the suction cups and, while the sleeve is thus kept ajar, positioning of this sleeve from bottom to top around a shaping device constituted by at least two plates capable of moving one relative to the 'other and joined at this operational stage; opening of the shaping plates in extension; release of the suction cups and slight tightening of said plates; recovery of the sleeve by the vacuum suction cups and descent of the sleeve by the latter around the container to be coated, the vacuum is then cut and the suction cups separated from each other.

The originality of the abovementioned process therefore essentially rests on two characteristics, namely: the displacement of the suction cup (s) bearing on one face of the vertical sleeve while the suction cup (s) bearing on the other face remain fixed and, on the other hand, the particular structure of the shaping device constituted not by a unitary mandrel or articulated clamps as is known per se, but by separate elements> possibly shaped, capable of moving apart and approaching each other in the primary purpose of adapting the shape of the sleeve to that of the container to be coated.

 In accordance with its first abovementioned characteristic, the series of suction cups (for example two) has aces on each side of the sleeve are supported by articulated arms translatable relative to one another. During this translation, carried out while the suction cups pressing on each of the two faces of the sleeve, there is detachment and a very slight opening of the walls of the ther moplastiqua sleeve. At the time of the vacuum suction, the brassupports stecartent and the opening of the sleeve is enlarged which allows, in the next phase of the process, to introduce the sleeve into the shaper.

 Alternatively, the vacuum connection of the suction cups can occur before the translation phase of at least one of the suction cups. Furthermore, according to another embodiment, the detachment of the walls of the sleeve can also be obtained by displacements of the two series of suction cups on each side of the mandrels, these displacements being carried out in opposite directions to one another.

 According to the second aforementioned characteristic, the shaping device comprises at least two plates which, when the sleeve is threaded, are tightened one on the other and which are then put in extension to give the sleeve the desired final conformation. In practice, several variations of variants can be implemented for this conformator. For example, two curved plates can be used in an arc of a circle and the cavities of which face each other, such an embodiment being suitable for ovoid-shaped sleeves. Alternatively, four separate plates, all slightly curved, or four plates may be used. rectilinear intended to substantially form a rectangle In accordance with another embodiment, two of these four plates, in particular those of shorter length, can have the configuration of two articulated segments 9 which can be folded inside the two other plates of greater length and which are face each other. Such elements will be described in more detail in the embodiments illustrated by the drawings.

 The implementation of the two main characteristics of the process according to the invention can be done on any machine provided with means, known per se, capable of coordinating the actions of the suction cup support arms and the opening-closing movements of the plates of the conformator so as to obtain: the start of opening of the sleeve, its threading around the conformator, the extension of the latter then the removal of the sleeve around the container.

 However, as a preferred embodiment, although not limiting, an automatic machine has been developed specially adapted to the implementation of the abovementioned process and which constitutes one of the objects of the present invention.

Such a machine according to the invention is characterized in that it comprises, in addition to a supply known per se in a sheath then a cutting of the latter into sleeves of appropriate length, an assembly constituted by
a) a bucket, arranged on a rotating disc, for receiving vertically each flat sleeve;
b) a rotary work table (or distributor) served by said disc and comprising several superimposed circular platforms which support
a gripping device with suction cups supplied intermittently by means of vacuum suction
a former consisting of at least two movable plates
a set of three cams intended respectively to control the opening and closing of the shaper (upper cam), the programmed phases of spacing and reassembly of the suction cups around the sleeve (intermediate cam), the raising and lowering of the suction device . (lower cam) said table # étanf mounted on a fixed or mobile chassis equipped with a motor and a vacuum pump.

The method will be better understood by the detailed description of an illustrative embodiment, applied to a machine with the above general characteristics and the details of structure and operation of which will be highlighted. For this purpose, reference is made to the accompanying drawing plates which schematically represent
Figure 1: the succession, in simplified form, of the various operating phases a) to h) of the method according to the invention;
Figure 2 in Figure 7: several alternative embodiments of a shaper usable according to the method;
Figure 8: a simplified representation, in perspective, of an automatic machine for implementing the method
Figures 9 to 13: very schematic views illustrating, on the essential organs of the machine according to Figure 8, the main phases of the process; and
Figures 14 to 16: views in projection of the general configuration of the three cams with which the machine of Figure 8 is provided.

 We will first refer to the two plates numbered 1/5 and 2/5 to visualize the implementation of a general process, according to the invention, of opening a section of sheath or sleeve (for example in vertical position) then threading around a shaping device and removing the sleeve around a receptacle.

 According to phase a) (fig. 1), the two faces of the sleeve Q are held tight 1 rune against the other by two series of suction cups 2 and 3 by pressing on said faces. Of course, to simplify the sin, the suction cup supports and the vacuum connection pipes of the latter have not been shown.

 Then, as indicated in position b), a relative displacement of the suction cups 2 and 3 is carried out, still resting on the faces of the sleeve 1. Such an offset, under friction, causes a slight opening of the sleeve 1, which is then accentuated by connection of suction cups to vacuum suction (phase c). According to operation d) #the sleeve is then engaged on the conformator, constituted here by two plates 4 and 5 in an arc of a circle which, at this stage are closed against one another. It is then that the opening of the former is caused by progressive separation of the plates 4 and 5 according to the figure e) then f). When these plates are at maximum extension (position f), the two folds of the sleeve I using heating cylinders 6 and 7 (or other equivalent means) which are available; here on the unsupported parts9 ctest- -dire an free extension, of the sleeve 1. After a possible phase g) of realignment of the suction cups, of the form and the sleeve, the plates of the conformator are slightly loosened and the sleeve 1 is lowered accompanied by the suction cups 2 and 3 around the container 8 to be coated (phase h) .After cutting off the vida, the coughs are then moved aside then return to their position a) taking over a new sleeve to start the cycle again operative susdéw cri t From its dimensionS the sleeved container 8 is ejected for eBtreesubjected after a shrinking operation according to the known technique.

 While the conformator can be constituted, as indicated above, by the two curved plates 4 and 5 able to be cut one against the other (fig. 2 b) then separated (fig. 2 c) by example using a device 9 of the wedge type or the like, other embodiments are suitable for the process. For example, the shaping device can comprise four distinct elements of linear conformation 10, 11, 12, 13 as shown in FIGS. 6 and 7 or of concave structure 14, 15-, 16, 17 as illustrated in FIGS. 4 and 5. These elements can be coordinated with each other so as to provide one or two fold-back positions. For example, as can be seen in FIG. 3 with the extension positions 3 a and fold-back 3 b, the curved plates 18 and 19 include each two articulated segments 20 and 21 arranged at the lower part of said plates. Thus, thanks to the new shaping design according to the invention, it becomes possible, by simple change of tooling, to install sleeves around containers of all shapes: ovoid, rectangular, square, cylindrical, frustoconical, etc.

 The main components of a fully automatic machine for carrying out the above-described process are illustrated # schematically in the perspective view of FIG. 8, purposely stripped of the auxiliary control devices, vacuum pipes, etc.

etc to facilitate understanding.

Such a machine is served by a coil 22 of supply in a thermoplastic flat sheath and delivers # its output from the containers.
pients 23 provided with sleeves. It essentially includes: an app
reillage A supply in flat sheath and cutting of it in
sections of predetermined length or sleeves; a bucket system B
or baskets for receiving sleeves in vertical position and then dis
tribution of these to a rotary assembly C which constitutes the
"heart" proper of the machine, that is to say where s1 is performed
the succession of opening-shaping support operations
then place sleeves around the containers. Note that the device
for feeding containers to be sleeved and for collecting reci
pients coated with sleeves have not been shown in this figure 8.

Thermoplasti flat sheath supply device A
that is of a type known per se, such as for example that described in the
French Patent No. 77.23873. it includes a coil 22 of supplies
in neutral thermoplastic sheath, printed or decorated, cylinders3
24 sheath traction, a flexible interlocking system (not shown
intended to constitute a sheath reserve, advance cylinders under
tension 25 and 26 which bring the film into a cutting block 27 where the
sheath is cut into sections or sleeves 1 by a cutting system
with blades not forming part of the invention.

The sleeve receiving device B comprises a
tray or disc 28 on which distribution baskets are fixed
or buckets 29 provided with uprights intended to collect a sleeve in
vertical position, from the cut made in block 27. The disc
28 is rotatable and is used to distribute the sleeves on the work table
vail of machine C, as will be explained below In practice
each disc 28 can comprise several buckets 29, for example three,
who act as distributors for machine C.

Machine C, resting on a frame 30 with trays, com
carried several rotary circular platforms, here two numbered
31 and 32, which support respectively: a gripping system 33
a conformator 34; suction cup support arms 35, pivotable
and translatable in height; a unit of heating cylinders 6, 7
for unfolding; an entry system and an exit system (not
shown) for the containers 23 to be coated with sleeves.

The platforms 31 and 33 are integral with three
cams, namely: an upper cam 36 on which the head rests
holding device 33 of the shaper and which controls the ope
opening rations # not fitted, lowering-closing of the shaper 34 9
an intermediate cam 37, disposed under the working platform 32
and which controls the different programmed phases of the movements
as well as opening-closing of suction cup support arms 35 9 a
lower cam 38 corresponding to the raising and lowering of the arms
supports 35 during operations of threading the sleeve around the conform
mating then lowering and expulsion of the sleeve.

The frame 30 includes a vacuum pump 39 to which are connected flexible pipes (not shown) which terminate at the suction cups 2,3, as well as a motor 40 whose axis controls a toothed wheel (not visible) meshing with the central shaft 41 which drives the rotation of the platforms and the cams along the arrow 42 On this wheel are mounted sprockets for driving, for example by belt, various members such as t receptacle grip to be coated on a conveyor (elements not shown), container discharge finger 23 after dressing, disc tray 28 for supporting the buckets 29. The central shaft 41 drove the two trays at the same speed and on this shaft is mounted the head 43 for rotating and translating up and down of the suction cup support arms 35.

 Although, to simplify FIG. 8, we have represented only in a single copy the shaper 34 and its control head 33 as well as the suction arm-support system 35, it should be understood that the machine is normally equipped with several work stations including, for example, three conformers and three suction gripping devices, which work offset with the same supply 22 in flat sheath and with three buckets 29 with vertical sleeves on the rotary service disc 28.

 Although the successive phases of the method according to the invention have already been listed previously, we will return below to the main steps with the help of the illustration of Figures 9 to 16 which show the essential organs of the machine of Figure 8 .

 FIG. 9 illustrates the respective positions of the shaper 34 and of the suction-bearing support arms 35 just before the suction cups take up the sleeve 1. The latter has just been placed between the uprights of the trough 29 and is maintained in vertical position. Another sleeve 1, on the left, is waiting after being cut from the block 27. In this position, the two plates 4 and 5 of the shaper are closed.

 In the following phase, the suction cups 2 and 3 (for example two on each support arm 35) are placed on each side of the sleeve 1 and then moved by relative movement while exerting on said faces a friction, which causes the separation of these faces.

 if this has not already been done before, Puispbn connects the vacuum suction in the pipes 44 which causes the opening of the sleeve.

the following operation, illustrated in FIG. 10, corresponds to the engagement and ascent phase of the sleeve 1 around the plates 4,5 of the shaper, by vertical tranlation along the arrow 45 of the support arms 35 the suction cups 2, 3 still being supported on the faces of the sleeve.

 After extension of the plates 4; 5 of the former to the maximum spacing, the sleeve 1 passes between two heating cylinders 6,7 (see FIGS. 11 a and 11 b) arranged each at the level of the straight line which underlies the two arcs of a circle formed by the two curved plates 4,5 of the shaper.

After presentation of the object to be sleeved on the working platform 32, for example by means of an accompanying finger 46 (see fiv.13), the descent phase of the sleeve takes place on the container in question 8 , 23, which is illustrated in FIG. 12, the ven allas 2,3 accompany this descent of the sleeve to a controlled and predetermined height depending on whether the sleeve must cover part or all of the container
The #de is then cut and the suction cup support arms 35 are completely separated as can be seen in FIG. 13 which corresponds to the phase of evacuation of the sleeved container 8,23 on the
possibly path 47 leading / to a device for hot shrinking of the sleeves.

 After this ejection from the container and while the platforms continuing to rotate, the support arms 35 close again to find themselves in the first position for taking the change of a sleeve, illustrated in FIG. 9.

 FIGS. 14 to 16 show the complex and specially adapted conformation of the aforementioned three cams 36, 37 and 38, the functions of which have been defined. These cams allow the initiation and timing of each operation and the coordination of the various phases. By way of example, the correspondence between the various operations and the attachment points of the structures of these cams is indicated below.

On the upper cam 36 for controlling the operation of the conformator, there are the following phases, from left to right: support for the sleeve, the conformator being closed (item 48) then: at 49, gradual opening of the conformator; at 50, unfolding by the heating cylinders; at 51, realignment of the suction cup-shaper assembly; in 52, descent of the sleeve around the container then, in 53, the end of the operational cycle; the path 54 corresponds to the closure of the shaper for the next work cycle.

 Intermediate cam 37 (fiv.15) is used to control the movement of the suction cups. There are successively phases #: 55 for taking charge of the sleeve, 56 for tightening the suction cups on the sleeve and the displacement of these to cause the separation of the walls of the sleeve, 57 for the slight opening of the sleeve, 58 for the rise of the sleeve on the former ~ and the gradual opening of the latter, 59 for the unfolding operation, 60 for the descent of the sleeve on the object to be coated, 61 for the opening of the suction cups, the time death 62 corresponding to the return to cycle which begins in 55.

Finally, the lower cam 38 in FIG. 16 controls, let’s call it up, the vertical translation operations of the suction cup support arms 35. The support for the sleeve corresponds to reference 63 then we have successively: at 64, the start of opening of suction cups; in 65, the rise of the support arms (and therefore the sleeve) around the shaper; in 66 11 unfolding operation; in 67 the realignment of the suction cups; in 68 the descent of the support arms and suction cups on the object to be coated then in 69 the end of the operating cycle, the return to the next cycle taking place along line 70.

 A machine as described below is fully automatic with programming of phases and allows good opening rates and fitting sleeves around containers. In addition, it allows, by simple tooling changes (in particular of the shaping assembly), to cover a very wide range of shapes and dimensions of sleeves able to adapt to all types of containers. Of course, as indicated above, it constitutes only one nonlimiting embodiment of the method of the invention.

Claims (10)

R E V E N D I C A T I O N S  1. Method for opening and fitting sheath sections or sleeves in thermoplastic film around containers or various objects, from a continuous strip of flat sheath previously cut, characterized in that one puts in works the following sequence of steps: pressing at least one suction cup connected to the vacuum on each of the two opposite faces of the flat sleeve, while the latter is kept in the vertical position: during this pressing, translation from one to less of the suction cups along one side of the sleeve so as to cause a shift of the two sets of suction cups surrounding the sleeve relative to their line of original position; vacuum connection of the suction cups and, while the sleeve is thus kept ajar, positioning of this sleeve from bottom to top around a shaping device constituted by at least two plates capable of moving one relative to the 'other and joined at this operational stage; opening of the shaping plates in extension; release of the suction cups and slight tightening of said plates; recovery of the sleeve by the vacuum suction cups and descent of the sleeve by the latter around the container to be coated with the vacuum then being cut and the suction cups spaced from each other.  2. Method according to claim 1, characterized in that the connection to the vacuum of the suction cups can be carried out before said translation and in that the translation of the suction cups can be done on both sides of the sleeve by respective displacements of said suction cups in two directions opposite.  3. Method according to any one of claims 1 or 2, characterized in that during the extension of the plates of the shaper, # a hot unfolding of the sleeve is carried out. lower 38); said table being mounted on a fixed or mobile chassis (3û) equipped with a motor (40) and a vacuum pump (39). and lowering the suction cup device (cam around the sleeve (intermediate cam 37), the rise  suction cup spacing and reassembly of the shaper (upper cam 36), the phases order respectively :: opening and closing . a set of three cams (36, 37, 38) intended for moving plates . a conformator (34) consisting of at least two  empty  intermittently by suction through the  . a gripping device (35) with powered suction cups  - overlays that support  said disk and comprising several circular platforms  vertical to each flat sleeve; b) a rotary work table C (or distributor) served by  4 automatic machine for implementing the method according to any one of claims 1 to 3, characterized in that it comprises, in addition to a supply known per se in sheath then a cutting of the latter into sleeves of appropriate length, an assembly consisting of a) a bucket (29), disposed on a rotating disc (28), for receiving  5. Machine according to claim 4, characterized in that the disc (28), supporting the bucket or basket (29) for distributing the vertical unit sleeves, is controlled in rotation by a cross type system. Malta driven by the central axis (41) of the work table, which serves as a vacuum column for the vacuum gripper.  6. Machine according to claim 4, characterized in that the suction gripping device is constituted by two support arms (35) articulated, detectable with respect to each other and each provided with two vacuum pipes terminated by suction cups (2, 3), the relative movements of said arms and said suction cups being controlled independently of one another by the intermediate cam (37) and the lower cam (38).  7. Machina according to any one of claims 4 to 6 characterized in that the shaper (34) comprises four independent elements, linear or of curved shape, two of said elements being able to fold inside the other two during the closed position of the shaper, the opening and closing operations of the elements or plates being controlled, in coordination with the relative movements of the suction cup support arms, by said upper cam. 8. Machina according to any one of claims 4 to 7 characterized in that it further comprises, on one of the circular platforms, an assembly of the heating cylinder type (6, 7) intended for the unfolding of the sleeve.  9. Machine according to any one of claims 4 to 8 characterized in that it comprises, on said rotary disc (28), several buckets (29) and, on the work table, several assemblies: gripping devices (35 ) with suction cups and conformers (34), these buckets and assemblies being offset with respect to each other on their circular supports so as to carry out, in alternation of phases, at least three successive operations of opening sleeves and laying around containers to be coated.  10. Machine according to any one of claims 4 to 9, characterized in that alla is furthermore provided with a supply means (46) and a discharge means (47) for the containers <8, 23) at the level of said work table.