EP0069011B1 - Apparatus for applying and centering a thermoplastics sleeve around an article by means of a vertical member provided with a floating mandrel - Google Patents

Abstract

An apparatus for fitting and centering a sheath such as a thermoplastic sleeve about an object comprises a vertically floating mandrel about which the sheath is fed downwardly toward the object which is to be sheathed. The mandrel is provided with a hollow passage in its lower portion to receive a normally vertically movable member, the vertically movable member carrying at its normally lower end a mold member adapted to engage the head of the object which is to be sheathed, so as to guide and center the transfer of the sheath to the object. The mandrel is provided with a recess opening inwardly from its exterior periphery and into communication with the hollow passage providing a first element lying in the recess and connected to the vertically movable member, so that movement imparted to the first element and causes movement of the vertically movable member, a second element, a drive means located exteriorly of the mandrel for driving the second element. The drive means is operable to move the second element from a location exterior of the mandrel into engagement with the first element, and for subsequently moving the second element while in engagement with the first element to cause lowering of the vertically movable member and the mold member carried by the vertically movable member from an initial elevated position, thereby causing the mold member to engage the head of the object which is to be sheathed.

Description

The present invention relates to the field of equipment intended for laying around objects, including various containers and containers, of sections of sheath or sleeves derived from a flat sheath of heat-shrinkable plastic. It especially relates to a process of the floating mandrel type for fitting and centering sleeves, in an automatic machine supplied with a flat continuous sheath of heat shrinkable plastic, whether or not printed.

It is known that numerous operational steps are necessary to pass, in the abovementioned technique, from the thin sheet of heat-shrinkable plastic material (for example polyvinyl chloride) and shaped in a flat sheath or continuous sheath, to the container provided with its covering. , usually decorated.

Various machines have been described for automating these steps, such as for example the apparatus which is the subject of the European patent published under the number 0 000 851 (deposit n ° 78 400 045.7). According to a particularly advantageous embodiment, the machine for fitting sleeves from a continuous thermoplastic sheath is constituted by a vertical assembly with floating mandrel provided with a narrowing along its length where it is supported by the cooperation of bearings and rollers in the aim of continuously ensuring the following operations: widening of the flat continuous sheath coming from a roll feed, introduction onto the mandrel, downward transfer of the shaped sheath, cutting of the latter into sheath sections or sleeves adequate predetermined length and deposit sleeves around the containers to be coated and / or to be decorated (patent application EP.A.0048656).

Such a floating mandrel assembly is satisfactory and allows very high rates of fitting sleeves. However, the reliability of a perfect transfer of the sheath (before cutting) on the container is not total in a certain number of cases. For example, the container may not be perfectly centered under the mandrel. On the other hand, problems arise when the shape of the container is such that the distance between the base of the mandrel and the top of the body of the container is quite large (for example neck bottle or neck); or when the diameter of the container is maximum at the top (for example set with a tin can), which requires a maximum opening of the sheath section at the time of installation and then causes difficulties for the adjustment of this section around the container with a slightly smaller diameter.

US-A-2 846 835 discloses a device for installing and centering a sheath around an object which comprises a vertically floating mandrel, supported by lifting means and provided in its lower part a vertically movable part, and means for actuating the movable part from the outside. According to this patent, the sheath material is pinched between pliers pivotally mounted and the vertically movable part, which has the shape of a sleeve sliding on the mandrel inside the sheath. The pliers are lowered so that the lower end of the mandrel covers the head of the object, the sleeve follows the movement of the pliers, and a section of sheath is thus lowered onto the object.

According to a variant of this patent, the sheath is lowered by being pinched between rollers and movable fingers located inside the sheath. However, such a device is disadvantageous in that the sheath is not free from any movement, which can be annoying when the device comprises sheath advancing means clocked. In addition, to cover the head of the object, the mandrel must be lowered entirely on said head, which is often impossible or undesirable in practice.

We also know from patent FR-A-2300009 a machine for laying a stretchable or elastic band around a group of objects. According to this patent, an interior chassis is driven vertically from the outside through a belt, using roller means cooperating through said belt. However, in this patent again, the descent of the interior chassis is carried out from the exterior. without the belt retaining its autonomy.

The object of the present invention is to obviate the aforementioned drawbacks and to propose a device for laying and centering a sheath on an object in which provisional continuity can be ensured between a mandrel and the head of said object from the outside without obstructing the free movement of the sheath, often controlled by an independent device without having to lower the entire mandrel onto said object.

To this end, the present invention relates to a device for fitting and centering a sheath or a thermoplastic sleeve around an object according to claim 1 appended.

According to another aspect, the present invention relates to a device for installing and centering a sheath or a thermoplastic sleeve around an object according to claim 4 appended.

• Figure 1: une vue de profil, partiellement en coupe, d'un mandrin flottant muni de perfectionnements selon l'invention:
• Figure 2: une vue agrandie, de face de la partie A de la figure 1
• Figure 3: une vue de détail, agrandie, de la zone B de la figure 1
• Figure 4: la représentation schématique, de profil, de ladite partie A avec indication de moyens mécaniques extérieurs au mandrin destinés à entraîner la pièce mobile à empreinte à l'intérieur de celui-ci.
• Figures 5 et 6: diverses variantes de réalisation des parties médiane et inférieure du dispositif de la figure 1.

The invention will be better understood from the detailed description of nonlimiting embodiments illustrated by the appended drawings which schematically represent:

• Figure 1: a side view, partially in section, of a floating mandrel provided with improvements according to the invention:
• Figure 2: an enlarged front view of part A of Figure 1
• Figure 3: an enlarged detail view of area B in Figure 1
• Figure 4: the schematic representation, in profile, of said part A with indication of mechanical means external to the mandrel intended to drive the movable part with impression inside of it.
• Figures 5 and 6: various variant embodiments middle and lower parts of the device of FIG. 1.

As shown in FIG. 1, the device is part, as the main member, of an automatic machine continuously supplied by a flat sheath of heat-shrinkable plastic and intended to carry out the successive operations of opening the sheath, transfer of the latter to a cylindrical mandrel here with speed programming, removal and cutting of the sheath into sections or sleeves of predetermined length around the container to be sleeved then heat shrinking with a heating device mounted for example on an endless conveyor. The sheath supply means and those for heat shrinking can be, for example, those described in European patent No. 0 000 851.

The floating mandrel 1, the middle and bottom parts of which can be seen in FIG. 1, is designed according to a known general principle described in patent application EP-A-0048656. Inside the constriction 2, the driving drive rollers 3 and 4 come into contact with the bearings of the abutment 5 and 6 and serve both to keep the mandrel 1 in vertical lift and to drive the thermoplastic sheath 7 down. The part of the mandrel located under the constriction 2 is hollow and provided with a movable part, for example here of the piston type 8 at the lower end of which is fixed a hollow imprint 9 intended to see the head of the object to be capped. sleeving (not shown). In the aforementioned French patent, the movement of this piston was controlled by induction by means of an electrostatic coil of dimension slightly greater than the mandrel.

According to the invention, the moving part is driven from outside the mandrel by purely mechanical means. In the case illustrated in Figures 1 to 4, the rod 10 of the movable part, provided at its lower part with a spring sheath 11, comprises a pair of rollers 12 (only one is shown in Figure 1) which cooperate , by momentary contact, with the rollers 13 operated from the outside of the mandrel, the latter having a recess 14 in the zone of action of said rotary elements. Thus, the mandrel remaining fixed in position during work, the internal movable part is driven from the outside with its centering imprint 9 in an up and down movement, at a predetermined rate, with automatic return to the high position by the action. of spring 11.

As can be seen in very diagrammatic FIG. 4, the rollers 13 are carried by support arms 15 which, by virtue of an associated device provided with a cam and not shown here, perform a so-called "square" movement comprising the phases following: approach of the mandrel horizontally until contact with the rollers 13 and rollers 12, descent along the mandrel during the pressing of 13 on 12 (the sheath 7 moving between these two bearings), then spacing horizontally arms 15 to allow the imprint 9 to rise on the base of the mandrel 1 by the action of the spring 11 and, finally, rise of the support arms 15; the cycle repeating again as said above. The distance or value of spacing of the arms 15 is adjustable as a function of the diameter of the mandrel and the length of descent of the arms along the mandrel is that corresponding to the distance between the head and the body of the container to be sleeved.

In practice, the output of the impression 9 from the base of the mandrel 1 takes place just before the triggering of the descent of the sheath 7 on the mandrel. Once this descent is started, the container is capped over the impression with the sheath, the support arms (15) are moved aside and, under the effect of the spring 11, the impression is glued onto the mandrel.

When the impression 9 is capped on the container to be sleeved, it must remain for a certain time in this position to allow the sheath to pass the critical point in its descent along the container. This critical point can correspond for example to the distance between the head and the body of the container or to a particular conformation of the top of the container (set with a can ... etc). The sheath is cut into sections or sleeves by a device already known per se and not shown (see for example the aforementioned European patent) when the sheath has arrived at the bottom of the container.

In this exemplary embodiment, the timing of the internal movable part of the mandrel is ensured, at the level of the piston 8, by a double set of lip points 16 and 17-clearly visible in Figure 3-which oppose the ascent immediate of the rod 10 when the imprint 9 is in a timed position for capping the container to be sleeved. This seal device can be replaced by a system with equivalent function, such as for example a counterweight with thread.

Other embodiments and variants fall within the scope of the general method of the invention and will be briefly described below.

First of all, it is possible to implement in the device of FIGS. 1 and 2 a single series of roller 12 and roller 13 as well as a single support arm 15, the assembly therefore being arranged on one side of the floating chuck 1.

Furthermore, the support arm 15 may not pivot and move away from the mandrel 1 during the ascent of the impression 9. In this case, the caster 13 remains permanently in contact with the roller 12 not only during the descent of the sleeve but also during the ascent of the imprint 9. In such an operation, it is the power of the spring 11 which allows the contact between 12 and 13 to be maintained. In this operational variant, it is possible to provide either a single roller pair / roller - the roller being connected to the support arm - this on one side of the floating mandrel, or else two couples, one and the other are arranged on each side of this mandrel. Such an embodiment is illustrated in FIG. 5.

In accordance with another particularly advantageous variant, illustrated in FIG. 6, the support arm 15 can no longer be connected to a single roller 13 but to two rollers, high and low, numbered 13 and 13 ′ and which trap the internal roller 12, the upper roller 13 ensuring the descent of the sleeve while the lower roller 13 'ensures the ascent of the imprint or cap after depositing the sleeve on the container. In this embodiment, the return spring 11 of the imprint 9 can be omitted and a series of double rollers and of the roller can be provided either on one side of the mandrel (as in FIG. 6) or on two opposite sides on the same horizontal plane. The removal of the spring makes it possible to eliminate any phenomenon of inertia and the imprint (9) can remain in contact on the top of the container all the time that is desired, this time being determined by the cam mentioned above whose the profile is adapted to maintain the imprint on the container for a predetermined sequential period. Furthermore, the device 8 of FIG. 1, for delaying the moving part of the mandrel, is then no longer necessary.

Finally, according to yet another variant of the device shown diagrammatically in FIG. 1, the aforementioned systems of support arms / rollers / rollers can no longer be arranged below all of the bearings (designated 3-4; 5-6) which are used to hold the mandrel (1) in vertical lift but just as well above this assembly.

Claims (5)

1. Device for fitting and centering of a sheath or a thermoplastic sleeve (7) around on object, of type comprising a vertically floating mandrel (1) supported by sustentation means (3-6) and provided in its lower part with a vertically movable part (8-12) and means (13, 13', 15) for actuating the movable part from the outside, characterized by the fact that, on the lower end of the movable part is fastened a mold member (9) adapted to engage the head of the object which is to be sheathed and that the means (13, 13', 15) comprise at least a roller (12) locked with the movable part and located in a recess (14) of the mandrel (1), suited to cooperate by contact through the said sheath (7) with at least an associated wheel (13) mounted on a support arm (15) and actuated from the outside of the mandrel in order to lean on, in low position, at a predetermined rate, the roller (12), each roller and wheel being free in rotation to preserve the independance of the movements of the sheath around the mandrel.

2. Device according to claim 1, characterized by the fact that each support arm (15) is pivoting and able to deviate from the mandrel then to come again in contact position between the roller (12) and the associated wheel (13), at a predetermined rate.

3. Device according to claim 2, characterized by the fact that it comprises besides a mean with a return-spring (11) disposed to bring back the movable part in a high position subsequently to the movement to the low position exerted by the actuating means (12, 13, 15).

4. Device for fitting and centering of a sheath or a thermoplastic sleeve (7) around an object, of type comprising a vertically floating mandrel (1) supported by sustentation means (3-6) and provided in its lower part with a vertically movable part (8-12) and means (13, 13', 15) for actuating the movable part from the outside, characterized by the fact that, on the lower end of the movable part is fastened a mold member (9) adapted to engage the head of the object which is to be sheathed and that the means for actuating comprise at least a roller (12) locked with the movable part and located in a recess of the mandrel (1), suited to cooperate by contact through the said sheath with at least on pair of associated wheels (13,13') mounted on a support arm (15) and actuated from the outside of the mandrel in order to vertically drive the roller in the two directions, at a predetermined rate, each roller and each wheel being free in rotation to preserve the independance of the movements of the said sheath around the mandrel:

5. Device according to claim 4, characterized by the fact that it comprises only one unity support arm (15)-pair of wheels (13, 13')-roller (12), located below or above the sustentation means.

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