GB2167003A - Shaping and feeding sheaths onto vessels - Google Patents

Abstract

In a method for placing sheaths, such as heat shrinkable sheaths, on vessels (14) of non circular section, a sheath is drawn down a circular sectioned, upper mandrel part (10a) by rollers (12), then drawn over a progressively changing section, lower mandrel part (10b) by caterpillers (20, 22) and cut by cutters (16, 18), and when in the desired shape imparted by mandrel part (10b) is ejected onto a vessel (14) by rollers (26). <IMAGE>

Description

SPECIFICATION Method and apparatus for shaping and placing sheaths on vessels The present invention relates in general to processes and devices for placing sheaths on objects such as vessels to be decorated and/or protected and more particularly to the sheathing processes and devices known as the floating mandrel type.

In known packing techniques and in particular as described in French Patent 2,490,590 a sheathing device comprises a chaping mandrel held in position by roller means interacting with one another via a continuous sheath. Cutting means are provided for the purpose of cutting up the continuous sheath into separate pieces, while a portion by which the mandrel is prolonged below the said cutting means enables the pieces of sheathing to be guided one after the other towards the vessels to be sheathed.

It has been found that when the cross section of the vessels on which the sheaths are to be placed is not perfectly circular but includes edges or comprises portions with a reduced radius of curvature it is difficult to shape the sheaths, initially cylindrical in the upper part of the mandrel, in order to fit them to the extension having an angular cross section of the said type. In the conventional systems, when the continuous sheath is caused to move down the mandrel until it is on a level with the cutting device and with the prolongation of the mandrel, of which the cross section progressively adjusts itself to that of the vessels, the said sheath is thrust by suitable driving devices from the top and is thus liable to crumple or become "crammed" during the descent, which is obviously a serious drawback.

The purpose of the present invention is to remedy this drawback and to provide a process and device for shaping and placing sheaths on vessels of non-circular cross section in which the sheath will be enabled to descent in a simple and easy manner before and after the cutting operation, thus eliminating the aforementioned risks.

Accordingly the invention provides means for pulling down the sheath by caterpillar type driving means over the mandrel part which has a changing cross section.

In one aspect of the invention provides a process for placing sheaths on vessels of non-circular cross section, characterized by the fact that it comprises the following stages: pushing a continuous sheath down onto an upper mandrel part by the aid of first driving means provided above a cutting device situated between the upper mandrel part and a lower mandrel part in such a way that the Ic-~er end of the sheath reaches second driving means immediately underneath the cutting device, pulling the continuous sheath downwards by the second driving means until the length of the sheath below the cutting device is equal to that of the required separate pieces, cutting the sheath with the cutting device moving the piece of sheathing thus cut off by means of the second driving means along the lower part of the mandrel towards third driving means 26, and ejecting the piece of sheathing by means of the driving means 26 onto a vessel.

Another aspect of the invention provides a device for cutting and shaping of sheathing comprising a supported mandrel having an upper part and a lower part, a cutting device between the two mandrel parts, first driving means situated above the cutting device and arranged to push a continuous sheath downwards to a short distance below the cutting device, second driving means situated underneath the cutting device and arranged to draw the continuous sheath downwards, third driving means situated below the second driving means and arranged to eject a piece of sheath which has been cut off.

The invention will be understood more clearly from the following description of a preferred embodiment thereof, given by way of an example and by reference to the accompanying drawings, in which: Figure 1 is a side elevation, in schematic section, of a device for placing sheaths in position according to the invention.

Figures 2a and 2b are cross sections through part of the device shown in Figure 1, along lines A A and B-B respectively.

Figures 3a and 3b are schematic side views illustrating the operation of the device shown in Figure 1.

With reference to the drawing, particularly Figure 1, a device for placing sleeves or sheaths of heatshrinking plastics material around vessels for ornamental and/or protective purposes has been shown schematically. A mandrel, marked 10 as a whole, is supported vertically by conventional roller means, shown schematically at 12, which also function as first driving means for a continuous sheath from which pieces of sheathing are cut in order to be placed individually and in succession on vessels 14 conveyed by suitable conveying means (not shown in the drawing).

As will be seen in detail farther on, the vessels 14 are of polygonal cross section.

The mandrel 10 comprises an upper part 10a and a lower part 10b separated from each other by a cutting device taking the form of a set of blades 16 capable of penetrating a peripheral groove 18 at the junction between the said two parts 10a and 10b.

Along the lower part 10b of the mandrel second driving means are also provided, taking the form of two caterpillar units 20 and 22 driven by upper and lower rollers 24, these latter being themselves driven by suitable transmission means, such as belts, chains etc. (not shown in the drawing) connected to a motor (likewise not shown). The caterpillars 20 and 22 in the present case consist of a flexible material such as rubber, so that the driving action will not damage that part of the sheath with which they are in contact.

Finally, in the zone of the lower bend of the second part 10b of the mandrel third driving means are provided, taking the form of simple rollers 26, likewise selectively driven in rotation by suitable means (not shown).

As shown in Figures 2a and 2b the upper part 10a of the mandrel is of substantially circular cross section while the lower part 10b of the mandrel has a cross section which gradually develops from the top towards the bottom of Figure 1 from a circular shape to the polygonal shape shown in Figure 2b. This polygonal cross section is shaped in such a way that it largely corresponds to the cross section of the vessels 14, and its obvious purpose is to facilitate the transfer of a piece of sheathing from the free lower end of the mandrel to the periphery of a vessel 14 in the sheath mounting operation itself.

As explained farther back, it is often difficult to shape a sheath descending over the mandrel of circular cross section to a polygonal cross section such as that illustrated by simply pushing the sheath by the aid of supporting roller assemblies 12. The fact is that the resistance of the lower part 10b of the mandrel 10 to the advance is such that between the rollers 12 and the said part the sheath is very liable to crumple, thus becoming unusable and causing a disadvantageous interruption in the operation of the entire treatment apparatus.

In this respect the device described for mounting pieces of sheathing remedies this drawback by operating in the following manner, described by reference to Figures 3a-3d.

First of all, in the position shown in Figure 3a, the lower end of a continuous sheath 28 is situated on a level with the cutting device 16 and 18 after a preceding piece of sheathing has been cut off by this latter. From this position onwards the sheath 28 is pushed downwards by the rollers 12, constituting the first driving means, over the very short distance, until its free lower end 28a reaches the upper part of the second driving means 20 and 22 (Figure 3b), these being of the "caterpillar type").

The caterpillars 20 and 22 are then set in motion by their rollers 24 in the direction shown by the arrows 25, in order to pull the sheath 28 downwards, the rollers 12 then being simultaneously moved in to the disengaged position. At this point it should be noted that the sheath is no longer pushed but advantageously pulled onto the lower shaping part 10b of the mandrel. Furthermore, the sheath is accompanied by the caterpillars not at one or more contact points, as would be the case with the rollers, but over a substantial part of its height, thus still further reducing the risk of deterioration in the said sheath.

Once the sheath 28 has been pulled far enough to enable it to extend below the cutting device 16 and 18 over a length corresponding to the desired length of sheathing (Figure 3c), the caterpillars 20 and 22 are immobilized and the said cutting device is actuated in order to cut off the piece of sheathing concerned (marked 28'). The caterpillars 20 and 22 are then once again set in motion in order to establish contact between the piece of sheathing 28' and the rollers 26, which function as ejection means for the said piece, at present in the "waiting" position to eject it onto the associated vessel 14, when this latter has been moved into position below by the aforementioned transport means.

The cycle of operation as described in the foregoing can then recommence in order to shape and cut off the subsequent piece of sheathing (Figures 3a et seq.).

It should also be noted that this process offers the advantage that while the piece of sheathing 28' is in the "waiting" position on a level with the ejector rollers 26, the said piece thus being immediately available as soon as the vessel 14 is in the position to receive it, it is simultaneously possible to carry out the first stage of the process described, consisting of the operation of pushing the continuous sheath 28 until it is on a level with the upper part of the caterpillar unit 20 and 22, this ensuring a by no means negligible saving of time.

The second driving means 20 and 22, of the caterpillar type, can be designed to be selectively moved away from the lower shaping part 10b of the mandrel, either by their upper or by their lower zone or in their entirety, firstly in order to enable the lower end 28a of the sheath 28, not cut off, to be inserted between the mandrel and the said caterpillars during the initial stage, and also in order to enable the "waiting" piece of sheathing 28' to be ejected at a high speed by the rollers 26 while the upper part of the caterpillar unit commences the operation of pulling the continuous sheath 28 downwards (second stage of process) in order to shape it.This object will be advantageously achieved by providing means (not shown inthe drawing) enabling the upper and lower rollers 24 driving the caterpillars to be individually moved sideways in relation to the lower part 10b of the mandrel.

Furthermore, the operations described can be sequenced and synchronized in a suitable manner by an electrical control unit.

Needless to say, the present invention is not limited to the embodiment described and allows of any variation which the technician qualified in this sphere can make thereto in the light of his knowledge.

In particular, the number of rollers 12, 24 and 26 and caterpillars 20, 22 around the periphery of the mandrel will be selected in accordance with the requirements arising and with the resistance offered by the lower part 1 Ob of the mandrel to the descending movement of the sheath. Similarly, the pressure with which the caterpillars are applied against the mandrel can be suitably selected, e.g.

by the aid of adjustable elastic means.

Finally, the shape of the cross section of the lower part 10b of the mandrel may be polygonal or otherwise, as desired.

Claims (11)

1. A process for placing sheaths on vessels of non-circular cross section, characterized by the fact that it comprises the following stages: pushing a continuous sheath down onto an upper mandrel part by the aid of first driving means provided above a cutting device situated between the upper mandrel part and a lower mandrel part in such a way that the lower end of the sheath reaches second driving means provided immediately underneath the cutting device, pulling the continuous sheath downwards by the second driving means until the length of the sheath below the cutting device is equal to that of the required separate piece, cutting the sheath with the cutting device, moving the piece of sheathing thus cut off by means of second driving means along the lower part of the mandrel towards third driving means, and ejecting the piece of sheathing by means of third driving means onto a vessel.

2. A device for cutting and shaping pieces of sheathing comprising: a supported mandrel having an upper part and a lower part, a cutting device between the two mandrel parts, first driving means situated above the cutting device and arranged to push a continuous sheath downwards to a short distance below the cutting device, second driving means situated underneath the cutting device and arranged to draw the continuous sheath downwards, third driving means situated below the second driving means and arranged to eject a piece of sheath (which has been cut off).

3. A device in accordance with claim 2, in which the lower part of the mandrel has a non circular cross section and is arranged to function as a shaping means for the sheath in order to adapt it to the shape of the cross section of vessels to be sheathed.

4. A device in accordance with Claim 3, in which the lower part of the mandrel has a cross section of which the shape develops progressively from a circle at the top to a polygon at the bottom.

5. A device in accordance with any of claims 2 to 4, in which the second driving means comprise caterpillars rotatable around rollers and capable of extending in a direction substantially parallel to the adjacent walls of the lower part of the mandrel.

6. A device in accordance with claim 5, in which the caterpillars are made of rubber.

7. A device in accordance with either of Claims 5 and 6, in which the caterpillars each circulate between two rollers which may be individually moved closer to and farther away from the lower part of the mandrel.

8. A device in accordance with any of Claims 2 to 7, in which the first driving means also form supporting means for the mandrel.

9. A device in accordance with any of Claims 2 to 8, in which the third driving means consist of rollers.

10. A device for cutting, shaping and placing pieces of sheathing on vessels substantially as described herein with reference to or as illustrated in the accompanying drawings.

11. A process for placing sheaths on vessels substantially as described herein with reference to the accompanying drawings.