Apparatus for applying a removable liner layer in vessels

Abstract: The present invention relates to an apparatus for automatically applying a removable inner liner layer (30), in vessels or containers (31) in general, characterized in that the apparatus comprises, on a base framework (2), a substantially cylindric body (5), thereon there is applied a liner element (30), and having an expansible and resiliently deformale side surface (9), and a top wall (8a), which substantially mates with the inner bottom of a vessel (31) to be lined. The cylindric body (5), at its bottom end portions (6,8), is at least partially housed in a bell body (20), adapted to operate as a holding element for the resilient deformation of the bottom portion of the expansible side wall (9), in order to cause the liner element (30) to adhere to the inner surface of the vessel (31) and to bend the end portions of this liner element (30) on the edge or rim of the vessel.

Description: BACKGROUND OF THE INVENTION The present invention relates to an apparatus for automatically applying a removable inner liner to vessels or containers in general. As is known, in several industiral fields there are frequently used metal vessels, drums, barrels and the like, for the containment and shipment of products of several types, such as alimentary products, chemical products, toxic liquids or powders, paints, glues and the like. Usually, as the contents of the vessel is withdrawn, at least a portion thereof remains adhering to the inner walls of the vessel, thereby it is necessary to remove the remaining materials in order to use again the vessel. This remaining materials must be also removed in the case in which the vessel is not reused but it is disposed of, in order to prevent pollutions to the environment. In order to facilitate the cleaning operations, the inner surface of the vessels is usually coated by a coating layer or liner, conventionally made of plastic material bags, which are usually made of polyethylene or the like. These bags are usually applied by means of manual operations which, in addition to requiring a lot of time, also generate several problems, since, between the inner wall of the vessel and the bag, there are inevitably formed air bubbles, which prevent a good operation of the vessel. In fact, because of the formation of the mentioned air bubbles, the vessel volume for the products is remarkably reduced, and, moreover, the contents can not be fully withdrawn, since a part thereof remains entrapped in folds or the like of the bag. In this connection it should be also pointed out that in regions where there are present air bubbles or folds, the bag material can be easily torn or broken, expecially when, for removing the contained product, there are used collecting metal scraping elements and the like. SUMMARY OF THE INVENTION Accordingly, the main object of the present invention is to solve the above mentioned problems, by providing an apparatus for automatically applying an inner coating or liner layer, of the easily removable type, in vessels in general, which is specifically designed for automatically performing all of the operations for applying said inner liner, while providing a perfect adhesion of the inner liner to the inner surface of the vessel. Within the scope of the above mentioned aim, a main object of the present invention is to provide such an apparatus which also allows the possibility of properly coating also the edge or rim of the vessel, so as to prevent the formation of regions at which leakages can occur between the inner wall of the vessel and the inner liner layer. Another object of the present invention is to provide such an apparatus which also affords the possibility of easily removing the liner, as required, by means of simple operations and in a very reduced time, and which apparatus, moreover, is very reliable and safe in operation. According to one aspect of the present invention, the mentioned aim and objects, as well as yet other objects, which will become more apparent hereinafter, are achieved by an apparatus for automatically applying a removable inner liner layer, in vessels in general, characterized in that said apparatus comprises, on a supporting framework, a substantially cylindric body, to which a liner element can be applied, and having an expansible and resiliently deformable side surface, and a top wall substantially mating with the inner bottom of a vessel to be lined, said cylindric body being partially housed, at the bottom end portion thereof, in a bell body providing a holding or containment element for the resilient deformation of the bottom portion of the expansible side wall, in order to cause the liner element to adhere to the inner surface of said vessel and to bend the end portions of said inner liner on the edge of the vessel. BRIEF DESCRIPTION OF THE DRAWINGS Further characteristics and advantages of the present invention will become more apparent hereinafter, from the following detailed disclosure, of a preferred, though not exclusive, embodiment thereof, which is illustrated, by way of an indicative but not limitative example, in the figures of the accompanying drawings, where: Figure 1 is a schematic partially cross-sectional view, illustrating the apparatus according to the present invention during an operating step in which there is adjusted the location or position of the bell body with respect to the cylindric body; Figure 2 illustrates the apparatus according to the present invention after the application of the inner liner in the vessel; and Figure 3 illustrates an operating step in which the inner liner is caused to perfectly adhere to the inner surface of the vessel. DESCRIPTION OF THE PREFERRED EMBODIMENT With reference to the number references of the figures of the accompanying drawings, the apparatus for automatically applying an inner coating or liner layer, of a removable type, in vessels or containers in general, according to the present invention, which has been indicated generally at the reference number 1, comprises a supporting framework 2, on which there is arranged a supporting structure 3, on the top of which there is located a cylindric body, generally indicated at the reference number 4, comprises a rigid material cylindric drum 5, which is closed at the end portions thereof, by a bottom plate 6 and a top plate 7. Adjoining the plate 6 and 7, there are provided a bottom and top counter-plate, indicated respectively at 8 and 8a, which can be mutually clamped so as to tightly hold the end portions of a tubular membrane 9 made of a resiliently deformable and expansible material. The tubular membrane 9 provides, in cooperation with the rigid drum 5, a gap 10 which communicates with a pressurized air source, through a nozzle 11, leading to the rigid drum 5 and connected to the pressure source by means of a pipe 12. With the support 3 there is associated a bell body 20 which is arranged at the bottom portion of the tubular membrane 9 and is adjustably supported, in order to in turn adjust the position of the bell body, with respect to the free edge or rim of the vessel, as it will become more apparent hereinafter. In a not limitative embodiment, the means for adjusting the height of the bell body 20, comprise a disc 21, including a threaded hole 22, which is supported by the support 3 and engages with a rotary threaded shaft or spindle 24, in turn axially supported in said drum 10 and adapted to be connected with a removable crank 25. The disc 21 is connected to an annular body 23, therefrom extend radial pins 27, passing through slots 28 of the support 3, and connected to the bottom portion of the bell body 20, which can be displaced vertically, by causing the threaded spindle or shaft 24 to rotate. On the cylindric body 4, an inner liner can be applied, said liner comprising a polythene or the like material bag 30, and, after the application of said bag, the vessel 31 can be assembled, so as to assume one of several conventional configurations. In this connection it should be pointed out that the top plate has preferably a shape mating with the inner bottom of the vessel or container 31. In order to hold the vessel 31 in its set position, there is provided a sealing plate 40, which is supported by a radially extending arm 41, coupled to a column post 42, thereon there are arranged all of the drive means of the apparatus. The arm 41 can rotate with respect to the mentioned post, so as to cause the sealing or tightness plate 40 to be moved away, as the vessel must be applied or removed, whereas said plate 40 will be properly located and pressed on the bottom of the vessel during the operating steps of the apparatus. In operation, it is necessary to at first adjust the height position of the bell body 20, so as to provide a small gap between the bottom free edge of the container and the edge of the bell body. Then, the inner liner element 30 is applied, comprising a bag or the like, and, above the latter, there is assembled the vessel 31 as is clearly shown in figure 2. Then, pressurized air is supplied inside the bag 10, so as to resiliently deform the tubular membrane 9, which perfectly adheres on the inner wall of the vessel, and so as to cause the inner liner to also perfectly adhere, said inner liner being firmly held since, because of the withdrawing of the air, there is provided a sucker type of effect. At the free edge thereof the tubular membrane, which is not herein counterbiassed by the vessel, will be dilated, so as to contact the mentioned bell body, which will operate as a holding or containment element, and, in actual practice, will provide an upwardly turned portion, as clearly shown in figure 3, which will cause the free end portion of the liner to be outwardly turned on the outer rim of the vessel, so that the inner element will perfectly adhere to the walls of the vessel. After having obtained this adhesion, the pressure is removed from the gap 9 and, then, after having also removed the plate 40, the vessel will be withdrawn with the liner perfectly adhering thereon, since the adhesion has been obtained by means of an even pressure effect applied on the overall surface of said liner, owing to the resilient expansion of the membrane. From the above disclosure it should be apparent that the invention fully achieves the intended aim and objects. In particular, the fact is to be pointed out that, by exploiting the resilient expansion of a membrane, it is obtained a perfect coupling of the inner liner to the inner wall of the vessel, independetnly from the configuration of the latter which can be both of cylindric shape, conic shape, any possible air bubbles between the liner and wall of the vessel being prevented from occurring. The invention as disclosed is susceptible to several modifications and variations all of which will come within the scope of the claims. Thus, for example, the means for positioning the bell body with respect to the cylindric body can be of any suitable types, such as pneumatic pistons or the like. In practicing the invention, the used materials, as well as the contingent shapes and size can be any according to requirements.

Claims: An apparatus (1) for automatically applying a removable inner liner layer (30), in vessels (31) in general, characterized in that said apparatus comprises, on a supporting framework (2), a substantially cylindric body (4), to which a liner element (30) can be applied, and having an expansible and resiliently deformable side surface (9), and a top wall (8a) substantially mating with the inner bottom of a vessel to be lined, said cylindric body being partially housed at the bottom end portion thereof, in a bell body (20) providing a holding or containment element for the resilient deformation of the bottom portion of the expansible side wall, in order to cause the liner element to adhere to the inner surface of said vessel and to bend the end portions of said inner liner on the edge of the vessel. An apparatus, according to Claim 1, characterized in that said supporting framework (2) supports said cylindric body (4) and a shaft to which there is rotatably coupled an arm (41), supporting in turn a plate (40) which can be engaged with the outer bottom of the vessel to be lined. An apparatus, according to Claims 1 and 2, characterized in that said cylindric body (4) comprises a rigid drum body (5) having, at the end portions thereof, a bottom plate (8) and a top plate (8a) facing, respectively, a bottom counterplate (6) and top counterplate (7), between said plates and counterplates being restrained the axial end portions of a tubular membrane (9), which constitutes the expansible side surface. An apparatus, according to one or more of the preceding claims, characterized in that said tubular membrane (9) defines, in cooperation with the outer surface of the rigid drum, a tightly closed gap (10) which communicates with a pressurized air supply nozzle (11). An apparatus, according to one or more of the preceding claims, characterized in that said bell body (20) is connected to said support through the interposition of height adjusting means, for changing the position of the bell body (20) with respect to said cylindric body (4). An apparatus, according to one or more of the preceding claims, characterized in that said height adjusting means comprise a disc (21) having a threaded central hole (22) therein there is engaged a threaded spindle (24) axially extending in said drum body (4), said disc (21) being connected to a ring therefrom radial pin (27) project, said pins being slidably housed in slots (28) of said supports and engaging with said bell body (20). An apparatus, according to claims 2 to 6, characterized in that said plate (40), by engaging the outer bottom of said vessel, holds firmly said vessel in a said position, during the resilient expansion step of said tubular membrane (9).

Inventors: D ALEO MARIA PIA, D'ALEO, MARIA PIA
Applicants: PLASTIBAG SRL, PLASTIBAG S.R.L.
Application year: 1992
Main classification: B29C63
IPC codes: B29C63, B29C57