FR2816929A1 - Method for conveying thin articles comprises introduction of article into guide channel and using air jets directed through longitudinal opening in obstacle transverse to article principal surfaces - Google Patents

Abstract

The thin article, such as a lid (1) whose principal faces are connected by a small size section (1b), is introduced into a guide channel (3) and is projected in a given direction by air jets. During transport an obstacle is made in a transverse direction to the article's principal surfaces (1a,1c) with guide means (4) comprising a continuous longitudinal opening (F). The air jets are directed on the article small section.

Description

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 The present invention relates to the field of on-line transport of thin articles under the action of transport air jets. It relates to a method of transporting thin articles by means of air jets. It preferably, but not exclusively, finds its application to the transport of thin disc-shaped articles, and more particularly to the transport of covers of cylindrical cans for the packaging of beverages.

In the present text, the term “thin article” designates any rigid or semi-rigid object of small thickness. In general, a thin article can be defined as an object having two main faces, connected by a portion of small dimension compared to the dimensions of its two main faces, said portion being designated slice in the present text. It is for example a cover in the form of a disc, plastic, cardboard, or metal, used in the packaging industry to close a cylindrical box, such as for example a can for packaging a drink. The invention is however not limited to an article in the form of a disc, and finds its application in the transport of thin articles whose main faces of larger dimension can have any type of geometry, and for example a polygonal shape. . Also, a main face of a thin article is not necessarily flat, but may have a curved shape. The thickness of the edge of a thin article can indifferently be constant or not. As will appear more clearly with reference to the accompanying drawings, in the present text, the term thin article may also designate an object of small thickness, having a protuberance projecting transversely relative to one of its main faces; it is for example a box cover fitted with a straw, such as that described in French patent application FR-A-2,573
046.

 A first known solution for transporting articles

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 thin under the action of air jets is described for example in patent US-A-3, 210, 124. This solution consists in using an air conveyor having a flat blower bottom surface, on which the articles are transported in being positioned flat, that is to say with one of their larger face (main face) oriented towards the blowing surface. This blowing surface is provided with slots or orifices, and air jets are generated through these blowing slots or orifices which simultaneously make it possible to support and transport the articles in a given direction of transport parallel to the blowing surface. The air jets for lift and transport exert a pushing action on the lower main face of the thin articles. During transport, the thin articles are also guided one behind the other in a channel, which comprises the aforementioned blowing surface ensuring a lower guiding, upper guiding means constituted for example by parallel tubes mounted above the blowing surface , and lateral guide means (left and right) constituted for example by two lateral vertical guide walls arranged on either side of the path of the articles. The articles are transported one behind the other (in single file) inside this guide channel. The width of this guide channel, which corresponds to the distance separating the two lateral guide walls, is chosen so as to prevent two successive articles from being aligned laterally with respect to the direction of transport, the lateral guide walls thus preventing overflow of articles. The height of the guide channel, which corresponds to the distance separating the blowing surface and the upper guide means, is chosen to be sufficiently small compared to the thickness of the articles transported to avoid any risk of overlapping of two articles during transport.

 This transport solution may seem attractive at first glance, because in theory it suffices to adjust the lift air jets judiciously, in relation to the weight of the articles transported, to

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 transport the articles, preventing their lower main face from coming into contact with the conveyor. In practice, this adjustment is very delicate, and above all sensitive to the smallest air disturbances (variations in pressure or air flow in the air supply means), so that it frequently happens that the articles transported rub against the blowing surface for example, which can prejudicially lead to damaging one of the main faces of the articles.

 A second known solution for transporting thin disc-shaped articles under the action of air jets is described, for example, in US Pat. No. 3,734,567. In this solution, we find the implementation of a guide channel inside which the thin articles are transported one behind the other under the action of transport air jets generated in the direction of one of their main faces.

Unlike the first aforementioned solution, the articles are oriented substantially vertically, their thinner edge being placed on a lower rolling plane. Under the action of transport air jets, thin disc-shaped articles roll on their edges on the surface of this lower plane. This solution with rolling movement of the articles, on the one hand is only possible for disc-shaped articles, which limits its applications, and on the other hand does not allow transport of the articles at high speed.

 Also, the two aforementioned transport solutions have the drawback of being able to be used only with thin articles without transverse protuberance, and in particular do not allow the transport of lids fitted with a straw such as those described in the French patent application. FR-A-2 573 046.

 The object of the present invention is to propose a new solution for transporting thin articles, which makes it possible to meet all or part of the following constraints: - to allow transport of thin articles whose main faces may have a varied geometry, and not just a form

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 circular, - allow the transport of thin articles which may or may not have a protrusion extending transversely to one of their main faces, without having to modify the conveyor, - allow the transport of thin articles stably and at a rate high, - allow the transport of thin articles without wear or deterioration of the articles.

 This object is achieved by the invention which relates to a new method of transporting a thin article comprising two main faces connected by a small dimension. According to this method, in a known manner, in particular by patent US-A-3,210,124, the article is introduced into a guide channel and the article is propelled inside this channel in a given direction of transport, by means of air jets.

 Characteristically according to the invention, during transport, movement of the article is prevented in a direction transverse to its two main faces, with guide means comprising a continuous longitudinal opening, the air jets of transport being directed on the edge of the article.

 Preferably, the air jet streams are generated in the opening of the guide means and the article is positioned so that its edge is positioned in the opening.

 Other characteristics and advantages of the invention will appear more clearly on reading the description below of two alternative embodiments of a conveyor of thin articles according to the invention, which description is given by way of example limiting and with reference to the accompanying drawings in which: - Figure 1 is a perspective representation of a conveyor part according to a first embodiment of the invention, - Figure 2 is a side view (in a vertical plane transverse to the direction of transport of the articles) of the conveyor of FIG. 1,

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convoyeur des figures 1 ou 3, et - la figure 6 est une vue en coupe transversale du guide de la figure 5 selon le plan VI-VI. - Figure 3 is a perspective representation of a conveyor part according to a second alternative embodiment of the invention, - Figure 4 is a side view (in a vertical plane transverse to the direction of transport of articles) of conveyor of Figure 3, - Figure 5 is a perspective representation of a guide of the

conveyor of Figures 1 or 3, and - Figure 6 is a cross-sectional view of the guide of Figure 5 according to the plane VI-VI.

FIG. 1 shows a first alternative embodiment of an air conveyor according to the invention, which in the illustrated example is used to transport in line in the transport direction T, lids 1 made of metal, light, and intended to be assembled, on cylindrical cans type cans, to ensure watertight closure.

In Figure 1, only a short portion of the conveyor is shown, it being specified that such a conveyor extends identically over several meters. The covers 1 are introduced automatically at the entry of the conveyor by a known machine (not shown), and its routed one after the other in the conveyor under the action of air jets, to a downstream machine (not shown), performing for example the automatic assembly of each cover on a cylindrical box.

1a du couvercle 1. La paroi de fond 1a et à l'opposé le rebord 1c définissent respectivement les deux faces principales du couvercle 1. La paroi latérale 1b reliant ces deux faces principales forme la tranche du couvercle. Referring to Figure 2, usually, a cover 1 is a part having a bottom wall 1a forming a disc of diameter d, which is extended by a substantially cylindrical side wall 1b of small height ei (generally less than 10mm) .
This side wall 1b is extended opposite the bottom 1a by a circular rim 1c of diameter D, slightly greater than the diameter d of the bottom

1a of the cover 1. The bottom wall 1a and opposite the rim 1c respectively define the two main faces of the cover 1. The side wall 1b connecting these two main faces forms the edge of the cover.

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 With reference to FIGS. 1 and 2, in a first alternative embodiment the conveyor comprises guide means 2, 2 ′ which form over the entire length of the conveyor a channel 3 for mechanically guiding the covers 1.

 The guide means 2 make it possible to support and guide the covers 1 laterally during transport, and also to generate jets of transport air (symbolized by the arrows J in FIG. 2) directed on the thin section 1b covers. More particularly, the guide means 2 are produced by means of spaced lower guides 4. These guides 4 have a spacing such that a longitudinal and continuous opening F is formed over the entire length of the conveyor.

 The guide means 2 'are mounted opposite the lower guides 4, and comprise two elongated stops 5 parallel. In another variant, these elongated stops 5 could be replaced by a single stop 5 positioned for example in a median plane relative to the two lower guides 4, or also by a guide wall mounted above the opening F.

 More particularly, with reference to FIGS. 5 and 6, a guide 4 consists of a plate of length L, of thickness e and of width t, preferably made of plastic. In practice, the length L is small compared to the length of the article transport path (length of the conveyor); consequently, to guide the articles transported over the entire length of the conveyor, several lower guides 4 such as that of FIG. 5 are used, mounted end to end one behind the other. In one 4a of the main faces of this plate, which corresponds to the upper face of the guide 4 when the latter is mounted on the conveyor, a longitudinal bowl 4b is produced, making it possible to release from the mass of the plate a longitudinal bearing surface 4c of small dimension, and forming a rounded edge of very small radius of curvature. In the plate is formed a longitudinal cavity of

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distribution d'air 4d qui est débouchante dans la face supérieure 4a de la plaque. Dans la face latérale 4f de la plaque, qui prolonge la surface porteuse 4c, sont ménagés une pluralité d'orifices de soufflage 4g répartis sur la longueur de la plaque. Chaque orifice de soufflage 4g communique avec la cavité de distribution d'air 4d par un canal de soufflage 4e.

air distribution 4d which opens into the upper face 4a of the plate. In the lateral face 4f of the plate, which extends the carrying surface 4c, a plurality of blowing orifices 4g are arranged distributed over the length of the plate. Each blowing orifice 4g communicates with the air distribution cavity 4d by a blowing channel 4e.

de la paroi inférieure 6a d'une gaine, et que la cavité de distribution 4d d'un guide 4 soit positionnée en vis à vis d'une lumière 7. With reference to FIGS. 1 and 2, for the production of transport air jets, the conveyor comprises two air distribution ducts 6, longitudinal and parallel, which are usually supplied with pressurized air by means of a plurality of fans (not shown) judiciously distributed over the length of the ducts 6. The bottom wall 6a of each distribution duct 6 is provided with a plurality of openings 7 of dimension similar to that of the distribution cavity 4d of a guide lower 4. Each lower guide 4 is fixed to the lower wall of a longitudinal sheath 6, so that the upper face 4a of a guide 4 is applied in leaktight manner against the lower face

of the lower wall 6a of a sheath, and that the distribution cavity 4d of a guide 4 is positioned opposite a light 7.

F, entre et à proximité immédiate des deux faces de soufflage 4f des guides 4. Le rebord 1c de chaque couvercle se trouve positionné à proximité des guides supérieurs 5. The method of transporting the covers 1 with the conveyor of Figures 1 and 2 will now be detailed. The covers 1 are successively introduced, one after the other, into the guide channel 3 of the conveyor while being in the horizontal position illustrated in FIGS. 1 or 2. Once introduced into the conveyor, each cover 1 is supported by the guides lower 4, the rim 1c of a cover coming into contact with the bearing surfaces 4c of the guides 4 opposite. The edge of the covers (side wall lb) is positioned in the opening

F, between and in the immediate vicinity of the two blowing faces 4f of the guides 4. The flange 1c of each cover is positioned near the upper guides 5.

 Prior to the introduction of the covers, the conveyor fans are started and supply pressurized air to each distribution duct 6. Each distribution cavity 4d of each guide

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 4 is thus also supplied with pressurized air, the air passing through the ports 7; this pressurized air passes through the blowing channels 4e, and escapes, in the form of transport air jets J, through the blowing orifices 4g. These transport air jets J are generated on either side of the covers, near and at the edge 1b of each cover 1.

 With reference to FIG. 5, the orifices 49 and blowing channels 4e are oriented relative to the direction of transport T, so that the air escapes from a blowing orifice in the form of a jet d air directed towards the articles and in the direction of transport (figure 5 / arrow V symbolizing the velocity vector of an air jet). Thus, in operation, the transport air jets J apply tangential thrust forces on the edge 1b in the transport direction T, which make it possible to slide the covers one behind the other in the transport direction T .

 Knowing that the contact surface between the covers 1 and the guides 4 is very low, the friction is very low, and it is possible to convey the covers 1 at high speed. As an indication, it is possible to obtain a rate of supply of the machine at the outlet of the conveyor greater than 2000 covers / minute.

 During transport, the covers 1 are guided laterally on either side by the blowing faces 4f of the guides 4, these blowing faces 4f acting as a stop for the edge 1b of the covers and thus opposing displacement of a cover in a horizontal plane and in a direction transverse to the direction of transport T. The guide means 2 (lower guides 4) also make it possible to generally prevent movement of the covers in a transverse direction at their main faces, the bearing surfaces 4c of the guides 4 serving as stops for the edges 1c of the covers 1. The guide means 2 ′ (high stops 5) also generally make it possible to obstruct movement

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 covers in a direction transverse to their main faces. More particularly in the example illustrated, the stops 5 oppose an upward movement of the covers, the rim 1c of a cover 1 coming into contact with the stops 5 in the event of the cover coming off relative to the lower guides 4. These stops 5 serve as a guardrail and make it possible to avoid excessive detachment of the covers relative to the guides 4 under the action of the transport air jets. In particular, these upper stops 5 are positioned close enough to the lower guides 4, to prevent two successive covers from overlapping during transport. It is thus possible to obtain stable and high-speed transport of the covers.

 Preferably, but not necessarily, the conveyor is further equipped with a lower cover making it possible on the one hand to protect the transported covers, in particular against dirt from the air surrounding the conveyor, and on the other hand to channel the transport air flow generated to make the action of the air jets more effective. Referring to Figure 1 or 2, this lower cover comprises two walls 8 fixed opposite one another under the lower guides 4 and delimiting under the articles a space 9 for channeling air.

 Also the conveyor is advantageously covered in the upper part by means of a wall 10, substantially in the shape of an inverted U in the particular example illustrated, and mounted on the upper walls of the two distribution sheaths 6. The guide means 2 'are positioned between the two distribution ducts 6, and surmounted by the cover 10.

 There is shown in Figures 3 and 4 another variant of air conveyor, which is used to transport covers 1 equipped with a straw 1d. This type of article is also very widely known, and described for example in French patent application FR-A-2,573,046.

 The straw 1d forms a protruding element relative to the bottom 1a of the cover, extending in a direction generally transverse to the

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1d ne rencontre d'obstacle venant gêner son déplacement. bottom of the cover. Thanks to the presence of the continuous opening F between the lower guides 4, the covers 1 can be introduced into the guide channel 3 by passing their straw 19 through the opening (F), and can move along the lower guides 4 without their straw

1d does not encounter an obstacle that would impede its movement.

1e de la paille. Preferably, but not necessarily, a left and right lateral guiding of the straw is also ensured during transport, by means of two lateral guides 11, which extend over the entire length of the conveyor, and which make it possible to guide the part substantially vertical

1st of the straw.

 The invention is not limited to a method of transporting covers, but can be applied to the transport of any thin article.

 In the two particular embodiments described with reference to the accompanying drawings, the articles are transported in a horizontal position, that is to say so that their main faces (1a, 1c) are substantially in a horizontal plane. This characteristic is not however limiting of the invention; in another alternative embodiment of the invention, the thin articles could be transported in an upright position.

en étant supportés par leur rebord 1 c, et avec leur fond 1a orienté vers le bas. Cette caractéristique n'est pas limitative de l'invention ; dans une autre variante de réalisation de l'invention, les couvercles peuvent être transportés en position retournée, c'est-à-dire avec leur fond 1a orienté vers le haut. Dans ce cas, lorsque les couvercles 1 comportent une paille

1 d, celle-ci se trouve orientée vers le haut et il faut modifier le convoyeur de telle sorte que les moyens de guidage supérieur 2'présentent une ouverture longitudinale (F) continue, à travers laquelle la paille peut circuler. Also, in the two particular embodiments described with reference to the accompanying drawings, the covers are transported

being supported by their edge 1 c, and with their bottom 1a facing downwards. This characteristic is not limiting of the invention; in another alternative embodiment of the invention, the covers can be transported in the inverted position, that is to say with their bottom 1a facing upwards. In this case, when the covers 1 have a straw

1 d, the latter is oriented upwards and the conveyor must be modified so that the upper guide means 2 ′ have a continuous longitudinal opening (F), through which the straw can circulate.

 In the two particular embodiments described in

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 with reference to the accompanying drawings, transport air jets (J) are used which are generated on either side of the articles transported. This characteristic is not, however, limiting of the invention. In another variant embodiment of the invention, it is conceivable to generate transport air jets on the edge of the thin articles on a single side of the articles. Also, it is conceivable to modify the conveyor of FIGS. 1 or 3 so that one of the air distribution ducts 6 is used to supply air to a lower guide 4 so as to generate jets of transport air. in a given direction of transport (T), and that the other air distribution ducts 6 be used to feed the other lower guide 4 opposite so as to generate reverse air jets in an opposite direction to the direction of transport T; it suffices to modify the orientation of the 4th channels and the blowing orifices 41 9 of the lower guides 4 on the left (or right). A conveyor is thus obtained which is easily reversible as regards the direction of transport of the articles; also the reverse air jets can for example be used to aeraulically brake the articles transported.

Claims (6)

 1. Method for transporting a thin article (1) comprising two main faces connected by a small section (1b), according to which the article is introduced into a guide channel (3) and the article is propelled into a direction of transport (T), by means of transport air jets, characterized in that an obstacle to a movement of the article (1), in a direction transverse to its main faces, is prevented guide (2) having a continuous longitudinal opening (F), and in that the transport air jets (J) are directed on the edge (1 b) of the article. 2. Method according to claim 1 characterized that the transport air jets (J) are generated in the opening (F) of the guide means (2), and the article (1) is positioned so that its edge (1b) is positioned in the opening (F). 3. Method according to claim 1 or 2 characterized in that the article (1) has a protrusion (1d) projecting transversely to one (ta) of its two main faces, and in that it is positioned in the guide channel (3) so that this protuberance 1d passes through the opening (F). 4. Method according to claim 3 characterized in that a lateral guidance of the protuberance (1d) is produced. 5. Method according to one of claims 1 to 4 characterized in that the article (1) is a cover. 6. Method according to claim 3 or 4 characterized in that the article (1) is a cover fitted with a straw (1d) forming a protuberance.