Picking up and closing unit for soft plastic caps, particularly for straight chamber capping machines

Description

[0001] The present invention refers to a picking up and closing unit for soft, i.e. bendable, plastic caps, particularly for straight chamber capping machines.

[0002] A straight chamber capping machine is known from US-A-3 137 982, in which the containers to be closed are supplied in a continuous way, resting on a conveyor belt and pressed between two guide means parallel to the converyor belt at a certain distance from it, till a position in which each of the containers hooks with its upper edge the lower edge of a cap which leans out of a suitable feed guide, entraining the cap with it at first under a picking up roller, then under a pressure roller and at last under a finishing roller in order to complete the automatic closing operation.

[0003] US-A-4 122 649 describes a positioning and placement device for the application of square covers to square containers. Such a device particularly includes a three roller positioning and registration means for locating the covers with respect to the containers.

[0004] The main drawback with the known capping machines is that the closing operation gives rise to the compression of a certain amount of air inside the container or can. As a consequence of this, it can occur that the caps lift up again, in a more or less short time, till causing sometimes the unsuccessful tight seal between the cap and the container, with a consequent waste of the product contained in the container, due to leak or contamination. As this drawback cannot obviously be accepted, a manual final revision is generally requested by workers taken on on purpose, which leads to a noticeable rise in the production costs.

[0005] Therefore, the main object of the present invention is to improve the capping machines for soft plastic caps, by providing a picking up and closing unit provided with means for helping the air to escape from the container.

[0006] The picking up and closing unit for soft plastic caps, particularly for straight chamber capping machines, according to the present invention is characterized in that the pressure roller has a narrow crosswise dimension with respect to the cap diameter and a lower tab extends from the feed guide towards the pressure roller, the arrangement being such that, when the cap is going out of the feed guide, under the action of a suitable spring, the pressure roller exercises a force concentrated on the centre of the cap and at the same time the lower tab keeps the back edge of the cap lifted up, so as to make the air escape from the container easier.

[0007] In the following, the present invention will be further clarified from the description of one form of practical embodiment of the picking up and closing unit for soft plastic caps, particularly for straight chamber capping machines, description made in a purely illustrative and not limitative way, with reference to the accompanying drawings, in which;

Figure 1 is a plan view of the unit of the present invention;

Figure 2 is a lateral section view taken on the line II-II of Figure 1; and

Figures 3 to 5 are lateral views of the present unit and show the cap and the can in some significant positions during the closing operation.

[0008] With reference to the accompanying drawings, and in particular to the Figures 1 and 2 thereof, it is seen that the present picking up and closing unit for soft plastics caps, particularly for straight chamber capping machines, comprises a feed guide 10 for the caps 12 that must be applied on containers or cans 14 which proceed on a suitable conveyor belt of the endless type (not shown).

[0009] As it is usual in the straight chamber machines, the containers or cans 14 proceed in a continuous way and at a uniform speed, gathered together in any way, on a conveyor belt, laterally guided by two belts that proceed parallel to the conveyor belt at a certain height from it and press the cans on their sides, forcing them to proceed without overturning.

[0010] The feed guide 10 for the caps comprises two lateral C shaped rails 16, 18, inside which the caps 12 slide. The two lateral rails 16 and 18 end in two lateral spring stop 20 and 22, respectively, whereas the upper part of the guide 10 ends in an upper guide tab 24 and the lower part of the guide 10 itself ends in a lower guide tab 26.

[0011] A front picking up roller 28 is located immediately downstream the output of the feed guide 10 and has a groove 30 in which a wheel or central pressure roller 32 goes in, loaded by a spring 34 downwards, as seen in Figure 2, in the direction that tends to compress the cap on the underlying can.

[0012] A back finishing roller 36 is located downstream the central roller 32 and is spring loaded downwards, as seen in Figure 2, by a spring 38.

[0013] The front roller 28 is spring loaded downwards, always as seen in Figure 2, by a spring 40 and both the rollers 28 and 36 are hinged to the frame 42 of the picking up unit around a hinge shaft 44, by means of suitable bearings 46 and 48.

[0014] The central pressure roller 32 is hinged around a hinge shaft 50 by means of a suitable bearing 52.

[0015] Further structural details of the picking up and closing unit will be pointed out in the following, during the explanation of the operation of the unit, with reference to the Figures 3, 4 and 5.

[0016] Each cap 12, under the push of its own weight and that of the caps which follow it, in its turn, locates itself at the stroke end in the feed guide 10, resting against the spring stops 20 and 22, as shown in Figure 3. In this position, the cap 12 is kept centered in the crosswise direction with respect to the motion direction by the guides 16 and 18 and in the vertical direction by the upper guide tab 24 and the lower guide tab 26. Therefore the waiting position, in which the cap 12 waits for being engaged by the can, is unambiguous and well determined.

[0017] When a can or glass 14, advancing entrained by the conveyor belt and lateral belts, reaches the position shown in Figure 3, it touches the front edge of the cap and penetrates inside it, securing the entrainment of the cap. In other words, the flat surface of the cap 12 exhibits a certain angle with respect to the glass 14, resting on the lower tap 26, but its front edge goes down till under the edge of the glass 14 and thus is hooked by it.

[0018] From this moment, the can 14, advancing, entrains the cap with it, at first under the front roller 28, which acts as an extension of the feed guide 10, accompanying the cap in its advancing, and then under the central pressure roller 32, till the position shown in Figure 4.

[0019] In this position, it is pointed out that the central roller, being much narrower than the cap under the action of its spring 34, exercises a force concentrated on the centre of the cap 12, and this serves to secure the way out of the air, while at the same time the lower tab 26 keeps lifted up the back edge of the cap 12 itself, in order to always provide a way out for the air, which otherwise would remain trapped inside the can and could subsequently cause the re-opening of the can, due to the lifting pf the cap.

[0020] By further proceeding in its movement, the glass 14 arrives under the back roller 36, as better shown in Figure 5. The function of the back roller 36 is to secure the stability of the can 14, in the moment in which the central roller 32 presses with all the force of the spring 34 on the back edge of the can 14. Furthermore, the back roller 36 serves for finishing the closing of the glass 14, since it presses on the surface of the cap all along the edge of the can 14.

[0021] Therefore, when the central pressure roller 32 leaves the cap, inside the closed container a certain depression remains, which helps the maintaining of the closure.

[0022] It is to be noted that, in the regular operation, the front roller 28 is at its stroke end downwards and from this position it is moved only in the case in which there are cans ill-positioned on the conveyor belt or out of tolerance, whereas the back finishing roller 36 carries out a little upwards movement equal to the tolerances in height among the various glasses, i.e. in other words, the front picking up roller 28 is designed yielding against the action of the spring 40, only for safety's sake.

[0023] Furthermore, it is to be noted that the rotation centres of the bearings of the three rollers are so located that the lifting path of the central roller 32 has a component directed in the direction of advancing of the can, and this helps the lifting of the roller 32 by the can, whereas the lifting paths of the front roller 28 and back roller 36 have a component directed in the direction opposite to the advancing of the can, and this in order to carry out the last attempt to correctly relocate the can in case of fortuitous bad positioning.

[0024] In such a manner, the fulcrum system of the various rollers, takes the maximum advantage of the load of the springs, without stressing the bearings, which assure anyway the necessary stiffness.

[0025] Obviously, instead of using hinged bearings, means can be used, which allow a vertical straight movement of the various rollers, under the above described forces, such as for example stud bolts with antifriction guides.

Claims

1. A picking up and closing unit for soft plastic caps (12), particularly for straight chamber capping machines, in which the containers (14) to be closed are supplied in a continuous way, resting on a converyor belt and pressed between two belts which proceed parallel to the conveyor belt at a certain distance from it, until a position in which each of them hooks with its upper edge the lower edge of a cap which leans out of a suitable feed guide (10), entraining the cap with it at first under a picking up roller (28), then under a pressure roller (32) and at last, under a finishing roller (36), characterized in that said pressure roller (32) has a narrow crosswise dimension with respect to the cap diameter; and a lower tab (26) extends from said feed guide (10) towards said pressure roller (32), the arrangement being such that, when the cap is going out of the feed guide (10), under the action of a suitable spring (34), said pressure roller (32) exercises a force concentrated on the center of the cap (12) and at the same time said lower tab (26) keeps the back edge of the cap (12) lifted up, so as to make the air escape from the container easier.

2. A unit according to claim 1, characterized in that said feed guide (10) comprises an upper guide tab (24), which is located centrally with respect to the feed guide (10) and cooperates with the lateral rails (16, 18) of the feed guide (10) to keep the cap centered in its waiting position.

3. A unit according to claim 1 or 2, characterized in that said picking up roller (28) is located immediately downstream from the output of the feed guide (10) in a raised position with respect to said pressure roller (32), the arrangement being such that said picking up roller (28) acts as an extension of said feed guide (10), accompanying the cap in its advancing. _:

4. A unit according to any one of the preceding claims, characterized in that said pressure roller (32) is installed on a bearing hinged to the unit frame upstream from said pressure roller (32), the arrangement being such that the lifting path thereof has a component directed in the advancing direction of the container to be closed.

5. A unit according to any one of the preceding claims, characterized in that said picking up roller (28) is installed on a bearing hinged to the unit frame downstream from said picking up roller (28), the arrangement being such that the lifting path thereof has a component directed in the opposite direction with respect to the advancing direction of the container to be closed.

6. A unit according to any one of the preceding claims, characterized in that said finishing roller (36) is installed on a bearing hinged to the unit frame downstream from said finishing roller (36), the arrangement being such that the lifting path thereof has a component directed in the opposite direction with respect to the advancing direction of the container to be closed.

7. A unit according to any one of the claims 1 to 3, characterized in that said pressure roller (32) is installed on stud bolts with antifriction guides.

8. A unit according to any one of the claims 1 to 3, characterized in that said picking up roller (28) is installed on stud bolts with antifriction guides.

9. A unit according to any one of the claims 1 to 3, characterized in that said finishing roller (36) is installed on stud bolts with antifriction guides.

Ansprüche

1. Vorrichtung zum Zuführung Anbringen von weichen Kunststoffkapseln (12), insebesondere für geradlinigen Verschliessmaschinen, wobei die zu verschliessende, auf einem Förderband aufliegende Behälter (14) fortdauerned zugeführt und zwischen zwei Bänder zusammengedrückt werden die dem Förderband mit einem gewissen Abstand parallel laufen bis zu einer Lage in der en jeder Band mit seinem oberen Rand das untere Rand einer aus einer geeigneten Fürhungsbahn (10) herausragenden Kapsel derart einhackt dass er die Kapsel zuerst unter einer Zuführungsrolle (28), dann unter einer Druckrolle (32) und schliesslich unter einer Fertigungsrolle (36) mitrisst, dadurch gekennzeichnet dass die Druckrolle (32) eine engere Querabmessung in Bezug auf dem Durchmesser der Kapsel aufweist; und eine untere Zunge (26) sich von der Führungsbahn (10) in die Richtung der Druckrolle (32) erstreckt, wobei sobald die Kapsel sich von der Führungsbahn (10) entfernt die Druckrolle (32), unter dem Einfluss einer geeigneter Feder (34), eine Kraft ausübt die auf die Mitte der Kapsel (12) konzentriert ist, während die untere Zunge (26) den hinteren Rand der Kapsel (12) zugleich aufgehoben hält, sodass die Entlüftung des Behälters erleichtert wird.

2. Vorrichtung gemäss Anspruch 1, dadurch gekennzeichnet dass die Führungsbahn (10) aus einer oberen Führungszunge (24) besteht die mittig in Bezug auf die Zuführungsbahn (10) liegt und mit den seitlichen Balken (16, 18) der Führungsbahn (10) zusammenarbeitet um die Kapsel in ihre Wartungsstelle zentriert zu halten.

3. Vorrichtung gemäss Ansprüchen 1 oder 2, dadurch gekennzeichnet dass die Zuführungsrolle (28) stromabwärts in Bezug auf die Führungsbahn (10) liegt, in einer erhebenen Stelle in Bezug auf die Druckrolle (32), wobei die Zuführungsrolle (28) als eine Verlängerung der Führungsbahn (10) wirkt um die Kapsel während ihres Verschluss zubegleiten.

4. Vorrichtung gemäss irgendeiner dervvorstehenden Ansprüchen, dadurch gekennzeichnet dass die Druckrolle (32) auf einem auf dem Rahmen der Vorrichtung stromabwärts von der Druckrolle (32) abklappbar ist, wobei ihre Erhebungsbahn eine Kompnent aufweist in der Vorschubrichtung des zu verschliessenden Behälters.

5. Vorrichtung gemäss irgendeiner der vorstehenden Ansprüchen, dadurch gekennzeichnet dass die Zuführungsrolle (28) auf einem auf dem Rahmen der Vorrichtung stromabwärts von den Zuführungsrolle (28) aufklappbaren Lager aufgestellt ist, wobei ihre Erhebungsbahn einen in der entgegengesetzten Richtung in Bezug auf den Vorschub des zu verschliessenden Behälters aufweist.

6. Vorrichtung gemäss irgendeiner der vorstehenden Ansprüchen, dadurch gekennzeichnet dass die Fertigungsrolle (36) auf einem auf den Rahmen der Vorrichtung stromabwärts von der Fertigungsrolle (36) aufklappbaren Lager montiert ist, wobei ihre Erhebungsbahn einen in der entgegengesetzten Richtung in Bezug auf den Vorschub des zu verschliessenden Behälter aufweist.

7. Vorrichtung gemäss irgendeiner der Ansprüchen 1-3, dadurch gekennzeichnet dass die Druckrolle (32) auf mit antifriktion Führungsbahnen ausgestattenen Stiftschrauben gestellt ist.

8. Vorrichtung gemäss irgendeiner der Ansprüchen 1-3, dadurch gekennzeichnet dass die Zuführungsrolle (28) auf mit antifriktion Führungsbahnen ausgestattenen Stiftschrauben gestellt ist.

9. Vorrichtung gemäss irgendeiner der Ansprüchen 1-3, dadurch gekennzeichnet dass die Fertigungsrolle (36) auf mit antifriktion Führungsbahnen ausgestattenen Stiftschrauben gestellt ist.

Revendications

1. Dispositif d'alimentation et de fermeture pour capsules synthétiques molles (12), particulièrement pour machines de fermeture rectilignes, dans lequel les récipients (14) à fermer sont fournies de façon continue, étant posés sur une bande transporteuse et comprimés entre deux bandes qui procèdent parallèlement à la bande transporteuse à une certaine distance de cette dernière, jusqu'à une position dans laquelle chacun accroche par son bord supérieur le bord inférieur d'une capsule saillante à partir d'un coulisseau approprié (10), entrainant la capsule d'abord sous un rouleau d'alimentation (28), ensuite sous un rouleau presseur (32) et enfin sous un rouleau finisseur (36), caractérisé par le fait que le rouleau presseur (32) a une dimension transversale étroite par rapport au diamètre de la capsule; et une languette inférieure (26) s'étend du coulisseau (10) vers le rouleau presseur (32), la disposition étant telle que, lorsque la capsule sort du coulisseau (10), sous l'action d'un ressort adapté (34), le rouleau presseur (32) exerce une force concentrée sur le centre de la capsule (12) et au même temps la languette inférieure (26) maintient le bord postérieure de la capsule (12) soulevé, de façon a faciliter la sortie de l'air du récipient.

2. Dispositif selon la revendication 1, caractérisé par le fait que le coulisseau (10) comprend une languette de guidage supérieure (24) qui est située centralement par rapport au coulisseau (10) et qui coopère avec le fers latéraux (16,18) du coulisseau per maintenir la capsule centrée dans sa position d'attente.

3. Dispositif selon les revendications 1 ou 2, caractérisé par le fait que le rouleau d'alimentation (28) è situé immédiatemente en aval de la sortie du coulisseau (10) dans une position soulevée par rapport au rouleau presseur (32), la disposition étant telle que les rouleau d'alimentation (28) fonctionne comme un prolongement du coulisseau (10), accompagnant la capsule dans son avancement.

4. Dispositif selon l'une ou l'autre des revendications précédentes, caractérisé per le fait que le rouleau presseur (32) est installé sur un palier monté au moyen de charnières sur le chassis du dispositif en amont du rouleau presseur (32), la disposition étant telle que son parcours de soqlè- vement a une composante orientée dans la direction d'avancement du récipient à fermer.

5. Dispositif selon l'une ou l'autre des revendications précédentes, caractérisé par le fait qu le rouleau d'alimentation (28) est installé sur un palier monté au moyen de charnières sur le chassis du dispositif en aval du rouleau d'alimentation (28), la disposition étant telle que son parcours de soulèvement a une componsante orientée dans la direction opposée par rapport à la direction d'avancement du récipient à fermer.

6. Dispositif selon l'une ou l'autre des revendications précédentes, caractérisé par le fait que le rouleau finisseur (36) est installé sur un palier monté au moyen de charnières sur le chassis du dispositif en aval du rouleau finisseur (36), la disposition étant telle que son parcours de soulèvement a une composante orientée dans la direction opposée par rapport à la direction d'avancement du récipient à fermer.

7. Dispositif selon l'une ou l'autre des revendications 1-3, caractérisé par le fait que le rouleau presseur (32) est installé sur des goujons avec des guides antifriction.

8. Dispositif selon l'une ou l'autre des revendications 1-3, caractérisé par le fait que le rouleau d'alimentation (28) est installé sur des goujouns avec des guides antifriction.

9. Dispositif selon l'une ou l'autre des revendications 1-3, caractérisé par le fait que le rouleau finisseur (36) est installé sur des goujons avec deu guides antifriction.

Drawing