PACKAGING LID GRIPPING UNIT AND CLOSING MACHINE

Description

[0001] The invention relates to a packaging lid gripping unit with a gripper having a cavity formed around an axis and a wall encompassing the cavity, and with an ejector slidably guided along the axis, which comprises an inner part arranged at least partially within the cavity and an outer part arranged at least partially outside the wall and connected to the inner part by at least one connecting piece. The connecting piece extends through at least one recess formed in the wall.

[0002] A packaging lid gripping unit of this type is designed to grip a lid in an automated sealing process – which can also be combined with a filling process – in order to subsequently apply it to a packaging container, in particular a bottle. For this purpose, the gripper has a cavity in which a lid can be temporarily picked up and held.

[0003] In the sealing process, the lid is fed to the packaging container by the gripper. A linear and / or rotary motion, which is transferred to the lid by the gripper, then moves it onto an opening of the packaging container. Solutions are known in particular where the lid forms a screw closure with the packaging container, and the lid, held in the packaging lid gripping unit, can be screwed onto a container opening by a combined rotary and linear motion.

[0004] As with all industrial processes, there is always a risk of malfunction in an automatic capping operation. In particular, it can happen that a packaging container (bottle) intended for closure with the cap is not fed in, is not fed in correctly, or that the cap is incorrectly positioned within the gripper. As a result, a capping operation can fail, with the cap remaining stuck in the gripper. To ensure a defined, safe state of the capping machine, it is therefore known to equip the gripper with an ejector. This is automatically activated in the capping machine as soon as a successful capping operation should have been completed and the cap should have been removed from the gripper.If the lid unexpectedly remains in the gripper in this state, it is removed by the automatic ejector, so that the lid is ejected and a designated receiving position is freed up for the next lid.

[0005] Such a generic arrangement is known, for example, from EP 1 566 359 B1. The ejector has an inner part guided on the inside of the gripper and an outer ring for actuation, which are coupled to each other by a connecting bolt. The connecting bolt must be secured against falling out in a complex manner. Furthermore, for the ejector to be guided, it is necessary that it rests flat against the gripper. This design results in a high labor cost during assembly and maintenance and can only be adequately disinfected through extensive cleaning.

[0006] The invention is based on the objective of providing an improved packaging lid gripping unit which is easier to assemble and preferably can be cleaned and / or sterilized with minimal effort.

[0007] The subject matter of the invention and the solution to this problem is a packaging lid gripping unit according to claim 1 and a sealing machine equipped therewith according to claim 15. Preferred embodiments are specified in the dependent subclaims.

[0008] Based on the generic packaging lid gripping unit, the invention provides that the connecting piece is star-shaped with at least three arms, each of which extends through a recess in the wall. The at least three arms enable automatic centering of the inner part and / or the outer part. This can be used, in particular, to precisely position the inner part and / or the outer part with respect to the axis without having to provide a sliding guide.

[0009] In the context of the invention, the term "axis" refers to an imaginary geometric line with respect to which the packaging lid gripping unit is oriented. An axial direction denotes a directional extension along or parallel to the axis. The direction in which the gripper or the cavity within the gripper is accessible through a gripping opening for a packaging lid is to be understood as "down," while the opposite direction is also referred to as "up."

[0010] A direction perpendicular to the axis is called "radial," with a location closer to the axis being identified as "central" or "radially inward," and a location farther from the axis as "peripheral" or "radially outward." At positions outside the axis, a direction perpendicular to both the axial and radial directions is also called the direction of rotation or tangential direction.

[0011] Preferably, the number of recesses corresponds at least to the number of arms, and each recess is penetrated by exactly one assigned arm. This allows for a simple design, and the arms can be positioned to maintain a distance from the inner edge of the recesses.

[0012] The recesses are particularly preferably designed as elongated holes aligned parallel to the axis (axially). This provides space for movement in this axial direction.

[0013] Preferably, the outer part also has external elongated holes aligned parallel to the axis. This allows easy access to the gripper and the recesses formed therein for cleaning purposes. The external elongated holes are arranged in a circumferentially offset manner, preferably centrally between the recesses of the gripper.

[0014] The ejector is displaceable on the gripper, particularly in the axial direction, between an upper position and a lower position (ejection position). Preferably, the arms of the connecting piece have a distance from the gripper, in particular from an inner edge of the recess, in the lower position, the upper position, and all intermediate positions.

[0015] According to a preferred embodiment, the connecting piece has an odd number of arms, in particular exactly three arms. An odd number of arms contributes to additional stabilization and centering. A variant with exactly three arms also simplifies assembly. In this embodiment, the connecting piece is particularly Y-shaped, with each arm forming an angle of 120°. To position the connecting piece in the gripper, the Y-shaped connecting piece can be inserted through a recess in the wall, with the arms initially aligned in a plane passing through the axis. In this position, two arms can be inserted into the cavity through a recess.Then, as the Y-shaped intermediate piece is further inserted, it is rotated around the longitudinal extension direction of the third arm, which is perpendicular to the axis, thereby rotating the plane of the arms perpendicular to the axis and causing the two previously inserted arms to engage in their respective recesses and exit the gripper through these recesses.

[0016] It is particularly preferred that the inner part is connected to at least three arms, in particular exactly three arms, of the connecting piece and / or that the outer part is connected to at least three arms, in particular exactly three arms, of the connecting piece. The connection at three points ensures that the positioning and centering are mechanically unambiguous – even if the connection between the inner part or the outer part and the connecting piece is longitudinally displaceable, particularly along a longitudinal direction of the arms.

[0017] Preferably, the arms have a round cross-section. An arm with a round cross-section has the advantage that it has no edges that could complicate cleaning or damage other components. The rounded shape also facilitates easy spray treatment, for example, for disinfection or sterilization.

[0018] According to a particularly preferred embodiment, the arms have a continuous circular cross-section extending from a central area, especially perpendicular to a longitudinal direction of the respective arm. The radius of the cross-section can vary along the length of the arm, but is preferably essentially constant. In particular, the arm has a constant cross-section over at least 90% of its length and is only chamfered and / or rounded at its end furthest from the central area. Such a uniform circular cross-section allows, in the case of a positive-locking connection, such as a snap-fit ​​connection, not only rotational compensation around the arm, but also longitudinal displacement in the longitudinal direction of the arm.

[0019] According to a preferred embodiment of the invention, the outer part, the inner part, and / or the wall are tubular in shape. Tubular in shape means, in particular, that the respective part has a base body which extends rotationally symmetrically around an axis of symmetry from an inner radius to an outer radius. The difference between the inner and outer radii is also referred to as the thickness or tube thickness. The surface of the base body is formed section by section by an inner and outer cylindrical surface around the axis of symmetry. Particularly preferably, the axis of symmetry of a tubular inner part, outer part, and / or wall coincides with the axis of the packaging lid gripping unit. They are thus concentric around the axis.

[0020] According to a particularly preferred embodiment, the connecting piece is connected to the inner part and / or the outer part by at least one snap-fit ​​connection. A snap-fit ​​connection is understood to be a form-fit, force-fit, and / or friction-fit connection that can be created by applying force. For example, a first connecting partner and a second connecting partner can be forced together, whereby one or more locking elements arranged on the first connecting partner and / or the second connecting partner are displaced and / or deformed by the force. After the adjusting partners have reached a predetermined fixed position relative to each other, the locking elements return to a locked position through a return movement, in which a change of position is prevented or at least made more difficult.

[0021] According to a particularly preferred embodiment, the locking device formed on the inner or outer part comprises at least one spring arm, which has an inner surface adapted to the outer shape of the arm. When the intermediate piece is inserted into a corresponding receptacle, the spring arm is bent apart from the inner surface to allow insertion of the arm. In the intended locking position, the spring arm returns to its original position, in which its inner surface rests against an outer surface of the arm.

[0022] Preferably, the locking connection is formed by a locking device formed on the inner part or on the outer part, which is in contact with an outer surface of the arm, in particular lying flat against it.

[0023] According to a particularly preferred embodiment of the invention, each of the arms is connected to the inner part and / or the outer part by a snap-fit ​​connection. Because the inner part and / or the outer part are connected to each of the at least three arms, an automatic centering effect is achieved. If both the inner part and the outer part form such a snap-fit ​​connection with all arms at least three times, absolute centering—i.e., centering of the inner part and the outer part relative to each other—is effected.

[0024] Preferably, the locking device is formed in one piece – i.e., from a single piece of material and without interruption – together with its respective inner and outer parts. The locking element of the locking connection is therefore formed by a portion of the inner or outer part, in particular at least one formed spring arm. This enables particularly simple manufacturing. For example, the locking device can either be cut / milled from a solid blank or manufactured using other forming processes such as injection molding or additive manufacturing techniques.

[0025] According to a particularly preferred embodiment, the inner part, the outer part, and / or the connecting piece are made of a plastic material, especially as an injection-molded part. Plastics, particularly injection molding, allow for the cost-effective production of molded parts in large quantities. Depending on the chosen plastic material (polymer composition and additives), these parts exhibit high mechanical stability and durability as well as high chemical resistance. They are therefore suitable for use in automatic filling machines and also for automatic sterilization.

[0026] According to a preferred embodiment, the wall is formed with an inner surface (in particular, rotationally symmetrical about the axis), and the inner part is arranged – in all operating states – with a (minimum) distance of at least 1 mm, preferably at least 2 mm, inside the gripper. Through this gap of at least 1 mm or at least 2 mm, it is possible, during automatic disinfection or sterilization, to reliably and effectively distribute a chemical disinfectant between the inner surface and the inner part, thus ensuring sterility. In the case of a tubular inner part, the minimum distance between the inner part and the inner surface of the wall is at least once, preferably at least twice, and in particular at least three times the thickness of the inner part.

[0027] According to a preferred embodiment, it is alternatively or additionally provided that the wall is formed with an outer surface (in particular, rotationally symmetrical about the axis) and that the outer part has a base body that completely surrounds the gripper and has a (minimum) distance of at least 1 mm, preferably at least 2 mm, from the outer surface. The base body is particularly tubular, wherein the minimum distance to the outer surface of the gripper corresponds to at least once, preferably at least twice, and in particular at least three times the thickness of the tubular base body. This ensures penetration between the outer part and the gripper.

[0028] According to a preferred embodiment, the outer part has at least three inwardly projecting contact projections – particularly extending from a tubular base body – which are guided on an outer surface of the gripper. This ensures the concentric guidance of the outer part – and thus, indirectly, also of the inner part – on the gripper. It also allows the minimum distance between the base body and the outer surface of the gripper to be adjusted.

[0029] Preferably, the outer part has at least three radially inwardly projecting guide projections – particularly extending from a tubular base body – which engage in corresponding guides of the gripper and are, in particular, linearly guided in the axial direction by these guides. This enables the outer part or the entire ejector to be secured against rotation.

[0030] To grip a packaging lid, particularly a bottle screw cap, the gripper preferably has at least one movable gripping element projecting inwards from the wall. This is also referred to as a pin. A packaging lid held in the gripper rests against this at least one gripping element. Typically, a plurality of gripping elements are arranged around the circumference of the gripper – preferably at the same circular spacing. This ensures that the packaging lid is held solely by contact with the gripping elements. The gripping elements can be replaced when worn. The gripping elements are particularly preferably pre-tensioned inwards, i.e., subjected to force, in particular by a spring ring. When a packaging lid is inserted, the gripping elements are displaced outwards against the spring tension of the spring ring and hold the lid in place during the packaging process by frictional engagement.

[0031] According to a particularly preferred embodiment, the gripper has at least one gripping head forming the wall and a support connected to the gripping head. The gripping head is also commonly referred to as a "cone". The support is preferably designed as a tube rotationally symmetrical about the axis and screwed to the gripping head. A seal, in particular an aseptic O-ring seal, is preferably arranged at the joint between the gripping head and the support, which preferably forms a circumferential groove. To prevent wear, the gripping head and / or the support are made of stainless steel, in particular hardened stainless steel.

[0032] The invention also relates to a sealing machine equipped with a previously described packaging lid gripping unit. The packaging lid gripping unit is preferably rotatable about the axis and / or longitudinally displaceable along the axis on the sealing machine.

[0033] An embodiment of the invention is explained below with reference to the figures. These schematically show: Fig. 1 a perspective view of a packaging lid gripping unit according to the invention, Fig. 2 a perspective view of the gripper of the packaging lid gripping unit made of Fig. 1 , Fig. 2 Legs perspective view of the ejector of the packaging lid gripping unit made of Fig. 1 , Fig. 3 an exploded view of the ejector made of Fig. 2B and Fig. 4 an alternative perspective to Fig. 2B .

[0034] The Fig. 1 Figure 1 shows a perspective view of a packaging lid gripping unit 1 according to the invention. This unit comprises, as shown in the figures below, a packaging lid gripping unit 1 according to the invention. Fig. 2A und 2B The figure shows a gripper 2 and an ejector 3 arranged on the gripper 2. In the illustrated embodiment, the gripper 2 comprises a gripping head 2a and a tubular support 2b screwed to the gripping head 2a. An O-ring seal 2c is arranged at the interface between the support 2b and the gripping head 2a. The gripper 2 also has a cavity 4 formed in the gripping head 2a around an axis A, which is accessible through a gripping opening 2d on the underside of the gripping head 2.

[0035] The gripping head 2a forms a wall 5 encompassing the cavity 4 concentrically around the axis A, in which recesses 5a are formed that penetrate the wall 5 from the radially inner cavity 4 to the outside. The recesses 5a are each bounded by edges 5b and are designed as elongated holes oriented in the axial direction x – i.e., parallel to the axis A. Gripping elements 6 are arranged circumferentially around the lower edge of the gripping head 2a, which penetrate the wall 5 radially inwards and are subjected to inwards force by an external spring ring 7.

[0036] In the Fig. 2B The ejector 3 is shown separately. It has an inner part 8 which, in the assembled state, is located entirely within the cavity 4 of the gripper head 2a. Furthermore, the ejector 3 comprises an outer part 9 that surrounds the gripper 2 on the outside. The inner part 8 and the outer part 9 are connected to each other via a connecting piece 10, the connecting piece 10 passing through recesses 5a in the wall 5. The individual components of the ejector 3 are shown in the Fig. 3 shown again separately. It can be seen that the connecting piece 10 is star-shaped according to the invention, with three arms 10a, each of which extends through an associated recess 5a. In the exemplary embodiment, exactly three arms 10a are provided. The number of recesses 5a in the wall 5 is greater, namely twice as many, with six recesses 5a.

[0037] How to particularly the Fig. 2B As can be seen, both the inner part 8 and the outer part 9 are connected to each of the three arms 10a of the connecting piece 10 by snap-fit ​​connections 11. For this purpose, outer spring arms 9a are formed on the outer part 9 and inner spring arms 8a are formed on the inner part, which, in the connected state, encompass the arms 10a and bear against their outer surfaces, which are rotationally symmetrical about the longitudinal axes I.

[0038] How to particularly understand the exploded view of the Fig. 3 and the detailed view of the Fig. 4 As can be seen, both the inner part 8 and the outer part 9 are tubular around axis A. The inner part 8 is entirely tubular and consists solely of a base body extending between a first inner radius r1 and a first outer radius R1. The difference between these radii forms the first tube thickness d1. In addition to the openings provided for the snap connections 11, the inner part 8 has additional recesses 8b for cleaning purposes.

[0039] The outer part 9 has a tubular base body 9b enclosing the wall 5, which extends from the axis A from a second inner diameter r 2 to a second outer radius R 2. In the illustrated embodiment, the second tube thickness d 2, which is formed as the difference between the two, is identical to the first tube thickness d 1.

[0040] To actuate the ejector 3 in a capping machine, an outwardly projecting actuating rim 9c is formed at the upper edge of the encompassing base body 9b. This provides an (enlarged) contact surface for actuating tools with which the ejector 3 can be moved downwards to remove a lid held in the gripper head 2a.

[0041] Cleaning windows 9d are formed in the tubular base body 9b, which, in the assembled state, are arranged alternately in the circumferential direction with the recesses 5a in the wall 5 of the gripper 2. This allows for particularly good penetration with a cleaning fluid during sterilization.

[0042] On the inside of the base body 9b, contact projections 9e are formed, which bear against an outside surface of the gripper 2, in the exemplary embodiment against an outer surface of the support tube 2b, and are thereby guided longitudinally displaceable in the axial direction x. In the illustrated variant, the contact projections 9e are arranged in three pairs offset by 120° around the circumference. The contact projections are positioned centrally between the arms 10a of the connecting piece 10.

[0043] Furthermore, guide projections 9f extend from the inner side of the base body 9b, which are linearly guided in corresponding recesses 5a in the wall 5. This provides not only axial guidance but also anti-rotation protection. The guide projections 9f are also arranged in pairs offset by 120° around the circumference of the base body 9b and are axially aligned with the contact projections 9e. For assembly, the corresponding recesses 5a in the wall 5 are designed with insertion openings 5c. At least over a limited depth range, these recesses 5a are designed as elongated slots open on one side, which allow axial insertion of the outer part 9.

[0044] The ejector 3 is attached to the gripper 2 between one in the Fig. 1The lower ejection position and an upper position are axially displaceable. It can be seen that both the inner part 8 maintains a minimum first distance a 1 and the base body 9b of the outer part 9 maintains a minimum second distance a 2 to the wall 5 of the gripper 2. Likewise, the arms 10a of the connecting piece 10 have a minimum third distance a 3 to the edge 5b of the recesses 5a.

[0045] The minimum distances a1, a2, a3 of at least 2 mm ensure reliable penetration of the cleaning agent. These minimum distances a1, a2, a3 are also larger than the pipe thicknesses d1, d2. Furthermore, the wall 5 has an inner surface 5b which is at least 2 mm further from the axis than the outer radius R1 of the inner part 8. Similarly, an outer surface 5e of the wall 5 is arranged at a distance from the axis A that is at least 2 mm smaller than the inner radius r2 of the tubular base 9b of the outer part 9.

Claims

1. Package lid gripping unit (1) with a gripper (2) which has a cavity space (4) formed about an axis (A) and a wall (5) surrounding the cavity space (4), and with an ejector (3) that is guided displaceably along the axis (A), comprising an inner part (8) arranged inside the cavity space (4) and an outer part (9) arranged outside the wall (5) and connected to the inner part (8) by at least one connecting piece (10), wherein the connecting piece (10) passes through at least one opening (5a) formed in the wall (5), characterised in that the connecting piece (10) is star-shaped with at least three arms (10a), each of which passes through an opening (5a) in the wall (5).

2. Package lid gripping unit (1) according to claim 1, characterised in that the number of openings (5a) is at least equal to the number of arms (10a), and each opening (5a) is passed through by no more than exactly one associated arm (10a).

3. Package lid gripping unit (1) according to claim 1 or 2, characterised in that the connecting piece (10) has an odd number of arms (10a).

4. Package lid gripping unit (1) according to any of the preceding claims, characterised in that the inner part (8) is connected to at least three arms (10a) of the connecting piece (10) and / or the outer part (3) is connected to at least three arms (10a) of the connecting piece (10).

5. Package lid gripping unit (1) according to any of the preceding claims, characterised in that the arms (10a) have a round cross-section.

6. Package lid gripping unit (1) according to any of the preceding claims, characterised in that the wall (5), the outer part (9) and / or the inner part (8) are tubular.

7. Package lid gripping unit (1) according to any of the preceding claims, characterised in that the connecting piece (10) is connected to the inner part (8) and / or the outer part (9) by at least one latching connection (11).

8. Package lid gripping unit (1) according to claim 7, characterised in that the latching connection (11) is formed by a latching device formed on the inner part (8) and / or the outer part (9), which is in contact with an outer surface of an arm (10a).

9. Package lid gripping unit according to claim 8, characterised in that the latching device comprises at least one spring arm (8a, 9a) which has an inner surface adapted to the outer shape of the arm (10a).

10. Package lid gripping unit (1) according to claim 8 or 9, characterised in that the latching device is formed in one piece with the inner part (8) and / or the outer part (9).

11. Package lid gripping unit (1) according to any of claims 7 to 10, characterised in that each of the arms (10a) is connected to the inner part (8) and / or the outer part (9) by a latching connection (11).

12. Package lid gripping unit (1) according to any of the preceding claims, characterised in that the inner part (8), the outer part (9) and / or the connecting piece (10) are each formed in one piece.

13. Package lid gripping unit (1) according to any of the preceding claims, characterised in that the inner part (8), the outer part (9) and / or the connecting piece (10) are made of a plastic material, in particular as an injection-moulded part.

14. Package lid gripping unit according to any of the preceding claims, characterised in that the wall (5) is formed with an inner surface (5d) and that the inner part (8) is arranged with a minimum first spacing (a1) of at least 1 mm, preferably at least 2 mm, inside the gripper (2), and / or that the wall (5) is formed with an outer surface (5e) and that the outer part (9) is arranged with a minimum second spacing (a2) of at least 1 mm, preferably at least 2 mm, outside the gripper (2).

15. Capping machine, in particular bottle capper, characterised in that the packaging machine has at least one package lid gripping unit (1) according to any of the preceding claims.