EP0139977A2 - Closing head for pressing a cap on a container neck - Google Patents

Abstract

A sealing head having a pressure plate for pressing a sealing cap onto a container neck in which the pressure plate has a curved rolling surface via which the pressure plate lies on a curved bearing surface which is opposite the rolling surface, and at least one spring which presses the pressure plate against the rolling surface is arranged between the sealing head and the pressure plate. In a preferred embodiment, the bearing surface is concave and the rolling surface is convex, the curvature of the bearing surface being at most as great as the curvature of the rolling surface. The curvature of the rolling surface may be spherical, with the centre of curvature coinciding with the centre of the pressure surface of the pressure plate. <IMAGE>

Description

The invention relates to a closing head with a pressure plate for pressing a closure cap onto a container neck.

Such a capping head is sometimes referred to as a plunger. Such closure heads are used in particular in so-called bottle closure machines. The sealing head carries a sealing cap on the container neck to be sealed. If the closure cap is made of metal, it is then usually rolled onto a thread on the neck of the container. For this purpose, the sealing head must press the sealing cap onto the container neck with sufficient pressure so that the sealing cap is stuck during the rolling process. For this purpose, the sealing head has a pressure plate on its end face which is adapted to the contour of the sealing cap.

However, it cannot always be avoided that the container neck or the container as a whole is tilted with respect to the alignment of the pressure plate of the closing head. This cannot be entirely ruled out due to slight tolerances of the sealing machine, which are always present in mechanical devices of this type. It cannot be ruled out that a container or a container neck is slightly deformed, so that as a result it is also tilted with respect to the closing head with the pressure plate.

Previous sealing heads are rigidly aligned with their pressure plate, so they can only be moved in height to press the sealing cap onto the container neck. According to the prior art, tilting cannot be followed or given.

The invention has for its object to provide a capping head of the type mentioned, which is able to yield or follow tilts.

This object is achieved in that the pressure plate has a curved rolling surface with which the pressure plate rests on a bearing surface curved opposite the rolling surface and that at least one spring is arranged between the capping head and the pressure plate, which presses the pressure plate against the rolling surface. The pressure plate can therefore roll with its rolling surface on the bearing surface on the capping head and thus assume practically any tilt positions relative to the capping head. The spring between the closing head and the pressure plate always holds the pressure plate with its rolling surface against the bearing surface, so that the pressure plate in particular does not fall off the bearing surface. This would in fact leave an adverse impact path between the pressure plate and the closing head, as a result of which the pressure plate, when it is quickly and mechanically placed on the closure cap on the Would hit the neck of the container with force against the bearing surface on the closing head. In addition, the at least one spring has the task of returning the pressure plate in its free position to the untilted position aligned with the closing head.

It is preferred that the bearing surface is concave, ie curved inwards, and the rolling surface is convex, ie curved outwards, the curvature of the bearing surface being at most as large as the curvature of the rolling surface.

It is particularly advantageous that at least the curvature of the rolling surface is spherical and the center of curvature coincides with the center of the printing surface of the printing plate. In such a case it is ensured that the pressure force of the sealing head always acts centrally on the pressure surface and thus on the sealing cap on the container neck, so that the sealing cap is pressed evenly over the entire circumference onto the container neck.

According to a special embodiment, the curvature of the bearing surface is smaller than the curvature of the rolling surface and the at least one spring between the closing head and the pressure plate is arranged in the center of the bearing surface and the pressure plate.

• Figur 1 eine Ausführungsform mit einer zentralen Feder;
• Figur 2 eine Ausführungsform mit mehreren Federn über dem Umfang der Druckplatte zwischen derselben und dem Verschließkopf.

Two embodiments of the invention are shown in the drawings. In it show:

• Figure 1 shows an embodiment with a central spring;
• Figure 2 shows an embodiment with several springs over the circumference of the pressure plate between the same and the closing head.

FIG. 1 shows the cross section through a closing head according to the invention. The arrangement has essentially rotational symmetry. On the front side of the closing head 1, a concavely curved, that is to say inwardly curved bearing surface 5 is provided. The rolling surface 6 of the pressure plate 7 lies on this bearing surface. The pressure plate 7 presses with its pressure surface 11 the closure cap 9 onto the container neck, not shown, of a container, also not shown. The rolling surface 6 is spherical, that is, spherically curved. The curvature is chosen so that the center of curvature lies in the center of the pressure surface 11. This is indicated in the figure by the radius of curvature r shown. In the center of the rolling surface 6 and the bearing surface 5 there is a spring 4 between the closing head 1 and the pressure plate 7. This spring presses or pulls the pressure plate 7 with its rolling surface 6 against the bearing surface 5 on the closing head 1. There is between the closing head 1 and the pressure plate 7, a circumferential O-ring 12 is provided in a circumferential groove 13 in the end face of the closing head 1. This 0-ring 12 causes an additional, elastic spacing of the pressure plate 7 from the closing head 1 and the pressure plate 7 is reset with its rolling surface 6 on the bearing surface 5.

The spring 4 is on the one hand on a spring linkage 2 mounted in the capping head 1 and on the other hand, via a spring bearing pin 8 in a narrowed receiving bore for the same 7 in the pressure plate in the center of the Rollfäche 6 and the bearing surface 5 of a bore 1 ₀ is respectively provided for the passage of the spring. 4 A spring chamber 3 is left within the closing head 1 for the free movement of the spring 4. As shown, the spring 4 is a helical tension spring.

FIG. 2 also shows a cross section through another embodiment of a closing head according to the invention. Here, the curvature of the bearing surface 5 is equal to that of the rolling surface 6. A ball joint is thus formed. Here, too, the center of the curvature of the rolling surface 6 lies in the center of the pressure surface 11 of the pressure plate 7. The springs 4 are provided over the circumference of the pressure plate 7 between the same and the closing head 1. These are also tension springs. The advantage of this embodiment is that the pressure plate 7 does not roll on the bearing surface 5, that is to say the center of the pressure surface 11 does not move from its original position here. A lateral displacement of the pressure plate 7 relative to the cap 9 on the container neck is therefore not to be worried.

It should also be pointed out that instead of the one central spring 4 according to the embodiment in FIG. 1, interacting magnetic elements can be provided, For example, a magnetic north pole on the side of the closing head 1 and a magnetic south pole directed towards it on the side of the pressure plate 7.

Explanation of symbols

• 1 capping head
• 2 spring linkage
• 3 spring chamber
• 4 spring
• 5 storage space
• 6 rolling surface
• 7 pressure plate
• 8 spring bearing bolts
• 9 sealing cap
• 1o hole
• 11 printing area
• 12 0-ring
• 13 groove

Claims (5)

1. closure head (1) with a pressure plate (7) for pressing a closure cap (9) onto a container neck,
characterized,
that the pressure plate (7) has a curved rolling surface (6) with which the pressure plate (7) rests on a bearing surface (5) curved opposite to the rolling surface (6), and that between the closing head (1) and the pressure plate (7 ) at least one spring (4) is arranged, which presses the pressure plate (7) against the rolling surface (6). 2. capping head (1) according to claim 1,
characterized,
that the bearing surface (5) is concave and the rolling surface (6) convex, the curvature of the bearing surface (5) being at most as large as the curvature of the rolling surface (6). 3. capping head (1) according to claim 2,
characterized,
that at least the curvature of the rolling surface (6) is spherical and the center of curvature coincides with the center of the pressure surface (11) of the pressure plate (7). 4. capping head (1) according to claim 2 or 3, characterized in
that the curvature of the bearing surface (5) is smaller than the curvature of the rolling surface (6) and that the at least one spring (4) between the closing head (1) and the pressure plate (7) in the center of the bearing surface (5) and and Pressure plate (6) is arranged. 5. capping head (1) according to at least one of claims 1 to 4,
characterized,
that a circumferential O-ring (12) is arranged in a circumferential groove (13) in the end face of the closing head (1) between the closing head (1) and the pressure plate (7).

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