Expansible press plunger, an attachment unit for attaching a container element to a container body and a method for sealing a packaging container

Patent metadata

Field	Value
Publication number	US-12459690-B2
Application number	US-202118032391-A
Country	US
Kind code	B2
Filing date	Oct 13, 2021
Priority date	Oct 20, 2020
Publication date	Nov 4, 2025
Grant date	Nov 4, 2025

Abstract

A radially expansible press plunger has a base plate, a first expansion tool and a second expansion tool. The first expansion tool and the second expansion tool are movable in relation to each other in the axial direction. The first expansion tool has at least one inclined plane surface. The second expansion tool has at least one inclined plane surface corresponding to the at least one inclined plane surface on the first expansion tool. Each inclined plane surface on the first expansion tool contacts and applies pressure to the corresponding inclined plane surface of the second expansion tool when the expansible press plunger is in the radially expanded state. An attachment unit for attaching a container sealing element to a container body and a method for attaching a container sealing element to a container body are also disclosed.

First claim

The invention claimed is:

1 . An expansible press plunger comprising:
a plunger having a plunger body aligned with a plunger axis extending in an axial direction perpendicular to a radial direction; an expansion tool side wall having an inner surface and an outer surface, the expansion tool side wall defining a cavity within which the plunger body translates along the plunger axis, wherein the outer surface includes a sealing extension protruding from the outer surface and a deformation extension protruding from the outer surface, the side wall being transformable between an unexpanded state and a radially expanded state, wherein the side wall comprises a first inclined plane surface being inclined away from the plunger axis and wherein the plunger body comprises a second inclined plane surface the second inclined plane surface of the plunger body contacting and applying pressure to the corresponding first inclined plane surface of the side wall when the side wall is in the radially expanded state, wherein the side wall is transformable between the unexpanded state and the radially expanded state by movement of the plunger body along the plunger axis downward inside of the side wall wherein the side wall is made of a material which can be repeatedly flexed and/or stretched.

2 . The expansible press plunger in accordance with claim 1 , wherein the first inclined plane surface is inclined at a first angle and wherein the second inclined plane surface is inclined at a second angle, wherein a difference between the first angle and the second angle is from 1° to 3°.

3 . The expansible press plunger in accordance with claim 1 wherein a first distal end of the deformation extension is a greater distance from the plunger axis than a second distal end of the sealing extension.

4 . The expansible press plunger in accordance with claim 3 , wherein the first distal end of the deformation extension moves a first radial distance when the side wall transitions between the unexpanded state and the radially expanded state, and wherein the second distal end of the sealing extension moves a second radial distance when the side wall transitions between the unexpanded state and the radially expanded state, wherein the first radial distance is greater than the second radial distance.

5 . The expansible press plunger in accordance with claim 4 , wherein the deformation extension is proximate a bottom of the side wall and wherein the sealing extension is positioned above the deformation extension.

6 . The expansible press plunger in accordance with claim 1 , further comprising outer tooling within which the plunger and the expansion tool side wall are disposed, the outer tooling having a receiving region that receives at least a portion of the deformation extension when the side wall is in the expanded state.

7 . The expansible press plunger in accordance with claim 1 , wherein an expansion slit is arranged in the side wall, the expansion slit extending in the side wall in the axial direction.

8 . The expansible press plunger in accordance with claim 7 , wherein the side wall has a height in the axial direction, the expansion slit extending in the side wall a distance in a range of from 40% to 100% of the height of the side wall, such as from 40% to 70% or from 45% to 60%.

9 . The expansible press plunger in accordance with claim 7 wherein a plurality of expansion slits extend from a bottom of the side wall towards a top end of the side wall and divide the side wall into a plurality of segments.

10 . The expansible press plunger in accordance with claim 9 , wherein each of the expansion slits of the plurality of expansion slits is terminated at respective end openings, each respective end openings arranged on a hinge line extending in a circumferential direction of the side wall, perpendicular to the axial direction.

11 . The expansible press plunger in accordance with claim 1 , wherein the comprises a sealing extension extends circumferentially on the outer surface of the side wall along all or part of a circumference of the side wall.

12 . The expansible press plunger in accordance with claim 1 , wherein the deformation extension protrudes in the radial direction from the outer surface of the side wall.

13 . The expansible press plunger in accordance with claim 12 , wherein the deformation extension extends circumferentially on the outer surface of the side wall along all or part of a circumference of the side wall.

14 . The expansible press plunger according to claim 12 , wherein the sealing extension is arranged above the deformation extension as in the axial direction.

15 . The expansible press plunger according to claim 1 , wherein the side wall is formed as one integral piece.

16 . An attachment unit for attaching a container sealing element to a container body, the attachment unit comprising an expansible press plunger according claim 1 and a retaining device, the retaining device being adapted to retain the container body, the retaining device comprising at least one through-going positioning cavity being adapted to receive and hold a portion of the container body, the positioning cavity of the retaining device having a cross-sectional area defining a footprint area of the container body, the expansible press plunger being axially movable between an attachment position inside the positioning cavity of the retaining device and a rest position outside the positioning cavity of the retaining device.

17 . An attachment unit according to claim 16 , wherein the retaining device comprises a welding unit comprising an induction coil arranged around the positioning cavity.

18 . An attachment unit according to claim 16 , wherein the positioning cavity of the retaining device comprises an indentation arranged in a wall of the positioning cavity.

19 . A plunger device comprising:
an expansion plunger having a body defining a peripheral surface, the expansion plunger arranged to translate along a vertical axis; an expansion shell disposed around the peripheral surface and aligned with the vertical axis, the expansion shell including:
a wall defined between an inner surface and an outer surface, the inner surface defining a cavity within which the expansion plunger translates;
wherein the outer surface of the expansion shell includes a sealing extension protruding from the outer surface and a deformation extension protruding from the outer surface; and
wherein translation of the expansion plunger moves each of the sealing extension and the deformation extension outward from the vertical axis.

20 . An attachment unit for attaching a container sealing element to a container body, the attachment unit comprising a plunger device according claim 19 and a retaining device, the retaining device being adapted to retain the container body, the retaining device comprising at least one through-going positioning cavity being adapted to receive and hold a portion of the container body, the positioning cavity of the retaining device having a cross-sectional area defining a footprint area of the container body, the plunger device being axially movable between an attachment position inside the positioning cavity of the retaining device and a rest position outside the positioning cavity of the retaining device.

21 . The attachment unit according to claim 20 , wherein the retaining device comprises a welding unit comprising an induction coil arranged around the positioning cavity.

Assignees

• Gpi Systems Ab
• Graphic Packaging Int Llc

Inventors

• Hagelqvist Per

Classifications

• B65B7/2878 Primary

  by heat-sealing · CPC title

• B29L2031/7166

  Cartons of the fruit juice or milk type, i.e. containers of polygonal cross sections formed by folding blanks into a tubular body with end-closing or contents-supporting elements, e.g. gable type containers (in general B65D5/06) · CPC title

• B29C66/849

  Packaging machines · CPC title

• B29C66/8322

  Joining or pressing tools reciprocating along one axis · CPC title

• B29C66/82261

  Wedges · CPC title