Snap-on lid

Abstract

A snap-on lid (1) for closing a receptacle (8) has a platform (2) and a circumferential skirt (3) extending from the platform (2). The circumferential skirt (3) has an inner side (3A) with a snap-on tab (5) for securing the snap-on lid (1) to a ridge on the upper end (82) of the receptacle (8). The platform (2) has an outer ring-shaped zone (2), extending radially from an outer periphery of the platform (2), and radially inward from the outer ring-shaped zone (21) a raised ring-shaped or circular zone (22) that is raised relative to the outer ring-shaped zone (21). A peripheral rim (24) is formed on the outer periphery of the platform, projecting from the platform (2) and having a free end (24A). The free end (24A) of the peripheral rim (24) is raised relative to the outer ring-shaped zone (21).

Description

Snap-on lid

[0001] The invention relates to a snap-on lid for closing a container, said snap-on lid having a cover that, in use, covers one end of the container, and further having a circumferential skirt extending from the cover and having a free end away from the cover, the circumferential skirt having an inner side in which a snap-on flange is formed for securing the snap-on lid to a flange at one end of the container, the cover having an outer annular zone extending radially from an outer periphery of the cover, and the cover having, radially inwards from the outer annular zone, a raised annular or circular zone that is raised with respect to the outer annular zone.

[0002] Such snap-on lids are known, for example, for sealing coffee cans containing ground coffee, and are made of thermoplastic materials. An example of such a lid is disclosed in patent document EP 1561696 A1.

[0003] Currently, the goal is to produce more sustainable products. In the case of plastic snap-on lids, one way to produce more sustainably is to reduce the amount of material used in their manufacture. Generally, this will lead to thinner walls. The snap-on lid is placed on the container on an automated capping line. The lids are fed into the capping line in stacks, then unstacked and placed in a row on a conveyor belt, where they push each other forward. Thin-walled lids cause more failures on such a capping line than conventional lids.

[0004] The present invention aims to provide a thin-walled snap-on cap that overcomes problems in capping lines.

[0005] This objective is achieved by means of a snap-on lid according to the preamble of claim 1, wherein a peripheral rim is formed on the outer periphery of the cover that protrudes from the cover and has a free end, wherein the free end of the peripheral rim is raised with respect to the outer annular area.

[0006] Typically, snap-on caps are supplied to the capping line in stacks, after which they are unstacked and placed on the line. The free end of the skirt of a top cap rests on the outer annular area of ​​the bottom cap. Advantageously, the peripheral rim provides radial retention of the free end of the top cap's skirt, preventing the skirt from slipping off the bottom cap's cover. This prevents feeding failures of the caps to the capping line. In addition, the elevation provided by the peripheral rim also reduces the tendency of one cap to slide over an adjacent cap as the caps push against each other while being conveyed on the capping line.

[0007] The peripheral rim has a beneficial effect on the rigidity of the cap. Thus, the cap generally has less tendency to deform when pushed forward on a capping line where the caps are arranged in a row, with one cap pushing the other in the direction of transport. However, the peripheral rim itself is flexible and can deform when it is on the line and presses against another peripheral rim. In this way, the skirts of consecutive caps on the line can mesh together, giving the caps on the line the same behavior as conventional snap-on caps when pushed forward on the capping line.

[0008] In one embodiment of the lid, the peripheral edge has a radially inward-facing conical surface. This inward-facing conical surface guides the free end of the skirt of the lid above it toward the surface of the outer annular area. In this way, the free end of the skirt of the upper lid is held firmly in position, and the stack of lids remains straight and stable.

[0009] In a further embodiment, the peripheral skirt has a recess at its free end, said recess having an outer diameter smaller than the inner diameter of the inward-facing surface of the peripheral edge. The recess at the free end of the skirt and the inward-facing surface of the peripheral edge cooperate and improve the stability of the stacked lids.

[0010] In one embodiment, the peripheral rim is radially flared outward relative to the circumferential skirt. The flared peripheral rim not only provides the inwardly oriented, radially tapered surface, but also reduces the tendency of one cap to slip over an adjacent cap as the caps push against each other during transport on the capping line. Furthermore, it provides increased cap stiffness while using minimal additional material. Advantageously, the flared rim is flexible, so that it can be pushed inward locally when aligned with other caps on the capping line, allowing the skirts of consecutive caps to mesh together and the caps to behave in the same manner on the line as conventional caps without such a rim.

[0011] In one embodiment, the raised annular or circular area has an outer diameter adapted to substantially engage with a lower face of a container, thereby facilitating the stacking of containers with a lid. Stacking containers with a lid is useful during transport, storage, or display in a shop.

[0012] In one embodiment, the cover has a raised annular zone and a recessed central circular zone that is lower than the outer annular zone. The recessed central circular zone provides additional rigidity to the cover, reducing deformation and the risk that such deformation will cause the capping line covers to slide over each other and obstruct the line.

[0013] The snap-on lid according to the invention is manufactured by an injection molding process from a thermoplastic material, preferably PE. A suitable material has been determined to be a mixture of HDPE and LDPE. The lid can have a thickness in the range of 0.3–0.7 mm, preferably in the range of 0.4–0.6 mm, and preferably approximately 0.5 mm. The skirt can have a thickness in the range of 0.3–0.7 mm, preferably in the range of 0.4–0.6 mm. Of course, the thickness of the skirt is greater at the snap-on flange and need not be within this range.

[0014] The lid may have a diameter within a range of 70 mm to 160 mm, depending on the specific container with which it is combined. In one specific embodiment, the skirt has an outside diameter of approximately 130 mm, resulting in a lid weight of approximately 8.3 g. In another specific embodiment, the skirt has an outside diameter of approximately 99 mm, resulting in a weight of approximately 5.5 g. These snap-on lids can be considered lightweight. Specific embodiments having other diameters, such as 153 mm or 70 mm, are also provided for.

[0015] The invention also relates to an assembly of a container having a flange at the upper end near an open upper end of the container and a snap-on lid as described above.

[0016] The invention further relates to a method for sealing a container with a snap-on lid as described above, wherein: - The snap-on caps are supplied to a capping line in a stack; - the snap-on lids are destacked and placed one after the other on a conveyor line, where the lids are pushed against each other in a radial direction; and - The snap-on lids are individually removed from the conveyor line and placed on the container.

[0017] The invention also relates to a container provided with a lid, wherein the container is covered with a snap-on lid of the type described above.

[0018] The invention also relates to a stack of such containers provided with a lid.

[0019] The invention will be explained in the following description with reference to the drawings, in which: Fig. 1 shows a cross-section of a snap-on lid according to the invention, Fig. 2 shows a detail of the cross-section of Fig. 1, Fig. 3 illustrates a cross-section of a stack of lids from Fig. 1, Fig. 4 illustrates the caps of Fig. 1 arranged in a line on a capping line, Figure 5 illustrates in cross-section how the containers with a lid are stacked, and Fig. 6 illustrates in isometric view the stacking of containers provided with a lid.

[0020] Fig. 1 shows a snap-on lid 1 for fitting over an open top end of a container. The container is, in general, a cylindrical vessel with a closed bottom and an open top end. The snap-on lid 1 has a cover 2, which, in use, covers the open top end of the container. The snap-on lid 1 further has a circumferential skirt 3 extending from the cover 2 and having a free end 31 away from the cover 2. The circumferential skirt 3 has an inner side 3A in which a circumferential snap-on flange 5 is formed for securing the snap-on lid 1 to a flange at the top end of the container. In the case of a cylindrical receptacle, the skirt 3 can also be substantially cylindrical, as is the case in the embodiment shown in Fig. 1.

[0021] Cover 2 has an outer annular zone 21 extending radially from an outer periphery of the cover. The cover also has, radially inwards from the outer annular zone 21, a raised annular zone 22, which is raised relative to the outer annular zone 21. Cover 2 has a recessed central circular zone 23 that is lower than the outer annular zone 21. The height transitions between zones 21, 22, and 23 provide the cover with greater rigidity. In one possible embodiment, not shown in the figures, the recessed circular zone 23 can be omitted, so that instead of a raised annular zone 21, the cover has a raised circular zone.

[0022] A peripheral rim 24 is formed on the outer periphery of the cover 2, projecting from the cover 2 and having a free end 24A (see Fig. 2). The free end 24A of the peripheral rim 24 is raised with respect to the outer annular zone 21. In other words, the free end 24A of the peripheral rim 24 is separated from the surface of the annular zone 21 in an axial direction of the snap-on cover 1. The peripheral rim 24 extends in a direction away from the skirt 3; that is, if the skirt 3 extends downward, as is the case during normal use when placed on a receptacle, the peripheral rim 24 extends upward, although not at an angle of 180° (in line) with respect to the skirt 3, but at a smaller angle. The peripheral edge 24 widens radially outwards with respect to the circumferential skirt 3. The peripheral edge 24 has a radially inwards oriented conical surface 24B (see Fig. 2).

[0023] At the free end 31, which during normal use is the lower end, the peripheral skirt 3 has a recess 32, said recess 32 having an outside diameter smaller than the inside diameter of the inward-facing surface 24B of the peripheral edge 24. In the embodiment shown in the figures, the recess 32 is chamfered.

[0024] Figure 3 illustrates a stack of snap-on caps 1. Typically, snap-on caps 1 are arranged on the capping line in stacks of this type of cap 1, after which they are unstacked and placed in line (see Figure 4). The free end 31 of the skirt 3 of an upper cap rests on the outer annular area 21 of the cap 1 below. Advantageously, the peripheral rim 24 provides radial retention of the free end 31 of the skirt 3 of the upper cap 1, preventing the skirt 3 of the upper cap 1 from slipping off the cover 2 of the lower cap 1. This prevents feeding failures of the caps 1 to the capping line.

[0025] The inwardly facing conical surface 25B, in the radial direction, guides the free end 31 of the skirt 1 of the lid 1 above it toward the surface of the outer annular zone 21. In this way, the free end 31 of the skirt 3 of the lid 1 above it is held firmly in position, so that the stack remains straight upward and stable. The recess 32 in the free end 31 of the skirt 3 and the inwardly facing surface 24B of the peripheral edge 23 cooperate and enhance the stability of the stacked lids 1.

[0026] The peripheral rim 24 is flexible. When the lids 1 are unstacked and placed in a line for conveying one after the other, the skirts 3 of consecutive lids 1 are pushed against each other. In the lid 1 according to the invention, the peripheral rim 24 can deform inwards due to its flexibility, so that the skirts 3 can effectively engage with each other. This is illustrated in Fig. 4 and indicated by an arrow. The lids 1 are moved by an endless conveyor element 6 located beneath a plate 7.

[0027] Snap-on lid 1 is placed over an open upper end of a container 8, as shown in Fig. 5 and 6. Cover 2 covers the open upper end of the container 8. The snap-on flange 5 formed on the inside side of the skirt 3 secures snap-on lid 1 to a flange on the upper end 82 of the container 8.

[0028] The raised annular zone 21 has an outer diameter adapted to fit substantially with a flange at the lower end 81 of a container 8, thereby facilitating the stacking of containers fitted with a lid (see Figs. 5 and 6). Stacking containers fitted with a lid is useful during transport, storage, or display in a shop.

[0029] The snap-on lid 1 according to the invention is manufactured by an injection molding process from a thermoplastic material, preferably a PE, for example, a mixture of HDPE and LDPE. The cover 2 can have a thickness in the range of 0.4 mm - 0.6 mm, preferably approximately 0.5 mm. The skirt 3 can have a thickness in the range of 0.4 mm - 0.6 mm.

[0030] The lid 1 can have a diameter in the range of 80 mm - 140 mm, depending on the specific container with which it is combined. In the specific embodiment shown in the figures, the skirt 3 has an outer diameter of approximately 130 mm, resulting in a weight of lid 1 of approximately 8.3 g, which can be considered light.

Claims

1. A snap-on lid (1) for closing a container (8), said snap-on lid (1) having a cover (2) which, in use, covers one end of the container (8), and further having a circumferential skirt (3) extending from the cover (2) and having a free end (31) away from the cover (2), the circumferential skirt (3) having an inner side (3A) in which a snap-on flange (5) is formed for securing the snap-on lid (1) to an end flange (82) of the container (8), the cover (2) having an outer annular zone (21) extending radially from an outer periphery of the cover (2), and the cover (2) having, radially inwards from the outer annular zone (21), a raised annular or circular zone (22) that is raised with respect to the outer annular zone (21),characterized in that a peripheral edge (24) is formed on the outer periphery of the cover, projecting from the cover (2) and having a free end (24A), wherein the free end (24A) of the peripheral edge (24) is raised with respect to the outer annular zone (21).

2. Snap-on cover according to claim 1, wherein the peripheral edge (24) has an inwardly oriented radial conical surface (24B).

3. Snap-on cover according to claim 1 or 2, wherein the peripheral edge (24) widens outwardly with respect to the circumferential skirt (3).

4. Snap-on cover according to claim 2, wherein the peripheral skirt (3) has a recess (32) at the free end (31), said recess (32) having an outer diameter smaller than the inner diameter of the inwardly oriented surface (24B) of the peripheral edge (24).

5. Snap-on lid according to any of the preceding claims,wherein the cover (2) has said raised annular zone (22) and a recessed central circular zone (23) that is lower than the outer annular zone (21).

6. Snap-on cover according to any of the preceding claims, made of a thermoplastic material.

7. Snap-on cover according to claim 6, wherein the cover (2) has a thickness in the range of 0.4 mm - 0.6 mm, preferably approximately 0.5 mm.

8. Snap-on cover according to claim 6 or 7, wherein the skirt (3) has a thickness in the range of 0.4 mm - 0.6 mm.

9. Snap-on cover according to any of claims 6-8, wherein the snap-on cover (1) has a diameter in the range of 80 mm - 140 mm.

10. An assembly comprising a receptacle (8) having an upper end flange (82) near the upper end of the receptacle (8) and a snap-on lid (1) according to any of the preceding claims.

11. An assembly according to claim 10.wherein the container (8) has a lower face, and wherein the raised annular or circular area (22) has an outer diameter adapted to substantially align with said lower face of the container (8), thereby facilitating the stacking of containers provided with a lid.

12. Method for sealing a container (8) with a snap-on lid (1) according to any one of claims 1-9, wherein: - the snap-on lids (1) are arranged in a stack on a sealing line; - the snap-on lids (1) are unstacked and placed one after the other on a conveyor line, wherein the snap-on lids (1) are pushed against each other radially; - the snap-on lids (1) are individually removed from the conveyor line and placed onto the container (8).

13. Container provided with a lid, wherein the container has an upper end flange (82) near the upper end of the container (8),and a snap-on lid (1) according to any of claims 1-9 fixed to the upper end flange (82) of the container (8) by means of the snap-on flange (5) formed on the inner side of the skirt (3) of the snap-on lid (1).

14. Stack of containers provided with a lid according to claim 13.,

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