Flip-top closure

Abstract

The invention relates to a flip-top closure (11) having a cap (13), which is fastenable to a neck of a container and has a jacket (17), a cover plate (19) adjoining the jacket (17), and a removal opening (21) provided on the cover plate (19), and a hinged lid (15), which is connected to the cap (13) by a hinge and has a sealing nipple (23) provided on its inner side, which hinged cover (15) is pivotable by means of the hinge between a closure position and an open position and snaps in place in both positions. The hinge is realised by two tension strips (25a, 25b) and a middle web (27) with a length (31) and a width, the first ends of which are integrally moulded on the jacket (17) and the second ends of which are integrally moulded on the hinged lid (15). An elevation (33) for defining a pivot point of the middle web (27) is formed at the transition from the jacket (17) to the cover plate (19), above the middle web (27).

Description

[0001] Flip-top closure

[0002] Field of the invention

[0003] The invention relates to a flip-top closure according to the preamble of claim 1.

[0004] State of the art

[0005] A flip-top closure is typically understood to be a closure with a cap and a hinged lid connected to the cap. The hinged lid can be pivoted or snapped between two defined positions, namely a closed and an open position. To enable this function, it is known to form the articulated connection between the cap and hinged lid using two drawstrings and a central web. The hinge, realized by the two drawstrings and the central web, thus has an active behavior with the hinged lid opening and closing automatically once a defined limit is exceeded. For the purposes of this application, a flip-top closure is therefore understood to be a closure according to the above description.

[0006] In the prior art, the center bar has a weakened line at the pivot point to form a kind of film hinge. Other material thinnings or weakenings in the area of ​​the center bar are also already known to implement the locking or snapping function (often referred to as a butterfly function).

[0007] However, these material weaknesses in the center bar repeatedly lead to the center bar tearing, completely losing the locking function of the closure. This type of flip-top closure is also primarily suitable for polypropylene, as this plastic is less elastic than, for example, HDPE.

[0008] Object of the invention

[0009] The disadvantages of the described prior art give rise to the task of creating a flip-top closure in which lower stresses occur during the actuation of the hinged lid. This stress reduction leads to a lower tendency for the center bar to crack and the possibility of using more elastic plastics. Description

[0010] The stated problem is solved with a flip-top closure by the features stated in the characterizing portion of patent claim 1. Further developments and / or advantageous embodiments are the subject of the dependent patent claims.

[0011] The invention is preferably characterized in that a raised portion is formed at the transition from the shell to the lid above the central web to define a pivot point for the central web. This allows the central web to move flexibly without being subjected to compression or tensile stress. Consequently, the central web is subjected to less mechanical stress, and its service life is increased accordingly. The raised portion provides a pivot point for the central web, so that the flip-top snap-lock function is maintained in the open and closed positions.

[0012] In a particularly preferred embodiment of the invention, the central web is free of a weakened portion, which forms a crease line of the central web. Undesirable tearing of the central web at the weakened portion cannot be avoided with known flip-top closures, since the crease line is necessary for the "active behavior" of the closure. In the closure according to the invention, the function of the crease line is taken over by the raised portion, which reliably reduces the tearing of the hinge and, ideally, prevents it for the entire service life of the closure.

[0013] It has proven useful to provide a circumferential step at the transition from the shell to the cover plate, on which the raised portion is formed. This optimally positions the raised portion to act as the pivot point or inflection point for interaction with the central web. Furthermore, the raised portion can be easily removed from an injection mold at the step.

[0014] In a further preferred embodiment of the invention, the raised portion has an edge against which the central web rests when pivoting from the open position to the closed position. This edge enables a precisely defined pivot point for the central web, necessary for snapping the lid flap into place in the open and closed positions.

[0015] Because the edge is oriented in the direction of the width of the central web, the central web rests symmetrically on the raised portion and is deflected symmetrically at the raised portion. The raised portion is conveniently positioned midway between the two tension straps, further improving the symmetrical and even engagement of the edge on the central web described in the last paragraph.

[0016] In a further preferred embodiment of the invention, the raised portion has a height between 0.5 and 3 mm. The height of the raised portion or pivot point can be precisely adjusted in the casting tool. Even existing tools can be supplemented with the negative impression of the raised portion. By precisely adjusting the height, stresses in the lid flap can be reduced.

[0017] Preferably, the height of the raised portion corresponds to half the length of the center bar. This ensures that the edge engages exactly in the middle of the center bar to deflect the center bar.

[0018] It is advantageous if the raised portion is rounded along the circumference of the shell. This simplifies demolding.

[0019] The invention is also preferably characterized in that both the cap and the hinged lid are free of reinforcing ribs. Since the resulting stresses are reduced, reinforcing ribs, which serve to compensate for stress in previously known flip-top closures, can be omitted. This reduces the weight and material used in the closure, and the closure is not deformed by ribs. The removal process is also simplified by the elimination of ribs.

[0020] In a particularly preferred embodiment of the invention, the closure is made of HDPE. Since HDPE is more elastic than PP, the tension in the drawstrings would have to be increased by 35-40% to achieve the same closure function as with PP. However, increasing the tension increases the warpage of the cap and the hinged lid. Therefore, HDPE cannot be used in previously known flip-top closures. The flexibly movable center bar compensates for tension, allowing HDPE to be used for the flip-top closure.

[0021] In a further preferred embodiment, the closure is made of PP. In existing flip-top closures made of PP, distortion and compression of the drawstrings and the central rib, as well as deformation of the cap and the hinged lid, as well as tearing of the drawstrings and the central rib due to excessive tension, are known. The closure according to the invention is therefore also suitable for closures made of PP, as it solves these problems through the flexible, unweakened central rib in combination with the raised portion.

[0022] The closure is preferably injection-molded. The raised portion can be easily formed in an injection-molding tool. The height of the raised portion can be changed by adjusting the tool. It is also possible to adapt existing tools so that molded closures incorporate the raised portion.

[0023] Further advantages and features will become apparent from the following description of an embodiment of the invention with reference to the schematic representations. These are not to scale:

[0024] Figure 1 : a top view of a flip-top lock

[0025] Figure 2: a sectional view along the line ll-ll of Figure 1;

[0026] Figure 3: a first axonometric view of the flip-top closure and

[0027] Figure 4: a second axonometric view of the flip-top closure.

[0028] Figures 1 to 4 show a flip-top closure according to the definition in the introduction, which is designated overall by reference numeral 11 and is preferably manufactured using an injection mold. The closure 11 comprises a cap 13 that can be attached to the neck of a container and a hinged lid 15 that is pivotally connected to the cap. The cap 13 can, for example, be screwed onto the container neck or can be snapped onto it.

[0029] The cap 13 has a jacket 17, a cover plate 19 adjoining the jacket 17, and a removal opening 21 provided on the cover plate 19. The hinged lid 15 is connected to the cap 13 by a joint. A sealing nipple 23 is provided on the inside of the hinged lid 15, which cooperates sealingly with the removal opening 21 when the closure 11 is closed. The hinged lid 15 can be pivoted between a closed position and an open position using the joint and snaps into place in both positions.

[0030] The joint is realized by two tension bands 25a, 25b and a central web 27 with a width of 29 and a length of 31. The first ends of the tension bands 25a, 25b and the central web 27 are formed on the casing 17, and their second ends are formed on the hinged lid 15. The interaction of the tension bands 25a, 25b and the central web 27 allows the hinged lid 15 to snap into the open and closed positions. The joint therefore exhibits an active behavior in that it opens and closes automatically when a defined tension is exceeded.

[0031] At the transition from the jacket 17 to the cover disc 19 above the central web 27, a raised portion 33 is formed to define a pivot point for the central web. This allows the central web 27 to be deflected in a defined manner when the hinged lid 15 is moved between positions at the raised portion 33. A conventional weakening line, where the central web bends, is no longer necessary with the central web 27. This has the significant advantage that there is no weakening at the central web 27 where the central web could accidentally tear. Furthermore, the stresses can be reduced to create an "active" joint with snap-in positions. This eliminates the need for reinforcing ribs, which compensate for the stresses, can deform the closure, complicate demolding, and require a lot of material.

[0032] At the transition from the casing 17 to the lid disc 19, a circumferential step 35 is formed, onto which the hinged lid 15 can latch in the closed position. The elevation 33 is formed on the step 35. For a defined deflection of the central web 27 at the elevation 35, the elevation 35 has an edge 37, against which the central web 27 rests and is deflected. The central web 27 can move freely and is guided by the elevation 33, whereby it is subject to much lower mechanical stresses than a central web in a prior art flip-top closure. The edge is expediently oriented in the direction of the width 29 of the central web 27, so that the guidance of the central web is symmetrical and defined. For this reason, the elevation 33 is also positioned centrally between the two tension straps 25a, 25b. Preferably, the elevation 33 is rounded in the circumferential direction of the jacket 17 in order to simplify demoulding from the injection mould.The elevation can have a height of between 0.5 and 3 mm. The pivot point height or the edge height can be defined in the injection mold and reworked with little effort, thereby optimizing the function of the closure 11. The closure 11 can also be molded in existing tools, as these can be supplemented with a corresponding recess for the elevation. Flip-top closures are usually made of PP (polypropylene) because PP is less elastic than HDPE (high-density polyethylene). According to the state of the art, a flip-top closure made of HDPE would not function or would function only poorly. The closure 11 is particularly suitable for HDPE due to its "flexible" center bar and the resulting ability to compensate for high stresses.

[0033] But even when using PP (polypropylene), the innovative closure 11 is justified. Since the stresses are lower, the need for reinforcement grooves is eliminated, as already described. Furthermore, the tearing of the central web 27 is prevented, as the stresses and compression acting on the central web 27 are reduced. The central web 27 tears due to the lower load and the absence of a

[0034] Kinks are much less common. The joint therefore has a longer lifespan.

[0035] Legend:

[0036] 11 Flip-Top closure

[0037] 13 cap

[0038] 15 hinged lids

[0039] 17 Coat

[0040] 19 Cover disc

[0041] 21 Removal opening

[0042] 23 sealing nipples

[0043] 25a, 25b Drawstrings

[0044] 27 Central bridge

[0045] 29 Width of the center bar

[0046] 31 Length of the central bar

[0047] 33 Survey

[0048] 35 level

[0049] 37 Edge of the elevation

Claims

The flip-top closure (11) comprises a cap (13) attachable to the neck of a container, the cap (13) having a sleeve (17), a lid disc (19) adjoining the sleeve (17), and a dispensing opening (21) provided on the lid disc (19), and a hinged lid (15) connected to the cap (13) by a hinge, the lid (15) having a sealing nipple (23) provided on its inside, the hinged lid (15) being pivotable between a closed position and an open position and snapping into place in both positions, the hinge being realized by two tension bands (25a, 25b) and a central web (27) having a length (31) and a width (29), the first ends of which are formed on the sleeve (17) and the second ends of which are formed on the hinged lid (15), characterized in that a projection (33) is provided at the transition from the sleeve (17) to the lid disc (19) above the central web (27) to define a The pivot point of the central web (27) is formed.A closure according to claim 1, characterized in that the central web (27) is free from a weakening that forms a fold line of the central web (27). A closure according to claim 1 or 2, characterized in that a circumferential step (35) is formed at the transition from the sleeve (17) to the cover disc (19), on which the projection (33) is formed. A closure according to any one of the preceding claims, characterized in that the projection (33) has an edge (37) against which the central web (27) rests when pivoting from the open position to the closed position. A closure according to claim 4, characterized in that the edge (37) is oriented in the direction of the width (29) of the central web (27). A closure according to any one of the preceding claims, characterized in that the projection (33) is positioned in the middle between the two pull straps (25a, 25b).

7. Closure according to one of the preceding claims, characterized in that the protrusion (33) has a height between 0.5 and 3 mm.

8. Closure according to any one of the preceding claims, characterized in that the protrusion (33) is rounded in the circumferential direction of the sleeve (17).

9. Closure according to any one of the preceding claims, characterized in that both the cap (13) and the hinged lid (15) are free of reinforcing ribs.

10. Closure according to any one of the preceding claims, characterized in that the closure (11) is made of HDPE.

11. Closure according to any one of claims 1 to 9, characterized in that the closure (11) is made of PP.

12. Closure according to one of the preceding claims, characterized in that the closure (11) is injection molded.

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