DE102011015004B4 - External thread for the neck of plastic containers - Google Patents

Abstract

The invention has for its object to provide an external thread for the neck of plastic containers, which in addition to a simple, reliable, optimal centering various types of screw cap on the neck portion of the plastic container at the same time a simple, reliable, optimal, repeatable at each "twisting" rotation of these different Screw caps already ensured with slightly "tightened" thread, and in the end position, ie in firmly screwed on the neck portion of the plastic container screw cap, this effect to be achieved significantly reinforced, and thereby causes a very high anti-rotation of the screw especially for the transport of the plastic container. The external thread (1) according to the invention for the neck part (2) of plastic containers (3 ) is characterized in particular by the fact that several double-wedge Zentrierrastsegmente (5) with stopper flanks (6) are arranged on the pressurized thread flank distributed over each thread of the external thread (1), whereby in the screwing direction of the screw cap (4) the double-wedge Zentrierrastsegmente (5) are formed so that both their wedge thickness (D) relative to the pressure side of the external thread (1), as well as over the core diameter of the external thread (1) of the neck portion (2) protruding wedge height (H) increases up to the stopper edge (6) and there sawtooth aborts.The inventun g relates to an external thread for the neck part of plastic containers on which screw caps are arranged.

Description

The invention relates to an external thread for the neck part of plastic containers on which screw caps are arranged with an external thread zugeordeten internal thread.

In the prior art, plastic containers with a neck portion carrying an external thread, on which screw caps are arranged, are often described above.

Characteristic of the screw on plastic containers is that between the tips of the interlocking thread profiles and the core diameters of the mating thread a very large game is present, resulting from unavoidable manufacturing tolerances.

This inevitable cycle in the thread on plastic containers is one reason why screw caps on plastic containers after tightening the screw cap have the tendency to loosen again.

Such a "loosening" of the screw can occur, for example, when the arranged in the screw cap seal relaxes.

On the other hand, such a "loosening" of the screw connection can occur even if, for example, when transporting the sealed plastic container of the screw is exposed shocks, or even if actuators, such as spray bottles spray guns are arranged on the screw cap, and these are used.

In order to avoid such a loosening of the screw caps in plastic containers usually during transport, different approaches have become known in the art.

One solution is screw-type screw-type fuses with predetermined breaking points. In this solution variant, a lock of the cap in the lower end position on the respective container is effected after filling the respective container, the first time screwing the cap, the various types of such Schraubverschluß fuses are pre-described with predetermined breaking points in the prior art.

However, this approach of a screw cap fuse with predetermined breaking point always requires a special cap - container neck combination, so that the special components provided with predetermined breaking points can come into operative connection after the first filling of the plastic container.

However, they usually never allow the use of different "break-off caps" on one and the same container neck.

This locking of the screw caps on the container neck by means of special predetermined breaking points causes desired after factory filling, non-positive, one-time locking the cap on the container for transporting the filled plastic container to the consumer, but only until the first opening of the screw cap.

After opening such "break-off closures" for the first time, it is no longer possible to guarantee a further screw-lock closure.

On the other hand, the inevitable large working cycle in the thread on plastic containers is also the reason why the screw caps on the thread of the neck parts of the plastic containers can easily be "over-turned".

This "over-turning" always occurs when the threaded connection on the respective plastic container is insufficiently "centered".

For example, if the screw caps with the thread of the neck portion "uncentered" connected, it is often the case that the screw cap on the neck comes off-center, so that on one side of the cap no play between the two threads (outside / inside) available while there is a bigger game on the opposite side.

Under certain conditions now has the material of the screw caps, in such eccentric unscrewing, the tendency to locally deform at the point of the largest game and uses it increasingly from, so that after repeated tightening the engaged threads in place of the largest game on top of each other, d. H. "Snap out", so that the screw cap can no longer be clamped securely on the neck part.

Therefore, in the cover bottoms of the screw caps and / or on the lower edge of the threaded part at the bottleneck often centering, such as centering and / or Zentrierbünde introduced, which interact with arranged on the adjacent component positioning elements and ensure centered screwing.

These elements cause, since the components can always only "pairwise" interact with each other, not a multivalent use of different screw caps on a uniform neck part (with screw thread).

Other types, such as those in the GB 1 172 608 B above-described design, now trying both problems, ie to solve the rotation and the centering simultaneously.

However, this succeeds only conditionally only in caps in end position, d. H. only with caps screwed firmly onto the container neck.

In the GB 1 172 608 B It is proposed to combine either a symmetrical normal thread on the neck part with an asymmetrical thread in the screw cap, or a single-ended thread on the neck part with a symmetrical normal thread in the screw cap, the respective unbalanced thread characterized in that along the pressurized thread flank a is arranged over the entire thread length extending step-shaped approach.

In this design, the axial pressure between the opening on the neck part and the lid underside of the screw cap causes the outer edge of the normal thread to run onto the step-like projection while the screw cap is centered on the neck part, and during "tightening" , d. H. when "firmly" unscrewing, then the two threads on top of each other so far postponed until braced in the (firmly screwed) end position, for example, the thread of the screw cap in the step-shaped approach of the adjacent thread flank of the neck.

When loosening the screw cap after "unscrewing" this "tension" is not loosened immediately, but the "thread" must first be screwed on again until the gap distance in the area of the lid surface is sufficient to the screw cap towards the bottom of the bottle so far to press down, that the nominal thread of the stepped approach of the adjacent thread flank comes free, d. H. that only by pressing down the screw cap, the "tension of the two mutually" strained "thread" solved, and thus the screw lock described above can be unlocked again.

The disadvantage of these designs after the GB 1 172 608 B However, this is that even with this solution again a screw can be guaranteed only in the firmly screwed end position.

However, plastic bottles are also very commonly used with spray guns in many types of cleaning, furniture care, window deicers and the like. a. m. used.

By means of a pump mechanism integrated in the spray gun, the contents are atomized via a special nozzle and applied very finely.

If, for example, a free rotation of the atomizer relative to the main body of the spray bottles in intermediate positions of the screw cap on the thread of the neck part desired, this solution has after the GB 1 172 608 B the disadvantage that the screwing "automatically" dissolves during use of the atomizer.

The spray guns are usually with a screw cap (union nut) on the thread on the neck portion of the corresponding plastic container, such as a plastic bottle attached.

These union nuts have neither centering nor they are fixed by means of predetermined breaking points in end positions on the neck portion of the respective plastic container.

Only when "tightening" (the screw cap on the thread on the neck part) produced bias causes a seal, which is located in the cap, a seal of the container, usually a bottle, and thus secures their contents before leakage.

Such spray bottles are filled industrially on automated filling lines, and usually transported with the help of an outer packaging for retail. Such bottles are also used in the mail order, and there individually but mostly with other products shipped together with a package.

During transport, whether by the customer from the retailer, (along with other products) to home, or in the package of mail order, it may happen that by shocks and small shocks, or by lessening the bias of the gasket on the neck , as already explained, the union nut loosens and then z. B. leaking bottle expires this.

With multiple use of such spray bottles is due to lack of centering In addition, also the already explained danger of overspeeding.

The invention has therefore set itself the goal of eliminating the aforementioned disadvantages of the prior art and to provide an external thread for the neck of plastic containers, which in addition to a simple, reliable, optimal centering various screw caps on the neck portion of the plastic container at the same time a simple, reliable , optimal, with each "twisting" repeatable rotation of these different screw caps even with slightly "tightened" thread ensures, and in the end position, d. H. when firmly screwed on the neck portion of the plastic container screw cap, this effect to be significantly increased again, and thereby causes a very high security against rotation of the screw, in particular for the transport of the plastic container.

According to the invention this object is achieved by an external thread for the neck portion of plastic containers with the features of the independent claim of the invention.

The external thread for the neck of plastic containers, on which screw caps are arranged with an external thread associated with the internal thread, is characterized according to an embodiment in that on the pressurized thread flank, d. H. the screw when screwing the screw cap with pressurized thread flank, distributed over each thread of the external thread distributed a plurality of wedge-shaped Zentrierrastsegmente with stopper flanks, wherein in Schraubrichtung the Schraubverschlusskappe these doppelkeilförmigen Zentrierrastsegmente are formed such that both their wedge thickness relative to the pressure side of the external thread, as well as their over the wedge height projecting beyond the core diameter of the external thread of the neck portion increases until it reaches the stopper flank and breaks off there in a sawtooth manner.

The increasing in the course of the thread wedge thickness of the Zentrierrastsegmente opposite the pressure side of the external thread causes a simple, reliable and optimal centering of different screw caps on the neck portion of the plastic container.

According to one embodiment, it is also thought in this context that the wedge height in the region of the stopper flank, i. H. the flank wedge height, about 40% to 70% of the thread pitch of the external thread over the thread core diameter of the neck portion, whereby in the stopper flank, even with larger working cycles always a reliable centering can be guaranteed.

It is typical that the wedge thickness in the region of the stopper flank, i. H. the flank groove thickness, about 60% to 100% of the thread thickness of the external thread of the neck portion at the core diameter, d. H. at the root of the thread, so that in the area of the stopper flank, even with larger working cycles, the thread coming out of the action can always be guaranteed a reliable rotation.

The on the pressure side of the thread flank of the external thread distributed over each thread multiply arranged double wedge Zentrierrastsegmente with the stopper flanks also cause when screwing the screw cap elastic deformation on the thread of the screw cap in the way that in the stopper flank located wedge tips of Zentrierrastsegmente the thread of the screw cap already elastically deform with slightly tightened thread, and thus to ensure a simple, reliable, optimal anti-rotation of the screw with a variety of screw caps on the external thread even with slightly on the thread on the neck portion of the plastic container tightened screw cap.

When "screwing" these different screw caps, a force acting in the axial direction biasing force is also generated between the respective Schraubverschlusskappe and the neck portion of the plastic container, which now significantly increases the already described penetration of the wedge tips of the Zentrierrastsegmente in the thread of the Schraubverschlusskappe in the region of the stopper and thereby ensures a very high security against rotation of the screw, in particular for the transport of the plastic container.

Advantageous embodiments and details of the invention will become apparent from the following description of an embodiment of the invention solution in conjunction with four representations.

• 1: eine räumliche Darstellung eines Kunststoffbehälters 3, einer Sprühflasche mit einer Sprühpistole 8 und einer am Halsteil der Sprühflasche angeordneten Schraubverschlusskappe 4 ;
• 2: das erfindungsgemäße Halsteil 2 der in der 1 dargestellten Sprühflasche mit einer am findungsgemäßen Halsteil 2 angeordneten Schraubverschlusskappe 4 im Teilschnitt;
• 3: den Schnitt bei A-A, gemäß 2, durch das Halsteil 2, jedoch ohne die am Halsteil 2 angeordnete Schraubverschlusskappe 4 ;
• 4: die Einzelheit X gemäß 3.

It show the following:

• 1 a spatial representation of a plastic container 3, a spray bottle with a spray gun 8 and arranged on the neck portion of the spray bottle screw cap 4;
• 2 : the neck part 2 of the invention in the 1 illustrated spray bottle with a in accordance with the invention neck part 2 arranged screw cap 4 in partial section;
• 3 : the cut at AA, according to 2 through the neck part 2, but without the screw cap 4 arranged on the neck part 2;
• 4 : the detail X according to 3 ,

The Indian 1 illustrated plastic container 3 , in the form of a spray bottle with a spray gun 8th , and one on the neck part according to the invention 2 the spray bottle arranged, commercially available screw cap 4 is in the 2 , to illustrate the subject invention, shown in partial section.

In conjunction with spray guns 8th Be used on plastic containers mostly threads with a core diameter of about 28 mm.

The 2 shows in conjunction with the 3 the inventive design of the printed pages of the thread flanks with the invention, over each thread of the external thread 1 distributed according to the invention arranged, double wedge-shaped Zentrierrastsegmenten 5 , which always end in Stopperflanken 6.

This in screwing the screw cap 4 double wedge-shaped Zentrierrastsegmente 5 are designed so that they both in the wedge thickness D opposite the pressure side of the external thread 1 , as well as in the over the core diameter of the external thread 1 of the neck 2 protruding wedge height H continuously until reaching the stopper edge 6 increase and then at the stopper flank 6 each end in a sawtooth manner.

The continuously increasing over the course of the thread wedge height H the Zentrierrastsegmente 5 opposite the pressure side of the external thread 1 causes, for example, present in the present embodiment thread pitch H _G of external thread 1 of 1.2 mm in conjunction with a flank wedge height H _O of 0.7 mm of the stopper flank 6 , an optimal centering of the screw cap on the neck part 2 of the respective plastic container 3 , in the present case on the neck of a spray bottle.

These invention on the pressure side of the thread flank of the external thread 1 uniformly distributed over each thread on the circumference, quadruple in the present exemplary embodiment, arranged distributed double-key Zentrierrastsegmente 5 cause when screwing the screw cap 4 in addition to the described centering at the same time an elastic deformation of the screw cap 4 on the thread according to the invention.

In the present embodiment, the thread thickness of the external thread 1 in the core diameter, ie at the thread root, D _G = 1.68 mm, and the flank thickness of the Zentrierrastsegmentes 5 in the area of the stopper flank 6 . D _O = 1.44 mm.

The arrangement according to the invention now causes the wedge tips of the invention, and according to the invention on the neck part 2 of the plastic container 3 arranged Zentrierrastsegmente 5 the thread 7 the screw cap 4 deform elastically and besides the centering of the screw cap on the neck part 2 at the same time a rotation of the screw already with slightly tightened thread, and not only in the end position firmly on the neck part 2 of the plastic container 3 Tense screw cap 4 , guarantee.

When "firmly" screwing on the screw cap 4 , like in the 2 shown, during "tightening" an axial force between the lid of the screw cap 4 and the top of the neck 2 generated, as well as in the 2 represented a seal 9 preloaded and so a reliable seal between the screw cap 3 to the bottleneck 4 guaranteed.

This axial preload force generated during the "tightening" between the lid of the screw cap 4 and the top of the neck 2 causes, as a result of on the pressure side of the thread flanks over each thread of the external thread 1 distributed arrangement of double-wedge Zentrierrastsegmenten invention 5 with stopper edges 6 in that the already described penetration of the wedge tips of the centering locking segments 5 in the area of the stopper flank 6 in the thread 7 the screw cap 4 in consequence of now additionally in the axial direction between the screw cap 4 and the neck part 2 the plastic container acting biasing force again significantly strengthened, so that in particular during transport of the plastic container, the inventive solution ensures a very high security against rotation of the screw.

The screw caps 4 are preferably made of a polyolefin (polypropylene or polyethylene).

This material is somewhat more flexible than the polyethylene terephthalate (PET) material commonly used at the bottleneck. Therefore, the thread can 7 the screw cap 4 , like in the 2 shown to be elastically deformed.

Thus, in addition to the non-positive threaded connection as a result of the arrangement according to the invention at the same time a positive connection between the thread 7 the screw cap 4 and the stopper flank 6 of Zentrierastsegmentes 5 ,

The arrangement according to the invention acts in conjunction with the screw cap 4 in the form of a "barb".

Will now when using the spray gun 2 turned against the "Zuschraubrichtung", this does not cause when applying the solution according to the invention that the screw cap 4 solves.

LIST OF REFERENCE NUMBERS

1

external thread

2

neck

3

Plastic containers

4

Screw type

5

Zentrierrastsegment

6

stopper edge

7

thread

8th

spray gun

9

poetry

H

wedge height

D

wedge thickness

Ho

Edge wedge height

do

Edge wedge thickness

H _G

Thread pitch

D _G

Thread thickness

Claims (3)

External thread (1) for the neck part (2) of plastic containers (3) on which screw caps (4) with an external thread (1) associated with internal thread (4) are arranged, characterized in that on the pressurized thread flank over each thread of the external thread ( 1) distributes a plurality of double wedge-shaped Zentrierrastsegmente (5) with stopper flanks (6) are arranged, wherein in Schraubrichtung the Schraubverschlusskappe (4) the double wedge Zentrierrastsegmente (5) are formed such that both their wedge thickness (D) against the pressure side of the external thread (1) , as well as their over the core diameter of the external thread (1) of the neck portion (2) protruding wedge height (H) increases up to the stopper edge (6) and there breaks off like a sawtooth. External thread (1) for the neck part (2) of plastic containers (3) according to Claim 1 , characterized in that the wedge height (H) in the region of the stopper flank (6), the flank wedge height (Ho), about 40% to 70% of the thread pitch (H _G ) of the external thread (1) over the thread core diameter of the neck portion (2) , External thread (1) for the neck part (2) of plastic containers (3) according to Claim 1 , characterized in that the wedge thickness (D) in the region of the stopper flank (6), the flank thickness (D ₀ ), about 60% to 100% of the thickness of a thread, the thread thickness (D _G ), the external thread (1) of the neck portion (2) is in the core diameter at the thread root.

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