EP0836576B2 - Spring-effect hinge arrangement, for example for one-piece injected plastic closures - Google Patents

Description

The present invention relates to a hinge according to the preamble of claim 1.

Various resilient hinges, such as are used in particular in one-piece injection molded plastic closures, are known from the prior art. A so-called snap effect should be brought about regularly with such hinges for plastic closures . A snap effect is understood to mean opening the hinge automatically after a certain forced initial deflection (dead center) of the hinge system and an analogous effect when closing, in that the hinge automatically returns to a closed position after a dead center has been exceeded. This effect is basically taken over by special spring elements. In connection with such snap effects , the snap force and the angle of action are characteristic quantities. The snap force is the resistance that the hinge system has to opening and closing. The angle of action is defined by the area which the hinge parts independently overcome due to the spring action and is thus determined by the area between the rest positions of the hinge parts.

The basic principle with the vast majority such hinges is a cover part around to pivot a defined main motion axis.

European patent EP 0 056 469 describes a hinge for a plastic closure, whose axis of rotation by a defined, the lid and main film hinge connecting the closure body is formed and clearly defined. The A snap effect is achieved by interacting with the side this main hinge arranged spring arms reached. The snap effect is based on one embodiment on the bend of U-shaped intermediate elements in other embodiments on one Bending wall areas of the closure parts, wherein usually the cap has a bend in the middle experiences. The snap effect also comes here caused by bending effects around the narrow side.

The from the patent specifications WO 92/13775 or EP 0 331 940 known hinge arrangements use primary bending effects in combination with one Main axis, around a spring action for a To achieve snap effect. The corresponding closures open because of the existing geometric Main axes essentially on a circular Train. In the constructions mentioned, with the closure closed, certain parts the outer contour of the closure.

U.S. Patent No. 5,148,912 describes one Hinge arrangement for a closure with a closure body and lid, with which the closure has the same circular cross section as the closure body itself. Lid and closure body are via two flexible, belt-like connecting arms that are trapezoidal, connected. These connecting arms are flexible and over Thin spots on the closure and on the closure body attached. The hinge-side film hinges the thin spots are arranged at an angle to one another. If you look at the closure from behind, so these film hinges are inevitably random arranged in the form of a V open at the bottom. The arrangement of the two lid-side film hinges is mirror-symmetrical. This hinge points not a good snap effect because there are no suitable ones Spring forces can be built up.

The known hinge arrangements have various disadvantages. With all known hinges with a major axis against which Tension straps or similar elements are staggered (joint axis offset), there is a need to this main axis for convex injection molding closures outside the closure outer contours to arrange. The above elements are however out technical and aesthetic reasons undesirable. Another disadvantage is that the snap effect because of the difficult mechanical influences is unpredictable and regular to one insufficient snap effect or too impermissible Material stresses leads. Another disadvantage is the fact that conventional hinge arrangements only unpredictable and insufficient angles of action enable that often only at about 100 ° lie. It is because of the well known principles unpredictable mode of action particularly disadvantageous, that for a design-wished, new locking geometry each complex prototype series must be made to a technically to achieve satisfactory closure kinematics. The one with conventional closures Main hinge means that the locking parts in the Spray condition must be very close to each other. The corresponding injection mold therefore has the Disadvantage that the wall thicknesses in this area, due to the inevitable connection between the Closure bodies must be made very thin. The subsequent cooling and wear problems, have a negative effect on the cycle time and the service life of the injection mold.

Another limitation of such known ones Hinge arrangements, which are made in one piece from plastic can be injected is that only systems can be achieved with a maximum of one snap effect can. In other words, for the opening process of the closure beyond a maximum of one Dead center reached a maximum of two rest positions. These rest positions are essentially the open and the closed Condition of the closure. Because of the regular occurring plastic deformations falls the open rest position is not with the position in the injection molding state together.

The mechanical effects that work such closures are based on essential spiral spring effects. The energy that needs is used to deform a bending element by means of bending, determines the snap force of the hinge. Becomes an element of a bend relevant to this effect the corresponding bending deformations are exposed these elements are large compared to it characteristic sizes (e.g. thickness of a bending plate) or the spiral springs have in the unloaded Condition a considerable spatial expansion. at very small closures or with special closure geometries (small radii of curvature in the area of the hinge) the necessary functional elements of conventional hinge arrangements, like main hinge and straps, not Realize more or lead to insufficient Snap effects or impermissible material stress. Another limitation is that that the closures in the area of the hinge are necessarily have a convex outer contour have to.

Observed in various existing ones Plastic closures the flow of power, so you put here considerable variations with the same closure types firmly. Many places have thin spots (film hinges) Constructions impermissibly highly stressed. Is one Lock a fixed main axis of movement in The shape of a thin spot is sometimes large Squeezes in the functionally important elements, in particular recognizable in the film areas. Hinge parts, which, for example, is fixed via a main film hinge are interconnected, form in the open state still a relatively rigid unit. Will that Lock a relative movement when the hinge is open along the main hinge opposite the Main containers can be forced through this Rigid connection between the lid and the main container in the functionally important hinge elements be initiated, which will destroy the closure to lead.

The track that the hinge parts open or closing is described relative to each other with all these conventional hinge principles in essentially a circular path through the Main film hinge is specified exactly. Are requirements to the relative movement of the hinge parts when opened, these can be of such constructions not be covered.

Many materials (including sprayable plastics) show unfavorable behavior if they are used for a long time exposed to stress. This Creep and aging effects have a negative impact on the How a closure works. It works therefore disadvantageous from that the known hinge arrangements do not take this into account and often considerable residual tensions in the rest positions exhibit.

It is therefore an object of the present invention to create a hinge which at largely predictable, good snap forces and large possible angles of action, if desired also over 180 °, avoiding excessive material loads a defined but variable relative movement the locking parts to each other around a virtual Axis of movement and, if desired, several stable ones Allows rest positions. It is also the job of Invention to create a hinge, which also small and complicated, especially concave Closure geometries, can be used and largely within the closure contour can be arranged. In particular, the optimal Design of the injection mold to be possible on the one hand shorten the cycle time during production and on the other hand the service life of the injection mold increase.

This object is achieved by the in the claims specified invention solved.

A certain mutual movement curve the hinge parts are advantageous, for example, when an obstacle area has to be overcome. But the movement path also has a meaning when the two hinge parts functionally interact Contain elements. In the range of For example, plastic closures, it is essential that the pouring spout with its sealing counterpart meet at a favorable angle to achieve an optimal seal.

The invention enables a hinge system which has two or more essentially tension-free rest positions and intermediate dead points during the opening and closing process. The states beyond the dead centers are predetermined and controlled. You can achieve several snap effects with different snap forces in one opening and closing process, based on the constructive concentration of functional hinge elements for the targeted use of quasi-stable conditions. The functional, mechanical effects are no longer bending effects around the narrow side, but coordinated pulling and pushing effects with their possible secondary appearances. If functionally important elements of the present invention are subjected to bending, this is only secondary. Such bending deformations are prevented as far as possible by appropriate technical measures (e.g. rigid design of the pressure element concerned).

The hinge type according to the invention draws further characterized by the fact that z. B. with sprayed one-piece plastic closures none protrude disruptive parts from the closure contour.

The idea of the invention aims at the necessary design and concentrate functional elements that an essentially predictable Kinematics of the closure is achieved while ensuring that the end positions and the intermediate resting positions of the closure largely are tension-free.

The snap effect and especially the According to the invention, the snap force is exclusive through the concentrated, between the hinge parts lying, functional elements. cover and closure body of a plastic closure can with freely definable stiffness and largely any geometry.

Since the hinge parts are not firmly connected to one another via a main hinge in the main movement axis, the result is that unintentional relative movements of the hinge parts, for example torsions transverse to the pivoting movement, do not damage the hinge. The invention has no fixed main motion axis. At any point in the movement process, only a momentary, non-fixed pivot axis can be determined, which can also be skewed at times. This virtual axis, which moves during the movement process, is not physically present and does not coincide with a structural part of the hinge. Nevertheless, the cover parts move on the intended path and reliably reach the end position intended for them. The position and movement of this virtual axis and thus the relative movement of the hinge parts are significantly influenced and controlled via the geometric structure of the hinge mechanism. More degrees of freedom are made possible and a total angle of effect of more than 180 ° with - if desired - several snap effects can be achieved. Special embodiments also allow an at least approximately complete integration of the functional elements into the outer contour of the closure, in particular in the case of plastic closures molded in one piece.

Figur 1

zeigt einen funktionalen, schematischen Aufbau einer Kippstufe 1 mit zwei Zwischengliedern 20, 21, zwei Druckelementen 2.1, 2.2, zwei Zugelementen 3.1, 3.2 sowie zwei Schubelementen 4.1 und 4.2:

Figur 2

zeigt ein Ausführungsbeispiel einer Kippstufe 1 in geschlossenem Zustand;

Figur 3

zeigt das Ausführungsbeispiel von Figur 2 im offenen Zustand;

Figur 4

zeigt schematisch die Bewegungskurve und drei Kippzustände eines Scharniers 25.1-25.3 mit zwei hintereinander geschalteten Kippstufen;

Figur 5

zeigt ein Anwendungsbeispiel einer Kippstufe gemäß Figuren 2 und 3 in einem einteilig gespritzten Kunststoffverschluß 25 bei geschlossenem Verschluß;

Figur 6

zeigt den Kunststoffverschluß gemäß Figur 5 in offenem Zustand;

Figur 7

zeigt eine Kippstufe 1 mit zwei über eine Dünnstelle 11 verbundenen Druckelementen 2.1, 2.2 in geschlossenem Zustand;

Figur 8

zeigt schematisch die Wirkungsweise eines besonderen Ausführungsbeispiels mit einem Gesamtwirkungswinkel von 180°;

Figur 9

zeigt schematisch ein Verbindungselement 5 mit dargestelltem Zwängungswinkel k;

Figur 10

zeigt eine schematische Darstellung eines Kippvorganges mit seinen Winkelzusammenhängen;

Figur 11

zeigt ein Diagramm zur erfindungsgemäßen Optimierung der Geometrien;

Figur 12

zeigt ein Ausführungsbeispiel mit zwei hintereinander geschalteten Kippstufen 1.1, 1.2 in geschlossenem Zustand;

Figur 13

zeigt das Beispiel von Figur 12 in einem teiloffenen Zustand bei geöffneter, erster Kippstufe 1.1;

Figur 14

zeigt das Beispiel gemäß Figur 12 und Figur 13 im vollständig offenen Zustand mit geöffneten Kippstufen 1.1, 1.2.

The functional principle and exemplary embodiments of the invention are explained in more detail with reference to the figures and diagrams listed below.

Figure 1

shows a functional, schematic structure of a tilting stage 1 with two intermediate links 20, 21, two pressure elements 2.1, 2.2, two tension elements 3.1, 3.2 and two thrust elements 4.1 and 4.2:

Figure 2

shows an embodiment of a flip-flop 1 in the closed state;

Figure 3

shows the embodiment of Figure 2 in the open state;

Figure 4

schematically shows the movement curve and three tilting states of a hinge 25.1-25.3 with two tilting stages connected in series;

Figure 5

shows an application example of a flip-flop according to Figures 2 and 3 in a one-piece injection molded plastic closure 25 with the closure closed;

Figure 6

shows the plastic closure according to Figure 5 in the open state;

Figure 7

shows a flip-flop 1 with two pressure elements 2.1, 2.2 connected via a thin point 11 in the closed state;

Figure 8

shows schematically the operation of a particular embodiment with a total angle of effect of 180 °;

Figure 9

schematically shows a connecting element 5 with a shown angle of constraint k;

Figure 10

shows a schematic representation of a tilting process with its angular relationships;

Figure 11

shows a diagram for optimizing the geometries according to the invention;

Figure 12

shows an embodiment with two successive flip-flops 1.1, 1.2 in the closed state;

Figure 13

shows the example of Figure 12 in a partially open state with the first flip-flop 1.1 open;

Figure 14

shows the example of Figure 12 and Figure 13 in the fully open state with the flip-flops 1.1, 1.2 open.

The invention is explained in more detail below with the aid of examples of one-piece injection-molded plastic snap closures. However, the invention is not restricted to such plastic parts. The hinge according to the invention, which articulates at least two hinge parts, consists of one or more tilting steps, each of which is bordered by rigid intermediate members or the hinge parts themselves. A single tilting step has the purpose of giving the hinge a certain partial snap force and partial angle (in relation to the total opening / closing movement) and is responsible for a snap effect. If several tilt levels are connected in series, the hinge receives the same number of snap effects as tilt levels. When opening or closing, the hinge passes as many dead centers as there are tilting stages connected in series. Each flip-flop thus carries a certain proportion of the total angle of effect. The corresponding partial angle can assume a certain desired size through a corresponding geometric arrangement of the functionally important elements of a tilting step. A relationship between the partial angle of a tilting step and the geometric arrangement exists and is used in a targeted manner.

Figure 1 shows a schematic representation the functional elements of a flip-flop 1 in the closed Status. The flip-flop contains two pressure elements 2.1, 2.2, which are articulated, e.g. via film hinges, connected with two intermediate links 20, 21 are. Two tension elements 3.1 and 3.2 are parallel to arranged these pressure elements. Between Pressure elements 2.1, 2.2 and the two tension elements 3.1, 3.2 two thrust elements 4.1 and 4.2 are arranged. The flip-flop thus has two functional groups, namely two connecting elements 5.1, 5.2, which in turn one push element 2, one pull element 3 and contain a thrust element 4. The functionally important ones Elements are articulated with the stiff pontics 20 and 21 connected. This flexibility can with plastic injection molded lids with the help of thin points or analogous arrangements can be achieved. The intermediate links 20 and 21 limit the here Tilt level 1 or the tilt level is directly with here Hinge parts not shown directly connected.

To go from closed to open to reach a tilt level 1, they have to be stiff Intermediate links 20, 21 are moved against each other that the intermediate link 20 is a momentary Axis of rotation, which here is approximately parallel to the Connection line between the centers of the two pressure elements lies and not during the closing process is stationary, moved backwards. The force applied in the process must describe the snap force the tilt level 1. Such a force naturally occurs when Open the hinge containing the tilting step. The force required changes until the Dead center of the flip-flop. If this force increases, tensions also increase in the functionally important Elements. The tension elements 3.1, 3.2 are more and more on train and the pressure elements 2.1, 2.2 more and more under pressure. Are these burdens in a permissible for the material used Area, shorten or lengthen the corresponding Reversible elements. It gets energy in saved these items. The pressure and tension elements act as compression springs or as elastic Spring elements and cause the spring effect per connecting element. If the critical dead center is reached, the flip-flop jumps into the open one without further action Position.

The proportion and arrangement of the pressure 2.1, 2.2 and tension elements 3.1, 3.2 are determined in such a way that optimized angles of action and snap forces occur. It is essential that the required in the pressure element Pressure forces initiated and without buckling can be included. This is the thickness of the Pressure elements in relation to the thickness of the tension elements to consider. Insufficient thickness of the printing elements leads to unfavorable snap behavior. In the Figure 1 entered by dashed lines the end points of the pressure and tension element of a connecting element 5.1, 5.2 make an angle  one, which will be explained further below, according to the invention to achieve the desired partial angle Flip-flop is used. Furthermore is to be achieved an optimal snap force by two normal to each by the pressure elements 2.1, 2.2 and the tensile elements 3.1, 3.2 spanned planes standing Vectors 30 and 31 in the end positions of the Closure included wrap angle significant. In the constructive implementation of the Invention is to ensure that the in a pressure element, z. B. caused by eccentric pressing Bending stresses, by suitable technical Measures are prevented from the pressure element to cause it to buckle.

When looking at conventional hinge systems for plastic closures, one can see that closures of different shapes or designs, even if they are based on the same principle, have very different snap effects and different snap forces. Certain versions of these closures even completely miss a snap effect, although this is an explicit target of corresponding patent specifications. The reason for this lies in the complex mechanical processes on which such hinges are based, or in the fact that the hinge parts themselves make a significant contribution to the functioning of the closure and thus, even with slight changes in geometry, effects which are not easy or unforeseeable occur. These disadvantages are remedied by the present invention in that the functionally essential elements are reduced to a minimum and are concentrated locally and in their spatial extent, but at the same time allowing more flexible movement sequences compared to conventional hinge principles. This is especially true in contrast to snap locks with fixed main axes of movement, which always describe a rotational movement with a spatially fixed axis of rotation relative to one another.

The operating principle of flip-flop 1 is based on the presence of one or more pressurized Pressure elements 2.1, 2.2 which in active combination to suitably arranged tensile loads Tension elements 3.1, 3.2 stand. By pushing and pulling elements in their spatial extension and dimensioning are coordinated, is achieved that pressure and tensile forces are specifically introduced. With unwanted movements, it is unavoidable that secondary pressure loads on the Tensile element act. These are undesirable forces but much smaller than those that occur in normal operation Tensile loads and are in terms of intended function of the hinge negligible. The same applies to the printing elements. To the hinge mechanism to protect against shearing and to prevent improper Preventing movements is pro Tilt level 1 at least one thrust element 4.1, 4.2 is provided. It can be used, for example, with plastic injection molded parts as a thin, rigid membrane or Be formed thin. This thrust element 4.1, 4.2 is essential for the invention, by preventing unwanted movements and the locking parts around their virtual movement axis coordinated. The thrust element can be as in Figure 1 each a pull with a pressure element directly connect, or provided elsewhere become. The resilience and the total angle of action, hence the snap effect of a flip-flop according to the invention essentially only with the help of compression and tension elements and not by bending springs reached.

A preferred embodiment of a flip-flop is shown in Figure 2 and Figure 3. The two Figures show the tilt stage 1 once in the closed State (Figure 2) and in the open state (Figure 3). It contains two printing elements 2.1 and 2.2 and two Tension elements 3.1 and 3.2. The corresponding thrust elements 4.1, 4.2, which the necessary interaction guarantee the pressure and tension elements, are formed here by rigid shear membranes in this embodiment for optical reasons, especially if the hinge is injection molded is made of plastic, as a thin, continuous Membrane are formed. The resulting essentially trapezoidal elements have a pronounced stiffened pressure side and one pronounced, relatively thin elastic side of the tension. The flip-flop 1 then consists of two connecting elements 5.1, 5.2, which by thin spots 10 with the stiff pontics adjacent to the flip-flop 20.1, 21.1 are connected. The strain on the Thin spots 10 can be formed by suitable geometry or Pressure or tensile stiffness of the essential elements be kept within a permissible range. excessive Forces can go through in certain areas plastic deformation of a permissible part of the Thin spots are reduced. The printing elements 2 are constructed in such a way that they are not under the can buckle normal loads. In Figure 3 is clearly visible, like the flip-flop around the thin areas 10 is moved and to rest in its open position comes. Both those in FIG. 2 and in FIG. 3 positions shown are all elements of the flip-flop essentially free of tension. During the tipping process are basically neither bending effects in the Intermediate links 20.1,21.2 still in the connecting elements 5.1, 5.2 required. A bend or Buckling of the connecting elements does not occur.

A possible relative movement of the hinge parts 23, 24 of a hinge 25.1 is shown schematically in FIG. 4. The hinge parts 23, 24 are connected here via two tilting stages connected in series. The first flip-flop is made up of intermediate links 20, 21 and connecting elements 5.2. The second flip-flop is made up of links 21, 22 and connecting elements 5.1. Figure 4 shows three states of tilt of the hinge. The hinge is shown in the closed state 25.1, in the first tilting state 25.2, ie with the first tilting stage open, and finally in the open state 25.3, in which both tilting stages are open. The opening path of the hinge is illustrated by the spatial curve or arrow 32. This opening path 32 can be significantly influenced by the arrangement and design of the partial tilt stages. It can be seen in FIG. 4 that the opening path shown deviates greatly from conventional, circular opening paths, which were imposed in particular on hinges with a fixed main axis of movement. In contrast to other known hinges without a main axis, there is nevertheless a defined movement path. The first flip-flop, which is formed from the connecting elements 5.2 and from the intermediate members 20, 21, has either a smaller snap force or the same snap force as the second flip-flop consisting of the connecting elements 5.2 and the intermediate members 21, 22, but then has one geometrically determined earlier snap effect. When the hinge is opened, the first tilting step jumps to its open state first. All three tilting states shown in FIG. 4 are essentially stress-free by using the relationships according to the invention to be explained below.

An application is now shown in FIGS. 5 and 6 such a flip-flop for a one-piece sprayable Plastic snap lock 25 shown. The closure 25 contains two hinge parts, namely the closure body 24 and a corresponding cover 23. A filler opening 16 on the closure body 24 is also intended a counterpart 16 of the cover 23 cooperate. The hinge parts are through a locking level 15 separately. The clasp has only one Tilt level, which connecting elements 5.3 and 5.4 contains. The connecting elements 5.3, 5.4 are over Thin spots 10 with the cover 23 or with the closure body 24 connected. Since there is only one Flip-flop exists, are those described above Intermediate links through the cover 23 or the closure body 24 replaced itself. The geometry of this The flip-flop enables a total angle of effect of over 180 ° and thus an opening angle from here approx. 200 ° so that the lock is in the open position (Fig 6) inclined downwards relative to the closure plane and the fill opening 16 is fully accessible makes. Is the closure ideally designed so that no or only minimal plastic deformations in the When the lock is pressed, the opening angle is (Position during injection molding) and the angle of action equal to the flip level. A bevel 18 allows it without major tool effort to manufacture the plastic cover so that the mentioned Open position can be achieved without the Interfering with the outer walls of the locking parts. Of course it is possible to find a corresponding one Lock also in a 180 ° open position to inject if this is for technical reasons is desired. The connecting elements 5.3 and 5.4 each consist of the very rigid Pressure elements 2.3, 2.4, the tension elements 3.3, 3.4 and intermediate shear membranes 4.3, 4.4. The outside of the connecting elements 5.3, 5.4 is just designed and optimally divided into the outer contour of the closed plastic cover. The Cross section of the plastic cover in Fig. 4 and 5 is for the application of the flip-flop shown here optimal, because straight thin spots 10 and optimal wrap angle can be realized. This kind of a flip-flop can also be used with other closure geometries combine. It is quite possible circular Cross sections, or other than described here Cross sections to use or slightly curved Thin spots 10 or other joint means in their place provided. To ensure a good snap effect, the thin spots are as ideal as possible Train joint axes. Of course you can but also corresponding, functionally equivalent Measures are taken. With curved outer contours can the fasteners accordingly be shaped. A particular advantage of the invention is that the connecting elements 5.3, 5.4 basically free of the position of the locking plane can be arranged. It is possible, for example, this in the vertical direction against the closure body 24 to move and fully integrate into it, what great freedom with regard to the closure geometries and allows design options. From the Figures 5 and 6 can be clearly seen that in the closed Condition the tilt level perpendicular to the hinge parts or to the locking level and here directly into the rigid closure body 24 or cover 23 transforms.

Another preferred exemplary embodiment of a flip-flop 1 is shown in FIG. This tilting stage contains two pressure elements 2.1, 2.2 and two tension elements 3.1, 3.2, which are each arranged parallel to one another. The flexurally rigid pressure elements 2.1, 2.2 are located directly next to a hinge center plane and are connected to one another via a thin point 11. This middle plane does not necessarily have to coincide with the symmetry plane. In this preferred embodiment, a pulling element 3 can be connected to a pushing element 2 by a thin shear-resistant membrane for aesthetic reasons. Of course, in this and in other embodiments, the wall thicknesses can be varied, it being necessary to ensure that the functions of a tilting step that are essential to the invention are retained. It is possible, for example, to design the push element 4.1 with a wall thickness corresponding to the wall thickness of the tension element 3.1, 3.2 or greater in some areas, as long as the functional tensile elasticity of the tension element 3.1, 3.2 remains guaranteed. The connecting elements 5.1, 5.2 here are directly connected to one another via the thin point 11 and each have a pronounced, stiffened pressure side and a relatively thin, elastic tension side.

Based on the following figures 8-11, the inventive concept in its broad meaning being represented. The mode of action is based on a Special case of a flip-flop explained in more detail. Basically, the geometry angle can be selected by a special choice and lengths of the partial angles, the snap force and the material load of a flip-flop can be varied. It should be emphasized here again that each flip-flop basically only a partial angle of entire hinge movement recorded. In the following described, simplest case of a single flip-flop However, the partial angle of the flip-flop corresponds to that Overall working angle. The necessary relationships are explained below.

Figure 8 schematically shows an embodiment with only one level, only part of which is shown here a connecting element 5 is shown. The flip-flop is characterized here by two planes of symmetry 40, 41 out. These planes of symmetry 40, 41 generally remain preserved in every opening position of the hinge. This version has a (theoretical) angle of action from 180 ° to. It will go on from there assumed that under a position with an opening angle from 0 ° the drawn closed state and an opening angle under an open position of 180 ° is understood. When explaining the How this particular embodiment works is related to the two planes of symmetry mentioned taken. This approach enables that Explain the function based on a sub-problem. The For the sake of simplicity, one push and one pull element as lying in one plane and as geometrical Unity. The following parameters are from importance of the invention. On the one hand the angle  between two thin places assumed here Pontic or by the endpoints of the Pressure and tension elements defined lines included Angle. The wrap angle ω is the An angle that can be seen from a top view of the hinge between the levels of the intermediate links in a closed Position (see Figure 1, arrows 30, 31). Provided the intermediate links 5 in other embodiments are not perpendicular to the hinge parts or Pressure elements 2 and tension elements 3 are not parallel to each other are the determination of the Angle ω accordingly. In the present, parallel arrangement of the push and pull elements are those spanned by the pressure elements Level and that spanned by the tension elements Level (not shown in Figure 8) accordingly spaced from each other. Both angles largely determine the constraint (and thus the snap force) on the pontics and Opening angle. The planes of symmetry are in FIG. 8 shown. The plane of symmetry 40 is during that entire stationary sequence of symmetry the flip-flop. It generally forms the plane of symmetry between the connecting elements 5.

The plane of symmetry 41 is movable and forms the second plane of symmetry in every state of motion. It forms the plane of symmetry of each Connecting element 5 to itself. From Figure 8 is their position in the closed position 41.1 and in the open position 41.2 of the flip-flop.

Due to the symmetry conditions, the Functionality considered using a partial model, which is a quarter of the flip-flop. This Partial model is shown in Figure 8. It shows half of one Intermediate member 21 and part of a connecting element 5. The model shown describes approximately the mechanical processes of the flip-flop. The connections and the resulting constraint, which the snap force is modeled below shown. The material is constrained forced deformation understood which one elastic (reversible) state of tension. The material resists the forced one elastic deformation, on which the snap effect is based. According to the invention, specific train and Pressure zones formed. The designated as pressure zones Areas are formed so that a buckling is prevented from their level. The as train zones designated areas can be in length and Thickness can be varied so that, due to the geometry, forced stretch the material load within the elastic (reversible) material behavior remains. With regard to the plane of symmetry 41 ensures symmetrical design of the flip-flop a good snap force by adding a double hinge effect is avoided within the flip-flop.

It is assumed that for the model presentation the thin points that act as hinges 10 can be considered as ideal hinges. Under a ideal hinge is understood to be a hinge which has no internal friction and no stretching in the hinge parts themselves. So it will be off assumed that the rotational movement of all points happens smoothly around a fixed axis 10. As Intermediate members 21 parts are considered not deformable provided. Each of the fasteners 5 is considered one in its level in the train area stretchable element considered. The fasteners 5 always stay in one plane, so that a bend considered as not permitted from this level becomes.

The reference numbers * .1 each refer to Elements in the closed position, those with * .2 on Items in the open state. The reason for the squeeze can best be understood if a point P is viewed in space. This point P is on the Line of symmetry 43 of the intermediate links 5 and in the movable Level of symmetry 41. Its position is dependent from the opening angle of the flip-flop. The position of P on the line of symmetry plays for these considerations no relevant meaning. P would, due to the hinge condition to which it is subject the circular path k1 move with the center at point A and the hinge axis 10 as the axis of rotation. Due to the invention forced symmetry conditions the flip-flop, however, point P becomes a curve This forced the model to be a circle with a center is approximated in B.

A straight line e2 between the stationary Point B and the moving point on K2, which is the Not shown in Figure 8 for clarity was (see FIG. 9), forms the Tilt level in its point lying on water the surface normal to level 41. This straight line e2 moves together with the connecting element 5. A straight line e1, between the stationary points B and the moving point on k1, would describe line e2, if this is not subject to any constraint would. In Figure 8 is also half the wrap angle ω / 2 and the angle  / 2, which are significant influence the snap effect, clearly recognizable.

Figure 9 shows schematically the constraint state of half the connecting element 5. With the reference number 43.3 is the position of the line of symmetry 43 as a result of coercion. They are also lines Pressure and tension areas 2, 3 of the connecting element 5 shown. The constructive location of point P to determine the angle κ must of course not necessarily in the middle of the section shown here the line of symmetry 43. The situation, however, is depending on the material thickness selected Pressure and tension areas 2, 3 and is determined by the Neutral point on line 43. Below The neutral point is understood here as the point in which the stresses along the straight line 43 in Are balance.

Figure 10 now shows a schematic partial representation the relationships of a flip-flop with one Opening angle γ less than 180 °. The opening angle γ of a flip-flop can meet the requirements to get voted. To in closed and in the open position of a flip-flop according to the invention to achieve two stress-free states the relationship described below is fulfilled his. These relationships according to the invention are also at an opening angle γ of more than Purpose 180 °. In addition to what is only partially shown here Intermediate member 21 is half of a connecting element 5 in closed 5.1 and in open Position 5.2 shown. The intermediate member 21 and that Connecting elements are via a hinge axis 10 connected.

For two tension-free states of the flip-flop, the relationship between the opening angle γ of a flip-flop, the wrap angle ω and the angle  of the connecting elements is defined by the following formula:  = 2 * arctan [ Sin (γ / 2) 1-cos (γ / 2) * Sin (ω / 2)]

FIG. 11 shows a typical course of the constraint angle κ of a flip-flop as a function of the angle ω and the opening angle γ of a flip-flop. It is assumed that an angle  is selected, which to the stress-free according to the invention End positions. As already shown κ means a measure of the constraint of the material. Given the wrap angle ω is in the points with horizontal tangent the maximum Squeezing the material and the dead center of the snap force given. The dead center lies in half the opening angle γ of the flip-flop.

Figures 12-14 show a hinge with two flip-flops 1.1, 1.2 with stiff pontics 20, 21 and 22, and two hinge parts 23, 24. Of course the flip-flops can also go directly into the Skip hinge parts. The tilt levels are schematic drawn and correspond for example the flip-flops as described with reference to Figures 2 and 3 were. The hinge is shown in FIG shown closed state. Jumps the flip-flop 1.1 in its open state, then corresponds to first theoretically stress-free tipping state of the Hinge the state shown in Figure 13. at no external forces act in this tilted state on the hinge. The flip-flop 1.1 is fully open and flip-flop 1.2 is still fully closed. The hinge shown in Figure 13 has a first Partial snap effect already effected. If you open that Hinge further, so you reach another dead center and the hinge jumps into another one essential stress-free tilting state, accordingly Figure 14. In the one shown in Figures 12-14 Hinge this is the fully open tilt condition. The opening angle of the schematically drawn Hinge is much more than 180 °.

The invention preferred, in particular one-piece molded hinge parts, a total angle of effect of 180 ° to provide the tool shop to simplify. From manufacturing technology Geometries of the tilt levels are to be preferred for reasons which such as those shown in Figures 2, 3, 7 Exemplary embodiments, as few articulation points as possible exhibit. A particular advantage of the invention is also the fact that with low and maintenance-friendly, tooling effort thanks to the Concentration of the functional elements under extensive Avoiding slits or recesses for closures, especially on the hinge adjacent areas, a good seal is brought about can be. The seal may be preferred under further avoidance of recesses, through measures such as those in the international patent application PCT / EP 95/00651 are provided, be made. In special embodiments can also the described train and Printing elements not parallel, but at an angle be arranged to each other. For elongated hinge parts can also have two or more tilt levels next to each other to be ordered. The individual side by side arranged elements of the flip-flops can have no connection with each other or, if desired, by means of an unimportant function Membrane connected. It is therefore conceivable to have several Combine tilting stages in their mode of action, for example to enhance the snap effect to effect.

Claims (10)

1. Resilient hinge arrangement without a principal hinge which comprises at least two hinge parts and connecting arms which connect said hinge parts, characterized by one or a plurality of series connected tilting units (1) each comprising at least two connecting elements (5), each of which comprises a flexurally rigid pressure element (2) and a tensionally elastic tension element (3), each of which is attached, via a hinged connection, either to rigid intermediate members (20) or directly with rigid areas of the hinge parts (24, 25), and is arranged to be at least substantially rigid under shear loads by means of at least one associated shear element (4).
2. Hinge arrangement according to claim 1, characterized in that the intermediate members (20) and the tilting units (1) are substantially stress-free not only in the open position but also in the closed position.
3. Hinge arrangement according to claim 1 or claim 2, characterized in that the pressure (2) and the tension elements (3) of a tilting unit (1) are arranged parallel with respect to each other, and the planes defined by the pressure elements (2) and by the tension elements (3) are spaced away from each other.
4. Hinge arrangement according to one of claims 2 to 3, characterized in that the connecting elements are arranged in pairs (5), the connecting elements of which are pivotingly interconnected via a hinge axis (11) which is disposed parallel with respect to a principal movement plane.
5. Hinge arrangement according to one of the preceding claims, characterized in that the angle Φ, which is encompassed by the lines defined by the end points of the pressure elements (2) and the tension elements (3) has a value which complies with the following formula

   

   wherein

   

   , in a plan view of the hinge, is the projected angle between two normal lines on to the planes defined by, in each case, one pressure (2) and tension element (3) and γ is the opening angle of tilting unit.
6. Hinge arrangement according to one of the preceding claims, characterized in that the pressure elements (2) and the tension elements (3) are arranged relative to each other such that, in each opening position, a plane (41) of symmetry, which is moving and is disposed perpendicularly relative to the principal movement plane, forms the plane of symmetry for the pressure elements (2) and tension elements (3) with respect to themselves.
7. Hinge arrangement according to one of the preceding claims, characterized in that the shear element (4) is designed to be a membrane which is rigid under shear loads and which connects the pressure (2) and the tension element (3) along their entire length.
8. Hinge arrangement according to one of the preceding claims, characterized in that a plurality of tilting units (1) are interconnected such that the hinge arrangement has a number of stress-free states which corresponds to the number of its tilting units, and in that dead centres are disposed between two such states, respectively, and in that the hinge arrangement, beyond each such dead centre, automatically and resiliently assumes the next adjacent stress-free state.
9. Hinge arrangement according to one of the preceding claims, characterized in that the shear element is connected to the pressure element (2) and the tension element (3) and has the same wall thickness as the tension element (3).
10. Use of a hinge arrangement according to one of the preceding claims for a one-piece injection-moulded plastics closing means.

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