EP0951427B1 - Sealing clip for bags and tubes, and matrix for sealing the latter - Google Patents

Description

The invention relates to a wire section of round cross section existing closure clip for bags, film tubes or the like, with a Pre-bent bracket base and two adjoining it on both sides Brace legs, which in the closed state like a helix around a braid gathered bags, film tube or the like. are bent and lie partially next to each other. The invention further relates to a wire section for the Locking clip and on a die with two sliding grooves for Close the locking clip.

Simple locking clips consisting of a round wire section can can be produced in that an endless wire of a sealing machine a section of the wire is cut off in the sealing machine and the wire section finally, for example, around one to be closed Bag braid is bent around. It is also known a capping machine not endless wire, but already feeding separate wire sections that A circular cross-section of the same diameter over its entire length to have. The wire sections can be preformed straight or U-shaped; the former is known from DE-A-41 20 440, the latter from CH-A-447 109. For These wire sections are usually placed next to one another in a magazine Carrier tape attached so that they form a magazine strand (DE-A-41 20 440).

The advantage of such closure clips formed from a wire section lies in their simple manufacture. The tightness of closures that can be achieved thereby against it left something to be desired.

Serve as a tool for closing the locking clips mentioned usually capping machines that have a stamp and a die. The U-shaped pre-bent locking clip is first from a magazine from adopted the stamp and guided against rotation. Then be Stamp and die moved towards each other. During this movement, the Clasp the packaging material gathered into a braid. Then the free ends of the legs of the locking clip reach the die first and are guided by sliding grooves in the die as the movement continues. The legs of the locking clip are plastically deformed so that finally a more or less circular closed closing clip results.

Are known - e.g. from CH-A-447 109 - matrices, which two in parallel have semicircular sliding grooves arranged with respect to one another. The main level of the Both slide grooves are somewhat opposite the main plane of the locking clip inclined so that each slide groove has an entry point that is in the main plane of the Locking clip is located. The main level is the level in which the center line of a slide groove or the locking clip runs. Will the Closing clip guided by a stamp for closing against the die moves, each of the free leg ends enters at a respective entry point one of the sliding grooves and one of these on one by the inclination of the Helix track caused by sliding grooves. This causes the two free ends of the Closure clip when closing past each other, so that it after the Overlap laterally and lie parallel to each other.

It is the object underlying this invention, one from a wire section to specify existing locking clip with a round cross section, with which can achieve closer closures than with the previously known Closure clips of this type.

The solution to this problem consists, according to the invention, in a closure clip genus mentioned above, which is characterized in that the two Brace legs extend from their staple bottom ends to their free ends steadily rejuvenate. This is based on the knowledge that there is a locking clip from a wire with a uniform cross-section when closing always in the area of the arch sections between the legs and the Bending the clamp floor particularly hard because this is where the bending stress is greatest is. Therefore take a uniform cross-section from a wire section existing closure clips never the ideal for tight closures Circular shape. Because of the tapering towards the leg ends Wire cross section of the closure clip according to the invention (which, for example is achieved by partially stretching the round wire) is the bending stress distributed much more evenly over the entire length of the legs, so that the locking clip when closing approximately the ideal circular shape assumes. In addition, each leg section is larger in the closed state and smaller diameter side by side, so that in this overlap section the total width of the closed bracket the diameter of the Output wire exceeds little and therefore no significant drop in the Surface pressure occurs.

Legs tapering towards the ends of closure clips for bag braids or the like are known per se from DE-A-37 15 626, but for brackets Band material, the thickness (with unchanged width) towards the leg ends decreases. When closing the leg ends are butted against each other and compressed, so that the closed bracket an almost closed Circular shape. Due to the tape thickness decreasing towards the leg ends is sufficient compression even with different cable cross-sections be achieved.

In a preferred embodiment of the closure clip, the clip base is preformed in a circular arc. The known from DE-A-37 15 626 Circular arch-shaped preforming of the clamp base supports the approach of the Closure clip to the ideal circular shape when closing.

Furthermore, a closure clip is preferred, which is on the outside Staple floor has an approach. With such an approach, the Locking clip must be guided in the stamp so that it cannot rotate.

The object underlying the invention is also solved in one Wire section for the closure clips according to the invention, which thereby characterized in that the wire section for the individual locking clip of the ends of the part forming the bracket base to both ends steadily rejuvenated. Such a wire section in particular solves the problem according to the invention in connection with such machines, which are straight, not pre-bent Wire sections are fed. in this case the individual wire sections first bent in a U-shape in the sealing machine (DE-A-41 20 440).

In the case of a straight wire section, it is particularly advantageous if the Cross section of the wire section for the individual locking clip from the center of the wire section decreases steadily towards its two free ends, so that the wire section already in the area of its later staple bottom to both Tapered sides. In this way, the wire section in the area of Even during preforming, the clamp base is subjected to even bending and therefore takes on an arcuate shape easily.

According to the invention, a die is also used to achieve the object mentioned type, whose two sliding grooves each start from one entry point narrow conically. Such a matrix has the advantage that the tapered clamp legs of the closure clip according to the invention Closing closer together than with conventional matrices. In addition, the die can be made narrower, so that only for the die a smaller space must be provided in the capping machine. With the Closed closure clips according to the invention claim on the packaging shirred together into a braid takes up less space, so less Packaging sleeve material is required for closing.

In a preferred embodiment of the die, the die is designed such that that the centers of curvature of the sliding grooves are mirror images of the Center of the recess offset and their parallel axes against the axis the recess are less inclined than the axis of one between the Ribs with sliding grooves. As a result, the tapered ends of the Clasp thighs when closing tightly against the braid Packaging sleeve as well as pressed together laterally.

Fig. 1

eine Verschlußklammer gemäß der Erfindung mit sich verjüngenden Schenkeln und rundem Querschnitt;

Fig. 2

eine Abwandlung der Verschlußklammer aus Fig. 1 mit einem kreisbogenförmigen Klammerboden mit Ansatz;

Fig. 3

einen Drahtabschnitt für die Verschlußklammern aus Fig. 1 und 2;

Fig. 4

eine Variante des Drahtabschnitts aus Fig. 3;

Fig. 5a bis c

verschiedene Ansichten bzw. Teilschnitte einer bekannten Matrize zum Verschließen der Verschlußklammern aus Fig. 1 und 2;

Fig. 6

eine geschlossene Verschlußklammer nach den Stand der Technik in Seitenansicht (und Draufsicht);

Fig. 7a und b

eine neue Matrize in Draufsicht und Teilschnitt;

Fig. 8

eine mit der Matrize aus Fig. 7 geschlossene Verschlußklammer mit sich verjüngenden Schenkeln.

Embodiments of the invention will now be explained with reference to the drawings. These show:

Fig. 1

a closure clip according to the invention with tapered legs and a round cross-section;

Fig. 2

a modification of the closure clip of Figure 1 with an arcuate clip base with approach.

Fig. 3

a wire section for the closure clips of Figures 1 and 2.

Fig. 4

a variant of the wire section of Fig. 3;

5a to c

different views or partial sections of a known die for closing the closure clips from FIGS. 1 and 2;

Fig. 6

a closed closure clip according to the prior art in side view (and top view);

7a and b

a new die in plan view and partial section;

Fig. 8

a closure clip with the die from FIG. 7 with tapered legs.

The variant of a closure clip 10 shown in FIG. 1 has a preformed one Clamp base 12 on which there is a leg 14 on both sides connects. Clip base 12 and leg 14 each have a round one Cross-section. This takes the legs 14 starting from their staple bottom Ends steadily towards their free ends. Ideally they form tapered leg 14 when closing the locking clip from Fig. 1 each a carrier of the same bending stress, so that they close when closed Round evenly.

It is intended to guide the leg ends when closing so that they slide past each other so that the free ends of the legs 14 after the Partially overlap the closure. Such a closed clip 10 is only slightly inclined to do so under the influence of the packaging material spring applied internal pressure. Also be Differing braid diameter compensated in that the The ends of the legs have different thicknesses after closing overlap. In this way, a large geometry can be achieved with a locking clip Range of different braid diameters can be covered. This simplifies storage, since only a few variants of the closure clip 10 must be kept in stock.

Fig. 2 shows a variant of the closure clip 10 of FIG. 1, in which the Clamp base 12 'is not flattened in the middle, but an arcuate shape Has. In addition, the clip base 12 'has an extension on its outer radius 16 equipped, which allows the locking clip 10 'when closing to guide exactly by the approach 16 in a corresponding groove of a Closing tool engages. This particularly prevents the Locking clip 10 'during closing.

In addition, Fig. 2 shows that the bracket base 12 'and the legs 14 'do not have a round cross section, but - with the exception of the area of the Approach 16 - a hexagonal.

Figures 3 and 4 each show a wire section 20 and 20 ', respectively Closure clips of the type shown in Fig. 1 or similarly shaped can. The wire section 20 from FIG. 3 has a cylindrical center piece the end sections 24 tapering on both sides towards the ends connect. The middle piece 22 is provided to be pre-shaped in a U-shape be, so that there is a staple bottom such as the closing clip 10 from Fig. 1 forms. Form the end portions 24 of the wire portion 20 then the legs 14 of the locking clip 10.

The wire section 20 can be preformed into the open closure clip 10 outside the sealing machine, for example at the closure clip manufacturer happen. The closure clip is then - possibly as part of a magazine strand - fed to the sealing machine in the preformed state.

The preforming of the closure clip 10 can also only within the Capping machine take place before the actual closing process. By doing the latter case, a wire section of the capping machine is stretched Condition fed. In this case, the wire section 20 'according to FIG. 4 particularly suitable. The wire section 20 'tapers starting from it Center steadily towards both ends. So it practically consists of only two conical end portions 24 '; a cylindrical center piece 22 as in the Wire section 20 is omitted. In this way, he already provides the later The central region of the wire section 20 'forming a clamp base 12 forms a carrier represents the same bending stress that is used for preforming in the sealing machine easily takes on a uniformly round shape. The staple legs 24 ' End regions of the wire section 20 'forming remain stretched. you will be only when closing the closing clip around the braid to be closed bent around. Since the clamp legs 24 'also make a carrier more uniform Represent bending stress, they also take the ideal when closing Circular arc shape.

Figures 5a to c show a known die 30 of a tool for Closing closure clips according to FIGS. 1 and 2. FIGS. 5b and 5c represent the cuts designated in Figure 5a.

The die 30 has a recess in the form of a part-cylindrical recess 32 on. In the wall 34 are two immediately adjacent, parallel mutually extending slide grooves 36 and 38 milled. Both slide grooves 36, 38 have the shape of an arc of the same radius, are also in cross section rounded and form a rib 35 between them. The centers of both Arcs also lie on a common central axis 40, which the Cylinder axis 42 of the recess 32 intersects. The central axis 40 is opposite the cylinder axis 42 so inclined (for example at an angle of 12 °) that the entry points 44 and 46 of the sliding grooves 36, 38, i.e. whose vertices are about in the central plane 48 of the die 30 running perpendicular to the cylinder axis 42 lie. The manufacture of both slide grooves 36, 38 is carried out in one piece Milling cutter about the point of intersection of the cylinder axis 42 with the central plane 48 defined vertical axis is pivoted about the aforementioned angle of inclination.

To close a closure clip 10, this is opened by a stamp the die 30 supplied. The free leg ends of the closing clip 10 get into the two sliding grooves 36, 38 and at the entry points 44, 46 are guided by the slide grooves 36, 38 during the further movement of the stamp. The clip legs 14 of the locking clip 10 are circular arcs bent and at the same time guided parallel to one another by the sliding grooves 36, 38, so that the closed closure clip according to the prior art the shape shown in Figure 6 with laterally overlapping, parallel to each other adjacent leg ends.

However, the die 30 from FIG. 5 would be used to close the locking clip 10 used in Fig. 1, the tapered staple ends would not brought so close together that they finally lie against each other laterally.

1 is therefore preferred for closing the closure clip 10 the die 30 'shown in FIG. 7 is used. The die 30 'also has two Slide grooves 36 'and 38', the main planes 37 ', 39' parallel to each other run, but compared to Fig. 5 - with unchanged inclination of the rib 35 '- are less inclined with respect to the central plane 48 '. At the same time they are Center points M2 and M3 and thus the - to the main planes 37 ', 39' vertical - axes of rotation 40 ', 40 "offset parallel to each other, namely mirror image on both sides to axis 40, which is at the same angle the axes of rotation 40 ', 40 ", which the rib 35' with the main planes 37 ', 39' includes.

This and the production of the sliding grooves 36 ', 38' with each other around the Distance M2-M3 offset single milling cutter does not change the fact that the entry points 44 'and 46' of the casting grooves 36 ', 38' lie in the central plane 48 '. The difference to the sliding grooves of the known dies (e.g. die 30 from Fig. 5) the sliding grooves 36 'and 38' starting from their entry points 44 'and 46' narrower so that the width of the slide grooves 36 'and 38' ideally corresponds to the respective width the tapered clamp leg 14 of the closure clip 10 corresponds. As a result, the clamp legs 14 become denser when they are closed merged and are laterally sealed when the closure clip 10 is closed to each other. This narrowing of the slide groove width from the entry point to the exit point (with which the 'pivoting back' of their main planes 37 ', 39' towards the central plane 48 ' corresponds) but has the consequence that the width of the die 30 '- transverse to Middle plane 48 '- can be significantly lower than that of the known die 30 (Fig. 5), which has the advantages described above. It is also advantageous that due to the geometry described above each slide groove to its outlet point shallow depth, with the further consequence that the legs 14 of the Closure clip 10 when closing more firmly against the one to be closed Packaging sleeve braid can be pressed.

One of many conceivable modifications of the matrices 30 and 30 'is To provide sliding grooves that do not run on a circular path, but on one Spiral track, so that the respective entry point of a sliding groove on a larger one Radius is the corresponding end point of the slide groove.

Through the described and other variations of the die, the shape of the closed locking clip adapted to a variety of uses become.

Fig. 8 shows a side view of the result of a closing process when one 4 is processed with a die according to FIG. 7.

Claims (7)

1. A sealing clip consisting of a wire section (20) of round cross-section for bags, film tubes or the like, comprising a pre-bent clip base (12) and two clip legs (14) adjoining the latter on both sides, which clip legs in the closed condition are helically bent around the bag gathered to form a neck, around the film tube or the like, and are partially lying one beside the other,
   characterized in that the two clip legs (14, 14') taper constantly from their clip base ends to their free ends.
2. The sealing clip as claimed in claim 1,
   characterized in that the preforming of the clip base (12) has the shape of a circular arc.
3. The sealing clip as claimed in any of the preceding claims, characterized in that on the outside of the clip obase (12') a projection (16) is provided.
4. A wire section for a sealing clip as claimed in claim 1,
   characterized in that the wire section (20, 20') for a sealing clip tapers constantly from the ends of the part forming the clip base to the two free ends.
5. The wire section for a sealing clip as claimed in claim 1, characterized in that the cross-section of the wire section (20') for a sealing clip decreases constantly from the middle of the wire section (20') to its two free ends.
6. A matrix for closing a sealing clip as claimed in claim 1, which has a substantially partly cylindrical recess (32) and in the same two parallel sliding grooves (36, 38) inclined with respect to the main plane of the clip base and curved corresponding to the recess, which sliding grooves each have an inlet point (44, 46) and an outlet point (45, 47), characterized in that the two sliding grooves (36', 38') taper conically from their respective inlet point (44', 46') to their respective outlet point (45', 47').
7. The matrix as claimed in claim 6, characterized in that the centers of curvature (M2, M3) of the sliding grooves (36', 38') are offset laterally reversed with respect to the center (M1) of the recess, and their parallel axes (40', 42") are inclined less with respect to the axis (42') of the recess (32') than with respect to the axis (40) of a rib (35') extending between the sliding grooves (36', 38').

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