Origin-protected container closure

DESCRIPTION

The invention concerns a closure of originality for a container with external thread elements and a radially directed outward flange that extends around the periphery and has a dome shaped shaped cap area, as well as a seal band of originality that is linked with the lower edge of the cap area by means of a series of frangible joining bridges spaced apart on the periphery, a radially directed inwardly retaining rib which can be disposed in an operative connection with the container flange is located on the inner surface of the original seal band, a series of originals being arranged on the original seal band projections directed upwards that axially request the superimposed cap part when the closure is seated on the container.

The closures with guarantee of originality, preferably made of plastics, are not new as such. Known executions (for example, U.S. Patent No. 4,432,461; U.S. Patent No. 3,329,295) usually has a bowl-like shape with a bottom thread that cooperates with a thread made on a container, and they usually have a band guaranteeing originality (hereinafter referred to as the originality band) or a ring of this kind that is mounted on the lower end edge of the lower part of the cap and which is connected with this part by means of a series of frangible joining bridges arranged in a circle. The originality band generally contains fixing elements in the form of ribs that are embedded under a flange radially directed outwards or with a flange located under the thread of the container. Thanks to this construction, the cap can be applied to the container in a known way by turning it to a threaded position in which the originality band expands so much that its inwardly directed rib slides over the surface of the bottle to mine there. flange or flange. Closures of this class are referred to below as "spring ring closures." When the cap is rotated to release it from the container, the rib and flange stumble against each other and, due to the blocking effect thus produced, cause the bridges to break, thereby making it possible to remove the cap part . The broken band is then left on the neck of the container to indicate that the cap has already been removed once and that the container seal has been broken. These closures were constituted in a very preponderant measure by plastic material, so that they can be molded in a usual casting process by pressing or by injection.

A drawback of the previously known and more described originality closures affects the metance of its application to the container. In the ideal case, when applying the originality band, it expands uniformly over the neck of the bottle or over the flange. In practice, this ideal case is not often achieved with known closures. Thus, it happens that the originality band is stretched upwardly around the lower part of the cap or else the fixations of the originality band in the lower part of the cap are torn off due to excessive lateral displacement (see Figures 16 and 19 ). As a result of this uneven deformation of the bridges, there is a risk that during the application a breakage of the bridges will occur or bridges that have been previously damaged during their removal will be broken too soon, so that the ring that must remain properly on the neck of the container, it is then removed from the side passing over the flange of the neck of the container. Slip on one side of the originality band also when applying the cap on the container. In this case, those nerves of the ring that hold the part of the originality band that has slipped on the flange of the container, are partly torn off, while those nerves of the ring that join the remaining part of the originality band with the Bottom of the cap, they are partially stressed. This last effect can also lead to a failure of the assembly of the cap, since by sliding on one side of the originality band the torque to be applied for assembly in the case free of defects is reduced. For this reason, there is a risk of erroinear control and clamping mandrel of the usually automated assembly equipment, whose mandrel reacts with great sensitivity to the torque, and that the cap is released before it has been completely arranged on the container.

A container closure with a guarantee of originality of the kind mentioned at the beginning is also known (see document EPA-52 804), in which the bridges connecting the originality band with the stain cap secured against excessive rotation of the originality band with respect to the cap in the first cap assembly on the thread of the container. In this previously known container closure, for example, on the front side of the originality band which is oriented towards the upper part of the cap, are provided some drag pins or projections that are each arranged in the arc of circle delimited by two contiguous bridges, at a short distance from one of the bridges and at a greater distance from the other bridge. When this previously known closure is seated on the container, these drag pins or projections directed upward towards the cap request the superimposed part of the cap, limit the movement of rotation of the originality band relative to the top of the cap when screwing this part on a container thread and therefore they would prevent premature breakage of the bridges when making the first assembly of this previously known container closure. However, in this previously known container closure, a non-uniform stretching of the originality band during the first assembly of the container closure cannot be safely excluded.

Likewise, it has been observed that in different previously known provisions the

018 The reciprocal action between the originality band and the flange of the bottle surface is not sufficient, when removing the cap, to achieve the desired separation and complete retention of the ring on the container. In order to achieve a more clean rupture of the ring during the first opening of the cap, the spring ring closure has been generally constructed so that the peripheral rotational forces exerted on the joint bridges when the cap is removed due to the locking action of the bottle flange, are greater than the concentrated tear force of these bridges. However, it is common that this "tear condition" is not achieved in the practic. This is especially in many cases due to the effect already described above that, when the cap is opened, the originality band is dragged on one side until it is beyond the rim of the container, thereby eliminating the effect of blocking the rim of the container . Therefore, anaologously to what happens when removing a new tire cover from a tire, making a withdrawal on one side reduces the torque required for this which causes the blocking effect. Thus, in many cases the tear condition for the union bridges or theoric break points cannot be achieved, so that, contrary to the designated objective of the originality band, this is removed from the container along with the cap.

Therefore, there is in particular the problem of creating an originality closure of the aforementioned class that avoids the aforementioned drawbacks of the previously known closures and that in particular guarantees a first securely free assembly and also a complete tear. and uniform of the bridges of union during the first opening.

This problem is solved according to the invention by the fact that the projections extend angled inwards, and the upper front edge area of ​​the lower part of the cap between the bridges, formed as a shoulder, is in operative connection with the truncated coonic lateral surfaces of the projections when the originality band and the lower part of the cap move axially towards each other. Thanks to the special configuration of the projections and the corresponding front edge area of ​​the lower part of the cap, non-uniform stretching of the originality band is prevented during the first assembly of the cap, premature breakage of the bridges and displacement side of the originality band. By means of the invention, the lateral displaceability of the original band is reduced considerably during the first assembly on the container. In this way, premature failure of bridges or uneven expansion of bridges is practically prevented. Therefore, an important cause is eliminated that can lead, during the first closing opening, to the originality band being dragged on one side and, therefore, the tearing condition is not reached. In addition, it is practically prevented that the joining bridges be stressed during the first assembly to the point that the originality band cannot slide on the flange of the container. These advantages are provided in particular by the projections according to the invention, which axially support the lower part of the cap with respect to the upper part thereof and also originate in a uniform seat of the retention rib on the flange of the container.

Including the characteristics of the improvements of the invention described in the dependent claims, they together result in improved mechanical properties of the closing arrangement, especially in the phase of increasing the load of the web during the first closing assembly on the container. . In particular, it is reduced in this case to the magnitude of the torque of twisting that is necessary to overcome the thickening or flange of the container. Therefore, the risk of damage to union bridges between the top and bottom of the cap is reduced. The structured configuration of the container flange prevents non-uniform slippage of the originality band after overcoming the flange point of the flange. Since a non-uniform load is therefore prevented and, therefore, locally excessive of the bridges, the originality band, including its joining bridges, can be stretched to the extent of its original and natural dimensions (at the time prior to assembly ). Therefore, the premises for a clean and uniform breakage of the junction points during screwing are significantly improved.

For the first opening of a container with external thread elements and a radially directed external thread flange and a radially directed outward flange extending around the periphery, as well as with an originality closure according to the invention, demonstrates it is especially advantageous if the flange is arranged below the thread elements, the flange presented a structure with at least one recess that extends around the periphery near the flange of the flange. It is convenient in this regard that the retention rib radially inwardly directed and formed on the inner surface of the originality band can be embedded in the recess when the closure is rotated to open the container.

In this way, the breakage of the joint bridges designed as theoretical break points between the upper and lower cap portions during the first closing opening is favored. Since the retention nerve is embedded in this first recess for the moment, said nerve is guided to the substantially horizontal blocking position, by which, by continuing to screw, a substantially uniform expansion of the breakable band against thickening is achieved. from the flange of the bottle. In particular, the "withdrawal effect" is avoided, that is, the drag on one side of the originality band on the flange, and, therefore, a simultaneous breakage of all theoretical break points is favored.

Likewise, the first opening of the originality closure is facilitated when the retention flange has a truncated cone-shaped transverse guide surface that, starting from the neck of the container near the elements of

018 156 threaded, diverging outwardly and in the direction of the bottom of the container, as well as an adjacent upper arc-shaped wall that runs from the guide surface to the top of the flange, and which lies below the flange a surface guide as a cone trunk that converges downwards in the bottom direction of the container. It is convenient in this respect that the cone-shaped guide surface converges with an angle of approximately 30 to 45 ° with respect to the plane extending transversely to the axis of the container.

The originality band can thus slide during the first screwing of the cap on the bottom ascending guide surface and can be carefully guided in this way into the lower recess. Only after the insertion in this recess, the dilatation forces acting on the joining bridges become so large, by continuing to screw the cap, that these bridges can be torn apart. Since the originality band is seated horizontally and prestressed in the lower recess, said band is pressed even more tightly and firmly against the flange in this advantageous position due to the supplementary screwing of the cap, thus restricting its simultaneous rotation and therefore, the theoretical break points are additionally requested.

The invention also concerns a process for the manufacture of an originality closure.

There is, in particular, the problem of creating a process for the manufacture of closures of the aforementioned class that favors a simple and cost-effective manufacture of the closures according to the invention.

This problem is solved by the fact that in the process according to the invention, a single-piece closure based on plastic material is first formed, which has an upper part and a lower part that is connected with the upper part, a original seal band that is connected with the lower part of the cap through an annular area of ​​smaller cross section and which has a radially inwardly directed rib near its lower end edge, and in which a multitude of bridges arranged on the periphery and projections bent inwards are then molded, by means of a creasing and pressing process, in the area of ​​the lateral wall of the closure located between the originality band and the lower part of the skullcap. This procedure has the advantage that the closure cap can be modeled in one piece, as usual, and therefore a subsequent assembly of individual parts of the cap that causes costs is dispensed with.

For the realization of the process of creasing and pressing it is convenient that the originality closure be guided in the area between the originality band and the lower part of the cap with its outer wall on an arc-shaped blade consisting of leaf segments, which cuts from side to side of the caps in the areas provided for it and presses against a molding plate located inside the cap.

It has been proven that this cutting and pressing process can be carried out without breaking the bridges at high production rates of 600 caps per minute. It has also been observed that this arrangement of the cutting blade guarantees a thickness of the bridges that can be repeated constantly. Due to the process of creasing and pressing, the joint bridges arranged in the periphery and the projections angled inward are produced in a single operation, which serve as stop elements to prevent lateral displacement of the originality band during the first assembly of the skullcap. The process according to the invention allows a cleft of the cap and a conformation of the bridges both in the hot and in the cold state and, therefore, can be applied to all the usual plastic materials. The procedure is also very flexible. By simple replacement and adjustment of the cutting blade, the geometry and thickness of the bridges can be varied. The blade may be arranged, for example, so that it leaves behind an initiation or a groove on the bridges formed, to eventually predetermine the breakage initiation points or reduce the breaking force. They can also be produced, for example, bridges whose thickness varies around the periphery of the cap.

The invention also relates to a device for the practical implementation of the method according to the invention, which has a guide pin that attacks inside the cap and has a shear plate and a molding mandrel, which cooperate with a cutting blade subdivided into cutting teeth, the cap being retained on the guide pin during the cutting and pressing process.

Other embodiments of the invention are found in the dependent claims.

Next, the invention is still described in more detail by referring to essential details pertaining thereto and by means of examples of execution and drawings according to the invention.

They show:

1 shows a perspective view of a closing cap according to the invention before the simultaneous formation of bridges and projections,

Figure 2 a view similar to Figure 1, but with a finished cap presenting a seal band of originality,

Figure 3 shows a side elevational view of the cap shown in Figure 1, on an enlarged scale and in partial section along line 3-3 of Figure 1,

Figure 4 an elevation view of the finished cap shown in Figure 2, on an enlarged scale and in partial section along line 4-4 of Figure 2,

Figure 5 a plan view of the cap shown in Figure 2, in section along line 5-5 of Figure 4,

Figure 6 a schematic front-side view of a machine for manufacturing originality closures according to the invention,

Figure 7 a side view in enlarged and simplified scale, in section along the

018 156 line 7-7 of Figure 6, which shows details of the construction of an individual guide pin with a corresponding cap,

Figure 8 a front elevational view, in allolargodelaline section 8-8 of Figure 7, which shows an arc-shaped blade to form the bridges and projections spaced apart from the closing cap when crossing its surface,

Figure 9 a very wide-scale sectional view of the details contained within the circle of strokes and points of Figure 7,

Figure 10 an enlarged view of the bridge-forming grooves of the arc-shaped segment knife,

Figure 11 a sectional view along line 11-11 of Figure 10,

Figure 12 a fragmentary view of a modified cutting edge,

Figures 13 and 13a, views taken partially in the closure zone mounted on the container, in a sectional representation,

Figures 14a and 14b, fragmentary sectional views on an enlarged scale of the areas enclosed within a circle in Figure 13a,

Figures 15a, 15b and 15c, views of the closure arrangement, showing the removal and relocation of closure,

Figures 16 to 19, views of previously known closures,

20 shows a fragmentary sectional view showing the structure of a container flange according to the invention, and

Figure 21 is a fragmentary perspective view of a view of the bridges according to the invention.

In figures 1 to 10 an originality closure designated in conjunction with 10 has been shown. If the biasic elements of the originality closure 10 are considered, the closure 10 substantially presents a cap 12 in the form of a cuipula with an inner thread 14 at the top 12a of the cap, which meshes with the thread 16 of the surface of the container, as well as an original seal band 18 that was connected to the lower end edge of the lower part 20 of the cap by means of a series of frangible bridges 22. The mouth of the container, designated in conjunction with 30, contains a standard thread 16 near the opening of the outlet 32, a flange 34 that retains the originality band 18 and that is disposed below the thread 16, and a second flange 36 which is axially arranged under the flange 34 that holds the originality band 18 (see Figure 13).

If the structural details and the composition of the originality closure 10 according to the invention are considered, it can be seen in figures 3 and 4 that for the originality band 18 (tear strip) a cross-section is provided that is larger than the area intermediate 40 that joins the lower end edge of the lower part 20 of the cap, in which the bridges 22 formed as theoiric rupture points are formed and in which the originality band 18 has an enlarged cross-section, in which an inwardly held retention rib 44 is contained which extends in a circle. In this embodiment, the originality band 18 comprises a first section 42a of substantially triangular cross-section and a second section 42b in substantially rectangular cross-section. Because of this conformation of the cross-section, the part of the originality band 18 that is below a horizontal plane PP lying across the nerve 44, is especially stable, while the area of ​​the originality band that is Above this plane, it elliptically joins the bridge area. The stability achieved by this conformation of the cross section prevents the originality band 18 from widening just during the first opening, whereby said band, upon breaking the bridges 22, can be held securely by the flange 34.

The cap 12 also contains a series of projections 50 or areas of similar lips arranged in a circle, which, as shown in Figure 4, are slightly chamfered inwards and request during the first assembly the shoulder 52 that was formed in the bottom edge of the bottom 20 of the cap. In this way, the originality band 18 is stabilized in a horizontal position in this phase, so that the bridges 22 are not stretched on one side nor the originality band 18 is displaced in a lateral direction. Due to the absorption of compression forces exerted on the original band 18 during the first assembly, as soon as it is pressed on the neck of the container or the flange 34, the projections 50 thus lead to excessive imbalances of tensions in the band and at points of theoretical breakage.

As shown particularly in Figure 14b, the projection 50 extends radially inwardly with a correspondingly determined alpha angle (α), so that its chamfered front side 51 is located below the shoulder 52, and during the assembly of the cap on the container press the lower end edge 53 of the lower part 20 of the cap on the external chamfered front side 51 of the projection 50. In this case, the pressure point is approximately at the midpoint 50a of the projection 50 (see Figure 14a) to thereby center the originality band relative to the cap and prevent its lateral displacement, as shown in Figure 17 It should be taken into account in this regard that the lower closing edge 53 of the lower part 20 of the cap, in a relaxed state, was distanced from the inclined outer surface 51 of the projection 50 in the manner shown in Figure 14b. This clearance is left as small as possible to also keep the pressure on the bridges as small as possible during the assembly process and improve the axial orientation of the originality band 18 during the assembly process (see Figure 14a) . The retaining flange 34, which, as depicted in an optimal way in Figures 13 and 14, is disposed on the container below the thread, has an upper guide area 60 in the shape of a cone trunk and a first recess 62 extending in a circle

018 156 and which is disposed between the retaining flange 34 and the flange 36. The base of the cone-shaped arc of the upper glutton zone 60 forms a designated ridge with 66, which constitutes the maximum diameter of the zone of upper guide 60, The lower sector of the flange 36 has an inverted cone trunk-shaped sector that serves as the lower guide area 64 below the recess 62. As best represented in Figures 14a and 14b, the upper guide area 60 is fused with the base ridge 66 in an arc-shaped upper joint wall 67 having a radius of curvature R1 suitable for mounting of the cap.

The lower guide zone 64 also transitions to an arc-shaped lower junction zone 68 with a suitable radius of curvature that facilitates the movement of the originality band 18 towards the horizontally secured position of the recess 62.

The lower diameter Dr of the rib 44 and the maximum diameter D1 of the retaining flange 34 keep a fixed relationship with each other such that the rib 44 can slide over the upper guide area 60 and be embedded below the lower guide area 64 as soon as possible. as the cap has occupied the definitively adjusted seat shown in figure 15a and in dashed lines in figure 13.

Next, the relationships of preferred diameters and inclination configurations are determined in more detail (see Figure 14b) to achieve the desired ease of mounting the closure, as well as the desired strength of the original seal band 18 against its removal from the neck of the container for a provision 10 of closing of container of determined size and configuration.

Typical dimensions 28 mm container neck

<td></td><td>cm</td>

<td>Ri</td><td> 0,185</td>

<td>R2</td><td> 0,025</td>

<td>Gave</td><td> 2,893</td>

<td>D2</td><td> 2,812</td>

<td>D3</td><td> 2,827</td>

<td>D4</td><td> 2,781</td>

<td>Φ3</td><td> 45°</td>

<td>^φ4</td><td> 45°- 60°</td>

Typical dimensions 28mm splice

Cm

<td>D_r</td><td> 2,781</td>

<td>T^T m</td><td> 0,038</td>

<td>T^T r</td><td> 0,203</td>

<td>H_r</td><td> 0,432</td>

<td>Φ1</td><td> 55^° -75^°</td>

<td>Φ2</td><td> 30^° -55^°</td>

<td>α</td><td> 35^°</td>

<td>β</td><td> 45^°</td>

Dimensions of a typical theoretical break point

<td></td><td></td><td>cm</td>

<td>Hb</td><td>Bridge height</td><td> 0,051</td>

<td>Tb</td><td>Bridge thickness</td><td> 0,038</td>

<td>Wb</td><td>Bridge Width</td><td> 0,102</td>

Number of connecting bridges (theoretical break points) for 28 mm, 8

The number of theoretical break points was increased with the diameter of the cap, for example it will be 10 to 33 mm (diameter of the cap).

Particularly in Figures 13 and 13a it is shown that the retention rib 44 is pressed during the first assembly of the cap 12 on the upper guide area 60 near the ridge 66 until the rib 44 exceeds the crest. The different bridges of junction 22 are then slightly compressed.

The arc-shaped junction wall 67, which has a fairly large radius of curvature R1 in the vicinity of the climax 66, provides a mechanically advantageous application of the cap 12. Indeed, when the band 18 dilates during movement on the upper guide section 60, the torque required during screwing to move the originality band 18 towards the cuospid 66 is increased to the same extent as the band is dilated. However, as soon as the retaining rib 44 has moved towards the rounded section near the cuospid 66, the turning torque grows more and more slowly and remains substantially identical during the slight further dilatation of the originality band, until This exceeds the climax 66. This occurs in the radius R2, which is advantageously configured large, at the junction point of the upper guide area 60 and the climax 66 of the originality band 18. The tendency for curvature of the junction wall R1 is enlarged to the extent that it approaches the culminating point 66, that is to say for a given growth of the expansion of the band near the maximum value of the dilatation, that is, at approaching the climax, the thread travel per unit of expansion increases with the approach to the climax 66. As mentioned above, this means that the growth of the tightening torque is reduced, even if the originality band 18 continues to be delayed in the area immediately in front of the climax.

It should be noted that in some examples of execution, especially with large diameters of the closure, some of the bridges 22 may be broken during the first opening of the closure when the band is dilated, while this exceeds the lower guide area 64 of a trunk shape cone, before it reaches a position in which the nerve 44 is firmly held in the recess 62 located above the flange 36 of the neck of the bottle. In an arc-shaped section of the originality band 18, in which premature rupture of the bridges occurs, the retention nerve 44 is in this case de6

018 156 under the recess 62, while the rest of the retaining rib 44 runs and is located in the recess 62. The bridges 22 then remain intact for the time being in this recess. However, as a result of the advantageous configuration of the invention, the forward rotation of the upper part of the cap leads to the breakage of all the bridges 22 and to the retention of the originality band 18 on the neck of the container, since the area of the band that runs and is located cleanly in the recess, is kept in a substantially horizontal position and, therefore, cannot be dragged on one side on the flange 34.

The fact that the diameter D4 of the container neck below the lower glutton zone 64 preferably corresponds approximately to the diameter Dr of the rib 44 of the band in a relaxed state also contributes to the uniform breaking of the bridges. , keeps the band 18 in a tensioned state.

Figures 14a and 14b show the development of the first assembly of a closing arrangement 10 according to the invention. It can be clearly seen here that the corresponding colonic lateral surface 51 of the projections 50 presses on the corresponding corresponding shoulder 52 in the lower end edge of the lower part 20 of the cap, to prevent uneven stretching of the originality band 18 during the first assembly of the cap 12 and a premature breakage of the tips 22. In addition, the projections 50 are arranged in a manner in which a lateral displacement of the originality band 18 is prevented, which will lead as a tendency to a request for the uniaon bridges 22 in an uneven manner and will favor a seizing of the band .

After exceeding the culminating point 66, the retaining rib 44 falls for the first time during the first assembly in the recess 62 and then, when the assembly is continued, it is pulled over the lower flange 36. It has been verified that it is relaxed from the band of originality after its complete expansion for the bridges of junction 22, whose tensioning is carried out in two stages, applies a much smaller application than in the case of the immediate complete tensioning of the band 18. Thus, it has been found that in executions in which breaks were observed during the single stage de-tensioning, the profile of the two-stage vessel could prevent a breakage of the bridges 22.

When the cap 12 is already completely mounted on the container, the retaining rib 44 is somewhat below the lower guide area 64 of the retaining flange 34. If the container must now be opened for use, it is simply rotated the cap 12 in the opening direction, the rib 44 sliding over the lower guide area 64 and snapping into the recess 62 which extends in the form of a circle. Through this process, the originality band 18 is temporarily retained in a horizontal position to cause a substantially uniform breakage of all the bridges 22, as soon as the upper part 12 of the cap moves axially upwards as the rotation in the opening direction continues . Once the container is opened, the originality band 18 is retained for the moment with its retention rib 44 in the recess 62. However, if the cap is seated again, the shoulder 52 requests the projections 50 and displaces the originality band so that it is loosely placed below the flange 34 of the container and the flange 38.

In some classes of plastic containers, particularly in plastic containers made by injection molding or by soup, it is desirable to significantly reduce the larger diameter of the neck of the container below the retaining flange 34. This is generally done to save on the amount of plastic consumed. When in these cases the premature rupture of the bridges 22 leads to the fact that not all of the rib 44 reaches the recess 62, a part of the originality band 18 can slide into the large-sized recess of the container that is formed due to the diameter reduced neck of the vessel. In these cases, it is convenient to mold a second recess 78 axially below the first recess 62, as designated by an arrow in Figure 20. The second recess 78 has a diameter D5 that is substantially equal to the diameter Dr of the rib 44, whereby the originality band 18 can be distended after its application, but at the same time an excessive displacement of the band 18 is avoided in case of that a premature breakage of the bridges 22 prevents the entire nerve 44 from reaching the secured position of the recess 62.

It should still be mentioned that the flange 34 or the profile on the container must not be continuously driven around the periphery, but may also be interrupted.

A method and a device for the manufacture of the closure arrangements 10 according to the invention have been shown in Figures 6 to 8. Figure 6 schematically represents a system or method for molding the bridges 22 and the projections 50 in the closure arrangements 10 according to the invention. In the present example, three stations of the process have been represented. Each station includes a supply station Sf to provide unprocessed caps 12, located with the open side facing up, to a guide pin M that attacks inside in the cap 12 and rotates it by means of the cutting edge in the form of arc of a cutting blade 80 of a substantially circular structure. The guide pin M rotates the cap 360 (clockwise) to mold all the bridges 22 and then remove the molded cap 12 from the guide pin by means of a gas press. At the end of the cutting bevel, the cap 12 has been rotated by the guide pin M to a position on the edge of the pressure plate 90 to transport it with the aid of air nozzles from the guide pin M to an installation of collective transport or similar.

Once again, the procedure and arrangement of the guide pin M are considered in more detail. In the first molding process, the intermediate zone 40 that joins the lower part 20 of the cap with the retaining rib 44 is molded with a

018 156 determined uniform cross section, preferably from 0.023 cm to 0.064 cm. The caps of this form are then led to a molding station for the bridges 22 and the projections 50, in which a stirrup attacks inside the cap 12 in the manner shown in Figure 7. As shown, the caps 12 with the open side up are placed against a pressure plate. The stirrup includes a molding zone 76 that faces the inner surface of the intermediate zone 40 and rotates the caps 12 through a cutting blade shown in Figure 8. In this figure 8 a cutting blade is shown with a substantially arched shape.

The sheet 80 is applied near the molding zone 76 and, as a result of the relative rotation of the cap 12 and the sheet 80, produces the bridges 22 arranged in a circle and the projections 50 inclined inward, which are molded by a pressing process It should be taken into account in this regard that the cutting blades 80 may have bevelled end edges 94 to ensure a clean cut and prevent the cap 12, 20 from being scratched along its entire length.

The elements and arrangement of the mandrel M are optimally represented with the aid of Figure 7. They contain a driving wheel 70 on which rotatable satellites 72 are mounted, which in turn rotate around a central stationary wheel 74. As shown, the stirrup 76 was fixedly mounted on the satellite 72, so that the rotation of the driving wheel 70 causes a right-hand rotation of the entire arrangement of the guide pins M on the stationary cutting blade 80. As It has been shown, the guide pin M has a shear plate 82 and a molding mandrel 84 which, as shown, cooperates with the cutting blade 80 to form the projections 50 by a cutting and pressing process. It should be noted that the cutting blade 80 was always mounted between retaining blocks 86 and that the cap 12 was normally in front of a pressure plate 90 during the cutting and molding process. The upper end edge 96 of the arc-shaped cutting blade 80 has a series of notches 98 equally spaced. While these form the bridges 22, the intermediate arc-shaped segments 100 serve to mold the projections 50, for which the guide pin M leads to the cap 12 on the surface of the cutting blade.

Even though the system and device for forming the bridges 22 and the projections 50 have been described in connection with an arc-shaped cutting blade 80, a straight-edge linear blade of the same configuration can also be used, then simply turning the cap 12 on the edge of the cutting blade, practically in the same manner as described above.

In addition, the system and the described cutting blade mechanism can be modified so that the arrangement and construction of the bridges can be varied individually. The arrangement of cutting teeth can be carried out, for example, so that in the cap 12 bridges to produce a sector of theoretical break points of smaller cross section at this site and thus also achieve a breakage of all the bridges near the edge bottom of the bottom 20 of the cap during the first opening. This arrangement can also provide the cap 12, 20 an aesthetically attractive exterior. Moreover, by means of a deliberate notching of the bridges 22, an exact adjustment of the thickness of the bridges and, therefore, of the tearing forces for the separation of the originality band can be achieved.

018 156