Venting cap for liquid containers

Abstract

The present invention concerns a venting cap for liquid containers which besides a pouring opening also has a venting opening with a venting spigot provided with a corresponding venting cap. The venting cap has a closed head plate and a cap skirt which extends downwardly from the head plate and has at least one cylindrical portion having a female thread, wherein above the female thread the cap skirt has a venting portion at which there are provided at a spacing relative to the head plate retaining lugs which extend radially inwardly and define a free inside radius which is smaller than the inside radius of the thread.

Claims

1. A venting cap for liquid containers comprising: a closed head plate (1) and a cap skirt (2) which extends downwardly from the head plate and has at least one cylindrical portion (3) having a female thread, wherein above the female thread (5) the cap skirt (2) has a venting portion (4) at which there are provided at a spacing relative to the head plate (1) retaining lugs (11) which extend radially inwardly and define a free inside radius (r) which is smaller than the inside radius (r) of the thread (5), characterised in that the cap skirt (2) is closed along an entire periphery of the cap skirt (2) and the inside surface of the cap skirt (2) has venting passages (8) in the form of elongate recesses in the inside wall of the cap skirt (2), which extend axially in and from the venting portion (4) above the retaining lugs (11) and through the female thread in the direction of the lower free edge of the cap; wherein the inside of the venting portion (4) has retaining portions (7) disposed above the female thread, which are spaced from each other in the peripheral direction and which extend axially, the retaining portions further defining an inside surface of a radius (r2) which is smaller than the nominal radius (R) of the female thread and at which the retaining lugs (11) are arranged, the venting passages (8) extending between said retaining portions.

2. A venting cap for liquid containers as set forth in claim 1, characterized in that the radius of the retaining portions (7) is smaller than the core radius (r) of the female thread.

3. A venting cap for liquid containers as set forth in claim 2, characterized in that the radius (r2) of the retaining portions (7) is at least 30%, preferably at least 70%, of the core radius (r) of the female thread.

4. A venting cap for liquid containers as set forth in claim 1, characterized in that the radius (r2) of the retaining portions (7) is at least 30%, preferably at least 70%, of the core radius (r) of the female thread.

5. A venting cap for liquid containers as set forth in claim 1, characterized in that the outside of the cap skirt (2) has axially extending and radially outwardly extending ribs (6), on the inside of which the venting passages (8) are provided.

6. A venting cap for liquid containers as set forth in claim 1, characterized in that the inside surface of the cap skirt (2) has portions which project radially inwardly and are set back outwardly alternately in the peripheral direction, wherein the outwardly extending portions form the venting passages (8).

7. A venting cap for liquid containers as set forth in claim 1, characterized in that the nominal radius (R) of the female thread is between 10 and 30 mm.

8. A venting cap for liquid containers as set forth in claim 1, characterized in that the sum of the cross-sections of all venting passages (8) in the region of the female thread radially outside the nominal radius (R) of the female thread is at least 10 mm.sup.2.

9. A venting cap for liquid containers as set forth in claim 1, characterized in that the minimum cross-section of each individual venting passage (8) is throughout at least 2 mm.sup.2.

10. A venting cap for liquid containers as set forth in claim 1, characterized in that the cross-section of each venting passage (8) above the female thread (5) is at least as large as in the region of the female thread (5).

11. A venting cap for liquid containers as set forth in claim 1, characterized in that the venting passages extend to the lower edge of the cap skirt (2).

12. A venting cap for liquid containers as set forth in claim 1, characterized in that an anti-tamper band (9) is provided at the lower edge of the cap skirt (2) and as an axial prolongation thereof.

13. A venting cap for liquid containers as set forth claim 1, characterized in that the inside of the head plate (1) of the cap has at least one sealing element.

14. A venting cap for liquid containers as set forth in claim 1, characterized in that an axial length of the radially outwardly disposed bottom of the venting passages (8) is disposed over a substantially constant radius around an axis of the cap which is defined by the cylindrical portion of the cap.

15. A venting cap for liquid containers as set forth in claim 4, characterized in that the radius (r2) of the retaining portions (7) is at least 70% of the core radius (r) of the female thread.

16. A venting cap for liquid containers as set forth in claim 3, characterized in that the radius (r2) of the retaining portions (7) is at least 70% of the core radius (r) of the female thread.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further advantages, features and possible uses of the present invention will be apparent from the description hereinafter of a preferred embodiment and the related Figures in which:

(2) FIGS. 1a-d show various views of the closure cap according to the invention, and

(3) FIG. 2 shows a perspective view of a corresponding venting spigot on a container wall.

DETAILED DESCRIPTION

(4) FIG. 1a shows a side view of a venting cap according to the invention. The venting cap 10 has a flat head plate 1 from which a markedly structured cap skirt 2 extends downwardly. The cap skirt 2 can be notionally divided in the axial direction into a thread portion 3 and a venting portion 4.

(5) The cap skirt 2 also has a plurality of ribs 6 which extend over substantially the entire axial length of the cap skirt 2 and which project radially outwardly. The venting portion 4 has between the ribs 6 radially somewhat inwardly displaced skirt portions which are here referred to as retaining portions 7. In the region of the thread portion 3 in addition the cap skirt 2 is displaced somewhat radially inwardly between the ribs 6, but defines a larger diameter than in the region of the retaining portions 7.

(6) FIG. 1b is a sectional view containing the axis 15 of the cap. It will be seen that the thread portion 3 has a female thread 5 comprising a plurality of segments separated from each other by venting passages 8. The venting passages 8 extend over the entire length of the inside of the cap skirt and in particular also into the venting portion 4 where the venting passages 8 are arranged alternately in the peripheral direction with retaining portions 7. At the lower end of the retaining portions 7, the edge region of which is also reinforced by axially extending reinforcing ribs 7a, it is possible to see radially inwardly projecting retaining lugs 11. In specific terms here the retaining lugs 11 are formed by thickened lower ends of reinforcing ribs 7a.

(7) The reinforcing ribs do not extend entirely to the inside of the head plate 1 and can thus with their upper end faces hold a sealing disk which is arranged at the head plate and whose radius is larger than the radius defined by the reinforcing ribs 7a. In this case the spacing of the reinforcing ribs relative to the head plate 1 is matched to the thickness of the sealing disk.

(8) Near its lower edge the cap skirt has a peripherally extending flange edge 12, wherein provided at the lower edge of the cap skirt 2 there is also a so-called anti-tamper band 9 which is connected to the edge of the cap skirt by way of easily breakable bridges and which prolongs the cap overall in the axial direction, the anti-tamper band 9 being of an outside diameter approximately corresponding to the outside diameter of the flange edge immediately above the anti-tamper band 9. The flange edge 12 is intended to prevent the tooth configurations on the inside of the anti-tamper band 9 being manipulated in order to release the cap 10 from the thread of a venting spigot without tearing the easily breakable connections between the cap skirt 2 and the anti-tamper band 9.

(9) FIG. 1c shows a view from below into the open underside of the cap of FIG. 1a. Here too it is possible to see the female thread 5 which comprises individual leg segments and which is interrupted by the venting passages 8. The venting passages 8 are defined precisely where the ribs 6 are provided on the outside, that is to say they form a hollow space in the interior of the ribs. In the peripheral direction the width of the venting passages 8 is typically between 1 and 5 mm, preferably between about 2 and 3 mm, wherein the depth of the venting passages 8 in the venting portion 4 is greater than in the thread portion because the retaining portions 7 between the venting passages 8 in the region of the venting portion project radially further inwardly than the thread portion 3. The bottom of the venting passages 8 however is throughout radially outside the bottom of the female thread 5 and the bottom of the venting passages, over the axial length of those passages, is disposed substantially on the same radius. If the outside surfaces of the ribs 6 jointly define a conical surface involving a very small cone angle then the bottom of the venting passages 8 can also be disposed on a corresponding cone surface which is somewhat smaller in diameter.

(10) Unlike the situation shown in FIG. 1c the radius r2 of the retaining portions 4 in the case of this embodiment is in precise terms not defined by the wall portions identified by reference 7 but by the reinforcing ribs 7a which however are only visible in FIG. 1b, being however concealed by the retaining lugs 11 in FIG. 1c. The radius r2 would thus be somewhat smaller than can be seen in FIG. 1c, but always still larger than the radius r1 of the retaining lugs 11.

(11) FIG. 1d shows a view on to the closure of FIG. 1a from above, looking on to the head plate 1. It will be seen that the head plate 1 is substantially a circular disk with star-shaped enlargements which are formed by the upper end faces of the ribs 6. Between the ribs 6 it is possible to see the retaining portions 7 defining the periphery of the central circular disk. It will also be seen that in the region of the retaining portions 7 the venting portion 4 is of a markedly smaller radius than the threaded portion 3 which has the female thread on its inside. This plan view also shows the flange edge 12 covering the top side of the anti-tamper band 9.

(12) FIG. 2 shows a perspective view of a venting spigot 20 arranged at the upper wall 25 of a container (not shown in greater detail here). The venting spigot 20 comprises a lower portion 21 having a male thread and an upper neck 22 which has a projecting edge 23 in the proximity of its upper end. The outside diameter of the neck is identified by r3 and the outside diameter of edge 23 is identified by r5. The core diameter of the male thread 21 is identified by r4. In use the venting cap 10 is fitted on to the venting spigot 20 and the retaining lugs 11 are pushed away over the projecting edge 23, the edge 23 and/or the lugs 11 or the retaining portions 7 being elastically deformed in that case so that the retaining lugs 11 can latch behind the edge 23 and are then only axially moveable in the region of the neck 22 between the thread 21 and the edge 23. When the retaining lugs 11 have passed the projecting edge 23, the female thread 5 can come into engagement with the male thread 21 and the venting cap can be screwed on to the thread 21. In that case the inside surface of the head plate 1 or a sealing disk arranged on that inside surface of the head plate come into sealing engagement with the upper end face of the neck 22. To open the venting spigot the cap 10 is unscrewed from the venting spigot 20 until the threads 21 and 5 are out of engagement, in which case however the retaining lugs 11 which still engage behind the edge 23 on the neck 22 prevent complete release of the venting cap from the venting spigot 20, even if forcible removal of the venting cap from the venting spigot still remains entirely possible. The retaining lugs 11 however prevent the cap 10 from being simply pulled off the venting spigot and in that way signal to the user that for venting purposes the cap only has to be and is only intended to be released from the thread engagement, but does not have to be and is not to be completely removed.

(13) After release of the thread engagement the head plate 1 or its seal is at a spacing from the end of the neck 22 so that air can pass into the container by way of the passages 8 on the inside of the venting cap 10 and can flow from the passages 8 into the central opening of the container neck 22. The inflowing air equalizes a reduced pressure which otherwise occurs when pouring liquid out of the pouring opening of the container. As can be seen the venting cap 10 is completely closed outwardly, that is to say the head plate 1 and the cap skirt 2 form a closed unit to below the flange edge 12 and the lower edge of the cap skirt 2.

(14) In use of the venting cap the anti-tamper band 9 is separated from the lower edge of the cap skirt 2 and (irrespective of the position of the anti-tamper band) air can flow past the lower edge of the cap skirt 2 for venting the container and through the passages 8 past the male thread 21 and the neck of the venting spigot 20 and enter the central opening of the neck 22. A direct straight-line path from the exterior through the openings in the cap skirt and into the central opening of the neck 22 is no longer possible as a result. The air or gas for venting purposes therefore necessarily has to follow a roundabout path which securely prevents at least relatively large dirt particles from being drawn in.

REFERENCE NUMERALS

(15) 1 head plate 2 cap skirt 3 thread portion 4 venting portion 5 female thread 6 rib(s) 7 retaining portion 7a reinforcing ribs 8 venting passages 9 anti-tamper band 10 venting cap 11 retaining lugs 12 flange edge 15 axis 20 venting spigot 21 lower portion/male thread 22 neck 23 projecting/protruding edge 25 upper wall of a container