CLOSURES FOR CONTAINERS

Abstract: A snap action hinged closure (10) for a container (25), which closure comprises a body (11) having an outlet opening therein for attachment to the container and a cap (12) pivotally connected to the body by way of a hinge (13) and adapted to close the outlet opening in a closed position thereof. The body has a resiliently deflectable cantilevered arm (17) attached by its proximal end thereto and on the distal end of which arm the hinge (13) is provided. The cap (12) has a member (24) which is dimensioned and positioned relative to the body and the cap, so that when the cap is rotated about the hinge (13) to a mid-position shown between an open position and said closed position, the member (24) contacts the body (11) and deflects the arm (17) relative to the body whereby the resilience of the arm acts on the member to urge the cap from said mid-position into the respective one of the open and closed positions.

Description: CLOSURES FOR CONTAINERS Background of the Invention 1. Field of the Invention This invention relates to closures for containers and in particular, although not exclusively, to closures suitable for use on containers such as toothpaste tubes or the like. 2. Description of the Related Art The invention is concerned with closures that have snap action caps in which the cap is biased by a snap action device into both of a closed position, where the cap closes the open top of the container, and an open position, where the cap is well clear of the open top of the container. Whilst it is relatively easy to produce a closure with a snap action having a large diameter cap, it is not so easy to provide such snap action on small diameter caps of the size usually used for collapsible tubes such as toothpaste tubes. In GB-A-1503121 there is disclosed a snap action cap in which the body of the closure has a rigid tongue (16) and the cap has a flexible blade (17) which bears on the tongue (16) and provides the bias to move the cap to and from the open and closed positions. In this design the hinge is mounted on a substantially rigid part of the body and hence not only has to take the wear and tear as a hinge, but is subjected to tensile loads which could accelerate wear of the hinge. In US-A-4625898 there is shown two embodiments of an invention concerning snap action closures. The embodiment of Figures 11 to 18 comprises a hinged cap in which a film hinge is mounted on a substantially rigid part of the body. The cap has two lugs (430, 432) which bear against the body to slide against the body and elastically deform the film hinge. In a second embodiment shown in Figures 19 and 20, flexible "posts" are formed on the body against which the lugs slide, but here again the film hinge is mounted on a rigid part of the body and is subjected to tensile loads as well as the normal wear and tear of a hinge. The present invention seeks to provide a snap action closure which is easy to open and close and provides a durable biasing means and hinge means to achieve the snap action. The closure to which this invention relates achieves the durability of the biasing means and hinge means by making the biasing means in the form of a resilient cantilevered arm on which the hinge is mounted. Summary of the Invnetion According to the invention there is provided a snap action hinged closure for a container, which closure comprises a body having an outlet opening therein for attachment to the container and a cap pivotally connected to the body by way of a hinge means and adapted to close the outlet opening in a closed position thereof, said body having a resiliently deflectable cantilevered arm attached by its proximal end thereto and on the distal end of which arm the hinge means is provided, and the cap having a member which is dimensioned and positioned relative to the body and the cap, so that when the cap is rotated about the hinge means to a mid position between an open position and said closed position, the member contacts the body and deflects the arm relative to the body whereby the resilience of the arm acts on the member to urge the cap from said mid position into the respective one of the open and closed positions. Brief Description of the Drawings The invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a cross-sectional elevation of a closure constructed in accordance with the present invention, showing the. closure in the position in which it is moulded, Figure 2 shows the closure of Figure 1 in position on the neck of a container and shows the closure with the cap in the open position, Figure 3 shows the closure of Figure 1 in position on the neck of a container, and shows the closure with the cap part-way between the open position and the closed position, Figure 4 shows the closure of Figure 1 in position on the neck of a container, and shows the closure with the cap in the closed position, Figure 5 shows a view of the closure in the direction of arrow A of Figure 4, and Figure 6 shows a second embodiment of closure in position on the neck of a container shown with the cap in the open position. Description of Preferred Embodiments Referring to the drawings, a closure 10 comprises a single plastics moulding comprising a cylindrical body 11 and a cap 12. The cap 12 is joined to the body 11 by means of an integral film hinge 13 as will be described in greater detail below. The body 11 includes a cylindrical internally threaded skirt 14. The thread on the skirt 14 is of a suitable size and shape to enable the body to be screwed on to the neck of a container 25. Further types of fittings, other than a screw thread, could be used. For example, a circular collar or rib could be provided in the body 11 which cooperates with a groove on the neck of the container 25. The body 11 has an end wall 15 which is provided with a spout 15a through which contents of the container 25 can be dispensed when the closure 10 is in its open position. The wall of the skirt 14 is of substantially uniform thickness except in the vicinity of the hinge 13. In this region, the skirt is moulded so as to define a recess 16 and a cantilevered arm 17 which has its proximal end connected to the free edge of the skirt 14. The arm 17 is best seen in Figure 5 and has a small cut-out 19 formed centrally along the line 13a of the hinge 13. The cap 12 is generally cylindrical and comprises a top surface 20, with a skirt 21 around the peripheral edge of the top surface 20, a contained circular flange 22 which is dimensioned and shaped to fit over the spout 15a when the cap 12 is in the closed position, and an outer projection 23 which provides a convenient lever against which a user can press a thumb to move the cap 12 between open and closed positions. The cap 12 is also provided with a member in the form of a tongue 24 which extends radially relative to the hinge line 13a and which is sized so that its dimension x measured radially from the hinge line is slightly greater than the dimension y measured from the body 11 to the hinge line 13a. The cut-out 19 in the arm 17 is also dimensioned to receive the tongue 24 when the cap is in the closed position. The tongue 24 is positioned relative to the cap so that when the cap is in the closed position the tongue lies in the plane of the arm 17. In operation, the snap action is achieved as follows. The body 11 is initially mounted on the neck of a container 25 with the closure in the position shown in Figure 1. The cap is moved to the closed position from the moulded position of Figure 1 by first moving it to the open position shown in Figure 2. In this position, the tongue 24 is brought into contact with a relatively rigid part of the body 11 and the arm 17 is substantially unstressed or only slightly stressed. The line 13a of the hinge 13 is positioned relative to the top edge of the skirt 14 so that the tip of the tongue 24 contacts a vertically extending surface of the skirt recess 16. The cap 12 is then further moved so that it rotates about the hinge 13 and the tongue 24 slides down the body 11 and pushes the distal end of the arm 17, against its resilience, outwards to bend the cantilevered arm 17. At the mid position, where the tongue 24 is normal to the body 11 as shown in Figure 3, the cap is unstable. Further movement in the anticlockwise direction past the mid position shown in Figure 3 causes the cap to snap down into the closed position, due to the resilience of the arm 17 exerting a force on the tongue 24 and causing the tongue 24 to rotate the cap. The resilience of the cantilevered arm 17 provides a significant force on the tongue 24 to snap the cap into the closed position but this force is not such as would tear the film hinge 13 apart. Furthermore, because the hinge 13 is itself mounted on and movable bodily with, the distal end of the arm 17, and the arm 17 is relatively long, (and hence can be made relatively thin) , a clean snap action is possible with relatively low forces being imposed on the hinge 13. It will be appreciated that to open the cap 12 from the closed position shown in Figure 4, a user places a thumb on the lever 23 and prises the cap open. This causes the tongue 24 to slide up the wall of the body 11 to the unstable mid position shown in Figure 3, and bends the arm 17 outwards. Once the tongue 24 passes the mid position shown in Figure 3 the resilience of the arm 17 exerts a force on the tongue 24 as the arm returns to its unstressed state. This urges the tongue 24 to rotate the cap to the open position. It is .to be understood that the body 11 need not be cylindrical and could be of any suitable shape. Furthermore, it is preferred that the hinge 13 be formed as a film of relatively thin plastics material compared with the rest of the cap. If desired, the hinge could be made with separate parts held together by a hinge pin or any other type of hinge could be used. It is to be understood that two tongues 24 could be provided; one at each end of the hinge line 13a. In this case the arm 17 would be provided with appropriately positioned cut-outs to receive the two tongues 24. In a further embodiment, which may be slightly easier to mould, the projection 23 is omitted and, to facilitate easier opening, the part of the skirt 14 diametrically opposite the hinge 13 is provided with a thumb recess so that the skirt 21 of the cap overhangs the thumb recess when in the closed position. A cap of this design would be opened by pushing up the cap edge in the region of the thumb recess. The cut-out 19 can be much longer than is shown in Figure 5 and can effectively divide the cantilever arm 17 into two arms one located either side of the tongue 24. In the embodiment of closure shown in Figures 1 to 5, the member 24 bears against a substantially rigid part of the body 11. However, Figure 6 shows a modification in which an upstanding tab 30 is formed on the body adjacent to the arm 17 and hinge 13, the tab 30 being sufficiently thin to flex under pressure exerted by the member 24 as the cap moves through the raid position. Thus, with the arrangement of Figure 6, a part of the forces generated to provide the snap action arise from a deflection of the tab 30 as well as from a deflection of the arm or arms 17. Figure 6 also shows the closure 10 snap-fitted to the container 25 through the co-action of a groove 31 and rib 32.

Claims: CLAIMS 1. A snap action hinged closure for a container, which closure comprises a body having an outlet opening therein for attachment to the container and a cap pivotally connected to the body by way of a hinge means and adapted to close the outlet opening in a closed position thereof, said body having a resiliently deflectable cantilevered arm attached by its proximal end thereto and on the distal end of which arm the hinge means is provided, and the cap having a member which is dimensioned and positioned relative to the body and the cap, so that when the cap is rotated about the hinge means to a mid position between an open position and said closed position, the member contacts the body and deflects the arm relative to the body whereby the resilience of the arm acts on the member to urge the cap from said mid position into the respective one of the open and closed positions. 2. A closure according to claim 1, wherein the body comprises an end wall which has the outlet opening therein and a skirt portion which has means for attaching the body to a container, the proximal end of the cantilevered arm being connected to the skirt at the free edge of the skirt portion. 3. A closure according to claim 2, wherein the skirt portion is moulded to form a recess between the body and the arm. 4. A closure according to claim 1, wherein the arm is provided with a cut-out at a position along the length of the pivotal axis of the hinge means and the member is dimensioned and positioned relative to the cap and the cut¬ out, so that, when the cap is in the closed position, the member is accommodated in the cut-out and lies in the plane of the cantilevered arm. 5. A closure according to claim 4, wherein the hinge means is spaced a distance (x) from the body when the cap is in the closed position and the member has a dimension (y) , measured radially from the pivotal axis of the hinge means, which is greater than (x) . 6. A closure according to claim 4, wherein the cut-out is provided at an intermediate position along the pivotal axis of the hinge means. 7. A closure according to claim 1, wherein the body is provided with a deformable portion against which said member engages in the mid position of the cap, flexing of the deformable member augmenting the resilience of the arm in generating the force to urge the cap from said mid position into the respective one of the open and closed positions. 8. A closure according to claim 1, in which there are two cantilever arms provided, one on each side of the member. 9. A closure according to claim 1, wherein the hinge means is a plastics film hinge.

Inventors: VON SCHUCKMANN ALFRED EVERHARD, VON SCHUCKMANN, ALFRED, EVERHARD, FRIEDRICH
Applicants: COURTAULDS PACKAGING LTD, VON SCHUCKMANN ALFRED EVERHARD, COURTAULDS PACKAGING LIMITED
Application year: 1993
Main classification: B65D47
IPC codes: B65D47