Opening mechanism

Abstract

A single-handed opening mechanism for a container (1) holding a pourable substance comprising an elongate sealing element (2) which is moveable from a first closed position to a second open position. The elongate sealing element (2) is deformable and moves from the first closed position to the second deformed open position by the application of a squeezing force applied by the user's hand substantially along the length of the elongate sealing element (2).

Description

[0001] The present invention relates to a single-handed opening mechanism for a container holding a pourable substance. The invention is particularly suitable for single-portion containers such as those used for adding milk to tea and coffee.

[0002] The most common liquid containers used, for example, for adding milk to tea and coffee typically comprise a plastic container and a foil lid. To open containers of this type, a two-handed operation is required, with one hand holding the container and the other pulling off the lid before the contents can be poured out. An object of the present invention is to provide a container that can be opened by a single hand only.

[0003] Other liquid containers of the single-handed opening type, for example single portion sachets, involve squeezing the container to create a tensile force on a weakened portion, causing it to rupture. The key feature of this type of container is that the forces applied to the container are transferred through the liquid within the container to rupture said container. Such an arrangement suffers from the disadvantage that if the rupture is caused by an increase in the pressure of the liquid, the liquid will also pass through the rupture under pressure and result in the contents jetting out of the container in an uncontrolled manner.

[0004] EP-A-0078761 discloses an example of such a sachet type container. This document discloses a sealed container comprising two layers of thermoplastic film heat sealed together, a v-shaped area being formed as part of the heat sealed pattern, with the apex of the v directed toward the interior of the container. When pressure is applied to the container, such as by squeezing it, the heat seal ruptures, beginning at the apex of the v, and continuing through the heat seal in a well defined path. As a result, the contents of the container, such as an individual serving of ketchup, can be dispensed from the container.

[0005] A more sophisticated arrangement of a sachet type container is described in U.S. Pat. No. 5,131,760 which discloses a package which may contain a fluid material which is capable of being discharged from the package by the application of manual pressure from a thumb and forefinger to the package so as to cause the package to burst in a controlled fashion to discharge the fluid material contained within the package. The package comprises a second chamber which receives the fluid material discharged from a first containing chamber after the first containing chamber is burst by manual pressure. This second chamber further has a seal which will burst under a reduced amount of manual pressure than required to burst the first containing chamber, so as to control the rate and manner of discharge of the fluid from the package.

[0006] As an alternative to a sachet which dispenses its contents through a ruptured heat seal, WO 01/17875 discloses a sachet which has a semi-rigid member with a weakened region formed thereon so that upon bending across the weakened region the semi-rigid member will fracture along the weakened region. The sachet also has a reservoir formed by overlaid first and second flexible film layers which are adapted to contain a flowable substance. In use, fracturing the weakened region allows the flowable substance to be dispensed.

[0007] All the single-handed opening type arrangements described above suffer from the disadvantage that the container is ruptured and the contents are discharged simultaneously. This results in an uncontrolled discharge.

[0008] An alternative opening mechanism for a liquid container is described in U.S. Pat. No. 3,175,749 which discloses a carton having a pour spout which opens when the carton is squeezed in the vicinity of the pour spout and automatically closes when the pressure is released.

[0009] The disadvantage with the above carton arrangement is that in order to open the pour spout the body of the container must be squeezed. Squeezing the body of the carton transmits forces to the liquid contained within, causing random motion of the liquid. Further, as the body of the carton is squeezed the height of the liquid contained within will rise. The random motion of the liquid combined with an overall rise in the height of the liquid as the spout is opened may result in spillage. Such an effect will be increased as the container size reduces since there will be less space between the liquid surface and the spout.

[0010] The object of the present invention is to provide an opening mechanism which addresses the disadvantages of the prior art arrangements described above i.e. a single-handed opening mechanism for a container holding a pourable substance wherein the container is openable while imparting a negligible amount of pressure on the contents within. Such a mechanism has the advantage over the prior art arrangements that the container may be first opened and then subsequently poured in a controlled manner thereby limiting the chance of spillage. Pourable substances may include low viscosity liquids such as milk, medium viscosity liquids such as ketchup sauces and face/body lotions, high viscosity and non-Newtonian liquids such as clotted cream and toothpaste, liquids containing solid particles such as French dressings and granular solids such as salt. It may be necessary, particularly in the case of high viscosity liquids, to squeeze the container body after opening in order to controllably dispense the contents.

[0011] According to the present invention there is provided a single-handed opening mechanism for a container holding a pourable substance comprising an elongate sealing element which is moveable from a first closed position to a second open position wherein the elongate sealing element is deformable and moves from the first closed position to the second deformed open position by the application of a squeezing force applied by the user's hand substantially along the length of the elongate sealing element.

[0012] Preferably, the elongate sealing element is resealable following use.

[0013] Preferably, the elongate sealing element comprises an openable/closable portion, said openable/closable portion being closed in the first position and said openable/closable portion defining an aperture in the second position.

[0014] Preferably, said openable/closable portion comprises a substantially cross shaped slit in the closed position.

[0015] Preferably, said openable/closable portion comprises a plurality of hinge points.

[0016] Preferably, said aperture is substantially diamond shaped.

[0017] Preferably, said elongate sealing element consists of first and second substantially rigid portions and wherein the openable/closable portion is located between said first and second substantially rigid portions.

[0018] Advantageously, said elongate sealing element further comprises a locking element for locking the mechanism in the first closed position.

[0019] Preferably, said locking element is constrained to slide on the elongate sealing element.

[0020] Preferably, the elongate sealing element further comprises a breakable diaphragm, said breakable diaphragm being broken on moving from the first closed position to the second open position.

[0021] Preferably, the elongate sealing element is fabricated from a plastic material.

[0022] Alternatively, the elongate sealing element is fabricated from a cardboard material.

[0023] The present invention also provides a container comprising a single-handed opening mechanism.

[0024] The present invention also provides a method of manufacturing the single-handed opening mechanism for a container holding a pourable substance, the method comprising moulding the elongate sealing element and the container body as a single unit, filling the container body with a pourable substance and sealing the container.

[0025] Alternatively, there is provided a method of method of manufacturing the single-handed opening mechanism for a container holding a pourable substance, the method comprising moulding the elongate sealing element, sealing the elongate sealing element to a pre-formed container body, said pre-formed container body having two open ends and said elongate sealing element being sealed to the first of said ends, filling the container body with a pourable substance through the second of said ends and sealing the second end.

[0026] Alternatively, there is provided a method of manufacturing the single-handed opening mechanism for a container holding a pourable substance, the method comprising forming the elongate sealing element and the container body as a single unit from a sheet of material, said sheet of material being scored, folded and sealed to form an open-ended container, filling the container with a pourable substance and finally sealing the open end to form the elongate sealing element.

[0027] The present invention is particularly suitable for single-portion containers such as those used for adding milk to tea and coffee. Alternatively, the present invention may be used for larger multiple-portion containers. A preferred embodiment of the present invention which also comprises a locking element is particularly suitable for larger multiple-portion containers.

[0028] Preferred embodiments of the present invention will now be described by way of example with reference to the accompanying drawings in which:

[0029] FIG. 1 shows a filled and sealed container comprising an opening mechanism according to a first preferred embodiment of the present invention;

[0030] FIG. 2a shows the opening mechanism in FIG. 1 in the closed position;

[0031] FIG. 2b shows the opening mechanism in FIG. 1 in the open position;

[0032] FIG. 3 shows the openable/closable portion of the opening mechanism in

[0033] FIGS. 1 to 2b in greater detail;

[0034] FIG. 4a shows a filled and sealed container comprising an opening mechanism with a locking element according to a second preferred embodiment of the present invention;

[0035] FIG. 4b shows the container in FIG. 4a, with the locking element in a locked position; and

[0036] FIG. 5 shows the opening mechanism in FIGS. 4a and 4b in greater detail.

[0037] FIG. 1 shows a filled and sealed container 1 comprising a single-handed opening mechanism according to a first preferred embodiment of the present invention. The single-handed opening mechanism comprises an elongate sealing element 2 which is moveable from a first closed position to a second open position. The elongate sealing element 2 is deformable and moves from the first closed position to the second deformed open position by the application of a squeezing force applied by the user's hand substantially along the length of the elongate sealing element 2.

[0038] The container 1 is of the single-portion type such as may be used for adding milk to tea and coffee. The container 1 has typical dimensions of 35 mm by 45 mm. The container 1 is preferably manufactured by forming the opening mechanism and the container body 3 as a single unit using injection moulding, filling the container body 3 with a pourable substance and heat sealing the container body 3.

[0039] FIG. 2a shows the elongate sealing element 2 in FIG. 1 in the closed position. The elongate sealing element 2 consists of first and second substantially rigid portions 4, 5 and an openable/closable portion 6. The openable/closable portion 6 is located between said first and second substantially rigid portions 4, 5. The openable/closable portion 6 comprises a substantially cross shaped slit 7 in the closed position. The openable/closable portion further comprises hinge points 8, 9, 10, 11 located at the outer points of the cross shaped slit 7. The elongate sealing element 2 further comprises a breakable diaphragm 12 sealing the substantially cross shaped slit 7. The breakable diaphragm 12 is broken on moving from the first closed position to the second open position. The breakable diaphragm could be located either in the vicinity of the upper or lower surfaces of the elongate sealing element or alternatively, within the cross shaped slit.

[0040] In use, the user applies a squeezing force of F/2 to each end of the elongate sealing element 2 and substantially directed along the length of the elongate sealing element 2. The force F/2 is transmitted along the substantially rigid portions 4, 5 to the openable/closable portion 6 and the cross shaped slit 7. The cross shaped slit 7 deforms at the hinge points 8, 9, 10, 11, the breakable diaphragm 12 ruptures, and said cross shaped slit 7 opens to form a diamond shaped aperture 13 as shown in FIG. 2b. The openable/closable portion 6 opens to form the aperture 13 with limited deformation of the container body 3 and there is negligible pressure imparted on the contents. Thus the container 1 may be opened without spillage and the contents poured in a controlled manner.

[0041] FIG. 3 shows the openable/closable portion 6 of the elongate sealing element 2 of FIGS. 1 to 3 in greater detail indicating geometric features and forces resulting from squeezing the elongate sealing element 2. Typical values for the geometric parameters are: L=6.0 mm; b=1.0 mm; B=4.0 mm; w=3.2 mm; T=2.0 mm; diaphragm thickness, t=0.1 mm; e=0.5(B-b/2−(B/2−w/2))=1.55 mm. A typical value for the applied squeezing force, F, is F=7 lbs force=31.1 Newtons. The moments at point A are given approximately by the simplified equation Fudl=4.F.e/L2. Given the above values for F, e, and L, the opening force on the diaphragm, Fudl, is 5.36 N/mm, and the tensile force on the diaphragm is given by Ftensile=Fudl/t=53.6 N/mm2. This approximate calculation is predicted to be within 10% of a more complete finite element mesh analysis.

[0042] In this preferred embodiment, when the squeezing pressure is released after opening, the openable/closable portion 6 naturally springs back to an intermediate, ‘semi-closed’ position. Resealing this preferred embodiment is not of importance as the container is of the single-portion type which is thrown away after use.

[0043] This preferred embodiment is made of plastic. Selection of the type of plastic is based on achieving a number of goals: enough elasticity to prevent the opening mechanism tearing or fracturing at the hinge points when opened; not too much elasticity that the diaphragm simply stretches like a balloon without rupturing on moving from the first open position to the second closed position; a suitable balance of yield stress versus malleability so that the diaphragm can be moulded to the correct thickness with the required breaking stress; chemically inert against a range of liquids so that chemicals do not leach out of the container; low water absorption and permeability to provide an effective water barrier and prevent the container going soggy; low cost of material; melting temperature within range of existing packaging machinery.

[0044] FIGS. 4a and 4b show a filled and sealed container 20 according to a second preferred embodiment of the present invention comprising an elongate sealing element 21 with a locking element 22. The single-handed opening mechanism comprises an elongate sealing element 21 which is moveable from a first closed position to a second open position. The locking element 22 is constrained to slide on the elongate sealing element 21. Sliding the locking element 22 from a first unlocked position, as shown in FIG. 4a, to a second locked position, as shown in FIG. 4b, pulls the two sides of the openable/closable portion 24 together preventing the elongate sealing element 21 from opening on the application of a squeezing force.

[0045] The container 20 is of the multiple-portion type and has typical dimensions of 35 mm wide by 100 mm long. The container 20 is preferably manufactured by forming the elongate sealing element 21 using injection moulding and heat sealing the elongate sealing element 21 to a pre-formed container body 23. The pre-formed container body 23 has two open ends and the elongate sealing element 21 is heat sealed to one of the ends. The container body 23 is then filled with a pourable substance through the second of the ends and is heat sealed at the second end.

[0046] FIG. 5 shows the elongate sealing element 21 of FIG. 4a and 4b in more detail. The locking element 22 is in the first unlocked position and the openable/closable portion 6 is in the second open position forming a diamond shaped aperture 25. Sliding the locking element 22 from the first unlocked position to the second locked position pulls the two sides of the openable/closable portion 24 together thus closing the diamond shaped aperture 25 and preventing the elongate sealing element 21 from opening on the application of a squeezing force. The elongate sealing element 21 may be reopened by sliding the locking element 22 back to the first unlocked position and applying a squeezing force substantially along the length of the elongate sealing element 21.

[0047] The locking element is particularly useful as it prevents accidental opening of the container. For example, a container of cosmetic cream carried around in a handbag may be subjected to buffeting and squeezing forces. The locking mechanism would ensure that there is no accidental leakage.

[0048] The embodiments described here are formed using injection moulding and subsequently heat sealed. However, there are a number of different plastic moulding processes that may be used including injection, vacuum, blow and press. Similarly, there are a number of sealing processes including heat, glue and crimp.

[0049] Other preferred embodiments of the present invention are also envisaged. For example, a further embodiment of the invention may be manufactured in which the openable/closable portion automatically springs back from the second open position to the first closed position on releasing the squeezing pressure, thus closing and sealing the container without the need for a locking element. An alternative embodiment of the present invention may be manufactured by forming the elongate sealing element and the container body as a single unit from a sheet of material. The sheet of material would be scored, folded and sealed to form an open-ended container. The container body would be filled with a pourable substance and finally sealed at the open end to form the elongate sealing element. In this embodiment the sealing of the open end would form the substantially rigid portions of the elongate sealing element.

[0050] While this invention has been particularly shown and described with reference to preferred embodiments, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention as defined by the appended claims.

Claims

1. A single-handed opening mechanism for a container holding a pourable substance comprising an elongate sealing element which is moveable from a first closed position to a second open position wherein the elongate sealing element is deformable and moves from the first closed position to the second deformed open position by the application of a squeezing force applied by the user's hand substantially along the length of the elongate sealing element.

2. A single-handed opening mechanism as claimed in claim 1, wherein said elongate sealing element is resealable.

3. A single-handed opening mechanism as claimed in claim 1 or claim 2, wherein said elongate sealing element comprises an openable/closable portion, said openable/closable portion being closed in the first position and said openable/closable portion defining an aperture in the second position.

4. A single-handed opening mechanism as claimed in claim 3, wherein said openable/closable portion comprises a substantially cross shaped slit in the closed position.

5. A single-handed opening mechanism as claimed in claim 3 or claim 4, wherein said openable/closable portion comprises a plurality of hinge points.

6. A single-handed opening mechanism as claimed in any of claims 3 to 5, wherein said aperture is substantially diamond shaped.

7. A single-handed opening mechanism as claimed in any of claims 3 to 6, wherein said elongate sealing element consists of first and second substantially rigid portions and wherein the openable/closable portion is located between said first and second substantially rigid portions.

8. A single-handed opening mechanism as claimed in any previous claim, wherein said elongate sealing element further comprises a locking element for locking the mechanism in the first closed position.

9. A single-handed opening mechanism as claimed in claim 8, wherein said locking element is constrained to slide on the elongate sealing element.

10. A single-handed opening mechanism as claimed in any previous claim, wherein the elongate sealing element further comprises a breakable diaphragm, said breakable diaphragm being broken on moving from the first closed position to the second open position.

11. A single-handed opening mechanism as claimed in any previous claim, wherein the elongate sealing element is fabricated from a plastic material.

12. A single-handed opening mechanism as claimed in any of claims 1 to 10, wherein the elongate sealing element is fabricated from a cardboard material.

13. A container comprising a single-handed opening mechanism as claimed in any previous claim.

14. A method of manufacturing a single-handed opening mechanism for a container holding a pourable substance as claimed in any of claims 1 to 10, the method comprising moulding the elongate sealing element and the container body as a single unit, filling the container body with a pourable substance and sealing the container.

15. A method of manufacturing a single-handed opening mechanism for a container holding a pourable substance as claimed in any of claims 1 to 10, the method comprising moulding the elongate sealing element, sealing the elongate sealing element to a pre-formed container body, said pre-formed container body having two open ends and said elongate sealing element being sealed to the first of said ends, filling the container body with a pourable substance through the second of said ends and sealing the second end.

16. A method of manufacturing a single-handed opening mechanism for a container holding a pourable substance as claimed in any of claims 1 to 10, the method comprising forming the elongate sealing element and the container body as a single unit from a sheet of material, said sheet of material being scored, folded and sealed to form an open-ended container, filling the container body with a pourable substance and finally sealing the open end to form the elongate sealing element.

17. A single-handed opening mechanism substantially as herein described with reference to the accompanying drawings.

18. A method of manufacturing a single-handed opening mechanism substantially as herein described with reference to the accompanying drawings.