EP0858954A2

EP0858954A2 - Closure for food and liquid container

Info

Publication number: EP0858954A2
Application number: EP98301037A
Authority: EP
Inventors: John Bowers
Original assignee: Le Creuset SAS
Current assignee: Le Creuset SAS
Priority date: 1997-02-18
Filing date: 1998-02-12
Publication date: 1998-08-19
Also published as: CA2228751A1; KR19980071414A; GB9703318D0; JPH10245059A; GB2322122A; AU5389498A; CN1191198A

Abstract

A closure for an open-mouthed container is described. The closure includes a bottom closure member, the outer edge of which is sealable against the inner wall of the container and a top closure member which is connected to the bottom closure member. An actuating member is provided for moving the bottom closure member from the sealing position to an unsealing position. A knob is carried by but rotatable relative to the top closure member. The knob and the actuating member cooperate such that rotation of the knob causes movement of the actuating member from a first position in which the outer edge of the bottom closure member is in sealing contact with the inside wall of the container to a second position in which the actuating member moves the central portion of the bottom closure member downwardly to disengage the outer edge of the bottom closure member from the inside wall of the container. The actuating member may comprise a pusher rod integrally formed with the knob. A cam system may be provided in part on the top closure member and in parts on the knob.

Description

This invention relates to containers and container closures, in particular to open-mouthed or open-ended storage containers for solid and liquid foodstuffs with a closure which provides a seal for the container.

One known form of container closure comprises a bottom closure member which is biased by its own natural resiliency, such that an outer edge will sealingly engage the inside wall of an open-mouthed container. The known closure includes a top closure member interconnected with the bottom closure member and an axially movably plunger extending through the top closure member. Manual pressure is applied to the plunger to push it axially against the bottom closure member. This causes distortion of the bottom closure member and a reduction in its diameter whereby the outer edge is displaced away from the inside wall of the container and the seal is broken. In this state the closure can be positioned in or removed from the open-mouthed container.

It has been recognised that problems exist with this type of closure, one of which is that relatively hich pressure or force has to be applied to the plunger in order to enable the closure to be positioned in or removed from the container. Further it is essential that finger pressure be maintained on the plunger at all times during removal from or refitting to the container.

To solve these problems it is proposed in US Patent 4303171 to provide the bottom closure member with an upwardly extending buttress member. The top closure member has a toggle or rocker connected to a cam member which under finger pressure on the toggle or rocker pivots into contact with the buttress to move it downwardly and thereby distort the bottom closure member. However, this arrangement still suffers from the disadvantage that finger pressure has to be maintained whilst the closure is removed from or refitted to the container.

An alternative proposal which does not suffer from this disadvantage is disclosed in US Patent No. 4295578. This describes a closure with a lever pivotally connected to the top closure member. The lever can be pivoted between a position in which it is lies against the top closure member to an extended position, the lower "pusher" end of the lever thereby being arcuately displaced against a central portion of the bottom closure member to distort it.

In all the above described arrangements, unsealing is achieved by pressing down on the bottom closure member. Closures are known however, as shown for example US Patent No. 2966276, where the bottom closure member is moved to the sealing position by application of pressure to its centre. In the sealing position the bottom closure member is concave with respect to the interior of the container. Application of pressure by a plunger extending through the top closure member causes it to be depressed through its dead centre, such that it is convex in the non-sealing position. A problem with this is that there is a danger that the bottom closure member will be unstable and flex back from its sealing to its non-sealing state or vice versa independently of any action by the user.

European Patent Application No. 0022277 discloses a closure of the above described type which is intended to allow control over the sealing force and prevent inadvertent release of the seal. The top closure member has a threaded downwardly extending boss which engages with the correspondingly threaded upwardly extending boss on the bottom closure member. Rotation of the top closure member relative the bottom closure member causes the two to be moved together or apart thereby adjusting the inclination of the region of the bottom closure member around the upwardly extending boss and thus the sealing force on its outer edge. This arrangement suffers from the disadvantage that it is relatively complicated and therefore expensive to manufacture. It also relies on the user correctly setting the relative positions of the top and bottom closure members to give the necessary sealing pressure. Further, there is a danger that the closure as a whole will rotate relative the container and cooperating dogs and recesses have to be provided to prevent rotation of the bottom closure member with respect to the container mouth.

A particular problem which exists with the number of the above described closures is that these are suitable only for circular containers, as they rely on substantially uniform radial stretching of the closure bottom wall. It is proposed in US Patent No. 4295578 that this problem be solved by providing a seal bead on the outer edge of the bottom closure member which has varying thickness for polygonal containers and closures. The bead is thicker where the stretching effect of the arcuately moving lever is greater and vice versa, so that disengagement of the bead occurs at substantially the same time around the closure member. This is a somewhat complicated solution to the problem however and requires that a different bead be provided for each different shape of closure and possibly also for each size of a given closure shape.

One object of the present invention is to provide a closure which is effective, no matter its shape, whilst using a common form of bottom closure member, that is, without requiring multiple bottom closure members with different thickness beads on their outside edges.

Another object of the present invention is to provide a closure which effectively seals the container without requiring excessive finger pressure so that it can be used by the young and the old and which does not necessitate the continuous application of pressure to maintain the closure in the non-sealing state.

It is a still further object of the invention to provide a closure with an operating member which does not protrude in the sealed and/or unsealed state to allow for ready stacking of containers fitted with such closures.

Yet another object of the present invention is to provide a closure which comprises a small number of easily manufactured parts which are not vulnerable to damage through repeated sealing and unsealing.

A closure member for an open-mouthed container in accordance with the invention comprises a resilient bottom closure member, the outer edge of which is sealable against the inner wall of the container, a top closure member connected to the bottom closure member, an actuating member for moving the bottom closure member from a sealing position to an unsealing position, and a knob carried by but rotatable relative to the top closure member, wherein the knob and actuating member cooperate such that rotation of the knob causes movement of the actuating member from a first position in which the outer edge of the bottom closure member is in sealing contact with the inside wall of the container to a second position in which the actuating member moves the central portion of the bottom closure member downwardly to disengage the outer edge of the bottom closure member from the inside walls of the container.

The use of a rotary motion for sealing and unsealing of a closure transmitted through a knob allows sufficient downward force to be applied on the bottom closure member to cause distortion of the same without requiring a high turning force and without the vulnerability to failure which can exist with known lever arrangements.

The actuating member in a preferred embodiment comprises an axially movable plunger rod located between the top closure member and the bottom closure member, the knob, top closure member and plunger rod cooperating such that rotation of the knob relative the top closure member causes axial movement of the plunger from the first to the second position and vice versa. The plunger location means that it does not, as in at least one known arrangement, protrude from the top closure member and stacking is readily possible particularly if, as is also preferred, the knob is located in a recess in the top closure member.

The plunger rod may engage an upstanding boss centrally provided on the bottom closure member. The boss may assist in locating the plunger rod on connection of the members of the closure. Distortion occurs in the region of the bottom closure member around the boss. The height of the boss can vary dependent on the closure size to allow a single length plunger rod to be used with differently sized closures, the boss ensuring force transmission to the bottom closure member.

Alternatively or additionally, the plunger rod may carry a plate at the end which acts on the bottom closure member. The plate will vary, the force applied across the bottom closure member from one section thereof to another to allow accurate sealing and unsealing even with a non-circular closure. This is a very significant development, as appropriately shaped plates can readily and simply be constructed for different closure shapes and the complicated systems employed in the art to deal with non-circular closures are avoided.

Very preferably the knob has at least one cam follower or cam track and another closure part has at least one cam track or cam follower, engagement of the cam follower(s) and track(s) causing movement of the actuating member from the first position to the second position and vice versa on rotation of the knob relative the top closure member. The knob may have at least one cam follower and the top closure member may include an angled cam track. It has been found that a very effective system in terms of force transmission results from the provision of three cam tracks and corresponding followers equally spaced around the top closure member and the knob.

The actuating member may be integrally formed with the knob. This has the advantage that the closure includes only a small number of parts.

Stop means may be provided for limiting the rotation of the knob with respect to the top closure member. Orientation means may be provided for correctly locating the knob with respect to the top closure member to facilitate assembly of the closure. The stop means may have structure in common with the orienting means.

Latch means may also be provided for locking the knob against rotation relative the top closure member with the actuating member in the first and/or second position. The latch means may have structure in common with the stop means.

Suitably the top closure member has an overall domed shape concave with respect to the interior of the container. One or more concentric rings may be provided on the upper surface of the top closure member to facilitate stacking of a container fitted with the closure to another container having a correspondingly domed closed end.

The invention will now be further described by way of example with reference to the accompanying drawings in which:

Figure 1 is a prospective view, partly cut away, of a container with a closure in accordance with the invention;

Figure 2 is an exploded view of the container and closure of Figure 1;

Figure 3 is a bottom plan view of a top closure member of the closure of Figure 1;

Figure 4 is a sectional view taken along the line A-A of Figure 3.

Figure 5 is a top plan view of a knob of the closure of Figure 1;

Figure 6 is a top plan view of an alternative embodiment of the closure of Figure 1.

Figure 7 is a transverse sectional view of the closure and container of Figure 1 in the unsealed state;

Figure 8 is a transverse section through the closure and container of Figure 1 in the sealed state, and,

Figure 9 is an exploded view of another container and in accordance with the invention.

The closure member 2 shown in Figures 1 and 2 comprises a top closure member 4, a bottom closure member 6 and a knob 8. It is used to close the open mouth 10 of a container 12.

The top closure member 4 is annular to define a central open-ended recess in its top wall 14. Three concentric

annular walls

16, 18, 20 extend downwardly from the top wall 14. The outermost wall 16 is of constant height and has a rib 22 extending around its outer surface.

The bottom closure member 6 comprises a diaphragm 24 having integral side walls 26 and a peripheral sealing rib 28 sealable against the inner side walls of the container 12. The top edge of the side walls 26 is shaped as a lip 30 which is snap fit over the rib 22 of the top closure member 4 to connect the top and

bottom closure members

4, 6 together.

The top and

bottom closure members

4, 6 are connected together with the knob 8 positioned therebetween whereby the knob 8 is held captive with a central upstanding boss portion 32 which carries a grip piece 34 located in the recess of the top closure member 4. A skirt 36 surrounds the boss portion 32 and is shaped to provide three sloping tracks 38. Each track 38 ascends in a gradual slope clockwise around the knob 8 to a cross piece 40. The cross piece 40 is divided into two

regions

40A and 40B, the first region 40A sloping up to the second region 40B which is flat.

The inner wall 20 of the top closure member 4 is divided into three sections 42, each of which has a constant height region 42A, an angled region 42B and then a shorter constant height region 42C, see Figures 3 and 4. Each section 42 has a lower edge 44 with two flat sections 44A and 44C separated by an angled edge 44B which is sloped correspondingly to the tracks 38. An abutment edge 46 is defined at each intersection between the sections 42.

With the parts of the closure 2 connected the side wall of the boss 32 lies closely adjacent or abuts the inner wall 20 of the top closure member 4. The skirt 36 of the knob 8 has an outer circular flange 48 which extends generally parallel to the side wall of the boss 32. This flange 48 lies closely adjacent the middle wall 18 of the top closure member 4 except at a 100° cut-out 50 formed by a reduced height portion of the middle wall 18. A tab 52 carried on the outer flange 48 of the knob 8 is received in the cut-out 50 when the parts of the closure 2 are correctly oriented. Location of the tab 52 in the cut out 50 assists in correct orientation of the knob 8 relative the top closure member 4 on connection of the closure parts. Abutment of the tab 52 against the edges of the cut-out 50 limits the rotation of the knob 8 relative the top closure member 4.

The top closure member 4 and knob 8 are additionally provided with further cooperating structure to prevent rotation of the latter relative the former. The structure comprises three ribs 54 equiangularly spaced around the flange 48 of the knob 8, the middle wall 18 having three pairs of corresponding ribs 56 equiangularly spaced therearound, each for receiving and trapping a rib 54 of the knob 8.

As discussed above, the closure 2 is assembled by connecting together the top and

bottom closure members

4, 6 with the knob 8 held therebetween and oriented relative the top closure member 4. In the sloped edges 44B of the cam sections 42 of the inner wall 20 of the top closure member 4 are received against the correspondingly sloped surfaces 38 of the skirt 36 of the knob 8 and the knob 8 fits in the top closure member 4 with the grip portion 34 forming in effect a continuation of the surface of the top wall 14 of the top closure member 4. In this orientation the cross pieces 40 sit against abutment wall 46 with flat regions 40B engaged with flat edges 44C of the wall 20. A frictional fit may be formed to latch the knob 8. This would be in addition or an alternative to engagement of the ribs 54 of the knob 8 d with the pairs of ribs 56 of the top closure member 4 to lock the knob 8.

In this position a pusher rod 58 which downwardly protrudes from the boss portion 32 of the knob 8 does not touch or bears only lightly on the diaphragm 24 of the bottom closure member 6. Preferably there is light contact with an upstanding rib 60 on the diaphragm 24. The diaphragm 24 and particularly the portion around the boss 60 is relaxed and fully distended, in which state the rib 28 will sealingly engage the inner side walls of the mouth of the container 12.

To break the seal and allow removal of the closure 2 from the container 12, a user grasps the grip 34 and rotates the knob 8 relative the top closure member 4. The ribs 54 on the knob 8 are disengaged from the pairs of ribs 56 on the top closure member 4. Simultaneously the cross pieces 40 travel across the cam edges 44B of the cam sections 42 of the inner wall 20 of the top closure member 4 and the knob 8 is thereby moved downwardly relative the top closure member 4. This in turn thrusts the plunger rod 58 against the boss 60 to distort the diaphragm 24, contracting its periphery and drawing inwardly the rib 28 to break the seal between the closure 2 and the container 12.

A 90° rotation, see double-headed arrow B of Figure 3, is required to fully distend the diaphragm 24 to the unsealed position. The shape of the cam slides 44B is such that the torque required to distend the diaphragm 24 is minimised and is graduated across the rotation. At the extremity of the rotation, the flat platforms 40B of cross pieces 40 may frictionally engage the flat edges 44A of the wall 20 to form a snap lock which will hold the closure 2 in the unsealed position, the arrangement being such that only a small torque action is required to release the snap lock. The snap lock means that the user can remove the closure 2 from the container 12 and refit it without having to maintain a torque on the knob 8.

Once refitted, the snap lock is released by turning it slightly. Due to its inherent elastic memory the diaphragm 24 then distends to its normal position with the sealing rib 28 in sealing contact with the inner wall of the container 12. The closure 2 may then be locked in the sealed position by turning the knob 8 to latch the ribs 54 on the knob 8 with the ribs 56 on the top closure member. An audible indication of sealing may be provided by forming the knob skirt 38 with cut outs 61 shaped to produce "living hinges" which flex on turning the knob 8 under pressure from the cross pieces 40 and emit a "click" on release of the pressure. In addition, the top wall 14 of the top closure member 4 may have visual position indicators 62 marked, for example, "open" and "lock" to show respectively that the closure 2 is in the unsealed and sealed states when the grip piece 34 is aligned therewith.

As will be appreciated, particularly from Figures 7 and 8, the knob 8 is lowered relative the upper surface of the top closure member 4 to move the closure to the unsealed open position in which it can be removed from or fitted to the container 12. As noted above, in the sealed lock position it forms through the grip piece 34 a continuation of the upper surface. This facilitates stacking of containers 12 fitted with the closure 2. It will be appreciated that the upper surface need not be domed, as illustrated, but may instead be flat as in the embodiment of Figure 9 discussed below,, in which case the grip piece 34 is appropriately shaped to provide a continuation of that flat surface. However, the domed shape gives a pleasing aesthetic appearance for circular container. To facilitate stacking and provide a resistance against toppling of a stack of containers 12, with domed closures 2, the containers 12 are provided with a domed closed end 64 as illustrated in Figures 7 and 8. To further assist stacking and resist toppling, the top wall 14 of the top closure member 4 may be provided with one or more rings 66 complete or extending around at least about 270°, the height, diameter, slope and location of the rings 66 being designed to interlock with the domed closed end 64. The rings 66 may also be located to hide possible shadowing from the middle and

inner walls

18, 20 of the top closure member 4 if translucent resins are used and/or surface sink marks from moulding during formation of the top closure member 4. Still further, the rings 66 may be sized and shaped to facilitate stacking of smaller containers on larger containers, the larger containers' closures being provided with one or more rings 66 sized to receive the closed end of a smaller container in a relatively close fit and so to restrain the smaller container from toppling.

The top closure member 4 may have a flat outer lip 68, the bottom surface of which engages a top bracing rib 70 at the mouth of the canister 12. The intersection between the domed top wall 14 and the lip 68 provides a location for an annular flange 72 forming a continuation of the side walls of the container 12 and extending beyond the domed closed end 64. The engagement provides still further enhancement of stackability and resistance to toppling of a stack of containers 12.

The top bracing rib 70 provides support to the mouth of the container 12 as well as a smooth inner edge. The walls of the container 12 may be shaped therebelow to define a platform 74 for seating of the closure 2. The platform 74 may have plural teeth 75 formed thereon spaced around the container 12 to produce an anti-rotation track with a corresponding anti-rotation track being provided on the bottom closure member 6. Interlocking of the teeth 75 of the tracks enhances the engagement of the closure 2 with the container 12 at the platform 74 and provides resistance to slippage or rotation of the closure 2 relative to the container 12.

It may not be necessary to have full anti-rotation tracks on both the container 12 and the closure 2. One may be formed with only a relatively small number of teeth set at 60° part. In any event at least one track preferably has teeth 75 with a slightly domed upper surface to facilitate interlocking engagement.

The closure 2 and container 12 of Figures 1 to 8 are circular. However, many of the features can be employed in non-circular closure and container combinations, as is illustrated by Figure 9. Like parts of the triangular container and closure combination shown there will be identified by like reference numerals.

The triangular closure 2 shown in Figure 9, like the circular closure 2 of Figures 1 and 2, includes a top closure member 4, a bottom closure member 6 and a knob 8, the last shown somewhat schematically. It additionally includes a plate 78 interposed in use between the knob 8 and the bottom closure member 6. The plate 78 serves to disperse the thrust applied by the knob 8 on rotation of the same relative the top closure member 4 such that greater pressure is applied to the regions relatively more distance from the central region of the bottom closure member 6 below the knob 8 and vice versa. This effect can be enhanced by providing buttons 80 on the underside of the plate 78, in particular at the corners thereof. The dimensions of the plate 78 and location and numbers of the buttons 80 are chosen such that there is uniform contraction of the bottom closure member 6 around its edges and therefore simultaneous displacement of the sealing rib 22.

The plate 78 is provided with a central upstanding boss 82 which is contacted in use by the pusher rod 58 and serves to transmit thrust from the rod 58 to the plate 78 and thence to the bottom closure member 6. It will be appreciated that the knob 8 requires a more complicated mould than the plate 78. An advantage of the provision of the boss 82 is that this allows the use of a single mould for the knob 8 and thus constant length pusher rod 58 for all sizes of container 12, as the necessary force connection can be achieved by varying the height of the boss 82 through the provision of a number of relatively simpler moulds for the plate 78 and boss 82. The same is true of the boss 60 on the bottom closure member 6 in the first embodiment where no plate is provided. The bottom closure member 6 may have an anti-rotation track formed by plural teeth 75 spaced around the member 6 at the corner of the side walls 26 to enhance the engagement with the base and side of the platform 74 and resist possible slippage or rotation of the closure 2 relative to the canister 12.

The three parts of the closure 2: the top closure member 4, bottom closure member 6 and knob 8 can be moulded from any suitable thermoplastic elastomer resins, for example, polyethylene, polycarbonate, polypropylene, general purpose styrene and styrene acrylonitrile. The chosen material should obviously meet the required standards for food contact. The bottom closure member 6 is preferably annealed in the mould to "freeze" the diaphragm 24 and increase its resistance to stretching or permanent deformation under the pressure of the pusher rod 58.

The closure 2 is easy to operate by all manner of persons including the young and the old, by virtue of the grip portion 34 which can readily be grasped and the contouring of the cam slides which enables sufficient thrust to distend the diaphragm 24 through minimum torque application by a user. The thrust action is directed downwardly which is most effective for diaphragm distortion.

The pressure on the diaphragm 24 can be adjusted by varying the cam draft angle, increasing the length of the pusher rod 58, or more preferably the

boss

60 or 82, such that the diaphragm 24 is under pressure even in the sealed state, or by use of a non-rotating pressure dispersion plate 78, as illustrated in Figure 9. It is also possible to vary the amount of rotation required to move from the sealed to the unsealed position by varying the number of cam sections 42. It will also be appreciated that the knob 8 could simply rotate relative the top closure member 4 and the cam connection be provided between the pusher rod 58 and

boss

60 or 82.

The closure 2 allows stacking of canisters fitted therewith in both the open unsealed position and the locked sealed position because the knob 8 does not protrude in either position. The two positions are visually indicated and an audible indication of sealing is provided. The knob 8 is latched in both positions by snap locks. This means that the user does not have to apply continuous torque on the knob to maintain the closure 2 in the open unsealed position which facilitates use of the closure 2 and also provides reassurance against inadvertent opening of the closure 2.

Stacking of containers fitted with the closure is also facilitated by the provision of the ribs 66 on the top wall 14 of the top closure member 4 of the closure 2 which engage the outer surface of the closed end of the container 12. In addition, the provision of a flange 72 on the closed end of the container which engages the top closure member 4, either on a flat lip 68 as illustrated in Figures 7 and 8, or an outer ring 84 as illustrated in Figure 9, provides further stability on stacking. The triangular container and closure combination of Figure 9 also allows multiple containers to occupy minimal space, as they can be arranged with the large angle apex 86 pointing oppositely on alternate containers and the container axes either horizontal or vertical, or six such container and closure combinations can be arranged with their large angle apices 86 pointing towards each other to form a hexagonal shape.

Claims

A closure member for an open-mouthed container comprising a resilient bottom closure member, the outer edge of which is sealable against the inner wall of the container, a top closure member connected to the bottom closure member, an actuating member for moving the bottom closure member from the sealing position to an unsealing position, and a knob carried by but rotatable relative to the top closure member, wherein the knob and the actuating member cooperate such that rotation of the knob causes movement of the actuating member from a first position in which the outer edge of the bottom closure member is in sealing contact with the inside walls of the container to a second position in which the actuating member moves the central portion of the bottom closure member downwardly to disengage the outer edge of the bottom closure member from the inside wall of the container.
A closure member as claimed in Claim 1 wherein the actuating member comprises an axially movable plunger rod located between the top closure member and the bottom closure member, the knob, top closure member and plunger rod cooperating such that rotation of the knob relative the top closure member causes axial movement of the plunger rod from the first to the second position and vice versa.
A closure member as claimed in Claim 2 wherein the plunger rod engages an upstanding boss centrally provided on the bottom closure member.
A closure member as claimed in Claim 2 wherein the plunger rod carries a plate at the end which acts on the bottom closure member.
A closure member as it claimed in any preceding Claim wherein the knob has at least one cam follower which engages an angled cam surface on another part of the closure, the engagement causing the movement of the actuating member on rotation of the knob.
A closure member as claimed in any preceding Claim wherein the top closure member defines at least one cam track and the knob has at least one cam follower engaged with the cam track.
A closure member as claimed in any preceding Claim wherein the actuating member is integrally formed with the knob.
A closure member as claimed in any preceding Claim further comprising stop means for limiting the rotation of the knob with respect to the top closure member.
A closure member as claimed in any preceding Claim further comprising latch means for locking the knob against rotation relative to the top closure member with the actuating member in the first and/or second position.
A closure member as claimed in any preceding Claim wherein the top closure member defines an open ended recess in which the knob is located.
A closure member as claimed any preceding Claim wherein the bottom closure member has a lip on its outer edge which is snap fit over a rib provided on the outer edge of a top closure member to connect the two together with the knob and actuating member held therebetween and thereby to mount the knob relative the top closure member.