Closing device for a container

The invention relates to a closing device for a container with an opening, in particular for a cooking pot with an outwardly protruding pouring edge, said closing device comprising a lid for closing the opening of the container, a closing element arrangement with at least a first closing element, and a movement device for moving the first closing element, said first closing element being able to be moved in an inward direction upon actuation of the movement device and moving upward at least in parts during the inwardly directed movement.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a closing device for a container in general and for a cooking pot or steam pressure cooking pot in particular.

2. Description of Related Art

At a time of increasing health awareness, there is also a greater demand for food preparation methods which are advantageous from the point of view of nutrition. At the same time, in a hectic world in which people want to and are able to spend less and less time on everyday household chores, there is a desire for fast and efficient food preparation. Steam pressure cooking pots satisfy these two apparently conflicting requirements outstandingly by permitting rapid and gentle cooking of food.

In principle, steam pressure cooking pots have been known for decades. However, the known steam pressure cooking pots have a number of disadvantages.

From the fifties, for example, and more specifically from patent specification DE 896 409, a steam pressure cooking pot is known with a lid which is closed by means of three jaws gripping round the edge of the lid. A disadvantage of this closure mechanism is that a substantial force is needed for closing it, this force being applied via an unwieldy lever.

More recent developments in the field of steam pressure cooking pots are described in laid-open specifications WO 96/01070, EP-A-1 029 483 and EP-A-1 082 932, for example.

A closure device which is known from laid-open specification WO 96/01070 has a lid with two radially displaceable clamping jaws which are drawn together by a spring mechanism. A disadvantage here is that a seal is prestressed in an undefined manner by pressing vertically on the lid before the clamping jaws are closed. The clamping jaws then slide abruptly inward and cause an annoying noise when they strike the pot edge.

Laid-open specification EP-A-1 082 932 discloses a steam pressure cooking pot with a similar lid as in document WO 96/01070.

U.S. Pat. No. 5,613,424 discloses a control device for opening and closing closure jaws for a pressure pot. The device comprises a control element which is mounted on a lid and, engaging in movement arms, moves radially with respect to the lid.

Furthermore, patent specification CH 254 203 describes a steam pressure cooking pot with an outwardly protruding edge. The lid of the steam pressure cooking pot comprises three gripping members which are bent in a U shape at their ends and which engage under the edge and press the lid with an interposed seal against the top face of the pot edge.

The document FR 2 809 608 A1 discloses a closing and opening device for a lid of a steam pressure cooking pot, which lid has four arms with clamping jaws which are driven by rotation of a control element.

In addition, laid-open specification EP-A-1 029 483 discloses a lid for a pressure pot with four movable clamping jaws which can be moved radially via a crank mechanism. This crank mechanism comprises a large number of movable components, some of them made of plastic. This crank mechanism is therefore complicated and expensive to produce and assemble, is not long-lasting, and is problematic with regard to hygiene requirements.

All of said devices have, however, further serious disadvantages in common.

The devices mentioned are cumbersome, esthetically unappealing, difficult to clean, and have to be produced with small tolerances.

SUMMARY OF THE INVENTION

In addition, a further serious disadvantage is that the known devices can be used only on specially adapted for moving at least the first closing element, preferably all of the closing elements.

The container has an axis which extends from a base to the opening and which in the case of circular containers in particular constitutes the axis of symmetry of rotation of the container. The axis preferably extends perpendicular to the container base.

The container moreover has an opening plane which is defined by the pouring edge and which preferably extends parallel to the container base and perpendicular to the axis. The first closing element or the closing elements is/are directed inward or moved toward the axis by an actuation of the movement device, and, during the inwardly directed movement or displacement, there occurs an upward movement, or movement away from the container base, of at least a portion of the closing element or closing elements.

This movement or displacement, in particular directed obliquely inward and upward, of the closing element or closing elements advantageously ensures a controlled downwardly directed pressure of the closing device onto the container or cooking pot, in particular for the defined prestressing of a seal arranged between the lid and the container.

Moreover, a reliable closure is ensured by the upward movement of the closing element or of the closing elements even in the case of considerable production tolerances. The closing device according to the invention is also especially suitable for commercially available cooking pots with an outwardly protruding pouring edge which is angled obliquely downward in the outer area. For cooking pots like these, most of the known lids for steam pressure cooking pots are not suitable, because their clamping jaws in most cases move horizontally, i.e. parallel to the opening plane or perpendicular to the axis. If known closing devices of this kind were nevertheless to be used in an inappropriate way, they would engage on the outermost, downwardly projecting portion of the pouring edge, i.e. with substantial leverage, and would possibly bend the pouring edge out of shape.

By contrast, the closing element of the closing device according to the invention is able to engage farther inward in relation to the pot axis. For this reason, the closing device according to the invention can cooperate with commercially available cooking pots, including those with relatively thin walls, resulting in a steam pressure cooking pot arrangement that is able to withstand pressure.

In particular, the closing element arrangement defines at least an open position in which the closing device can be removed from the container, and a closure position in which the lid seals the container, in particular in a substantially liquid-tight manner.

The container sealed off in the closure position is preferably able to withstand pressures up to at least about 5 bar internal pressure or internal overpressure.

In the open position, the closing element or closing elements is/are preferably in a first, in particular outer position, and, in the closure position, the closing element or closing elements is/are preferably in a second, in particular inner position, and it/they can be moved or displaced between the first position and second position. The movement or displacement between the first position and second position takes the form in particular of an inwardly directed radial movement in which the first closing element or the closing elements slides/slide on the lid.

The first closing element has in particular an outer edge for engaging on the pouring edge of the container. Upon the obliquely upward and radially inward movement of the first closing element, the outer edge comes to bear from underneath on the pouring edge of the container and, through the upward component of the movement, impacts the pouring edge with an axially upwardly directed force component.

The outwardly protruding pouring edge particularly preferably has an outwardly extending, substantially horizontal inner ring portion and a downwardly or obliquely downwardly extending outer ring portion. By means of the obliquely inward and upward movement of the first closing element upon closure of the container, the outer edge of the closing element can bear, at least in parts, from below on the inner ring portion of the pouring edge. The bearing point or ring is preferably situated as far inward as possible, e.g. on the inner half of the inner ring portion, so that the lever conditions are optimized and only a slight torque is exerted on the pouring edge. In particular, the bearing point or ring is not situated on the outer ring portion of the pouring edge.

According to a preferred embodiment of the invention, the outer edge of the closing element comprises a downwardly extending first portion and an upwardly extending second portion, the second portion being arranged to the inside of the first portion with respect to the container axis. The second portion ascends, for example perpendicularly or obliquely inward in relation to the opening plane.

Between the first portion and second portion there is preferably a third portion, which preferably extends substantially parallel to the plane of the pot. Upon closure of the closing device, the second portion in particular of the outer edge of the closing element comes to bear with force on the inner ring portion of the container, so that the closing device and with it possibly also the seal are pressed onto the container. In this case, the closure position is particularly preferably held with self-locking through the frictional forces generated.

It has proven particularly advantageous, and it is therefore preferred, to have an angle in the range of 5° to 30°, in particular in the range of 10° to 20°, most preferably in the range of about 15°, between the obliquely upwardly directed movement of the outer edge of the closing element, upon closure, and the opening plane of the container.

The seal is in particular designed as a sealing ring and preferably extends in a circle about the closing device. The seal is preferably attached to the lid in a releasable manner and is made for example of silicone or silicone-containing material.

It is particularly expedient to use what is called a sealing lip or lip seal, which has a substantially U-shaped or V-shaped cross section. The lip seal has the particular advantage that the pressure generated in the inside of the container forces the seal apart and thus improves the sealing action. Thus, relatively slight prestressing, as is generated by the closing operation, is still sufficient to achieve a closure that is very resistant to pressure.

According to a preferred development of the invention, the closing element has substantially the shape of a segment of a circle.

In particular, however, the segment tip can be removed or cut out. The circle segment shape is advantageous particularly in connection with an arrangement consisting of a plurality of preferably identical closing elements.

In the closure position, the closing elements particularly preferably form a substantially closed covering, by virtue of the fact that the circle-segment-shaped closing elements laterally adjoin one another, preferably flush with one another. There are preferably 2, 3, 4, 5, 6, 8 or more closing elements used. An optionally remaining central opening in the arrangement of closing elements is preferably covered from sight by a handle which is part of the movement device, so that in the closure position the impression given is of a conventional pot lid. In particular, in the closure position the lid is covered or concealed more or less completely by the closing element arrangement.

The lid and/or the closing element arrangement are preferably bulged outward at least in parts and preferably each form a sphere portion. In this embodiment, the closing elements preferably lie flat on the lid and slide on the latter. A radius in the range of 100 mm to 1000 mm, preferably in the range of 300 mm to 600 mm, has proven particularly expedient for the curvature of the sphere portions.

The closing element arrangement and the lid can preferably be connected to one another in a releasable manner by a central securing means, for example a screw. This makes it much easier to thoroughly clean the closing device.

The closing device, in particular the lid, preferably has centering means, for example projections extending downward from the lid. In the open position and/or the closure position, the centering means ensure a reliable and precise centering of the closing device, in particular of the lid, on the container.

The movement device preferably comprises a slotted guide disk secured on the handle, for example. In addition to having an axial bore, the slotted guide disk has, for each closing element, a curved slot extending obliquely to the circumference of the slotted guide disk. In the slot there is a bolt which is connected in fixed position to the corresponding closing element. By turning the slotted guide disk, the bolt is thus radially displaced with the closing element. Alternatively or as a complement to this, a toothed gear arrangement can also be used.

It is particularly preferable for the closing device, excluding the handle, to be made, in particular completely, of metal, for example of stainless steel. This gives a sturdy, long-lasting and hygienic closing device in which the coefficients of expansion of different component parts are adapted to one another and to the container.

Moreover, the closing device according to the invention preferably comprises a safety means with a blocking means for blocking the movement of the closing elements and/or an overpressure relief valve, in order to meet the legal safety requirements. Such safety means are known in principle to the person skilled in the art.

The invention is explained in more detail below on the basis of preferred embodiments and with reference to the figures.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1shows an embodiment of the closing device1according to the invention with a closing element arrangement2, comprising four closing elements10,20,30,40which are substantially in the shape of segments of a circle, and a rotationally symmetrical and rotatable handle50which is arranged centrally with respect to the closing device1. Each of the four closing elements10,20,30,40has in each case a central arc-shaped cutout12,22,32,42and in each case two mutually adjoining cutouts14d,14a,24a,24b,34b,34c,44c,44dwhich are arranged at the outer corners of the closing elements located on the circumference.

In the closure position of the closing device1shown inFIG. 1, the cutouts12,22,32,42substantially form a central circular cutout4of the closing element arrangement2. The cutouts14d,14a,24a,24b,34b,34c,44c,44dform four cutouts6a,6b,6c,6darranged at 90° along the circumference of the closing element arrangement2.

The four closing elements10,20,30,40each have two radial edges16d,16a,26a,26b,36b,36c,46c,46dand in each case an outer arc-shaped edge area18,28,38,48.

The closing element arrangement2is preferably first produced in one piece and shaped and then cut by means of a laser or a saw into four equal closing elements10,20,30,40. The laser cutting is particularly advantageous, as this avoids deburring.

The closing device1has been cut open in the area S so that a cutout of a slotted guide disk60and of a retaining and guide plate70can be seen.

The diameter of the closing device is about 240 mm, and the thickness of the closing elements is about 1 mm to 1.2 mm.

FIG. 2shows the closing device1in a side view along the direction C inFIG. 1. This view includes the two closing elements20and30, the handle50, and a lid80which is arranged inside the closing element arrangement2. The lid80has four centering tabs82a,82b,82c,82dwhich are arranged in the cutouts6a,6b,6c,6dof the closing element arrangement2, and of which the rear centering tab82dis not shown.

FIG. 3Ashows the closing device1in the closure position (solid lines). An edge area140of the closing element40is also indicated in the open position by broken lines. The other closing elements10,20,30are essentially identical to the first closing element40.

FIG. 3Aalso shows a movement device90comprising the handle50made of plastic, the metal slotted guide disk60, the metal guide plate70, a screw92, a drive pin94, a guide screw96, a central screw98, and a central nut99.

The handle50comprises a rotation knob52and a finger protection plate54. The guide plate70is arranged between the slotted guide disk60and the closing element40and is completely concealed by the handle50.

The guide screw96connects the closing element40to the guide plate70, the closing element40being radially displaceable with respect to the guide plate70. Upon the displacement, the guide screw96slides in a radially extending oblong hole71in the closing element40. The drive pin94connects the closing element40to the guide plate70, likewise in a radially displaceable manner, with the drive pin94sliding in an oblong hole72of the guide plate70. The is drive pin94further extends through a curved oblong hole64in the slotted guide disk60. The mechanism of displacement for the other three identical closing elements10,20,30is of equivalent design.

By turning the handle50about an axis122and the slotted guide disk60secured on the handle50, the closing element40is displaced radially between the open position and the closure position by means of the drive pin94.

Fig. 3Bshows a movement device90comprising the handle50made of plastic, the metal slotted guide disk60, the metal guide plate70, a screw92, a drive pin94having a toothed gearing94a, a guide screw96, a central screw98, and a central nut99.

The guide screw96connects the closing element40to the guide plate70, the closing element40being radially displaceable with respect to the guide plate70. Upon the displacement, the guide screw96slides in a radially extending oblong hole71in the closing element40. The toothed gearing94aof drive pin94connects the closing element40to the guide plate70, likewise in a radially displaceable manner, with the drive pin94sliding in an oblong hole72of the guide plate70. The toothed gearing94aof drive pin94engages a curved oblong toothed gearing64aof the slotted guide disk60. The mechanism of displacement for the other three identical closing elements10,20,30is of equivalent design.

By turning the handle50about an axis122and the slotted guide disk60secured on the handle50, the closing element40is displaced radially between the open position and the closure position by means of the toothed gearing64a,94a.

The closing element arrangement2and the lid80can be easily separated from one another by removing the central nut99, for example for cleaning purposes.

An enlargement of the edge area140is illustrated inFIG. 4in the open position.FIG. 4shows a circularly extending lip seal110. The lip seal110is made of silicone and is of substantially U-shaped cross section. The lip seal110comprises a central portion112and an upper lip portion114and lower lip portion116. The central portion112and the upper lip portion114lie from inside and from below against the lid80. The lower lip portion116comes to bear on a pouring edge130of a pot120of circular cross section, when the closing device2is fitted onto the pot or cooking pot120.

The closing element40has a lid portion49which curves outward in relation to the inside of the pot, and a claw-like edge portion140for engaging around the pouring edge130. The surface of the lid portion49is in the shape of a spherical portion with a radius of about 400 mm. The claw-like edge portion140has a first downwardly extending portion142and a second upwardly extending portion144. Here, the terms downward and upward are to be understood extending in the path of the closing element40away from the center or the axis122. Arranged between the first portion142and the second portion144, there is a third portion146, which according to this illustrative embodiment is horizontal. The second and third portions144,146are arranged inward in the direction of the axis or pot axis122in relation to the first portion142, and under the lid portion49. The closing element40is made of metal, in particular of stainless steel sheet, and the edge portion140is bent, rolled or beaded, so that curved portions141,143and145are obtained between the portions49,142,146and144of the closing element40.

The pouring edge130of the pot120has an inner ring portion132extending horizontally, or parallel to the pot surface121, and a downwardly beveled outer ring portion134.

In this embodiment, the centering tabs82a,82b,82c,82dare produced in one piece with the lid80and are indicated by broken lines inFIG. 4.

FIG. 5shows a detail of a sectional view corresponding to a section along the line B—B inFIG. 1.

FIG. 5illustrates an alternative embodiment of the centering tabs. A centering tab82cis shown which has been secured, for example welded, from the outside onto the outer edge of the lid80.

FIGS. 6athrough6cshow the movement of a closing element40′ which has been modified compared to the closing element40. The closing element40′ comprises an outer, downwardly extending first portion142′, and an obliquely upwardly extending second portion144′. Adjoining the second portion144′ there is a substantially horizontally extending end portion148′. Curved portions141′ and143′ are also present.

FIG. 6ashows the closing element40′ in the open position. During closure, the closing element40′ slides on the lid80in direction D.

It is obvious that the second portion144′ and the end portion148′, together with the whole closing element40′, move upward during the inward closing displacement. As can best be seen fromFIG. 3, the angle α between the direction of movement of the end portion148′ is about 18° in these illustrative embodiments.

FIG. 6bshows the closing element40′ or closing device1in a half closed position, in which the inner portion144′ already overlaps the pouring edge130of the pot120in part.

Referring now toFIG. 6c, the closing element40′ or closing element arrangement2is shown in the closed state or closure state. In the closure state, the second portion144′ of the closing element40′, or more exactly the inner horizontal end portion148′, bears with force on the pouring edge130. It is obvious that, by means of the oblique upward movement of the closing element40′, a perpendicular or axial force is exerted on the lid80and lip seal110, so that a defined prestressing of the lip seal110is obtained. In particular, the seal110is automatically prestressed when the movement device90is actuated to effect closure.

The point of engagement of the horizontal inner portion148′ lies relatively far inward on the pouring edge130, in this illustrative embodiment within the center of the inner ring portion132. In this way, the torque on the pouring edge130is kept low, with the result that the closing device1can even be used for pots120with a pouring edge thickness of less than 1.2 mm or less than 1.0 mm.

FIG. 7shows a fourth embodiment for the form of the outer edge of the closing element. According to this fourth embodiment, the outer edge140″ comprises an obliquely upwardly and inwardly extending second portion144″ with an end portion148″ which is bent downward in an arc shape and comes to bear on the pouring edge in the closure position.

FIG. 8shows a plan view looking at the center of the closing device without the handle50. This view shows the slotted guide disk60of stainless steel with four curved oblong holes61,62,63,64which do not extend parallel to the circumference of the slotted guide disk60and thus, upon rotation, radially displace the drive pins94and, with them, the four closing elements10,20,30,40.

FIG. 9shows a safety means150with a blocking device and integrated overpressure relief valve. The safety means150comprises a housing151, a screwed connection152, a valve pin153, a valve spring154, a valve ball155, and an O-ring156.

If the internal pressure in the closed pot rises above a first threshold value, the valve pin153is pushed upward through an opening in the closing element40, so that the closing element arrangement2is blocked and can no longer be opened. If the pressure rises above a second threshold value, e.g. 5 bar, pressure is released automatically via the valve ball155.

It will be clear to the skilled person that the invention is not limited to the embodiments described above and that instead it can be varied, particularly in relation to the concrete design of the outer edge of the closing elements and of the pouring edge, without departing from the spirit of the invention.